Fuzzy logic with ladder diagram

[a13di63]

hello all masters PLC,

I want to ask something about fuzzy logic.

how to apply fuzzy logic into the ladder diagrams?

 

[Peter Nachtwey]

Here we go again

Why?

Trying to implement FL using ladder requires a lot of code compared to a simple PID. Get a micro controller that has a fuzzy logic library.

 

[Binaural]

If you have to use a PLC, but have the option of choosing what language, I would not use ladder for this but something like structured text (http://en.wikipedia.org/wiki/Structured_text). At least your calculations will be halfway readable!

 

[a13di63]

Why?

Trying to implement FL using ladder requires a lot of code compared to a simple PID. Get a micro controller that has a fuzzy logic library.

I just want to try, because I think that fuzzy logic is only part of ANDGate logic. possible between all of the masters PLC anyone ever makes it.

Sorry about my english, very bad.

:site:

 

[ndzied1]

Many years ago, I'm talking like somewhere between 1990 and 1993 was the first time I saw the term Fuzzy Logic. I distinctly remember an article that explained, in pretty good detail, a method of counting chicken eggs coming down a conveyor.

I cannot remember the magazine I saw this in. On many occasions, I have gone on internet searches looking for this article but to no avail.

 

[jvdcande]

Some years ago I had a student who did it for his final study project. It is doable, but it took a lot of work. And I have to say this was a really brilliant student. I'm convinced he did something which is out of reach for about 85% of the average programmers.

Unfortunately, I'm no longer involved in the PLC training and I don't have access any more to this project.

Kind regards,

 

[shooter]

yes it is possible, however with function blocks it will be much easier.
the logic AND is not used it is a fuzzy AND. that is almost same as using MINimum in ladderanalogic.
ANDing with bytes will not work in fuzzy.

 

[a13di63]

@ all

ok. thanks all.:nodi:

I have one more question
today I tried the function of PID (190), I use an analog input as the input word and the analog output as the output word.

I have tried many examples from this forum, but I still do not understand how step by step using the PID (190). I use a Omron plc CS1H CPU64-H. AD041-V1 analog input, analog output DA041.

please help.

 

[widelto]

I know rockwell has a fuzzy version to be used with plcs, it not free nor cheaper either.

 

[tracer]

If you really have to have fuzzy logic, there's a plc made in korea, I beleive the company name is lgis it will run a basic style program simultaneously with a ladder logic program, cubelocs & some other micro controllers will also do this