Citation

Kezić D, Antonić R, Račić N. Promet 2006; 18(3): 143-150.

Copyright

(Copyright © 2006, Faculty of Traffic and Transport Sciences, University of Zagreb)

DOI

10.7307/ptt.v18i3.679

PMID

unavailable

Abstract

The article deals with the system of port cranes comprising two independently controlled cranes which are simultaneously engaged in the transhipment of cargo between a vessel and arailway wagon assembly alongside. A crane operator's error can lead to the collision of cranes. Therefore, it is necessary to install the supervisor in an automatic control system with the functions of continuous supervision of the process of crane movement, and blocking of commands that can lead to collision. The article shows the method of crane system modelling as a discrete event system by using PIT and P-timed Petri nets.There is a proposal of a formal mathematic method for calculation of the state supervisor by P-invariant method. The supervisor calculated in this way is maximally permissive supervisor.The efficiency of the supervisor is verified by a computer simulation.

Language: en