Active Fault-Tolerant Control System using Incremental Backstepping Approach

Abstract

This paper proposes an Active Fault-Tolerant Control System (AFTCS) using the Incremental Backstepping (IBS) approach. The AFTCS contains a sensor Fault Detection and Diagnosis (FDD) system and a Fault-Tolerant Control (FTC) system and it is able to cope with Inertial Measurement Unit (IMU) sensor and Air Data Sensors (ADS) faults, as well as actuator faults and process faults. IMU faults are detected and estimated by an Iterative Optimal Two-Stage Extended Kalman Filter whereas ADS faults are detected and diagnosed by designing an Iterative Three-Step Extended Kalman Filter. The FTC system uses an IBS controller in order to cope with actuator and process faults. The FDD system provides more reliable information for the FTC system which guarantees that the IBS can maintain the flight. The performance of the complete AFTCS is validated using a Cessna Citation II aircraft model with the objective of attitude control. The simulation results demonstrate that the AFTCS is able to maintain the flight in the presence of sensor and actuator faults.