Between Sea and Sky: Aerial Aquatic Locomotion in Miniature Robots

Preface
Acknowledgements
Contents
Acronyms
List of Tables
Part I Breaking the Surface
1 Breaking the Surface
	1.1 Challenges
		1.1.1 Dry Flight
		1.1.2 Water Entry and Landing
		1.1.3 Submerged Movement
		1.1.4 Surface Movement
		1.1.5 Water Exit
		1.1.6 Wet Flight
	1.2 Multimodal Mobility and the Outdoor Environment
	1.3 Aerial-Aquatic Robots Presented in This Book
2 Why Swim and Fly?
	2.1 Motivation and Objectives
	2.2 Applications and Opportunities
		2.2.1 Remote Sensing
		2.2.2 Marine Conservation
		2.2.3 Micro-biology and Micro-plastic Analysis
		2.2.4 Pollution Monitoring
		2.2.5 Arctic Research
		2.2.6 Marine Wildlife
		2.2.7 Offshore Platform Maintenance
		2.2.8 Search and Rescue
		2.2.9 Extension of Operation Envelope of Cruises
		2.2.10 Bathymetric Mapping
	2.3 Aerial-Aquatic Robots as a Solution
3 Aerial-Aquatic Locomotion in Nature
	3.1 The Pelagic, Pleustonic and Littoral Environments
	3.2 Swimming in Aerial Animals
		3.2.1 Plunge Diving
		3.2.2 Pursuit Diving
		3.2.3 Diving Insects
	3.3 Flight in Aquatic Animals
		3.3.1 Flying Fish
		3.3.2 Flying Squid
		3.3.3 Sizing and Energetics
	3.4 Design Insights from Nature
		3.4.1 Wing Folding
		3.4.2 Plunge Diving
	3.5 Conclusion
4 Synthetic Aerial Aquatic Locomotion
	4.1 Multimodal Robots
	4.2 Aerial Water Sampling
	4.3 Seaplanes
	4.4 Rotary-Wing Vehicles
	4.5 Fixed-Wing
	4.6 Tilting Propeller configurations
	4.7 Flapping Wing Vehicles
	4.8 Possible Transition Methods Between Water and Air
5 The Physics of Aerial Aquatic Locomotion
	5.1 Resolving Contradictory Design Pressures
	5.2 Aerodynamics
	5.3 The Propulsion Problem
	5.4 Surface Hydrodynamics
	5.5 Water Jet Propulsion
	5.6 Plunge Diving
		5.6.1 Water Impact
Part II Practical Aerial Aquatic Locomotion
6 Aquatic Escape: Fast Escape with a Jet Thruster
	6.1 Compressed Gas Water Jet Thruster
	6.2 Water Jet Propulsion Theory
		6.2.1 Design Domain
	6.3 Prototype
		6.3.1 Valve Actuation
		6.3.2 Static Performance
	6.4 Underwater Takeoff Using a Jet Thruster
	6.5 Planar Trajectory Model
		6.5.1 Aerodynamics
		6.5.2 Longitudinal Stability
		6.5.3 Water Resistance
		6.5.4 Equations of Motion
	6.6 Take-Off Robustness
	6.7 Flight Components
	6.8 Aquatic Takeoff Performance
		6.8.1 Conclusion
7 Airframe Design for Plunge Diving
	7.1 Introduction
	7.2 The AquaMAV Airframe
		7.2.1 Control
		7.2.2 Propulsion
	7.3 Wind and Water Tunnel Measurements
		7.3.1 Water Tunnel Setup
		7.3.2 Results
	7.4 Performance Assessment
		7.4.1 Aerial Locomotion
		7.4.2 Aquatic Locomotion
		7.4.3 Summary of Performance
	7.5 Flight Test
8 Diving from Flight
	8.1 Planar Aerodynamics
		8.1.1 Underwater Motion
		8.1.2 Dive Trajectories - Aerial Phase
		8.1.3 Dive Trajectories - Aquatic Phase
		8.1.4 Model Assumptions
		8.1.5 Robot Performance
	8.2 System Dynamics Modelling and Simulation
		8.2.1 Simulated Vehicle Properties and Preliminary Considerations
	8.3 Modelling
