The Circuit Design And Implementation Of The Cooling Infrared Imaging System Based On FPGA

The infrared imaging technology is a kind of high and new technology which can convert infrared radiation into visible image by photoelectric conversion.Nowadays,it is playing a more and more important role in the military and civilian fields.Image acquisition and processing circuit,as an important part of infrared imaging system,how to achieve high signal-to-noise ratio,high-speed transmission,acquisition and real-time processing of infrared signal has always been the research focus of infrared imaging system.With the rapid development of FPGA technology,a new solution is provided for this research.This paper mainly studies and designs the infrared imaging system based on field programmable gate array(FPGA).Firstly,the research background and significance of infrared imaging system are introduced in detail,and then the development and research status at home and abroad are analyzed.On this basis,according to the technical specifications of 640×512medium wave refrigerated focal plane array detector module,the detector bias circuit,signal preprocessing circuit,analog-to-digital conversion circuit,FPGA signal processing circuit and serial communication interface circuit are designed in hardware.In order to ensure the stability of signal transmission,the four analog signals output by the detector are transmitted in the form of differential signal.In the aspect of software,all kinds of timing control signals with FPGA as the core device are designed,which are responsible for providing stable working clock signal,Amax D conversion timing signal and memory control timing signal for the detector.Because of the non-uniformity of the infrared detector,the two-point correction method is used to correct the non-uniformity of the output infrared image,and the blind pixel compensation method which is beneficial to the spatio-temporal correlation is used to replace the blind elements in the focal plane array.And because the contrast of the output infrared image is low,the hierarchical sense of the image is not obvious,so it is necessary to enhance the image in the later stage.In order to solve the above problems in the output of infrared image,the non-uniform correction,blind pixel replacement and image enhancement of infrared image are realized by using FPGA hardware circuit.Finally,the hardware circuit and software code of the infrared imaging system are debugged respectively.A clear image is obtained through the imaging experiment,which verifies the feasibility of the system design and meets the design requirements of the project.