A Novel Hybrid Humanoid Dextrous Manipulator for On-Orbit Servicing and Its Kinematics Analysis

Humanoid dextrous manipulator as an important part of the space station manipulator system or robot astronaut is a significant research subject in the field of On-Orbit Servicing (OOS). Most of manipulators in International Space Station (ISS) have open kinematic chain and serially connected links which is weak on cumulative error, load capacity and motion inertia. In this work, a novel hybrid humanoid dextrous manipulator was proposed. It adopted 2-DOF spherical parallel manipulator (SPM) connected with two revolute pairs in series form as kinematic chains, that allow for increased load-to-weight ratio, speed, stiff-ness and dexterity. Closed-form solutions to the forward and in-verse position problems of this hybrid manipulator were presented. The theory of screws and lie group and lie algebra were applied to achieved the kinematics analyses, and the expressions of the velocity were investigated.