System Architecture of Small Unmanned Aerial System for Flight Beyond Visual Line-of-Sight

142 Pages·2015·2.52 MB·English

by  Jason Png

SYSTEM ARCHITECTURE OF SMALL UNMANNED AERIAL SYSTEM FOR
FLIGHT BEYOND VISUAL LINE-OF-SIGHT

THESIS

Kwee Siam Seah, Military Expert 5 (Major), Republic of Singapore Air Force

AFIT-ENV-MS-15-S-047

DEPARTMENT OF THE AIR FORCE
AIR UNIVERSITY
AIR FORCE INSTITUTE OF TECHNOLOGY
Wright-Patterson Air Force Base, Ohio

DISTRIBUTION STATEMENT A.
APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED.
The views expressed in this thesis are those of the author and do not reflect the official
policy or position of the United States Air Force, Department of Defense, the United
States Government or the corresponding agencies of any other government. This material
is declared a work of the U.S. Government and is not subject to copyright protection in
the United States.
AFIT-ENV-MS-15-S-047

SYSTEM ARCHITECTURE OF SMALL UNMANNED AERIAL SYSTEM FOR
FLIGHT BEYOND VISUAL LINE-OF-SIGHT

THESIS

Presented to the Faculty
Department of Systems Engineering and Management
Graduate School of Engineering and Management
Air Force Institute of Technology
Air University
Air Education and Training Command
In Partial Fulfillment of the Requirements for the
Degree of Master of Science in Systems Engineering

Kwee Siam Seah, BS (Hons)
Military Expert 5 (Major), Republic of Singapore Air Force

September 2015
DISTRIBUTION STATEMENT A.
APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED.
AFIT-ENV-MS-15-S-047

SYSTEM ARCHITECTURE OF SMALL UNMANNED AERIAL SYSTEM FOR
FLIGHT BEYOND VISUAL LINE-OF-SIGHT

Kwee Siam Seah, BS (Hons)
Military Expert 5 (Major), Republic of Singapore Air Force

Committee Membership:

Dr. David R. Jacques
Chair

Dr. John M. Colombi
Member

Maj Scott Pierce, PhD
Member
AFIT-ENV-MS-15-S-047

Abstract
Small Unmanned Aerial Systems (UAS) have increasingly been used in military
application. The application in expanding scope of operations has pushed existing small
UAS beyond its designed capabilities. This resulted in frequent modifications or new
designs. A common requirement in modification or new design of small UAS is to
operate beyond visual Line-Of-Sight (LOS) of the ground pilot. Conventional military
development for small UAS adopts a design and built approach. Modification of small
Remote Control (RC) aircraft, using Commercial-Off-The Shelf (COTS) equipment,
offers a more economical alternative with the prospect of shorter development time
compared to conventional approach. This research seeks to establish and demonstrate an
architecture framework and design a prototype small UAS for operation beyond visual
LOS. The aim is to achieve an effective and reliable development approach that is
relevant to the military’s evolving requirements for small UASs. Key elements of the
architecture include Failure Mode Effect and Criticality Analysis (FMECA), fail safe
design for loss of control or communication, power management, interface definition, and
configuration control to support varying onboard payloads. Flight test was conducted
which successfully demonstrated a control handoff between local and remote Ground
Station (GS) for beyond visual LOS operations.

iv
AFIT-ENV-MS-15-S-047

Dedicated to my dear wife for your love and patience. To my 2 sons for being my
motivation in the period of research. To my parents and the rest of my family, for your
continual support.

v
Acknowledgments
I would like to thank my thesis committee, Dr David Jacques, Dr John Colombi
and Maj Scott Pierce. This thesis would not be possible without your guidance,
invaluable academic instruction and encouragement.

Kwee Siam
vi
Table of Contents
Page
Abstract .............................................................................................................................. iv
Acknowledgments.............................................................................................................. vi
Table of Contents .............................................................................................................. vii
List of Figures ......................................................................................................................x
List of Tables .................................................................................................................... xii
List of Abbreviations ....................................................................................................... xiv
I. Introduction .....................................................................................................................1
1.1 Problem Statement ..............................................................................................3
1.2 Objective .............................................................................................................4
1.3 Investigative Questions .......................................................................................4
1.4 Scope and Assumptions ......................................................................................5
1.5 Methodology .......................................................................................................5
1.6 Thesis Overview ..................................................................................................6
II. Literature Review ...........................................................................................................7
2.1 Classification of Military UAS ...........................................................................7
2.2 Airworthiness Requirement for UAS ..................................................................9
2.3 Failure Mode Effect and Criticality Analysis ...................................................12
2.4 Link Budget Analysis ........................................................................................13
2.5 Related Research ...............................................................................................16
2.6 Summary .........................................................................................................211
III. Methodology ...............................................................................................................22
3.1 Research Framework .........................................................................................22
3.2 System Architecture Development....................................................................26
vii
Page
3.3 Risk Management ..............................................................................................28
3.4 Incremental Flight Testing ................................................................................29
3.5 Design Approval ...............................................................................................29
3.6 Summary ...........................................................................................................29
IV. System Architecture and Risk Management...............................................................30
4.1 Specification Requirements...............................................................................30
4.2 System Architecture Development....................................................................33
4.3 Risk Management ..............................................................................................66
4.4 Intermediate Architecture ..................................................................................72
4.5 Iterative Testing of Intermediate Architecture ..................................................73
4.6 Bill of Material ..................................................................................................80
4.7 Final Architecture ..............................................................................................78
4.8 Summary ...........................................................................................................81
V. Test Results and Post Test Hazard Analysis ................................................................83
5.1 Incremental Test Flights ....................................................................................83
5.2 Post Fight Test Hazard Analysis .......................................................................91
5.3 Proposed Approach for Sequential Flight Test .................................................91
5.4 Summary ...........................................................................................................94
VI. Conclusions and Recommendations ...........................................................................95
6.1 Conclusions of Research ...................................................................................95
6.2 Significance of Research ...................................................................................97
6.3 Recommendations for Future Research ............................................................98
Bibliography ......................................................................................................................99
viii
Page
Appendix A: Failure Mode Effect and Criticality Analysis ............................................104
Appendix B: Setup for Pixhawk Autopilot Computer (ArduPilot, nd) ...........................115
Appendix C: Source Reference for Components in Architecture ....................................121
ix