Advanced algorithms (PID and Heating Prediction) computation

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Brieuc_Netatmo
Posts: 3044
Joined: 02 Jan 2014, 11:20

Advanced algorithms (PID and Heating Prediction) computation

Post by Brieuc_Netatmo » 28 Oct 2015, 16:21

Hello,

The computation of the advanced heating algorithms requires a learning period, which can range from 3 days to 3 weeks, depending on weather conditions and heating use.
Indeed, the Thermostat needs to know the maximum power of the heating (for example, how long does it take to increase the room temperature by 1°C), as well as the efficiency of the insulation of the dwelling (in how much time is lost 1°C after stopping the heating production).
To do this, the Thermostat must therefore order heating for sufficiently long periods, several times, then observe sufficiently long cooling periods.
It is for this reason that the computation can only be done when the heating is actively used (winter), and if there is a sufficiently significant temperature difference between the Comfort and Eco/Night setpoints. For example, if the Comfort mode setpoint is at 19°C and the Night mode is at 18.5°C, the Thermostat will have difficulty determining with precision the maximum heating power and the quality of the insulation of the home.
As the "advanced heating algorithm" and "heating prediction" functions are independent, one of the algorithms may be ready before the other.
Finally, the PID may not necessarily be useful on high inertia systems, so it is not always offered in cases where the standard hysteresis algorithm already gives excellent results.

Once one of the advanced algorithms is ready to be activated, a popup appears when launching the Energy application to invite you to activate it. Before this, it is not possible to activate the PID, nor the Heating Prediction which uses the data of the Station.
Whether the advanced algorithms are enabled or not, the characteristics of the dwelling are analyzed every 2 weeks, based on the measurements of the days before the last computation, and the parameters of the algorithms are automatically adjusted accordingly if necessary.
If following a major modification of the installation (change of boiler or insulation), the behavior of the Thermostat is no longer optimal, it is possible to switch back to hysteresis mode, while the PID and Prediction are readjusted (for 2 weeks max, consequently).

NB: the PID is automatically deactivated for all setpoint temperatures less than or equal to 14°C. For these setpoint values, the maximum Anticipation duration is also modified: it is 3h maximum for setpoints above 14°C, and 8h maximum for setpoints less than or equal to 14°C.

More information here: https://helpcenter.netatmo.com/en-us/sm ... orithm-pid
Brieuc - Netatmo Team

MarkoR
Posts: 2
Joined: 25 Oct 2015, 09:09

Re: Advanced algorithms (PID and Prediction) computation

Post by MarkoR » 30 Nov 2015, 10:17

Hello,

I have installed the thermostat since October 13 st and till now I do not have calculated PID algorithm.

Could You be so kind and check this via s/n j07cfb2

Thak You a lot.

Update: I do not know is it that because this post, but today my PID is ready. Now I will see all benefits of it :-)
Last edited by MarkoR on 30 Nov 2015, 19:00, edited 1 time in total.

JanMetDePet
Posts: 94
Joined: 03 Oct 2014, 17:18

Re: Advanced algorithms (PID and Prediction) computation

Post by JanMetDePet » 30 Nov 2015, 18:24

It seems that PID does not always work.
NETATMO was working omn my themostat, but I did get keeping an marvelous overshoot for about 2 degrees (and that is MUCH for a heating device.
I turned down the max temp the boiler can use and it solved that problem.
I have to keep looking at the temperatures, in order to turn up the max temp in my boiler.
It works, but it is not my first choice.
Waiting for NETATMO to produce a thermostat with "Open Therm" or will look around for another one.

TypeC
Posts: 289
Joined: 30 Dec 2014, 21:35

Re: Advanced algorithms (PID and Prediction) computation

Post by TypeC » 30 Nov 2015, 21:26

JanMetDePet wrote:I have to keep looking at the temperatures, in order to turn up the max temp in my boiler.
It works, but it is not my first choice.
I'm not saying this is the problem (and apologies if you're aware of this already), but the PID algorithm will never get tuned correctly if you keep changing the boiler temperature. You're introducing another (more or less random) variable that the tuning system will be very unlikely to be able to deal with.

