基于PFV策略的连续型元胞自动机交通流模型

科学合理的微观交通流仿真模型是研究交通控制手段有效性的关键.本文结合一种考虑驾驶员视野内前后多车影响的跟驰策略，建立了连续型元胞自动机交通流模型.仿真实验表明，仿真数据与实测数据有较好的拟合性，仿真得到的 K-Q、K-V和 Q-V图能较好地反映实际道路交通流的失稳现象，所建立的模型具有适应不同场景的兼容性与灵活性，能够作为研究我国实际道路交通流问题的仿真工具.     

基于宏观基本图的路网多子区状态一致协同控制

针对基于宏观基本图(MFD)的路网多子区协同控制未考虑各子区拥堵状态差异性及均衡性的问题，本文提出以多子区状态可达一致为目标的子区边界状态反馈控制设计方法. 首先，基于路网 MFD模型建立路网多子区协同模型；进一步，基于部分变量稳定性理论，设计多子区状态可达一致的边界状态反馈控制律.在此基础上，考虑子区拥堵状态的差异性，设计了子区间的协同控制策略，快速缓解子区拥堵状态；同时，提出子区边界输入流的分配优化策略.最后，以潍坊市实际路网为背景建立仿真模型.实验结果表明，本文方法可实现子区交通流分布的均衡性，快速缓解子区拥堵状态，较大幅度地提升路网运行效率.     

Asynchronous n-step Q-learning adaptive traffic signal control

Ensuring transportation systems are efficient is a priority for modern society. Intersection traffic signal control can be modeled as a sequential decision-making problem. To learn how to make the best decisions, we apply reinforcement learning techniques with function approximation to train an adaptive traffic signal controller. We use the asynchronous n-step Q-learning algorithm with a two hidden layer artificial neural network as our reinforcement learning agent. A dynamic, stochastic rush hour simulation is developed to test the agent’s performance. Compared against traditional loop detector actuated and linear Q-learning traffic signal control methods, our reinforcement learning model develops a superior control policy, reducing mean total delay by up 40% without compromising throughput. However, we find our proposed model slightly increases delay for left turning vehicles compared to the actuated controller, as a consequence of the reward function, highlighting the need for an appropriate reward function which truly develops the desired policy.     

提高磁浮交通供电系统功率因数的措施

针对上海高速磁浮交通供电系统的滤波、无功补偿设计的特点,分析了供电系统功率因数较低的原因,提出了提高功率因数的技术措施,并分析了该措施的技术、经济效益。最后给出了改进滤波、补偿系统设计的建议。     

面向传染病疫情防控的公共交通运行管理决策支持研究

近年来全球新发重大传染病疫情不断出现，已成为人类社会必须防范应对的重大风险。公共交通在传染病疫情防控过程中承担着阻断病毒传播和保障复工复产的功能，疫情期间公共交通运行管理的决策需求和技术支撑体系与日常情况有显著差异。现有研究多针对公交日常运行决策需求展开，虽有少量针对突发公共事件的应急管理决策支持的研究，但多针对自然灾害和事故灾难场景，无法迁移应用于传染病疫情防控。基于此，以新型冠状病毒肺炎（COVID-19）疫情为例，综合考虑突发公共卫生事件应急管理流程和疫情防控实际情况，系统梳理疫情不同阶段的防控目标和决策需求，提出一种面向传染病疫情防控的公共交通运行管理决策支持系统框架，建立基于公共卫生事件案例库、多源数据融合库、公交数据分析技术库和公交防疫策略库的功能架构，并设计不同功能模块的算法模型。研究以厦门为例，对提出的决策支持系统的功能架构和算法模型进行验证。研究结果表明，构建公交乘客出行链的成功率为89.7%，并可应用于疫情不同阶段的关联客流分析、感染者同乘人员的追溯分析、医护人员等防疫人员的通勤出行识别、公交运行满载率监控等方面。研究成果不仅对传染病疫情防控有实用价值，而且对突发公共事件应急管理决策支持方法亦有理论贡献。     

交通运输企业伦理的基本维度研究

交通运输企业伦理是运输企业在生产经营活动中所确认并遵循的价值观念与行为方式。文章运用抽象方法,对交通运输企业的＂安全、便捷、文明、生态＂四个基本原则进行了深入分析,旨在为运输企业的伦理化运营提供理论指向。     

An evaluation framework for traffic calming measures in residential areas

The paper evaluates the effectiveness of various traffic calming measures from the perspectives of traffic performance and safety, and environmental and public health impacts. The proposed framework was applied to four calming measures – two types of speed humps, speed tables, and chicanes – to demonstrate its usefulness and applicability. A field experiment using probe vehicles equipped with global positioning system devices was conducted to obtain vehicle trajectory data for use in more realistic simulations. In addition, a recently developed vehicle emissions model was used for more accurate evaluation of environmental and public health impacts. The results show that chicane is better than the other types of traffic calming measures considered, except in terms of vehicle emissions.     

Vibration control in train–bridge–track systems

To study the problems associated with vibration control of train–bridge–track systems a mathematical model with the capability of representing supplementary vibrational control devices is proposed. The train system is assumed as rigid bodies supported on double-deck suspension mechanism with semi-active features. The bridge system is modeled using the modal approach. Vibration control for bridge responses is provided by tuned mass dampers. A non-classical incremental Eigen analysis is proposed to trace the system characteristics across the time. In an example, the capability of the proposed model in investigating the vibration control prospects of a bridge–train system is shown. The results indicate the effectiveness of active suspension mechanism in reducing train's body movements, particularly the pitching angle and the vertical accelerations. Accordingly, the results also verify the potential of TMD devices in reducing the bridge responses at resonance motions.