A New Robust Control for Mobile Robots with Differential Wheels: Output- and State- Dependent Riccati Equation Approach

A new application of Output- and State- Dependent Riccati Equation (OSDRE) framework for robust control of over-actuated uncertain systems with constraints is addressed in this paper. Towards this aim, an equivalent optimal problem is introduced using OSDRE. The performance index for an auxiliary output- and state- dependent system is modified through inclusion uncertainty upper bounds and then minimized. The proposed method is employed for controller design of a mobile robot with differential wheels. Uncontrollability condition put on SDRE due to differential constraints of wheels. This problem leads to SDRE to be hardly solved. One could overcome this problem by a proper coordinate transformation. In this paper considering the capability of output feedback to remove outer layer of kinematic and direct control the output dynamics, this problem is handled. Simulation results for a mathematical model and a wheeled mobile robot easily demonstrate the efficiency and satisfactory performance of the proposed robust control scheme.