基于实时位置补偿直接驱动XY平台轮廓控制

Contour control for direct drive XY table base on real-time position compensation

永磁直线同步电机驱动XY平台系统在跟踪自由曲线时轮廓精度会受轨迹时变性的影响,系统中存在的周期性扰动也会降低轮廓加工精度.针对上述问题,采用适用于多轴非线性轮廓控制的实时轮廓误差计算算法,建立可用于自由曲线跟踪的XY平台的实时轮廓误差模型.利用实时位置补偿与交叉耦合控制相结合的控制方法减小轮廓误差.单轴系统采用IP(积分比例)控制与速度前馈控制相结合的复合控制器.理论推导与仿真结果表明,该方案能够有效地提高系统的轮廓精度,同时能较好地抑制系统周期性扰动的影响.

The time variation of free-form contour following task will influence the contour accuracy of direct drive XY table driven by permanent magnet linear synchronous motor.The periodic disturbances of the system can also reduce the contour machining precision.The real time contour error calculation algorithm applicable for multi-axis nonlinear contour control was adopted to solve the above problems.The real time contour error model of XY table for free-form contour following task was built.The position error compensator（PEC） and the cross-coupled control were combined to reduce the contour error.A compound controller combining the IP（proportion-integration） control with speed feed-forward control was used for the single axis system.The theoretical analysis and simulation results show that the present scheme can improve the contour accuracy of the system effectively and suppress the periodic disturbances of the system preferably.