Go to Post I also like how the FTC folks are able to get involved with the FRC process this year, but it's always a bit of a let down when you're told you can't launch things into the air. - s_forbes [more]
Home
Go Back   Chief Delphi > Technical > Electrical
CD-Media   CD-Spy  
portal register members calendar search Today's Posts Mark Forums Read FAQ rules

 
Closed Thread
Thread Tools Rate Thread Display Modes
  #16   Spotlight this post!  
Unread 13-07-2012, 17:33
Michael Hill's Avatar
Michael Hill Michael Hill is online now
Registered User
FRC #3138 (Innovators Robotics)
Team Role: Mentor
 
Join Date: Jul 2004
Rookie Year: 2003
Location: Dayton, OH
Posts: 1,580
Michael Hill has a reputation beyond reputeMichael Hill has a reputation beyond reputeMichael Hill has a reputation beyond reputeMichael Hill has a reputation beyond reputeMichael Hill has a reputation beyond reputeMichael Hill has a reputation beyond reputeMichael Hill has a reputation beyond reputeMichael Hill has a reputation beyond reputeMichael Hill has a reputation beyond reputeMichael Hill has a reputation beyond reputeMichael Hill has a reputation beyond repute
Re: Sensors

When it comes to encoders, a quadrature encoder is particularly useful. If you take a normal (not magnetic, but light-based) encoder apart, you'll find a light source, an "encoder wheel" with a bunch of holes and a light sensor. Basically, the light shines through the holes. When the wheel spins, the receiver counts how many holes have been seen. Normally, the light sensor can't tell if the wheel is spinning forward or backward, but a quadrature encoder has another light sensor and another set of holes on the wheel that are offset from the first set. There are four distinct "states" the encoder can be in, so it knows if it's counting up or down.
  #17   Spotlight this post!  
Unread 13-07-2012, 22:31
Kevin Selavko's Avatar
Kevin Selavko Kevin Selavko is offline
Registered User
AKA: Voltonless
FRC #3260 (SHARP)
Team Role: Electrical
 
Join Date: Jan 2012
Rookie Year: 2008
Location: Beaver PA USA
Posts: 155
Kevin Selavko is on a distinguished road
Re: Sensors

Quote:
Originally Posted by Gdeaver View Post
$40 and an Arduino will get you a 3 axis accelerometer and Gyro that can give you pitch, yaw and roll. As was mentioned the yaw is going to drift over time. 6 axis IMU's have improved allot. Our team is going to work with them this fall. Maybe we can get field centric drive working. If we could only firure out how to get a magnetometer working on the bot, neat things could be done. All those magnetic fields put the damper on them. An IMU is what is needed for good bridge balancing.
So magnetometers don't work well on the robots?
__________________
Team SHARP
Pittsburgh Regional Champions 2014
Vex Pittsburgh Excellence Award 2014
Vex Pittsburgh Champions 2014
Vex Maryland Champions 2014
Pittsburgh Regional Finalists 2013
Buckeye Regional Finalists 2013
  #18   Spotlight this post!  
Unread 14-07-2012, 08:23
Gdeaver Gdeaver is offline
Registered User
FRC #1640
Team Role: Mentor
 
Join Date: Mar 2004
Rookie Year: 2001
Location: West Chester, Pa.
Posts: 1,370
Gdeaver has a reputation beyond reputeGdeaver has a reputation beyond reputeGdeaver has a reputation beyond reputeGdeaver has a reputation beyond reputeGdeaver has a reputation beyond reputeGdeaver has a reputation beyond reputeGdeaver has a reputation beyond reputeGdeaver has a reputation beyond reputeGdeaver has a reputation beyond reputeGdeaver has a reputation beyond reputeGdeaver has a reputation beyond repute
Re: Sensors

Magnetometers work on robots however that calculated heading most likely will have very little relation to the actual heading of the robot. The hard iron effects can be compensated for. It's the motors that are the big problem. We haven't given up on them yet. Depending on the robot and game a magnetometer may be able to work. Our robot this year has way to many motors all over and there is no place to mount it to get it away from those fields. Our robot last year may be a better candidate. These are the issues we will look at this fall.
Closed Thread


Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 19:58.

The Chief Delphi Forums are sponsored by Innovation First International, Inc.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi