基于居民出行时耗与出行比例关系的OD矩阵估算新方法

建立了基于居民出行时耗与出行比例关系的OD矩阵估算新方法，该方法依据出行时耗分布规律进行，将小区出行量离散为不同出行时耗区间的出行量，并根据出行时耗区间所覆盖的交通吸引小区的面积及吸引量进行交通分布，方法运用中还可根据城市不同区域交通特征调整区域居民出行时耗分布，从而克服了重力模型OD估算结果与出行时耗特征不一致及模型参数全局不变等缺点。实例证明了该方法优于重力模型OD矩阵估算精度。     

城市出行特征分析

城市居民出行特征及货物流动特征是与交通运输系统及其应用相关的,它对于研究规划过程中的技术分析和战略类型非常重要。文中根据近年来的调查数据,从出行目的、出行时间分配两方面分析了城市出行的变化特征,提出了出行链的概念,探讨了客运交通发展战略。     

居民全日出行方式选择动态模型研究

为改进现有交通方式选择模型,提高交通方式预测模型精度,基于出行链建立了居民全日出行方式选择动态模型。从居民出行方式选择机理分析入手,确立出行方式选择动态影响因素,在多项Logit模型（MNL模型）的基础上建立了方式选择动态模型。模型中增加了2类动态影响因素,即先前出行方式选择结果对后面出行方式选择的影响和主链的出行方式选择结果对子链出行方式选择的影响。最后以安徽省淮北市为例对模型进行了实例分析。结果表明：所建立的动态模型的优度比和预测准确率较基于单次出行效用的MNL模型有较大提高,变量在模型中的意义符合中国国情,模型可服务于城市交通规划和交通政策制定。     

苏州居民通勤出行交通方式选择特征研究

通过对苏州居民出行调查中有关通勤出行的信息进行分析计算,研究了通勤出行交通结构、不同人群交通方式选择特征以及通勤交通方式的出行距离特征,该分析结果有助于城市交通发展规划,特别是针对城市居民上下班出行的交通政策的制定和交通系统的设计。     

不同出行方式交通空间颗粒物浓度特征及人体摄入量估算方法研究

为了提高居民出行健康,建立了评估出行者采用不同出行方式时的PM人体摄入量估算方法体系.使用PM检测仪采集各出行方式(步行、自行车、公交、出租车、地铁)不同交通空间(包括车厢、站台、人行道等出行者在出行过程中身处的周围环境空间)的PM浓度,建立了基于多元线性回归的PM浓度与影响因素的关系模型,并考虑出行个体心率指标的变化...     

基于MNL模型的居民出行方式选择行为研究——以南方某小城市为例

为明确城市居民出行方式选择的关键影响因素，调节城市居民出行结构，提高城市交通系统效率，以南方某小城市居民出行数据为研究对象，基于随机效用最大化理论构建多项MNL(Multinomial Logit)模型，分析了个人属性、家庭属性和出行方案属性对出行方式选择产生的作用。通过分析MNL模型统计回归结果，得出以下结论：1)个人属性中，年龄、性别、个人月收入、受教育程度、驾照拥有情况对居民出行方式选择行为有显著影响；2)家庭属性中，住户小汽车拥有情况和摩托车拥有情况对居民出行方式选择行为有显著影响；3)出行属性中，出行时间和出行目的对居民出行方式选择行为有显著影响，而出行费用在出行选择过程中没有显著作用。     

通勤者出行方式与出行链选择行为研究

通过分析2005年北京市居民出行调查数据,构造通勤者上班出行方式选择和出行链类型选择相互影响的NestedLogit模型,分别建立出行方式→出行链和出行链→出行方式两个方向模型结构,采用统计软件STATA9.0对模型进行标定,并利用包容系数对Nested Logit模型的结构关系进行辨识。结果表明,出行方式选择和出行链类型选择之间不是单方向影响关系,而是一种双向的相互作用关系;出行链→出行方式选择决策较为合理,反应通勤者倾向于首先考虑如何组织当天要参加的各种活动,然后在出行链安排的约束下考虑选择合适的出行方式。     

杭州市居民出行特征分析及交通发展对策探讨

该文根据杭州市2005年居民出行调查的相关数据,结合杭州市城市交通现状,对杭州市居民出行次数、出行时段、出行方式等一系列的指标进行了分析研究,总结归纳杭州市居民出行特征的规律、变化特征及其原因,并在此基础上对杭州市的交通发展提出相关的建议。     

居民公交出行链重复性量化分析及其出行规律研究

作为城市交通的枢纽，公共交通系统承载了大量的居民出行。自动数据采集系统收集的IC卡数据包含了大量的乘客出行信息，通过这些数据可分析居民公交出行规律，进而优化公交服务。引入信息熵及熵率对居民公交出行链重复性进行量化，研究了基于量化指标分析居民公交出行规律的方法。通过出行地点状态标定，将乘客的出行链转化为离散的出行序列；利用信息熵和熵率对出行序列进行量化分析，得到出行重复性与量化指标的关系，即出行序列的信息熵越大，熵率越小，该乘客出行重复性越高，出行规律越强。基于重复性量化处理，以石家庄公交智能卡乘客出行数据为例，分别从群体和个人这2个方面对公交乘客的出行规律进行分析。结果表明，出行链重复性量化指标可以对出行规律的强弱进行直观判断。当乘客出行规律不明显，但信息熵高于样本均值2.53 bits、熵率低于样本均值1.13 bits/事件时，可通过进一步分析挖掘出乘客潜在出行规律。      

基于大数据的出行方式分配预测研究

随着城镇化及城市交通机动化的进程加快，在城镇化和机动化的共同作用下，交通拥挤问题已经成为制约城市发展和影响居民生活质量的主要问题之一。居民出行行为研究在交通管理和控制中有着非常重要的作用。结合多元大数据，构建出行方式选择的概率模型，有助于不同小区的出行方式分担率的预测，对缓解城市交通压力、提升运营管理能力有直接作用。本文基于小区出行分配、公共交通和非公共交通以及公交和轨道出行三个层级，分别得出出行分配预测模型，并形成计算机程序。利于实际应用，对识别城市出行特征、缓解城市交通压力提供有效措施。     

边坡位移预测的混沌时间序列分析方法应用研究

把混沌时间序列理论引入到边坡工程研究中，运用边坡位移时间序列的最大Lyapunov指数预测边坡的变形破坏，建立了预测模型，并结合工程实例进行边坡位移预测，取得了较好的预测效果。     

Hybrid modelling and damping collaborative optimisation of Five-suspensions for coupling driver-seat-cab system

For the complex structure and vibration characteristics of coupling driver-seat-cab system of trucks, there is no damping optimisation theory for its suspensions at present, which seriously restricts the improvement of vehicle ride comfort. Thus, in this paper, the seat suspension was regarded as ‘the fifth suspension’ of cab, the ‘Five-suspensions’ for this system was proposed. Based on this, using the mechanism modelling method, a 4 degree-of-freedom coupling driver-seat-cab system model was presented; then, by the tested cab suspensions excitation and seat acceleration response, its parameters identification mathematical model was established. Based on this, taking optimal ride comfort as target, its damping collaborative optimisation mathematical model was built. Combining the tested signals and a simulation model with the mathematical models of parameters identification and damping collaborative optimisation, a complete flow of hybrid modelling and damping collaborative optimisation of Five-suspensions was presented. With a practical example of seat and cab system, the damping parameters were optimised and validated by simulation and bench test. The results show that the model and method proposed are correct and reliable, providing a valuable reference for the design of seat suspension and cab suspensions.     

Optimal Adaptive Active Suspensions for a Full Car Model

In order to present a useful method for designing active suspension of a vehicle, a linear full-car model is used in this investigation. In this model, the dampers of passive system are totally replaced by actuators. The actuators are controlled with optimal full state vector feedback. After determining feedback coefficients, the responses of active and passive systems were compared and it was found that performance of active system is much superior. It is desired that, changes in vehicle parameters would not affect the system's performance and hence should not violate its optimality. In other words, the system should behave adaptively using Model Reference Adaptive Control. The optimally controlled active suspension was used as a model for the active suspension of vehicle. In this way, the suspension of vehicle is controlled in such a way that its output approaches to that of the optimal active model. Thus the suspension should behave just like the optimal one.     

Dynamic tyre friction models for combined longitudinal and lateral vehicle motion

An extension to the LuGre dynamic friction model from longitudinal to longitudinal/lateral motion is developed in this paper. Application of this model to a tyre yields a pair of partial differential equations that model the tyre-road contact forces and aligning moment. A comparison of the steady-state behaviour of the dynamic model with existing static tyre friction models is presented. This comparison allows one to determine realistic values of the parameters for the new dynamic model. Via the introduction of a set of mean states we reduce the partial differential equations to a lumped model governed by a set of three ordinary differential equations. Such a lumped form describes the aggregate effect of the friction forces and moments and it can be useful for control design and online estimation. A method to incorporate wheel rim rotation is also proposed. The proposed model is evaluated by comparing both its steady-state as well as its dynamic characteristics via numerical simulations. The results of the simulations corroborate steady-state and dynamic/transient tyre characteristics found in the literature.     

车辆换挡过程的离合器仿真研究

离合器是车辆传动系统的重要部件,在车辆行驶过程中它的接合与分离频繁,对它的控制是目前研究的重点之一。建立了整车模型中离合器的动力学仿真模型,分析了换挡过程中离合器的控制问题,在其控制策略中对离合器的控制与换挡动作进行了协调,并且综合考虑了换挡品质的三个评价指标;最后,运行建立的整车模型,在整车模型中进行验证,得到了换挡过程中与离合器相关的系列曲线,取得了较好的效果。     

汽车造型设计实物验证模型材料选择应用研究

汽车造型设计实物验证是汽车开发流程中重要的内容。文章概述了目前汽车造型设计实物验证模型制作过程中的材料应用情况,分析了应用在实物验证模型中各主流材料的加工特性及其在具体模型制作过程中的优缺点,阐述了如何针对不同开发阶段汽车造型验证模型制作的要求和特点,合理选择正确的材料应用于验证模型和样件的制作,以最低的成本和最环保的方式获得最佳的效果。     

受限路网中汽车行驶最优路径算法及优化实现

实际交通网络不仅包含路网的拓扑关系，还存在大量交通禁行限制。考虑了交通连通性约束所建立的受限路网模型能够更精确地反映实际交通网络。文中提出一种能够在受限路网中寻路的最优路径算法，并具体讨论了算法的优化实现。应用表明该算法可靠高效，可用于实际受限交通网络最优路径规划。     

Yaw damper modelling and its influence on railway dynamic stability

This paper deals with the modelling of yaw dampers and determining the influence of the modelling of this component on the results obtained when predicting the dynamic stability of a vehicle. The first part of the work analyses the influence of the yaw damper characteristics on railway dynamic stability. Following this, a physical model of the damper is developed which allows its performance to be reproduced accurately in the whole range of operating conditions the damper is envisaged to operate in. Once obtained, it was found that the computational cost of the model was relatively high. Therefore, a simplified model has been developed. The simplified model allows obtaining accurate results without excessively increasing the time required to perform the simulations. Analysing the results obtained with this model, it has been concluded that with respect to previous model based on conventional approaches, it improves the accuracy of dynamic calculation for the stability assessment. Also, it has been found that the accurate modelling of the yaw damper is critical when dealing with the vehicle's dynamic performance. In the last part of the paper, a special type of yaw damper was studied as well as its effect on the dynamic behaviour of the vehicle.     

物流外包的效益及外包区域分析

首先从物流运作总成本的角度,以资产专用性为决策变量,利用威廉姆森的启发性模型探讨了物流外包的费用效益———采购成本与交易费用的节省而产生的效益。其二,从收益增加的角度,分析了外包效益。本文认为,随着合作性关系的建立,关系性资产的形成,企业将物流业务外包给专业化的第三方物流企业,可以以更高的顾客服务水平以及更低的总物流运作成本为企业带来更多的市场销售(与内部自营物流相比)。在探讨外包效益的同时,分析了物流外包的可选择区域。