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Unread 10-13-2018, 08:29 PM
ozdave ozdave is offline
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Talon SRX position hold PID

Hi all

Are there any general recommendations for settings for the PID parameters when using the Talon controlmode.position mode to hold an elevator our an arm in position?


Regards

David

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Unread 10-13-2018, 09:14 PM
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Re: Talon SRX position hold PID

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Originally Posted by ozdave View Post
Hi all

Are there any general recommendations for settings for the PID parameters when using the Talon controlmode.position mode to hold an elevator our an arm in position?


Regards

David

Sent from my SM-N960U using Tapatalk
Use the arbitrary feedforward to help hold it up by applying a static voltage. For an elevator, that's a constant (it's around 0.15 on ours). For an arm, it'll vary with the angle.
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Unread 10-13-2018, 09:46 PM
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Re: Talon SRX position hold PID

As far as a general recommendation - provide a counter-spring or counterweight so that the required torque to hold a position is minimal. This will significantly reduce the amount of work your motors need to do both to get to a position, and to hold it. IIRC, the programmers didn't even need to change the PIDs from their default values with the arm 3946 did this year for Bayou thanks mostly to some counter-springs.

Note that even for an elevator, the required current is likely to change to hold a position if the load changes (e.g. cube vs no cube). Unless countered, arms will usually require the greatest current to hold a position where the CoG of the arm is at the same level as the pivot, and decrease roughly as the cosine of the angle from the horizontal.
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