压电微动平台的极点配置PID控制

为提高压电微动平台的位移输出精度,设计极点配置比例、积分、微分(PID)控制器对其进行控制。首先,在对压电执行器进行电学特性、机电特性分析的基础上,建立了压电执行器的数学模型;其次,在对平台进行受力分析、运动分析的基础上,建立了平台的动力学模型;然后,在保持平台极点虚部不变,且将系统闭环阻尼比取为1的情况下,将平台极点沿着平行于实轴的方向平移,设计出平台的PID反馈控制器;最后,实验验证了所设计控制器的有效性。实验结果表明,所设计的控制器可使平台具有较快的响应,在不考虑传感器噪声水平的情况下,平台在控制系统作用下的定位误差基本为0。

Pole Configuration PID Control of a Piezoelectric Micro positioning Stage

For the purpose of increasing the displacement output accuracy of the piezoelectric micro positioning stage, the pole configuration proportional, integral, derivative(PID) controller is designed to control the stage. Firstly, based on the analysis of electrical and electromechanical characteristics of the piezoelectric actuator, the mathematical model of the piezoelectric actuator is established. Secondly, based on the force analysis and motion analysis of the stage, the dynamic model of the platform is established. Then, when the imaginary part of the pole of the stage is kept unchanged, and the closed loop damping ratio of the system is taken as 1, the pole of the stage is translated along the direction parallel to the real axis, and the PID feedback controller of the stage is designed. Finally, the effectiveness of the designed controller is verified by experiments. The experimental results show that the designed controller can make the platform response faster. Without considering the sensor noise level, the positioning error of the platform under the control system is basically zero.