钢丝绳传动机器人运动学的回路分析方法

Loop Analysis Method for Kinematics of Steel Cable-driven Robot

研究分析了一类2N条钢丝绳驱动N个自由度机器人的运动学,其运动学分析可通过推导除去钢丝绳后的开环链机器人关节角位移与末端执行器之间的运动学模型和关节角位移与电机转子角位移之间的运动学模型两个步骤完成。在运动学分析的基础上,提出了用回路矩阵和等效半径矩阵描述钢丝绳传动机器人运动学的回路分析方法。根据钢丝绳传动原理,通过观察法可直接列写回路矩阵和电机驱动空间等效半径矩阵,从而得到电机转子角位移与关节角位移之间的映射关系模型,解耦了由于钢丝绳传动导致机器人关节之间的运动耦合。实现了电机驱动空间、关节空间和笛卡尔空间之间完整的运动学映射,加快和简化了钢丝绳传动机器人运动学的建模和分析过程。最后,以Utah/MIT手指为例进行了运动学分析,比较Matlab运算和Solidworks Motion仿真的末端运动轨迹,验证了回路分析方法的正确性。

Kinematics of a kind of N degrees of freedom robot driven by 2N steel cables was studied in this paper. The kinematic analysis was accomplished by two steps, the first one is the derivation of kinematic models between the joint angle displacement and the end-effector of open-loop chain robots, and the second one is the kinematic model describing the relationship between the joint angular displacement and the motor-rotor angular displacement. Loop analysis method using loop matrix and equivalent radius matrix representation for kinematics of steel cable- driven robots were proposed on the basis of kinematic analysis. Loop matrix and equivalent radius matrix in motor- driven space was built and the mapping relationship models was got by observation method according to the schematic of steel cable transmission, which realized the motion decoupling of the existing joints of steel cable- driven robots. The full kinematic mapping models among motor actuator space, joint space, Cartesian space were accomplished, which speeds up and simplifies the kinematic modeling and analysis process of steel cable-driven robot. Finally, the kinematic analysis of the Utah/MIT finger and the end-effector trajectories analysis were performed by using Matlab and SolidWorks, which validates the correctness of loop analysis method.