The Simulation Of A Flexible Manufacturing System Based On Petri Net & Stateflow

With the development of advanced techniques and the intensification of market competation , industry manufacturing is facing more and more stress. Flexible Manufacturing System(FMS) is a method applicable to produce variety of productions in medium or small batch. FMS can shorten producing period , reduce store volume and improve productions' quality.FMS is an advanced technique of high investment and risk. It is also a sophisticated automatic system consisting of material flow and information flow. FMS can exert its potential only if it is fully studied in its designing period, therefore it is important to supply desiding fundition by simulating the system.The paper researches a FMS on its modeling and simulation. Petri Net is good at reflecting systems' logical relationship and suitable to conduct time. It can also model systems on variable logica levels and now is used the most in modeling FMS. The paper develops a Petri Net model of the high-pressure boiler tube production line in Baosteel Tube Branch and a simulator of this system based on MATLAB/Stateflow. Stateflow can use charts to describe event-driven systems conveniently and quickly by combining Finite State Machine (FSM), state charts and flow charts together.The simulator designed can simulate the systemof the production line of Baosteel Tube Branch. The paper mainly simulates the producing process of tubes of small diameter, medium diameter and big diameter. It uses a terminational simulation method to study the producing capacity of these three types of tubes, the using rate of the machines and the occupying state of the machines' buffer-ins of the production line. It compares and optimizes the means of the arrangement of the machines and the assignment of the workers of every type of tubes. The paper also studies the optimized systems considering the random elements of the machines' failures. It gets the confidence intervals of the optimized systems' producing capacity based on 95% degree of confidence.The Petri Net model can be revised when a new project established or a new managing method added to the system. At the same time, the simulator can be easily enlarged and renewed to become a new simulator. With it we can evaluate the performance of the new system and get the decision-making support to develop the new system.