针对压电陶瓷(PZT)位移平台因迟滞特性而降低系统定位精度的问题, 该文采用了一种带有前馈补偿的复合型控制方法。首先建立前馈模型, 提出了一种分段式Prandtl-Ishlinskii(P-I)模型, 并对所建平台迟滞模型求逆, 其建模误差率在0.7%内; 然后针对闭环回路设计了串联比例-积分(PI)模拟电路、滤波电路和检测电路, 进一步提高了控制系统的响应速度和控制精度。实验结果表明, 压电陶瓷位移平台在频率为100 Hz, 行程为0~140 μm的情况下, 基于前馈补偿的复合控制系统的平均绝对误差为0.039 μm, 最大误差为0.16 μm; 与仅有前馈控制相比, 其控制精度提高了73.76%。

A composite control method with feedforward compensation was adopted to address the problem that the system positioning accuracy of the piezoelectric ceramic (PZT) displacement platform was degraded due to the hysteresis characteristics.First, a segmented Prandtl-Ishlinskii (P-I) model was proposed for the establishment of the feedforward model, and the hysteresis model of the constructed platform was inverted. The error rate of the model was within 0.7%.Then, a series proportional integral (PI) analog circuit, a filter circuit and a detection circuit were designed for the closed-loop, which further improves the response speed and control accuracy of the control system. The experimental results show that the average absolute error of the composite control system based on feedforward compensation is 0.039 μm and the maximum error is 0.16 μm for the piezoelectric ceramic displacement platform at the frequency of 100 Hz and the stroke of 0-140 μm.Compared with feedforward control only, its control accuracy is improved by 73.76%.