Failure detection and identification and fault tolerant control using the IMM-KF with applications to the Eagle-Eye UAV

We describe a novel approach to sensor/actuator failure detection and identification and fault tolerant control based on the interacting multiple model (IMM) Kalman filter approach. Failures are mapped into different (and unique) state-space model representations. The IMM algorithm computes (online) the posterior probability of each failure model, that can be interpreted as a failure indicator. The fault tolerant control approach presented is based on a multiple model control law, where an optimal controller is designed for each actuator failure model, and the control action is a combination of the individual outputs of each controller weighted by the posterior probability associated with that model. The new FDI-FTC approach was tested on a linear simulation of Bell Helicopter´s Eagle-Eye unmanned air vehicle. All single sensor and actuator failures were detected and properly identified, as well as some simultaneous failures