基于广义比例积分观测器的机械臂末端力/位置控制

Force/position control of robotic arm end-effector based on generalized proportional integral observer

摘要:

针对具有模型不确定和外部时变扰动的柔性机械臂末端力/位置控制问题,提出了一种基于广义比例积分观测器的间接力/位置控制方法。首先,根据阻抗模型描述机械臂在工作空间中接触面的最终位置和接触力之间的动态关系,并将系统中参数不确定以及外界扰动视为总干扰,接着采用广义比例积分观测器对未知扰动进行估计补偿,利用滑模控制技术设计非奇异快速终端滑模控制器,实现在无需计算阻抗参数的情况下使间接力/位置混合控制器在面对时变扰动时有更好的稳定性和鲁棒性。完成柔性机械臂的轨迹跟踪仿真实验,并验证所提方法的有效性。

Abstract:

Aiming at the end force/position control problem of flexible manipulator with model uncertainty and external time-varying disturbance, an indirect force/position control method based on generalized proportional integral observer is proposed. Firstly, the dynamic relationship between the final position of the contact surface and the contact force of the manipulator in the workspace is described according to the impedance model, and the parameter uncertainty and external disturbance in the system are regarded as the total disturbance. Then the generalized proportional integral observer is used to estimate and compensate the unknown disturbance, and the sliding mode control technology is used to design the nonsingular fast terminal sliding mode controller, so that the inter relay/position hybrid controller has better stability and robustness in the face of time-varying disturbance without calculating the impedance parameters. The trajectory tracking simulation experiment of flexible manipulator is completed, and the effectiveness of the proposed method is verified.