机械手臂正运动学及其末端机械手工作空间研究

Research on Forward Kinematics of Mechanical Arm and Workspace of Its End Robot Hand

机械手臂作为机器人实现抓取任务的主要执行机构,其合理化结构设计、运动学模型构建及可达空间问题一直是研究热点。基于机械手臂构型特点,采用改进的D-H法创建了机械手臂正运动学模型,通过齐次坐标变换推导出末端机械手的位置矩阵,并通过理论计算与仿真结果对比验证了所建模型的准确性;利用蒙特卡洛法对末端机械手工作空间进行模拟,得到末端机械手工作空间点云图及工作边界;利用convhull凸包函数处理边界点云,生成一个较为准确的包络空间进而计算该工作空间体积大小;在此基础上,进一步分析得到机械手臂结构参数对其工作空间体积的影响规律,为后续机械手臂结构参数优化、运动控制和轨迹规划等提供了参考。

As the main executive mechanism of the robot’s grasping task,the rational structure design and terminal reachable space of mechanical arm are always the research hotspots.The forward kinematics model of the mechanical arm was created by using the improved D-H method according to the configuration characteristics of the mechanical arm,and the accuracy of the model was verified by comparing the numerical calculation and simulation results.The working space of the end robot hand was analyzed by using Monte Carlo method,and the working points cloud map and working boundary of the end robot hand were obtained.The convhull function was used to deal with the boundary point cloud,and the envelope space was generated to solve the workspace volume.On this basis,the influence law of the structure parameters of the mechanical arm on the workspace volume was further analyzed.It provides reference for the optimization of the structure parameters,motion control and trajectory planning of the mechanical arm.