Derivation Of The Dynamics Equations For Receiver Aircraft In Aerial Refueling

This thesis describes the derivation of a new set of nonlinear, 6--DOF equations of motion of a receiver aircraft undergoing an aerial refueling, including the effect of time-varying mass and inertia properties associated with the fuel transfer and the tanker's vortex induced wind effect. Since the center of mass of the receiver is time--varying during the fuel transfer, the equations are written in a reference frame that is geometrically fixed in the aircraft. Due to the fact that aerial refueling simulation and control deal with the position and orientation of the receiver relative to the tanker, the equations of motion are derived in terms of the translational and rotational position and velocity with respect to the tanker. Further, for the derivation, Newton's law is applied to the system, which consists of the receiver aircraft and the fuel before and after being transferred into the receiver. The new receiver equations of motion are implemented in an integrated simulation environment with a feedback controller for receiver station-keeping as well as the full set of nonlinear, 6--DOF equations of motion of the tanker aircraft and a feedback controller to fly the tanker on a U-turn maneuver.