| With the development of sharing economy,car-sharing has gradually developed and expanded in scale,and more and more car-sharing companies have emerged.However,many problems need to be solved to better operate car-sharing in cities,including but not limited to vehicle configuration,station location,etc.some researchers use simulation for research.However,due to the great differences in the simulation systems required in different scenarios,the simulation systems used or developed have the problems of single applicable scenario and poor expansibility,which are difficult to reuse and adapt,However,there is no simulation system with good reusability and applicability specially adapted to car-sharing.In order to meet the diverse simulation needs of car-sharing,reduce the workload of simulation development and improve the efficiency of simulation,this paper designs and implements a modular simulation system of car-sharing based on queuing network structure,which can simulate the car-sharing network in multiple simulation scenes.First,this paper establishes a generalized simulation model of car-sharing system,which adapts to various car-sharing simulation requirements from the model level.The model is based on the queuing network structure and regards the car-sharing system as a discrete event system,which is driven by discrete events.The model is divided into four parts: common attributes,common events,model attributes,and model events.Among them,the common attributes and common events mainly describe the attributes and events related to the two queuing processes of the user’s car pickup at the station and the user’s car use on the route.All car-sharing networks using this system have these characteristics,while model attributes and model events can be customized and extended according to different simulation scenarios.Then this paper establishes a generalized simulation optimization model,which is used to output the optimization scheme under different optimization objectives.Then,based on this model,this paper designs a simulation system architecture with high applicability and low coupling degree for different service modes and simulation models of car-sharing.This architecture can be extended for various simulation requirements and has good simulation performance.Its applicability is mainly due to the development of common attributes and common events,and the realization of model attributes and model events can be defined,added or modified in the system according to changes in simulation scenarios.At the same time,this paper provides the default implementation of some common shared car simulation scenarios in the form of options,which further improves the applicability of the system.Its low coupling degree is mainly realized through modular design: the simulation system is divided into multiple functional modules,including five modules of simulation core,input and output,data statistics,simulation optimization,and simulation toolset.The interaction between modules is independent of each other through interfaces,so they can be modified or replaced without affecting other modules,thus ensuring a low degree of coupling between modules.On the basis of the above model and architecture,this paper implements a common singleride shared vehicle operation simulation system.The simulation system provides an interactive interface to support users in simulation settings and input and output,which can meet the simulation needs of various service modes and simulation models of shared cars,and can also perform iterative simulation optimization,parallel simulation,offline navigation,data custom collection and export,etc.Then,this paper verifies the reliability of the system,and makes scalability evaluation and performance comparison evaluation.The results show that the simulation system has good reliability,scalability and simulation efficiency.Finally,the simulation steps of the system are introduced and the simulation results are used. |
