为提高轮廓加工精度采用DOB和ZPETC的直线伺服鲁棒跟踪控制

Linear Servo Robust Tracking Control Based on DOB and ZPETC to Improve the Contour Machining Precision

为了提高轮廓加工精度,本文针对高精度直线伺服系统,提出了一种将零相位误差跟踪控制器(ZPETC)和干扰观测器(DOB)相结合的鲁棒跟踪控制策略。ZPETC作为前馈跟踪控制器,保证了快速性,使系统实现准确跟踪;基于DOB的鲁棒反馈控制器补偿了外部扰动、未建模动态、系统参数变化和机械非线性等,保证了系统的强鲁棒性能。仿真结果表明了所提出的控制方案是有效的,既能实现完好跟踪,又有较强的鲁棒性能。从而有效地减小了轮廓误差,提高了轮廓加工精度。

To improve the contour machining precision in high precision linear servo system, a robust tracking control strategy based on combining zero phase error tracking controller （ZPETC） with the disturbance observer （DOB） is proposed in this paper. ZPETC is designed to ensure that the system has fast tracking performance and implements exactly tracking; While robust feedback controller based on DOB can overcome influences of the uncertainties of the parameters perturbation, the external load disturbances, unmodelled dynamic and mechanical nonlinearity, and achieve the stability and robustness of the system. The simulation results show that the proposed control scheme not only can enhance the fast tracking performance in the linear servo system, but also has a strong robustness to parametric variations and resistance disturbances. Thus the contour error is reduced effectively, and the precision of the contour machining is improved greatly.