Fault tolerant control design via the adaptive two-stage LQ reliable control

This paper presents a new fault tolerant control based on LQ design method that may stabilize a given system both in the nominal situation, as well as in the situation where some of the actuators have failed. This new control result basically follows the design guideline of the recently developed adaptive two-stage LQ reliable control (ATSLQRC), and considers the faults not confined to a preselect set of actuators. The unified gain margin constraint of the ATSLQRC is presented. It is also shown that the ATSLQRC serves as a guaranteed cost control provided that its design parameters satisfy two new proposed guaranteed cost gain margin constraints. A numerical example is given to illustrate the effectiveness of the proposed results. A potential application of the proposed results to design a passive fault tolerant control is also addressed.