A systematic approach to inverse kinematics of hybrid actuation robots

Abstract

Hybrid actuation robots are mechanisms that are driven by at least one constant velocity motor and one servo motor. Such a robot or mechanism has found a growing number of applications. In designing such a mechanism there is a need to perform inverse kinematics due to presence of the servo motor. Inverse kinematics of a hybrid actuation mechanism is significantly different from that of a mechanism that is driven by the servo motor only. In literature, there is a lack of a general approach to inverse kinematics for general hybrid actuation machines. Ad-hoc treatments of inverse kinematics are prone to error. In this paper, we present a general approach to inverse kinematics for hybrid actuation mechanisms. The approach is primarily based on the group technique. In particular, we propose a set of groups as well as their inverse kinematics. Then, a hybrid actuation mechanism is decomposed against these groups and inverse kinematics can then proceed in a way by assembling the inverse kinematics of these groups. Several examples are presented to show the effectiveness of this general approach.