View Single Post
  #13   Spotlight this post!  
Unread 10-02-2005, 00:18
Kevin Watson's Avatar
Kevin Watson Kevin Watson is offline
La Cañada High School
FRC #2429
Team Role: Mentor
 
Join Date: Jan 2002
Rookie Year: 2001
Location: La Cañada, California
Posts: 1,335
Kevin Watson has a reputation beyond reputeKevin Watson has a reputation beyond reputeKevin Watson has a reputation beyond reputeKevin Watson has a reputation beyond reputeKevin Watson has a reputation beyond reputeKevin Watson has a reputation beyond reputeKevin Watson has a reputation beyond reputeKevin Watson has a reputation beyond reputeKevin Watson has a reputation beyond reputeKevin Watson has a reputation beyond reputeKevin Watson has a reputation beyond repute
Re: Problems with PID- PLEASE HELP!!!

Quote:
Originally Posted by thinkpad
I got the mechanical guys to put the encoders on the output chain of the wheel, and the current calculated counts per wheel revolution are 299 counts/ wheel revolution. It does work for driving a fixed length in a straight line right now, but it is at relatively lower speed that we will have on our final robot mobility. Is this counts per revolution OK (hopefully not overkill like before, especially if we want high speeds)?
Should be okay. Make sure that the encoder shaft isn't going to experience any side load from chain slap, etc.


Quote:
Originally Posted by thinkpad
Now I am trying to get the robot to turn (using the gyros), is there a variable where we can calibrate the turning speed as per our gearboxes? We have a tank like mobility system so the turning isn’t very sharp, so when i ask the scripting to turn 90 deg (1500 miliradians), I can see the motors are spinning at different rate, but since it is encountering a lot of friction I was wondering if it is possible to make it turn sharper?
No, there isn't. Try writing a PID control loop that controls angular rate using the gyro.

-Kevin
__________________
Kevin Watson
Engineer at stealth-mode startup
http://kevin.org