This PDF file contains the front matter associated with SPIE Proceedings Volume 12302, including the Title Page, Copyright information, Table of Contents, and Conference Committee Page.

With the rapid development of modern society, the important parameters of comfort air conditioning measurement technology testing and intelligent requirements are becoming higher and higher. When the HVAC parameters are tested and controlled, the number of various test components used is large. When the test components fail or the measurement error is distorted, the comfort air conditioner cannot operate automatically. At the same time, some of the measured parameters cannot be acquired directly by the test element. In order to solve this kind of problem, in recent years, air conditioning researchers have put their research direction into soft measurement technology, which has made a qualitative leap in the testing and intelligence of comfort air conditioning parameters. This paper studies the application of soft sensor technology in comfort air conditioning test from reality.

The medium voltage diesel emergency power supply vehicle has the advantages of convenient movement, large capacity, reliable power supply, etc. And it has been widely used in the distribution network failure recovery scenario. Due to the differences in control and communication methods between medium voltage diesel emergency power supply vehicles of different brands and capacities, there are many problems in parallel operation of medium voltage diesel emergency power supply vehicles. This paper analyzed the key problems of parallel operation of medium voltage generator vehicles from three aspects: abnormal conditions of parallel operation, simulation modelling and operation control, and multi-machine parallel control terminal. Finally, some specific solutions were proposed.

As the scale of the transmission system continues to expand, the structure and fault characteristics of the grid become more and more complex, and the existing fault diagnosis methods have difficulty in extracting the fault characteristics accurately in the face of the complex grid. A convolutional neural network (CNN) based fault diagnosis method is proposed. Firstly, the network structure is tested step by step through layer-by-layer filtering and layer-by-layer incremental stacking, with the aim of building a network structure fully adapted to grid fault diagnosis; then the training parameters are adjusted by optimization strategies; finally, an AC transmission system model is built on the MATLAB/SIMULINK platform, and the diagnostic effect is demonstrated by combining the network with the fault diagnosis. It is proved that this method has a high diagnostic accuracy and also reduces the number of fault samples, which is more in line with the practical needs.

For a bogie of a suspended monorail vehicle, the strength of the bogie frame is analyzed. First, the three-dimensional model of the frame is modelled and the material parameters are determined. Then the model is imported into Hypermesh for preprocessing. Then, according to standard BS EN 13749-2011, UIC515-4 and dynamic calculation results, the exceptional load cases and service load cases are established, and ANSYS is used to assess the static strength and fatigue strength of the frame. The results show that the safety factor of each point of the frame is greater than the allowable safety factor and the stress of all fatigue assessment positions of the frame is within the fatigue limit diagram, and the frame strength meets the standard requirements.

The helical vortex is formed in the draft tube of Francis turbine under partial load condition, which has an adverse effect on the safe and stable operation of the turbine. In order to study the correlation between the flow field at the runner outlet and the variation of vortex in the draft tube, the influence of the circumferential velocity and meridional velocity at the runner outlet on the vertex shape is analyzed through the simulation and experiment method. The results show that the meridional velocity at runner outlet has positive correlation with the diameter of the vortex. The vortex volume decreases with the decrease of the low meridional velocity region at the runner outlet. Decreasing the standard deviation of the circumferential velocity at the runner outlet is conductive to decrease the pressure fluctuation amplitude and its hydraulic loss in the draft tube.

In this paper, the wing is used as a cantilever beam to establish a structural motion model of swept wing, and the aerodynamic model of swept wing is established by modifying Theodorsen's aerodynamic force with Bisplinghoff's aerodyne-mic force correction method. Considering the effect of the ratio of the tip to the root, the mode of the swept wing was solved. The differential equations of the swept wing system were obtained by Galerkin method. The flutter critical velocity and flutter frequency of the swept wing were solved by an example

The previous fault line selection method usually used the zero-sequence signal after the fault to select the fault feeders, but the connection of the arc suppression coil reduces the fault current and the fault zero-sequence component, which makes the fault line difficult to select. For the distribution network with mixed cables, the performance of the zero-sequence current flowing through different types of non-faulty lines is also quite different. These circumstances obstructed fault line selection. In this paper, the voltage transient process after fault is analyzed in detail. After a single-phase grounding fault occurs in the system, the characteristic frequency band of fault voltage is extracted by discrete wavelet decomposition, and the comprehensive wavelet energy ratio representing the transient content of fault voltage is constructed to select the fault line of single-phase grounding. Simulation experiments of the algorithm are analyzed by PSCAD / EMTDC, and the results show that the proposed algorithm can accurately and reliably select the faulty line.

Due to its advantages of moderate capacity and small footprint, urban monorail transportation is attracting more and more attention. As the skeleton of the bogie, bogie frame directly affects the safety and stability of the monorail whether its structural strength meets the design requirements. This paper focuses on a suspended monorail bogie frame, and evaluates whether the frame strength meets the design requirements through the bench test and according to the standard UIC615-4 and EN13749. Using hydraulic servo system to carry out static strength loading and three-stage fatigue strength test cyclic loading. The test results show that the static strength and fatigue strength of the frame meet the design requirements, and the fatigue test of the frame is qualified.

In the operation of a high-capacity condenser system, its supporting pipeline often has the problem of abnormal vibration. Taking the rotor lubricating oil supply pipeline of a condenser, its maximum vibration speed can reach 277mm / s. This study puts forward a complete set of cause analyses and treatment schemes for pipeline vibration of condensers. Firstly, the primary vibration mode of pipeline vibration is calculated by the finite element analysis method; Then, combined with the actual vibration of the pipeline, the possible causes of vibration are analyzed; Finally, the corresponding shock absorber design scheme is given. The measured data show that this scheme can change the natural frequency of the pipeline system to avoid resonance and significantly reduce the pipeline's vibration speed. It provides a theoretical reference for designing and maintaining relevant condenser pipeline systems.

With the rapid advancement of the economy and society, the demand for an uninterrupted, reliable supply of energy within power systems is increasing. However, fault current is much smaller than load current during single-phase ground fault, making it difficult to detect the fault, which could lower the power quality. To ensure the high-reliable power supply, this paper proposes a SPG fault location technology based on the norm of current fault components. This technology obtains the phase-current signal through Feeder Terminal Unit (FTU), and uses the phase-current subtraction before and after the moment of the fault to obtain the current fault component, avoiding the influence of the load current on the fault characteristics. At the same time, the positive-sequence, negative-sequence, and zero-sequence currents are obtained according to fault components. Then, the ratio of the norm of the column vectors is calculated, and the magnitude of the result against the adaptive threshold is then calculated to complete the distributed ground fault location. Finally, ATP (Alternate Transients Program) simulation is used to verify the reliability of our proposed technology.

The combustion phase of a homogeneous charge compression ignition (HCCI) engine fueled with n-butanol/diesel blends was investigated on a 2-cylinder direct injection naturally aspirated and four-stroke engine at speed of 1000 r/min under different blending ratio and excess air ratio. The results show that with the increase of n-butanol/diesel volume content in the blends, the ignition timing of HCCI combustion retards under constant excess air ratio and the combustion duration shorten. When the blending ratio keeps constant, the the ignition timing brings forward with decrease in excess air ratio while the combustion duration has no significant difference, except for the blending ratio of 95%.

When the high-speed railway and the normal-speed railway are adjacent to each other, the ground return current generated by the high-speed railway autotransformer feeding system will cause instantaneous AC interference to the cables buried near the normal-speed railway. By establishing a simulation model, the influence of the high-speed railway autotransformer feeding system in normal operation on the induced electricity of the adjacent three-core power cable of the ordinary speed railway is studied, and the relationship among the distance between the cable and the high-speed railway, parallel length of cable and high-speed railway, soil resistivity, traction, current and induced current are explored. Finally, the parallel sections of typical high-speed railways and ordinary railways are selected for actual measurement under the conditions of single-end grounding and double-end grounding of cables respectively, and the simulation model is verified. The results show that there is a significant relationship between induced current and high-speed railway electric traction supply system current. The induced voltage is within the safe voltage limit during normal load operation.

The plateau railway has especially tough condition compared to the normal railway, due to the effects from permafrost, high altitude, low temperature and some other extreme environmental condition. Thus, it is critical to assure the transportation capacity of the locomotive as well as the safety of train dynamics during transportation. To study the performance of locomotives on a plateau railway, this work investigates three sets of newly-developed diesel locomotive which are reconnected to pull 4000t of cargo on the Qinghai-Tibet Railway Gera section. The train operation is simulated considering the vehicle dynamics in lateral and longitudinal directions, with traction and braking conditions. The results from a simplified trainset model show that the traction capacity of the three locomotives can meet the requirements of freight transportation. The maximum hook force on the coupler can reach 1250kN at the starting condition, and the maximum pressure hook force on the coupler is 704kN in the long downhill cyclic braking condition, meeting the safety requirements. Using multi-body dynamics software, a detailed locomotive dynamics model is established, enabling the analyses for lateral dynamics of the locomotive. The simulation results show that the dynamic performance of the locomotive can meet the requirements under the maximum pressure state. The reduction of the free deflection angle of the coupler is beneficial to improve the dynamic performance of the reconnected vehicle. This paper provides a reference for the research on the adaptability of locomotive transportation in railways.

Aiming at the problem of uneven illuminance distribution of light source array on the surface of dot matrix LED dynamic speed limit sign. In this paper, the distribution threshold of single LED effective illumination value and the superposition distribution model of lattice light source illumination are established through the derivation of basic optical theory and the experimental test of grating aperture isolation method, and then the influence of the theoretical and measured distance between two LEDs on the illumination distribution uniformity of LED array light source is simulated and analyzed by using optical software Trace/Pro. The rectangular LED dot matrix and the 8-shaped LED dot matrix, which is a common element in the speed limit value of the dynamic speed limit sign, are simulated and analyzed with the established lamp bead spacing. The results show that the distance between two light beads plays a key role in the distribution uniformity of illumination. When the central distance between two light beads is 22 mm, the distribution uniformity of illuminance in the central area of the light source and the overlapping area of radiation light from two LED light beads reaches 95.2%, which meets the requirement that the unevenness of speed limit signs should not be greater than 10%.

For production-oriented enterprises characterized by multiple varieties and small batches. To improve its overall equipment effectiveness. Single Minute Exchange of Die technology in lean production as a theoretical guide. Based on H Bathroom Technology Company. Research on Single Minute Exchange of Die for H Bathroom Technology's injection molding machine equipment in the injection molding workshop. By analyzing the wastefulness of mold change time. Conduct a series of optimization and improvement measures. This includes distinguishing between internal and external operations and reducing their duration. Optimize mold change process, optimize staffing and path planning. Good results were achieved. The results of the study showed that the average mold change time of injection molding machine equipment in the injection molding workshop was shortened from 81 minutes to 34 minutes, and the overall efficiency was improved by 58%.

The scheduling problems of production lines like buffer allocation problems (BAP) are usually NP-Hard problems and are complex to deal with using traditional techniques, especially for large-scale production lines disturbed by such stochastic events as the breakdown of machines. For large-scale production lines consisting of unreliable machines, the hierarchical decomposition parallel optimizing technique (HDPOT) is proposed here. The technique combines with the aggregation method of the hybrid production line to decompose the original production line into n+1 subsystems by following some principles. Moreover, the asymptotic optimum solution of the original production line is gotten by searching parallel the optimum solutions of the subsystems. Meanwhile, an improved simulated annealing algorithm is proposed for the parallel optimization of subsystems. The HDPOT finally is tested by an example of buffer allocation problems (BAP) and specified by numerical experiments. The results show that this technique can solve scheduling problems more accurately, especially for large-scale production lines.

To explore the influence of dynamic characteristics of sealing gaps on the pressure fluctuation in train during passing through a tunnel, static air tightness test is conducted to calculate the equivalent leakage area of gaps and to investigate the dynamic characteristic with the variation of pressure difference. The dynamic leakage process of gaps when passing through a tunnel is simulated numerically and the impact of gaps on leakage flow and internal pressure is analyzed. It is found that 1) the equivalent leakage area of gaps has nonlinear characteristics with different pressure difference, 2) when a train under operation condition with positive pressure, the air is more likely to flow out through the holes under positive pressure, 3) the external section of the hole is obviously impacted by the incoming flow, and the stress condition is worse than other parts, 4) the maximum leakage flow of dynamic equivalent leakage hole, the one second change rate, the three second change rate and the amplitude of the pressure inside vehicle under the model are equal to 43.33%, 55.73%, 45.62% and 48.60% of the fixed equivalent leakage hole, respectively. This study can provide a reference for the determination of equivalent leakage area of high-speed train and the optimization of sealing technology.

