基于ADμC845的LVDT位移传感器非线性补偿

摘要

针对LVDT位移传感器测量电路输出电压值和位移量之间存在非线性特征,设计和制作线性度为0.05％高精度传感器比较困难的现状,在分析产生非线性误差主要原因和传统校正方法的基础上,利用单片机软件算法进行非线性校正以提高传感器设计精度.以传感器标定数据为样本,用曲线拟合法求出非线性校正环节的特性曲线,并给出在MATLAB环境下拟合多项式系数的最小二乘求解方法,编程实现位移量和电压输出.仿真分析和实验结果表明,其测量位移的线性度达到了设计要求,非线性校正效果明显,具有良好的应用价值.%Because the linear variable differential transformer(LVDT) displacement sensor measurement circuit has nonlinear relationship between output voltage value and displacement,it is difficult to design and product high precision sensor with 0.05％ linearity.In order to improve the design precision of the LVDT displacement sensor,nonlinear correction is performed using single-chip microcomputer software algorithm,after analyzing the main cause reason of the nonlinear error based on the traditional correction method.The characteristic curve of nonlinear correction link is obtained by fitting the sensor calibration data.And the polynomial coefficients are found by least square method with MATLAB software.Simulation and experiment results show that the nonlinear correction effect is very good,displacement measurement linearity can meet the design requirements,and this method has a good application prospect.