Online Path Planning And Control Solution For A Coordinated Attack Of Multiple Unmanned Aerial

143 Pages·2017·3.17 MB·English

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Electronic Theses and Dissertations, 2004-2019
2012
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Juan Vega-Nevarez
University of Central Florida
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Vega-Nevarez, Juan, "Online Path Planning And Control Solution For A Coordinated Attack Of Multiple
Unmanned Aerial Vehicles In A Dynamic Environment" (2012). Electronic Theses and Dissertations,
2004-2019. 2430.
https://stars.library.ucf.edu/etd/2430
ONLINE PATH PLANNING AND CONTROL SOLUTION FOR A COORDINATED
ATTACK OF MULTIPLE UNMANNED AERIAL VEHICLES IN A DYNAMIC
ENVIRONMENT

by

JUAN E. VEGA-NEVÁREZ
B.S. University of Puerto Rico, 2003

A thesis submitted in partial fulfillment of the requirements
for the degree of Master of Science
in the School of Electrical Engineering and Computer Science
in the College of Engineering and Computer Science
at the University of Central Florida
Orlando, Florida

Fall Term
2012

Major Professor: Zhihua Qu
© 2012 Juan E. Vega-Nevárez

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ABSTRACT
The role of the unmanned aerial vehicle (UAV) has significantly expanded in the military
sector during the last decades mainly due to their cost effectiveness and their ability to
eliminate the human life risk. Current UAV technology supports a variety of missions
and extensive research and development is being performed to further expand its
capabilities. One particular field of interest is the area of the low cost expendable UAV
since its small price tag makes it an attractive solution for target suppression. A swarm
of these low cost UAVs can be utilized as guided munitions or kamikaze UAVs to attack
multiple targets simultaneously. The focus of this thesis is the development of a
cooperative online path planning algorithm that coordinates the trajectories of these
UAVs to achieve a simultaneous arrival to their dynamic targets. A nonlinear autopilot
design based on the dynamic inversion technique is also presented which stabilizes the
dynamics of the UAV in its entire operating envelope. A nonlinear high fidelity six
degrees of freedom model of a fixed wing aircraft was developed as well that acted as
the main test platform to verify the performance of the presented algorithms.

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To my wife María and my beautiful daughter Monique.

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ACKNOWLEDGMENTS
I would like to express my gratitude to my advisor Dr. Zhihua Qu for his guidance,
support, and overall, for his infinite patience. I would also like to thank my dearest
friends Ricardo Colón, Ricardo Elías, and Leticia Delgado for their continuous support
and constant harassment to obligate me complete this thesis.

I would also like to offer my most heartfelt gratitude to my greatest mentor, my
grandfather Juan Nevárez, since his guidance and example have been some of the
main elements for defining who I am today.

