Avionics and Control System Development for Mid-Air Rendezvous of Two Unmanned Aerial ...

181 Pages·2005·2.99 MB·English

Avionics and Control System Development for Mid-Air
Rendezvous of Two Unmanned Aerial Vehicles
by
Sanghyuk Park
Submitted to the Department of Aeronautics and Astronautics
in partial fulfillment of the requirements for the degree of
Doctor of Philosophy in Aeronautics and Astronautics
at the
MASSACHUSETTS INSTITUTE OF TECHNOLOGY
February 2004
(cid:176)c Massachusetts Institute of Technology 2004. All rights reserved.
Author............................................................................
Department of Aeronautics and Astronautics
November, 2003
Certified by........................................................................
John J. Deyst
Professor of Aeronautics and Astronautics
Thesis Supervisor
Certified by........................................................................
Jonathan P. How
Associate Professor of Aeronautics and Astronautics
Thesis Supervisor
Certified by........................................................................
James D. Paduano
Principal Research Engineer of Aeronautics and Astronautics
Thesis Supervisor
Certified by........................................................................
Brent D. Appleby
Principal Member of Technical Staff at Draper Laboratory
Thesis Supervisor
Accepted by.......................................................................
Edward M. Greitzer
H.N. Slater Professor of Aeronautics and Astronautics
Chairman, Committee on Graduate Students
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Avionics and Control System Development for Mid-Air Rendezvous of
Two Unmanned Aerial Vehicles
by
Sanghyuk Park
Submitted to the Department of Aeronautics and Astronautics
on November, 2003, in partial fulfillment of the
requirements for the degree of
Doctor of Philosophy in Aeronautics and Astronautics
Abstract
Aflightcontrolsystemwasdevelopedtoachievemid-airrendezvousoftwounmannedaerial
vehicles (UAVs) as a part of the Parent Child Unmanned Aerial Vehicle (PCUAV) project
at MIT and the Draper Laboratory.
A lateral guidance logic was developed for tightly tracking a desired flight path. The
guidance logic is derived from geometric and kinematic properties, and has been demon-
strated to work better than the conventional aircraft guidance method in waypoint naviga-
tion.
Asimple,low-orderattitudeestimationwasdevelopedthatcombinesaircraftkinematics,
GPS and low-quality rate gyros. It is demonstrated in simulation that the performance of
theproposedmethodisasgoodasotheradvancedcomplexmethodswhentheaircraftbank
angle is relative small(<40 degrees).
The end-game control strategy for the final phase of the rendezvous was also devel-
oped, using proportional navigation guidance in conjunction with an optical sensor. The
associated miss distance was analyzed with regard to the wind effect and initial conditions.
A series of flight tests was performed using two UAVs which were built as a part of
the project. It was demonstrated that each individual aircraft can follow a desired flight
path within a position accuracy of 2 meters (based on sensor data) while also tracking
the air speed command to within 1 m/s. At the time of this thesis writing, it has been
demonstratedthatthedevelopedcontrolsystemcanbringthetwoUAVsfromanyarbitrary
initial positions into a configuration of a tight formation flight, where one vehicle trails the
other with a commanded separation of 12 meters while maintaining the relative position
error within 2 meters in both horizontal and vertical directions for 85% of the flight time.
Thesis Supervisor: John J. Deyst
Title: Professor of Aeronautics and Astronautics
Thesis Supervisor: Jonathan P. How
Title: Associate Professor of Aeronautics and Astronautics
Thesis Supervisor: James D. Paduano
Title: Principal Research Engineer of Aeronautics and Astronautics
Thesis Supervisor: Brent D. Appleby
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Title: Principal Member of Technical Staff at Draper Laboratory
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Acknowledgments
I would like to express my sincere gratitude to the following people. Without them all the
excitement that I had in this project would have been impossible.
I would like to thank Professor John J. Deyst for giving me the opportunity to work
on this exciting team project, and for his guidance and consistent motivation throughout
my past five years at MIT. Thank you to Professor Jonathan P. How for his advice and
help, especially for guiding me to think through the trajectory-tracking logic from different
points of view. Thanks to his help I was able to come up with a right explanation for that.
