Hardware Research On The Measurement System Of Ring Laser Resonant Cavity

With the development of the world military equipment, the helicopter is the absolutely necessarily military weapon. The high-powered reconnaissance helicopter is the development trend of world Army Airforce of PLA to adapt to the requirement from the modern war. The backstay form electronic-optical system is utilized in the reconnaissance and attack gunship, this electronic-optical system is installed in the top of the helicopter rotor, the fast circumrotation of the rotor would cover the outside scenery image, so the video image would appear the black and white flicker to prevent the observer observing image normally which would affect the detecting、capture、track performance. To resolve this problem, the image compensation technology can be researched to achieve the integrity and definition of the image to exert to the efficiency of the backstay form electronic-optical system.In this paper, the research refer to the shadow detecting of the image processing, dynamic image movement estimate and compensation technology. Based on the two techniques above, the arithmetic and project are advanced. The main work contain software arithmetic design and hardware achievement design.In the software design, the characteristics of the rotor shelter and the shelter shadow area are analyzed in detail, the result indicates that the image area gray scale average of list image is steady, the gray scale of the shelter area is variational evidently, the area gray scale characteristics is the parameter to judge whether the area is sheltered or not. So, the frame forecast arithmetic based on the area is advanced. This arithmetic can judge whether the area is sheltered or not availably, and check the shelter area.Secondly, for the movement video image list, movement estimation is very important, the compensation effect is impacted by the accurate of the movement estimation. In this paper, the gray scale projection method is utilized, and the project is advanced utilizing grayscale projection method to estimate image frame movement, combine to the shelter condition. The video image signal frame difference signal represents the more relativity than the frame border pixel difference signal, based on the theory above, the image can be forecast processed utilizing frame redundancy message to implement the rotor shelter area compensation. The rotor shelter area compensation is peculiar, because of the effect of the rotor shelter, the shelter image grayscale characteristic would change which should be considered when the image is compensated utilizing forecast grayscale. Based on the analyse above, the grayscale modify compensation arithmetic is advanced utilizing frame grayscale relativity.In the hardware design, based on the analysis of the structure、function and the application of the whole image compensation equipment, the choice of the apparatus and the design of the system principle diagram are accomplished. To ensure the accomplishment of the arithmetic function and the real-time, the DSP and FPGA are utilized which are used to process the odd field and even field respectively. The big capability are utilized to accomplish the storage of the multi-frame to ensure the supplying of the enough list image message when the image is compensated. The video decode chip is utilized by the video collecting input circuit and the video composing output circuit which improve the currency of the circuit board based on the function achievement. According as the principle of the high-speed signal design, the system PCB diagrams are designed to ensure that the circuit board accord with the signal integrality, the electrical source integrality and the requirement of the electromagnetism compatibility. Finally, the function of the video image compensation is achieved by the debugging to the circuit board.