Talk:Model predictive control

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The article is at least misleading if not completely wrong. And furthermore is hardly understandable. Rewrite from someone with a clue about MPC needed.

Is this version any better ? Encyclops 00:11, 31 July 2006 (UTC)

Misleading statements

I think the statement:

"Despite the fact that most real processes are approximately linear within only a limitted operating window..."

is very misleading. Many, many real processes of practical importance, and those tackled using MPC are highly nonlinear (e.g. water control systems).

In fact, all processes are nonlinear. Another point is that the cost function is not explictly defined for a mpc. it depends on purpose and economical reasons. "The MPC then sends this set of independent variable moves to the corresponding regulatory controller setpoints to be implemented in the process." As far as I know only the first control move is applied to the process not the set. "linear MPC approaches are used in the majority of applications with the feedback mechanism of the MPC compensating for prediction errors due to structural mismatch between the model and the plant" Not only for structural mismatch but also for exogenous disturbances. —Preceding unsigned comment added by 87.78.92.134 (talk • contribs)

I agree, this needs work. There are two main reasons to use model-based predictive control. One is that there are multiple, interacting control inputs. Feedback alone won't handle that; some form of model that relates the inputs to the outputs is needed. That's what the article currently covers.

The second use of model-based predictive control is when the system has significant lag. If the delays in the system between a control change and and an output change are large, and there's some source of disturbance that affects the controlled value, feedback control can't keep up. The classic situation is heating for large buildings, where there's a long delay between requesting heat for an inside space and getting heat from a faraway heating plant. An outside temperature sensor is often used as a disturbance input, so that a drop in outside temperature cranks up the heating system in anticipation of heat demand as the building structure cools. Historically, such things are manually tuned, but there's a trend towards making the whole system adaptive. Here's a limited reference from Google's book scanning: [1].

This stuff can be explained better. It's really not that complicated. --John Nagle (talk) 04:10, 10 March 2008 (UTC)

Ok, I took a stab at changing the "Overview" section. I hope this actually helps! Rbh1976 (talk) 16:56, 2 May 2011 (UTC)

The statement regarding use in power systems is also misleading. It has been proposed (as citation suggests), but unless someone can cite a specific example, I suggest not stating that it is used in power systems. — Preceding unsigned comment added by 142.104.85.182 (talk) 18:44, 11 May 2015 (UTC)

External Links

Are the external links in the "Commercially available MPC software" section okay? My understanding is that in the actual text no external links should appear because otherwise every firm name or whatsoever mentioned in an article could/should also be externally linked. So if there is nobody against it, I will completely delete them with the next days in case no one else did so.(I wouldn't ask but one of them has been there a good month) TFTD (talk) 12:53, 13 October 2009 (UTC)

WP:EL I guess this justifies a deletion TFTD (talk) 13:42, 13 October 2009 (UTC)

Section Commercially available MPC software

What is the purpose of this section? It seems to me that it is mostly used to advertise products while using external links. I would suggest to outsource this part in a "List Type Article" (if at all). For now I just took care of the WP:EL (see above) TFTD (talk) 12:06, 11 October 2010 (UTC)

I agree with you. This section seems to be used for advertising, and is of questionable value. Perhaps it needs to be removed. Encyclops (talk) 14:41, 11 October 2010 (UTC)

It does look a bit like that, I think list is probably only justifiable here if said software is in itself notable in the field and listing would useful to a reader.Firebladed (talk) 15:11, 11 October 2010 (UTC)

So if nobody thinks it is worth saving I think one can delete it in a couple days. The way it is now, from my point of view, is not useful (as one has to google for all the not saying anything acronyms) and as said above only advertisement to me. And I guess a beginner of the topic is not really interested in software solutions and somebody actually working with it should be able to use google or has a given software anyway. TFTD (talk) 07:35, 13 October 2010 (UTC)

Well, I changed it along the lines suggested. Encyclops (talk) 17:02, 19 October 2010 (UTC)

Fixed vs Receding Time Horizon?

The terminology in "LQR optimizes in a fixed time window (horizon) whereas MPC optimizes in a receding time window" is confusing. If one has a fixed time window, say, 7 days, and one advances a day in time, the window slides one day so the new time window "recedes" one day. Likewise, if a time window "recedes" as time moves on, it implies a fixed time window or at least a time window that does not shrink as rapidly as time advances. Could someone please clarify this terminology in the comparison of LQR vs MPC? Jim Bowery (talk) 15:17, 30 March 2019 (UTC)

Code example doesn't really work as written and may be better as a link

The long block of code is from the main function in https://github.com/AtsushiSakai/PyAdvancedControl/blob/master/mpc_path_tracking/main.py, but the code pasted into the page doesn't work without the rest of the python file and library dependencies. So copying the code from the page and trying to run it doesn't work - the whole package needs to be installed. For this reason I'd recommend deleting the verbatim code example and just keep the link to the package. Dominic Widdows (talk) 19:22, 26 September 2022 (UTC)

I agree and support this decision. IMO, this subsection should be deleted and the link to this repository could go to the External links. Saung Tadashi (talk) 20:54, 26 September 2022 (UTC)