基于名义模型的机械手PI鲁棒滑模控制研究

Research on Manipulator's PI Robot Sliding Model Control Based on Manipulator's Nominal Model

针对多关节机械手关节轨迹跟踪控制问题,将机械手动力学模型分解为名义模型和建模误差两部分,并对两部分用跟踪位置误差和速度误差定义滑模函数,对这两部分设计控制律,提出了基于名义模型的机械手PI鲁棒滑模控制方法.通过定义基于积分型的Lyapunov函数,证明了控制系统是全局渐近稳定的.利用该控制器对三关节机械手进行关节力矩控制,使三关节能在3s内实现对理想轨迹的跟踪,三关节均具有良好的位置跟踪和速度跟踪性能.仿真实验验证了控制器设计的有效性,并且通过合理选择控制器参数,能够消除滑模控制器输出所存在的抖振现象.

In order to attain trajectory tracking control for multi-links manipulator＇s joints, the manipulator＇s dynamic model was decomposed two sections, that is, nominal model and modeling error. The sliding mode function was defined with tracking position error and velocity error aiming at nominal model and modeling error, and the control law was designed for nominal model and modeling error. So, PI robust sliding mode control method was designed based on manipulator＇s nominal model. The control system＇s global asymptotical stability was proved through defining integral-type Lyapunov function. The PI robust sliding mode controller was used to control joints＇ torque for manipulator with three joints. Three joints can trace ideal trajectory in 3s. Three joints have favorable performance of position tracking and velocity tracking. Simulation experiments test and verify the designed controller＇s effectiveness. Espe- cially, the sliding mode controller＇s control output chattering can be eliminated through reasonably selec- ting controller＇s parameters.