Trajectory tracking problem for a Flexible Mobile Manipulator: A Flatness Based Approach combined with Active Disturbance Rejection Control

Abstract

This article proposes a suitable combination of Differential Flatness and Active Disturbance Rejection Control (ADRC) for the trajectory tracking problem on a flexible link mobile manipulator. The robot is composed of a flexible link (appendage) mounted on a cart and actuated at its base. A simplified virtual rigid link model, equipped with a rotational joint flexibility at the base, is proposed for modeling the nonlinear dynamics. The proposed model allows, quite realistically, to develop a robust controller on the closed loop behavior of the system. A finite element software (FEM software) is used to validate the proposed approach which simulates the dynamics of the real system. The robustness and effectiveness of the proposed control method is tested via realistic computer simulations with the FEM software, using physical parameters values obtained from an actual experimental platform. The obtained results are quite satisfactory in spite of un-modeled disturbances. Experiments, which are currently under way on an laboratory platform, will be reported elsewhere.