机器人三关节运动跟踪路径定位滑模控制

Sliding Mode Control for Robot Three Joint Motion Tracking Path Location

为了提高空间三关节机器人轨迹跟踪控制性能,提出一种基于低通滤波器的滑模控制方法。传统滑模控制响应速度快,对系统参数摄动和外部扰动等不确定因素具有不变性,可保证系统的渐进稳定性,但其缺点是控制本身会引起系统较强的抖振,造成跟踪精度较差。因此在传统的滑模控制方法中引入低通滤波器,则保证了轨迹跟踪误差的快速收敛,同时实现控制器输出信号的平滑,有效的减弱了抖振。系统的稳定性通过李亚普诺夫定理证明。通过对空间三关节机器人进行仿真,结果表明在存在模型误差和外部扰动的情况下,提出的方法能有效提高关节机器人跟踪控制性能,同时可以较好的消弱系统抖振。

In order to improve the trajectory tracking control performance of three-links spatial robot, a new slid- ing mode control method with low-pass fiiter is proposed. Due to fast response speed and invariant to system parame- ter perturbation and external disturbance uncertainties, traditional sliding mode control can assure the asymptotic sta- bility of the system, but its disadvantage is that the control itself may cause strong system chattering which results in poor tracking accuracy. Therefore, a low pass filter was introduced on base of the traditional sliding mode control method. The control law can guarantee fast convergence of trajectory tracking error as well as actualizing the smooth- ness of the output signal of the controller, and thereby the chattering was weakened effectively. The stability of the system was proved by Lyapunov theorem. Finally the simulation was carried out for a three-links spatial robot, the simulation results show that the proposed method is effective to improve the robot tracking control performance in the presence of model error and external disturbance^and to weaken the chattering better.