抑制滑模抖振的新型饱和函数法研究

Investigation of a novel method of saturation function for chattering reduction of sliding mode control

饱和函数控制法是抑制滑模抖振的有效方法之一,但由于边界层厚度的固定不变,导致系统轨迹无法渐近收敛到所给定的切换平面上,从而在切换平面上不存在滑动模态,降低了系统在切换平面上的鲁棒性.通过对以上问题研究分析,提出了一种具有动态边界层的新型饱和函数控制法.该控制方式可使边界层随状态轨迹的收敛而逐渐收缩,当边界层厚度减小到零时,边界层与切换平面重合,使状态轨迹最终收敛到切换平面上,增强了系统在切换平面上的鲁棒性.理论分析和仿真实验证明了该方法的可行性.

The saturation function control method is effective for reducing the sliding mode chattering, but due to changeless thickness of boundary layer, the system cannot achieve asymptotic stability,and has not sliding and robustness on sliding surface. A novel saturation function control method with dynamic bounda- ry layer is proposed by research and analysis. As the state trajectory nears the sliding surface,the boundary layer contracts and reaches the sliding surface while the thickness of boundary layer is zero, increasing the robustness of the system on sliding surface. Theory analysis and simulation experiment approve the novel control mode is feasible.