Safety and Reliability in Cooperating Unmanned Aerial Systems

Contents......Page 8
Preface......Page 6
1. Introduction......Page 12
1.1 Unmanned Aerial Systems......Page 13
1.2 Cooperative Control......Page 14
1.3 Contingencies......Page 17
1.3.1 Faults and failures of UAV components......Page 18
1.3.3 Information flow faults......Page 19
1.3.4 Team anomalies and collisions......Page 20
1.3.5 Environmental effects......Page 21
1.3.6 Book overview......Page 22
2. Health Management for the Individual Vehicle: A Review......Page 24
2.1 Passive and Active Fault-Tolerant Control Systems......Page 25
2.2 Fault/Failure Detection and Diagnosis......Page 27
2.3 Control Reconfiguration......Page 28
2.4 FTC and FDD Techniques for MAV and SUAV......Page 30
3. Health Monitoring and Adaptation for UAS Formations......Page 32
3.1 Models of Vehicle Dynamics, Flight Control, and Faults......Page 36
3.1.1 ALTAV dynamics and control......Page 37
3.1.2 Quadrotor dynamics and control......Page 40
3.1.3 Actuator faults......Page 42
3.2 Formation Control......Page 44
3.2.1 Elements of contraction theory......Page 46
3.2.2 Simplified modeling for the purpose of formation control synthesis......Page 48
3.2.3 Formation control objective......Page 53
3.2.4 Closed-loop representation of the formation......Page 54
3.2.5 Convergence analysis of state trajectories......Page 59
3.2.6 Modeling a formation of UAVs with realistic nonlinear dynamics......Page 68
3.2.7 Trajectory of the leader and obstacle/threat avoidance......Page 69
3.2.8 Formation control design algorithm......Page 71
3.3.1 Context......Page 72
3.3.2 Simplified model of vehicle closed-loop dynamics......Page 73
3.3.3 Concept of observer with disturbance attenuation......Page 76
3.3.4 Synthesis of DAFD......Page 80
3.3.5 Threshold selection......Page 88
3.3.6 DAFD design algorithm......Page 90
3.4.1 Context......Page 91
3.4.2 Networked information and coupling effects......Page 92
3.4.3 Estimator of heading angle......Page 96
3.4.4 Statistical test for DNaFD......Page 97
3.4.5 DNaFD design algorithm......Page 100
3.5 UAV Command Adaptation......Page 101
3.6 Simulations and Experiments......Page 104
3.6.1 Formation control of unicycles......Page 105
3.6.2 Formation control of quadrotor aircraft......Page 113
3.6.3 DAFD and formation control of ALTAVs......Page 115
3.6.4 DAFD and quadrotor formation control......Page 123
3.6.5 DNaFD and formation control of ALTAVs......Page 126
3.6.5.1 Simulations exempt from environmental effects......Page 127
3.6.5.2 Simulations with environmental effects......Page 132
3.6.6 Decentralized fault detection for mixed-type, concurrent actuator faults......Page 134
3.6.7 DAFD/DNaFD in closed loop with individual vehicle FDD system......Page 137
3.6.8 A note on the digital implementation......Page 140
4. Decision Making and Health Management for Cooperating UAS......Page 142
4.1.1 Context......Page 145
4.1.2 Related work......Page 148
4.1.3 Multi-formations......Page 149
4.1.4.1 Cooperating UAS and urban environment......Page 151
4.1.4.2 Measurements......Page 156
4.1.4.3 Feasible paths......Page 158
4.1.4.4 Communication network......Page 161
4.1.5 UAS-threat encounters modeled as Markov decision processes......Page 163
4.1.6 Problem formulation......Page 167
4.1.7 Decision policies: perfect information......Page 171
4.1.8 Decision policies: partially known environment......Page 175
4.1.8.1 Information state estimation......Page 176
4.1.8.2 Rollout policy......Page 179
4.1.8.3 Computational load......Page 182
4.1.9.1 Perfect information......Page 184
4.2.1 Context......Page 185
4.2.2 Impact of information ow fault on UAS decision policies......Page 186
4.2.3 Health state estimation......Page 188
4.2.4 Distributed computations of W0 k;Pi;E; j......Page 193
4.3.1.1 Low-level health threat......Page 195
4.3.1.2 High-level health threat......Page 199
4.3.2 Sequence of targets and perfect knowledge of environment......Page 202
4.3.3 The case of perturbed MDPs......Page 204
4.3.4 Successive zones of surveillance in partially known environment......Page 208
4.3.5 Information flow faults......Page 210
4.4.1 Context......Page 211
4.4.2 Architecture......Page 212
4.4.3 Distributed and parallel simulation environment......Page 213
4.4.4 Experiments......Page 215
Bibliography......Page 218
Index......Page 232