摘要
构造退化条件数和容错空间影响因子两个容错性能指标,前者反映了某一故障时刻退化机器人的操作能力,后者反映了该故障时刻退化机器人相对工作空间的大小,它们可分别用来衡量机器人在故障时刻和故障后的容错操作能力。基于这两个指标,提出冗余度机器人结构参数的最优设计方法,该方法可以用来确定使机器人具有最佳容错操作性能的臂长参数。给出平面3R和空间4R机器人的仿真实例,并就容错操作性能对各臂长的敏感度进行了分析。研究结果表明,机器人的容错操作性能对不与故障关节相连或只与一个故障关节相连的臂长具有较高的敏感度,在调节臂长时,应优先考虑这些臂长。另外,与平面机器人不同,空间机器人的这两个容错指标并不存在着很有规律的对应关系,相互的冲突也不那么明显,这说明使他们同步最优的可能性更大。
Two fault tolerant performance indexes, reduced condition number and influence factor of fault tolerant workspace are introduced. The former indicates the manipulability of a reduced robot at the moment of a failure. The latter indicates the relative workspace of the reduced robot at this moment. These indexes can quantitatively evaluate the fault tolerant ability of a robot at the moment of a failure and after the failure respectively. Then based on these indexes an optimization method of structural parameters is proposed, which can determine the link length with optimal fault tolerance for a robot. Finally, simulation examples are demonstrated and the sensitivity of fault tolerance of a robot to each link is analyzed with a planar 3R and a spatial 4R robot respectively. The results show that the fault tolerant ability of a robot is more sensitive to the link that is not directly connected with any failed Joint or is connected with only one failed joint, which means that these links should be considered in the first place when adjusting link length. In addition, for spatial robots the corresponding relation between the two indexes is not as regular as planar robots, and the conflict between them is not obvious. This implies that it is more possible for spatial robots to simultaneously optimize these two indexes.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2007年第10期82-88,共7页
Journal of Mechanical Engineering
基金
北京市自然科学(3042005)。
关键词
冗余度机器人
容错性能
结构综合
Redundant robots Fault tolerant performance Structure synthesis
