Trajectory tracking for a Non-Conventional UAV

The aim of the present paper is the design of aflight control system for a Tandem – CanardUAV, useful in the whole flight envelope, bothOut of Ground Effect (OGE) and In GroundEffect (IGE) conditions. Because of theparticular arrangement of the studied aircraft, ageneral mathematical model has been built inorder to obtain non-linear analytical equationsfor longitudinal aerodynamic coefficients bothin OGE and in IGE flight. So the dynamicbehaviour of the UAV may be studied duringevery flight phases i.e. in the whole range ofaltitude. To consider the strong variation ofaerodynamic parameters due to the groundeffect presence, a robust control technique(LQG/LTR) has been used to design the controlsystem. Because Phugoid mode is stronglyaffected by ground effect, a StabilityAugmentation System has been implemented inorder to increase Phugoid damping. Thecontroller has shown suitability to track bothout of ground effect and in ground effecttrajectories. Besides, it possesses robustnessproperties either in presence of winddisturbances.