		8.3.1 Aerodynamic Forces and Flight Phase
		8.3.2 Underwater Phase
		8.3.3 Air-Water Transitions
	8.4 Simulation Results and System Analysis
		8.4.1 Simulation of Different Phases
		8.4.2 System Dynamics: Aerial and Aquatic Operation
		8.4.3 Outlook: Analysis of Transition Phases
	8.5 Concluding Remarks on Simulation
9 Aquatic Escape: Repeatable Escape with Combustion
	9.1 Water Reactive Chemistry
		9.1.1 Combustion
		9.1.2 Solid Reactants as a Combustion Gas Source
	9.2 Simulation and Validation with Fixed Experiment
		9.2.1 Physics of Jet-Gliding
		9.2.2 Model-Based Design
		9.2.3 Static Modelling
	9.3 Design of an Aquatic Jump-Glider
		9.3.1 Robot Design
		9.3.2 Principle of Operation
		9.3.3 Systems
		9.3.4 Wing Design and Stability
	9.4 Cyclic Aquatic Escape with Jet Propulsion
		9.4.1 Controlled Conditions
		9.4.2 Outdoor Conditions
		9.4.3 Wave Tolerance
10 Efficient Water-Air Propulsion with a Single Propeller
	10.1 Introduction
	10.2 Computational Investigations
	10.3 Experimental Verification
		10.3.1 Results and Analysis
	10.4 Aerial-Aquatic Locomotion
		10.4.1 Gearbox Mechanism
		10.4.2 Prototype
11 Sailing and Flying with a Multimodal Robot
	11.1 The Challenges of Surface Locomotion
		11.1.1 Cycle
		11.1.2 Hybrid Sizing
		11.1.3 Propeller-Powered Takeoff
	11.2 Harnessing the Wind
	11.3 Design
		11.3.1 Morphology Change Actuation
	11.4 Avionics
		11.4.1 Wind Sensing
	11.5 Aerodynamics Surfaces
		11.5.1 Wings
		11.5.2 Sails
		11.5.3 Tail
		11.5.4 Numerical Simulation Results
	11.6 Hydrodynamics
		11.6.1 Hydrodynamics Validation
	11.7 Onboard Control and Autonomy
		11.7.1 PX4
		11.7.2 Dual-Mode Configuration
		11.7.3 Flying
		11.7.4 Sailing
	11.8 Operation of a Sailing-Flying Robot
		11.8.1 Transition from Water to Flight
		11.8.2 Sailing
	11.9 Characterisation
		11.9.1 Comparison with the AquaMAV: Wing Morphing
12 Multirotor Aircraft and the Aquatic Environment
	12.1 Introduction to MEDUSA
	12.2 Design
		12.2.1 Operation Principle and Envelope
		12.2.2 Deployment Flying Vehicle
	12.3 Sensing and Control
		12.3.1 Horizontal Actuation and Buoyancy Control
		12.3.2 Sensor Payload
		12.3.3 Electronics, Communication and Inter-System Tether
	12.4 Results and Discussion
		12.4.1 Membrane-Based Actuation
		12.4.2 Vertical Locomotion and Control
		12.4.3 Horizontal Locomotion
		12.4.4 Outdoor Testing
	12.5 Conclusions
13 Practical Tips for Building Aerial-Aquatic Robots
	13.1 High-Speed Actuation
	13.2 High-Torque Actuation
		13.2.1 The Morphing Case
	13.3 Battery
	13.4 Ignition
	13.5 Waterproof Openings
	13.6 Composite Construction for Aerial-Aquatic Robots
		13.6.1 Prepreg
		13.6.2 Woven Wet Lay-Up for Wings
	13.7 Launcher Testing Apparatus
	13.8 Sensing Options for MAVs
14 Conclusion
	14.1 Summary
	14.2 Lessons Learned
	14.3 How Far Have We Come?
	14.4 Impact of Aerial-Aquatic Robotics in the World
		14.4.1 Environmental Science
		14.4.2 Emergency Response
	14.5 Technological Trends and Future Work
	14.6 Concluding Remarks
Appendix  References