Disturbance observer-based fault-tolerant control of UAV with obstacle avoidance

This paper studies the fault-tolerant control (FTC) of fixed-wing unmanned aerial vehicle (UAV) with obstacle avoidance. Firstly, the path planning of the UAV is realized by improving the traditional artificial potential field (APF) method to achieve obstacle avoidance. The improved APF method solves the unreachable target and local minimum problems existing in the traditional APF. Secondly, the lumped uncertainty composed of the thrust fault, external disturbances and parameter inaccuracies is estimated by the nonlinear disturbance observer. In addition, an FTC scheme based on nonsingular fast terminal sliding mode (NFTSM) is proposed for UAV under thrust fault. Finally, simulation is used to confirm that the design plan is proper.