FUZZY CAUSAL SIMULATION IN PROCESS ENGINEERING

摘要

This paper presents a causal simulation method for incompletely known dynamic systems in process engineering. The causal model of a process is represented as both a causal network of interacting elementary dynamic systems, called qualitative automata, influencing one another, and a set of qualitative constraints linking possibly several of such automata. Associated with each influence is a weight which expresses its sensitivity. A procedure is presented which allows us to generate fuzzy weights from the relative order of magnitude relations between them. Formulae preserving non-linearities and fulfilling some relevant requirements are provided to compute net influences on extensive variables as well as on intensive ones. Finally an algorithm is given for simulating the causal model, and an example application to a fed-batch fermentation process is presented.