运动状态下柔性关节机器人关节面参数辨识研究

Joint parameter identification of a moving flexible joint robot

针对柔性关节机器人系统,提出了一种机构系统运动状态下关节面参数辨识的新方法。首先,将机器人柔性关节等效为弹性扭转轴,将应用于结构中的行波分析方法与机器人关节旋转变换矩阵相结合,建立机构系统的波导方程;其次,根据系统各结点力平衡与位移边界条件,建立运动状态下系统环境预测模型,并根据预测出的系统激励以及实验测得的关节扭转角等因素,建立系统振动方程;再次,利用最小二乘法对上述模型进行求解,推导出关节动态刚度和阻尼;最后,以两种不同的运动轨迹驱动3自由度机械臂,对其进行辨识实验研究。实验结果表明,该辨识方法是有效的,为后续系统的动态控制提供了重要参考。

A new approach to identify joint parameters of a flexible joint robot under movement was presented.Firstly,taking a flexible joint as an elastic twist axis,and combining the wave theory of structures with the rotating transformation matrix of a joint,the wave equations of the mechanism were established.Secondly,considering general force balance of all nodes and displacement boundary of each joint,the environmental prediction model of the system under moving states was deduced.Furthermore,the vibration equations were gained according to the predicted excitations and the tested joint twist angles.Thirdly,joint dynamic stiffness and damping were deduced after solving the former model by use of the least square method(LSM).Finally,parameters identification experiments of a 3-DOF manipulator were done under two different move trajectories.The experimental results showed that the proposed approach is effective and it can provide a reference for the further dynamic control.