The Infrared Image Processing Research Of The Infrared Fault Diagnosis System Of The TCAS Circuit Board

Civil airplane aviation electronic system has now turned into the total digital system development stage. The new generation of civil aircraft airborne electronic system adopts the total digital aviation electronic system of the integrated modular aviation electronic system(IMA) structure. The integrated density of the electronic equipment is increasing, which increases the complexity and difficulty of the fault testing of the circuit board. The situation leads to that the original maintenance means and experience can't meet the modern aircraft electronic equipment's maintenance requirements.Traffic alert and collision avoidance system(TCAS) is one of the very important electronic equipments in the airplane; its performance plays a very important role in the safety of the airplane. With our infrared thermal imaging technology and signal loading technology and the application of intelligent fault information processing method of the knowledge base, the task group develops the TCAS circuit board infrared fault diagnosis system.The paper introduces the detection principle of the infrared imaging technology at first,making the research of the feasibility of the infrared diagnostic circuit board; The composition principle and processing of the infrared fault diagnosis system of the TCAS circuit board are explained and the diagnostic system development and the problems which should be paid attention is analyzed.In view of temperature rise of the working status of the TCAS circuit board is small, the thermal image of the circuit board is dark, the light radius is not enough, and the components contour are not clear, low contrast, and its corresponding gray image information range is narrow. According to the requirement of the subject project, the paper does the main research for the infrared image processing algorithms of TCAS circuit board infrared diagnostic system. On the comparison of the several classic image enhancement algorithms, the combinative algorithm of the new type of histogram equalization algorithm and the enhancement algorithm of the high-pass filter is put forward, making the image enhancement processing in the infrared image of the TCAS circuit board. The MATLAB simulation experiment results show that the algorithm can enhance the brightness and reduce the noise of the image and the visual effect is good.Image segmentation prepares for the feature extraction and the target recognition. It is an important link of the image processing. The paper analyzes the several classical algorithms of the image segmentation. Because the edge detection segmentation algorithm only shows the edge profile of the target, after processing, the lines are so many and discontinuous; And thethreshold segmentation algorithms rarely consider the spatial location and boundary information of the target, ignoring the edge details between targets; The paper puts forward a new infrared image segmentation algorithm. The algorithm uses the canny operator realizing the edge detection, at the same time, based on iterative self-organizing data analysis technique algorithm(ISODATA) method, the improved OSTU algorithm is used for the threshold segmentation, finally the two processed images are fused. MATLAB simulation experiment results show that after the processing of the new segmentation algorithm, the image edge details characteristics of the target is more obvious, the outline is clearer,segmentation accuracy is higher and it is better to identify electronic components. It is full prepared for the feature extraction and setting up the infrared images database of the TCAS circuit board.