Force Control Application to a Mobile Manipulator with Balancing Mechanism

This paper presents control and implementation of the mobile manipulator with balancing mechanism whose goal is to serve human being in home environment. The mobile manipulator has two arms to handle objects. Not only position control but also force control of the balancing service robot is presented. The robot has two modes to move : mobile robot mode with 4 contact points and balancing mode of 2 contact points. The robot has two wheels to maintain balance and has the force control capability by using force sensor at the end-effector. Position based impedance force control method is utilized by filtering the force for the robot to have smooth reaction against disturbance induced by applied external force. Several experimental studies of contact force control, opening doors, and interacting with a human operator are demonstrated.