宏微复合平台切换定位的耦合效应与解耦控制

Coupling Effect and Decoupling Control of Positioning Process of Macro-micro Composite Stage

为了实现宏微复合平台的精密定位,防止压电陶瓷行程饱和,对宏微平台之间的耦合影响进行了研究,分析了宏微平台耦合效应的产生机理,提出基于干扰观测器的前馈补偿解耦复合PID控制方法,保证微平台对宏平台误差的精密补偿。通过对直线电机系统和宏微平台之间的耦合传递函数进行模型辨识,设计了干扰观测器(DOB)和前馈补偿解耦控制器,并结合PID控制组合成为复合控制,在宏微复合平台上开展实验研究。实验结果表明:复合控制下的宏动台耦合位移的绝对值平均减小79.46%,压电陶瓷进行微定位时的行程平均减小38.83%,微定位时间至少减小43.37%。从而验证了该文所提方法的有效性。

In order to realize the precise positioning of the macro-micro composite stage,to prevent the piezoelectric ceramics from going to the end of its stroke,the coupling effect between the macro and micro stage is studied.After analyzing the mechanism of coupling effect,we proposed a feedforward compensation decoupling composite PID control method based on disturbance observer to ensure the micro-motion stage compensates the error of macro-motion stage.The linear motor system and the coupling transfer function between the macro and micro stage was modeled,and the disturbance observer(DOB)and feedforward compensation decoupling controller was designed based on identification models,to become composite controller combined with PID.We conducted experimental research on the macro-micro composite stage,experimental results indicate that the absolute value of coupling displacement of macro-motion stage under composite control is reduced by 79.46%on average,and the average stroke of the piezoelectric actuator is reduced by 38.83%,and the time of micro-motion stage positioning is reduced by at least 43.37%.The effectiveness of the proposed method is verified.