Optimizing small multi-rotor unmanned aircraft : a practical design guide

Content: Introduction 2 Lithium Polymer battery (power supply) 2.1 Safety considerations 2.2 Lithium Polymer discharge characteristics 3 Electronic Speed Controller (ESC) 3.1 Timing 3.2 Cut-off voltage 3.3 Switching frequency 4 The Brushless DC (BLDC) motor (outrunner) 4.1 BLDC motor construction and theory 4.2 Equivalent brushed DC motor equations 4.3 Comparing theoretical and empirical data 5 The propeller (rotor) 5.1 Propeller or rotor? 5.2 Propeller variables 5.3 Propeller geometry 5.4 Simple momentum theory 5.5 Non-dimensional rotor (propeller) coefficients 5.6 Figure of Merit (FM) 5.7 Propeller efficiency (p) 5.8 Co-axial and overlapping rotor designs 5.9 Reynolds number, Re 5.10 Airfoil geometry 5.11 Airfoil theory - Blade Element Theory (BET) 5.12 Online airfoil resources 6 The system solution 6.1 IMechE UAS challenge - a worked multi-rotor example 6.2 Measuring the propulsive efficiency 6.3 Forward flight 6.4 Dihedral and cant angles 6.5 Active thrust vectoring 7 Conclusion 7.1 Economic and societal impact 7.2 Future directions, opportunities and threats AppendicesAppendix A1 Li-Po batteries ready reckoner (6S) Appendix A2 A range of 6S Li-Po batteries with high specific energy (Wh/kg) (June 2018) Appendix B Guidance on the safe use, handling, storage and disposal of Lithium Polymer batteries Appendix C T-Motor BLDC motor selection tool Appendix D Overall system selection spreadsheet Appendix E Examples of multi-rotor systems built at the ASL Appendix F Drone radio frequency legal requirements in the UK Appendix G Example Pixhawk flight controller wiring diagram and mission planner set-up (PID tuning)