基于新型补偿控制策略的柔性关节控制器设计

Design for Flexible Joint Controller Based on a New Compensation Control Strategy

柔性关节机器人控制系统中存在不确定性扰动、摩擦力、参数变化以及建模误差等问题,而常规PID控制无法兼顾稳定性和控制精度的要求,为此设计了一种基于新型补偿控制策略的柔性关节鲁棒控制器.控制器设计中,将摩擦力分为线性和非线性两部分,扰动分为确定性和不确定性两部分;机器人自身结构相关量、确定性扰动以及摩擦力的线性部分可以通过前馈补偿器进行有效控制;摩擦力的非线性部分、系统参数变化、不确定性扰动以及建模误差等通过所提的反馈补偿器补偿;并应用李亚普诺夫稳定性理论证明了该控制器的稳定性.最后在HIT四自由度柔性机械臂上进行了该控制器的相关实验,实验结果表明该控制器具有良好的位置跟踪性能和鲁棒性.

For the uncertain disturbance,friction and parameter variation,modeling errors and other issues in flexible joint robot control system,conventional PID control can not take into account both the requirements of stability and control accuracy.To solve this problem,a novel robust joint controller based on a new compensation control strategy is designed.In the controller design,the friction is divided into two parts,linear and nonlinear,and the disturbance into certain and uncertain. The part associated with the robot self structure,deterministic disturbance and the linear part of the friction can be controlled effectively by the feedforward compensation part.Feedback compensation part of the proposed controller can compensate nonlinear part of friction,system parameter variation,external uncertain disturbance,modeling error and so on.Its stability is completely proved by Lyapunov stability theory.Finally,the results on the platform of HIT 4-DOF flexible manipulator show that the controller has good position tracking performance and robustness.