In order to reduce the energy consumption problem of distributed 4WD electric vehicles, a torque distribution strategy based on energy consumption optimization is proposed. Firstly, the dynamics of the distributed 4WD electric vehicle is analyzed, and the forward simulation model of the distributed 4WD electric vehicle is established in combination with the European cyclic conditions; secondly, based on the analysis of the energy consumption characteristics of the distributed 4WD electric vehicle, the mathematical model of the optimal torque distribution is established with the objective of reducing the energy consumption of the whole vehicle, and the objective function is optimized using the artificial fish swarm algorithm to obtain the torque distribution results when the energy consumption is optimal, and the total loss of the system is simulated in combination with the whole vehicle The simulation analysis of the total loss of the system is carried out in combination with the vehicle model. The simulation results show that the optimal torque allocation scheme obtained by the artificial fish swarm algorithm for distributed 4WD electric vehicles can effectively reduce the energy consumption of the whole vehicle.

Periodic motion in binary asteroid systems is fundamental to studying system dynamical behaviors and designing exploration missions. In this paper, we focus on the periodic orbits around collinear equilibrium points of the system. Third-order analytical solutions for three types of periodic motion (i.e., planar Lyapunov, vertical Lyapunov, and Halo orbits) are sought. Considering the mass distribution, we model the system as two triaxial ellipsoids, so the gravitational field consists of their ellipsoid potentials. Elliptic integrals analytically express high-ordered partial derivatives of the ellipsoid potential in preparation for the procedure. After utilizing the Taylor series to linearize the system's effective potential, we employ the Lindstedt-Poincaré method to construct the third-order analytical solutions. Features of three periodic motions help determine the unknown coefficients during the recursive procedure with elaborate manipulations. A good agreement is found between the analytical solution and numerical results for periodic orbits, except for the Halo case. We develop an extra scaling technique to correct the deviation, whose scaling factor is formulated by system parameters through a polynomial fitting procedure. The numerical simulation shows that the Halo approximated solution is also sufficiently accurate, covering binary asteroids within various parameter ranges.

CNC machine tools can process exquisite parts and complex parts, which are very practical for the machinery manufacturing industry. In recent years, with the development of computer technology, CNC machine tools have gradually developed to be controlled by computers. Computer-controlled CNC machine tools can effectively improve the quality and efficiency of production and improve the safety of industrial production. In this paper, a fully automatic integrated CNC machine tool system that can be controlled by a computer is established. This system has the function of automatic tool change of the manipulator with high safety, which improves the reliability of the machine tool system. It is more practical for business.

This paper analyzes the need for an integrated multi-station control system and conducts research on the construction of the integrated control system. With the design philosophy of “integration and sharing, intelligent interconnection,” it proposes a new network architecture for integrated monitoring of “platform integration, standardized access of all subsystems, modular operation and smart linkage” and control strategy for comprehensive energy station of “distributed autonomy, centralized coordination, multi-energy complementarity, and regional deployment.”

At present, although there are many achievements in theoretical research for the daily scheduling of microgrids, few dedicated computing tools can be applied to practical operations. In this article, we used a software tool CloudPSS-IESLab for day-ahead scheduling of microgrid system. Considering the uncertainty of wind-solar resources and fluctuation of electricity price, we have implemented the battery storage day-ahead scheduling in a real microgrid system. Compared with the battery schedule formulated by human experience, the result calculated by software CloudPSS-IESLab reduces the operation loss by about 80%, and significantly improves the economy of system operation. The study for this case also reveals the application prospects of CloudPSS-IESLab in energy systems with larger scale and more energy sources.

Facing the environmental problems caused by high carbon emissions, multi-energy coupling technology cooperates with carbon trading mechanism to achieve low-carbon operation of virtual power plant(VPP). This article firstly analyses the allocation method of carbon emission quota and the ladder-type carbon trading mechanism. Secondly, in order to realize low-carbon economic dispatch and multi-energy demand response (DR) of VPP, a VPP operation optimization model is established based on multi-energy coupling. Finally, a case is studied to verify the economic and environmental benefits of this model. The results show that ladder-type carbon trading mechanism can reduce the carbon emissions of the system.

As a key technology for the development of the new electric power system, low-voltage DC power distribution is gradually proceeding from theoretical research to engineering demonstrations and then penetrating to commercial applications. In this paper, a survey of the low-voltage DC distribution network is conducted from the perspective of the engineering practical application. The technical analysis of the topological structure, cooperative control strategy and fault protection is compared. An optimized design was performed for a low-voltage DC application in Xiong'an New Area that was successfully applied in the practical project. The scheme validation was completed by using the statistical analysis for the actual operating conditions, which provides practical experience in the development and construction of the low-voltage DC distribution networks.

In view of the new engineering construction mode of standardized design, industrialized processing, and modular construction carried out by the State Grid Corporation of China, a new commissioning and operation mode of substation relay protection "Replacing maintenance with replacement, and plug and play" is proposed to improve the efficiency of construction, operation, and maintenance. Following the principle of coordination and unification of "safety, applicability, universality and economy" and adapting to the integration trend of primary and secondary equipment of the power system, the protection configuration of the secondary system is optimized and adjusted in this paper.

The efficiency test of hydraulic turbine is one of the basic tests of hydraulic units. The efficiency characteristic of hydraulic turbine is the basic dynamic characteristic of units. The on-site efficiency test of unit four in a large capacity power station is carried out by using the ultrasonic method and the index method, and the actual efficiency characteristic curve of the turbine under the test head is obtained. According to the flow measured by the ultrasonic flowmeter and the volute pressure difference measured by the index method, the volute flow coefficient K and the index coefficient X are determined by the linear regression method to guide the economic operation of the unit.

In order to balance the capacity and energy difference of single battery in the battery pack, improve the energy utilization of the battery pack, and use the equalization circuit in the charge and discharge process of the battery pack. The energy dissipative circuit is balanced by shunting through the parallel resistance of single cells. The energy dissipative circuit structure of non energy dissipative circuit is relatively complex, which can be divided into energy conversion equalization and energy transfer equalization. Designing a simple and efficient voltage detection circuit is a problem that needs to be solved in the equalization circuit.

In order to solve the unbalanced between the heat supply of the heating system in the railway station area and the heat demand of various functional building, the problem of serious energy waste was caused. This paper proposed the time-space differential operation strategies that adopts the linkage adjustment between the heat source side and the building, and applied it to the railway station area to respond to the changing needs of the indoor temperature of each building in the railway station area. First, the heat source quality regulation operation strategy of the heating system in the existing railway station area was introduced. On this basis, respectively variable frequency water-mixing pump regulation to study the time-space differential operation strategies that can meet the needs of building indoor temperature. Then, taking the heating system of a railway station in Datong as an example, the simulation model of the heating system was established by Simulink. Finally, on the basis of verifying the high accuracy of the model. The dynamic response of indoor temperature and energy consumption of the system under three different operating strategies were compared and analyzed. The results show that the energy saving effect of heat source quality regulation + local variable frequency pump operation strategy is the best, and the energy saving rate is 41.43%. The heat source quality regulation + local variable frequency water-mixing pump operation strategy has the best indoor temperature regulation effect, and the indoor temperature qualification rate is 86%.

At present, when the size of low voltage distribution district exploded, the development of state assessment of low voltage distribution district became the daily operation monitoring of district, district reform, district governance. There were still many problems with the current low voltage distribution district condition assessment done by power grid enterprises, such as still relatively single evaluation index, too subjective or too objective evaluation methods, and the application of business system data in low voltage distribution district condition assessment was not deep enough. This made the assessment of the state of the low voltage distribution district relatively one-sided, which affected the overall results of the district's state assessment. It was often possible to extrapolate the whole picture from what was observed. This also directly led to unsatisfactory results or even significant deviations from expectations in the daily operation monitoring, district reform and district governance of the district. In this paper, the current status and problems of the low voltage distribution district were brought into focus, and a comprehensive evaluation method of the status of the power grid low voltage distribution district was proposed, based on the current level of business digitization in power grid companies, which combines subjective and objective evaluation and covers more indexes. The low voltage distribution district status comprehensive evaluation index system was built from seven dimensions, including district line loss and district power grid. Based on the application of the integrated weight method of AHP (analytic hierarchy process) and the inverse entropy weight method, the comprehensive quantitative evaluation of the status of low voltage distribution district was realized. In addition, the district data of a power grid enterprise was analyzed in a case study. The practicality and feasibility of the proposed method were fully verified.

This paper introduces the common methods of automobile braking performance testing, expounds the evaluation indexes and testing standards of automobile braking test-bed, and concludes that braking force is an important index for evaluating automobile braking performance. The basic structure and working principle of brake test bed, flat brake test bed and road test of roller reaction automobile are analyzed and expounded. According to the detection principle, this paper analyzes the common faults affecting the detection of automobile braking performance and the preventive measures.

By using structured, semi-structured, and unstructured data, combined with related algorithms for knowledge extraction, it is one of the current development directions of electric power technology to build a domain knowledge graph. The purpose of this paper is to study entity relation extraction and auxiliary disposal of power equipment fault defect text based on knowledge graph. The construction method of knowledge graph is studied, and the method of constructing a power equipment diagnosis system is used to assist in the disposal of power equipment faults, and the function of the power equipment diagnosis system is analyzed. The system defines 10 entity relationships according to the output of the power equipment fault entity. A method for derivation of power equipment fault entity relationship based on syntactic and semantic features is proposed. Finally, the extraction results of 10 kinds of entity relationships meet the actual use requirements.

With the improvement of the integration of digital circuit chips, its complex structure makes the failure model and failure mechanism more and more complicated, which brings more challenges to the fault detection and prediction of digital circuits. This paper analyzes the failure prediction methods of different data collection sources, divides the prediction methods into four categories, and introduces the failure prediction methods for different data collection. This paper introduces the BIC-based model ranking flow chart. The forecasting techniques based on the Autoregressive Moving Average (ARMA) model are highlighted. The 550 simulation results show that the ARMA model is in good agreement with the measured results.

In view of the frequent faults of capacitive voltage transformer in the process of putting into operation, an optimized probabilistic neural network method for fault diagnosis of capacitive voltage transformer is proposed in this paper. Based on the existing state data, the feature extraction parameters are modified to improve its classification accuracy, so as to realize the diagnosis and identification of common faults of capacitive voltage transformer. Compared with the traditional preventive experiment of power failure, it can find the potential equipment defects better. Finally, the simulation analysis shows that this method can be applied to the common fault diagnosis of capacitive voltage transformer.

The reliability of the power supply system is critical for the safe operation of metro equipment. How to make a reasonable maintenance strategy in terms of cost and performance control has become an important issue in operation and maintenance practice. At present, metro high-voltage circuit breakers mainly borrow from the equal period preventive maintenance strategy of the railway system. The lack of theoretical basis in setting maintenance periods may happen insufficient maintenance or excessive maintenance, resulting in the problems such as high maintenance costs and long maintenance time. To solve the above problems, an optimized maintenance strategy with unequal periods of the metro circuit breaker is proposed in this paper. Firstly, based on the maintenance data, a mixed failure rate function containing the age reduction factor and the failure rate increase factor is constructed. And a cost function model of metro circuit breakers under reliability constraints is established in a limited time. After that, the optimal preventive maintenance times and unequal maintenance intervals are determined with the minimum maintenance cost rate in the renewal cycle as the optimization goal. Finally, a case study is carried out for the high-voltage circuit breaker of a metro company. The results show that the maintenance cost rate is decreased by about 9.42%, and the maintenance time is reduced by approximately 34.73%, which verify the effectiveness of the proposed maintenance strategy.

Through the compatibility mode of HTML5 development and mobile native development, starting from the migration efficiency of native mobile applications, the security of power dispatching system and the convenience of data planning of power dispatching system, and through the cross platform characteristics of HTML5 and the multi-stage protection of network and native environment, this paper realizes a set of mobile application platform suitable for multi terminal integrated power dispatching.

The abnormal heating test model of GIS internal insulation was established. The abnormal heating test of aluminum-filled basin insulator under steady state current was carried out. The content of SO2, H2S and CO2 remained stable at the beginning of the experiment, and the content of SO2, H2S and CO2 increased obviously when the experiment reached a critical point. The abnormal heating test model of the inner insulator of the gas insulated switchgear was established. The overheat test of solid insulation was carried out under the condition of 0.3 MPa absolute pressure in the gas chamber and without adsorbent. The overheat fault duration was 6 h and the overheat fault temperature was respectively 200℃、250℃, 300℃ and 350℃, the decomposition products of SF6 are CO, CO2, SO2, SOF2, H2S, COS and CF4. The generation mechanism of SF6 decomposition products under abnormal conditions is also analyzed to guide the judgment of internal faults and operation defects of equipment on site and ensure the safe and stable operation of power grid equipment.

