Transient management of a supervisory fault-tolerant control scheme based on dwell-time conditions
Résumé
The paper deals with the design of an active fault-tolerant control strategy based on the supervisory control approach technique for linear time invariant MIMO systems affected by disturbances, measurement noise, and faults. From a bank of Luenberger observers that plays the role of a fault detection and isolation scheme, the supervisory algorithm aims at selecting the suitable fault-tolerant controller by means of a hysteresis-based switching mechanism. Based on dwell-time conditions, Lyapunov global exponential stability is addressed, and it is shown how transient behaviors due to the inherent interactions between fault detection and isolation, fault-tolerant control, and the reconfiguration mechanism can be improved. The main advantage with respect to existing solutions of open literature is relative to a simple parameterization of all controllers (possibly having different state dimensions, integral action, and/or unstable poles) in order to cope with bumps and undesirable transients when (possible multiple) switches occur. Moreover, it is shown that it is possible to improve (reduce) the dwell-time value in some cases. The efficiency of the approach is demonstrated on the academic highly maneuverable technology benchmark.