Unmanned Rotorcraft Systems

✍ Scribed by Cai, Guowei

• Publisher: Springer London
• Year: 2011
• Tongue: English
• Leaves: 282
• Series: Advances in Industrial Control
• Category: Library

✦ Synopsis

An unmanned aerial vehicle (UAV) is an aircraft that is equipped with necessary data processing units, sensors, automatic control and communications systems, and is capable of performing autonomously flight missions without a human pilot. Unmanned Rotorcraft Systems provides a complete treatment of the design of fully autonomous miniature rotorcraft UAVs. It is an integration of advanced technologies developed in communications, computing and control areas. In particular, it focuses on:

-the systematic hardware construction;

-software systems integration;

-aerodynamic modeling; and

-automatic flight control system design.

Emphasis is extended to the cooperative control and flight formation of multiple UAVs, and vision-based ground target tracking and landing on moving platforms. Other issues such as the development of GPSless indoor micro aerial vehicles and vision-based navigation are also highlighted.

The proposed monograph aims to explore the research and development of fully functional miniature UAV (unmanned-aerial-vehicle) rotorcraft. This consists of a small-scale basic rotorcraft with all necessary accessories onboard, and a ground station. The unmanned system is an integration of advanced technologies developed in communications, computing and control areas. It is an excellent testing ground for trialing and implementing modern control techniques. It is however a highly challenging process. The aerodynamics of a small-scale rotorcraft such as a hobby helicopter are similar to its full-scale counterpart but has some unique characteristics, such as the utilization of stabilizer bar and higher main/tail rotors rotation speed. Besides these, the strict limitation on payload also increases the difficulty on upgrading a small-scale rotorcraft to a UAV with full capacities. Based on its various characteristics and limitations, a light-weight but effective onboard computer system with corresponding onboard/ground software should be carefully designed to realize the system identification and automatic flight requirements. These issues will be addressed in detail in this monograph. Research on the following will be detailed:

-utilizing the vision-based system for accomplishing ground target tracking;

-attacking and landing;

-cooperative control and flight formation of muitiple unmanned rotorcraft;

-future research directions on the related areas.

The book will be a good reference for researchers and students working on the related subjects. Unmanned Rotorcraft Systems will be of great value to practicing engineers in rotorcraft industries and to researchers in areas related to the development of unmanned systems in general. It may be used as a reference for advanced undergraduate and graduate students in aeronautics and astrinautics, electrical and mechanical engineering.