In order to improve the adaptability of high-speed trains to the changes of their own parameters and service environment, and improve the vibration response characteristics of vehicle system, a semi-active control strategy for secondary suspension of high-speed train was studied. A multi-rigid-body transverse-vertical coupling dynamic model of high-speed train based on Simpack was established. The relationship between the synthetic vibration and modal motion of the carbody was analyzed by using the concept of contradictory extent. A hybrid damping modal control algorithm was proposed. The decoupled carbody modal motions are controlled based on skyhook control, and a hybrid damping coefficient and a hybrid proportional weighting function are introduced to adjust the control proportion of each modal motion. The simulation analysis was carried out by using the established Simpack/Simulink co-simulation model. The results show that hybrid damping modal control can effectively suppress the motion of each rigid body mode of the carbody, improve the transverse and vertical running stability of high-speed trains, and will not cause any running safety problems.

Regarding the assembly problem of a dual-shaft hole in which the double hole of the refueling mechanism is simultaneously inserted into the dual-component propellant adding mechanism during the spacecraft refueling process, and under the condition that the state of the target refueling port may have uncertain changes, this paper proposes a new smart compliant assembly method based on deep reinforcement learning that applies TD3 to design the controller. With the output trajectory of the six-degree-of-freedom manipulator impedance controller as the reference trajectory, the deep policy gradient neural network is trained to determine the trajectory correction value, and the dual-shaft hole assembly process trajectory is optimized. Compared to the traditional compliant control method based on impedance control, this smart compliant control method can reduce the contact force of the assembly process and is adaptable to various shaft hole states, which is advantageous for the autonomous smart completion of on-orbit refueling tasks.

As the most critical part of the overall structure of imitation human robots, bionic waist joint needs to be good and flexible in addition to the basic motion function of the waist joint to ensure that when it is applied to imitating robots, it can be more consistent with the physiological characteristics of the human waist joint. This paper proposes a bionic waist joint system composed of two bionic waist joint units based on the 3-DOF (degree of freedom) parallel mechanism driven by pneumatic artificial muscle. The kinematic analysis of the bionic waist joint unit mechanism and system is carried out, respectively. For the non-linear characteristics of pneumatic artificial muscle, its mathematics model is optimized. The dynamics model of bionic waist joint is derived. For the bionic waist joint’s position control, the PID controller and the RBF-PID controller are designed, and the proportional integral differential (PID) control algorithm and radial basis function neural network (RBF) tuning PID parameter control algorithm are studied, respectively. The simulation results show that both PID control and RBF-PID control achieve a relatively ideal effect on joint position control, but the BPPID control algorithm is better than PID control.

In the current society, due to the rapid development of science and technology, the embodiment in the automobile field is more prominent. The car has changed from the initial manual transmission to the current automatic transmission, and at the same time, under the development of these technologies, the safety factor of the vehicle has also been greatly improved. Especially in the turning stage of the vehicle, in order to ensure the stability of the vehicle when bending, the driver needs to control the direction of the speed to stabilize the vehicle, to avoid the occurrence of safety accidents. Vehicle steering system is a convenient way for the driver to control the vehicle driving according to the driving intention, and the key subsystem to realize the stable vehicle driving (line-controlled steering technology). For the safety of vehicles, the emergence of line control system greatly improves the lightweight and intelligence of vehicles. Because the mechanical connection between the steering wheel and the steering assembly is cancelled, the steering wheel cannot receive timely feedback from the road information in some aspects. Therefore, the driver is required to form a sense of road on the road surface when driving the vehicle. The line control steering technology controls the vehicle steering through the line control signal, improves the steering sensitivity and low speed stability, and provides excellent hardware and intelligent ECU (electrical control unit), which is the basis of automatic vehicle steering. Compared with the traditional steering system, the wire-control steering system can not only control the stability of the vehicle, but also make the driver feel comfortable while driving the vehicle. After analyzing the stability parameters of the vehicle during the vehicle steering, a vehicle stability control scheme based on the linear active steering system is developed.

With the development of China's economy and science and technology, the car has become one of the essential necessities in people life, at the same time, with the development of artificial intelligence, Internet, computer information technology, automobile manufacturing in our country is developing towards the intelligent direction, the rise of advanced computer technology and the electronics industry provides great power, for the optimization and upgrading of automotive electronic control system provides a new technical support, making the development of the automobile industry more in line with the needs of the current era. This paper will analyze the application of computer control technology in automotive electronic control system.

For near-polar orbit satellite constellations with multiple orbital planes, the reconfiguration control of orbital planes is required, whether for multi-planar deployment during one rocket launch multi-satellites, for replacing satellites in the adjacent orbital planes after satellite failure, or for reconfiguring the constellation due to changes in mission requirements. To reduce the cost of orbital plane reconfiguration, this paper proposes a continuous small thrust based orbital plane reconfiguration control method for high inclination near-polar orbit satellite constellations. The orbital plane reconfiguration is achieved by changing the orbital inclination with continuous small thrust, using the difference in the change rate of the Right Ascension of the Ascending Node at different orbital inclinations under the influence of J2 perturbation; Finally, the effectiveness of the method proposed in this paper is verified by simulation. The simulation results also show that, compared with the method of directly changing the orbital plane, the method in this paper can significantly reduce the velocity increment required for the orbital plane reconfiguration, which has more practical significance.

The lateral control of the driverless vehicle is based on the steering angle of the front wheel as the control variable to track the desired trajectory. In this paper, a two-degree-of-freedom vehicle dynamics model is established. In order to reduce the amount of calculation, the original model is simplified accordingly. Then, a lateral controller based on model predictive control is designed, and the objective function is constructed and solved after its condition constraint. Finally, the joint simulation analysis of path position tracking and heading angle is carried out based on Carsim and Matlab / Simulink software. The simulation results show that the lateral controller can track the trajectory effectively.

Based on the path planning algorithm of the shore-based platform and the tracking algorithm of the guidance system, through the improvement of the sliding mode control, the stability of the state and speed of the unmanned vehicle when moving on the water surface is tested. This device uses stm32 chip of ARM company as the underlying processor, and controls the course and speed controllers according to the information instructions from the upper-level information acquisition equipment and industrial computer, so that the unmanned boat can complete operations on the water at the specified speed.

On the premise of in-depth application of the 3D platform and understanding of the underlying structure of the program, the research is carried out through the attribute assignment and fine modeling of the substation 3D electrical model and the civil engineering model, the formulation of detailed 3D verification rules, and the development of software customization to carry out real-time intelligent electrical distance check. After using the 3D intelligent verification application, the designer does not need to think too much about the safety distance. The realization of this technical means can optimize the layout of the power distribution device to the greatest extent under the premise of ensuring the design quality, which greatly improves the design level.

The chopper of IGBT electronic power switch is often used in the control of DC motor of electric vehicle. IGBT chopper is a periodic on-off switching device between DC power supply and DC motor. Using IGBT for power conversion can improve power efficiency and quality. IGBT combines the advantages of MOSFET and GTR power transistor, with low driving power and low saturation voltage.

The vertical roller mill (VRM) is a new type of grinding equipment, which is the preferred equipment for raw meal grinding globally. The grinding process has the comprehensive complexity of strong nonlinearity, multi-variable strong coupling, large lag, time-varying parameters and uncertainty, and the current research on the mechanism of the grinding process is not enough, so it is difficult to control the grinding system. This paper introduces the existing control methods: model-based grinding system operation optimization and control method, data-based grinding system operation optimization and control method, grinding system operation optimization and control method based on intelligent technology. The research results of the current control methods are summarized, and the problems to be solved in this research field and the future development direction are further prospected.

Substation automation system (SAS) based on IEC61850 is the direction of SAS, whose security risk assessment is meaningful. The function-based model (FBM) was proposed, by which SAS could be decomposed into functions and described in mathematical language, and the security risk of SAS is divided into system and function risk. A method calculating function failure probability is presented, logical connection, logical node and function value are defined to measure function failure consequence. Taking T1-1 SAS as example, the feasibility and applicability of the proposed method is verified.

In recent years, as the requirements of China's atmospheric environmental protection policies become more and more perfect and strict, there is an increasing demand for the treatment of "wet plume" formed after the saturated wet flue gas generated by the wet desulfurization and dust removal of power plant boilers is discharged into the urban atmosphere. This paper studies the application of automatic control system in the "wet plume" treatment of thermal power plant, and solves and optimizes the problems in the current "wet plume" treatment and transformation by selecting a reasonable automatic control system, so as to reduce the pressure of environmental protection and improve the use efficiency of primary energy.

To solve the problem of ship living area emergency cases, the ship and offshore illumination conditions, unable to timely find the socket pin and insert for power supply of equipment, application of TIRZ design theory, triangle TIRZ analysis model is set up, the innovation design a wall-mounted recessed guided insertion neat wiring strip. The product sample processing and customer experience using experiments were carried out. The experimental results show that the plug can quickly guide the operator to insert the circular plug into the target jack, which avoids electric shock, reduces anxious groping in the dark, and greatly improves the life efficiency and convenience of the crew.

Tidal energy is the kinetic energy created when the gravitational forces of the Moon and the Sun cause periodic reciprocal horizontal movements of seawater, mainly concentrated on shores, waterways between islands, or in the mouths of bays. Tidal currents can usually be classified as reciprocating or rotating, and are mainly the more steady flow in submarine waterways and straits as well as the regular flow of seawater due to tides. Compared to waves, tidal currents are much smoother and more regular. Tides can change in size and direction on average twice a day in response to the rise and fall of the tide. China has extremely rich marine resources, among which tidal energy is abundant, especially offshore tidal energy which is among the highest in the world in terms of power density, therefore the development and production of tidal power generators to improve efficiency and performance is an important step in the implementation of China's sustainable development strategy. Most of the existing tidal power devices are fixed directly to the seabed, which is more conducive to stable energy harvesting, but if the device needs to be installed farther offshore and in deeper water, a floating structure is required to facilitate installation and save costs. A new floating bi-directional tidal power generation device is proposed based on existing research examples and research project requirements, which converts tidal energy into electricity through three stages: energy capture, transmission, and generation.

As an important part of ensuring traffic safety of highway tunnel, highway tunnel lighting system has some problems such as high energy consumption and low degree of intelligence in its use. In this paper, a set of intelligent dimming system for highway tunnel lighting is designed, which takes the environmental variables such as luminance value and traffic flow information inside and outside the tunnel as input, establishes the intelligent dimming mathematical calculation model, adjusts the output power of the system in real time, and then adjusts the brightness of LED lamps. At the same time, the system connects with the remote management system through Ethernet remote communication technology, and can also realize the function of remote dimming. It improves the intelligent level of highway tunnel lighting and reduces the energy consumption of highway tunnel lighting system.

Metallic Zn anode is receiving increased attention due to its high safety and low cost. However, its practical application is limited by the dendritic growth and corrosive reaction. Herein, the electrochemical stripping/plating behaviour of metallic Zn was studied in the hybrid aqueous/organic electrolyte composed of 2 M Zn(OTF)₂ in polyethylene glycol (PEG)-H2O solvent with different volume ratios of PEG content ranging from 0 vol% to 50 vol%, in which the water activity decreased through altering its hydrogen-bonding structure with PEG. An optimized PEG content of 50 vol% enabled a dendrite-free Zn anode morphology during repeated plating/stripping processes. The mechanism of morphology was analyzed by scanning electron microscopy, cyclic voltammetry, and X-ray diffraction. And the corrosion-suppressive reaction was analyzed by linear polarization curves. Finally, the optimized Zn anode showed a high reversibility of stripping/plating behavior (1000 h), which contributed to the suppressed dendritic growth and corrosive reaction.

Focusing on the actual needs of the rapid development of the current unmanned intelligent equipment, this paper studies the evaluation indicator system of the unmanned intelligent equipment operational test. First, the similarities and differences between unmanned intelligent equipment and traditional manned equipment in operational test evaluation are analyzed. Second, the characteristics of unmanned intelligent equipment and the main content of operational evaluation are proposed. Finally, an unmanned intelligent equipment operational test evaluation system based on dynamic adaptive indicators is proposed. The related research in this paper can provide a theoretical basis for the subsequent evaluation of the operational test of unmanned intelligent equipment.

