Fractional-order Nonsingular Fast Terminal Sliding Mode Control for Quadrotor with Uncertainties and Input Saturation

This paper mainly studies the trajectory tracking of an uncertain quadrotor dynamic system with control input saturation. First, a nonlinear dynamics model of quadrotor is established based on Euler-Lagrangian method, and some basic theories of fractional-order calculus are introduced; then, a fractional-order terminal sliding mode control method (FO-TSMC) is designed for the quadrotor’s position subsystem, a new fractional-order nonsingular fast terminal sliding mode control method (FO-NFTSMC) is designed for the attitude subsystem. In addition, we consider constructing an auxiliary system based on the hyperbolic tangent function to solve the problem of control input saturation. Finally, the Lyapunov function is used to prove the asymptotic stability of the closed-loop control system. The numerical simulation results of DJI M100 aircraft show that the controller designed in this paper is effective.