Fixed-time integral-type sliding mode control for the quadrotor UAV attitude stabilization under actuator failures

In this work, two fixed-time fault-tolerant control schemes are developed to address the problem of attitude stabilization of a quadrotor unmanned aerial vehicle with external disturbances and actuator faults. By utilizing homogeneous approach, a nominal controller is first presented to ensure the fixed-time stability of the fault-free system. Then, a novel integral-type sliding mode and adaptive technique based fixed-time control law is proposed to restrain the disturbances and actuator faults. To further compensate the uncertainties and failures actively, a fixed-time observer based fixed-time fault-tolerant controller is proposed using the integral-type sliding mode control strategy as well. The proposed schemes are proved to be stable theoretically and strictly in the sense of Lyapunov. Finally, the fine performances and capabilities of the designed schemes are verified by numerical simulations.