QP-based refined manipulability-maximizing scheme for coordinated motion planning and control of physically constrained wheeled mobile redundant manipulators

By following the pseudoinverse-type formulation, a corresponding quadratic program (QP)-based rough manipulability-maximizing (RoMM) scheme is obtained. In consideration of the drawbacks of the RoMM scheme, a novel QP-based refined manipulability-maximizing (ReMM) scheme is proposed and investigated in this paper for coordinated motion planning and control of a physically constrained wheeled mobile redundant manipulator (WMRM). Such a scheme treats the mobile platform and the redundant manipulator as a combined robotic system, showing an interesting trend of combining motion planning and reactive control methodologically and systematically. In addition, physical limits of mobile manipulators are incorporated into the scheme formulation, which enables the proposed ReMM scheme to keep all the resolved variables within their physical limits. Besides, the proposed ReMM scheme is finally reformulated as a unified QP. For testing the ReMM scheme, the WMRM composed of a two-wheel-drive mobile platform and a six-degrees-of-freedom manipulator is presented and investigated, together with its kinematics analysis. Comparative simulations performed on such a WMRM substantiate the efficacy, accuracy and superiority of the proposed ReMM scheme, as compared to the RoMM scheme.