This paper presents a theodolite-shaped coarse pointing mechanism system designed for the laser communication terminal of the low-orbit network constellation. The design scheme adopts angular contact ball bearings based on oil lubrication as the main load-bearing structure, and the volatilization of lubricating oil during the working life is analyzed and calculated. According to the margin requirement of the driving motor, the load torques of the coarse pointing mechanism are decomposed and investigated. Finally, the finite element analysis in the locked state is carried out. The analysis results show that the mechanism scheme has good feasibility.
Space telescopes are widely used nowadays with the development of space optics and manufacture technologies. Large aperture of telescope means better resolution and observation. However, due to the carrying capacity and outline dimension of rocket, the aperture of telescope cannot be too large. In order to get the large telescope, more and more scientists and engineers are coming to a new idea that assembling the large space telescope on orbit. First of all, the paper makes an introduction about the concepts and types of on-orbit assembly for telescope. Then paper presents some projects which are being conducted and takes one project as an example to introduce specific implementation methods of on-orbit assembly. What’s more, high precision robots are needed in this process. Therefore, paper also introduces technologies about the robots for space assembly. At last, the paper summarizes the features and technical difficulties in on-orbit assembly of large space telescope. Furthermore, the paper points out the development directions about on-orbit assembly telescope in the future, which can give some help or guidance to engineers.
An optimal design method for lateral support structure of space telescope based on topology optimization theory and substructure method is presented in this paper. Introduced how to simplify the finite element model by substructure method in the process of analysis. Topology optimization is performed on the reduced model. Based on the variable density method (SIMP method), a mathematical model of continuum structure topology optimization is created to achieve efficient use of materials. Design a new type of mirror support structure. Consider the shape of the mirror which under axial gravity, radial gravity and temperature load conditions. The fundamental frequency of the mirror and the displacement of the rigid body are constrained, and the manufacturability of the topological results are also considered. The static and modal analysis of the structure using finite element method shows that the basic frequency and the shape precision of the mirror can meet the design requirements (the fundamental frequency f >120Hz, the surface accuracy is better than λ/60 RMS, λ/10 PV). This shows the feasibility of the method proposed in this paper in the design.
This paper mainly introduces the motion analysis and the stress of some components of the full-disc vector magnetograph (FMG). As the connecting part of the FMG and the satellite platform, its main function is to adjust the optical axis of the FMG so that its imaging of the sun remains in the center of the CCD, thus achieving pitch and yaw of the optical axis. The maximum adjusting range is ±12′ and the regulation precision is ±5′′. The kinematic support is used to connect the optical box and the satellite platform. The two Monopods are respectively mounted on the two YZ planes of the optical cabin. The Bipod is mounted on the XZ plane of the optical capsule, which can adjust the pitch and yaw of the optical capsule. The movement of the Bipod is mainly powered by two motors. This paper simulates the force condition of the motor's screw sleeve to calculate the parameters of the motor. This article simulates the upward, downward, leftward and rightward movements of the pitch and yaw motions of the FMG's on-orbit pointing adjustment mechanism. Compared with the results of MATLAB theoretical calculations, the maximum error of the simulation results is 0.7969mm, and the minimum error is 0.0212mm, which basically accords with the ideal sports condition.
A novel locking mechanism for future space mirrors assembly is presented. Using this locking mechanism, future primary mirror segments can be autonomously locked and unlocked. This compact design adopts passive locking mode, which improves the on-orbit autonomous assembly performance. In this paper, first, the design details and operation principle are addressed. Then, the failure conditions are discussed. By the external driving force, the static structural analysis and dynamic analysis are implemented to validate the design scheme. The final results show that the proposed locking mechanism avoids significant failure conditions and is considerably power efficient.
A topological optimization design for the lightweight technology of supporting plate of the primary mirror is presented in this paper. The supporting plate of the primary mirror is topologically optimized under the condition of determined shape, loads and environment. And the optimal structure is obtained. The diameter of the primary mirror in this paper is 450mm, and the material is SiC1 . It is better to select SiC/Al as the supporting material. Six points of axial relative displacement can be used as constraints in optimization2 . Establishing the supporting plate model and setting up the model parameters. After analyzing the force of the main mirror on the supporting plate, the model is applied with force and constraints. Modal analysis and static analysis of supporting plates are calculated. The continuum structure topological optimization mathematical model is created with the variable-density method. The maximum deformation of the surface of supporting plate under the gravity of the mirror and the first model frequency are assigned to response variable, and the entire volume of supporting structure is converted to object function. The structures before and after optimization are analyzed using the finite element method. Results show that the optimized fundamental frequency increases 29.85Hz and has a less displacement compared with the traditional structure.
A conceptual lightweight rectangular mirror is designed based on the theory of topology optimization and the specific structure size is determined through sensitivity analysis and size optimization in this paper. Under the load condition of gravity along the optical axis, compared with the mirrors designed by traditional method using finite element analysis method, the performance of the topology optimization reflectors supported by peripheral six points are superior in lightweight ratio, structure stiffness and the reflective surface accuracy. This suggests that the lightweight method in this paper is effective and has potential value for the design of rectangular reflector.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.