高集成三自由度解耦球型手腕

Highly integrated spherical wrist with decoupled three degrees of freedom

针对空间机器人手腕集成度低和灵活性差的问题,提出一种由相对独立运动链组成的三自由度解耦球型手腕机构,采用双万向节和双半球结构来保证腕关节的紧凑性与灵活性.分析运动传动关系和工作空间区域,完成三自由度解耦球型手腕的结构设计,推导正、逆运动学方程和雅克比矩阵,分析结构解耦和运动解耦特性,建立作业空间与关节空间的运动传递关系.构建三自由度解耦球型手腕试验平台,进行侧摆、俯仰、自转试验和末端运动轨迹验证试验.研究结果表明,解耦球型手腕运动灵活、平稳,姿态角调整范围大,轨迹跟踪准确.

To improve integration and flexibility of space robot wrist, a 3-DOF decoupled spherical wrist with independent kinematic chains was proposed. The structure of double universal joints and double hemi- spheres was employed to guarantee compactness and flexibility of the spherical wrist. The transmission re- lationship of three motions and the workspaee of the wrist were analyzed, the structure design of the 3- DOF decoupled spherical wrist was finished, the forward and inverse kinematics and Jacobian matrix of the spherical wrist were derived, the characteristics of motion decoupling and structure decoupling were inves- tigated, and the motion transitive relation between the working space and the joint space was established. The experimental platform of the 3-DOF deeoupled spherical wrist was established, the posture motion ex- periments of pitch, yaw and rotation were conducted, along with the verification experiment of motion trajectory of the wrist end. The study results show that the decoupled motions of the 3-DOF spherical wrist are flexible and smooth, posture angles can be adjusted in large range, and accurate trajectory track- ing can be realized.