基于低通滤波器的机械手滑模控制

Sliding mode control of manipulator based on low pass filter

机械手是典型的多输入多输出非线性系统,具有时变、强耦合、非线性、快速高精度跟踪等特点.滑模控制是机械手控制的一种重要方法,但基于一般滑模控制方法设计的控制器,其输出存在高频抖动,给被控对象带来不利影响.采用滑模结合低通滤波器的控制策略,定义滑模面,利用趋近律方法设计滑模控制律,基于李亚普诺夫(Lyapunov)函数证明系统的渐近稳定性.以双关节刚性机械手为例,MATLAB仿真结果表明,该控制策略能减小抖动、实现高精度跟踪.

The manipulator system is a typical multi input and multi output nonlinear system. It has the characteristics of time varying, strong coupling and nonlinear dynamics, high precision and fast tracking. Sliding-mode control is an important method for manipulator control, but the controller output designed by the general sliding-mode control method has strong chattering, which causes bad effects on plant. In the paper, a new control scheme of sliding-mode combined with low pass filter was described, and sliding-mode surface equation was defined. Based on the approach law, the control law was designed. At the same time, the asymptotic stability of the system was proved by Lyapunov function. MATLAB simulation about a two-link manipulator showed that the scheme could eliminate chattering and track with high precision and speediness.