基于ZPET-FF和ESO的直线伺服鲁棒跟踪控制

提出一种将零相位误差跟踪和前馈(ZPET-FF)与扩张状态观测器(ESO)相结合的重复控制方法,以提高宏动台直线电机伺服系统的跟踪性能.以ZPET-FF作为前馈跟踪控制器,将信号估计器估计的跟踪误差和系统的实时误差作为其输入信号,将控制器对系统的跟踪误差进行实时补偿,以降低参数变化对系统的影响,有效提高系统的带宽和跟踪性能,减小系统的动态跟踪误差;采用ESO补偿系统中的各种扰动抑制噪声,以提高系统的抗干扰能力.实验结果表明,所提出的控制方法不仅提高了系统的动态跟踪性能,而且减小了系统的跟踪误差.

Linear Servo Robust Tracking Control Based on ZPET-FF and Extended State Observer

An nm level positioning precision and high-speed were required by using macro movement of long stroke linear motor and high-precision micro movement of planar motor in the wafer stage of lithography. In order to reduce the movement scope and acceleration of planar motor, the tracking precision of linear motor must be improved. Therefore, this paper presented a combined repetitive control strategy based on the combination of zero phase error tracking-feed-forward (ZPET FF) controller and the disturbance observer (ESO). The ZPET-FF was used as the feed-forward controller, which used the real-time compensation of the controller according to the tracking error of the system, so that the influence of parametric variation of the system and the dynamic tracking error of the system could be reduced, while ESO reduced the influences of the uncertainties, suppressed the system noise and improved the anti interference ability of the system effectively. The experiment shows that the proposed control method not only improves the dynamic tracking performance of the system, but also reduces the tracking error of the system.