基于扰动观测器的永磁直线同步电动机自适应反推互补滑模控制

Adaptive Backstepping Complementary Sliding Mode Control Based on Disturbance Observer for Permanent Magnet Linear Synchronous Motor

针对永磁直线同步电动机(permanent magnet linear synchronous motor,PMLSM)驱动的数控机床易受参数变化、负载扰动以及摩擦力等不确定性影响的问题,提出一种基于质量辨识扰动观测器(disturbance observer with mass identification,DOB-MI)的自适应反推互补滑模控制(adaptive backstepping complementary sliding mode control,ABCSMC)策略。设计ABCSMC方法抑制不确定对系统的影响。通过引入自适应律,ABCSMC的边界层能够实现动态变化,保证系统具有全局鲁棒性,且ABCSMC可对不确定性在线估计并调整,从而提高位置跟踪精度。由于在实际应用中,负载质量变化会对系统性能造成极大的影响,因此,利用离散模型参考自适应辨识理论,设计DOB-MI辨识动子质量并计算出补偿电流以补偿负载扰动对系统的影响。仿真与实验结果表明,该方法提高了系统的位置跟踪精度,对参数变化和负载扰动等不确定性具有极强的抑制能力。

In order to solve the problem that CNC machine tools driven by permanent magnet linear synchronous motor driven were easily affected by the uncertainties of parameter variations, load disturbances and friction forces, an adaptive backstepping complementary sliding mode control(ABCSMC)strategy based on disturbance observer with mass identification(DOB-MI) was proposed. The ABCSMC method was designed to suppress the influence of uncertainties on the system. By introducing adaptive laws, the boundary layer of ABCSMC could realize dynamic change, which ensures the system had global robustness, and ABCSMC could estimate and adjust the uncertainties on-line, so as to improve the position tracking accuracy. In the practical applications, the change of load mass would have a significant influence on the system performance.Therefore, DOB-MI was designed to identify the mass of the mover by using the discrete model reference adaptive theory,and calculate the compensation current to compensate the influence of load disturbances on the system. The simulation and experimental results show that this method improves the position tracking accuracy of the system, and has strong ability to restrain the uncertainties such as parameter changes and load disturbance.