五自由度机器人逆运动学解法与工作空间分析

Innovative closed-form solution and workspace analysis for a 5-DOF manipulator

针对一种五自由度机器人结构,提出了一种精确求解逆运动学的封闭解法,解决了逆运动学数值方法计算较慢、在某些情况不能算出所有可能解问题.应用D-H方法建立了该五自由度机器人的运动学模型.在此基础上,依据该机器人的特定构型,应用代数方法,仅选取位置矢量和一个姿态矢量提出了所研究机器人的逆运动学封闭解法.选取一个马鞍面做为该机器人打磨作业任务,分别进行了Matlab数值计算仿真和ADAMS虚拟样机联合仿真分析.结果显示:马鞍面期望轨迹和遍历轨迹对应的位置和姿态具有高度一致性,验证了所提出逆运动学封闭解法的正确性.最后,通过数值计算求解了该机器人的可达工作空间,为该机器人结构优化和运动控制提供依据.

An innovative closed-form solution was proposed to address the inverse kinematics for a 5 degree of freedom (DOF)manipulator.This closed-form solution could be solved the disadvantages of numerical methods (Numerical methods were slower than closed-form solutions and do not allow com-putation of all possible solutions in some cases).The kinematics of this manipulator was modeled based on the Denavit-Hartenberg method.Based on the particular geometric features of this manipula-tor,only one orientation vector and the position vector were selected to propose this innovative closed-form solution for the inverse kinematics.Additionally,a saddle surface was chosen in the kinematics simulation for the grinding task of this manipulator.The validity of the proposed closed-form solution is verified via Matlab numerical simulation and ADAMS virtual prototype simulation.The overall con-sistency of positions and orientations corresponding to the tool desired trajectory and the tool traversal trajectory can be found from the simulations.Finally,the reachable workspace of this manipulator is obtained for the further structure optimization and motion control.