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I have looked around the internet at information sites, and I understand that a hybrid control system can be thought of as a series of "layers", meeting at an interface. Such a system combines continuous control (for example, a series of repeated motor rotations) and discrete events (for example, a human turning a knob and gettin the aforementioned motor to rotate to a certain position). Is this all it means? I am getting confused by wording such as the following:
"In the bottom layer the plant model is usually described by means of differential and/or difference equations. This layer contains the actual plant and any conventional controllers working at the same level of abstraction. In the top layer the plant description is more abstract. Typical choices of description language at this level are finite state machines, fuzzy logic, Petri nets, etc. Typically the controllers designed at this level are discrete event supervisory controllers. The two levels communicate by means of an interface that plays the role of a translator between signals and symbols."
I'm not sure how this theory can be translated into the ladder logic of a PLC.
Thanks for any help,
Lee Rehorn
[email protected]
"In the bottom layer the plant model is usually described by means of differential and/or difference equations. This layer contains the actual plant and any conventional controllers working at the same level of abstraction. In the top layer the plant description is more abstract. Typical choices of description language at this level are finite state machines, fuzzy logic, Petri nets, etc. Typically the controllers designed at this level are discrete event supervisory controllers. The two levels communicate by means of an interface that plays the role of a translator between signals and symbols."
I'm not sure how this theory can be translated into the ladder logic of a PLC.
Thanks for any help,
Lee Rehorn
[email protected]