Control of a Receiver Aircraft Relative to the Tanker in Racetrack Maneuver

This paper addresses the problem of controlling the receiver aircraft to achieve a successful aerial refueling. A position-tracking controller has been designed using "gain scheduling" technique based on a combination of integral control and optimal LQR design. The scheduling is utilized to satisfy the performance requirement of the controller during the whole "racetrack" maneuver of the tanker in a standard aerial refueling operation. The nominal ∞ight conditions that are used for the linearization of the nonlinear equations of motion are (i) straight wing-level ∞ight and (ii) steady turn. The controller does not use the information of the tanker’s vortex induced wind efiects acting on the receiver aircraft. The position tracking controller can be used for (i) ∞ying from observation position to the refueling position, (ii) station keeping during the actual fuel transfer and (iii) ∞ying away from the refueling position once the fuel transfer is completed. The performance of the controller is evaluated in the high fldelity simulation environment, which, employing the new sets of equations of motion, includes the relative motion of the receiver and the tanker and the aerodynamic coupling due to the trailing vortex of the tanker. The simulation and control design are applied to a tailless flghter aircraft with innovative control efiectors and thrust vectoring capability.