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TABLE OF CONTENTS
LIST OF FIGURES ..........................................................................................................ix
LIST OF TABLES ........................................................................................................... xii
LIST OF ACRONYMS ................................................................................................... xiv
CHAPTER 1: INTRODUCTION................................................................................... 1
CHAPTER 2: MODELING AND NAVIGATION FUNDAMENTALS ............................. 4
2.1 Geodesy ............................................................................................................. 4
2.1.1 Earth’s Gravity Model .................................................................................. 5
2.2 Coordinate Frames and Transformations ........................................................... 6
2.2.1 Earth Centered Inertial (ECI) Frame ............................................................ 6
2.2.2 Earth Centered Earth Fixed (ECEF) Frame ................................................. 7
2.2.3 Local Geodetic Plane .................................................................................. 8
2.2.4 Body Fixed Coordinate Frame ..................................................................... 9
2.2.5 ECI to ECEF Conversion ........................................................................... 10
2.2.6 ECEF to Local Tangent Plane Conversion ................................................ 11
2.2.7 Local Tangent Plane to Body Conversion.................................................. 11
2.3 Rigid Body Equations of Motion ....................................................................... 12
2.3.1 Rotational Dynamics .................................................................................. 13
2.3.2 Translational Dynamics ............................................................................. 15
2.3.3 Rotational Kinematics ................................................................................ 15
2.3.4 Translational Kinematics ............................................................................ 19
2.4 Basic Aerodynamics ......................................................................................... 19
CHAPTER 3: MODELING THE NONLINEAR UAV ................................................... 23
3.1 Nonlinear 6-DOF Model Overview ................................................................... 24
3.2 Actuator Models ............................................................................................... 27
3.3 Atmospheric Model .......................................................................................... 29
3.4 Aerodynamics Model ........................................................................................ 32
3.4.1 Aerodynamic Damping Derivatives ............................................................ 34
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3.4.2 Drag Coefficient ......................................................................................... 36
3.4.3 Sideforce Coefficient ................................................................................. 37
3.4.4 Lift Coefficient ............................................................................................ 38
3.4.5 Rolling Moment Coefficient ........................................................................ 39
3.4.6 Pitching Moment Coefficient ...................................................................... 42
3.4.7 Yawing Moment Coefficient ....................................................................... 44
3.4.8 Aerodynamic Forces and Moments ........................................................... 46
3.5 Propulsion Model ............................................................................................. 47
3.6 6-DOF Equations of Motion Model ................................................................... 53
CHAPTER 4: CONTROLLING THE NONLINEAR UAV ............................................ 59
4.1 Fundamentals of the Dynamic Inversion Technique ........................................ 60
4.2 Derivation of Wind Axis Dynamic Equations .................................................... 62
4.3 Nonlinear Autopilot Overview ........................................................................... 65
4.4 Nonlinear Autopilot Design ............................................................................... 69
4.4.1 Inner Loop: Angular Velocity Controller ..................................................... 69
4.4.2 Middle Loop: Attitude Controller ................................................................ 72
4.4.3 Outer Loop: Velocity Controller .................................................................. 75
4.5 Autopilot Simulation Implementation and Results ............................................ 79
4.5.1 Autopilot Simulink Implementation ............................................................. 79
4.5.2 Angular Velocity Controller Results ........................................................... 81
4.5.3 Attitude Controller Results ......................................................................... 84
4.5.4 Velocity Controller Results ......................................................................... 86
4.5.5 Trajectory Tracking Results ....................................................................... 90
CHAPTER 5: COORDINATED ATTACK OF MULTIPLE UAVS ............................... 94
5.1 Aircraft Kinematic Constraints .......................................................................... 95
5.2 Online Trajectory Planning for Single UAV ...................................................... 95
5.3 Estimation of Target Velocity and Intercept Point ............................................. 98
5.3.1 Estimation of Target Position and Velocity ................................................ 99
5.3.2 Estimation of Intercept Point and Final Boundary Conditions .................. 102
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5.4 Trajectory Coordination for Multiple UAVs ..................................................... 105
5.4.1 Estimation of Trajectory Arc Length ......................................................... 106
5.4.2 Calculation of the Optimization Parameters ............................................. 108
5.5 Derivation of Guidance Commands ............................................................... 110
5.6 Simulation Results ......................................................................................... 111
5.6.1 Path Planning Algorithm Simulink Implementation .................................. 111
5.6.2 Effects of the Optimization Parameters on the UAV Trajectory ............... 113
5.6.3 Simulation Results for Single UAV Attack ................................................ 115
5.6.4 Simulation Results for Coordinated Attack of Multiple UAVs ................... 119
5.7 Future Considerations .................................................................................... 123
CHAPTER 6: CONCLUSION .................................................................................. 124
LIST OF REFERENCES ............................................................................................. 127

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LIST OF FIGURES
Figure 2-1: Earth Centered Inertial (ECI) Frame ............................................................. 7
Figure 2-2: Earth Centered Earth Fixed (ECEF) Frame .................................................. 8
Figure 2-3: Local Tangent Plane with NED convention ................................................... 9
Figure 2-4: Body Fixed Coordinate Frame .................................................................... 10
Figure 2-5: Basic Aircraft Forces ................................................................................... 19
Figure 2-6: Wing Airfoil .................................................................................................. 20
Figure 2-7: Definition of Aerodynamic Moments ........................................................... 21
Figure 3-1: Nonlinear 6-DOF UAV Simulink Model ....................................................... 25
Figure 3-2: UAV Model Flow Diagram ........................................................................... 27
Figure 3-3: Simulink Actuator Model ............................................................................. 28
Figure 3-4: Standard Atmosphere 1976 Simulink Model ............................................... 32
Figure 3-5: Aerodynamics Simulink Model .................................................................... 33
Figure 3-6: Airspeed and Aerodynamic Angles Simulink Implementation ..................... 34
Figure 3-7: Drag Coefficient Simulink Implementation .................................................. 37
Figure 3-8: Sideforce Coefficient Simulink Implementation ........................................... 38
Figure 3-9: Lift Coefficient Simulink Implementation ..................................................... 39
Figure 3-10: Rolling Moment Coefficient Simulink Implementation ............................... 42
Figure 3-11: Pitching Moment Coefficient Simulink Implementation ............................. 43
Figure 3-12: Yawing Moment Coefficient Simulink Implementation .............................. 46
Figure 3-13: Implementation of Aerodynamic Forces and Moments Scaling ................ 47
Figure 3-14: Propulsion Simulink Model ........................................................................ 47
Figure 3-15: Propulsion Throttle Gearing Simulink Model ............................................. 48
Figure 3-16: Engine Power Lag Flow Diagram .............................................................. 49
Figure 3-17: Engine Power Lag Time Constant Graph.................................................. 49
Figure 3-18: Engine Power Lag Simulink Implementation ............................................. 50
Figure 3-19: Engine Thrust Simulink Model .................................................................. 51
Figure 3-20: 6-DOF Equations of Motion Flow Diagram................................................ 54
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