Original Article
JDMS
Journal of Defense Modeling and
Simulation: Applications,
Methodology, Technology
2014, Vol 11(1) 5–18
Ó 2012 The Society for Modeling
and Simulation International
DOI: 10.1177/1548512912450369
dms.sagepub.com
Neuro-optimal control of an
unmanned helicopter
David Nodland
1
,ArpitaGhosh
2
, H Zargarzadeh
1
and S Jagannathan
1
Abstract
Helicopter unmanned aerial vehicles (UAVs) can be extensively used for military missions as well as in civil operations,
ranging from multi-role combat support and search and rescue, to border surveillance and forest fire monitoring.
Helicopter UAVs are underactuated nonlinear mechanical systems with correspondingly challenging controller designs.
This paper presents an optimal controller design for tracking of an underactuated helicopter using an adaptive critic
neural network (NN) framework. The online approximator-based controller learns the infinite-horizon continuous-time
Hamilton–Jacobi–Bellman (HJB) equation and then calculates the corresponding optimal control input that minimizes the
HJB equation forward-in-time without using value and policy iterations. In the proposed technique, optimal tracking is
accomplished by a single NN, which is tuned online using a novel weight update law. Stability analysis is performed and
simulation results demonstrate the proposed control design.
Keywords
nonlinear optimal control, helicopter unmanned aerial vehicle (UAV), neural network (NN), online approximator (OLA),
Hamilton–Jacobi–Bellman (HJB) equation, trajectory tracking
1. Introduction
Helicopter unmanned aerial vehicles (UAVs) can play a
key role in numerous military applications, including
counter-explosive operations.
1
Key operational activities
for helicopter UAVs include:
1
‘‘Preventing an adversary from conducting activities that
result in the emplacement of IEDs [Improvised Explosive
Devices], thus thwarting an attack: this is likely to require use
of the full spectrum of Joint capabilities to defeat or disrupt
the adversary..’’
‘‘Detecting IED materiel and components, including stored
HME [Home-made Explosives] and smuggled components, as
well as emplaced devices themselves. This requires a combi-
nation of ISR [Intelligence, Surveillance, and Reconnaissance]
capability, together with responsive processes and effective
training, to ensure that potential IED activity detected is ana-
lyzed and the results disseminated to all those who need to be
aware of it, in order that appropriate action can be taken as
swiftly as possible.’’
There are a number of specific ways that helicopter
UAVs can counter threats:
1
‘‘In simple terms, A & S [Air & Space] Power is capable of
defeating emplaced IEDs by detecting devices and by neutra-
lizing and mitigating their effects, as follows: Detecting
devices using dedicated airborne and Space-based ISR and
airborne Non-Traditional ISR (NTISR), exploiting existing
capabilities and capitalizing on technological enhancements,
including those offered by CCD technology.’’
These devices can be neutralized or have their effects
mitigated through
‘‘Airborne EW [Electronic Warfare] capabilities, including
Electronic Attack (EA), by employing ECM [Electronic
1
Department of Electrical and Computer Engineering, Missouri
University of Science and Technology, Rolla, MO, USA
2
National Metallurgical Laboratory, Jamshedpur, India
Corresponding author:
S Jagannathan, Department of Electrical and Computer Engineering,
Missouri University of Science and Technology, 1870 Miner Circle, Rolla,
MO 65409, USA.
Email: sarangap@mst.edu
at UNIV OF WISCONSIN OSHKOSH on June 9, 2015dms.sagepub.comDownloaded from
