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Unread 06-02-2017, 21:00
rwood359 rwood359 is offline
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Re: Setting PID constants in code for TalonSRX Velocity Control

This is our first time use of the SRX. We are programming in LabView and using the velocity example program..
We have followed the example for Java velocity closed-loop with interpretations for what LV wants.
I am confused about F-gain. We go through the process. Our motor is running at about 6000 RPM maximum. We get a velocity of 39136 from self-test. Using the formulas we compute F-gain as .026139. If we put that value in the F-gain field in the example, the motor runs to full speed when we set the requested output to -25600 (-3750RPM). Both SRXs are showing Green LEDs.

We have tried bringing down F-gain then setting PID values that get us close to what we want. But with our tuning, the SRX doesn't really regulate. When we start other motors, the speed drops 250 RPM, when we put in a fresh battery, the speed goes up 400 RPM.

I think that we are doing something fundamental wrong. Does F-gain need to change based on the speed we are running.

We are using two motors with one in slave mode. Occasionally the SRXs get out of sync after we download and will buck (one showing RED the other showing GREEN) each other.
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