基于牛顿欧拉法的3-RPS并联机构逆动力学分析

 以3-RPS机构为例，研究了对称少自由度并联机构的逆动力学问题。因其自由度数目小于6，该类机构的支链不仅传递驱动力，同时还需为动平台提供约束。然而，现有文献大多未对广义约束力给予足够的重视。采用牛顿欧拉法建立了3-RPS机构的刚体动力学方程，给定动平台的运动规律及外载荷后，可一并求解机构所需的驱动力与约束力矩。算例仿真表明，与动平台自由速度方向不一致的外载荷主要需由约束力矩平衡。因此，在对称少自由度并联机构动力学设计中，必须计入广义约束力的影响。

Inverse Dynamics of 3-RPS Parallel Mechanism by Newton-Euler Formulation

An analytical investigation is presented into the inverse dynamics of 3-RPS parallel mechanisms featuring symmetrical topology and limited degree-of-freedom(DOF).As the number of DOF is less than six,the limbs of a 3-RPS parallel mechanism must play the role of transmitting actuation and providing constraints simultaneously.However,insufficient attention has been paid to the generalized constraint forces in most literatures.By means of the Newton-Euler formulation,a novel rigid-body dynamic model is put forward for 3-RPS parallel mechanisms.The motion of moving platform and the working load being given,both the driving forces and the constraint torques may be calculated.The results of computational examples reveal that the working load,which is not parallel to the free velocity of the moving platform,is mainly balanced by the constraint torques.Therefore,the analysis of generalized constraint forces is necessary in the dynamic design of the limited-DOF parallel mechanisms with symmetrical topology.