Integrated identification and accommodation of sensor faults in networked distributed processes with communication delays

This paper considers the problem of sensor fault-tolerant control of a class of spatially distributed systems subject to discrete and delayed sensor-controller communication. An integrated approach that combines data-based fault identification and stability-based fault accommodation is developed on the basis of a suitable reduced-order model of the infinite-dimensional system. A moving-horizon parameter estimation scheme is developed to estimate on-line the size and location of the faults using the sampled output and input data. Once the location and magnitude of the fault are identified and communicated to the controller, fault accommodation takes place by means of adjusting the controller and estimator design parameters, and/or adjusting the control actuator locations. The selection of the appropriate strategy is made based on the estimated fault size and the characterization of the networked closed-loop stability region. The results are illustrated using a simulated diffusion-reaction process example.