Nonlinear H_infinity Control Via Quasi-LPV Representation and Game Theory for Wheeled Mobile Robots

In this paper, nonlinear dynamic equations of a wheeled mobile robot (WMR) are described in the state-space form where the parameters are part of the state (angular velocities of the wheels). This representation, known as quasi-linear parameter varying (quasi-LPV), is useful for control designs based on nonlinear H_infin approaches. Two nonlinear H_infin controllers that guarantee induced L₂-norm, between input (disturbances) and output signals, bounded by an attenuation level gamma are used to control a WMR. These controllers are solved via linear matrix inequalities (LMIs) and algebraic Riccati equation. Results in simulation are presented, with a comparison study of these two robust control strategies and the standard computed torque, plus proportional-derivative, controller