永磁直线同步电机自适应非线性滑模控制

Adaptive nonlinear sliding mode control for permanent magnet linear synchronous motor

针对永磁直线同步电机(PMLSM)伺服控制系统易受参数变化、外部扰动、非线性摩擦力等不确定性因素的影响,采用了一种自适应非线性滑模控制(ANLSMC)方案。首先,建立了含有不确定性因素的PMLSM动态方程,然后,通过速度作为状态变量的非线性函数和广义滑模面相结合,设计了非线性滑模面,这样不仅提高了系统的响应速度,而且增强了系统的鲁棒性。通过自适应控制在线调整趋近律中的控制增益来调节系统状态轨迹到达滑模面的趋近速度,削弱了抖振现象,同时减少了系统跟踪误差,进而提高系统的控制精度。最后,实验结果表明所采用的控制方案有效可行,与滑模控制(SMC)和非线性滑模控制(NLSMC)相比,ANLSMC不仅提高了系统的响应速度,而且改善了系统的跟踪精度和鲁棒性能。

Adaptive nonlinear sliding mode control(ANLSMC)method was used for permanent magnet linear synchronous motor(PMLSM)servo control system which is vulnerable to influence of the uncertainties,such as parameter variations,external disturbances,nonlinear friction force and so on.Firstly,the dynamic equation of PMLSM with uncertainties was established.Then,the nonlinear sliding mode surface was designed by combining the nonlinear function of velocity as a state variable and the generalized sliding mode surface.It not only improves the response speed of the system,but enhances the robustness.The adaptive control was used to adjust the control gain to adjust the approaching speed of the system state trajectory to the sliding mode surface,which weakens the chattering phenomenon and reduces the tracking error.Therefore the control precision of the system is improved.Finally,the experimental results show that the used control scheme is effective and feasible.Compared with sliding mode control(SMC)and nonlinear sliding mode control(NLSMC),ANLSMC not only improves the response speed of the system,but improves the tracking accuracy and robustness of the system.