Managing Sensor Hardware Redundancy on a Small Commercial Aircraft with H-infinity FDI Observers

In this paper the problem of managing Hardware redundancy on theAttitude Heading System and the Air Data System of a smallcommercial aircraft is considered. The proposed approach is basedon a bank of extended H-infinity observers guaranteeing sensorfault detection and isolation in the presence of externaldisturbances and model uncertainties. Each observer is composedof an open loop nonlinear part replicating the system dynamics anda linear feedback action. Sufficient conditions for the synthesisof the feedback action are provided in terms of an LMI feasibilityproblem. Constraints on the position of the observer poles areadded to fasten the residual generation dynamics and to avoid lowdamped and/or high frequency modes. Numerical simulations on themodel of the AP-68 Vulcanair small commercial aircraft arepresented.