Flight Mechanics, Aerodynamics and Modelling of Quadrotor

Abstract

In recent years, quadrotors are one of the most popular platforms for the development of unmanned aerial vehicles, and their application trend is rapidly increasing for both commercial and research purposes. Their main advantages compared to other types of flying vehicles are the ability to hover, minimal operating space, vertical take-off, and landing capability, as well as smaller overall dimensions. However, their breakthrough into the market is due to their longer flight time and the fact that today they can carry much more payload. This paper aims to present the basic idea behind the conceptual development of the quadrotor, with special reference to aerodynamic effects that are important for this type of aircraft. It will be shown that, although thrust force is represented by simplified equations in literature, in the general case it depends on the vehicular velocity and its angle of attack. Therefore, its expressions will be different and will depend on flight mode, as is shown in the paper. Furthermore, it will be presented that less power is needed for the same thrust force when the quadrotor flights near the ground. The main advantages of the quadrotor concept will be explained, where it will be shown that blade flapping and the gyroscopic effect can be significantly suppressed due to the opposite direction of rotation of the rotor. The kinematic model is given and the formulated dynamic model is based on Newton-Euler formalism.