Model-Based Robust Tracking Attitude and Altitude Control of an Uncertain Quadrotor Under Disturbances

Quadrotor technology offers numerous potential applications, ranging from surveillance and power line inspection to medical delivery and more. However, achieving precise tracking control for these aircraft poses multiple challenges, including random wind disturbances, modeling uncertainties and other aerodynamic factors. To address these challenges, a new robust cooperative control scheme that combines the merits of backstepping control (BC) and non-singular fast terminal sliding mode control (NFTSMC) is developed. The super-twisting algorithm is also used to strengthen the system’s robustness and ensure the reachability of the sliding surfaces in a short time. The closed-loop stability of the proposed flight controller is demonstrated via the Lyapunov criteria. The suggested control scheme can drive the vehicle's attitude and altitude to the targeted trajectories in a short time while compensating for the influence of complex disturbances and modeling inaccuracies. The accuracy of the recommended control scheme was examined using a quadrotor aircraft exposed to random external disturbances and modeling uncertainties. Computer simulation as well as processor-in-the-loop (PIL) tests on a commercial autopilot board are executed to verify the effectiveness of the proposed strategy. Finally, multiple comparisons with recent nonlinear controllers are also realized to show the merit of the developed method.