School of Mechanical Engineering, Yanshan University, Qinhuangdao 066004, China.
Parallel Robot and Mechatronic System Laboratory of Hebei Province, Yanshan University, Qinhuangdao 066004, China.
Sensors (Basel). 2021 Oct 31;21(21):7257. doi: 10.3390/s21217257.
A new method of kinematic analysis and singularity analysis is proposed for a 7-DOF redundant manipulator with three consecutive parallel axes. First, the redundancy angle is described according to the self-motion characteristics of the manipulator, the position and orientation of the end-effector are separated, and the inverse kinematics of this manipulator is analyzed by geometric methods with the redundancy angle as a constraint. Then, the Jacobian matrix is established to derive the conditions for the kinematic singularities of the robotic arm by using the primitive matrix method and the block matrix method. Then, the kinematic singularities conditions in the joint space are mapped to the Cartesian space, and the singular configuration is described using the end poses and redundancy angles of the robotic arm, and a singularity avoidance method based on the redundancy angles and end pose is proposed. Finally, the correctness and feasibility of the inverse kinematics algorithm and the singularity avoidance method are verified by simulation examples.
针对一种具有三个连续平行轴的 7 自由度冗余机械手，提出了一种新的运动学分析和奇异性分析方法。首先，根据机械手的自运动特性描述冗余角，分离末端执行器的位置和姿态，通过几何方法以冗余角为约束分析该机械手的逆运动学。然后，利用原始矩阵法和块矩阵法建立雅可比矩阵，推导出机器人手臂运动奇异的条件。然后，将关节空间中的运动奇异条件映射到笛卡尔空间，用机器人手臂的末端姿态和冗余角来描述奇异构型，并提出一种基于冗余角和末端姿态的奇异规避方法。最后，通过仿真示例验证了逆运动学算法和奇异规避方法的正确性和可行性。
