Usually users who have big and thick beds have an offset between the bed surface and the thermistor temperature located on the heater, also they usually need to wait some time for the bed surface to reach the thermal equilibrium with the heater. I opened a pull request with a dual loop PID. This n…

I have worked a lot with classical SISO (single input single output i.e. “typical”) controllers both personally and professionally, but I don’t have a very deep understanding of MISO. Somebody who knows MISO well might have a more elegant solution than this, but this block diagram is how I would tac…

I guess you are doing MISO control, if I understood mykepredko’s attachment in the right way. For me is MISO like Berggipfel’s explanation.

I think you need to read the article I linked as well as other ones to put together a MISO implementation properly. In your block diagram, you have a proportional temperature control of the heater with additional input from the surface thermistor. I’m concerned that you have positive feedback from…

I’m not the one trying to implement this, just offering my two cents. But, you got me curious so I did some simulations :slight_smile: Note: these numbers are not to be taken literally. The characteristics of the heater, heat transfer through the bed to the build surface, PID parameters, etc. would…

Interesting thank you - what tool did you use for the simulations? I would be surprised if the systems here were properly modeled in terms of thermal mass and convection cooling but I have two comments from what I see here: In trial 3, that saturation block behaves differently than how I interpre…

This was done in Simulink, but unfortunately that’s not feasible for most people to have access to. OpenModelica is free software that could have done this just as well if people reading are looking for a tool. To your first point, I always find decision blocks in flow charts to be prone to misinte…

Interesting. I also have a similar bed temperature monitoring setup on my Voron2 printer. The bed heating pad has a thermistor on it, and I have added a thermistor to the bottom of the aluminum plate ( voron2-mods/bed.md at master · KevinOConnor/voron2-mods · GitHub ). At least on my printer I am…

Hi Kevin, I’m still new to macros but why do you have two assignment statements for “BED_HEAT” with different values? gcode: {% set BED_TEMP = 105 %} {% set EXTRUDER_TEMP = 245 %} {% set BED_HEAT = 115 %} Wouldn’t the second assignment overwrite the first?

I think you misread BED_TEMP vs BED_HEAT. -Kevin

Dual Loop PID, a accurate bed surface temperature

Features

rmda May 27, 2023, 7:48pm 24

you can use my fork, I already implemented it

Feature idea: bed temperature loss compensation

Topic		Replies	Views
Thick bed temperature controll General Discussion	50	1067	October 22, 2025
Feature idea: bed temperature loss compensation Features	24	2434	December 5, 2023
Experimental PID improvement changes Developers	72	8590	January 10, 2023
Direct Acting Bed PID General Discussion	39	1030	April 18, 2024
Remove the 300ms heater control delay? Developers	12	756	October 6, 2024

Dual Loop PID, a accurate bed surface temperature

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