✦ Table of Contents

11.3 Camera Calibration......Page 3
10.3 Collision Avoidance......Page 6
11.4 Vision-Based Ground Target Following......Page 8
10.4 Flight Test Results......Page 10
11.4.2 Image Tracking......Page 14
Cover......Page 1
11.2 Coordinate Frames Used in Vision Systems......Page 2
Preface......Page 9
Contents......Page 11
11.4.1.4 Pattern Recognition......Page 13
Abbreviations......Page 15
6.3.2.1 CG Location Determination......Page 16
6.3.2.2 Measurement of Inertia Moment......Page 17
11.4.2.3 Mean Shift-Based Image Tracking......Page 18
4.3.2.2 3D Drawing......Page 19
Unmanned Rotorcraft Systems......Page 4
11.3.2 Intrinsic Parameter Estimation......Page 5
Series Editors' Foreword......Page 7
8.4 Performance Evaluation......Page 12
1.1 Introduction......Page 20
1.2 Brief History of Rotorcraft......Page 21
11.4.3 Target Following Control......Page 22
9.4 Simulation and Flight Test Results......Page 23
1.3.4 Ground Control Station......Page 30
6.4 Model Validation......Page 31
1.4.2 Ground Control Station Software Structure......Page 32
11.4.3.1 Control of the Pan/Tilt Servo Mechanism......Page 24
1.3.2.2 Navigation Sensors......Page 28
1.3.2.3 Fail-Safe Servo Controller and Wireless Links......Page 29
1.3.1 RC Rotorcraft......Page 25
1.3.2.1 Avionic Processing Stack......Page 27
1.5.1 First-Principles Approach......Page 33
1.5.2 System and Parameter Identification......Page 34
1.7 Application Examples......Page 35
Scientific Exploration......Page 36
Engineering and Construction......Page 37
1.8 Preview of Each Chapter......Page 38
2.2 Coordinate Systems......Page 41
2.2.1 Geodetic Coordinate System......Page 42
2.2.2 Earth-Centered Earth-Fixed Coordinate System......Page 43
2.2.3 Local North-East-Down Coordinate System......Page 44
2.2.5 Body Coordinate System......Page 45
2.3.1.1 Euler Rotations......Page 46
2.3.1.2 Euler Angles......Page 47
2.3.1.3 Angular Velocities......Page 49
2.3.2.3 Geodetic and Vehicle-Carried NED Coordinate Systems......Page 50
2.3.2.4 Vehicle-Carried NED and Body Coordinate Systems......Page 51
2.3.2.5 Local and Vehicle-Carried NED Coordinate Frames......Page 52
3.1 Introduction......Page 53
3.3 Hardware Components Selection......Page 54
3.3.1 RC Helicopter......Page 55
3.3.2 Flight Control Computer......Page 57
3.3.3 Navigation Sensors......Page 58
3.3.5 Fail-Safe Servo Controller......Page 60
3.3.6 Wireless Modem......Page 61
3.3.8 Vision Computer......Page 62
3.3.9 Vision Sensor......Page 63
3.3.11 Servo Mechanism......Page 64
3.3.13 Manual Control......Page 65
3.4.1 Layout Design......Page 66
3.4.3 Power Supply Design......Page 70
3.4.4 Shielding Design......Page 71
4.1 Introduction......Page 76
4.2.1 Framework Design......Page 77
4.2.2 Task Management......Page 79
4.2.2.1 Task Scheduling......Page 80
4.2.2.3 Time Allocation......Page 81
4.2.3 Implementation of Automatic Control......Page 83
4.2.4 Emergency Handling......Page 86
4.2.5 Vision Processing Software Module......Page 88
4.3 Ground Control Station Software......Page 89
4.3.1 Framework of Ground Station Software Module......Page 90
4.3.2.1 3D Model Development......Page 93
4.3.2.2 3D Drawing......Page 94
4.3.2.3 3D View......Page 95
4.4 Software Evaluation......Page 96
5.1 Introduction......Page 99
5.2 Extended Kalman Filtering......Page 100
5.3.1 AHRS Dynamics Model......Page 102
5.3.2 INS Dynamics Model......Page 104
5.4 Design of Extended Kalman Filters......Page 105
5.4.1 EKF for AHRS with Accelerometer Measurement......Page 106
5.4.2 EKF for AHRS with Magnetometer Measurement......Page 107
5.4.3 EKF for INS......Page 108
5.5 Performance Evaluation......Page 109
6.1 Introduction......Page 113
6.2.1 Kinematics......Page 114
6.2.2 Rigid-Body Dynamics......Page 117
6.2.2.1 Main Rotor Force and Moment......Page 118
6.2.2.2 Tail Rotor Force and Moment......Page 120
6.2.2.3 Fuselage Forces......Page 121
6.2.2.5 Horizontal Fin Force and Moment......Page 122
6.2.3.1 Stabilizer Bar Dynamics......Page 123
6.2.3.2 Bare Main Rotor......Page 124
6.2.3.3 Complete Main Rotor Flapping Dynamics......Page 125
6.2.4 Yaw Rate Feedback Controller......Page 126
6.3.1 Direct Measurement......Page 127
6.3.2.1 CG Location Determination......Page 128
6.3.2.2 Measurement of Inertia Moment......Page 129
6.3.2.3 Airfoil Deflection Test......Page 130
6.3.2.4 Collective Pitch Curve Examination......Page 132
6.3.3 Estimation Based on Wind-Tunnel Data......Page 134
6.3.4.2 Frequency Sweeping......Page 135
6.3.5 Fine Tuning......Page 142
6.4 Model Validation......Page 143
6.5 Flight Envelope Determination......Page 144
7.1 Introduction......Page 152
7.2 Hinfty Control Technique......Page 153
7.3 Inner-Loop Control System Design......Page 159
7.3.1 Model Linearization......Page 160
7.3.2 Problem Formulation......Page 161
7.3.3 Selection of Design Specifications......Page 163
7.3.4 Hinfty Control Law......Page 164
7.3.5 Performance Evaluation......Page 166
8.1 Introduction......Page 176
8.2 Robust and Perfect Tracking Control......Page 177
i. State Feedback Case......Page 178
ii. Full-Order Measurement Feedback Case......Page 179
iii. Reduced-Order Measurement Feedback Case......Page 180
8.3 Outer-Loop Control System Design......Page 181
8.4 Performance Evaluation......Page 187
9.1 Introduction......Page 194
9.2.1 Depart/Abort (Forward Flight)......Page 195
9.2.3 Depart/Abort (Backward Flight)......Page 196
9.2.5 Vertical Maneuver......Page 197
9.2.6 Lateral Reposition......Page 198
9.2.7 Turn-to-Target......Page 199
9.2.9 Pirouette......Page 200
9.2.10 MTE Concatenation......Page 201
9.4 Simulation and Flight Test Results......Page 216
10.1 Introduction......Page 219
10.2.1 Coordinate Systems in Formation Flight......Page 221
10.2.2 Kinematics Model......Page 223
10.3 Collision Avoidance......Page 224
10.4 Flight Test Results......Page 228
11.1 Introduction......Page 236
11.2 Coordinate Frames Used in Vision Systems......Page 237
11.3 Camera Calibration......Page 238
11.3.1 Camera Model......Page 239
11.3.2 Intrinsic Parameter Estimation......Page 240
11.3.3 Distortion Compensation......Page 242
11.3.4 Simplified Camera Model......Page 243
11.4.1.1 Segmentation......Page 244
11.4.1.2 Feature Extraction......Page 246
11.4.1.3 Object Representation......Page 248
11.4.2 Image Tracking......Page 249
11.4.2.1 Model-Based Image Tracking......Page 250
11.4.2.3 Mean Shift-Based Image Tracking......Page 253
11.4.2.4 Supervisor......Page 255
11.4.2.5 Experimental Verification of Target Detection and Visual Tracking......Page 256
11.4.3 Target Following Control......Page 257
11.4.3.1 Control of the Pan/Tilt Servo Mechanism......Page 259
11.4.3.2 Following Control of the Unmanned Aerial Vehicle......Page 263
11.5 Experimental Results......Page 264
References......Page 268
Index......Page 276