Agent-based simulation framework for mixed traffic of cars,pedestrians and trams

In this paper, we report on the construction of a new framework for simulating mixed traffic consisting of cars, trams, and pedestrians that can be used to support discussions about road management, signal control, and public transit. Specifically, a layered road structure that was designed for car traffic simulations was extended to interact with an existing one-dimensional (1D) car-following model and a two-dimensional (2D) discrete choice model for pedestrians. The car model, pedestrian model, and interaction rules implemented in the proposed framework were verified through simulations involving simple road environments. The resulting simulated values were in near agreement with the empirical data. We then used the proposed framework to assess the impact of a tramway extension plan for a real city. The simulation results showed that the impact of the proposed tramway on existing car traffic would not be serious, and by extension, implied that the proposed framework could help stakeholders decide on expansion scenarios that are satisfactory to both tram users and private car owners.     

基于Multi-agent的道路交通流控制模型

结合近年来出现的人工智能新技术，提出基于Ｍulti-agent的道路交通流控制模型，从而实现一种灵活的agent自主控制算法，并进一步提出Ｍulti-agent协商策略的设想，实验证明，该agent自主控制算法柔性结合多个交通状态量，较好地平衡了道路交叉口各向交通流，具有较强的优化度和扩展能力。     

铁路站段中基于多代理的分布式网络管理体系设计

从多代理系统出发,结合铁路站段组网的实际情况,提出两种适合铁路实际情况的代理模式,并对代理自身的体系结构进行分析,为铁路站段的网络管理问题探求一条行之有效的解决方法.     

基于多代理机制的列车运行调整模型及算法动态集成研究

分析列车运行调整问题研究的现状与进展,主要集中在模型研究和算法研究两个方面。分析传统求解模型及算法研究的局限性,提出对现有模型及算法进行动态集成的研究思路。采用基于多代理机制的动态集成方法,将模型对象和算法对象转化成多个代理,定义多代理之间的交互策略,实现调整方法的动态集成。提出基于多代理机制的列车运行调整问题模型及算法的动态集成系统。     

Can agents measure up? A comparative study of an agent-based and on-line optimization approach for a drayage problem with uncertainty

Experiments studying the behavior of agent-based methods over varying levels of uncertainty in comparison to traditional optimization methods are generally absent from the literature. In this paper we apply two structurally distinct solution approaches, an on-line optimization and an agent-based approach, to a drayage problem with time windows under two types of uncertainty. Both solution approaches are able to respond to dynamic events. The on-line optimization approach utilizes a mixed integer program to obtain a feasible route at 30-s intervals. The second solution approach deploys agents that engage in auctions to satisfy their own objectives based on the information they perceive and maintain locally. Our results reveal that the agent-based system can outperform the on-line optimization when service time duration is highly uncertain. The on-line optimization approach, on the other hand, performs competitively with the agent-based system under conditions of job-arrival uncertainty. When both moderate service time and job-arrival uncertainties are combined, the agent system outperforms the on-line optimization; however, in the case of extremely high combined uncertainty, the on-line optimization outperforms the agent-based approach.     

基于MAS的列车运行调整方法

针对列车运行调整问题,运用多智能体系统(MAS)技术,将列车运行调整方案的制定过程抽象为多用户(列车)对车站股道和区间线路等共享资源的占用预约过程,在此基础上建立智能体模型。车站和区间被抽象为资源Agent,列车被抽象为用户Agent,由资源Agent和用户Agent组成多Agent系统,Agent之间采用合同网协议进行协作。列车运行调整方案由Agent之间的分布式自主决策和相互协作产生。协作过程中的数据通信采用KQML标准设计,并增加消息等级,以提高通信和系统的效率。仿真实验表明,采用基于MAS的列车运行调整方法是可行的。     

铁路危险货物运输自动配装技术的研究

分析影响危险货物运输安全的各种要素,研究危险货物配装表、危险货物配装经验的规则提炼和一阶谓词逻辑描述.在此基础上,提出一种基于多Agent系统的分布式专家系统,包括基于框架和产生式规则的混合知识库设计以及基于多Agent的竞争、协同优化配装系统实现.研究表明,多Agent自动配装专家系统能够有效组织、管理和运用危险贷物运输自动配装的启发式知识,显著提高配装效率,降低配装作业技术要求,具有较高的实用价值.     

An agent-based framework for cooperative planning of intermodal freight transport chains

The recent development of Intelligent Transportation Systems offers the possibility of cooperative planning of multi-actor systems in a distributed framework, by enabling prompt exchange of information among actors. This paper proposes a modeling framework for cooperation in intermodal freight transport chains as multi-actor systems. In this framework, the problem of optimizing freight transportation is decomposed into a suitable set of sub-problems, each representing the operations of an actor which are connected using a negotiation scheme. A Discrete Event model is developed which optimizes the system on a rolling horizon basis to account for the dynamics of intermodal freight transport operations. This framework allows for an event driven short/medium term planning of intermodal freight transport chains. The proposed methodology is evaluated using a realistic case study, and the results are compared against the First-Come-First-Served strategy, highlighting the significance of cooperation in systems operating close to capacity.     

开放式智能安全代理体系架构设计

针对目前网络安全产品、技术和安全模型存在的问题，提出一种具有开放体系架构的通用智能安全代理模型。智能安全代理由插件运行管理平台和一组插件构成。插件平台包括消息解释器、路由器、黄页及黑板等组件，负责监视和管理插件的运行。利用注册／注销，代理通信、协作与委托计算机制，多个智能安全代理可以组成一个代理社区，实现分布式异构网络环境下的协同安全防御。实践表明，该模型具有良好的开放性、通用性、多功能性，以及可伸缩、可移值、智能化和面向应用等特性，可以为各类终端节点提供多种安全保护。     

Modelling lane changing and merging in microscopic traffic simulation

This paper introduces Simulation of Intelligent TRAnsport Systems (SITRAS), a massive multi-agent simulation system in which driver-vehicle objects are modelled as autonomous agents. The simulation outputs can be used for the evaluation of Intelligent Transport Systems applications such as congestion and incident management, public transport priority and dynamic route guidance. The model concepts and specifications, and the first applications of the model in the area of incident modelling in urban arterial networks were described in previous publications. This paper presents the details of the lane changing and merging algorithms developed for the SITRAS model. These models incorporate procedures for ‘forced’ and ‘co-operative’ lane changing which are essential for lane changing under congested (and incident-affected) traffic conditions. The paper describes the algorithms and presents simulation examples to demonstrate the effects of the implemented models. The results indicate that only the forced and cooperative lane changing models can produce realistic flow-speed relationships during congested conditions.