Optimal Auxiliary Signal Design for a Lumped Tire-Road Friction System

Active fault detection consists of finding an auxiliary input signal the use of which allows detection of the masked faults using a multi-model framework in continuous or discretetime cases. In this paper, a modified approach to optimal auxiliary signal design in robust fault detection based on a multi-model formulation of healthy and faulty systems is used to study the problem of active fault detection for a class of systems with nonlinear coupled continuous state-space equations in the presence of uncertainties and disturbances. Due to the nonlinearity in the state-space equations, the traditional active fault detection approach is not straightforward to be employed. To overcome this difficulty, a modified solution is proposed in order to design an optimal auxiliary signal to guarantee robust fault detection for this class of nonlinear systems in the presence of uncertainties and disturbances. Finally, the proposed solution for optimal auxiliary signal design is applied to a Lumped Tire-Road Friction system.