Aerospace 2015, 2, 325-352; doi:10.3390/aerospace2020325
OPEN ACCESS
aerospace
ISSN 2226-4310
www.mdpi.com/journal/aerospace
Article
A Comparison of Closed-Loop Performance of Multirotor
Configurations Using Non-Linear Dynamic Inversion Control
Murray L. Ireland *, Aldo Vargas and David Anderson
School of Engineering, University of Glasgow, University Avenue, Glasgow G12 8QQ, UK;
E-Mails: a.vargas-moreno.1@research.gla.ac.uk (A.V.); Dave.Anderson@glasgow.ac.uk (D.A.)
* Author to whom correspondence should be addressed; E-Mail: Murray.Ireland@glasgow.ac.uk;
Tel.: +44-141-330-8646.
Academic Editor: Rafic Ajaj
Received: 23 April 2015 / Accepted: 1 June 2015 / Published: 5 June 2015
Abstract: Multirotor is the umbrella term for the family of unmanned aircraft, which include
the quadrotor, hexarotor and other vertical take-off and landing (VTOL) aircraft that employ
multiple main rotors for lift and control. Development and testing of novel multirotor designs
has been aided by the proliferation of 3D printing and inexpensive flight controllers and
components. Different multirotor configurations exhibit specific strengths, while presenting
unique challenges with regards to design and control. This article highlights the primary
differences between three multirotor platforms: a quadrotor; a fully-actuated hexarotor;
and an octorotor. Each platform is modelled and then controlled using non-linear dynamic
inversion. The differences in dynamics, control and performance are then discussed.
Keywords: multirotor; quadrotor; hexarotor; octorotor; non-linear dynamic inversion;
non-linear control
1. Introduction
A multirotor is a rotorcraft, but differ from traditional helicopter configurations. Rather than
employing mechanically-complex main and tail rotors, a multirotor employs several identical rotors
to provide both lift and control. The flexibility of the platform has led to the popular application
as an unmanned aerial vehicle (UAV). A prominent example of this is the quadrotor, which has seen
