Hardware implementation of a fuzzy Petri net based on VLSI digital circuits

Industrial processes can be often modelled using Petri nets. If all the process variables (or events) are assumed to be twovalued signals, then it is possible to obtain a hardware or software control device, which works according to the algorithm described by conventional Petri net. However, the values of real signals are contained in some interval and can be interpreted as events which are not only true or false, but rather true in some degree. Such a natural interpretation concerns sensor outputs, control signals, time expiration, etc. It leds to the idea of the fuzzy Petri net (FPN) as a controller, which one can rather simply obtain, and which would be able to process both analog, and binary signals. The paper presents hardware implementation of such a net based on VLSI digital circuits. A new method of the synchronous and asynchronous hardware implementation of fuzzy Petri net was described. The circuits were tested and implemented as control devices for laboratory plant.