Event-Triggered Diagnostic Observer Design Using the Performance Tradeoff Approach

This paper presents an optimal diagnostic observer design scheme to deal with the remote fault detection problem for a local closed-loop system with unknown external disturbances and faults. To utilize limited network shared resources efficiently, an event-triggered generator is employed in the local closed-loop system to determine whether to transmit the current output measurement for fault detection. By constructing the error system that contains event-triggered transmission errors and evaluating the composition of the residual under the constraint of Luenberger conditions, the diagnostic observer which has optional order and flexible structure is designed by the use of factorization techniques to achieve the optimal performance tradeoff between disturbance robustness and fault sensitivity. Next, the inevitable influence of reference input on the residual is taken into account in the residual evaluation to deliver a time-varying threshold. Finally, a vehicle lateral dynamic system is presented to illustrate the validity of the proposed optimal diagnostic observer design scheme.