Modelling And Implementation Of AVS/RS Based On Dual Colored Dynamic Timed Petri Nets

The Autonomous Vehicle Storage and Retrieval Systems (AVS/RS) will be the development direction for automated warehouse. It will be an essential component of the Flexible Manufacturing System in future.According to the phyical structure and logical characteristic of the AVS/RS, the paper proposes a new modeling method—the Dual Colored Dynamic Timed Petri Net (DCDT-PN) on the basis of petri nets. Dual colored is proposed not only to predigest the same structure of the model of AVS/RS in the macro perspective, but also describe the dynamic attributes of each place in the micro perspective, which make sure the integrity of the attribute information. in addition, Considering the dynamic characteristics of the system, the dynamic timed is proposed to describe the control process of the active resources in system. The DCDT-PN model of AVS/RS is established via modularize idea base on analyzing the behavior of resources detailedly.On the base of the DCDT-PN model, the paper unifies directed graph, research the cycle (cycle chain) deadlock in the system. Put forward the necessary and sufficient condition for the system without deadlock. Further, the control strategy and control algorithm with deadlock avoidance is proposed in the paper. Then Analysis and realize the key issues of deadlock control—recognise the cycle (cycle chain). The feasibility of the deadlock avoidance control strategy is testified by examples.Finally, according to the system's operation procedure and behavior, has realized the AVS/RS system's simulation model base on VC++.NET, which indicate the model of DCDT-PN and the deadlock avoidance control strategy is feasible and effective.