Stephen Mitschke
August 12th, 2003, 12:10 PM
Hi All,On the control strategy in the field regulators to Fieldbus did wanttoknow if this already includes the strategy Fuzzy, Control AdaptiveandPredictive (SCAP) and nets neuronales and are they already sold inthemarket???? greetings, Freddy- - - - To my knowledge no manufacturer at present offers more than PID control. Itwill however be possible to do what you ask in the future when manufacturersadd the algorithm(s) you want into another block, perhaps the Arithmeticblock.The other constraint is that the fancier things get, the more power it takesto run the chip. As you know with chips improving all the time this couldstop being an issue in the future but I think it may still be a secondfactor today.Is anyone out there doing or planning:Fuzzy LogicAdaptive Predictive ControlNeural NetworksIan Verhappen- - - You may not like the answer, but I believe that DeltaV has these algorithmsin it's library. They are not intended to operate in field devices,however. I believe that autotuning and fuzzy logic will eventually becomeavailable as downloadable algorithms from the vendors which currentlysupply them on their DCS. I do believe that neural nets and modelpredictive controls are probably in the category of algorithms best reservedfor a controller.Dick Caro- - - - National Instruments offers a product FP-3000, Fieldbus I/O controller<http://sine.ni.com/apps/we/nioc.vp?lang=US&pc=mn&cid=1845>, that supports acustom function block called "Expression" that allows the user to writetheirown control code (subset of C code) within the block. The Expression blockhasmultiple analog and digital inputs/outputs which can be used as variableswithinthe control code. Various I/O modules (analog and discrete) can becontrolledby the FP-3000.Chris LeBlancNational Instruments- - - - There is an IEC effort to standardize blocks like the one mentioned byChris. The flexible block should use standard IEC 1131 language. Marcos- - - - Delta V has Autotuning, Fuzzy and neural.We will be introducing the first two in our field devices as well.As these algorithms are released, they can be downloadable to the fielddevices via Fieldbus.Regards,Marcos- - - - -