Aerodynamics & Quadcopter Quick Start Welcome On-board Aerodynamics & Quadcopter Quick Start

/ Aerodynamics 101 Four Forces / Life Generation / Angle of Attack / Stall / Propeller

“ The important thing is not to stop questioning “ The important thing is not to stop questioning. Curiosity has its own reason for existing. One cannot help but be in awe when he contemplates the mysteries of eternity, of life, of the marvellous structure of reality. It is enough if one tries merely to comprehend a little of this mystery every day. Never lose a holy curiosity. ” - Albert Einstein

The Four Basic Forces http://www.daviddarling.info/encyclopedia/F/forces_of_flight.html

How does wing generate lift? The Neglected Fundamentals How does wing generate lift? https://www.youtube.com/watch?v=BPbOaf7Ef08

The Myth Leading Edge Trailing Edge http://iopscience.iop.org/article/10.1088/0031-9120/38/6/001/pdf The common misconception is that the air on top and below the aerofoil will meet again at the trailing edge.

Explanation 1 Keyword: Coandă effect, Bernoulli's principle https://youtu.be/aFO4PBolwFg

Explanation 2 https://youtu.be/CzD4zoxY0kE

Lift Generation But why? Fact 1: Air flow is deflected downwards – Newton’s 3rd Law Fact 2: Air on top of the wing travels faster - Bernoulli's Principle But why? Narrowing of the imaginary tunnels of the air flow

Lift Generation Believe at your own risk  Deduction 1: There is a equal and opposite upward force pushing the aerofoil up (hence lift!). Deduction 2: Faster travelling air on top exerts less pressure on the aerofoil, sucking the aerofoil upwards (hence lift!). Believe at your own risk 

✓ Which generates more lift? http://iopscience.iop.org/article/10.1088/0031-9120/38/6/001/pdf

? Lift vs Angle of Attack Angle of Attack ↑ = Lift ↑ http://iopscience.iop.org/article/10.1088/0031-9120/38/6/001/pdf

Stall – Breakdown of Lift Increased Drag Loss of Lift Increased Lift http://iopscience.iop.org/article/10.1088/0031-9120/38/6/001/pdf Observation 1: When AOA increases at small angle, lift (and also drag) increases

Great loss of lift and increase in drag. Increased Drag Loss of Lift Increased Lift http://iopscience.iop.org/article/10.1088/0031-9120/38/6/001/pdf Observation 2: When AOA increases until a certain angle (critical AOA), the airflow no longer follows the curvature of the aerofoil. Great loss of lift and increase in drag.

Stall – The Last Thing You Want in Flight

For those who interested… Flaps ( for landing, I’m sure you heard the sound of flaps deployment before  ) Winglet / Vortex Ground Effect Dihedral Vortex Ring State (never descend fast straight down!) …

? The Propeller – the rotating wing http://blog.oscarliang.net/how-to-choose-motor-and-propeller-for-quadcopter/ http://www.angelesflying.com/training/lesson2.html ? Why the pitch (AOA) is greater inwards

http://blog. oscarliang http://blog.oscarliang.net/how-to-choose-motor-and-propeller-for-quadcopter/ Diameter (inch) Pitch (inch) The inner region of the propeller travel less in a rotation, therefore “intuitively” needs a higher pitch.

The Propeller – CW & CCW

Take a Break! Recap: Next Session: How lift is generated (a more reasonable explanation). How lift can be increased. How lift can be destroyed (Stall). The propeller’s pitch Next Session: Principles of Motor and Electronic Speed Controller (ESC) Take a Break!

https://www. youtube. com/watch https://www.youtube.com/watch?v=ON0-DR2W22g&list=PLWoPr76-V4a_cJFwtEkywMDt53IHmiaFs&index=5 https://www.youtube.com/watch?v=Uzhs73xdq7I Post-production

/ Quadcopter 101 Principle Axis / Control Surfaces / Transmitter Modes / Flight Modes / Sensors / Pre- Flight

The Principle Axes – Roll, Pitch, Yaw http://blog.tkjelectronics.dk/2012/03/quadcopters-how-to-get-started/

The Principle Axes – Roll, Pitch, Yaw http://quadcopter101.blogspot.sg/2013_10_01_archive.html

Primary Control Surfaces http://www.aviation-history.com/theory/flt_ctl.htm

Primary Control “Surfaces” - Quadcopter http://copter.ardupilot.com/wiki/connect-escs-and-motors/ The control surfaces of a quadcopter is the propellers themselves!

