FLATNESS-BASED FAULT TOLERANT CONTROL OF A NONLINEAR MIMO SYSTEM USING ALGEBRAIC DERIVATIVE ESTIMATION

A flatness-based approach to fault tolerant control is proposed. The approach uses the recently published algebraic derivative estimation method for the estimation of those output derivatives that are necessary for determining intermittent actuator faults. The rapid performance of the estimation allows for an accommodation of the control to the fault. Additionally, taking into account the control saturations a novel classification scheme for actuator faults is introduced that exhibits a comprehensible graphical representation in terms of reachable sets. Dependent on the respective class of fault, an online adaptation of the reference trajectory is carried out. The ideas are demonstrated on a nonlinear MIMO system, which corresponds to an underactuated rigid body.