基于干扰观测器的机械臂改进趋近律的滑模控制

针对机械臂滑模控制中存在抖振的问题以及对外界干扰较为敏感的特性,设计了一种基于干扰观测器的机械臂改进趋近律的滑模控制策略。该策略在指数趋近律中引入饱和函数,提出了一种改进趋近律;根据系统动力学模型,对系统的不确定性和外部干扰采用干扰观测器进行观测;在此基础上设计系统滑模控制律,控制律对未观测的干扰进行补偿。仿真结果表明,控制策略能有效地抑制轨迹跟踪中的抖振问题,较好地克服外界干扰,保证系统的控制性能。

An Improved Reaching Law of Sliding Mode Control for Robotic Manipulator Based on Disturbance Observer

Considering the chattering problem and the sensitive characteristics of the external disturbance in sliding mode control,an improved reaching law for manipulator based on disturbance observer is designed.In this strategy,the saturation function is introduced into the exponential reaching law,then an improved reaching law is proposed.According to the system dynamics model,the disturbance observer is used to measure the uncertainty and external disturbance of the system.On this basis,the sliding mode control law of the system is designed to compensate the unobserved disturbance.The simulation results show that the control strategy can not only suppress the chattering effectively,but also overcome the external interference,which ensures the control performance of the system.