Need help with PID Autotuning

Discussion in 'E3D-v6 and Lite6' started by JvdP, Aug 3, 2014.

  1. JvdP

    JvdP Well-Known Member

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    I got my E3Dv6 in the mail on friday and was really impressed with the size and the quality of this hot-end. Assembly was quick and relatively easy.

    Then the software part came, this was a little less easy and I need some help.

    I have a Printrboard with a special firmware for my QU-BD Two-Up called "Up-Marlin". As you can guess from the name it's based on Marlin, so we can use all PID autotune features like on Marlin.

    Unfortunately, I can't seem to get it autotuned correctly. It's not that the autotune itself doesn't work, but rather the results that I get after tuning. If you see in the image below, you will notice quite some overshoot (10) when I target 200 degrees C.

    [​IMG]

    I use Repetier Host v1.00 on Windows 7 and after doing a PID Autotune with: M303 S200 C10 I got the following numbers:
    Code:
    Kp: 17.97
    Ki: 1.56
    51.81
    I saved theses in my EEPROM through Repetier host and then rebooted and reconnected the Printrboard (just to make sure). I've also tried putting them straight in the firmware and flashing it to the Printrboard,
     
  2. elmoret

    elmoret Administrator

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    Plot above looks fine, autotune focuses on steady state response not transient. If you care about startup overshoot, you'll have to sacrifice SS performance or implement gain scheduling.
     

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