Model reformulation for conflict-free routing problems using Petri Net and Deterministic Finite Automaton

摘要

It is well known that routing problems are recast as a binary integer linear programming in overhead hoist transport (OHT) vehicle systems. Two kinds of discrete-time state space models of the routing problem are proposed in this paper that simplifies the constraints and binary variables. First, a Petri Net (PN) method is used to simplify the constraints. Second, a Deterministic Finite (DF) Automaton method is used for reducing the binary inputs of the state space equation in OHT systems. Finally, some numerical examples are shown to verify the validity of the proposed methods.