Cooperative Motion Control by Human and Mobile Manipulator Using Equivalent Mass Matrix and Virtual Impedance

This paper aims at the improvement in a future life using a mobile manipulator. For example, power assistance of old people and cooperative operation with human. For coexistence of robot and human being, it is required that a person can work in cooperation with robot safely. To address this issue, this paper introduces interactive virtual impedance which determines the cooperative motion between robot and human being. The external force by human added to end-effector of manipulator is given into vehicle and manipulator as force command. The equivalent mass of each system is used as a standard which opts for operation of manipulator and vehicle. By determining the impedance input of the vehicle according to equivalent mass, the virtual force input to the vehicle in consideration of the manipulability of manipulator and vehicle can be performed. This is one of the remarkable points in the proposed strategy. The validity of the proposed method was confirmed by numerical simulation and experimental results.