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Unread 28-11-2014, 12:31
Happy Birthday! Zaque Zaque is offline
FF: Bobo Brigade
AKA: Zachary H.
FRC #3352 (Flaming Monkeys)
Team Role: Programmer
 
Join Date: Mar 2013
Rookie Year: 2013
Location: Belvidere, Illinois
Posts: 91
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Re: Swerve questions (Languages, CAN)

Quote:
Originally Posted by bharrison6 View Post
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I thought you could use PWM to control a closed loop CAN but it turns out to be just quadrature that is supported. (Which is just 2 PWM signals plus an index signal)

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2. PWM input from an absolute encoder will not work in a closed loop. 3. Analog input for an absolute encoder will not work in a closed loop. So my questions are. 1. Can you use quadrature input which is supported by a closed loop to get position of the pod? (I assume it would required a quick 360 at the beginning of the match to get the index and then just keep up with position from there) 2. If quadrature input to closed loop CAN will not work to control position, then what do swerve teams use? (If it isn't closed loop how do they deal with lag in the system?)
I wanted to mention something here to keep others from getting confused. I think when you say "closed loop" you are referring specifically to using the closed loop control on the speed controllers. However, any system that uses sensor feedback is closed loop, whether the feedback is on the speed controller, the roboRIO, or some other controller. So those sensor outputs are usable for closed loop control, just not on the speed controllers.
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Zaque (Zach) H.
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