无损检测技术在地铁车辆检测中的应用

地铁车辆是一座城市的命脉,是推动城市发展的一根重要血管,而无损检测技术是能确保地铁车辆安全行驶的前提。这篇文章通过对无损检测技术的介绍以及中国无损检测技术的发展史和前景的了解,让大家知道无损检测技术的原理和如何对地铁车辆的安全检测;对地铁车辆的介绍和分析以及无损检测技术在地铁中如何应用和不同的无损检测技术针对不同车辆部位进行检测的最终效果。     

城市桥梁受车辆拥堵影响下的灾害与防治

车辆拥堵是造成桥梁安全与耐久性病害的重要因素之一。本文通过国内外对城市桥梁的车辆通行特点分析,分析了车辆拥堵对城市桥梁的静力影响。综合评述了不同类型车辆在拥堵状况下对桥梁的影响作用的不同。简要分析了在疲劳载荷下车辆堵塞情况下桥梁结构的失效机理,讨论了车辆堵塞对桥梁机械性能的影响。总结了国内对拥堵作用下分析的方法,提出国内对拥堵情况下的难点,并对分析方法的发展趋势做出大胆的假设。     

新型跨坐式单轨车辆的主要特点及应用

随着城市公共交通多样化的发展,单轨车辆开始更多地进入公众视线,本文主要就新型单轨车辆与传统单轨车辆的差异进行分析,以及新型单轨车辆的两种类型进行对比,对不同类型的单轨车辆从车辆外观,内饰、牵引系统、检修维护、安全性、各系统技术发展以及应用前景等方面进行了综合分析,为城市进行轨道交通制式的规划选型提供参考与借鉴。     

城市园林绿化与施工

近年来,随着经济社会的快速发展,我国人民的生活,阡显著提高,使得车辆数目猛增。过多的车辆会产生很多汽车尾气,在一定程度上加大了城市污染,受到社会广泛的关注。通过城市园林绿化工程,可以美化城市、减轻污染,为居民提供舒适的生活环境,有利于我国的低硖城市建设。     

对城市轨道交通车辆维修管理的研究

随着我国的发展和日益强大,城市轨道交通建设已经成为我国城市建设中必不可少的环节。车辆是城市轨道交通中最重要、最关键的设备,因而城市轨道交通车辆的运行安全和维修管理已经引起了人们的极大重视。为此,本文将对城市轨道交通车辆维修管理作出探讨。     

噪声伴随汽车冲进城市生活

汽车在污染大气的同时,还对周围环境形成噪声污染,据有关部门统计,2001年交通噪声污染占整个环境噪声总量的20.1%,2004年超过30%,而在车辆密集的地区,车辆噪声污染远大于此。我国部分城市的交通噪声甚至占城市噪声的75%。     

城市渣土管理中的GIS技术应用与研究

城市建设发展带来城市渣土清运过程中的城市环境、交通安全等城市管理问题,本文依据渣土管理的需要,针对渣土清运车辆的监控与管理,应用GIS技术与GPS技术实现渣土的车辆实时监控与管理,通过多种技术的集成,实现车辆超速、违规作业监管与识别,并应用电子围栏技术实现违规肇事车辆排查、车辆偷乱倒监管,实现了城市渣土车辆的规范化管理。     

城市道路早期预防性养护方法浅析

随着城市现代化进程的加快,城市基础设施建设发展迅速,快速通道及相关配套道路相继修建并通车,设施量急剧增加。但是随着车辆的增加及时间的推移,部分修建时存在问题的道路相继出现不同程度的病害。为保证行人、车辆的出行安全及道路的畅通,必须对损坏路面进行及时养护修复。     

浅析城市道路交通噪声的影响因素及其治理措施

近年来,随着我国城市汽车保有量的急剧增长,城市道路交通噪声污染越来越严重,对道路周边居民的正常生活,工作,学习和休息的干扰程度和影响范围逐步扩大,而且近几年来城市建筑施工以及城市服务行业的发展使得各种车辆的出入比以前更为频繁,提高了作业车辆和私家车辆的出行率,增加了城市道路交通噪声的污染程度。笔者从城市道路交通噪声污染的来源进行分析,探讨城市道路交通噪声的来源及组成部分,并提出相应的解决对策。     

