刚度控制机器人的机构稳定性设计

刚度控制机器人需要提高与任意环境接触或交互的稳定性,使机构末端可在较小位移下实现较大输出力。从机构参数模型出发,以任意环境下可稳定达到的最大控制刚度来衡量机构的稳定性或稳定范围,并考虑各向同性,研究机器人参数设计理论与方法。以一种2自由度机构设计为例,首先建立动力学模型并分析其耦合特性;然后对各解耦运动链的等效单自由度模型作稳定性分析,给出机构最大稳定控制刚度的定量表示;最后对两组具体参数进行校核和对比分析。结果说明:电机输出轴径、传动比和关节杆长等参数对机构稳定性影响较大,可通过调整这些参数来改善机构刚度控制的性能。

Stability design of a stiffness-controlled robot mechanism

The stability of a stiffness-controlled robot interacting with an arbitrary environment was studied using a mathematical model of the robot mechanism to achieve a desired force with a relatively small displacement.The parametric design method considers the dynamic isotropy with a maximum controlled stiffness to evaluate the mechanism stability which will guarantee system stability in any environment.A 2-DOF mechanism was used as an example to demonstrate the method along with analytical model of the stability of two equivalent 1-DOF models with uncoupled joints.The results show that the motor output diameter,the transmission ratio,and the link length all affect the robot stability and that adjustments of these parameters can improve the performance of a stiffness-controlled robot.