Preisach逆补偿的GMA精密轨迹跟踪与实验优化

针对超磁致伸缩执行器(GMA)的非线性迟滞,研究了开环条件下采用Preisach逆模型对参考轨迹实现精密跟踪的补偿方法。简要介绍了经典Preisach迟滞数值模型,详细推导了Preisach逆模型及其数值实现方法。采用FFT数字滤波方法对一阶回转下降曲线 (FOD)实验数据进行优化处理,同时结合拉各朗日双线性插值方法,提高了在同等离散水平下Preisach模型对GMA非线性迟滞的预测精度。在精密预测的基础上,通过Preisach逆模型实现了GMA对参考轨迹的精密跟踪。实验结果表明:在0~34 μm,跟踪误差由补偿前的-14.7%~+11.2%减小到-2.9%~+2.7%。此外,FFT滤波和双线性插值算法可以明显提高Preisach模型对GMA非线性迟滞的预测精度,基于Preisach数值逆模型的补偿算法可以有效消除由于GMA非线性迟滞造成的跟踪误差。实验同时指出,如果要进一步提高跟踪精度,还须结合反馈实现闭环控制。

Precision tracking and experimental optimization of GMA by Preisach inverse compensation

In order to realize high precision tracking control of the Giant Magnetostrictive Administer(GMA), a numerical compensation approach was presented based on inverse Preisach model and a series of optimized experimental methods were discussed. The numerical expressions of the classical Preisach model were presented in detail for different input variations and the inverse classical Preisach model was established. The First Order Descending(FOD) datasets were obtained from the identification experiments and smoothed by a FFT filter. A good agreement between measured hysteresis loops and predicted curves shows that the FFT filter is an effective tool to cancel the errors and noises of the FOD datasets. In the tracking experiments, the Preisach inverse model was used to compensate the hysteresis of GMA to obtain a good tracking performance. On a moving range of 0~34 μm, the tracking error of the GMA with compensation is less than -2.9%~+2.7%, compared with the error of -14.7%~+11.2% without compensation. The experimental results indicate that the compensation approach based on numerical inverse Preisach model can greatly improve tracking performance of GMA, and the optimized experimental methods are effective.