Stewart并联机器人力敏感性分析及实验验证

Force Sensitivity Analysis and Experimental Validation of Stewart Parallel Manipulator

研究了Stewart并联机器人的人机交互安全性问题.首先建立机器人的静力学方程,提取关节力敏感度和关节力敏感方向指标,度量关节力对操作力的感知敏感性.采用解析法和数值法结合的方法求算关节全局力敏感度.接着分析关节力敏感度在笛卡儿工作空间和位姿工作空间中的分布,以及构型参数对关节全局和局部力敏感度的影响.然后通过限制工作空间和调节末端执行器在工作过程中的位姿,在设计阶段合理选取构型参数,改善关节力敏感度的方法提高人机交互安全性.最后通过实验测试证明了,关节力敏感度能有效度量关节对交互力的敏感性,末端执行器的位置和姿态能直接改变关节力敏感度.

The security of human-robot interaction for a Stewart parallel manipulator is studied. Firstly, a static model of the manipulator is developed, the force sensitivity and force sensitive direction of joint are proposed to evaluate the perception of joints for operating force, and the analytical method and the numerical method are combined to calculate the global joint force sensitivity. Secondly, the distributions of joint force sensitivity in Cartesian workspace and orientation workspace are analyzed, and the influence of configuration parameters on the global and local force sensitivities is given. The security of human-robot interaction can be increased by improving the joint force sensitivity through some measures, such as constraining the workspace, adjusting the position and orientation at work, and choosing feasible configuration parameters at the design stage. Finally, experimental tests show that the joint force sensitivity is an effective index for evaluating the joint sensitivity for interaction forces, and the changes of position and orientation of the end effector can affect joint force sensitivity directly.