| This thesis analyzes a group of Unmanned Aerial Vehicles (UAVs) flying in close proximities from three major standpoints---the dynamic modeling, control design and computer simulation. In the dynamics modeling, a simple and versatile multi-aircraft model has been evolved by introducing a Virtual Leader's (VL) frame as its reference. Nonlinear 6-DOF, rigid body, equations of motion developed in the VL frame are used to model the UAVs in the group. The nonlinear equations of motion contain the wind effect terms and their time derivatives to represent the aerodynamic coupling involved in close-proximate flight. These wind terms are obtained using a novel averaging technique that computes the effective induced wind components and wind gradients in the UAVs body frame. This way, the equations of motion based on the assumption that the aircraft is exposed to uniform wind components and gradients can be used. This is because the averaging technique approximates the non-uniform wind field as uniform wind components and gradients. (Abstract shortened by UMI.)... |
