Computational modelling of time aeromechnaics and flight control of a quadrotor unnamed aerial vehicle

Quadrotor helicopters are emerging as a popular platform for unmanned aerial vehicle (UAV) research, due to the simplicity of their construction and maintenance, their ability to hover, and their vertical takeoff and landing (VTOL) capability. Quadrotor Unmanned Aerial Vehicle (UAV) has adapted to rapid response and high terrain capability, and now widely be used for reconnaissance, transporting supplies etc. The dynamical motion of a quadrotor UAV is achieved by controlling the angular speeds of the four propellers (rotors). The model has four input forces which are basically the thrusts provided by each propeller to the UAV body at fixed



angles. Forward (backward) motion is maintained by increasing (decreasing) speed of front (rear) rotor speed while decreasing (increasing) rear (front) rotor speed simultaneously which means changing the pitch angle. Left and right motion is accomplished by changing the speed of left and right rotor by the same way. The front and rear motors rotate counterclockwise while other motors rotate clockwise so that the yaw command is derived by increasing (decreasing) counter-clockwise motors speed while decreasing (increasing) clockwise motor speeds. The controller is used to obtain the desired speed of the quadrotor rotor for the desired maneuver. In this work, the computation is performed based on computational fluid dynamics (CFD) coupled with rigid body dynamics (RBD) and flight control law. This study involves the integration of rigid body dynamics, control, and maneuvering of a quadrotor with CFD software based on three-dimensional, incompressible Navier-Stokes equations with a turbulence model. The one equation Spalart- Allmaras turbulence model is employed to close the governing equations. The dynamic fluid body interaction (DFBI) equations are used to obtain the body position and orientation of the quadrotor. The movement of quadrotor and propeller are handled using overset-mesh topology. The Proportional-Integral-Derivative (PID) and the LinearQuadratic-Regulator controller are used to obtain the required trajectory of the quadrotor. The controllers are designed in a MATLAB and coupled with the flow solver. The method is applied to the problem of the quadrotor in a free flight and near the ground to understand the change in performance of the UVA.