Ceppo
Posts: 1
Joined: 01 Dec 2015, 12:37

Re: Advanced algorithms (PID and Prediction) computation

Post by Ceppo » 01 Dec 2015, 12:48

Hi,
limiting in 3 hours max the anticipation in a non-sense. For a floor heating system it could take up to 5-6 hours to heat up the temperature of 1 degree.

Since last firmware my heating system was working fine. Now it's alwasy colder than the setpoint because it has not enough time to heat-up.
For instance: I've set the 19.5° @16.30, the system start @13.30 (due to the antipation limit) and the actual temperature @16.30 is around 18.8°C

What is the behaviour of this choice? I meand, if the algorithm is working properly, it does not need any limitation, it calculates itself the correct time.

Could you please remove this limit, because with this my "smart" thermostat is useless.

Thank you in advance.
Ciao

HyperTeHK
Posts: 4
Joined: 06 Dec 2015, 21:46

Re: Advanced algorithms (PID and Prediction) computation

Post by HyperTeHK » 06 Dec 2015, 21:52

Ceppo wrote:Hi,
limiting in 3 hours max the anticipation in a non-sense. For a floor heating system it could take up to 5-6 hours to heat up the temperature of 1 degree.

Since last firmware my heating system was working fine. Now it's alwasy colder than the setpoint because it has not enough time to heat-up.
For instance: I've set the 19.5° @16.30, the system start @13.30 (due to the antipation limit) and the actual temperature @16.30 is around 18.8°C

What is the behaviour of this choice? I meand, if the algorithm is working properly, it does not need any limitation, it calculates itself the correct time.

Could you please remove this limit, because with this my "smart" thermostat is useless.

Thank you in advance.
Ciao
I would like to second this, my floor heating is set tot a minimum of 15,5 degrees because of long vacancy. This results in heatup times of about 5/6 hours when it is very cold.
Why the 3 hour limit? Netatmo gets the prediction right.

HyperTeHK
Posts: 4
Joined: 06 Dec 2015, 21:46

Re: Advanced algorithms (PID and Prediction) computation

Post by HyperTeHK » 07 Dec 2015, 15:27

Just checked my thermostat, it now always starts 3 hours in advance.
Has something broke in the firmware? Because today the room temperature is 17,8 and with a target of 18.5 it should have started at about 16:30 not 14:45.

renton82
Posts: 17
Joined: 08 Oct 2015, 15:11

Re: Advanced algorithms (PID and Prediction) computation

Post by renton82 » 10 Dec 2015, 12:31

I have the same problem! Even if the temperature is off about 1C, it starts about 2 hours before! Now i have switched to hysteresis algorithm...

JanMetDePet
Posts: 94
Joined: 03 Oct 2014, 17:18

Re: Advanced algorithms (PID and Prediction) computation

Post by JanMetDePet » 11 Dec 2015, 17:06

TypeC wrote:
JanMetDePet wrote:I have to keep looking at the temperatures, in order to turn up the max temp in my boiler.
It works, but it is not my first choice.
I'm not saying this is the problem (and apologies if you're aware of this already), but the PID algorithm will never get tuned correctly if you keep changing the boiler temperature. You're introducing another (more or less random) variable that the tuning system will be very unlikely to be able to deal with.

You are completly right!
But I HAVE to, because my boiler seems oversized. I had the temp set to max and lowered it in advice from Netatmo.
At this moment I would turn up the temp, but, indeed, I will wait for PID upgrade.

JanMetDePet
Posts: 94
Joined: 03 Oct 2014, 17:18

Re: Advanced algorithms (PID and Prediction) computation

Post by JanMetDePet » 14 Dec 2015, 17:14

Still waiting ....... The desired temp is reached after an hour (AN HOUR).

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