KEYWORDS: Inspection, Image segmentation, Sensors, Cameras, 3D modeling, Image processing, 3D image processing, Oxygen, Mobile robots, Fluctuations and noise
This paper deals with an automated preflight aircraft inspection using a pan-tilt-zoom camera mounted on a mobile robot moving autonomously around the aircraft. The general topic is image processing framework for detection and exterior inspection of different types of items, such as closed or unlatched door, mechanical defect on the engine, the integrity of the empennage, or damage caused by impacts or cracks. The detection step allows to focus on the regions of interest and point the camera toward the item to be checked. It is based on the detection of regular shapes, such as rounded corner rectangles, circles, and ellipses. The inspection task relies on clues, such as uniformity of isolated image regions, convexity of segmented shapes, and periodicity of the image intensity signal. The approach is applied to the inspection of four items of Airbus A320: oxygen bay handle, air-inlet vent, static ports, and fan blades. The results are promising and demonstrate the feasibility of an automated exterior inspection.
This paper deals with the inspection of an airplane using a Pan-Tilt-Zoom camera mounted on a mobile robot moving around the airplane. We present image processing methods for detection and inspection of four different types of items on the airplane exterior. Our detection approach is focused on the regular shapes such as rounded corner rectangles and ellipses, while inspection relies on clues such as uniformity of isolated image regions, convexity of segmented shapes and periodicity of the image intensity signal. The initial results are promising and demonstrate the feasibility of the envisioned robotic system.
In a context of quantitative thermography, the major problem in determining the true temperature of an object
is the knowledge of its emissivity. This problem is very complicated, above all when its value changes during
the measurement. This article deals with a new radiative method for measuring true temperature fields with an
on-line determination of emissivity. This method, called thermoreflectometry, consists in the indirect emissivity
measurement by a reflectometry method in addition to the radiance temperature measurement. It assumes that
the shapes of bidirectional reflectivity distribution is homothetic for two wavelengths. This assumption is much
less restrictive than the gray body one (emissivity equal for two wavelengths). Finally, those two measurements
and the assumption are fused for determining the true temperature field and the diffusion factor field, a key
parameter of the method. This parameter provides information on the surface properties (diffuse or specular)
ans it is assumed to be independent of the wavelength. The theoretical basis of thermoreflectometry method are
explained and a precise description of the apparatus is given. Measurements on instrumented samples, heated
at a temperature of 350°C and with non uniform emissivity, are in broad agreement with the theory and show a
high accuracy of the method, in reference to thermocouples measurements. The main assumption of the method
is also verified by additional measurements of the bidirectional reflectivity distribution function (BRDF). These
results demonstrate the relevance of this method, based on a simple embedded sensor, for measuring the true
temperature field on samples with non-uniform and unknown emissivity.
This paper presents a thermal measurement system based on a Silicon image sensor camera operating in the Near Infrared spectral band (0.7-1.1 μm). The goal of the study is to develop a low-cost imaging system which provides an accurate measurement of temperature.
A radiometric model is proposed to characterize the camera response by using physical parameters considering the specific spectral band used. After a calibration procedure of the model, measurements of black body temperatures ranging from 300 to 1000°C has been performed. The Noise Equivalent Temperature Difference (NETD) is lower than ± 0.18°C at a black body temperature of 600°C. Accurate measurements are provided over the whole
temperature range by introducing an automatic exposure time control. The exposure time is adjusted for each frame along the evolution of temperature in order to optimize the temperature sensitivity and the signal-to-noise ratio. The paper also describes the conversion process of the apparent black body temperature to the real temperature of the observed object using its emissivity and surface geometry. The overall method is depicted and the influence of each parameter is analyzed by computing the resulting temperature
uncertainty. Finally, preliminary experimental results are presented for monitoring real temperature of moulds in a Super Forming Process (SPF).
KEYWORDS: Cameras, Sensors, Detection and tracking algorithms, Flame detectors, Temperature metrology, Black bodies, Video, Near infrared, Optical engineering, Target detection
We introduce a new approach to aircraft cargo compartment surveillance. The originality of the approach is in the use of a single sensor type, a CCD camera, to detect fire events and freight movement in aircraft cargo holds (multiphenomenom/monosensor approach). The CCD camera evaluation and the radiometric and geometric models are provided in (Sentenac et al., 2002). We go on to discuss the image analysis algorithms used in the detection of fire signatures (hot spots, flame, and smoke) and load displacement. For each phenomenon, the discriminant parameters are established and the algorithm is explained. The crucial factor is the validation procedure according to aeronautical standards. The experimental trials were carried out in a test chamber providing the fire and smoke test facilities [TF1 to TF6 following EN 54 (Afnor, 1997) requirements].
KEYWORDS: Sensors, Modulation transfer functions, Cameras, Near infrared, Charge-coupled devices, Calibration, Temperature metrology, 3D modeling, Video, Black bodies
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.