» Download Article

Authors
Elzbieta Roszkowska

Identifier
10.3182/20060906-3-IT-2910.00062

Index Terms
guidepath-based traffic system,DES-based controller,liveness enforcement

Abstract
The paper presents a DES-based controller for an emerging, important class of industrial and public transport media - guidepath-based, zone-controlled, closed traffic systems. We build upon and extend our earlier results concerning the formal methods of control synthesis. An essential requirement for the traffic flow in these systems is that the vehicles maintain their ability to access every location in the underlying guidepathnetwork, throughout the entire, presumably infinite, length of the system operation. The proposed construction ensures the required qualitative features of the control and gives a formal framework for the development of the computer-aided system that allows an experimental, simulation-based optimization of the parameters that decide about the system efficiency.

References

[1] Bozer, Y. and M. Srinivasan (1991). Tandem configurations
     for AGV systems and the analysis of single
     vehicle loops. IEE Trans. 23, 72-82.
[2] Egbelu, P. J. and J. M. A. Tancho (1986). Potentials for
    bidirectional guidepath for AGV based systems.
    Int. J. Prod. Res. 24, 1075-1099.
[3] Fanti, M. P. (2002). Event-based controller to avoid
    deadlock and collisions in zone-control AGVS.
    Int. J. Prod. Res. 40(6), 1453-1478.
[4] Kreczmer, B. (2006). Transport network modeller and
    simulator. Wroclaw University of Technology,
    Report I-6/06/S-08.
[5] Reveliotis, S. A. (2000). Conflict resolution in AGV
    systems. IIE Transactions 32(7), 647-659.
[6] Roszkowska, E. (2002a). Liveness of states in closed
    AGV systems with dynamic routing. In: Proc.
    MMAR'02. pp. 947-952.
[7] Roszkowska, E. (2002b). Undirected colored Petri net
    for modelling and supervisory control of AGV
    systems. In: Proc. WODES'02. pp. 135-142.
[8] Roszkowska, E. (2004a). Liveness enforcing in closed
    AGV systems with dynamic routing. In: Proc.
    ICRA'2004. pp. 5165-5170.
[9] Roszkowska, E. (2004b). Recognizing and handling
    the livelock problem in AGV systems. In: Proc.
    IEEE Int. Conf. SMC. pp. 1637-1642.
[10] Roszkowska, E. and B. Kreczmer (2006). Control and
     simulation system for guidepath-based transport
     vehicles networks. Wroclaw University of Technology,
      Report I-6/06/P-16.
[11] Wu, N. and M. Zhou (2003). AGV routing for conflict
     resolution in AGV systems. In: Proc. ICRA'2003.
     pp. 1428-1433.