Suspension chopper is a high-power electrical equipment for vehicle suspension control. Its performance is crucial to the stability, reliability and comfort of maglev trains. There are a series of problems in the traditional chopper using the H-bridge hard switching mode, especially the problem of voltage spike which cannot be ignored for high-speed maglev trains. In this paper, a phase-shifted full-bridge zero-voltage suspension chopper is proposed, which uses the phase-shifted control signal to realize IGBT zero-voltage turn-on and zero-voltage turn-off, so as to reduce the voltage spike. Firstly, the working principle and control modals of the phase-shifted full-bridge suspension chopper are analyzed. Then, the simulation and experimental test platform are built to verify the effect of reducing the voltage spike. The results show that the phase-shifted full-bridge suspension chopper can effectively reduce the voltage spike, which provides a reference for optimizing and improving the high-speed maglev chopper.

In order to better realize the consistent teaching requirements of training and war, and truly achieve the integration of college teaching and army training, taking the navigation simulator as the support platform, the paper gives the overall idea of celestial navigation simulation training system under the simulated scene. The training method of simulated celestial body observation is constructed, and the observation accuracy and training results are evaluated according to the scoring standard. This method changes the traditional practice that celestial navigation training can only be implemented at sea. It is of great practical significance to realize the integration of college teaching and maritime equipment training, which can improve the quality and efficiency of celestial navigation training.

The location of catenary anchor leg single point mooring device is limited by the factors such as route, Anchorage, shipwreck, oil production platform, water depth, sediment and so on. The location model is established through the limiting conditions, and the location model is realized in a visual form based on Geographic Information system (GIS) and the mooring area that meets the operation requirements is obtained. Finally, the multi-attribute ideal reality comparison method (MAIRCA) is used to rank the suitability of the selected mooring areas. Taking a sea area in the Bohai Sea as an example, five areas satisfying the import and export mooring operation of 250000 dwt oil tankers are obtained, and the order of operation suitability of the mooring areas to be selected is as follows: region 5 ⪆region 4 ⪆region 3 ⪆region 2 ⪆region 1. It provides an intuitive and reliable decision-making scheme for port authorities and construction units to select the location of catenary anchor leg single point mooring device.

In the case that magnetic levitation (maglev) is required to enter the airport and GBAS VDB is used as a means of aircraft approach in the future, a reasonable layout between maglev line and GBAS VDB is sought. Take maglev vertical across the final approach path of an aircraft as an example. Based on the analysis of the practical measurement RFI data of maglev arc according to three working conditions of maximum power acceleration, maximum power deceleration and passing the test site at a constant speed, and considering the ground reflection of the maglev arc, the EMC of the maglev arc to the VDB signal is analyzed when the VDB is near the runway threshold and far from the runway threshold. The results show that the maximum radiation intensity range of maglev arc is from 56.20 to 57.76 dBμV/m. When the VDB antenna is close to the runway threshold, the protection ratio of the maglev arc to the VDB signal will not be less than 26 dB, unless the maglev is within 410 m from the runway threshold.

Sensor technology is a new economic and social development derived from the science and technology, the technology has been effectively applied in the development of various industries, and comprehensively improve the quality and efficiency of work, for the development and innovation of enterprises to bring more valuable work plan, promote the positive development of various enterprises. Effective application of sensor technology can collect the most real and effective information, while converting the specified measured non-electricity into the measured electrical signal. The use of sensor technology in mechanical and electrical automation control can further promote the development of the intelligent era, improve people's quality of life, drive the production of enterprises, and promote the information construction in China. This paper mainly analyzes the specific use of the sensor technology in the electromechanical automation control.

As the brain of driverless cars, behavioral decision-making module plays an important role. In recent years, reinforcement learning has been gradually introduced into this field. However, the algorithms proposed in many articles are only used to solve a certain scenario or a certain driving task, and cannot completely solve the unmanned driving in urban scenarios. Some articles try to use one framework to solve the whole urban scenario, which does not take into account the differences between individual scenarios in the city and has poor expansibility. In this paper we propose a hierarchical behavioral decision-making framework. In the top layer, we consider four typical scenarios in the city and adopt rule-based finite state machine (FSM) to realize reasonable switch between them, which makes the system have good expansibility. At the bottom layer, we train an agent for each scenario using reinforcement learning to realize deep traversal of the specified scenario to improve decision accuracy. First, FSM determines which scenario the car is in and then an according agent is selected to make decisions. Using SMARTS as the simulation environment, we test each agent in according scenario and the agent fused with our framework in urban scenario under free, stable and congested three traffic conditions. On the whole, the completion rate remains above 90% and the collision rate remains below 5% for every agent showing that our method is safe and effective.

Gravitational waves are ripples in the curvature of spacetime that propagate outward from the source of radiation through waves. In this paper, the basic principles of general relativity are discussed, including a brief derivation of gravitational waves, the gravitational wave equation, the means of gravitational wave detection, and the prospects for the future. In addition, this paper will demonstrate the observations of the gravitational wave GW151226 observed by LIGO, indicating its source data and other processed data. According to the analysis, the GW151226 event was produced by the merger of a black hole of 7.5 times the mass of the Sun with a black hole of 14.2 times the mass of the Sun, where the lost double solar mass was propagated as a gravitational wave. These theoretical and observational results clarify the reality of gravitational waves predicted in general relativity; however, this result is still criticized by a few scholars, which will be discussed accordingly. The future outlook for gravitation detection will be presented. These results shed light on guiding further exploration of gravitational wave detection.

Composite stringer is the main bearing structure of civil aircraft fuselage. The finite element models of hat-shape composite stringer and T-shape composite stringer under axial compressive loads were established by using ABAQUS software. Hashin criterion was introduced to describe the failure of the composites, and the buckling load and the crippling load of the composite stringers were calculated. The corresponding axial compressive tests of the composite stringers were carried out by electronic hydraulic testing machine. The test results were in good agreement with the finite element analysis results, which verified the rationality and accuracy of the calculation model. The numerical calculation method and results in this paper can provide guidance for the structural design of composite stringer in large civil aircraft.

As the core component of the camera, infrared focal plane detector assembly is widely used in the field of aerospace infrared remote sensing because of its excellent performance in thermal image viewing, forward-looking early warning, prevention and control monitoring, infrared recognition and so on. Aiming at the 4kx4k large area array infrared video circuit spliced by four 2kx2k infrared detectors, firstly this paper considers the difficulties of piecewise adjustment of integration time and sampling point position delay compensation of spliced detectors from the perspective of FPGA. Then the design idea is given, including configuring and using management chip to reduce clock jitter and improve the reliability of data transmission; the functions of programmable adjustment of pixel blind coordinates and real-time inconsistency correction are realized, and the image quality is improved; using DDR2 to store inconsistency correction parameters; finally, the channel image data synthesis and transmission are completed. All functions such as focal plane control, signal processing and plug-in chip control are completed with one FPGA, which has the advantages of miniaturization and lightweight. The test shows that the design idea and scheme in this paper are feasible and practical, which provides reliable technical support for video signal processing of aerospace remote sensing large array detector, and is of great significance.

According to the requirements of ground test task of lunar sampling manipulator, a microgravity simulation system based on suspension method is designed and developed. The system is mainly composed of Position tracking system, Force compensation system, Suspension system, Posture measurement system and Integrated control system. The simulation system has completed the ground test and ground verification of lunar sampling manipulator, which has been successfully launched, and successfully completed the on-orbit mission. The microgravity simulation system of manipulator has good universality and expansibility, and can be applied to the ground test of other space manipulator products.

The ball screw is a commonly used transmission component. When applied to the spacecraft mechanism, it is necessary to comprehensively consider space environmental factors such as on-orbit high and low temperature, vacuum, atomic oxygen, electron irradiation, single particle, ultraviolet and infrared irradiation. In view of the long-life application requirements of ball screws for spacecraft mechanism, the factors affecting the life of the ball screws are analyzed. Two design schemes are proposed according to the lubrication method of the ball screws and the material of ball for a ball screws of a certain spacecraft mechanism. The design scheme of ceramic ball + raceway sputtering MoS2 lubrication has been confirmed by the test. The design can work for no less than 7000 times under the specified load, which meets the requirements of the flight model on-orbit. Through the ball screw long-life test, it can be seen that the load capacity and service life of the solid lubricated ball screw are significantly reduced. In the development process of the spacecraft mechanism ball screw, a special life test must be carried out to verify whether the ball screw can meet the on-orbit requirements.

Management control system is an important component part of the remote sensing camera electronics system. CPU is commonly chosen as the core processor, which can control different devices and multiple working modes, and also satisfy the data transmit and process. For constructing a faster processing speed and more powerful platform, a combination of FPGA and CPU is designed. The powerful logical function of FPGA can assist CPU to control interface, drive and data acquisition. This design availably averts repeated uses of different interface circuit, decoding circuit and logic circuit, which is more beneficial to the miniaturization and reliability of the product.

The position and attitude equipment provides real-time measurement data of position and attitude for the vehicle- mounted aerospace TT&C system, and its accuracy directly affects the capture and tracking of the spacecraft by the entire system. In this paper, the coordinate model of the vehicle aerospace TT&C system is established, the influencing factors of the position and attitude equipment on the spacecraft tracking are analyzed, the influence of different measurement errors and vehicle body motion on the antenna tracking angle is simulated, and the measurement accuracy requirements of the position and attitude equipment and the vehicle's tracking angle are given. It has certain reference significance for the vehicle aerospace TT&C system to reasonably formulate the tracking plan and accurately and stably capture the target.

Increased aviation emissions in recent times has led to an urgent call for increasing aerodynamic efficiency of an aircraft by reducing drag. This paper focused on aerodynamic drag reduction through biomimicry of a sharkskin denticle through 3D printing the denticle and incorporating it on a NACA0012 aerofoil. The denticles are strategically placed in forward and backward directions at 16% and 60% of chord line of an aerofoil, respectively. Wind tunnel experiment results indicate that the denticles can successfully reduce drag by a maximum of 11.2% and enhance lift by 11.3%. Conditional results presented in the paper indicates that biomimicry has great potential for further aerodynamic performance improvement.

In the aircraft assembly process, the assembly deviation caused by positioning error, clamping force, hole making, connection force, residual stress, etc., will be passed along the assembly process to the final product, affecting the final assembly product deviation. With an assembly design based on tolerance allocation, increased manufacturing costs due to excessive dimensional requirements can be avoided, and further dimensional chain tolerance optimization can be performed.

Blended-Wing-Body (BWB) is a special aircraft design concept which combines the fuselage and wing together. The unique shape of blended-wing-body aircraft owns the advantages of high pneumatic efficiency, light structural weight and large capacity. Blended-wing-body not only saves energy and environmental protection, but also effectively reduces noise and harmful gas emission of the engine. In this paper, the effect of blended-wing-body nacelle’s installation angle of title and toe of the aircraft is studied by optimizing and analyzing. The changes of detachment area of flow on the surface of fuselage and nacelle are mainly researched. The nacelle’s installation angle of title and toe is proved to influence the elimination of flow detachment exactly.

Compared with traditional methods, biochemical reactions at the micro-scale have faster reaction rates and lower raw material costs, and multi-site array reaction vessels can better carry out controlled experiments and repeated experiments. However, the pressure drop of the fluid under the microchannel is very large, and it is necessary to ensure a good closed space and the design of the fluid inlet and outlet. Array reactors with a high degree of integration require the designer to reasonably allocate the three-dimensional space to ensure the air tightness of the microfluidic device while increasing the reaction points of the device as much as possible. At the same time, the material of the device should be selected to meet the biocompatibility of most reagents. Herein, a microfluidic array reactor made of polytetrafluoroethylene were developed and the solution delivery process was tested to verify its stability and air tightness. This study lays the foundation for the application of microfluidics in biochemical reactions.

It is important to extract road automatically in photogrammetry. But it is difficult to extract from images. Here we use mobile laser scanning point clouds to extract road information. We use pos information to segment the point clouds around road. Boundary and road are classified by random forest classifier. Then intensity histogram was used to detect the road markings, threshold was calculated in the histogram by gaussian decomposition.

In solving the environmental problems caused by central heating caused by coal combustion, nuclear energy has been gradually applied to the field of heating that as a clean and safe energy. This paper discusses the advantages, development process, and specific application of nuclear heating. At the same time, taking the demonstration project of energy-saving transformation of nuclear heating in a domestic nuclear power plant as an example, a modular integrated heating device is applied. The working principle, operation technology, installation, and effect requirements of the modular integrated heating device are studied. Through this device, the external heating of auxiliary steam in the nuclear power plant is realized efficiently. It provides a case reference for the use of nuclear heating and heating devices.

When the high power microwave power supply system works normally, the magnetron has higher requirements for the filament power supply. In order to solve the problems of long response time and unstable output voltage of filament power supply, This work applied UC3842 as a current mode PWM generator component to construct a single-ended forward filament power supply with AC208V input and DC5V output. And the working principle of the main circuit and the design of the control circuit are analyzed in detail. The validity of the circuit is verified by the simulation results.

