闭环双驱动混合输出六自由度并联机构运动分析

提出一种分支含闭环双驱动单元、可实现混合输出的六自由度并联机构。分析了动平台混合运动时驱动分支的等效形式，以及独立位姿运动和振动时驱动分支的等效形式;分析了混合运动关于位姿运动输入和振动输入的位置反解，对振动输入的位置反解设计了基于机构运动特点的逐次逼近法；运用螺旋理论求得动平台混合运动时关于全体12个独立广义坐标的一、二阶影响系数，得到从广义输入到动平台旋量速度、加速度的线性映射；通过数值算例分别对位姿运动输入和振动输入的理论分析结果进行了验证,算例仿真表明,提出的两种双驱动输入分配计算规则均能得到确定的混合运动输出。

Kinematic Analysis of a 6-DOF Parallel Mechanism with Closed Loop Dual-drive and Composite Output

A parallel  mechanism  that can accomplish 6 dimensional composite output was proposed,each leg of it had  a closed-loop dual-drive  unit.The equivalent  form  of  one  leg was analysed when the moving  platform was under composite motion,so  as the equivalent form of one leg corresponding to independent position and orientation motion and vibration.The inverse position solution about position and orientation drive and vibration drive  were analysed,for inverse position solution of vibration drive,a  kind of successive approximation  method was designed based on the motional features of mechanism.Using screw theory the first and second order influence  coefficients  of all the 12 general coordinates were obtained, so the linear mapping from general inputs to screw velocity and acceleration of moving platform was obtained.Theoretical analyses of position and orientation motion drive and vibration drive  were  verified by numerical examples,it is indicated by the numerical simulation that composite output can accomplish through the two rules presented for dual-drive distribution.