Difference between revisions of "Multi-rotor"

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(some BLDC information, etc.)
(more brushless DC information)
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It appears that most modern small electric aircraft use so-called "brushless DC motors", each one driven by its own "BLDC ESC". (These are easily recognized -- BLDC motors have exactly 3 equally-fat wires that go into them, which come from the BLDC ESC -- as opposed to most electric aircraft a few years ago, which used brushed DC motors with exactly 2 equally-fat wires).
 
It appears that most modern small electric aircraft use so-called "brushless DC motors", each one driven by its own "BLDC ESC". (These are easily recognized -- BLDC motors have exactly 3 equally-fat wires that go into them, which come from the BLDC ESC -- as opposed to most electric aircraft a few years ago, which used brushed DC motors with exactly 2 equally-fat wires).
  
While it is probably not cost-effective to build your own BLDC motor or BLDC ESC, many of us are insatiably curious about what goes on inside these things, and so:
+
While it is probably not cost-effective to build your own BLDC motor or BLDC ESC, many of us are insatiably curious about what goes on inside these things, and so build one anyway:
 
* [http://en.wikipedia.org/wiki/brushless_DC_electric_motor Wikipedia: brushless DC electric motor]
 
* [http://en.wikipedia.org/wiki/brushless_DC_electric_motor Wikipedia: brushless DC electric motor]
* [http://www.atmel.com/dyn/resources/prod_documents/doc8012.pdf Atmel AVR444: Sensorless control of 3-phase brushless DC motors] using ATmega48 (also works without change for ATmega88 and ATmega168)
+
* [http://www.atmel.com/dyn/resources/prod_documents/doc8012.pdf Atmel AVR444: Sensorless control of 3-phase brushless DC motors] using ATmega48 (also works without change for ATmega88 and ATmega168). Assumes you've already read [http://www.atmel.com/dyn/resources/prod_documents/doc2596.pdf Atmel AVR443: Sensor-based control of three phase Brushless DC motor]
 
* [http://www.atmel.com/dyn/resources/prod_documents/doc8138.pdf AVR194: Brushless DC Motor Control using ATmega32M1]: BLDC motor control application using Hall effect position sensors to control commutation sequence.
 
* [http://www.atmel.com/dyn/resources/prod_documents/doc8138.pdf AVR194: Brushless DC Motor Control using ATmega32M1]: BLDC motor control application using Hall effect position sensors to control commutation sequence.
 
* [http://www.mikrokopter.de/ucwiki/BrushlessCtrl MikroKopter: brushless motor controller] was designed to give lower latency than off-the-shelf PWM ESCs.
 
* [http://www.mikrokopter.de/ucwiki/BrushlessCtrl MikroKopter: brushless motor controller] was designed to give lower latency than off-the-shelf PWM ESCs.
 +
* [http://www.openservo.com/forums/viewtopic.php?t=972 OpenServo: Brushless DC Servo] "The thing that will make our board different from other ESC's is that we are closing the feedback loop with a ... outside position reference."
  
 
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Revision as of 07:43, 20 April 2010

A multi-rotor helicopter is a flying vehicle with more than one rotor.

The nice people at http://www.quadheli.com/ have asked for our help designing and building a multi-rotor helicopter.

Several people are using small unmanned helicopters with 4 rotors ("quadheli" or "quadcopter").

goals

motors and propellers

frame

camera

electronics

testing

BLDC

It appears that most modern small electric aircraft use so-called "brushless DC motors", each one driven by its own "BLDC ESC". (These are easily recognized -- BLDC motors have exactly 3 equally-fat wires that go into them, which come from the BLDC ESC -- as opposed to most electric aircraft a few years ago, which used brushed DC motors with exactly 2 equally-fat wires).

While it is probably not cost-effective to build your own BLDC motor or BLDC ESC, many of us are insatiably curious about what goes on inside these things, and so build one anyway:

unsorted

way too many links here. Please delete the ones not relevant to multi-rotor helicopters.

  • Wikipedia: quadrotor is a nice introduction. But what are these "three rotor craft" it mentions? (TriCopter? Tri-copter?)
  • The Gluonpilot wiki (autopilot) mentions "Quadrocopter" [1]
  • MikroKopter wiki [2] semi-open-source "for noncommercial use"
  • QC-Copter Wiki [3] : updates all motor speeds at 500 Hz.
  • QuadroCopter Wikia [4]
  • ARM-o-Kopter wiki [5]
  • DIYdrones: "There are a zillion quad- and tri-copters out there" [6]
  • DIYdrones: Quadcopters discussion forum [7]
  • DIYdrones: Return to Home Quadrocopter (UAVX) [8]
  • DIYdrones: "There are loads of open source quadcopters out there, but they're all ..." [9] Is it possible to design a helicopter that avoids this problem?
  • the "ChRoMicro - Cheap Robotic Microhelicopter HOWTO" [10], [11] describes "how to build a 300 g helicopter with embedded Linux and Bluetooth datalink from off-the shelf components for less than 500 EUR." Can these ideas be adapted to helicopters with more rotors?
  • Quadrotto: Project Quadcopter [12], [13]. Is there any way to avoid making the same mistakes all over again, and instead make fresh new mistakes? :-).
  • RCgroups: Multi Rotor Helis discussion forum [14]
  • microdrones [15]
  • whatnick blog: "quadcopter taking shape"; and other quadcopter posts ... he apparently has a Gumstix Verdex and a BeagleBoard -- are either one of these going on the quadcopter?
  • WSN wiki: wireless sensor node platforms -- perhaps we could use one of these boards for our wireless communication, or perhaps make incremental improvements, rather than designing yet another one from scratch?
  • Dr. Igor Bensen designed the eight rotor helicopter on the front page of Popular Mechanics 1982 September.
  • "Real-time+stabilization+of+an+eight-rotor+UAV+using+optical+flow" Google: "Real-time stabilization of an eight-rotor UAV using optical flow"