Design of Real-time Displacement Measurement System Based on FPGA Image Processing hardware

Compared with the recognized standard precision measuring instrument laser interferometer, grating scale measurement has been widely used in industry because of its advantages of low price, high resolution and high precision. In the measurement system with a grating ruler as a sensor, displacement accuracy and real-time performance are important indexes to measure the whole system's performance. This paper presents a real-time displacement measurement system of FPGA grating ruler based on image processing. The system includes a grating ruler motion platform built by a high-speed camera, an integrated processing board for image processing, a macro-micro composite displacement calculation based on FPGA, and a human-computer interface. FPGA has the characteristics of high-speed real-time data acquisition and parallel processing, and can realize high-speed image acquisition and processing. Coupled with the robust image data transmission and storage ability of high-speed image capture cards, the FPGA displacement measurement system based on image processing can meet the real-time processing and displacement measurement under the condition of high-speed acquisition. In this paper, the real-time performance of the system is verified by processing and Simulation of the collected images.