Modelagem e simulação de uma aeronave multi-rotor não convencional

Abstract

The following work refers to the dynamic modelling of an unconventional unmanned air vehicle (UAV) that possesses hybrid lifting characteristics. It is able to change the angular orientation of a wing-rotor set, when referred to the fuselage reference line, which allows it to take off in a vertical path and then proceed flight horizontally on cruiser mode. The aircraft can be so defined as VTOL (Vertical Take Off and Landing) which employs aerodynamic surfaces and propellers to produce lifting. The use of three coaxial-rotors that tilt independently from the rest of the aircraft's body, turns the aircraft into a morphologically variable and asymmetric vehicle. The dynamic equations are defined from Classic Mechanics principles and the required aerodynamics' assumptions. A 3D model is produced in the CAD (Computing Aided Design) software SolidWorks® in order to obtain mass and inertia characteristics. To analyze the dynamic model, the aircraft's equations of motion are linearized into two different steady-state conditions and set into the form of state-spaces. The first steady-state condition refers to hover and the second one is thought as being the cruiser mode flight, in which the aircraft needs to maintain a certain flight speed to produce enough lifting on it's wings. The use of coaxial rotors allows to neglect gyroscopic effects caused by the tilt of each rotor with respect to the rest of the body. Finally, the dynamic behavior and stability criteria where evaluated for each one of the steady-state conditions with an algorithm implementation in the MATLAB® platform. The analysis of the aircraft's dynamic response to the possible aircraft's commands showed that it is a naturally unstable vehicle with the need of command inputs to reestablish a steady-state condition.