Speed Optimization Design Of Linear CCD Image Acquisition System Based On STM32

With the continuous development and application of high resolution and high frame rate CCD image sensor,the speed of image acquisition system is required to be higher.At present,the time of real-time storage of high-speed dynamic image in linear CCD acquisition system based on STM32 is too long,which results in slow system speed.Therefore,it is of great significance to optimize the speed of linear CCD image acquisition system based on STM32.In this paper,aiming at the problem of slow speed of real-time storage of high-speed dynamic image in linear CCD image acquisition system based on STM32,the method of speed optimization and software implementation of CCD acquisition system are studied.The main contents are as follows:Firstly,to carry out a linear CCD image acquisition system based on STM32.STM32F103ZET6 is selected as the main control chip,the function is to collect,store and transmit images;STM32F103C8T6 is used as the driver chip,which is responsible for the generation of CCD and A/D drive timing and the interaction with PC;TCD1209D is used as image sensor,as well as,AD9945 is selected as A/D conversion chip.Secondly,the system speed is optimized by shortening the time from generation,acquisition to storage of a frame of CCD image.This article separately optimizes the acquisition mode,storage mode and storage process as follows: replacing DMA single-buffered acquisition with DMA double-buffer acquisition,image acquisition and storage are performed simultaneously,so as to shorten image acquisition and storage time;on the basis of double buffering,multiframe acquisition and storage method is used to replace single frame acquisition and storage methods to shorten the image storage time;reducing unnecessary storage links in the data storage process to shorten the image storage time.Finally,software design.Completed CCD integration time adjustable drive and A/D drive design under multiframe acquisition and storage,acquisition design based on DMA double buffer,optimization design of storage process,interaction design between PC and STM32,etc.The test results show that the three methods of DMA double buffer acquisition,multiframe acquisition and storage,and storage process optimization can improve the system speed.When the three optimization methods are used at the same time,the system speed and frame rate can be significantly improved,and the system speed and frame rate with the increase of multiframe acquisition and storage,the number of frames increases.When the number of pixels in a frame of CCD image is 2100,the speed when the system is not optimized is 58KB/s,and the system frame rate is up to 27 frames/s.Three optimization methods are used at the same time and multiframe acquisition and storage are used The system speed during three-frame acquisition and storage reaches 485KB/s,which is 736% higher than the unoptimized system speed.At this time,the system frame rate reaches 232 frames/s.