Identification of Discrete Event Systems - Implementation Issues and Model Completeness

This paper presents some practical issues for the identification of discrete event systems (DES). The considered class of systems consists of a plant and a controller running is a closed-loop. Special emphasis is given to a data collection procedure using industrial controllers and its impact on the external DES-behavior of the considered systems. For models identified on the basis of observed external DES behavior using the algorithm from (Klein, 2005) it is shown that under some conditions, the identified model language simulates the complete original system language even if only a subset of this language is available for identification. This model characteristic is crucial for many model-based techniques like diagnosis or verification. Analyzing the observed data of a laboratory facility it is shown how it can be decided if the conditions for a complete model hold for an existing application.