A Cooperative Task with Vehicle and Arm in a Mobile Manipulator

This paper proposes position and force hybrid control of a mobile manipulator to cooperate with its subsystems which are a wheeled mobile robot and a manipulator arm. These subsystems have different dynamical characteristics. Moreover, a wheeled mobile robot is subject to nonholonomic constraints. In general, these issues are taken into consideration in developing a planning and control algorithm. This paper describes a unified approach to control a mobile manipulator which can regarded as a redundant manipulator. In the proposed approach, realizing the high manipulability of the end-effector's motion, the redundancy of the whole system is utilized under consideration of the dynamical behavior. Then equivalent mass matrix is introduced as a performance index of the end-effector's dynamical motion. The effectiveness of the proposed control methods is confirmed by several experimental results.