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Unread 14-03-2016, 16:37
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FRC #0449 (The Blair Robot Project)
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Re: Velocity PID control and setpoint ramping

Quote:
Originally Posted by Pault View Post
If the problem is just when the robot stops, I would actually recommend that you use a smaller proportional value whenever the commanded speed is close to zero. This will make the drivetrain drift more if your drivers want it to. It should also stop ruining your gears; they are probably being worn down by constantly oscillating back and forth when trying to stop, but when PIDing to a non-zero value they shouldn't see any abnormal loads.
Is there any convenient way to do this using the standard WPILib PIDSubsystem object?

Quote:
Originally Posted by Hitchhiker 42 View Post
I am pretty sure that there is a velocity ramp function for Talon SRX, where you can make a max ramp steepness, so that there is less jerkiness.
We're doing our PID on the RoboRio, not on the motor controllers. Since our PID output is integrated we can implement a voltage ramp rate using the default setOutputRange() function, but I've heard that input ramping is a better way of handling this than output ramping.
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Member, FRC Team 449: 2007-2010
Drive Mechanics Lead, FRC Team 449: 2009-2010
Alumnus/Technical Mentor, FRC Team 449: 2010-Present
Lead Technical Mentor, FRC Team 4464: 2012-2015
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