Nonlinear control of quadrotor UAV using Takagi-Sugeno fuzzy logic technique

A fuzzy logic controller was designed for a quadrotor unmanned aerial vehicle (UAV) with the aim of stabilizing it in the presence of atmospheric disturbances. Quadrotors are complex flying machines that are inherently unstable having both parametric and structural uncertainties. A mathematical model was designed and implemented into the MATLAB/Simulink environment in order to run simulations. The mathematical model proved to be a sufficient representation of the dynamics and physics of a quadrotor, incorporating all 6 degrees of freedom. A full system identification was performed in order to validate the three attitudes of the quadrotor, namely the roll, pitch and yaw angles. The Takagi-Sugeno (T-S) model used for the validation, together with the Band-Limited White noise signal ensured that all the dynamics of the system were excited. The T-S model yielded good results which gave the approval for the controller design. Simulation results showed that the performance of the controller designed was acceptable and can be improved by using global optimization techniques in the future.