Spinning Objects http://www.hk-phy.org/iq/helicopter/helicopter_e.html The spinning propeller / motor will turn the aircraft body in the Opposite direction

Primary Control “Surfaces” - Quadcopter Pitch Roll Throttle Yaw The speed (and hence the trust) of the propellers determines the attitude and movement of the quadcopter. http://www.socialledge.com/sjsu/index.php?title=File:CmpE244_S14_Quadcopter_Quad_motion1.JPG

Transmitter Modes http://blog.oscarliang.net/ctt/uploads/2013/10/stickmodes.jpg

Transmitter Modes https://www.wearechampionmag.com/quadcopter-transmitter-mode2-vs-mode1-difference

Flight Modes (and On-Board Sensors) Stabilised Mode ( scary Manual Throttle, not present in DJI drones) Altitude Hold Mode ( A-mode / P-ATTI ) Loiter Mode ( P-GPS / P-OPTI )

Accelerometer & Gyroscope Sensors Measures Acceleration (including gravitational acceleration) Measures Rate of Rotation

HOW Your orientation (attitude) in 3D space Acceleration Data (xyz) With Random Noise Mathematical Equations & Matrixes Which only crazy people understand Rate of Rotation Data (xyz) With Random Noise HOW do the sensors get the data? Your orientation (attitude) in 3D space Self-Correction (Roll / Pitch)

Magnetometer Sensor Measures Magnetic Field

Your Heading in 3D space Magnetic Field Direction Data (xyz) With Random Noise Mathematical Equations & Matrixes Which only smart people understand Your Heading in 3D space Self-Correction (Yaw)

Stabilised Mode Self-Correction (Roll / Pitch) Self-Correction (Yaw) (Manual) No ability to hover over a fixed position over the ground, No ability to maintain height (altitude)

Barometer Sensors Measures Atmospheric Pressure, and Translate to Altitude

Self-Correction (Throttle) Stabilised Mode (Manual) Altitude Data With Random Noise Self-Correction (Throttle) Altitude Hold Mode (A Mode / P-ATTI)

GPS Sensors Acquire 3-D Position & Time Weather-Dependent Prone to Interference Acquire 3-D Position & Time

Optical Flow Sensors Acquire 3-D Position, relative to the ground

https://www.mpg.de/research/nerve-cells-in-optic-flow https://youtu.be/WEerwSY_0TM Optical Flow (Vision Positioning System) works by comparing consecutive images and calculate pixel movements.

Altitude Hold Mode Loiter Mode Position Data (A Mode / P-ATTI) With Random Noise Self-Correction (Roll / Pitch) Loiter Mode (P-GPS Mode / P-OPTI Mode)

Sensors DO fail

Magnetic Field Distortion Source: Accurate Compassing in Harsh Environments Turning Effect Of A Current Carrying Coil In A Magnetic Field

“Compass Error” https://youtu.be/Lc4XpSgmR58 https://www.youtube.com/watch?v=Lc4XpSgmR58 https://youtu.be/Lc4XpSgmR58

“GPS Error” https://youtu.be/rV4-Kg4MK9U https://www.youtube.com/watch?v=rV4-Kg4MK9U https://youtu.be/rV4-Kg4MK9U

Least Number of Sensors Every Pilot Should Learn How to fly with Least Number of Sensors Master Stabilised / Altitude Hold Mode

Before Flight [IMPORTANT] Accelerometer Calibration by putting the Quadcopter on a flat surface during start-up. Compass Calibration by following instruction on screen (if needed). Ensure a good GPS Lock when flying outdoors, with clear sky. Always Get ready to switch back to Stabilised / Altitude Hold mode during emergency.

Gain Back Some Confidence https://www.youtube.com/watch?v=00BtVm9Qknw https://youtu.be/00BtVm9Qknw How to use IOC Course Lock | DJI PHANTOM 3 How to adjust Yaw Speed | DJI Phantom 3 | Gain and Expo

http://blog. maketheone http://blog.maketheone.com/dji-phantom-3-torn-down-before-taking-off-first-ever-phantom-3-live-anatomy/ http://blog.maketheone.com/dji-phantom-3-torn-down-before-taking-off-first-ever-phantom-3-live-anatomy/

Gyroscope & Accelerometer

GPS module, and probably Magnetometer

“Top 5 Drones you should buy” https://www.youtube.com/watch?v=q7cAO177bjo https://www.youtube.com/watch?v=_l6CQRHIGyg https://youtu.be/q7cAO177bjo

Copyright Concerns Use Royalty Free Resources, and never use copyrighted music or video clips Credit the Composer etc. and the end of your video

Timeline – Filming Request Inter-College Games – 13 Feb RC4ME Music Video – by 19 Feb RC4 Open Day Promotional Video – Feb? RC4 Open Day - March