Non-fragile mixed event-triggered networked control for Takagi-Sugeno systems subject to actuator faults and external disturbances

This paper discusses the problem of non-fragile event-triggered networked controller design for Takagi-Sugeno (T-S) systems subject to actuator faults, external disturbances, and network-induced delays. To stabilize this class of Networked Control Systems (NCSs), a new Mixed Event Triggered Control (METC) control scheme, including memory data, is proposed to cope with actuator faults modeled as both additive and multiplicative terms acting as uncertainties in a non-fragile control law. Then, from a convenient choice of a Lyapunov-Krasovskii functional, together with appropriate relaxation techniques, providing boundedness conditions for actuator faults and assuming a prescribed H∞ disturbance attenuation level, relaxed LMI-based conditions are proposed to guarantee the non-fragile closed-loop NCS stability with METC. Two theorems are proposed. The first one deals with the NCSs stability analysis (i.e. assuming the controller's gains known), and the second one extends to their stabilization (i.e. the non-fragile controller design). Both these theorems allow the simultaneous design of the proposed METC condition. The proposed LMI-based conditions allow to further relax the admissible network-induced delay and event-triggered packet release intervals. Three simulation examples illustrate the effectiveness of the proposed METC design and highlight the conservatism improvements brought by this proposal with respect to previous related results from the literature.