Fault-Tolerant Control for Uncertain Sub-Fully Actuated Systems

This paper presents a fault-tolerant stabilization method for a class of uncertain high-order sub-fully actuated systems (sub-FASs) with actuator faults. As one of the important branches of the fully actuated system theory, sub-FAS control is more sophisticated and challenging due to the singularity problem. To deal with the fault tolerance issue of uncertain sub-FASs, a high-order nonlinear system model with both multiplicative and additive actuator faults is introduced. Motivated by the idea of FAS approach, a robust adaptive tracking controller is proposed to make system states track specific reference signals and avoid singularity under certain feasibility constraints. Then, a sufficient condition to ensure the feasibility constraints are satisfied is further derived. By appropriately selecting reference signals, the faulty sub-FAS is ultimately uniformly bounded. Finally, a numerical example is given to illustrate the effectiveness of the proposed method.