Research On Uncooled Infrared Thermal Imaging System Based On FPGA

With the rapid development of infrared thermal imaging technology,infrared thermal imaging systems are increasingly applied to military,civil,medical and other fields,especially uncooled infrared focal plane arrays based on uncooled infrared focal plane arrays.The advantages of small size,low power consumption and high stability have become one of the main development directions in the field of infrared thermal imaging.The uncooled infrared focal plane causes the non-uniformity of the infrared focal plane array and the blind element to seriously affect the imaging quality due to defects in its own materials and processes.Therefore,it is necessary to perform non-uniformity correction and blind element compensation for the infrared image.Based on the discussion of the principle of infrared thermal imaging system this paper designs an uncooled infrared thermal imaging system based on FPGA.The system adopts a single-chip FPGA architecture.The system consists of uncooled infrared detection module,analog signal modulation circuit,bias voltage generation circuit,TEC temperature control module,FPGA minimum system,external storage module,Ethernet transmission module and host computer.It mainly completes the functions of collecting,processing,transmitting and displaying the image information of the measured object.After the system is powered on,the uncooled infrared detector collects the infrared image signal of the measured target under the timing drive provided by the FPGA and the correct bias voltage,and then the FPGA controls the hardware protocol stack chip W5300 to process the infrared image data of the FPGA.It is sent to the host computer for real-time display and storage,and finally the design of the uncooled infrared thermal imaging system based on FPGA architecture is completed.In the system imaging process,the software part mainly includes four parts:the timing drive design of the uncooled infrared detector,the infrared image processing,the Ethernet transmission control and the upper computer.After introducing the characteristics and causes of infrared focal plane array non-uniformity and blind elements,this paper uses two-point temperature non-uniformity correction algorithm and dynamic fast median filtering blind element compensation algorithm for infrared image processing,while using Verilog HDL hardware.The description language implements the timing drive of the detector and the logic design of the 100M Ethernet data transmission based on TCP/IP protocol,and is verified by the simulation software Modelsim.After software and hardware debugging,it is confirmed that the miniaturized and low-power uncooled infrared thermal imaging system designed in this paper realizes the functions of high-speed acquisition and long-distance transmission of infrared images.