A novel sliding mode fault-tolerant control strategy for variable-mass quadrotor

In this article, we investigate a fault-tolerant control (FTC) for a class of quadrotors with variable mass and actuator faults. Firstly, a mathematical model of quadrotors considered variable-mass factor is established based on Euler Newton's formula. Secondly, an adaptive estimation algorithm based on a fault observer is designed to achieve the estimations of variable mass and actuator fault, respectively. With the aim of obtaining satisfactory trajectory tracking performance, utilizing the variable mass estimation, a nonsingular terminal sliding mode controller is designed to track desired position. Meanwhile, utilizing the information of actuator fault estimation, an integral sliding mode controller is designed to track desired attitude. Finally, by comparison with the existing sliding mode control (SMC) and other FTC algorithm, the results show that the proposed FTC method has better tracking performance in the case of variable mass, fault and disturbance.