View Single Post
  #15   Spotlight this post!  
Unread 17-04-2003, 23:36
Unsung FIRST Hero
Al Skierkiewicz Al Skierkiewicz is offline
Broadcast Eng/Chief Robot Inspector
AKA: Big Al WFFA 2005
FRC #0111 (WildStang)
Team Role: Engineer
 
Join Date: Jun 2001
Rookie Year: 1996
Location: Wheeling, IL
Posts: 10,770
Al Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond repute
Quote:
Originally posted by Abwehr
Each "tick" of a rotation sensor would correspond with a distance travelled equal to the circumference of the wheel, as I understand it.
The rotation sensor actually is measuring a distance much less than the circumference of the wheel. Our resolution is under two inches per tick and with the tread material we use slippage is kept to a minimum. All in all the accumulated error due to slipping in a 15 second period doesn't amount to very much. If the auto mode was longer than 15 seconds we would need to use something else, perhaps a fifth wheel. A bigger problem is that with a rigid frame and no suspension, all the wheels do not stay on the ground when hitting the ramp at an angle. Our sensors are only on one wheel at the moment and perhaps sensors at every wheel averaged in software would make things more accurate. Of course that would add weight and we are already at 130.
__________________
Good Luck All. Learn something new, everyday!
Al
WB9UVJ
www.wildstang.org
________________________
Storming the Tower since 1996.