Development of a Nonlinear Control Strategy for Quadrotors with Finite-Time Convergence Properties

Quadrotors are highly regarded for their exceptional maneuverability and unique capabilities. Numerous controllers, both linear and nonlinear, have been developed for quadrotor robots. The primary objective is to achieve finite-time control of a quadrotor. Considering the nonlinear dynamics of the system, a finite-time controller is designed using the terminal sliding mode method. This approach defines sliding variables based on finite-time control theory during the sliding phase. Additionally, for the reaching phase, a smooth reaching law—different from the conventional switching term in first-order sliding mode-is employed to generate a smooth control signal. Even with approximations in the boundary layer, the proposed reaching law results in less accuracy reduction compared to conventional methods. To control displacement in the x and y axes, a combination of backstepping and the proposed theories is utilized. The performance of the proposed control system is evaluated through computer simulations.