Non-fragile Robust Passive Control For Uncertain Fractional Order Systems

Non-fragile control refers to the capacity of a closed-loop system to preserve its inherent characteristics under a designed fixed-parameter controller,even in the presence of certain perturbations in the controller parameters.Such a system does not experience substantial changes due to minor fluctuations in the controller’s internal parameters.In non-fragile control,the controller design must accommodate external disturbances and uncertainties,ensuring that the system maintains effective control when influenced by these factors.Although non-fragile passive control of integer-order systems has been extensively implemented,research on non-fragile control of fractional-order systems remains relatively limited.Consequently,this thesis aims to address the non-fragile passive control issue of fractional-order systems.The present study investigates the non-fragile passive control problem for uncertain time-delay fractional-order systems and a specific class of nonlinear fractional-order singular systems.Firstly,the robust passive control issue for uncertain time-delay fractionalorder systems is explored.Subsequently,a sufficient condition for the closed-loop system’s passivity under the non-fragile state feedback controller is established,and an observerbased state feedback controller design approach is introduced,using linear matrix inequality techniques.Secondly,the robust passive control problem for a certain class of nonlinear fractional-order singular systems is examined.A non-fragile state feedback controller is developed to ensure the closed-loop system’s robust passivity,and an observer-based nonfragile state feedback controller design methodology is proposed to preserve the closed-loop system’s robust passivity.Finally,the feasibility of the proposed methods is demonstrated through numerical examples.