基于3-RRP并联机构的腕关节设计与分析

针对球面3-RRP并联机构的理论分析不足以致运动学与动力学特性不明确的问题，设计了该构型的具体结构，分析了其运动学传递约束与驱动力矩特性。根据关于位置反解的Panda-Kahan理论，明确了灵活姿态空间与可达姿态空间的分布情况。基于旋量互易积，建立了关节的运动传递与约束能效系数。在此基础上，应用多参数平面模型技术，进一步揭示了参数尺度、姿态空间、性能指标之间的耦合关系，从而确定了参数取值，明晰了优质姿态空间范围和性能指标分布趋势。并基于虚功原理，建立了动力学模型，定性分析了驱动力矩特性。研究结果表明：该腕关节机构兼具机构紧凑、姿态空间大、完全的运动约束性能与优秀的运动传递性能、大负载重量比的特点，符合人体腕关节功能特性。

Design and Analysis of Wrist Joint Based on 3-RRP Parallel Mechanism

Aiming at the problem that the theoretical analysis of spherical 3-RRP parallel mechanism is insufficient, resulting in unclear kinematics and dynamic characteristics, the specific structure of the mechanism is designed, and the kinematic characteristics of transfer and constraint and driving torque characteristics are analysed. According to the Panda-Kahan theory about inversed position solution, the distribution of flexible and reachable orientation space are clarified. Based on the reciprocal product of screw vector, the transfer and constraint energy efficiency coefficients of joints are established. On this basis, the multi-parameter plane model technology is applied to further reveal the coupling relationship among parameter scale, orientation space and performance index. Thereby，the parameter value is determined, and the range of high-quality orientation space and the distribution trend of performance index are illustrated. Based on the principle of virtual work, the dynamic model is derived, and the driving torque characteristic is qualitatively analysed. The results show that the wrist mechanism takes into account the characteristics of compact structure, large posture space, complete constraint performance, excellent transfer performance, and high load-weight ratio, which is in line with the functional characteristics of human wrist.