State/fault Estimation and Fault-tolerant Control by SOS approaches under Unmeasurable States

Abstract

This paper constructs a novel state/fault estimation (SFE) observer and integrated fault-tolerant controller for a series of tunnel diode circuits based on SOS approaches. The unmeasurable states are taken into consideration, expanding the application scope of the method, while a reduced-order observer is proposed to lighten the computational burden. The fault-tolerant control (FTC) unit is co-designed considering the estimation error, and a decoupling technique is employed to reduce computational complexity. For lower conservativeness, stable constraints ensuring the stability of the augmented system under H ∞ performance γ are given in the format of sum-of-squares (SOS). Finally, the validity of the proposed method is verified through a simulation experiment of a tunnel diode circuit.