I would like to thank Professor James D. Paduano for his cordial concern and advice from
the countless meetings, and also specifically for guiding me in organizing the thesis and
the defense. Thank you to Dr. Brent D. Appleby. I appreciate his advice and support
throughout the project, and for introducing this exciting project to MIT from Draper
Laboratory.
I would like to thank Sean George, Vladislav Gavrilets, and Kyungyeol Song, who
provided many valuable insights through many discussions. I would like to thank Donald
Weiner and Richard Perdichizzi, who taught me how to use many interesting machines in
the department work shop and helped me doing lots of experiments throughout the project.
ThankyoutoRuaneCrummettandMitchBuckley,ourpilots,whosavedouraircraftmany,
many times.
I would like to thank the students who have been in the project. It was a wonderful
thing to have a lab-mate like Damien Jourdan for the last three years. I appreciate the
friendship with Thomas Jones, who also shared many discussions and ideas throughout
the project. Thank you, Francois Urbain and Jason Kepler, who built our amazing two
aircraft, for their exceptional friendship. Thank you, Richard Poutrel, who worked on the
communication parts and also played some tennis and soccer together. Thank you, Sarah
Saleh for creating warm and friendly atmosphere in the lab during her stay. I appreciate
the friendship from Alexander Omelchenko who has been with me for the last five years
in the project. I would like to thank Hyungil Ahn, Anand Srinivas, Damian Toohey and
Joshua Torgerson, who recently joined the project, but we had lots of fun together. I would
like to thank other friends at school. Thank you Simon, Xueen, Taehong and Hyuntae.
I would like to thank my father-in-law, who showed consistent interest in what I was
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doing here. Thank you, my mother-in-law, who shared many interesting and funny stories
from time to time. And thank you, my sister-in-law for her cordial concern and friendly
support.
I owe infinite gratitude to my family in Korea. Thank you, my Mom and Dad, and my
Uncle and Aunt for their unconditional love and support. Thank you, my two brothers,
Jihyuk and Jeoung-hyuck hyung for their concern and support.
Finally I would like to thank the most important person in my life, my lovely wife
Jiyoon, for her exceptional understanding, concern, and support. I love you.
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Contents
1 Introduction and Overview 17
1.1 Background and Objective . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
1.2 Approach and Challenges . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
1.3 Research Contributions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
1.3.1 Theoretical Contributions . . . . . . . . . . . . . . . . . . . . . . . . 21
1.3.2 Experimental Contributions . . . . . . . . . . . . . . . . . . . . . . . 21
1.4 Thesis Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2 Experimental Setup 25
2.1 Demonstration Vehicles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
2.1.1 Mini - Child Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
2.1.2 Outboard Horizontal Stabilizer(OHS) - Parent Vehicle . . . . . . . . 27
2.2 Avionics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
2.3 Modeling and Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
2.4 Controller Design and Analysis . . . . . . . . . . . . . . . . . . . . . . . . . 33
2.4.1 Lateral Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
2.4.2 Longitudinal Controller . . . . . . . . . . . . . . . . . . . . . . . . . 34
2.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
3 Guidance for Phase I of Mid-Air Rendezvous 37
3.1 Phase I Path Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
3.2 Prior Work on Guidance Methods . . . . . . . . . . . . . . . . . . . . . . . 38
3.2.1 Cross-track Error Guidance . . . . . . . . . . . . . . . . . . . . . . . 39
3.2.2 Lateral Track Control Law for Aerosonde UAV - Marius Niculescu
(2001) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
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3.2.3 Guidance Laws for tactical Missiles . . . . . . . . . . . . . . . . . . . 41
3.3 Lateral Guidance Logic for Trajectory Following . . . . . . . . . . . . . . . 42
3.3.1 Understanding the Mechanism of the Nonlinear Guidance Logic . . . 44
