Abstract:

Aiming at the altitude reducting control problem for unmanned powered parafoil in low-altitude with model uncertainties, an adaptive fuzzy backstepping control strategy based on variable-gain is proposed. Firstly, the backstepping law of the parafoil trailing edge deflection based on variable-gain is derived under a stable velocity and the controller form is simplified by designing gain parameters. Secondly, the fuzzy logic systems (FLS) are employed to approximate model uncertainties and the adaptive robust item is used to eliminate the approximation errors. Both FLS strength and adaptive laws obtained through the Lyapunov stability theorem are adopted to guarantee the uniformly ultimately bounded of the closed-loop system. Finally, for the combination of the controller gain, the gain parameters are adjusted online by using the single fuzzy system. The simulation results verify the effectiveness of the proposed method.