Revision as of 16:35, 27 September 2012

Unmanned Aerial Vehicle

This TED talk gives a good intro to quad rotors. These are small UAVs that use four rotors for easy flight control. This project will design and build a small quad rotor.

Interested Members

If you're interested in working on this please add yourself to the following list:

• NickRyder
• Dwarr
• caroline
• Fang Fang Hu (who will make an account later) - has experience using Android to remote-control stuff; maybe useful for if we want phones to control the UAV.
• crouchingbadger

Background/Research

There are some quadcopter kits around. These include:

• http://aeroquad.com/ ($200 kit)
• http://code.google.com/p/arducopter/ ($500 kit)

and some interesting quadcopter home-grown projects...

• http://letsmakerobots.com/node/23926
  Not finished, some links on parts, but the HW looks nice.
• http://radio-commande.com/international/triwiicopter-design/
  Tri-coopter, uses Wii gyro & accels, and mini Arduion + open source sw on http://code.google.com/p/multiwii/source/browse/#svn%2Ftags

• The openpilot.org has links to many airframes
  http://wiki.openpilot.org/display/Doc/Example+Airframes

and more....
http://letsmakerobots.com/node/30408

Going through a few dozen of the quadcopter designs I found that the most popular and reasonably cheap parts that we could consider are the following.

Motors

http://www.rctimer.com/index.php?gOo=goods_details.dwt&goodsid=120&productname=
1300Kv, 240W, 11$

or this one http://www.hobbyking.com/hobbycity/store/uh_viewItem.asp?idProduct=4701
1050kv, $12.42

It was hard to source these parts in the UK, so we went for the Robot Birds site.

Method for choosing motors: look at the specs for a motor that's known to work, then try to find something similar.

Motor known to work: hexTronik 24gram Brushless Outrunner 1300kv.

Comparable motor (vaguely): BL Motor A2822(2208) 1100Kv, should produce ~300 g thrust each.

ESC

http://www.hobbypartz.com/07e-skywalker-20a.html
20A $9.50

or preferably this one http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=6457
18A $7.15

Planned ESC: http://robotbirds.com/catalog/product_info.php?cPath=3_321&products_id=1378
20A £8

Propellers

http://www.rctimer.com/index.php?gOo=goods_details.dwt&goodsid=512&productname=
EPP1045, counter rotating propellers set 2x254 mm, $2.95

http://robotbirds.com/catalog/product_info.php?cPath=42_78&products_id=6172
Paired props, £2.25

Battery

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9185
Lipo 4Ah 337g $26

or slightly weaker but much cheaper http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=7636
Lipo 2.2Ah 173g $8.99

Controller

Mini Arduino board to start with https://www.sparkfun.com/products/11113? and later on a custom PCB with some atmega depending on the experience and requirements for the future.
A very cheap alternative could be MSP430 LaunchPad dev board from TI for $4.30. It runs MSP430 and I belive it would have enough power to drive everything we need. It's programmed via USB. http://www.ti.com/tool/msp-exp430g2#buy

Design

Overview

The UAV needs a flight computer that can determine the UAV's motion and control the rotors to allow the UAV to hover in a stable location and move to desired locations. The flight computer will probably use an accelerometer, a gyro and some range finders to measure the motion and current location. The flight computer will then use this information to calculate and set the required rotor speeds. Additionally the flight computer should have some wireless communication method to receive instructions.

progress on 19th July 2012

progress on 19th July 2012

progress on 24th July 2012

Parts list

These are the kinds of parts we'll probably need:

• Microcontroller to be used as flight computer We could use an arduino or mbed for prototyping
• 4 small motors
• 4 motor controllers?
• 4 sets of rotor blades
• 3 axis accelerometer chip
• gyro chip
• ultrasound range finder?
• wireless communcation method. An Xbee might be good.
• Mechanical frame

http://aeroquad.com/showwiki.php?title=Recommended+components+for+your+AeroQuad has some helpful information about necessary parts.

Regulations

There are some regulations about UAV flights that can be found at [1]. This refers a lot to CAP393

Kit people have

• Gyro and accelerometers - George
  - The gyro is single axis LY530A http://pdf1.alldatasheet.com/datasheet-pdf/view/346183/STMICROELECTRONICS/LY530AL.html
  - Accelerometer 3D LIS331DLM http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATASHEET/CD00213611.pdf
• arduino and mbed - Nick
• wii accelerometer (for testing code) - Nick
• lilypad + accelerometer + stuff - Caroline
• DC motors - Caroline
• Lego - (the other) George
• Bits of aluminium extrusion for the frame - Phil

Testing

Kit to buy for first test

1x Motor: http://robotbirds.com/catalog/product_info.php?products_id=4525 £9.95

1x ESC: http://robotbirds.com/catalog/product_info.php?cPath=3_321&products_id=1378 £7.80

1x 10 inch Prop pair: http://robotbirds.com/catalog/product_info.php?cPath=42_78&products_id=6172 -- worry: are these too large? £2.25

1x 4 inch Prop pair: http://robotbirds.com/catalog/product_info.php?cPath=42_78&products_id=5669 75p

Nick has ordered these. The total cost, including postage was £24.25.

• Nick has currently paid £10
• David will pay £5 - PAID 23Aug2012
• Jiri will pay £5
• Jamie will pay £5 - PAID 06Sep2012

If you are interested in the project and are willing to chip in towards these costs please let Nick know.

Does any of us have a voltage source to take the place of the LiPo battery during testing? If not, we should probably buy a cell. NOTE: plan is to use a UPS that Jiri will hopefully bring.

The kit has arrived. We've had a poke at it but we need some female bullet connectors for the ESC and a power supply.

Kit bought after first test

3x Motor

3x ESC

1x 10 inch Prop pair

We need to settle on a combination LiPo cells and charger, then buy that.