3.3.2 Relation to Missile Guidance Laws . . . . . . . . . . . . . . . . . . . 45
3.3.3 Linear Properties and Selection of L . . . . . . . . . . . . . . . . . 48
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3.3.4 Comparison of the New Guidance Logic with the Traditional Linear
Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
3.3.5 Decomposition of the Angle η . . . . . . . . . . . . . . . . . . . . . . 52
3.3.6 Characterization of Trajectory Error in the Nonlinear Guidance Logic 53
3.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
4 Estimation 59
4.1 Prior Work on Attitude Estimation . . . . . . . . . . . . . . . . . . . . . . . 59
4.1.1 Traditional Attitude Heading Reference Systems with Inertial Navi-
gation System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
4.1.2 INS/GPS Integration . . . . . . . . . . . . . . . . . . . . . . . . . . 59
4.1.3 Multi-Antenna GPS based Attitude Determination . . . . . . . . . . 60
4.2 Prior Work on Attitude Estimation Using Aircraft Kinematics . . . . . . . 60
4.2.1 Bank Angle Estimation Using a Complementary Filter with Roll and
Yaw Rate Gyros . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
4.2.2 Single-Antenna GPS Based Aircraft Attitude Determination . . . . 61
4.3 Simple,Low-orderAttitudeEstimationCombiningAircraftKinematics,GPS
and Low Quality Inertial Sensors . . . . . . . . . . . . . . . . . . . . . . . . 62
4.3.1 Estimation of Bank Angle and Biases in Roll/Yaw Rate Gyros . . . 62
4.3.2 Bias Estimation in Pitch Rate Gyro . . . . . . . . . . . . . . . . . . 66
4.3.3 Flight Test Data : Rate Gyro Bias Estimation . . . . . . . . . . . . 68
4.3.4 Comparison with a Multi State Extended Kalman Filter . . . . . . . 69
4.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
5 Guidance for Phase II of Mid-Air Rendezvous 73
5.1 Phase II Guidance Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
5.2 Acceleration Commands to Inner-Loop Controller and Unconventional Con-
trol Surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
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5.3 Linearization and Method of Adjoints for Miss Distance Analysis . . . . . . 78
5.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
6 Flight Test Results 87
6.1 Flight Test of Individual Aircraft . . . . . . . . . . . . . . . . . . . . . . . . 87
6.2 Flight Test of Rendezvous Phase I . . . . . . . . . . . . . . . . . . . . . . . 90
6.3 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
7 Summary and Recommendations 97
7.1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
7.2 Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
A Detailed Description of Avionics 101
A.1 Hardware Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
A.2 Overview of Avionics Components and Ground Station. . . . . . . . . . . . 105
A.3 Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
A.4 Avionics Diagrams for OHS Parent Vehicle . . . . . . . . . . . . . . . . . . 122
B Modeling and Simulation 133
B.1 Geometric and Inertial Properties . . . . . . . . . . . . . . . . . . . . . . . . 133
B.2 Equations of Motions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
B.3 Aerodynamic Forces and Moments . . . . . . . . . . . . . . . . . . . . . . . 136
B.4 Actuator and Sensor Modeling . . . . . . . . . . . . . . . . . . . . . . . . . 138
B.5 Wind Effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
B.6 Trim Analysis and Linearization . . . . . . . . . . . . . . . . . . . . . . . . 141
B.7 OHS Tail Boom Flexibility . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
B.8 Downwash behind OHS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
C Controller Design and Analysis 149
C.1 Lateral and Directional Controller . . . . . . . . . . . . . . . . . . . . . . . 149
C.2 Longitudinal Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
C.3 Implementation of Smooth Transition and Anti-Windup . . . . . . . . . . . 158
D Other Estimation Filters 163
D.1 Estimation of Position/Velocity/Acceleration using GPS . . . . . . . . . . . 163
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D.2 Estimation of Pitch Angle . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
D.3 Estimation of Altitude Rate and Altitude . . . . . . . . . . . . . . . . . . . 166
D.4 Estimation of Angle of Attack . . . . . . . . . . . . . . . . . . . . . . . . . . 167
E Line-of-Sight Rate Computation 169
F Flight Data - Phase I Trajectories 173
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