基于ZPETC-FF和DOB的精密运动平台控制

Controller design based on ZPETC FF and DOB for precision motion platform

摘要:

光刻机的工件台和掩模台采用长行程直线电机宏动跟随平面电机高精密微动的复合运动方式,实现系统高动态纳米级精度的跟踪定位. 为减小平面电机的运动范围和加速度,必须提高直线电机精密运动平台的跟踪精度. 提出一种零相位误差跟踪控制器加前馈(ZPETC-FF)和干扰观测器(DOB)相结合的复合控制方法,以提高直线电机宏动精密运动平台的运动精度. ZPETC-FF作为前馈跟踪控制器,有效提高了系统带宽和跟踪性能,减小了系统的动态跟踪误差；DOB作为鲁棒反馈控制器,补偿了外部扰动、未建模动态和系统参数摄动等,有效提高了系统的抗干扰能力. 实验表明,所提出的控制方法与传统的控制方法相比,不仅提高了系统的动态跟踪性能,而且还具有更强的抗干扰能力.

Abstract:

An nm-level positioning precision and high-speed are 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, so this paper presents a combined control strategy based on the combination of zero phase error tracking controller with feed forward (ZPETC-FF) and the disturbance observer (DOB). ZPETC-FF is feed forward controller, which improves the system bandwidth and tracking performance effectively, and reduces the system′s dynamic tracking error, while DOB reduces the influences of the uncertainties, such as external load disturbances, unmodeled dynamics and system parameter perturbation. The experiments show that compared with traditional control method, the proposed control method not only achieves more rapid and accurate tracking of the system, but also has stronger anti-interference ability.