Thread: Guidance for PID Tuning (Ziegler–Nichols method leading to EXTREAMLY High P value)
View Single Post
  #3   Spotlight this post!  
Unread 10-03-2016, 23:13
Basel A's Avatar
Basel A Basel A is online now
It's pronounced Basl with a soft s
AKA: @BaselThe2nd
FRC #3322 (Eagle Imperium)
Team Role: College Student
  
Join Date: Mar 2009
Rookie Year: 2009
Location: Ann Arbor, Michigan
Posts: 1,935
Basel A has a reputation beyond reputeBasel A has a reputation beyond reputeBasel A has a reputation beyond reputeBasel A has a reputation beyond reputeBasel A has a reputation beyond reputeBasel A has a reputation beyond reputeBasel A has a reputation beyond reputeBasel A has a reputation beyond reputeBasel A has a reputation beyond reputeBasel A has a reputation beyond reputeBasel A has a reputation beyond repute
Re: Guidance for PID Tuning (Ziegler–Nichols method leading to EXTREAMLY High P value
1. Yes, absolutely tune under load

2. Remember that your constants are ratios of output over input. In the case of the talon SRX, your output is a value from 0 to 1023 (full throttle at 1023). This can result in much higher P constants than you're used to (usually your output is 0 to battery voltage or 0 to 1).

3. Is our load close to the max torque of the motor? If so, your control is probably at its ceiling for most of the time before it reaches the setpoint. In ideal situations, the output is unlimited, so the motor will perform consistently. However, if your output is limited for a significant period, then your results will vary with your battery voltage.

4. I have no guidance on that one.
__________________
Team 2337 | 2009-2012 | Student
Team 3322 | 2014-Present | College Student
“Be excellent in everything you do and the results will just happen.”
-Paul Copioli