Article
A Shape Memory Alloy Application for Compact
Unmanned Aerial Vehicles
Salvatore Ameduri
1,
*
,†
, Antonio Concilio
1,†
, Nunzia Favaloro
2,†
and Lorenzo Pellone
3,†
1
Adaptive Structures Department, Centro Italiano Ricerche Aerospaziali, Via Maiorise, Capua 81043, Italy;
a.concilio@cira.it
2
Space Exploration and Propulsion Facilities, Centro Italiano Ricerche Aerospaziali, Via Maiorise,
Capua 81043, Italy; n.favaloro@cira.it
3
Aeronautics Systems Engineering Department, Centro Italiano Ricerche Aerospaziali, Via Maiorise,
Capua 81043, Italy; l.pellone@cira.it
* Correspondence: s.ameduri@cira.it; Tel.: +39-823-623-556
† These authors contributed equally to this work.
Academic Editor: Javaan Chahl
Received: 2 March 2016; Accepted: 20 May 2016; Published: 31 May 2016
Abstract:
Shape memory alloys materials, SMA, offer several advantages that designers can rely
on such as the possibility of transmitting large forces and deformations, compactness, and the
intrinsic capability to absorb loads. Their use as monolithic actuators, moreover, can lead to potential
simplifications of the system, through a reduction of number of parts and the removal of many
free play gaps among mechanics. For these reasons, technological aerospace research is focusing
on this kind of technology more and more, even though fatigue life, performance degradation, and
other issues are still open. In the work at hand, landing gear for unmanned aerial vehicles, UAV, is
presented, integrated with shape memory alloys springs as actuation devices. A conceptual prototype
has been realized to verify the system ability in satisfying specs, in terms of deployment and retraction
capability. Starting from the proposed device working principle and the main design parameters
identification, the design phase is faced, setting those parameters to meet weight, deployment angle,
energy consumption, and available room requirements. Then, system modeling and performance
prediction is performed and finally a correlation between numerical and experimental results
is presented.
Keywords: shape memory alloys; landing gear; deployable systems
1. Introduction
Parachutes are used in a wide variety of applications, including sport activities, payload recovery,
military applications, and flood relief efforts. Paraglider is quite popular within the sports community.
Unlike the conventional round canopy parachutes, they have a large lift-to-drag ratio and are easily
maneuverable. Recently, defense organizations, all over the world, have shown a growing interest in
deploying paragliders for many applications.
Worthy of note are the works on the use of paragliders and UAVs performed by: Nagy and
Rohacs [
1
], related with the development of an unmanned system for testing different paragliders;
Eschmann et al. [
2
], aircraft platform management and autonomous software development; Jacob and
Smith [
3
], development, testing and integration of inflatable wings for small UAVs; [
4
], an assessment
of the viability of using a powered parafoil as an unmanned air vehicle for employment of Future
Combat System intelligence, surveillance, and reconnaissance unattended ground sensors (UGS);
and [5], lessons learned of the Parafoil Technology Demonstration (PTD) Project.
Shape Memory Alloys, SMA, due to their ability in transmitting large forces and deformations and
to their intrinsic compactness, may play a critical role as actuation and load absorbing elements within
Aerospace 2016, 3, 16; doi:10.3390/aerospace3020016 www.mdpi.com/journal/aerospace
