NDI/INDI Control Scheme for Tilt-rotorcraft Unmanned Aircraft Systems

Abstract

In this paper, a new control architecture is proposed to enable advanced Unmanned Aerial Vehicles to maneuver inside confined spaces to perform operations in Urban Search and Rescue missions and hazardous industrial spaces where sending humans is highly risky. The proposed controller is tested on a revolutionary highly maneuverable VTOL system first conceptualized by 4Front Robotics Ltd. presenting highly coupled dynamics enabling it to perform unique maneuvers such as pitch hover. To deal with the associated complexities and coupling motion effects inherent to such aircraft, a Nonlinear Dynamic Inversion (NDI) controller developed for position control, coupled with an Incremental Nonlinear Dynamic Inversion (INDI) controller designed for attitude control is described. The results for different flight maneuvers demonstrate effective the ability of the controller to control the position and orientation independently while tracking complex trajectories.