Finite-time control for small-scale unmanned helicopter with disturbances

This work aims to develop finite-time stability property for trajectory tracking control system of small-scale unmanned helicopter subjected to uncertainties and external disturbances. The added power integrator method is applied to construct the nominal feedback control part, such that helicopters’ closed-loop system possesses highly tracking performance due to finite-time convergence property. In view of the existence of strong couplings, approximate feedback linearization is initially conducted to simplify and decouple helicopters’ input–output dynamics. Additionally, to guarantee robustness, the composite active disturbance rejection control idea is employed. These unknown perturbations are estimated using high-order sliding mode disturbance observers and compensated for directly in every virtual control law. Finite-time convergence property of the closed-loop system with disturbances is proven through Lyapunov stability theory. Finally, several comparison simulations illus-trate the effectiveness and superiority of our proposed methods.