基于MPC和DOB的直线伺服控制系统设计

Design of Linear Servo Control System Based on MPC and DOB

数控机床用永磁直线同步电动机(PMLSM)在高速度高精度加工时存在的系统滞后、外部扰动、系统参数变化等不确定因素严重影响伺服系统的控制性能。为解决这一问题,提出将模型预测控制器(MPC)和扰动观测器(DOB)相结合的预测鲁棒控制系统。采用MPC作为前馈控制器,通过模型预测、滚动优化和反馈校正来提高系统的跟踪性能;采用DOB对外部负载等不确定性扰动进行观测和抑制,进而提高系统的鲁棒性,达到同时提高系统跟踪性能和鲁棒性的目的。仿真实验表明:所提出的控制方法是有效可行的,明显地提高系统的控制精度。

For NC machine with permanent magnet linear synchronous motor （PMLSM）,in the high speed and high precision machining,uncertain factors seriously affect the control performance of the servo system,such as the system decay,the external dis-turbances,parameter variations and so on. The predictive robust control system was proposed based on combining the model predictive controller （MPC）with disturbance observer （DOB）. The MPC was used as the feedforward controller,through model prediction, rolling optimization and feedback correction to improve the tracking performance of the system;DOB was used to observe and suppress external load uncertainty disturbance. So the robustness of the system is improved,to achieve the objective of improving system tracking performance and robustness. Simulation results show that the proposed method is feasible and effective,can obviously improve the con-trol precision of the system.