Kinematic Analysis for a 7-DOF Modular Hybrid-Driven Manipulator

A hybrid-driven approach, consisting of cable-driven and convention-driven designs, for a 7-DOF manipulator, is proposed in this paper. This approach combines the merits of cable-driven parallel mechanism and modular serial structure, so that the workspace of the manipulator is larger than that of conventional cable-driven design. The paper first introduces the hybrid mechanism design of the manipulator whose shoulder joint is a modular serial structure. Then the forward kinematics of the manipulator is solved based on geometry analysis. Afterwards with analysis of relationship between cable length and joint angle, the velocity analysis and incremental displacement analysis are respectively employed to calculate the inverse kinematic solution. Finally, by utilizing VC++ software, a straight-line motion trajectory tracking for the hybrid cable-driven manipulator is realized, and the effectiveness of proposed approach has been verified by the simulation.