Fault detection isolation and reconfiguration algorithms for atmospheric re-entry

This paper proposes a new Fault Tolerant Control Strategy relying on Fault Detection, Isolation and Reconfiguration (FDIR) algorithms. Adaptive Control laws are combined to Control Allocation algorithms that enable the reconfiguration of Flight Control Laws in case of actuators and/or Reaction Control System (RCS) failures. This allows achieving good robustness to possible failures occurring during flight and, at the same time, to optimize the use of a hybrid set of control effectors (i.e. aerodynamic surfaces and Reaction Control System) such to reduce thrusters fuel consumption. Fault Detection and Isolation (FDI) algorithms provide the required information about the health status of actuators/RCS thus enabling the reconfiguration of Flight Control Laws. The effectiveness of the proposed approach has been preliminarily demonstrated through a numerical analysis that accounts for both nominal and failures scenario, by using a 6Dof Model of Flying Test Bed FTB3, developed by Italian Aerospace Research Centre in the framework of Unmanned Space Vehicle (USV) Program.