采用变间隔阈值PI模型的压电平台前馈控制

发布时间：2018-07-17 20:35

【摘要】：为提高压电微动平台在运动过程中的定位精度,设计前馈控制器来控制平台输出位移。首先,根据压电微动平台迟滞曲线的特点,在不降低模型精度要求的前提下,对迟滞曲线非线性较大区域进行细密划分,对线性较好区域进行稀疏划分,进而建立了变间隔阈值的平台Prandtl-Ishilinskii(PI)迟滞模型;接着,通过对所建平台迟滞模型求逆,给出了平台的前馈控制算法;最后,将所设计的前馈控制器作用于平台,对其进行了实际控制。结果表明,在4μm的目标阶跃激励下,平台的响应时间为0.01s,无超调,稳态误差中线从无控制时的0.4~0.5μm减小为0~0.2μm;在最大值为20.7μm的幅值衰减三角波输入作用下,平台定位误差中线的最大正负差值从无控制时的3.82μm减小到1.15μm。所设计的控制器可有效减小压电微动平台的迟滞误差。
[Abstract]:In order to improve the positioning accuracy of the piezoelectric fretting platform, a feedforward controller is designed to control the displacement of the platform. Firstly, according to the characteristics of hysteresis curve of piezoelectric fretting platform and without reducing the precision requirement of the model, the large nonlinear region of hysteresis curve is partitioned in detail, and the better linear region is partitioned sparsely. Then, the platform Prandtl-Ishilinskii (Pi) hysteresis model with variable interval threshold is established, and the feedforward control algorithm of the platform is given by the inversion of the platform hysteresis model. Finally, the designed feedforward controller is applied to the platform. It is controlled in practice. The results show that under the target step excitation of 4 渭 m, the response time of the platform is 0.01 s, and the steady-state error center is reduced from 0.4 渭 m to 0.2 渭 m, and when the maximum value is 20.7 渭 m, the amplitude attenuates the triangular wave input. The maximum positive and negative difference of the center line of the platform positioning error is reduced from 3.82 渭 m without control to 1.15 渭 m. The designed controller can effectively reduce the hysteresis error of piezoelectric fretting platform.
【作者单位】：宁波大学机械工程与力学学院;
【基金】：浙江省高等学校中青年学科带头人学术攀登项目(pd2013091)
【分类号】：TN384;TP273

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