基于四元数表示法的并联机构姿态奇异研究

基于单位四元数表示并联机构动平台的姿态,推导出当6/6-SPS 型Stewart并联机构动平台处于固定位置时机构姿态奇异轨迹的解析表达式,并通过计算机仿真给出姿态奇异轨迹的三维可视化描述.还探讨了机构动平台的几何外形、动平台和定平台的外接圆半径比、动平台的位置对机构姿态能力的影响.对机构姿态能力的研究为Stewart并联机构的优化设计提供了理论依据.

Orientation-Singularity Analysis of Parallel Manipulators Using Quaternion Representation

Based on the unit quaternion representation of orientations of the 6/6-SPS Stewart manipulator,an analytical expression that represents the orientation-singularity locus of the manipulator at a fixed position is derived and examples are given to illustrate the result.The paper also addresses effects of different geometry configurations of the moving platform,different ratios of the moving platform to the base one and different positions of the moving platform on the orientation capability of the 6/6-SPS Stewart manipulator.The conclusion presented in this paper provides underlying theoretical grounds for the optimum design of the 6/6-SPS Stewart manipulator.