There are many small hydropower stations in Jilin Province that only rely on the flood season to generate electricity and cannot operate economically and efficiently throughout the year. In view of this problem, combined with the abundant solar and wind energy resources in the province, wind power generation and photovoltaic power generation are added on the basis of existing small hydropower, and battery energy storage components are configured, and the optimal capacity configuration scheme of the power generation system is studied to construct a wind-solar-water power generation system. Storage complementary power generation system. The research results show that the development of an off-grid wind-solar-water-storage hybrid power generation system has a high investment cost and a long payback period, but it is still necessary and feasible to meet the electricity demand in remote mountainous areas.

This paper proposes a configuration method for islanded microgrid with wind, solar PV, gas turbine, and energy storage system. The objective is to minimize the annual cost of the microgrid. The microgrid's cost model is established, considering capital investment cost, operation and maintenance cost, and replacement cost. Configuration results with adopting lithium battery and compressed air energy storage under different renewable penetration are discussed. The configuration result shows that a microgrid with a compressed air energy storage system has a lower annual cost than a lithium battery.

At present, urban pipelines often have the characteristics of intricate pipeline networks. Using pipeline robots to inspect pipelines is a method with better safety, higher efficiency and lower cost. In this paper, a robotic arm control method with the smallest motion path is obtained based on the inverse solution of the robotic arm, and based on this method, a detection robot with a robotic arm and a camera that can be controlled remotely is implemented. The robot can perform high-pressure cleaning and other actions in the pipeline, and realize remote information interaction through the Wifi module, and display the pipeline screen, which is convenient for users to change the robot's motion state.

This paper proposes a new type of hollow ring permanent magnet power-loss protection brake integrated into the interior of the robot joint components. Compare to the ordinary brakes, in the case of power failure, the brake uses permanent magnetic to brake generated by rare earth NdFeB, which has the advantages of low power consumption, large self-locking moment, easy assembly, maintenance free etc. After energizing, the electromagnetic coil produces the reverse electromagnetic force to counteract the permanent magnetic force together with the spring force of the flexible ring sheet on the friction armature to ensure the rapid release of the brake in the braking position and achieve the separation of no residual torque. The hollow ring routing mode not only avoids the exposure of the wire that is affected by electromagnetic radiation, but also avoids the surplus of the required wire at each joint. The equivalent magnetic circuit model of the brake under power on and power off conditions is established respectively, based on which the permanent magnetic internal structure, electromagnetic field change and magnetic flux trend are analyzed. The change of magnetic flux and magnetic flux density in the working air gap in two working conditions is shown. Finally, the theoretical calculation results are verified by the finite element simulation software.

The Rubik’s Cube restoration robot takes STM32F103 processor as the platform, and the cube restoration function realized through mechanical system, control system, communication and image recognition system and actuator. The logic flow chart of the magic cube restoration process is drawn, and the communication interface and protocol between the upper and lower computers are designed according to the requirements of the control system. The acceleration and deceleration operation curve of the manipulator driving motor is optimized to improve the speed as much as possible on the premise of ensuring the operation stability. The vision system is realized through the coordinate transformation algorithm of color space and the adaptive light compensation function algorithm. Finally, through the installation, operation and debugging of software and hardware, the goal of solving and restoring the magic cube is finally realized.

According to the needs of pipeline inspection and cleaning in power industry, an omni-directional motion robot with a negative pressure adsorption is proposed. The robot can not only achieve the stable adsorption and movement of the vertical walls, but also has a brief structure, and high flexibility. Firstly, in consideration of the actual performance requirements of the project, we determined the scheme selection of different modules of the robot. Secondly, Maxwell module of ANSYS finite element analysis software was used to study the adsorption device, and an adsorption device with stable adsorption was obtained, which ensured the safe and stable operation of the robot on the vertical wall. Thirdly, the hardware system and control system of the robot are determined and the construction of the robot system is completed. Then the dynamics of the robot are analyzed, and the simulation is carried out according to the analysis. It is verified that under the control of PID algorithm, the acceleration of the robot can be in a stable state finally, which ensures the robot is stable in the process of motion. Finally, we finished experiments of the robot and verified the robot is stable whenever it works on walls.

Based on the characteristics of power battery, a power battery thermal management system with integrated liquid cooling plate and heating film was designed, and the system was simulated and analyzed. The results show that the system can effectively suppress the temperature rise of the battery module and keep the temperature within a reasonable range. At the same time, the heating temperature rise rate of the system reaches 30.44℃/h.

Reduce the use of SF6 gas to meet environmental requirements, to solve the problem of SF6 high voltage electrical equipment operating reliably at ultra-low temperature, SF6/N2 gas mixture is used as insulation or arc extinguishing medium, development of electric equipment for SF6/N2 gas mixture. Similarly, the higher the density of the SF6/N2 gas mixture in electrical equipment, the more insulated or arc-extinguishing it is. It is necessary to monitor the gas density, and also urgent to develop SF6/N2 mixed gas density relay to solve the problem of SF6 high voltage electrical equipment operating reliably at low temperature and ensure the safe operation of mixed gas high voltage electrical equipment. And it can achieve a better effect of energy saving and emission reduction. The higher the SF6 proportion under the same pressure, the stronger insulation capacity is. Therefore, it is necessary to develop SF6/N2 mixed gas density relay, this paper presents the development of high performance SF6/N2 mixed gas density relay, the realization method of high performance SF6/N2 mixed gas density relay is described. And Pass the performance test, It is proved that the SF6/N2 mixed gas density relay has good performance.

In SF₆ electric equipment, the moisture content of SF₆ gas is an important index to supervise the safe operation of the equipment. This paper introduces the source of water content in SF₆ gas and its harm when the water content exceeds the standard, and analyzes the influence of water content on decomposition products under discharge of solid metal particles and abnormal heat. In view of the excess water content in SF₆ gas, the corresponding control measures are formulated to ensure the safe and reliable operation of SF₆ equipment.

10kV large-capacity distribution systems are increasing, and the demand for high-current and high-voltage switchgear is increasing. The design of high-current and high-voltage switchgears lacks a relatively mature scheme, and the lack of a mature design scheme in busbar selection and structural design will bring many problems to the structural design, manufacturing and operation of switching equipment. Therefore, on the basis of the existing medium-mounted high-voltage switchgear, the structure of the high-voltage switchgear and the selection of the main busbar are studied. The connection scheme of the busbar, the installation of the current transformer, the space of the receiving cabinet and the installation mode of large size cable are also designed, the impact on the eddy current and the heat dissipation of the switchgear are also carried out. After full consideration, a high-current metal armored pull-out switching device with a rated current of 4000A is designed.

During the shipping process of LNG ship, crack expansion may occur in the main shield of LNG cargo tank, resulting in LNG leakage into the secondary shield drip tray of type B tank. Due to the large temperature difference between the LNG temperature and the external environment, evaporation and diffusion will occur in the process of leakage to the secondary shield drip tray. When the design of the secondary shield drip tray is unreasonable, the leaked LNG will overflow the drip tray and drip onto the hull, endangering the safety of the hull. Taking a liquid cargo tank of a LNG ship as the research object, this paper uses ANSYS simulation software to simulate and analyze the residual amount after evaporation in the process of LNG leakage to the secondary shield drip tray. The secondary shield drip tray can verify whether it meets the design requirements according to the LNG residue.

Defrosting technology plays an important role in the normal operation of air source heat pump units in winter. This paper briefly summarizes the main factors causing frosting of air source heat pump units, focusing on energy saving, environmental protection, low consumption and other issues. By using waste heat for two-stage heating, the development prospect of this technology is demonstrated by comparing various defrosting technologies.

As a simple and effective method, centralizer can directly improve the buckling behavior of casing in deep and ultra-deep wells. In this paper, an ultra-deep well in Shunbei block is taken as an example. Based on elastic-plastic contact theory and Abaqus finite element software, the finite element model of the wellbore and reconnection casing is established. The buckling behavior of the reconnection casing string under dead weight is analyzed, and corresponding schemes are designed according to its buckling behavior. The results show that, under the action of self-weight, the return casing produces a serious spiral buckling behavior in the wellbore, and the spiral buckling phenomenon of the casing string is significantly improved by applying a centralizer at the peak and trough of the wave caused by the buckling in the direction of U1 and U2. It is shown that the casing buckling can be avoided by adopting the centralizer placement design scheme, which provides some reference for the actual field study of the buckling behavior of the casing string and the optimization design of the centralizer.

With the continuous expansion of the application fields and application scale of embedded operating systems, the multitask software structure based on embedded operating system effectively reduces the difficulty of embedded software development, whereas the traditional design method for multitask embedded software might bring the problem of uncertainties such as deadlock and starvation. As an event-driven basic software framework, the quantum framework encapsulates the underlying embedded operating system, connects multiple active objects and hardware interrupt service routines, manages shared resources by special active objects, adopts asynchronous exchange of event instances, and provides event distribution mechanism. Thus, the multitask application software system based on the quantum framework can effectively avoid uncertain problems such as race conditions, priority inversion, deadlock, and starvation.

In the paper, in order to solve the problem of early warning and control of security risk under the intelligent connected scenario, based on the mixed traffic flow system observability analysis algorithm, the traffic security risk sensors optimized layout is proposed. Firstly, for the mixed traffic flow which contains connected autonomous vehicles and human driven vehicles, the model is established on the basis of different mixing rates. The system matrix calculation method is present, and the design schemes of the output matrix set is also developed. Secondly, based on each pair of the system matrix and the output matrix, the mixed traffic flow system observability is addressed and the optimized layout of traffic security risk sensors is completed as well. Finally, the highway is taken as an example to verify the proposed approach, the results show that the observability algorithm can provide technical support for optimized placement of traffic sensors, and more importantly, it can detect the existing security risk in time.

With the rapid development of economy, environmental problems have become increasingly serious. The emergence of prolonged hazy weather and carbon emission pollution in China has been a reminder of the importance and urgency of protecting the environment. The main cause of air pollution in China's port area comes from ship exhaust emissions. In 2016, the China Ship Control Zone set strict requirements for sulfur oxide emissions. To meet the emission requirements set by law, this paper analyzes the following two important emission reduction options: using ship desulfurization process and using low sulfur fuel oil (MGO). Comparative studies are conducted in terms of cost and environmental benefits, respectively, and the concept of investment-benefit ratio is introduced to comprehensively evaluate the payback capability of the two options. The findings of the study can provide a scientific evaluation basis for government departments and shipping companies to choose the ship emission reduction options.

Modern energy system presents the trend of "scenery leading and multi-source coordination". Accepting more fluctuating power supplies and loads with different characteristics puts forward higher requirements for the flexibility of the system, and the role of energy storage resources in the operation of the system is becoming more and more important. At present, the understanding of energy storage power stations is mostly limited to peak shaving and valley filling, easing the tension between power supply and demand and so on. In the future, the value of energy storage will be more reflected in realizing the dynamic balance between power supply and demand, smoothing output fluctuation and load change, improving the consumption of renewable energy, providing auxiliary services in the power market, so as to improve the safety, economy and flexibility of power grid operation and realize the coordinated and optimal operation of energy storage and modern power system.

The integrated energy system includes a variety of energy production and conversion equipment, which can realize the complementary operation of cold and hot electricity and improve energy utilization efficiency. However, at present, the research on the optimal operation of integrated energy system is relatively limited, there are few types of equipment and models, and the objective function of optimal operation is single. Therefore, this paper constructs a comprehensive energy system model covering energy production, conversion and storage, establishes a multi-objective optimization function of operating cost, carbon emission and primary energy consumption, and takes an industrial park as an example. The results show that the proposed integrated energy system can realize the coordinated operation of electric heating and air conditioning according to the energy price and supply, and the cost can be saved by 15.72% compared with the cost of sub supply system.

Early in the design of the AGV (automated guided vehicle), the calculation and analysis of its dynamic and economic performance are of great significance. This paper describes the process and results of theoretical analysis, and the accuracy of the theoretical analysis is verified by experiments. According to the analysis results, the dynamic and economic performance parameters can be calculated with the parameters of power and energy storage device. And the parameters of power and energy storage device can also be selected according to the dynamic and economic performance target parameters.

Studies have shown that at the end of 2025 there will be a 221 population of over 5 million cities in China, with conventional public transit having gradually become the first choice of urban residents. In the process of transporting passengers, it involves the shortest transfer route choice. In this paper, acquiring the Qingdao Jiaonan district’s bus IC card of residents to select the waiting time, walking time, and some other effective d5ata. From two aspects of transfer times and costs, with the help of MATLAB, establishing the 0-1 matrix between lines and stations helps to solve the multiple transfer route schemes. Finally, using the traditional Dijsktra algorithm helps to validate the path of choice. Comparison results have shown that using minimum transfer model, identification line will be at a lower cost. This essay provides a query of the standard algorithm. Given the urban public transport data, the corresponding query results will be the output.

