基于 Preisach 模型的磁致伸缩位移传感器迟滞补偿方法

迟滞是磁致伸缩位移传感器测量误差的主要来源之一,减小迟滞可以显著提高传感器的测量精度。根据铁磁材料的磁滞特性分析了位移迟滞的形成过程。针对磁致伸缩位移传感器在短行程中仍存在较大迟滞的问题,将传感器整体视为迟滞系统并通过Preisach模型描述其输入输出关系,然后在此基础上提出了一种软件层面上的迟滞补偿方法,将迟滞曲线分段线性化以计算迭代初始值并根据稳态误差确定收敛值的搜索范围。为解决理论模型在磁环转向后的一小段距离内与实际偏差较大的问题,在转向点附近对迭代过程中的收敛条件进行调整,有效提高了补偿方法在该区域内的准确性。实验结果表明,该方法所需的迭代次数较少,且经过补偿后,传感器的迟滞降低至原先的1/3左右,非线性度也得到了小幅度提升。在不改动现有传感器结构的前提下,该方法可快速、有效地降低传感器的位移迟滞,为磁致伸缩位移传感器的迟滞补偿提供了一种新的方案。

A hysteresis compensation method of magnetostrictive displacement sensor based on the Preisach model

Hysteresis is one of the main sources of measurement errors for magnetostrictive displacement sensors ( MDS ). The measurement accuracy of the sensor can be significantly improved by reducing hysteresis. According to the hysteresis characteristics of ferromagnetic materials, the formation process of the displacement hysteresis is analyzed. To address large hysteresis in the short stroke of MDS, the Preisach model is used to describe the input-output relationship of hysteresis system which represents MDS. Then, a software compensation method for hysteresis on this basis is proposed, which linearizes the hysteresis curve piecewise to calculate initial iteration value. The search range of convergence value is determined according to the steady-state error. To solve the problem of the large deviation between the theoretical model and reality within a short distance after the magnetic ring turns, the convergence condition is adjusted near the turning point to improve the accuracy of the compensation method in this area. Experimental results show that the method requires only a few iterations. After compensation, the hysteresis of MDS is reduced to about 1 / 3 of the original value. The nonlinearity is also slightly improved. Without changing the existing sensor structure, this method can quickly and effectively reduce the displacement hysteresis of the sensor. It provides a new solution for the hysteresis compensation of MDS.