基于学习前馈补偿的直线伺服系统H_∞鲁棒跟踪控制

H_∞Robust Tracking Control for the Linear Servo System Based on the Learning Feedforward Compensation

针对直接驱动的永磁直线同步电机(PMLSM)伺服系统,在分析研究PMLSM的端部效应负载扰动及系统参数变化等不确定性因素对伺服系统性能影响的基础上,提出了一种将学习前馈控制和H∞鲁棒控制相结合的鲁棒跟踪控制策略。为消除端部效应的影响,采用基于B样条网络的学习前馈补偿控制技术,从而达到了良好的补偿效果;为克服不确定性扰动的影响,采用H∞鲁棒控制,从而保证系统有较强的鲁棒性。仿真结果表明,该方案保证了伺服系统快速而准确跟踪,同时有效地降低了不确定性扰动对系统性能的影响,从而提高了直线伺服系统的跟踪性能和鲁棒性能。

For the direct-drive servo system of permanent magnet linear synchronous motor (PMLSM), on the basis of the analysis of the linear servo system performance influences to uncertain factors such as end-effect and load disturbances of the PMLSM, and parametric changes of the system, a robust tracking control strategy based on combining learning feedforward control with H∞ robust control is proposed in this paper. In order to eliminate the influence of the end-effect, the learning feedforward compensation control technology based on B-spline network is adopted; therefore, the better compensation effect is obtained. In order to overcome the influence of the uncertainty disturbances, the H∞ robust control strategy is adopted, so this ensures the stronger robustness of the system. The simulation results show that the control scheme not only can ensure fast and accurate tracking performance, but also reduce the influence of the uncertainty disturbances; therefore, the tracking performance and robustness of linear servo system are improved greatly.