Go to Post *referring to Team Titanium's 2012 robot* If only it could play guitar hero at the same time. sigh. - rsisk [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

 
Reply
Thread Tools Rate Thread Display Modes
  #16   Spotlight this post!  
Unread 09-04-2016, 20:36
Agent ZeusChops
 
Posts: n/a
Re: PIDController + Latency - related issues

Pault;
That certainly makes liable sense then. I think Thad did have a solution if the case is such that they tuned the PIDController incorrectly and they don't want to spend a lot of time accounting for the differences. Thanks!
Reply With Quote
  #17   Spotlight this post!  
Unread 09-04-2016, 20:42
ozrien's Avatar
ozrien ozrien is offline
Omar Zrien
AKA: Omar
no team
Team Role: Mentor
 
Join Date: Sep 2006
Rookie Year: 2003
Location: Sterling Heights, MI
Posts: 549
ozrien has a reputation beyond reputeozrien has a reputation beyond reputeozrien has a reputation beyond reputeozrien has a reputation beyond reputeozrien has a reputation beyond reputeozrien has a reputation beyond reputeozrien has a reputation beyond reputeozrien has a reputation beyond reputeozrien has a reputation beyond reputeozrien has a reputation beyond reputeozrien has a reputation beyond repute
Re: PIDController + Latency - related issues

Quote:
Originally Posted by Pault View Post
I'm not sure what options are available in LABVIEW, but the simplest way to do this in Java, C++, and onboard PID with a Talon SRX is to just add a feedforward term.

To add feedforward (kF): remove all other constants, set the setpoint to a specific speed (I've heard 3/4 of max speed is usually pretty good). Then increase the kF until the actual speed matches the setpoint. From there, you can start to play with small values of P and I to get your controller more accurate.
This is better explained in section 12.4. Velocity Closed-Loop Walkthrough – Java, Talon SRX Software Reference Manual.

Maybe OP can start with just describing the problem symptom. An oscillating velocity-closed-loop-output when the target is fixed is a common problem, usually solved with proper gain tuning. Adding an F-term will help, allowing you to have a sharper P-gain with less overshoot.
Reply With Quote
  #18   Spotlight this post!  
Unread 10-04-2016, 01:55
Agent ZeusChops
 
Posts: n/a
Re: PIDController + Latency - related issues

@Ozrien, one of the students at the school would like to see me show up during this week so I might try to see if I can grab a few videos of the shooter specifically. Preferably when the shooter under-shoots, but I'm unaware of the entire situation. I'm aware that there has been shooter-related issues, I'm aware that we never tuned for an F-term, I'm also aware that the P term shoots up our overshoot to setpoint + offset where the offset is the height of the oscillation within the 5-10 seconds where the shooter is active. If I can, I may also try to record the data output from our encoder on the output shaft no real big deal if I cannot get all of the data that should be needed..
Reply With Quote
Reply


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 02:33.

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