Way Point Tracking of Fixed-Wing Unmanned Aerial Vehicles Using Backstepping Controller and Fuzzy Logic

Nowadays, operational usage of Unmanned Aerial Vehicles (UAVs) in various missions is increasing, considering their capabilities. Provided that there is coordination between the UAV, navigation and control system, the operational capability of the UAVs increases. Since there is no pilot in UAVs, the task of guidance and control of the UAV for carrying out the mission depends on the ability of the autopilot and guidance system. This paper regards the control and the guidance as separate entities in the waypoint tracking problem. To do so, the outer loop generates the backstepping controller design for the inner loop to track the commands. The outer loop is designed based on fuzzy logic. The proposed system uses standard Mamdani fuzzy controllers that provide autopilot speed, heading, and flight path angle references. Nonlinear six-degree-of-freedom equations of motion are used to model the vehicle dynamics. Simulations were carried out to verify the performance of the system. The results indicate the ability of the waypoint tracking system to track the desired set of waypoints.