Comparison of Vertical and Bird Take-off Methods of Quad-Plane Miniature Aerial Vehicles

This paper compares the two take-off methods; vertical take-off and bird take-off for quad-plane unmanned aerial vehicles. Energy consumption and flying quality of the two methods are assessed. Often, the quad-plane aerial vehicles take off vertically using the quad mode, and when the reference altitude is reached the plane mode kicks in. The rarely used bird take-off mode, uses both quad and plane modes kick in together at the take-off so that the UAV gains the altitude and airspeed symultaneously lower energy. The experiments were carried out with a 1.35kg quad-plane on a two short flights conducted back-to-back under similar environmental conditions. It has been found from the flight data that the bird take-off helps quad-plane to fly 10.8\% more distance for a unit of energy than with the vertical take-off. It was also observed that the VTO method shows sudden altitude drop during the quad to plane control transition.