Design And Implementation Of X-ray Image Acquisition And Processing System Based On FPGA

The X-ray security inspection machine has become an essential security inspection device for access to densely populated traffic such as subways,bus stations,railways and customs.The X-ray security inspection machine is composed of a linear array X-ray image acquisition and transmission system and a host computer.The image acquisition and processing system is an important component of the X-ray security inspection machine,and provides image data for the PC upper computer.According to the development trend of security inspection machines at home and abroad,this paper mainly studies the X-ray image acquisition and transmission system,proposes the circuit scheme of the X-ray detection system,and implements the X-ray detection system data based on Altera's cyclone IV series FPGA controller.Real-time acquisition processing and transmission.Through the analysis of the characteristics of the X-ray security inspection system components and the system functions,the paper adopts the corresponding design method of modular image data acquisition and transmission,including the detection board,acquisition board and data board.For the X-ray detector solution in the detector board,a sensor consisting of 64 array diodes with a pixel pitch of 1.6 mm and the array diodes are back-illuminated for higher sensitivity uniformity and smaller pixel changes.According to the characteristics of the front-end amplifier,the acquisition board explores the amplification linearity of the amplifier type to the detector output signal.It proposes a 32-channel integrated charge amplifier solution.Under the condition of ensuring the adjustable gain of the weak current amplification,the channels are The uniformity of the uniformity.According to the working timing and output signal range and performance index of the multi-channel integrated charge amplifier,a 16-bit,1 Msps analog-to-digital converter is used to sample the image data.According to the application scenario of the security inspection machine,the ideal analysis of the data transmission distance and image transmission rate,the Gigabit Ethernet transmission data solution is designed to ensure the stability and accuracy of data transmission,and also increase the output distance.The upper limit.Finally,the paper carries out functional simulation and board level test on the overall data acquisition control timing and Gigabit Ethernet data transmission.The simulation test mainly includes the stability of the X-ray detection system and the correctness of the logic control.The text uses multiple cascading daisy-chain data transmission functions and Gigabit Ethernet data transmission.The test shows that the X-ray detection hardware circuit scheme and FPGA-based logic control used in this paper successfully complete the acquisition of X-ray image data.Transmission,and the indicators meet the application environment of the X-ray detection system.