Effective Rigidity of Robot Structures: Analysis and Enhancement

Analysis of effective compliance breakdown between various structural subsystems as well as a novel concept of stiffness enhancement for robot manipulators are considered. Compliance breakdown shows a relatively insignificant role of linkage compliance (2-20% of the overall compliance depending on design) as well as domination of the break-down by one component. A combination link concept allows to reduce end-of-arm displacement as well as necessary driving torque, and increase structural natural frequency. Optimization of the combination link is performed for various combinations of joint-link compliances as well as for various preloads.