Adaptive attitude and speed controller of a fixed wing UAV with disturbance observer

In this article an adaptive controller and a disturbance observer has been developed for attitude and speed control of a fixed wing Unmanned Aerial Vehicle(UAV). Attitude dynamic model of UAVs is multi input multi output (MIMO), strong coupling and nonlinear.Model uncertainties and disturbance should beconsidered during the attitude control system for UAVs. The speed dynamic model may be encountered with similar problem. So, designing a controller that track the desired attitude and speed commands in these conditions is the main goal of this paper. First of all, the adaptive controller will be design for the attitude dynamic model, considering MIMO model, unknown parameter in the moment of inertia and external disturbances. Then the disturbance observer will be added to the attitude controller to handle these disturbances. Thirdly, the nonlinear adaptive speed controller will be developed with considering unknown parameters in the engine model. Throttle, elevator, aileron and rudder are four available control inputs. The stability analysis of closed loop system is investigated by Lyapunov function that guarantees closed-loop system stability. In order to demonstrate the performance of designed controller, the ۶DOF nonlinear simulation performed in MATLAB. Results show that the tracking objectives has been achieved in presence of model uncertainties and external disturbances.

کلیدواژه ها:

Adaptive control ، Attitude dynamic ، speed control ، disturbance observer ، Uncertainties