The presence of colored tokens and time opens the possibility to combine high level Petri nets for describing operating procedures and constraint type qualitative models describing the model of the system over a wide operating range. Places can be associated to state variables and the color of the tokens can be related to the qualitative value of the variable. Arc expressions correspond to qualitative model equations. A suitably modified version of the order of magnitude qualitative value representation form is used together with a scaling of each variable to have the same uniform qualitative range. Operations are performed on the interval arithmetic basis and only the result is transformed back to the uniform order of magnitude quantity space. This computation method ensures advantageous algebraic properties. Based on the above idea a novel verification method is proposed in this paper for testing operating procedures against a qualitative model of the system using a high level or colored Petri net representation of the procedure and the model together.
ASJC Scopus subject areas
- Chemical Engineering(all)
- Control and Systems Engineering