Design And Implementation Of Full Spectrum Industrial Camera System Based On FPGA

With the rapid development of machine vision,video and image applications are becoming more and more widespread,and people's requirements for image quality continue to increase.As the cornerstone and core part of machine vision,industrial cameras are responsible for converting the detected objects into digital or analog image signals,which basically determines the quality of the image.According to different application requirements,a variety of industrial cameras have emerged.Most of the existing industrial camera systems are aimed at the application of visible light range,mainly with the abroad image sensors,which are expensive in price but simple in functions.At the same time,image sensors may also be limited by the export of foreign countries in the future.Therefore,this paper uses domestic image sensor chip to develop a full spectrum industrial camera system based on FPGA.This system hardware can be compatible with GSENSE2020BSI and GSENSE400BSI two back-illuminated area array CMOS chips produced by Changguang Chenxin Optoelectronic Technology Co.,Ltd.,the system uses flexible programmable logic device FPGA as the main control chip and data processing core,which has high-speed and large-capacity.DDR3 is used as an image cache center,and high-bandwidth USB 3.0 is used as a data transmission interface between the FPGA and the PC,which can realize the video stream display of 4.2 million pixels@43 FPS.Through the program-controlled motorized filter wheel to switch the filters in a specific wavelength range,the camera can be used for industrial or scientific detection in the ultraviolet,visible light,and near-infrared bands,achieving multiple functions in one machine.In addition,a 7 pin aviation head I/O interface is reserved.On the one hand,it can trigger external signals isolated by GPIO or optocoupler,on the other hand,it can be used as external power supply interface.The software first uses FPGA for programmable logic development,which in turn implements interface protocol conversion,image sensor drive,high-speed data reception,data processing,and forwarding functions.Then,based on the high-speed frame cache function of DDR3,the image can be horizonal or vertical flipped,and the frame loss caused by the lack of bandwidth in the transmission of compatible USB 2.0 interface can be effectively improved.In addition,under the transmission interface of USB 3.0,the frame retransmission mechanism based on DDR3 is innovatively proposed,which enriches the function of DDR3.Then the firmware of USB 3.0 is developed to realize high-speed data transmission.Finally,based on C++,an easy-to-use upper computer software is developed to control and display the video stream in real time,realizing the functions of resolution switching,image effective bit depth switching,multi frame rate adjustment,exposure adjustment,gain adjustment,ROI,external trigger control,etc.Finally,based on the hardware and software systems,the board level debugging,overall performance test and the design reliability test are carried out to meet the industrial camera standard for mass production.Excellent results for modern industry and scientific research applications are also shown finally.