Fuzzy Logic Poll

Looking for opinions on fuzzy logic.

Have you used it? Success of failure?
Would you use it if you had the chance?

Doug

Is your definition of fuzzy logic where something is at the in between point ie its not 0 but its not 1, where you are predicting that something is about to change?

I am using the standard definition.
i.e, fuzzify, run it through rules, then defuzzify.
Fuzzy logic does deal in analogue values, and during the fuzzification process these values are assigned values between zero and one inclusive.

We are probably talking about the same thing.

Doug

In that case, yes, we use fuzzy logic in our expert control systems for advanced control. I am still learning about that side of things.

That's interesting, are you using PC based or PLC based fuzzy control?

We are using a DCS based system.

I believe we also have a deal with a Canadian compmay to supply an expert system that will be PC based and use OPC to comm to the DCS.
This the website http://www.minnovex.com/indexIE_html.html

I listened to a tele conference with these people a while back and believe this work is continuing.

At my plant instead of looking at a huge chunk of capital for equipment every year to increase production, the company is spending on improving what we have already have through systems and procedures. Sounds simple right?

Big money can be made from simple changes. By using some fuzzy logic on our DCS in one area and fixing up the code, two people working for three months labour cost = $20000 has given us an extra $10 million in extra metal.

I have seen it used in a PLC for stopping crane swing. Have not used it myself.

The basis of the system was an Omron PLC with a variable resistor into an analogue card. The Fuzzy unit did it's calculations and drove the crane quickly one way and then the other to stop the swing. There was a container hanging off the crane.

Hi Bob,

I have seen the crane example used many times as an example of where fuzzy logic could be used, but I didn't know if anyone had actually implemented it.
I've also seen the Omron fuzzy logic card around for quite a few years, and since you can still get it, it must have a market. I have just never seen it being used anywhere.

Hi Doug

I have only seen it the once.

Omron also have a PC fuzzy card and you can also purchase fuzzy chips and software from them.

I think Omron Temp controlerers E5CN work with fuzzy control.

They much better then the others with just PID.