Elevator Motion Profiling / PID Ramping

[Tom Bottiglieri]

Originally Posted by Jared

I have two ideas that might help
If you want to stick with plain PID, you could try just increasing the value of kD. If it starts to oscillate a lot, try a low pass filter (moving average over 0.1 seconds or so) on the sensor value. This will help slow the elevator, but it may not be enough.
.

Off topic a bit - I saw your team was using Java this year. Have you run into issues with the timing of the JVM's Timer? We have used this construct successfully over the past two years, but on the roborio the timing is complete garbage. We have ditched using derivatives on any control loops due to massive noise.

My best theory is the squawkVM was ported manually and used VXworks timers under the hood. The standard JRE we use now probably just sleeps or something.