一类欠驱动机械系统基于滑模的变结构控制

针对体操机器人这种欠驱动机械系统设计了滑模变结构控制律,变结构控制中采用了一种改进的指数趋近律·仿真结果表明对线性化模型所设计的变结构控制器应用在非线性系统中,仍能使机器人系统实现稳定·与极点配置方法相比较,采用滑模变结构控制方法设计的平衡控制器可使机器人系统具有更大的稳定范围(吸引域)和更强的鲁棒性·改进的指数趋近律可有效地降低变结构控制中所产生的抖动,并使系统迅速达到平衡稳定状态·

Variable Structure Control Based on Sliding Model for a Class of Underactuated Mechanical System

Presents the design of variable structure control law on sliding mode for Acrobots as a class of underactuated mechanical system, with a modified exponential approximation law employed in the design. The simulation results showed that an Acrobot system remains stable if the variable structure controller designed in terms of linear model is employed in nonlinear system. Comparing with the control by pole placement method, a bigger stability range (or basin of attraction) and stronger robustness can be provided for an Acrobot system by the balance controller which is designed by variable structure control based on sliding model. The modified exponential approximation law can not only reduce effectively the tremble caused by variable structure control but make the Acrobot system come to a stable equilibrium state quickly.