基于滤波器的自适应变结构机器人控制器研究

Study on Adaptive Variable Structure Controller with Filter for Robot

结合自适应控制和变结构控制的优点,设计了一种基于滤波器的自适应变结构机器人控制器.在控制信号输出端加滤波器,削弱由开关不连续性引起的系统抖振.利用机器人矩阵线性特征,将各模型参数误差表示为一列向量,基于Lyapunov能量法推导变结构控制率和模型误差向量的自适应率.实现在线估计参数误差,并基于估计值进行变结构控制,削弱由模型参数不确定性引起的系统抖振.针对实际机器人轨迹跟踪控制系统进行了仿真,结果表明控制策略的有效.最后,对滤波器削弱抖振的结构进行了分析与总结.

A novel adaptive variable structure controller is presented in this paper.To reduce output chattering,two measures have been taken into accounted.One is adding a low-pass filter to smooth the control signal from variable structure controller.another is the adaptive estimation of parameter＇s error between real and nominal one.Robot＇s parameter uncertainties are expressed and processed in a column vector according to robot＇s linear character,which simplify design procedure.The control law and adaptive rule are conduced using Lyapunov theory to ensure the errors converge.The simulation and experimental results of a trajectory tracking controller based on the scheme for a multi-link robotic manipulators confirm that the controller can guarantee the stability and dynamic quality,and eliminate the negative effects of parameters uncertainties in the systems on the performances.The robustness and good tracking precision can also be obtained.