View Single Post
  #12   Spotlight this post!  
Unread 19-10-2016, 19:19
thatprogrammer's Avatar
thatprogrammer thatprogrammer is offline
Registered User
AKA: Ahad Bawany
no team (None)
Team Role: Programmer
 
Join Date: Apr 2014
Rookie Year: 2014
Location: Florida
Posts: 609
thatprogrammer has a reputation beyond reputethatprogrammer has a reputation beyond reputethatprogrammer has a reputation beyond reputethatprogrammer has a reputation beyond reputethatprogrammer has a reputation beyond reputethatprogrammer has a reputation beyond reputethatprogrammer has a reputation beyond reputethatprogrammer has a reputation beyond reputethatprogrammer has a reputation beyond reputethatprogrammer has a reputation beyond reputethatprogrammer has a reputation beyond repute
Re: Tuning PID Constants Over a Range

Quote:
Originally Posted by wesleyac View Post
(Although there are still some considerations to be taken with the difference between going up and down).
Am I correct in my assumption that, given that the equation of the arm's torque (thanks to Austin Schuh for providing this equation!) is: torque = J * d^2 (theta) /dt^2 + F_gravity * r * cos(theta), that
Quote:
F_gravity * r * cos(theta)
can be subtracted when going down to account for that fact that your motors are not fighting the force of gravity being applied on the arm? In other words, when going up, you need to add
Quote:
F_gravity * r * cos(theta)
to account for gravity pushing down on your arm, but you can rely on this force to assist in pushing your arm down when your motors are working to lower the arm?
__________________
Takin' a break.
Reply With Quote