Structure Synthesis Based on Fault Tolerant Performance Index for Spatial 4R Redundant Robots

To enlarge the fault tolerant workspace when robot's fault joint is locked,and improve the fault tolerant performance index,this paper used the influence factor as the fault tolerant index to conduct structure synthesis.Then,based on this index an optimization method of structural parameters is proposed,which can determine the link length with optimal fault tolerance for a robot.Simulation examples for a spatial 4R robots are given.