Abstract The application of hybrid mechanisms in the field of humanoid robots has attracted significant attention. A novel eight-degree-of-freedom hybrid manipulator is proposed to realize a kinematic function similar to that of the human arm. A general method for solving the inverse displacement problem of hybrid mechanisms is given, and the proposed humanoid robotic arm is taken as an example to demonstrate the solution process of this method. Furthermore, a closed-form solution for the inverse displacement problem of the hybrid humanoid robotic arm is derived by using the given method based on screw theory, exponential product formula, and Paden–Kahan subproblems. In addition, the problem of verifying and selecting the appropriate solutions according to the starting postures is also illustrated in a series of simulation experiments. Simulation experiment results show that there are (at most) 32 sets of solutions for the proposed humanoid robotic arm according to the same target position-orientation matrix and the given redundant input variables, and the accuracy of the proposed method for solving the inverse displacement problem is verified.

中文翻译：

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一种新型混合仿人机械臂的反位移分析

摘要 混合机构在仿人机器人领域的应用引起了广泛关注。提出了一种新颖的八自由度混合机械手，以实现类似于人类手臂的运动学功能。给出了求解混合机构逆向位移问题的一般方法，并以拟人机器人手臂为例说明了该方法的求解过程。此外，通过使用基于螺旋理论、指数乘积公式和 Paden-Kahan 子问题的给定方法，推导出了混合人形机械臂逆位移问题的封闭形式解。此外，在一系列仿真实验中还说明了根据启动姿势验证和选择合适解决方案的问题。