基于扩展状态观测器的永磁同步直线电机自适应快速非奇异终端滑模控制

Adaptive fast nonsingular terminal sliding mode control based on extended state observer for permanent magnet synchronous linear motor

针对永磁同步直线电机(PMSLM)伺服系统的位置跟踪精度易受参数变化、负载扰动和摩擦力等不确定性因素影响的问题,该文提出了一种基于扩展状态观测器(ESO)的自适应快速非奇异终端滑模控制器(AFNTSMC).首先,采用了快速非奇异终端滑模面,在保证系统有限时间快速收敛的同时消除奇异性问题;然后,提出了一种新的自适应滑模趋近律(ASMRL),在抑制系统固有抖振的同时提高系统状态点趋近滑模面的速度;最后,考虑到高开关增益引起的高频抖振问题,设计了一个基于双曲正切函数的ESO来观测系统的不确定性扰动,作为前馈补偿以保证系统强鲁棒性的同时,削弱高频抖振.仿真实验结果表明,该方法提高了系统的瞬态响应速度和位置跟踪精度,在保证系统有限时间快速收敛的同时,拥有更好的动态跟踪性能,能够有效削弱抖振提高系统鲁棒性能.

An adaptive fast nonsingular terminal sliding mode control(AFNTSMC)based on extended state observer(ESO)is proposed to solve the problem that the position tracking accuracy of permanent magnet synchronous linear motor(PMSLM)servo system is easily affected by uncertain factors such as parameter variation,load disturbance and friction.Firstly,a fast non-singular terminal sliding mode surface is used to eliminate the singularity problem while ensuring the fast convergence of the system in finite time.Then,a new adaptive sliding mode approaching law(ASMRL)is proposed,which can suppress the chattering of the system while increasing the speed at which the system state points approach the sliding mode surface.Finally,considering the high frequency chattering caused by high switching gain,an ESO based on hyperbolic tangent function is designed to observe the uncertain disturbance of the system,which serves as feedforward compensation to ensure the strong robustness of the system and reduce the high frequency chattering.The experimental results show that the proposed method improves the transient response speed and position tracking accuracy of the system,ensures the rapid convergence of the system in finite time,and has better dynamic tracking performance,which can effectively reduce chattering and improve the robustness of the system.