含有摩擦补偿的全方位移动机器人自抗扰控制

Active disturbance rejection control with friction compensation for an omnidirectional mobile robot

本文针对全方位移动机器人轨迹追踪中的摩擦补偿问题,提出了一种改进的非线性自抗扰控制器.首先建立了含有经典静态摩擦模型的全方位移动机器人动力学模型.其次,基于该模型设计非线性控制器和线性扩张状态观测器并给出了系统的稳定性分析.通过将模型已知项加入线性扩张状态观测器中得到摩擦力的估计值,并将估计值用于非线性控制器中摩擦补偿部分.为减小摩擦力对机器人低速运动轨迹追踪控制的影响,非线性控制器采用变增益控制器进行轨迹追踪控制.最后通过仿真结果验证本文提出控制器的有效性.

This paper presents an improved nonlinear active disturbance rejection controller with friction compensation,designed for trajectory tracking control of an omnidirectional mobile robot. The dynamic model with static friction model of an omnidirectional mobile robot is presented firstly. Based on this model, a linear extended state observer and a nonlinear controller are designed while the stability analysis is provided. To get the estimation of friction, the available model is added into the linear extended state observer and the estimation is used in friction compensation of the nonlinear controller. To decrease influence of friction when the robot is in low-speed, a variable gain controller is used in the nonlinear controller for trajectory tracking control. Finally, the simulation results are demonstrated to prove the controller effective for friction compensation.