Cooperative Control of Mobile Manipulators Transporting an Object based on an Adaptive Backstepping Approach

Abstract

This paper proposes a new adaptive backstepping control scheme for the cooperative control of two mobile manipulators to transport a common object which is rigidly attached to their end-effectors. The key idea is to provide simultaneous control of the mobile base and the end-effector. A two-stage controller is proposed where kinematic backstepping is applied to control the velocity of the mobile platform and adaptive torque control is designed for the end-effector motion tracking. Model parameters are assumed to be completely unknown and are estimated using the adaptive law. Damped Least Squares (DLS) method is used to update the model parameters. The simulation results for two mobile manipulators validate the effectiveness of the proposed controller.