The Research Of Data Acquisition System For Linear CCD Based On FPGA

In this paper, linear array TCD2252D is used as front sensor,and programmablelogic device FPGA controls the whole system to acquire and transfer the three channelRGB signal of the CCD.Then the data which is transferred to computer can bedisplayed.The whole system consists of CCD driving logic circuit module described inVerilog HDL,processing circuit of CCD output signal,high speed channel switch,highspeed A/D converter and data acquisition,dual-port RAM data cache module,high speeddata transfer.The system can realize accurate acquisition,display and storage of CCDoutput pixel combined with data collection tool.The system can be applied to thedetection of object contour size.The whole issue of the design, the contents are asfollows:1.In the study of linear array CCD working principle,and analysis of TCD2252Dfunction characteristic,as well as driving timing requirements.Xilinx FPGA is used asdesign platform and the driving timing is generated in Verilog language.It can easilydrive three linear array CCD.2.Considering the characteristic of CCD output video signal,and it also containseffective AC signal, DC component,and various noise.We design the filter and amplifiercircuit.As a result,the noise the CCD output signal contained is reduced,the problemswhich are very small amplitude and negative signal of the output signal are resolved, thequality of output video signal of CCD is improved.3.According to the characteristic that is high speed analog signal of the linearCCD.We design the high speed data acquisition system.It consists of RGB three highspeed analog channel switch,analog-digit converter,dual-port RAM data cache,logiccontrol module,and integrated logic analyzer Chipscope Pro developed by Xilinxcorporation.The system realize the synchronous acquisition and transmission of data,display of waveform.4.The Data acquisition system is used to detect object shape with the specificdimension. Multiple groups of image data are collected andanalyzed,calculated.Then,analyzing the influence factors of the whole acquisitionsystem and giving some feasible measures to solve.