永磁直线同步电机动态边界层全局互补滑模控制

Dynamic Boundary Layer Global Complementary Sliding Mode Control for Permanent Magnet Linear Synchronous Motor

为解决永磁直线同步电机(PMLSM)运行过程中对参数变化、外部扰动和摩擦力等不确定性因素敏感的问题,提出一种动态边界层全局互补滑模控制(GCSMC)方法。首先建立含有不确定性因素在内的PMLSM数学模型。然后利用广义滑模面和互补滑模面相结合的方式设计互补滑模控制器,来抑制不确定性因素对系统的影响,进而削弱抖振,但其边界层厚度值恒定不变,致使系统状态轨迹只能在边界层范围内收敛。为此,采用新型饱和函数来设计全局互补滑模控制器,以实现边界层的动态变化,使边界层厚度值随状态轨迹的变化而减小直至收敛到切换平面上,进一步提高了系统在边界层内的鲁棒性。实验结果表明该方法既改善了系统跟踪性能,又保证了系统的全局鲁棒性。

In order to solve the problem that permanent magnet linear synchronous motor(PMLSM)is sensitive to uncertainty factors such as parameter variations,external disturbances and frictions,a dynamic boundary layer global complementary sliding mode control(GCSMC)method was proposed.Firstly,the mathematical model of PMLSM including uncertainty factors was established.Then a complementary sliding mode controller was designed by combining generalized sliding mode surface with complementary sliding mode surface to suppress the influence of uncertainty factors on the system and then weaken the chattering.However,the thickness of boundary layer is constant,so the state trajectory of the system can only converge within the boundary layer.Therefore,a new saturation function was used to design a global complementary sliding mode controller to realize the dynamic change of boundary layer,which can reduce the boundary layer thickness with the change of state trajectory until it converges to the switching surface,thereby further improving the robustness of the system in the boundary layer.The experimental results show that the method not only improves the tracking performance,but also guarantees the global robustness of the system.