Quadcopters have been gaining popularity in recent years as base aerial platforms for a number of civilian applications such as remote sensing, aerial imaging, firefighting, environmental measurement, law enforcement, disaster relief and a number of other military and commercial applications. Generally, quadcopters can be maneuvered by varying the power of the four motors in various ways – symmetrically or asymmetrically to achieve hover or translational flight. Traditionally, the quadcopter or multi rotor platforms have been assumed to have rigid frames and fixed geometries. While this is useful in countless operational scenarios, this also constrains their use in hard to reach or tight spaces. In this research effort, the authors explore the concept of Morphing Geometry quadcopters, which could enable the use of such aerial platforms in tight spaces. Within the context of our research, we define “Morphing Geometry” as (i) changes in the lengths of the opposing arms of the quadcopter and (ii) a change in the intersection angle between two pairs of opposing arms of the quadcopter. Changes in the geometry of the quadcopter results in changes in the moment of inertia about the perpendicular axis, as well as a corresponding change in the thrust and torques generated, directly affecting the controllability, stability, and performance of the quadcopter. Preliminary simulation results have shown that it is possible to maintain stability of the quadcopter platform, using a traditional PID controller while flying a race track pattern, incorporating morphed geometry in flight (conventional X to narrow X and back).
Publications:
1. Bai, Y.; Gururajan, S. Evaluation of a Baseline Controller for Autonomous “Figure-8” Flights of a Morphing Geometry Quadcopter: Flight Performance. Drones 2019, 3, 70.
2. Gururajan, S. and Bai, Y., “Autonomous “Figure-8” Flights of a Quadcopter: Experimental Datasets,” Data, Vol. 4, 2019, No. 1, http://www.mdpi.com/2306-5729/4/1/39, ISSN: 2306-5729, DOI: 10.3390/data4010039