基于迭代学习控制的混合误差轮廓控制

针对永磁直线同步电动机直接驱动XY平台系统中存在不确定扰动的问题,单轴上设计了基于干扰观测器的迭代学习控制器.迭代学习控制器可以抑制重复扰动,干扰观测器可以消除非重复扰动的影响,两者结合起来可增强系统对重复和非重复扰动的抑制能力.由于轮廓误差计算模型要求跟踪误差远小于期望轮廓曲率半径,所以设计了混合误差轮廓控制器,跟踪误差较大时只控制各轴位置,跟踪误差足够小时进行轮廓控制.仿真结果表明,该控制方法使直接驱动XY平台具有较强的鲁棒性和较高的轮廓精度.

Hybrid error contour control based on iterative learning control

In order to avoid the uncertain disturbance in the direct drive XY table system of permanent magnet linear synchronous motor(PMLSM), an iterative learning controller based on the disturbance observer was designed on the single shaft. The iterative learning controller can restrain the repetitive disturbance, and the disturbance observer can eliminate the influence of non-repetitive disturbance. The combination of iterative learning controller and disturbance observer can enhance the ability of system for restraining both repetitive and non-repetitive disturbances. Because the contour error computing model requests that the tracking error should be far less than the expected contour curvature radius, a hybrid error contour controller was designed. When the tracking error is larger, only the position of each axis is controlled. When the tracking error is small enough, the contour control is performed. The simulated results show that the proposed control method makes the direct drive XY table exhibit stronger robustness and higher contour precision.