关键词: 并联机构, 摩擦, 动力学, 四自由度

Abstract:

The primary goal of this research is to do dynamics analysis of a spatial parallel manipulator of four DOF under condition where the friction of
the driver was considered.A complete description of the position and orientation of the moving platform with respect to the reference frame requires four variables.Firstly,
closed form solutions to the input and output were built based on movement
characteristics,and then dynamics equations were built based on Newton-Euler formulation.Then based on three different friction model and cubic polynomial being used for motion planning, for a given motion,the constraining straining forces of each pair and driving
forces of each limp were deduced.The results demonstrate that the friction has obvious
influence on the driving forces.The calculation results show the friction's
impact on driving forces and constraining forces.

Key words: parallel mechanism, friction, dynamics, four degrees-of-freedom(DOF)