Comparative robustness study of multivariable controller of fixed wing Ultrastick25-e UAV

in this paper three PID based control techniques were designed for discrete time model of Ultra stick UAV in both lateral and longitudinal channels. The three techniques are designed to enhance the control response of Ultra stick UAV. The robustness of the autopilot system to model uncertainty, the rejection of wind disturbances, and dealing with noise effect of sensors are considered as basic items for comparative study of the different control techniques. In the first control technique, the PID is designed and tuned using a genetic algorithm optimization technique. This is to improve the performance and robustness of the system. Adaptive PID fuzzy tuned is considered as the second control technique. Fuzzy tuning is based on seven triangular membership functions for each input and output, where the if-then rules are established based on expert knowledge. The third control technique is PID controller tuned using local optimal control. Each controller technique is designed based on linearized model and SISO decoupled subsystems. The designed controllers are then applied to the real nonlinear and MIMO model. The main contribution in this paper is applying PID controller tuned using local optimal control for the first time on fixed wing UAV. In addition to its simplicity, the comparative simulation results confirm the effectiveness of this controller technique over the other two controller techniques.