Research On Co-scheduling Of The Three Gorges And Gezhouba Dam Navigation System Based On Stochastic Petri Net

The Three Gorges and Gezhouba Dam Navigation System mainly includes three Gorges ship lock,ship lift and Gezhouba Dam ship lock.In recent years,the total freight volume of the Yangtze River basin is growing rapidly and the demand for ships crossing dam is increasing,on the other hand,the ship lift begin trial operation,the original co-scheduling strategy is showing insufficiency.In order to meet the requirement of joint navigation,to improve the navigation capacity of the system and to achieve the maximum navigation capacity of the system,so that the ship can navigate safely,stablely and orderly,the joint scheduling problem of navigation system has become a top priority.Based on the existing achievements,this paper analyzes the problem of joint scheduling,combine stochastic Petri net theory,discrete event dynamic system theory and system simulation technology,finding out the bottleneck of the system through analysis of the stochastic Petri net model,on this basis,the simulation model is built and the experiment is designed to determine the optimal joint scheduling strategy.The main achievements are as follows:(1)Based on complex system theory,this paper analyses the operation mechanism and complexity of the navigation system,combining with the complexity of the system,it analyzes the advantages and disadvantages of the existing joint scheduling strategy;Then proposes two new scheduling strategies from the chamber area utilization maximization,balance the traffic fairness and the utilization rate of chamber,then analysis them.(2)Based on the stochastic Petri net theory,A model is established to express the logical relations among entities in the system,and the model is proved to be bounded and reachable,the structural analysis of the model shows that it is bounded and reachable;On the basis,I construct a Markoff chain which is isomorphic to the model,analyze the performance of the model by solving the stable probability,and finally found the key to the navigation capacity of the system is to make a joint scheduling plan.(3)This paper combines ship lock and ship lift,then sets up the hierarchical model,object model and dynamic model of this system as the basis of simulation modeling,with the help of object-oriented modeling technology;Based on the system simulation technology,the simulation model of the Three Gorges and Gezhouba Dam navigation system is established,which can be debugged and verified in many ways to ensure the correctness and availability of the model.(4)Base on the simulation model for Three Gorges and Gezhouba Dam navigation system,The influence degree of different joint scheduling strategies on the shipping level are considered as the research questions,it puts forward a comprehensive evaluation index and determines the test conditions.Considering plans for different joint scheduling strategies as test plan,then the simulation experiment is carried out,finding out the optimal joint scheduling strategy by comparing the experimental data under different schemes.The results of this paper are oriented to the co-scheduling of navigation system,which is helpful to improve the operation scheduling and management of navigation facilities,and is easy to tap the potential of navigation system.It has some theoretical and practical value.