如何解决城市行车难问题

交通是发展经济的命脉。但城市汽车超快速的发展又会给城市交通造成一定的困难;同时,过量的废气排放和噪声超标还要影响市容和环境。为此我们必须找到一条适合我国国情的发展城市现代化交通的途径。城市快速交通的理想车辆,是用电力牵引的磁浮列车。车辆不接触地面,而是用电磁力支撑起来,加速是来自电力牵引,减速或“刹     

Joint estimation of position and attitude for intelligent vehicles by fusing delayed visual measurements

Accurate position and attitude information is an important basis for normal driving of intelligent vehicles. In this paper, we investigate the estimation of position and attitude states for intelligent vehicles with low cost scheme. The low cost GNSS, camera, and proprioceptive sensors equipped by mass-produced vehicle are fused to estimate the states. The visual measurements adopted in this paper are based on the lateral distance and deflection angle to road features such as lane lines or curbs, which are generated more frequently than some other semantic features such as traffic lights, and leads to broader application scenario. Moreover, it is easier to implement compared with geometrical feature matching methods, since it only needs a simple prior map while latter needs large maps containing many high precision features. The visual measurements is often with large time delay due to negligible processing time. In order to fuse delayed measurements, a state-augmentation technique is adopted for the estimator design. The performance of the proposed method is evaluated by professional simulation software CarMaker, and shows that the incorporation of road features based visual measurement can effectively improve the position and attitude estimation accuracy by reducing the lateral position and yaw angle estimation error.     

Towards mesoscale analysis of inter-vehicle communications

Cooperative traffic systems renew much research interest with the rapid development of communication technologies. This paper considers a finite number of vehicles moving in a single lane from a mesoscale perspective and explores the spectral properties of such a cooperative system, in particular how the communication range and the coupling weights influence the eigenvalues of the global disturbance transition matrix (DTM), i.e., disturbance modes of the traffic system. Dynamics of these vehicles are described by a modified coupled-map car-following model under periodic boundaries with inter-vehicle communications. From a state-space approach, a system DTM is established from a global view and a closed-form solution of its eigenvalues is derived. Linear stability conditions are subsequently obtained. It is found that the eigenvalue distribution of system DTM is essentially dominated by the communication range and the coupling weights, but nearly independent of the system size. By analyzing the magnitudes of the dominant poles, the synchronization of the traffic system is enhanced if the weights of the vehicles within the communication range are more evenly distributed or the communication range is increased. Particularly, it is shown that the optimal communication network tends to be a mean-field network w.r.t. global synchronization, indicating that a communication network emphasizing uniform importance among vehicles within each vehicle’s communication range is helpful for improving the synchronizability. Finally, numerical simulations verify the results.     

基于动态交通流量的可变车道自适应控制方法

为解决目前可变车道多为手动定时控制、感应控制而引起的可变车道利用率不高以及控制精度不高的问题,首先对影响可变车道属性的因素进行分析,然后以实时的交通流量数据为基础,提出了一种基于动态交通流量的可变车道自适应控制方法,实时地改变可变车道的属性,充分利用可变车道,提高信号交叉口的通行能力。PARAMICS仿真结果表明,该方法能够提高可变车道的利用率,减小信号交叉口的交通延误。     

Robust gain-scheduled output feedback yaw stability control for in-wheel-motor-driven electric vehicles with external yaw-moment

This paper presents a robust gain-scheduled output feedback yaw stability H_∞ controller design to improve vehicle yaw stability and handling performance for in-wheel-motor-driven electric vehicles. The main control objective is to track the desired yaw references by managing the external yaw moment. Since vehicle lateral states are difficult to obtain, the state feedback controller normally requires vehicle full-state feedback is a critical challenge for vehicle lateral dynamics control. To deal with the challenge, the robust gain-scheduled output feedback controller design only uses measurements from standard sensors in modern cars as feedback signals. Meanwhile, parameter uncertainties in vehicle lateral dynamics such as tire cornering stiffness and vehicle inertial parameters are considered and handled via the norm-bounded uncertainty, and linear parameter-varying polytope vehicle model with finite vertices is established through reducing conservative. The resulting robust gain-scheduled output feedback yaw stability controller is finally designed, and solved in term of a set of linear matrix inequalities. Simulations for single lane and double lane change maneuvers are implemented to verify the effectiveness of developed approach with a high-fidelity, CarSim^®, full-vehicle model. It is confirmed from the results that the proposed controller can effectively preserve vehicle yaw stability and lateral handling performance.     

