Research On The Detection System Of Foreign Fibers In Cotton Based On DSP+FPGA

In the processes that the cotton is picked, dried and transported, leaves, thread,hairs or chemical fibre are easily mixed in cotton, these impurities are called foreignfibers. Foreign fibers accounted for a small proportion in cotton, but these haveseriously and directly affected the quality of textile. For a long time, foreign fibersare removed by hand, which is low efficiency and high cost.With the eyes ofworkers are tire, removal effect is become low. So, foreign fibers are removed byhand, which can not meet the demand of modern industry of cotton spinning. In recent decade, several foreign companies have produced some kinds of equipmentwhich realize the function of removing foreign fibers from cotton. But foreigncompanies equipment is expensive, domestic cotton spinning enterprises can’tafford to the high cost. In addition, there are compatibility problems betweenimport equipment and the domestic existing equipment. More important, we havenot independent intellectual property rights and core technologies for importedequipment, so the technology of product is restricted by others country andupgrades can not follow. This subject is just proposed in the background, thepurpose is to develop the equipment for removing foreign fibers from cotton withour own intellectual property rights, reduce the cost of product and canconveniently provide the continuous upgrade service of product for enterprise.The reserch emphasis of this paper is how foreign fibers be identified fromcotton, and how to realize the image acquisition and recognition of foreign fibers inplatform of DSP+FPGA.The advanced technology of similar equipment in domestic and foreign isrefered when our project is researched, and the defect of similar equipment isavoided. In order to design the identification algorithm of foreign fibers, the current advanced algorithm of image processing is adopted and at the same time our owndemand is considered.In this paper, the architecture of DSP+FPGA is adopted inthe system. High performance DSP chip TMS320DM642is used as the coreprocessor, and FPGA chip is emploied as auxiliary processor. In a word, first lineararray CCD Camera with Camera link interface is used to capture image data of thehigh speed cotton flow, then DS90CR288A chip is applied to transform voltagedifferential signaling generated by camera into24bits RGB signal. Second, RGBdata is stored in the FIFO of FPGA, the data in FIFO is moved into SDRAM byEDMA. Finally, the image data in SDRAM is processed and identified by CPU ofDSP.At last, foreign fibers are fast identified by algorithm of dentification on DSP.The links of system that include Image acquisition, data transmission, imageprocessing and identification algorithms are realized, and the links are simple andefficient. This system fulfil efficient and intellectualized requirement for identifyingforeign fibers.