Nonlinear Modeling and Robust Backstepping Control of a Quadrotor Unmanned Aerial Vehicle

Abstract

Advances in software and hardware technologies have facilitated the production of quadrotor unmanned aerial vehicles (UAVs). Quadrotor UAVs are used in important missions such as search and rescue, counter terrorism, firefighting, surveillance and cargo transportation. While performing these tasks, quadrotors must operate in noisy environments. Therefore, a robust controller design that can control the altitude and attitude of the quadrotor in noisy environments is of great importance. While many researchers focus only on white Gaussian noise in their studies, all colored noises should be considered during quadrotor's operation. In this study, it is aimed to design a robust controller that is resistant to all colored noises. Firstly, a nonlinear model of the quadrotor was created with MATLAB. Then, a backstepping control design that is resistant to colored noises was realized. The designed backstepping controller was tested under Gaussian white noise, pink noise, brown noise, blue noise and purple noise. PID and Lyapunovbased controller designs were also carried out and their time responses (rise time, overshoot, settling time) were compared with those of backstepping controller. When the values obtained was examined, it was proven that the proposed backstepping controller had the least overshoot and shortest settling time under all noise types.