If you need assistance, please send an email to forum at 4hv dot org. To ensure your email is not marked as spam, please include the phrase "4hv help" in the subject line. You can also find assistance via IRC, at irc.shadowworld.net, room #hvcomm.
Support 4hv.org!
Donate:
4hv.org is hosted on a dedicated server. Unfortunately, this server costs and we rely on the help of site members to keep 4hv.org running. Please consider donating. We will place your name on the thanks list and you'll be helping to keep 4hv.org alive and free for everyone. Members whose names appear in red bold have donated recently. Green bold denotes those who have recently donated to keep the server carbon neutral.
Special Thanks To:
Aaron Holmes
Aaron Wheeler
Adam Horden
Alan Scrimgeour
Andre
Andrew Haynes
Anonymous000
asabase
Austin Weil
barney
Barry
Bert Hickman
Bill Kukowski
Blitzorn
Brandon Paradelas
Bruce Bowling
BubeeMike
Byong Park
Cesiumsponge
Chris F.
Chris Hooper
Corey Worthington
Derek Woodroffe
Dalus
Dan Strother
Daniel Davis
Daniel Uhrenholt
datasheetarchive
Dave Billington
Dave Marshall
David F.
Dennis Rogers
drelectrix
Dr. John Gudenas
Dr. Spark
E.TexasTesla
eastvoltresearch
Eirik Taylor
Erik Dyakov
Erlend^SE
Finn Hammer
Firebug24k
GalliumMan
Gary Peterson
George Slade
GhostNull
Gordon Mcknight
Graham Armitage
Grant
GreySoul
Henry H
IamSmooth
In memory of Leo Powning
Jacob Cash
James Howells
James Pawson
Jeff Greenfield
Jeff Thomas
Jesse Frost
Jim Mitchell
jlr134
Joe Mastroianni
John Forcina
John Oberg
John Willcutt
Jon Newcomb
klugesmith
Leslie Wright
Lutz Hoffman
Mads Barnkob
Martin King
Mats Karlsson
Matt Gibson
Matthew Guidry
mbd
Michael D'Angelo
Mikkel
mileswaldron
mister_rf
Neil Foster
Nick de Smith
Nick Soroka
nicklenorp
Nik
Norman Stanley
Patrick Coleman
Paul Brodie
Paul Jordan
Paul Montgomery
Ped
Peter Krogen
Peter Terren
PhilGood
Richard Feldman
Robert Bush
Royce Bailey
Scott Fusare
Scott Newman
smiffy
Stella
Steven Busic
Steve Conner
Steve Jones
Steve Ward
Sulaiman
Thomas Coyle
Thomas A. Wallace
Thomas W
Timo
Torch
Ulf Jonsson
vasil
Vaxian
vladi mazzilli
wastehl
Weston
William Kim
William N.
William Stehl
Wesley Venis
The aforementioned have contributed financially to the continuing triumph of 4hv.org. They are deserving of my most heartfelt thanks.
Registered Member #618
Joined: Sat Mar 31 2007, 04:15AM
Location: Us-Great Lakes
Posts: 628
Wanting to take a brake from the SSTC control module design and programming that I was working, I wanted to try and finish a Quad-copter project I had started last year but somewhat gave up on due to issues, also while reading hack a day today I came across this article
and it made me think sure a lot of quad copters are out there and most are simply some hobby gyros and V-tail splitters, then there are the micro-controller based ones that use gyros and accelerometers to control the stability, so I was thinking why not try and be cray and see about making a quad be stabilized via a 3 axis gyro and a 3 axis accelerometer without the use of a uC.
The thing is I'm not certain on how to produce the 1ms-2ms on time pulse that is needed to control the speed controllers and have it be controlled via the analog signals coming from the accel and gyros, I was thinking a VCO but I'm not sure that it would adjust the duty cycle instead of the frequency.
Right now this is all just an idea, and theory but I think it would be kind of cool to make something like this and not use a uC.
Any suggestions on producing a voltage controlled duty cycle from 1-2ms on time?
Registered Member #27
Joined: Fri Feb 03 2006, 02:20AM
Location: Hyperborea
Posts: 2058
You need to have a look at control theory or you will depend on luck and lots of money to replace all the broken bits. Most simple ideas will be prone to bad oscillations that will end up in a crash with 100% certainty.
The exact same theory works on digital and analog so you are not saving any work or money by doing it the analog way, most likely the other way around. If you used tubes then you could claim EMP resistance, if not then you get all the drawbacks of analog with nothing to gain except the oddity of lagging behind by 30 years.
Registered Member #996
Joined: Sun Sept 09 2007, 06:17PM
Location: Canada
Posts: 16
Generate a triangular or sawtooth wave (doesn't matter - as long as it's linear) of the appropriate frequency and feed it into a comparator, comparing it with your reference voltage signal. Whenever the reference is higher than the linear waveform, the output of the comparator will be your "on" pulse. I did something similar in the controller/feedback loop of a boost converter for a school project using a few op-amps.
Registered Member #618
Joined: Sat Mar 31 2007, 04:15AM
Location: Us-Great Lakes
Posts: 628
Thanks Bjorn for pointing me towards the control theory link, I knew of control theory and am using a form of dynamic control for it, I was just trying to think of a way for the gyros and accelerometers to generate a signal that the motor controls could understand, and yes I figured it would be more costly since I'd have to purchase all the parts to perform the control functions and to incorporate the human interface.
I was just thinking about it as more of a off the beaten path and to have a bit more of a challenge, rather then just plugging all the sensors and human interface into a chip and having a single code do all the work, even though I still probably am just going to use the uC just because I already have it and I knew he code, I'd just have to work on the pid loops and adjust the mixing algorithm.
MNr, thanks for reminding me of the comparator method, I kept thinking I had to use a specialized chip.
This site is powered by e107, which is released under the GNU GPL License. All work on this site, except where otherwise noted, is licensed under a Creative Commons Attribution-ShareAlike 2.5 License. By submitting any information to this site, you agree that anything submitted will be so licensed. Please read our Disclaimer and Policies page for information on your rights and responsibilities regarding this site.
Remote control pulse controlled via Voltage, any suggestions?
