Thread: More Wheels?
View Single Post
  #14   Spotlight this post!  
Unread 22-03-2009, 01:46
artdutra04's Avatar
artdutra04 artdutra04 is offline
VEX Robotics Engineer
AKA: Arthur Dutra IV; NERD #18
FRC #0148 (Robowranglers)
Team Role: Engineer
 
Join Date: Mar 2005
Rookie Year: 2002
Location: Greenville, TX
Posts: 3,078
artdutra04 has a reputation beyond reputeartdutra04 has a reputation beyond reputeartdutra04 has a reputation beyond reputeartdutra04 has a reputation beyond reputeartdutra04 has a reputation beyond reputeartdutra04 has a reputation beyond reputeartdutra04 has a reputation beyond reputeartdutra04 has a reputation beyond reputeartdutra04 has a reputation beyond reputeartdutra04 has a reputation beyond reputeartdutra04 has a reputation beyond repute
Re: More Wheels?

Quote:
Originally Posted by keehun View Post
Is it possible (and legal) that you make pneumatics strong enough that you mount a wheel perpendicular to other wheels, then when you want to brake, you gently lift the robot using that wheel, tilting it just ever so slightly, and applying that downward pressure and braking faster?

Imagine sliding your hand over the desk, and the sliding your hand over the desk with a lot of downwards pushing..?
If you think about it, that will only work as long as the robot mass is accelerating upwards.

As soon as the robot stops accelerating upwards (and begins to coast), the force pushing down on the wheels will return to its pre-acceleration value. But a robot cannot possibly keep moving upward forever, or even offset a partial amount of its downward acceleration due to gravity.

Therefore, the robot must begin to slow down its upward velocity, experiencing negative acceleration. During this period, the robot will actually have less normal force pushing down on the wheels, meaning less pushing power.

So yes, you can do this; you'd just get a very limited period of increased traction followed by a limited period of decreased traction.

Think of if like a roller coaster. When you go through a dip, you feel positive gee forces, and when you go over a peak you feel negative forces.
__________________
Art Dutra IV
Robotics Engineer, VEX Robotics, Inc., a subsidiary of Innovation First International (IFI)
Robowranglers Team 148 | GUS Robotics Team 228 (Alumni) | Rho Beta Epsilon (Alumni) | @arthurdutra

世上无难事,只怕有心人.