Study On Multifunctional Data Acquisition Card Based On DSP

This paper arms to design a multi-function data acquisition card for a high-end surface topography measurement instrument. To realize the multi motors control, multi channels of sensor data acquisition, piezoelectric ceramic driving, grating measurement and CCD external trigger control etc. The specific work and achievements of this paper are as follows.Have analysised the basic requirements and the main technical indicators of multi function data acquisition card. Taking advantage of FPGA's parallel processing ability and high speed data processing ability of DSP, combined with the fast USB2.0 communication interface, designed the overall scheme of data acquisition card based on DSP+FPGA+USB2.0. In this scheme, the time consuming peripheral equipment processed by the FPGA and DSP focuses on intensive floating-point data processing and analysising, and let data acquisition card achieving higher efficiency.Using multivariate function differential method, we analyzed the influence of grating sensor signal with unequal amplitude error, DC drift error, non orthogonal error on precision of displacement measurement, and we put forward a real-time error correction algorithm based on least square method.Completed program design of the FPGA peripheral control, DSP data processing analysis and correction, data communication of USB on lower computer.Combined with the design of the hardware and function program of machine, we completed the data acquisition card, and the whole function was tested and applied in experiment, the result is satisfactory.