A hybrid teleoperation control scheme for a single-arm mobile manipulator with omnidirectional wheels

In this paper, an hybrid position-position and position-velocity teleoperation control scheme for a generic mobile manipulator is presented and discussed. The mobile manipulator is composed by a mobile platform and a 5 dof arm, and the proposed control scheme allows the simultaneous control of both the devices by means of a single haptic device characterized by an open kinematic chain and not specifically designed for mobile manipulators teleoperation (e.g. a Phantom Omni). The proposed teleoperation controller overcomes the mismatch of the control signals to be sent to the arm (position) and to the mobile platform (velocity) through a proper partition of the master device workspace. Tests have been performed both by simulation and with a real setup. The setup is composed by a 6 dof Phantom Omni haptic device acting as master, and a single-arm Kuka youBot omnidirectional manipulator acting as slave. Experimental results related to a pick and place task, performed on the real setup and involving the motion of both the arm and the platform are reported and commented.