The global ecological environment is facing great pressure. In recent years, China has continuously promoted the process of green development, and put forward the goal of carbon peak and carbon neutralization. Transportation industry is one of the important sectors of carbon emissions, and the measurement of carbon emissions is also a concern of the world. The turnover of ship transportation is the basis for the measurement of carbon emissions in the shipping industry. But, the measurement of carbon emissions from water transportation industry is not complete. There is a lack of statistics on the turnover of oceangoing ships sailing along the coast. This creates obstacles for China to accurately reduce carbon emissions. Therefore, it is very important and necessary to calculate the turnover of oceangoing ships sailing along the coast. This has also become the focus of this study. This paper constructs a route network model. Based on ship berthing data, the coastal transportation turnover of ocean-going ships is calculated. This paper selects five typical routes and three key areas as the research objects. According to the characteristics of navigation, the international container ship is calculated. By analyzing the key indicators such as the number of ships, the number of cargoes, the number of port of call, and the coastal navigation distance, the turnover of ships on each route in the year is calculated. Accordingly, in 2020, oceangoing ships turnover in China's coastal transport is 957 billion tons of kilometers, accounting for 9.4 % of China's waterway transport turnover.

In urban road systems, malformed intersections are one of the pain points. And their unreasonable signal timing is a major contributor to issues such as low intersection capacity and high safety risks. This paper uses the Webster model to investigate the relationship between intersection angle, driving path and stopping sight distance, considers the impact of road intersection angle on lost time and saturation flow, and proposes a signal timing optimization method for malformed intersections based on the change of road intersection angle. The article takes a malformed intersection of South Tai Bai Rd in Xi’an, Shaanxi Province, as an example, and gives a signal timing optimization scheme using Synchro, while VISSIM is adopted to verify the effect of the signal timing optimization scheme. The results show that compared with the conventional signal timing model, the overall average queue length of the intersection is reduced by 18.74%, the average vehicle delay is reduced by 1.82%, the number of stops is reduced by 22.93%, the level of service of intersection is improved from E to D, and the overall traffic operation efficiency is significantly improved by using the model developed in this paper. The research results are of great practical and guiding significance to alleviate congestion at malformed intersections and improve intersection traffic safety and efficiency.

In the existing train control system, the on-board DMI displays the current speed, target speed, distance, and other basic information of the train, but there is still some safety information not displayed, such as the train’s route information and the speed limit of the switch. The dispatcher handles the route according to the fixed block section length, which will reduce the operation efficiency for the train with low speed. If the temporary speed limit command is not confirmed and checked on the on-board equipment, once the wrong temporary speed limit command is received, it will endanger the train safety. The tracking interval of existing trains is realized by ATP. If ATP fails, it will cause train rear-end collisions. In this paper, 5G technology and Beidou positioning technology are used to realize the visual extension of the train route, route handling in variable route section, wireless check of the temporary speed limit, and parallel monitoring of train tracking interval, so as to improve the safety and efficiency of train operation.

Track irregularity is the basic input for the wheel-rail interaction of rail vehicles. Therefore, understanding of track irregulates is essential for the top-down design of vehicle system dynamics and track maintenance. Based on the method of Kalman filter, this paper derived the vehicle system dynamic model of a high-speed train and developed an adaptive Kalman filter. In the study, the dynamic responses of body and bogie system are taken as the observable quantities, which is further employed to estimate the vertical track irregularities based on the adaptive Kalman filter. The results show that the proposed method is capable of estimation of track irregulates by using limited dynamic response obtained from the body and bogie system. In addition, the estimated track irregulates show good correlation with the original track irregularities, which further implies that the proposed track irregularities reverse method can yield very high accuracy in the estimation of track irregularities.

To analyze influencing factors of rider injury severity in E-bike-motor vehicle collision accidents, we have analyzed 1,246 accidents in the China In-depth Accident Study (CIDAS) dataset using the Light Gradient Boosting Machine (LightGBM) model, which is used to further explore primary factors affecting the injury of riders. Experimental results show that severity of injury is highly correlated with traffic environment, characteristics of electric vehicles and riders. Meanwhile, we find that the throwing distance of riders has an obvious threshold effect on death, and accidents occurred outside urban areas are more likely to lead to death of riders. Finally, suggestions are made for the causes of accident injuries. This research is beneficial to the understanding of complex nonlinear relationships between accident injuries and influencing factors. The experimental results and analysis provide more guidelines to investigate injury prevention measures.

According to the key of the traffic characteristics signalized intersections in the port area and propose a design scheme of the left turn at the intersection. Analyzing traffic flow conflicts and studying research on phase sequence and phase optimization model, a method of using phase matrix to express phase sequence is proposed. The result shows that combined with contraflow left-turn lane, the new phase sequence and phase optimization scheme and timing scheme can effectively reduce the intersection delay.

In recent years, China's highway construction has developed rapidly with huge investment. However, the highway management is relatively extensive and there is a need to improve supervision and service in the fields of road planning, investment, construction and maintenance. Satellite images have the outstanding advantages of large coverage, authenticity and low cost, which can be used as the data basis of highway management. This paper analyzes and compares the available satellite image resources in highway management, and summarizes the typical application fields in highway management. At the same time, aiming at the difficulties in the application of satellite images in rural highway management, the algorithm mechanism of rural highway network extraction and line enhancement is proposed, which can significantly improve the application effect.

Online car-hailing and taxi, as two typical modes of non-public transportation in the urban passenger transport market, are showing an increasingly obvious competitive situation. In order to accurately understand the selection characteristics and preferences of online car-hailing and taxi users, this paper analyzes the results of the RP questionnaire based on SPSS analysis software. For the two travel modes, correlation analysis is carried out between user attributes, service evaluation and order attributes, and cross-analysis is carried out on user attributes and usage characteristics. Finally, compare the differences in user selection characteristics of the two travel modes. The analysis results show that users have obvious differences in characteristics and preferences under these two travel modes. For example, female users use more aggregation platforms, while male users gradually increase their use of aggregation platforms as they age. They prefer to choose taxis for short-distance travel, and online car-hailing for long-distance travel. The research results can provide valuable reference for the relevant government departments to formulate more reasonable traffic travel management policies.

In order to realize the accurate automatic detection of the potholes depth index of asphalt pavement by laser 3D technology, an iterative datum fitting algorithm is proposed, and on this basis, two judgment methods of the depth index are proposed, and algorithm is developed for automatic recognition. The precision laser point cloud data of road surface was obtained by HandySCAN3D handheld laser 3D scanner, and the validity and accuracy of datum selection and potholes depth calculation algorithm were verified by internal step standard potholes model. The results show that the repeatability of measurement results is less than 5%, and the average error of measurement is less than 3%. The algorithm is further used to detect the actual potholes and compared with the measured results. The error is is less than 3% which verifies the feasibility in practice.

Adaptive control algorithms can adjust the signal period in real time and have a high calculation rate. This paper uses the holographic traffic signal control system of multi-source data fusion to fuse the original traffic data obtained by a variety of sensors, adopts adaptive control algorithm and artificial intelligence conversion technology, combines the fused traffic data information with the OpenATC open source signal machine independently developed in China, and designs a signal control scheme that conforms to the current road network. In the sumo simulation environment, the comparison and verification were carried out in coordination with the traditional static two-way green wave, and the comparison results showed that the average length of the maximum queue at a single intersection decreased by 25.03%, and the average parking delay at a single intersection decreased by 61.51%. This method can effectively alleviate the occurrence of traffic congestion events in the road network and improve the efficiency of road network traffic.

With the acceleration of the port development process, the traffic problem of port area is becoming more and more obvious. In order to improve the traffic operation efficiency and environmental benefits of intersections, the intersection adjacent to the port and the port gate are approximately regarded as a system, and the signal timing optimization model is established by comprehensively considering the factors such as vehicle queue at the port gate, vehicle delay and capacity, emissions and so on. Combined with an example, the signal timing scheme is improved. The simulation evaluation is carried out by using VISSIM. The results show that the model in this paper can alleviate the queue problem at the port gate, reduce the vehicle delay, improve the capacity and alleviate the problem of pollutant emission, and the model has a good signal control effect.

In order to investigate the pricing strategy and revenue of shipping enterprises in the case of maritime shortage of containers, the study establishes a shipping decision-making model in the case of no shortage of containers and shortage of containers, gives the optimal decision-making of shipping enterprises, studies the impact of containers shortage on shipping enterprises, and explores the role of scalpers in the shipping chain. Through a numerical example, this study analyzes the revenue differences between scalpers providing missing container and carriers providing missing container. There are following three conclusions that can be drawn from this study. Firstly, the revenue of each enterprise in the shipping chain will be damaged under the shortage of containers and the negative impact on carriers is greater than that on freight forwarders. Secondly, the participation of scalpers will reduce the revenue of shipping enterprises. Finally, when the cost of additional containers provided by carriers is below a certain threshold, they have the willingness to actively participate in container resource allocation.

The accuracy of traffic flow prediction is significantly degraded by data anomalies and data noise. To solve this problem, a hybrid traffic flow prediction model based on iForest-VMD-GRU is proposed in this paper. Firstly, we detect the outlier anomalies in the original traffic speed sequence through iForest and use interpolation to complete the normal traffic speed sequence. Then, to reduce the interference of noisy data and improve the model prediction accuracy, we decompose the normal traffic speed sequence into basic trend components and multiple random fluctuation components through VMD. Finally, GRU is used to predict each subsequence, and the predicted values of each subsequence are combined into the final prediction results. The empirical analysis shows that the proposed model in this paper can significantly improve the prediction performance.

The goal of high-quality development of transportation has put forward higher requirements for the refined prediction of water transportation safety production situation, and the construction of the index system affecting the water transportation safety production situation is the basis for the realization of refined prediction. The gray correlation analysis method was used to systematically analyze the influencing factors of water transportation safety production situation in different waters. The results show that the influence of the number of ships and berths is the most prominent, and the influencing factors in different waters have large differences, among which the influence of port throughput and passenger traffic on the coastal water transportation safety production situation index is the largest. The number of ships and berths are the factors with the highest correlation to the safety production situation of inland water transportation, and the net weight of ships and the number of bad weather have a correlation coefficient of more than 0.8, which is an influencing factor that cannot be ignored.

Bulk transport has the highest requirements for navigation map service system among all vehicle transport. This paper designs and implements a navigation map service system for bulk transport, which provides simulated road survey, three-dimensional channel simulation and electronic fence and other functions for the transport of bulk goods. It meets the demand of navigation map service for bulk cargo transportation.

In view of the randomness of vehicle owner charging and the instability and fluctuation of wind power generation microgrid connected to the power grid, a multi-objective optimization model of electric vehicle (EV) charging and discharging in the microgrid connected to distribution network and its solution algorithm are proposed. The charge and discharge activity of EVs is modeled from the point of view of the power grid and EV users. The multi-objective optimization model is established to minimize the peak-valley difference of the original load curve and the charging cost of EV users, and the NSGA-Ⅱ algorithm is used to solve the problem. To verify the feasibility of the model, a region is selected to use the established model, then the Pareto-optimal front is obtained, and the final scheme is obtained based on the fuzzy logic theory. Different target weights and different V2G (Vehicle to Grid) responsiveness are simulated and analyzed, and the corresponding example results show that the proposed optimization strategy can better shave peak and fill valley of the distribution network load curve and bring economic benefits to users so that the power grid and users can achieve mutual benefit.

As a new kind of radar system, the research of bistatic SAR is becoming more and more popular. Unlike single-base radar resolution calculation, bistatic SAR has a new algorithm to calculate the resolution. The proper configuration of Spaceborne-Airborne bistatic SAR system has a great influence on the imaging results, so it is very important to set the configuration parameters of the Spaceborne-Airborne bistatic SAR system. This paper takes Spaceborne-Airborne Bistatic SAR as an example to analyze the effects of system parameters, such as transmitter out-of-receiver angle, incidence angle of transmitter, incidence angle of receiver, velocity and position vector of transmitter and receiver on target area imaging, providing theoretical support for subsequent system research.

The northwest region of China is severely cold. The ice and snow conditions have a great impact on the traffic operation efficiency, which will change the road friction coefficient, vehicle performance and signal control timing parameters. This leads to increased delays at intersections and reduced traffic capacity, and normal weather signal control timing is no longer applicable under icy and snowy road conditions. Therefore, people propose a multi-objective optimization scheme of information control timing, which comprehensively considers factors such as delay, passing capacity, and parking frequency to establish a model, and use genetic algorithm to solve it. The data analysis is carried out by taking the typical intersection in Urumqi as an example. The survey results show that the timing optimization technology using multi-objective information can solve the problem of congestion at the intersection of ice and snow roads, and has a better traffic signal regulation effect.

