X-Morf: A crash-separable quadrotor that morfs its X-geometry in flight

Abstract

The X-Morf robot is a 380-g quadrotor consisting of two independent arms each carrying tandem rotors, forming an actuated scissor joint. The X-Morf robot is able to actively change in-flight its X-geometry by changing the angle between its two arms. The magnetic and electrical joint between the quadrotors arms makes them easily removable and resistant to crashes while providing the propellers with sufficient power and ensuring high quality signal transmission during flight. The dynamic model on which the X-Morf robot was based, was also used to design an adaptive controller. A Model Reference Adaptive Control (MRAC) law was implemented to deal with the uncertainties about the inertia and the center of mass due to the quadrotors reconfigurable architecture and for in-flight span-adapting purposes. The tests performed with the X-Morf robot showed that it is able to decrease and increase its span dynamically by up to 28.5% within 0.5s during flight while giving good stability and attitude tracking performances.