5-CS空间刚体导引机构缺陷判定  

Defect Judgment of 5-CS Rigid-body Guidance Mechanism

作　　者：胡俊杰[1] 韩建友[1] 崔光珍[1] 

机构地区：[1]北京科技大学机械工程学院,北京100083

出　　处：《农业机械学报》2016年第12期398-407,415,共11页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家自然科学基金项目(51275034)

摘　　要：提出了一种能实现空间刚体导引的5-CS空间并联机构,并给出了综合该类机构时运动缺陷的判定方法。首先使用旋量理论推导5-CS机构完整雅可比矩阵的计算公式,并计算机构在给定位置的雅可比矩阵行列式的值,如果各位置的雅可比矩阵行列式值的符号发生变化则机构存在缺陷,如果没有发生变化则应用牛顿迭代法对各给定位置区间进行机构的位置正解分析,以确定在区间内是否存在分支缺陷和回路缺陷。运动缺陷判定过程中会对机构在给定的位置区间内运动过程中完整雅可比矩阵的变化情况进行分析,如果存在完整雅可比矩阵行列式为零的位置(即奇异位形),则机构存在分支缺陷,如果给定位置在不同回路中,则机构存在回路缺陷。运动缺陷判定是机构综合能顺利进行的方法基础。本文还提出了双驱动控制方法以解决机构的分支缺陷问题。最后举例说明了5-CS机构的运动缺陷判定过程。A 5 - CS rigid-body guidance linkage was proposed. A method to judge the defects of 5 - CS linkage was proposed to solve the problems of defect judgment met in the process of rigid-body guidance design. Through calculating the Jacobian matrix＇ s determinant values of the given positions, it can be found out whether the signs of determinant values were changed at the given positions. If the signs were changed , the linkage had defects. If not, a curve tracking technique which based on Newton method was used to get the forward position solutions and then calculate the Jacobian matrix＇ s determinant values of the positions between the given positions. Based on the calculations, we can know whether there were positions which determinant values are zeros between the given positions. When the Jacobian matrix＇ s determinant value was zero, the linkage＇ s singular configuration occurred. According to the trajectory, we can clearly know whether the linkage has circuits or order defects. For solving the branch defect, the method of drives combinations was proposed. When the parameters of the linkage at a position were given, different Jacobian matrix＇ s determinant values can be got by selecting different drivers. So the branch defects can be avoided by changing the drive before the singular positions. Finally, a synthesis example was provided to illustrate the defect judgment process of 5 - CS linkage.

关 键 词：5-CS机构 位置正解 雅可比矩阵 缺陷判定 

分 类 号：TH112.1[机械工程—机械设计及理论]