Go to Post Quitting when faced with adversity is not the answer. We have to figure out a solution within the constrainsts applied. - Rob [more]
Home
Go Back   Chief Delphi > Technical > Technical 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
  #41   Spotlight this post!  
Unread 30-09-2003, 10:20
Frank(Aflak)'s Avatar
Frank(Aflak) Frank(Aflak) is offline
Registered User
#1067 (SLUH)
 
Join Date: Dec 2002
Location: Saint Louis
Posts: 375
Frank(Aflak) is on a distinguished road
By 'real' i meant professionally made with either low friction non-bearing rollers or bearings for the rollers. Also, professionally produced omniwheels are more likely to withstand a beating.

And, i believe it is possible to get 100% motor torque using four wheels.

look at it this way,

._
{_}
.
where the '{' and '_' are the wheels.

say you power the {} wheels in the same direction. you get full power/torque out of them.

Say you power the '_' wheels in the same dircetion, same deal.

Now lets say we geared the motors so that when only one set of wheels are powered, you get 6 feet/second and whatever push that translates to. If you power BOTH sets you get the robot traveling in a diagonal, at the new speed 6rt(2) feet per second, and a new power that is sgrt(2) times the power of an individual set of wheels. so, you get 2x the power of one set of wheels, and one set of wheels gives you the same power from he motors that a tank drive would, so with twices the motors ou get twice the power of a four-motor tank drive, which gives you 100% power except for gearing and wheel inefficiencies. I don't see where your 70% is coming from . . perhaps I can get a link to an explanation . . . ?

at the 45' diagonals you get 100% power out of the motors. The only way it isn't as powerful as a tankdrive at same geared to he same speed is that you are loosing power to make the rollers turn, which is a near-negligable loss.

I don't understand how it could be different . . I accept that you only get full power at the 45' diagonals, but that is still another axis of freedom on which full power is available over a tank-drive.

edit: your idea about using a compass/angular acceleration sensor: We have been planning that since last season. It will be in place using one or two solid-state gyros. Error will add up, but we may build a control that allows for the secondary driver to manually adjust the robot's percieved heading so the error can be corrected as the match progresses.

edit: I looked over your post a second time, and it is true that at the diagonals you get sgrt(2) times the power of each individual set of wheels, but I think you failed to consider that you ALSO get sqrt(2) times the speed, so twice the power. You gotta look at both. And you need a driver who is aware of all of this.

Last edited by Frank(Aflak) : 30-09-2003 at 10:25.
 


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
Any Tips on the Design of Drives Argoth 3D Animation and Competition 0 03-11-2003 22:00
What's the best combination for bot types this year? authgeek1218 Rules/Strategy 5 09-01-2003 00:14
Button types Scottie2Hottie General Forum 7 27-03-2002 00:13
External Hard Drives... David Kelly Chit-Chat 8 01-12-2001 21:28
Music types Carolyn Duncan Chit-Chat 42 03-08-2001 23:06


All times are GMT -5. The time now is 06:13.

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