基于新型滑模面的机械臂快速轨迹跟踪滑模变结构控制

摘要

从滑模变结构控制的趋近运动和滑模运动两个阶段入手,分别对影响其性能的滑模面和趋近律进行了设计.首先,基于线性滑模面和终端滑模面,设计了一种具有较快收敛速度的新型非线性滑模面,以缩短系统在滑模运动阶段的运动时间.同时,根据幂次趋近律提出了一种改进的趋近律设计方法,保证了其趋近运动的速度,并减弱了传统滑模变结构控制所固有的抖振.最后,将该方法用于机械臂的滑模轨迹跟踪控制策略设计,仿真结果表明,该策略保证了机械臂对期望轨迹的快速跟踪,具有较强的鲁棒性,并且验证了控制策略的有效性.%The sliding surface and trending law are designed and the performance of reaching movement and sliding mode movement in sliding mode variable structure control are improved. A new nonlinear sliding surface is proposed based on linear sliding surface and terminal sliding surface. It can converge to the equilibrium point with a higher speed than former two surfaces in sliding mode movement. Then a new improved trending law is designed based on the power trending law which makes the system move toward the sliding mode with a high speed. And the buffeting is also decreased which is an inherent property of traditional sliding mode variable structure control. Lastly,this new method is used to design the tracking control scheme for the robotic manipulators. The simulation result shows that the control system is of high tracking speed and strong robustness. The validity of this method is proved.