Fuzzy steering control for autonomous vehicles under actuator saturation: Design and experiments

This paper presents a new control method for autonomous vehicles. The design goal is to perform the automatic lane keeping under multiple system constraints, namely actuator saturation of the steering system, roads with unknown curvature and uncertain lateral wind force. Such system constraints are explicitly taken into account in the control design procedure. To achieve this goal, we propose a new constrained Takagi–Sugeno fuzzy model-based control method using fuzzy Lyapunov control framework. The resulting non-parallel distributed compensation controller is able to handle not only various system constraints but also a large variation range of vehicle speed. In particular, Taylor’s approximation method is exploited to reduce not only the numerical complexity for real-time implementation but also the conservatism of the results. The design conditions are strictly expressed in terms of linear matrix inequalities which can be efficiently solved with available numerical solvers. The effectiveness of the proposed control method is demonstrated through both simulation and hardware experiments with various driving scenarios.     

新能源汽车产业的政策保护与利基构建——基于多层次产业演化的分析

依据产业演化观点,将新能源汽车视为是在原有交通运输体系中出现的利基,探究社会技术体系的转变和产业政策的保护性作用对新能源汽车利基演化的影响。研究结果表明,在利基层次上,存在着新能源汽车技术利基向市场利基的演化过程,且技术利基宽度与市场利基宽度显著正相关。在社会技术体系层次上,一方面产业政策所形成的保护性空间有助于新能源汽车技术转化,另一方面反映社会技术转变的因素对新能源汽车利基的形成具有显著影响,其中新能源汽车产销比和废气治理投入与市场利基的形成负相关,而燃油价格、消费者购买力和基础设施建设水平与市场利基的形成正相关。据此提出根据产业演化阶段和层次设计产业政策的思路和方案。     

Robust stabilization of balanced and splay formations with heterogeneous controller gains

This paper analyses collective motion of multi-vehicle systems in balanced or splay formation when the vehicles are equipped with heterogeneous controller gains. Balancing refers to a situation in which the positional centroid of the vehicles is stationary. The splay formation is a special case of balancing in which the vehicles are spatially distributed with equal angular separation between them. The paper proposes strategies to achieve such balanced and splay formations about a desired centroid location while allowing the vehicles to move either along straight line paths or on individual circular orbits. Feedback control laws that can tolerate heterogeneity in the controller gains, which may be caused by imperfect implementation, are derived and analyzed. It is shown that drastic failures leading to controller gains becoming zero for almost half of the vehicles in the group can be tolerated and balanced formation can still be achieved. On the other hand, splay formation can still be achieved if the controller gain is zero for at most one vehicle. Simulation examples are given to illustrate the theoretical findings.     

基于PROTEUS设计的智能交通灯控制系统

本文分析了现代城市交通信号灯控制与管理的不合理性,进而提出一款更具人性化、智能化的城市交通灯控制系统的软硬件电路设计方案.该方案突破了传统固定时间模式,能根据车流量大小自动调节车辆通行时间,并考虑特殊车辆设置了紧急通道转换开关.最后通过PROTEUS仿真说明了系统制作过程与调试结果.     

如何根据产量规模合理地确定矿井大巷运输方式

文章介绍了矿井大巷的主要运输方式及其优缺点,经过对两种不同运输方式的运输能力和运营费用等方面,进行经济技术分析、对比后,阐明运输方式的选择与矿井产量规模的关系,合理确定矿井大巷运输方式。     

矿井大巷运输方式的选择

介绍了矿井大巷的主要运输方式及其优缺点,经过对两种不同运输方式的运输能力和运营费用等方面进行经济技术分析、对比后,阐明运输方式的选择与矿井产量规模的关系,合理确定矿井大巷运输方式。