基于肘部自运动的主从异构7自由度机械臂运动映射及其几何逆解

Master-slave 7-DOF Manipulator Motion Mapping Based on Elbow Self-motion and Its Analytical Geometric Inverse Kinematics

为了在异构遥操作系统中将主臂运动信息完整的映射到从臂,以人臂运动特性为依据,针对7自由度机器人提出了一种新的主从运动学映射方法。该方法以机器人末端位姿和自转角为基础,建立主从映射矩阵。提出关节融合策略,对因有偏置而无法汇交成肩肘腕点的机器人进行关节融合,从而形成等效肩肘腕点,并以此确定映射矩阵参数。建立参考坐标系,对遥操作过程中产生的基系漂移误差进行修正。针对肘或腕不汇交的7自由度机器人,提出了一种新的逆运动学求解方法。该方法利用几何关系求解等效肩肘腕点的位置,并依据各等效点与各关节点之间的关系求解各关节角。仿真和试验结果证明了所提出的映射方法能够使从臂按照主臂所提供的信息在等比例模型中完成运动,并且在运动过程中从臂自转角与主臂相同,完成避障任务。

In order to completely map the motion information of the master arm to the slave arm in the heterogeneous teleoperation system, a new kinematics mapping method for seven degrees of freedom(DOF) robot was proposed based on the motion characteristics of the human arm. This method establishes master-slave mapping matrix based on the pose of the robot’s end effector. A joint fusion strategy is proposed to perform joint fusion on a robot that cannot be merged into a shoulder and elbow wrist point due to offset, thereby forming an equivalent shoulder, elbow, wrist point, and determine the parameters of the mapping matrix. A reference coordinate system is established to correct the base drift error generated during teleoperation. A new inverse kinematics method is proposed for a 7-DOF robot with elbow or wrist not meeting. The method uses geometric relations to solve the position of the equivalent shoulder and elbow wrist points, and solves the joint angles according to the relationship between each equivalent point and each joint point. The simulation and experimental results show that the proposed mapping method can make the slave arm complete the motion in the proportional model according to the information provided by the main arm, and at the same time, the arm rotation angle is the same as that of the main arm during the motion, and the obstacle avoidance task is completed.