OCCRA
Go to Post I've determined that the only thing rumors are good for is putting your knickers in a twist. - JaneYoung [more]
Home
Go Back   Chief Delphi > Technical > Programming
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
  #1   Spotlight this post!  
Unread 09-13-2017, 07:55 PM
dardeshna's Avatar
dardeshna dardeshna is offline
Team Captain
AKA: Devin Ardeshna
FRC #0008 (Paly Robotics | Team 8)
Team Role: Mechanical
 
Join Date: Dec 2015
Rookie Year: 2015
Location: Palo Alto
Posts: 114
dardeshna is a name known to alldardeshna is a name known to alldardeshna is a name known to alldardeshna is a name known to alldardeshna is a name known to alldardeshna is a name known to all
Tuning a PIDF follower on a robot with high gearing

One of the problems we have been encountering during the off-season is tuning a PIDF follower reliably on our 2017 robot. It is geared with a fairly high theoretical top speed (~17fps), and our autonomous trajectories are generated with a maximum velocity of about 5fps. This means there isn't much torque at the wheels compared to resistive forces.

Without feedback terms, velocity does not track well. Generally a kV and kA value that work at faster speeds (4-6fps) are inadequate for slower speeds (2-3fps). We can add in feedback, but a few things happen:

1) The Kp term does more corrective work than it should be doing
2) Because of the large error, following is inconsistent between different trajectories

How do teams overcome this inconsistency at lower torque and get better tracking with feed-forward terms before moving on to adding feedback terms?
__________________
Devin Ardeshna
Team Captain (Paly Robotics FRC #8)


2017 Ventura Regional Quarterfinalist, Entrepreneurship Award, and Creativity Award, Silicon Valley Regional Finalist, Entrepreneurship Award, and Wildcard, Roebling Division Semifinalist, Chezy Champs Quarterfinalist, Capital City Classic Semifinalist
2016 Central Valley Regional Finalist and Wildcard, Silicon Valley Regional Quarterfinalist, Curie Division, CalGames Quarterfinalist and Entrepreneurship Award, Capital City Classic Quarterfinalist
2015 Central Valley Regional Entrepreneurship Award, Silicon Valley Regional Entrepreneurship Award, Capital City Classic Semifinalist and Judges' Award
Reply With Quote
 


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


All times are GMT -5. The time now is 04:23 PM.

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