The Design Of Cooled Infrared Imaging Circuit Based On FPGA

The main feature of the cooled infrared imaging system is that it's system components has a chillers,which are mainly used to cool the infrared detector and make its working temperature keeping at a certain low temperature,thus ensuring the sensitivity of the infrared detector and reducing the thermal noise generated by the system itself.Therefore,the cooled infrared imaging system has better sensitivity performance.The common cooled infrared imaging system is Stirling cooled infrared imaging system.Infrared imaging circuit includes detector driving circuit,signal processing circuit and power transforming circuit,etc.It is an important component of infrared imaging system.The detector driving circuit completes the functions of signal acquisition,analog-to-digital conversion and signal processing of analog video signals which is outputed by the detector,and sends the output signals to the signal processing board.The signal processing circuit mainly includes FPGA processing circuit,peripheral memory circuit,imaging interface circuit,etc.After the infrared detector is produced,the imaging processing circuit determines the performance of the imaging system.In this paper,an infrared imaging system based on FPGA is developed to drive640×512 cooled medium wave infrared detector.XILINX's high performance FPGA device which is named XC5VSX95 T is used as the core in this design,and the detector driving circuit and signal processing circuit are designed to form the infrared imaging circuit.This paper expounds with the overall framework of the system,and introduces the detector components and infrared image processing technology which is used in this paper,focusing on the hardware platform construction and software platform construction.The nonuniformity correction,blind pixel compensation,image enhancement and image scaling algorithms are also introduced.The language Verilog is used to design and simulate each module in the system.