Research Of Machine Vision System Based On FPGA

In recent years,the application of machine vision is growing rapidly and has stepped into every field of our modem life. Detection based on machine vision has become an important development direction for fabric defect detection. Because of high speed and heavy computation, traditional processers based on serial instructions can hardly meet the the needs of high-speed and real-time image processing. How to improve the image detection processing performance with hardware has become a hotspot issue.With the fast development of microelectronics,the good performance of field programmable gate arrays (FPGA) brings machine vision system design a new method. Due to the great characteristic that design can be realized by FPGA's reconfigurable hardware resources, it is better to substitute hardware parallel implementation for traditional software serial implementation and it is very easy to improve the design parallelism so as to increase image data throughput. The method has been specially adapted for image processing and other computing intensive operations using SIMD structure operation that can accelerate processing obviously.In this paper, a new implementation scheme of fabric defect detection based on machine vision is introduced. Design uses hardware to realize fabric defect detection algorithm . The target is to capture high-speed fabric images for real-time defect detection. The whole system is made up of detection system platform and fabric defect detection algorithm which are both designed based on FPGA's internal programmable hardware resources. The design contains Camera Link interface design, SRAM interface design, the defect detection algorithm design, VGA display interface and Serial communication interface design etc. Among them,the hardware implementation of defect detection algorithm makes full use of FPGA's structure to improve flexibly and applies pipeline technology to operation module to get higher throughput rate,which make the implementation of defect detection algorithm based on FPGA more efficiency.The whole system is designed with QUARTUS II 8.0 as design environment and VHDL (Very High Speed Integrated Circuits Hardware Description Language)as design input. In addition,the design uses the simulation tool Modsim6.1f for simulation.At last, the system verification is finished on Altera's FPGA device Cyclone II EP2C35F . Through debug and verification, the design can capture the high-speed fabric images and detect fabric defect correctly. The results show that the design reaches its design effect on time and function .