Assessment of Quadrotor Near-Wall behaviour using six-Degrees of Freedom CFD simulations

The growth of Unmanned Aerial Systems (UASs) in various applications requires more autonomous and safe missions. The paper introduces an innovative approach that combines the Computational Fluid Dynamics (CFD) model and closed-loop control algorithm to simulate UAS maneuvers precisely. This study proposes a Proportional-Integrative-Derivative (PID) controller for both position and attitude dynamics due to its simple implementation and employment in a commercial autopilot system. Thanks to the numerical simulation of the UAS aerodynamics, it was possible to perform an accurate analysis, especially for critical conditions, such as wall effect or rapid wind gusts. In these particular situations, it is essential to exploit an advanced propulsive model to capture the interaction between vehicle dynamics, aerodynamics, and environmental conditions. The complete CFD/PID framework enables a virtual testing environment for UAS platforms. The paper compares an innovative in-the-loop CFD approach and a classical simplified propulsive model that adopts constant thrust and torque coefficients to verify the numerical model. Furthermore, we present numerical simulations of a quadcopter in the neighborhood of a wall studying the ability of the discussed control algorithm to maintain a hovering position at different distances from the wall.