Autonomous VTOL design in quadcopter using feedback linearization and fuzzy T-S

Quadcopter is an unmanned aerial vehicle that is frequently used to model flying robot. Its four propellers let quadcopter move in rotation and in translation. Both rotation and translation systems are unstable and mathematically nonlinear. These 2 motion systems could be controlled separately. In this paper, we propose an autonomous vertical take-off and landing (VTOL) quadcopter using two controllers; each for one motion system. In rotation, settling time is critical issue, so that input-state feedback linearization is used to regulate/stabilize quadcopter. In translation, tracking error must be near to zero. Fuzzy Takagi Sugeno is used to control quadcopter in translation. Fuzzy Takagi-Sugeno is a genuine way to handle nonlinear system by linear controller using its so-called parallel distributed compensation. The nonlinear model of quadcopter is linearized and controlled at some operating points; Thus, we have some linear models and some linear controllers. Then, fuzzy system is utilized to decide which controller to work. The linear controller used in this paper has H infinity performance to attenuate disturbance. All terms are formulated in the form of linear matrix inequality (LMI) to find the appropriate gain with ease. The algorithms have been simulated with the help of MATLAB. The results show that the proposed controllers are able to stabilize quadcopter in 0 degrees' position for roll, pitch, and yaw as well as to track the given reference signal. Bounded disturbance can be attenuated thanks to H infinity performance.