摘要
明确给出了并联机构的内力定义,并对非冗余机构非奇异位置、非冗余机构奇异位置和冗余机构三种情况的内力状况分别进行了说明。对于冗余并联机构的内力问题,给出了内力空间的维数和基底,指出了每种内力状态都是内力空间中的一个元素。以该定义为基础,文章给出了可用内力空间的范围及其判别条件。还分析了采用内力的方法来消除铰链间隙,提高运动精度的措施。以一种冗余Stewart机构为例,考察了内力改变机构刚度的效果,发现内力对这种机构刚性的改变作用很有限。这些结论为冗余并联机构的运动控制以及靠冗余驱动提高机构性能提供参考。
Explicit definition of internal forces in parallel mechanisms was proposed. The distribution of this kind of forces in singular and non-singular configurations of normal parallel mechanism, redundant parallel mechanisms was discussed, For redundant manipulators, the dimension and basis elements of internal-force-space （IFS） were given. Every kind of internal force state was an element in the IFS. Based on this definition, the usable IFS and its discriminant were established. Removing joint clearance and improving motion accuracy were another utilization of internal forces. For a redundant Stewart mechanism, the stiffness modification due to internal forces was carried out and it showed that this change was very limited. The results will be useful for motion control of redundant parallel mechanisms and improving gross performance of parallel manipulators.
出处
《机械设计与研究》
CSCD
北大核心
2006年第4期13-16,共4页
Machine Design And Research
基金
国家自然科学基金资助项目(50375010)
关键词
并联机构
冗余
内力
铰链间隙
刚度
parallel mechanism
redundant
internal force
joint clearance
stiffness
