A fuzzy knowledge-based system for railway traffic control

Modern train traffic systems have to fulfill high requirements on service reliability and availability. This becomes especially important with competitive transport markets. Train operators can only meet these requirements by quickly developing an efficient action in case of traffic disturbances. This paper describes a dispatching support system for use in railway operation control systems. It also contains expert knowledge in fuzzy rules of the "IF-THEN" type. Various methods have been proposed for the representation of this kind of knowledge and for reasoning on this base. Expert systems can gain significant success by incorporating fuzzy knowledge and a graphical means of description. The paper describes a Fuzzy Petri Net notion that combines the graphical power of Petri Nets and the capabilities of Fuzzy Sets to model rule-based expert knowledge in a decision support system. Using this approach, a knowledge base is easy to design, analyze, test, enhance, and maintain. An assistant system for train traffic control is presented, and the advantages of this Fuzzy Petri Net notion are shown in the context of application in train traffic control decision support. (C) 2001 Elsevier Science Ltd. All rights reserved.