Go to Post the golden rule of robotics for the 21st century: Do unto robots as you would have them do unto you - KenWittlief [more]
Home
Go Back   Chief Delphi > ChiefDelphi.com Website > Extra Discussion
CD-Media   CD-Spy  
portal register members calendar search Today's Posts Mark Forums Read FAQ rules

 
 
 
Thread Tools Rate Thread Display Modes
Prev Previous Post   Next Post Next
  #31   Spotlight this post!  
Unread 20-05-2010, 00:59
EricH's Avatar
EricH EricH is offline
New year, new team
FRC #1197 (Torbots)
Team Role: Engineer
 
Join Date: Jan 2005
Rookie Year: 2003
Location: SoCal
Posts: 19,726
EricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond reputeEricH has a reputation beyond repute
Re: pic: A mechanum wheel that shouldn't bump around at all.

Quote:
Originally Posted by LLogan View Post
I do not think so. The resultant of the vectors is in the direction that they roll. There is no way that the magnitude of the vectors would be the forward/reverse vector because then the vectors that composed it would have to be at 45 degrees which would mean strafing motion would be impossible.

This is what the vectors of a mecanum wheel look like.

http://lib.store.yahoo.net/lib/yhst-...lSpecSheet.pdf
Actually, there is a significant observable slowdown when side-to-side is run as compared to front and back. Part of this is due to friction and other inefficiencies (remember, two of the 4 wheels are running backwards); part of it is due to the vectors. I'm not exactly quite sure how that happens off the top of my head; I think Alan Anderson posted an explanation a while back.

Ether, I posted the part I think led Justin "astray"; namely the logical conclusion that if X< than Y, Z is more effective one way and X > Y, Z is more effective another way, therefore if X=Y, Z is optimized for both directions, and that he simply misstated what he meant. It's up to him to correct me if I'm wrong on that. (Also note that I'm in college, and I don't know/don't remember how to do a matrix transformation. I wouldn't be surprised if that reference confused a number of people. Some explanation may be in order, either in here or in another thread, as to a) what they are, b) how to do them, and c) why they apply here.)
__________________
Past teams:
2003-2007: FRC0330 BeachBots
2008: FRC1135 Shmoebotics
2012: FRC4046 Schroedinger's Dragons

"Rockets are tricky..."--Elon Musk

Reply With Quote
 


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

Similar Threads
Thread Thread Starter Forum Replies Last Post
pic: Alternate view of Mechanum wheel, with blue rollers added. Hawiian Cadder Extra Discussion 5 15-05-2010 02:23
Mechanum Wheel Rollers Stuck ienjoymycereal Technical Discussion 5 31-01-2010 22:38
pic: 342 8-wheel articulation on bump hipsterjr Extra Discussion 5 31-01-2010 11:26
pic: 662 gets a tube wrapped around the wheel gburlison Extra Discussion 10 02-04-2007 17:39
pic: SpamThingAcon Mechanum wheel system Tytus Gerrish Extra Discussion 18 12-05-2005 04:40


All times are GMT -5. The time now is 16:10.

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