Dynamics of a modular manipulator with multiple actuation modes for space applications

A manipulator, designed with N double-tripod multi-loop modules, is the subject of this paper. Each module is configured with multiple actuation alternatives, thus offering both multiple operation modes and design possibilities, along with control challenges. In this paper, a dynamics model of the manipulator of interest is implemented via a novel procedure. The key issue lies in finding the relationship between various actuation modes, to establish one generic dynamics model suitable to all actuation modes. The twists of all moving rigid bodies of the manipulator are derived and represented in terms of general expressions, to be used in the subsequent analysis. A three-modular manipulator is employed to illustrate the implementation of the modeling procedure. Simulation results and prototype experiments of the same manipulator are reported, to validate the procedure. The dynamics analysis reported here is intended to support the subsequent actuation-mode optimization and design of the whole system.