Robust-flatness Controller Design for a Differentially Driven Wheeled Mobile Robot

Abstract

This paper addresses the problem of robust motion control of a Differentially Driven Wheeled Mobile Robot (DWMR). Using the fact that DWMRs are differentially flat systems, the motion control design is relatively simplified by defining the desired motions of the robot in the flat output space of the system. The accurate and the robust trajectories tracking are provided firstly, by imposing the sliding manifold from the flat output space of the system. Secondly, an adaptive gain discontinuous control law -adaptive sliding mode controller- is introduced to drive to zero in finite time such sliding manifold, despite model uncertainties and external disturbances. The system stability is proven using the Lyapunov theory. Compared with classical Feedback control algorithms and using the laboratory test prototype, Pioneer 3DX, simulation and practical tests are presented to illustrate the performances of the proposed approach in the presence of unknown external disturbances.