There are two typical issues in the smooth transition algorithm, which is commonly used for coordinated control of urban road traffic signals. Firstly, when selecting the transition adjustment strategy, the inherent relationship between the two transition adjustment strategies, extension and shortening, can be easily ignored. Only a single transition adjustment strategy can be chosen directly, and the strategy tends to be unsatisfying. Secondly, deficiencies exist when understanding coordinated and non-coordinated phase requirements, and the distribution can be uneven when the green signal ratio is allocated in the transition adjustment scheme. To address these issues, this study explores the internal relationship between the two transition adjustment strategies, namely, extension and shortening, and defines the periodic correlation adjustment amount. Comparing and analyzing the impact of the amount of adjustment in the two strategies on the total transition period and duration, they account for 5%, 15%, and 25% of the cycle, respectively. It reveals that the adjustment strategy produced under a single rule cannot meet the basic needs of the shorter total transition adjustment time and lacks the general rule of response mechanism to the background cycle change trend. Targeting embedded traffic signal control devices, we further propose to optimize the speed of adjustment and small fluctuation of the scheme as the goal. This model includes two levels of decision indicators, TS and Dev, which characterize the adjustment speed and the deviation of median value in the representation cycle. After adjusting the strategy and parameters following the model output, we fully consider the difference in demand for access to the experience and release efficiency between the coordinated and uncoordinated phases. Overall, the complete construction of a coordinated transition adjustment process consists of three parts: identification of transition adjustment, the establishment of a decision model and implementation of transition adjustment.

Based on the meteorological observation data of 70 reference meteorological observatories in Jiangsu Province, using the method of meteorological inclination and zoning, the law of change and spatial distribution of extreme temperature in our province in the past 40 years are analyzed. Based on the distribution of extreme high temperature and extreme low temperature, combined with the temperature data of meteorological reference stations in recent 10 years, the meteorological distribution in Jiangsu Province was preliminarily divided into regions. At the same time, the design of asphalt pavement is further calculated. Based on the reference equivalent temperature, combined with the calculation of the permanent deformation of the typical road structure in our province, it is proposed that the road temperature design parameters should be calculated based on the temperature parameters of more than 70 meteorological reference stations in the province, or perform structural verification based on the benchmark equivalent temperature of the three regions in the province.

In the present day, the traditional modes of public transport are challenging to provide an economical and fast solution, so the need for a cheaper and quicker implementation of a new public transport system is recognized by more and more countries. Bus Rapid Transit (BRT) systems are becoming the most popular public transport option with medium carrying capacity. This system not only reduces the investment cost in public transportation but also achieves the operation effect close to that of rail transit. It uses modern public transport technology to cooperate with the operation and management of intelligent transportation so that the traditional public transport system can basically reach the service level of rail transit. In this study, the mapping methods of BRT system Road (graphically correct bus maps and schematic bus maps) are introduced and analyzed to improve the satisfaction of the BRT system in practical application. In addition, the applicable conditions of the two road-mapping methods and the principles needing attention in the drawing are also analyzed. As for the BRT system structure, this paper introduces a new BRT system model ("BRT + flexible line" mode), which is used to improve the speed of the BRT system. Firstly, the information of the BRT system is extracted from Xiamen, Guangzhou and Mexico, and the route map and design mode of BRT systems are analyzed and drawn by using ArcMap and Inkscape software. The relationship between line mapping and BRT system is summarized. Finally, the conditions and shortcomings of the experimental results are discussed, and it is pointed out that local conditions should be considered to simplify the drawing of geographically correct bus maps in the BRT system. This study can be widely used in the initial construction of the BRT system and the construction mode of air-light rail, and also can be applied to the drawing of the BRT system route map. It is hoped that this study can provide a starting point and useful experience for researchers in this field.

In order to ensure the surface quality of cold rolling products, the scale layer on the surface of hot rolling strip should be cleaned. The traditional descaling mode is pickling, which has the problem of waste acid discharge and environment pollution. Shot blasting impact descaling is an advanced and green descaling technology. However, the mechanism and law of shot blasting and descaling are not clear yet. In order to further study the damage law of scale layer under projectile impact, a finite element model was established based on the birth-death element method (BDEM) and simulation calculation was carried out. The results show that the scale layer elements are continually deleted after reaching the failure threshold with the help of BDEM decision rules. Descaling process is accurately simulated. With the increase of projectile impact velocity, the descaling area increases, but the growth rate slows down when the velocity exceeds 60 m/s. The reasonable impact velocity should be selected according to the steel type and the property of scale layer.

High pressure common rail injection technology points out the direction for the development of diesel engine electronic control technology, and can meet the requirements of emission regulations in more than four countries. It has been recognized as the most potential fuel injection system, with a huge market and broad prospects. Through the digital simulation calculation of the main components of the fuel injection system of common rail diesel engine, this paper can reduce the conflict between design modification times and matching problems, and improve the efficiency of mechanism design and performance matching.

In the process of electricity spot market construction in China, the regional demand-side participation difference has led to the diversification of the electricity price mechanism. The market settlement balance has become an important issue of market development. Based on comparing the settlement methods of electric energy market firstly, this paper enumerates two kinds of congestion charge calculation methods; then it researches the impact on unified settlement point price mechanism on the congestion charges settlement of different spot markets, as well as the coupling with the dual-track market structure balance, and puts forward the multi-scenario settlement balance methods of the zoning locational marginal price mode. Finally, with a numerical example, it verifies and analyses the impact of demand-side electricity price mechanism on market settlement charges and validity of the proposed the zoning settlement balance method, so as to provide an effective reference for the market mechanism design and market entities’ transaction risk management in the future.

The influence of inclined shaft on thrust bearing was analyzed. The physical model was firstly built. The flow field of the oil film of thrust bearing was simulated by using the fluid dynamics simulation software based on the principle of fluid dynamics. What is more, the characteristics of the flow field were obtained. The influence of tilt angle on the distribution of oil film pressure field and temperature field is investigated. Then the calculated results are shown by diagrams. The results are analyzed in detail. The results demonstrate that axis inclination will cause the uneven distribution of temperature field and pressure field, and increase the pressure and temperature of the oil film at some pads. The heterogeneity of the distribution increases when the tilt angle increases

Most of the transmission wires in the traction network are laid outdoors. The influence of the geographical location and the surrounding meteorological environment on the carrying capacity of the transmission wires cannot be ignored. This paper focuses on the analysis of the influence of geographical and climatic factors on the current load of transmission wires, and puts forward the method of dividing the wind speed interval according to the calculation results of the current load.

The author of this article refers to its collection, storage, processing, use, provision, transaction, and disclosure activities as data activities. Data transaction refers to the behavior of data owners to conduct free transactions under market transaction rules in accordance with the law, and is also listed as one of the economic activities of data. The series of behaviors in data transactions are inseparable from the nature of data pricing—a valuation behavior relationship is inseparable, and the two complement each other. The purpose of valuation is for transactions. Valuation is indispensable in transactions.

Based on the analysis of ship navigation big data, it reveals the drawbacks of the ship route management mode based on the shortest path planning, and deeply combines the ship energy efficiency management and route management to find real-time dynamic energy-saving routes for sailing ships. The system can consider the energy efficiency of ships in dynamic sea environment, build a sea grid environment with fuel consumption model, and execute an improved ant colony algorithm to plan energy-saving trajectories for ships, so as to achieve energy saving and emission reduction. The system is able to plan an energy-efficient trajectory for a ship, thus achieving energy saving and emission reduction.

The number of regional airports in China is large and widely distributed. The construction of regional airports has received attention, but there is a lack of research to explore their classification. Taking 182 airports with passenger throughput less than three million (inclusive) nationwide in 2019 as the research object, six indicators within and outside the civil aviation industry were statistically investigated. By using factor analysis, the values of the categories were determined between three, four, five and the corresponding components were extracted, and the clustering method was used to analyze all samples by clustering three, clustering four, and clustering five. The results were calculated with the contour coefficients of 0.90, 0.96, and 0.92, respectively, and it was determined that the clustering effect of clustering four categories was better. The national regional airports were divided into four categories: the extracted components corresponding to the first category of airports were total tourism income, the extracted components corresponding to the second category of airports were urban population and gross regional product, the extracted components corresponding to the third category of airports were takeoff and landing movements, and the extracted components corresponding to the fourth category of airports were airport passenger throughput and airport cargo and mail throughput. The extraction components and geographical location of the four types of airports are studied, and the characteristics of each type of airports are summarized, so as to pave the way for future research on the planning and overall layout of regional airports.

Person re-identification (Re-ID) shows huge application scenarios in video retrieval scenarios. However, there are many challenges that hinder the development of person Re-ID technology such as variable recognition background, pedestrian misalignment and occlusion. Attention mechanism is proposed to strengthen the ability of the basic network in extracting discriminative features, but it ignores some useful detailed information in the original features. In order to solve this problem, we propose a Source-Attention Feature Fusion network (SAFF-Net) to extract pedestrian representations combining attentional features and original features. Specifically, SAFF-Net first extracts the saliency discriminative pedestrian features of pedestrians by embedding the channel attention module in the backbone network. And then by cross-fusing saliency discriminatory features and original features, these fused features can direct the model to focus on both saliency discriminatory features and original features, thus increasing the completeness and richness of pedestrian representations. Experiments show that our method is competitive with other state-of-the-art person Re-ID methods.

Aiming at the problems of long time-consuming and low accuracy of UAV route planning from start to end in the current algorithm, a UAV route planning algorithm based on conflict resolution mechanism is proposed. Determine the constraints and avoidance conditions of UAV turning angle, calculate the UAV navigation node distance, introduce the conflict resolution mechanism, plan the UAV multi route trajectory, smooth the UAV route, and realize the UAV route planning. The experimental results show that when the proposed algorithm is applied to the actual UAV route planning, it can shorten the UAV flight time, ensure the equal time consumption of each flight, and improve the UAV flight efficiency and route planning accuracy on the premise of ensuring that the UAV is not affected by each threat point.

The performance evaluation of plateau ecological transportation and the judgment of its obstacle factors are the important foundation for the sustainable development of plateau ecological transportation. This paper uses the DPSIR model to construct the plateau ecological transportation evaluation system, uses the weighted TOPSIS model and the obstacle degree model, and evaluates the development performance level and obstacle factors of its ecological transportation based on the ecological environment data and traffic development statistics of the Tibet Autonomous Region from 2005 to 2015. The results show that the comprehensive closeness index has gradually increased from 0.0636 in 2005 to 0.8997 in 2015, a steady increase of 7.6%. The impact subsystem has the greatest impact on the development of the overall plateau ecological transportation evaluation system, reveals the short-board influencing factors of the sustainable development of plateau ecological transportation, and provides references for the improvement of the overall plateau ecological transportation system and related decision-making.

Based on the measured data of wheel diameter of Suzhou Metro Line 2, the correlation between wheel diameter and train operation mileage is analyzed. Fistly, in order to explain the force relationship between wheel and rail, the method of multi-body dynamics has been used. After that, to predict the residual life of wheels, using genetic algorithm optimized neural network and data fitting methods. Finally, the fitting formula can be used to predict the useful life of wheel. It is of great significance to prolong the service life of wheels and reduce the operating cost of vehicles.

Predicting the wear state of the wheels and predicting the possible problems of the wheels in advance can help guide and optimize the maintenance and repair work of the vehicles, and reduce the economic losses caused by the untimely vehicle maintenance scheduling. In this paper, the long short-term memory (LSTM) recurrent network is used as the prediction model. In order to improve the prediction accuracy of the network model, the Ensemble Empirical Mode Decomposition (EEMD) algorithm is introduced to stabilize the non-stationary wear sequence and improve the training effect neural network. Firstly, the non-stationary original wheel diameter sequence is decomposed into multiple stationary sub-sequences by the EEMD algorithm, and then the training and prediction of the LSTM model are completed separately based on each component. The experimental results show that after EEMD processing, the prediction effect of tread wear has been improved, which verifies the improvement effect of EEMD processing on the prediction accuracy of neural network.

With the continuous expansion of the operation scale of urban rail transit, the urban rail transit shows an increase in the ratio of transfer passenger flow, the superposition of passenger flow between lines is apparent, and the changes in passenger demand are complex, making it difficult for operation managers to grasp the variation of passenger flow accurately. Under the current passenger flow management and operation conditions, accurate short-time passenger flow forecast data could help improve the management and operation level of urban rail transit and passenger travel experience. This paper first analyzes the demand for short-time passenger flow forecast of urban rail transit and the short-time passenger flow forecast process. Secondly, because of the nonlinear characteristics of passenger flow in different periods of a single day, and based on analyzing the historical passenger flow changes, the paper proposes a short-time passenger flow forecast method based on fractal interpolation theory. The passenger flow curve calculated by this method is more in line with the actual situation. Finally, the accurate passenger flow data of several stations in a city in western China is used for verification, and the forecast accuracy is about 96.63%, which proves the feasibility and accuracy of the method.

