View Single Post
  #1   Spotlight this post!  
Unread 03-02-2009, 19:13
ComradeNikolai ComradeNikolai is offline
Registered User
AKA: Nicholas
FRC #2603 (Team Hornet)
Team Role: Mentor
 
Join Date: Feb 2008
Rookie Year: 2008
Location: Medina, Ohio
Posts: 203
ComradeNikolai is a splendid one to beholdComradeNikolai is a splendid one to beholdComradeNikolai is a splendid one to beholdComradeNikolai is a splendid one to beholdComradeNikolai is a splendid one to beholdComradeNikolai is a splendid one to beholdComradeNikolai is a splendid one to behold
Re: Using encoders for traction control help

Quote:
Originally Posted by ellisk View Post
So, if I understand your algorithm correctly, it works like this (for each side):

1. Get the acceleration according to each encoder on the transmission
2. If the acceleration is too high, compute the ratio:

maximum_acceleration / real_acceleration

where maximum_acceleration is determined experimentally. Then, multiply the desired motor value by said ratio.

Is that right? So do you just ignore the velocity according to the encoders on the omni wheels (undriven wheels)? It sounds simple, but it also sounds like it could work (occam's razor ftw).
Yes, except I actually am just using a constant instead of the ratio; I am going to try that ratio idea, though; I rather like it, and it may work a bit more optimally, as well.

I do ignore velocity, and we don't have any omni encoders, and I haven't installed our accelerometer or gyro yet. The one thing I could add would be a comparison to test for real time slipping -- this will only occur if we get in a shoving match, especially against a wall, but in those cases, I trust our drivers to compensate.

Occam's Razor always wins.
__________________
I cut myself shaving with Occam's razor.