Object-transportation control by multiple wheeled vehicle-planar Cartesian manipulator systems

This paper proposes a control scheme to transport a palletized load by several wheeled vehicles (automated guided vehicles in factory). The planar Cartesian manipulator with two-degrees-of-freedom prismatic joint and one-degree-of-freedom rotary joint is mounted on each vehicle so that the vehicle with nonholonomic constraint and slow dynamic response can dexterously manipulate the pallet. Each vehicle-manipulator system independently controls the acceleration of its own hand grasping the pallet based on the prescribed mechanical impedance model. The kinematical redundancy of the vehicle-manipulator system is exploited to keep the manipulator arm within its workspace while executing the hand desired acceleration faithfully. The simulation result for the object-transportation by four vehicle-manipulator systems illustrates the validity of the proposed control scheme.