A robust gyroless attitude estimation scheme for a small fixed-wing unmanned aerial vehicle

This paper proposes a backup attitude estimation scheme for small fixed-wing unmanned aerial vehicles (UAVs) in the event of gyroscopic failure. The attitude of the system is propagated in terms of 3 degrees-of-freedom (DoF) aircraft dynamics while a combined accelerometer and global positioning system (GPS) based attitude measurement scheme is used to update attitude errors. The uncertainties in the aircraft dynamics are modeled as norm-bound uncertainties and a discrete-time robust extended Kalman filter (REKF) is implemented to estimate the attitude of the UAV.