Research Of The Image Acquisition System Based On Linear CCD

In recent years，the rate of the development of Chinese agricultural mechanization isvery fast，specially precision seeder，has a strong promote momentum. The precisionseeder，as the most important and fundamental part of precision agriculture，itsperformance directly impact on the growth and yields of crops. Among the performancesof the precision seeder，uniformity of the distance between seeds is the most improtant，and studies of uniformity detection technology has always been the focus and hotspots ofprecision seeder performance testing technology.Based on the background of the test of uniformity of the distance between seeds，thispaper analysis of the existing detection methods，build a linear array CCD imageacquisition system based on DSP，and use the image acquisition system on the test ofuniformity of the distance between seeds，create a new way of testing.This article includes the following aspects：1．Research on linear CCD image capture technology in various fields，analyze thelack of the current technology of testing of uniformity of the distance between seeds，proposed the significance of linear CCD image acquisition system used in testing theuniformity of the distance between seeds.2．By studying the structure of precision seeder，designed a detection device，understand the principles of applications of linear CCD on size measurement，find outthe relationships between the length of the measured target，focal length options，thedistance of measured target and lens， the number and size of the pixel of the linear CCD.Complete the requirements analysis according to the system，pick the TCP1001P as theimage sensors.3．Analysis of the structure and characteristics of TCD1001P，design the drivingcircuit according the driving timing of TCD1001P，analysis the collection frequencyaccording the factors such as the operating speed of the precision seeder，the distancebetween seeds and the size of the seeds and so on. Analysis of the common noises of theoutput signal of CCD to design the signal processing circuit，select the comfortable A/Dconverter to converte the analog signals into digital signals.4．Using a combination of a DSP and FPGA to design the data storage system，analysis of the speed of the output of the A/D converter and the speed of the input of theDSP，use FIFO memory as the bridge between the A/D converter and DSP，design theFIFO based on FIFO. Introduce the DMA transfer mode，studied the SD card datastorage based on DSP，installation FAT32file system to SD card，and introduce theprocess of the data read and storage.