Traditional traffic planning only considers the single objective which is not reasonable. This paper establishes a stochastic multi-objective network design model with the concept of Pareto optimal. The genetic algorithm is used to solve the model, and then gives an example with Nguyen-Dupuis network. The result shows that different objectives have substitution relations in multi-objective model. The model can provide scientific, systematic and effective decision-making scheme and decision data for the decision-maker.

Expressway plays a significant role in promoting social and economic development, while traffic safety matters are following. In actual expressway scenario, events such as occupying-road constructions and traffic accidents will narrow carriageways and obviously decrease the traffic capacity. Therefore, it is particularly important to improve the effectiveness of security management in bottleneck areas. To describe the driving features in bottleneck areas, this paper proposes a safety evaluation method for expressway bottleneck areas based on the traffic Spatio-temporal proximity index. In the proposed method, the time to collision (TTC) and post encroachment time (PET) indexes are applied to describe the proximity characteristic in both time and space dimensions and then calculate the indicators of the bottleneck area. Then, the fuzzy C-means (FCM) algorithm is used for classifying the risk levels so that the thresholds of TTC and PET can be obtained and the risk factor of bottleneck area is further calculated, due to which the safety level of the expressway bottleneck area is comprehensively evaluated. Finally, the proposed method is simulated and the performance is analyzed using VISSIM. Simulation results show that the safety level is in accordance with its actual area characteristics and the proposed method can surely provide reliable theory support for the expressway traffic safety management.

To improve the comfort and safety of ships during navigation, using intelligent algorithms to optimize the design of ship propulsion shafting and improving the transmission efficiency of ship propulsion shafting is an important research direction for ship structure optimization design. By comparing and analyzing the widely used intelligent algorithms, the most suitable intelligent optimization algorithm for the transmission efficiency of ship propulsion shafting is selected from the perspective of ship shafting dynamics and tribology. Taking a ship comprehensive performance test platform as the research object, the multi-objective optimization of the power transmission of the propulsion shafting is carried out. The research shows that the optimization algorithm can effectively improve the shafting transmission efficiency, and has certain feasibility.

The Yangtze River is the busiest river in the world. It plays a vital role in coastal economic development. With the increasingly busy transportation of the Yangtze River in recent years, the freight volume of the Three Gorges lock increases gradually. A large number of ships queue up at the upstream and downstream of the Three Gorges to pass the lock. It increase transport costs and security risks. The average waiting time for ships was about 150 hours in 2018. The layout of ships passing through the Three Gorges ship lock needs to be further optimized. In this paper, the ship lock arrangement model based on multi-objective decision is constructed to further improve the transportation efficiency of related lock ships. We hope to further alleviate the Three Gorges ship congestion problem. After expert consultation, this paper selects two objectives : the best economic benefit of lock and the maximum weight of ship. In other words, the model further balances the maximum area utilization and the maximum ship weight. By adding constraints and data processing, the model can be applied to solve practical problems. This model presented in this paper can be applied to the optimal scheduling of ships passing through the Three Gorges Ship lock and other ship locks. Finally, this paper illustrates the feasibility of the model through a case study. The best one was selected from the five arrangements of six ships. The case study shows that the model can optimize ship layout.

In view of the limitation that the static risk assessment is difficult to describe the dynamic characteristics of risk factors, this paper proposes a dynamic risk assessment method for navigation safety in exploration waters based on dynamic Bayesian network. Firstly, given the uniqueness of exploration operation, the navigation risk index system of exploration waters is established; And then the prior probability of the node is determined by using the improved D-S evidence theory, calculating the weight of the node by the improved fuzzy analytic hierarchy process and entropy weight method, and the conditional probability distribution of the intermediate node is calculated by the weighted distance formula, parameters of the model can be obtained; Then the navigation risk assessment model based on dynamic Bayesian network dynamically predicts the probability of maritime navigation risk accidents; Finally, sensitivity analysis is used to identify the key risk factors of accidents. The research results show that human factor, navigation environmental factor and management factor are determined as the key risk factors. The navigation risk is large during the transition period from preliminary exploration to detailed exploration, which is in good agreement with the actual evaluation of experts and the statistical law of historical data, indicating that the model can better predict the dynamic navigation risk level of construction waters.

Most of the fixed traffic detectors on urban roads are mainly based on one type of detector layout. For a specific area, the detection accuracy and layout cost of the detector layout in this way cannot meet the requirements of this road section. Therefore, according to the NSGA-II multi-objective algorithm rule, to accurately collect urban road traffic flow information and the lowest cost of coordinated deployment of traffic flow detectors, a mathematical model based on the accuracy of traffic flow detection and the lowest deployment cost is created. The type and quantity of λ are variables, and the NSGA-II multi-objective algorithm is used to obtain the type and an optimal number of detectors for co-optimization of detectors in a specific area. Compared with the traffic flow detection accuracy of a single detector in a specific area and the deployment cost that meets the detection conditions, the coordinated deployment and collaborative detection of multiple detectors not only significantly improves the traffic flow detection accuracy in this area, but also reduces the deployment cost.

With the frequent disasters in recent years, the importance of emergency logistics has gradually come to the fore. The distribution optimization of emergency logistics has always been an important part of emergency logistics, and a reasonable distribution path can not only save the economy but also protect the lives and properties of the affected people in a timely manner, which has always been of great concern to scholars. The article considers the priority distribution of emergency supplies and the different priorities of the affected areas in the context of the actual situation when an emergency situation occurs. Also considering the problem of demand uncertainty and disaster area priority due to unexpected events in the disaster area, the grey theory model is used to predict the uncertain demand and the hierarchical analysis method is used to determine the disaster area priority. The emergency material distribution model considering priority and demand uncertainty is constructed, and the genetic algorithm is designed to solve it and obtain the optimal distribution path, which verifies the effectiveness of the model and algorithm.

The reform involving the replacement of business tax with value-added tax (VAT) is a significant finance and taxation reform in China, which will significantly affect the transportation industry. It is very important to assess the transportation enterprise tax burden during the reform, which will contribute to improving enterprise management and government policies, and successfully executing the replacement of the business tax with a VAT in the transportation industry. In this paper, according to the highway enterprise characteristics (their construction and operation), the factors affecting the total tax burden are studied, and a tax burden calculation model is established based on multiple factors and the whole life cycle. Finally, a highway is used as a case study to demonstrate the application of the presented model. The results reveal the concrete tax burden and the rationale therefor, allowing suggestions for government departments and enterprises to be proposed.

In this paper, four typical driving behaviors with strong risk of cognitive distraction were obtained through questionnaire survey, and simulated driving experiments of normal driving and four typical driving behavior sub-tasks were carried out. Eight characteristic indicators are selected from the characteristic values of vehicle operation information, and a long-short-term memory neural network model (LSTM) is established to discriminate driving distraction, which is compared with SVM model. The results show that the LSTM model can accurately identify the cognitive distraction state of the driver.

With the growth of waterway transportation volume and port cargo throughput, the phenomenon of detention often occurs in many ports. For the sake of the utilization efficiency of channel and berth, this paper modified the model of ship entering and leaving port order and berth allocation scheduling of one-way channel and considered the factor of safety first. In the planning period, a mixed integer programming model was established to minimize the sum of all ships waiting cost and the berth deviation cost. In view of the situation that large ships need to enter and leave the port by tide, this study put forward the constraints of sailing time based on the continuity of the tide, so that could improve the safety of ships entering and leaving the port. The corresponding genetic algorithm (GA) was designed to solve the model, and verified the effectiveness of the model and algorithm.

In this paper, a heuristic FIFO algorithm combined with decision tree algorithm is proposed for the problem of urban rail transit crew planning. First, when cutting the crew carriage working diagram, we select the minimum fragment cutting method based on the crew lounge to ensure that the cutting method does not affect the decision result. After that, the FIFO algorithm is used to solve the problem, combined with the decision tree algorithm to correct the defects generated by the FIFO, heuristically search for the locally optimal solution. We use the Depth First Search in the search process to reduce the amount of calculation. When the termination condition of the search algorithm is satisfied, if no feasible solution for the connection of the crew shift is found, the target value will be reduced by one to restart. The above process is repeated until a feasible solution is found. Computational experiments based on four operating diagram data of a subway line show that compared with the traditional manual schedule compilation of operating companies, this algorithm can obtain better results. In the future, in the face of more complex urban rail transit lines, this method can show more advantages.

Accurate traffic trip prediction is an important guarantee for achieving long-term development of intelligent transportation. To cope with the complex and variable factors of elderly people's public transport travel decision-making behavior as well as to improve elderly people's travel, this paper proposes a deep learning-based convolutional neural network for predicting urban elderly people's public transport travel. Taking the plateau city of Lhasa as an example, the data from October 2018-December 2019 of elderly people's bus passes are selected for deep convolutional neural network and regression model modelling respectively, and the results obtained are compared through the model for prediction experiments on January 2020 data. The experimental results show that the mean absolute error (MAE) as well as the root mean square error (RMSE) are reduced by 0.112 and 0.156 compared with the traditional regression prediction model, further indicating that the model has higher prediction accuracy, and is reliable and practical in predicting elderly people's public transport trips.

As an important hub port along the southeast coast of China, Xiamen Port provides strong support for the development of regional trade, and the sea-rail intermodal transport has strong potential in port consolidation and hinterland expansion. This paper uses the grey GM (1, 1) model and Markov model to build a prediction model for the sea-rail intermodal throughput of Xiamen port, and conducts statistical analysis on the sea-rail intermodal throughput data of Xiamen port from 2014 to 2021. The results show that the average relative error of the improved model is reduced from 15.66% to 6.25%, which greatly improves the accuracy of the improved model and increases the credibility of the model of sea-rail intermodal throughput of Xiamen Port. This paper predicts the development trend of the sea-rail intermodal throughput of Xiamen port in the next three years, providing a certain basis for the construction of the sea-rail intermodal transport market in Xiamen.

In order to reasonably evaluate the operation efficiency of shipping enterprises and improve the ability of enterprises to deal with operation risks, the evaluation system of operation efficiency of shipping enterprises is established by analyzing the influencing factors of operation efficiency of shipping enterprises. The Three-stage DEA model is used to analyze the operation status of 10 shipping enterprises from 2011 to 2020, and calculate and evaluate from the aspects of comprehensive technical efficiency (CRS), pure technical efficiency (VRS) and scale efficiency (SE). The results show that the proposed evaluation model can effectively analyze the operating efficiency of shipping enterprises, and the suggestions and measures based on the evaluation results can help enterprises adapt to the high-risk market environment.

This paper proposes and designs a risk early warning perception system for safety production by researching emerging technologies such as the IoT, artificial intelligence, big data, mobile Internet, and data visualization. The system uses OPC, Modbus, ODBC and other protocols as the data access protocol to realize the data access and storage of current, voltage, thermocouple, pulse signal, Ethernet, RS485/232/422. The system realizes real-time collection of fire alarm information and equipment operating status, multi-point concurrent monitoring of water pressure and liquid level in the fire-fighting water supply pipe network, real-time monitoring of residual current and temperature changes in the circuit, and real-time monitoring of harmful gases. The system improves the park's risk prevention and control ability and risk emergency response ability in an all-round and three-dimensional way.

With the development of shipping industry, vessels generate huge amount of vessel trajectory data in shipping production activities, which brings huge pressure to the storage and analysis of data. In order to improve the compression efficiency of a large amount of vessel trajectory data, a MapReduce-based vessel trajectory compression algorithm is proposed. The algorithm uses a twice-divided method to pre-process the vessel trajectory, dividing the original trajectory into several sub-trajectory segments. Based on the classical trajectory data compression algorithm, the algorithm introduces the MapReduce parallelization processing model and the processing idea of local processing combined with global optimization to compress each trajectory segment. In Map stage, the online compression algorithm is used to get the local optimal solution of the compressed trajectory, and in Reduce stage, the batched compression algorithm is used to globally optimize the merged compressed trajectory and get the final compressed trajectory. The experimental results show that the MapReduce-based vessel trajectory compression algorithm can reduce the impact caused by data skew and significantly improve the compression efficiency of vessel trajectory data. And for the compression of large-scale vessel trajectory data, the compression algorithm has obvious advantages over the traditional centralized trajectory compression algorithm.