Automatic Matching of Multi-scale Road Networks under the Constraints of Smaller Scale Road Meshes

In this paper,we propose a new method to achieve automatic matching of multi-scale roads under the constraints of smaller scale data.The matching process is:Firstly,meshes are extracted from two different scales road data.Secondly,several basic meshes in the larger scale road network will be merged into a composite one which is matched with one mesh in the smaller scale road network,to complete the N∶1(N>1)and 1∶1 matching.Thirdly,meshes of the two different scale road data with M∶N(M>1,N>1)matching relationships will be matched.Finally,roads will be classified into two categories under the constraints of meshes:mesh boundary roads and mesh internal roads,and then matchings between the two scales meshes will be carried out within their own categories according to the matching relationships.The results show that roads of different scales will be more precisely matched using the proposed method.

General Torsional Stiffness Matching of Off-road Vehicle

Increasing frame torsional stiffness of off-road vehicle will lead to the decrease of body torsional deformation, but the increase of torsional loads of frame and suspension system and the decrease of wheel adhesive weight. In severe case, a certain wheel will be out of contact with road surface. Appropriate matching of body, frame and suspension torsional stiffnesses is a difficult problem for off-road vehicle design. In this paper, these theoretically analytic models of the entire vehicle, body, frame and suspension torsional stiffness are constructed based on the geometry and mechanism of a light off-road vehicle＇s body, frame and suspension. The body and frame torsional stiffnesses can be calculated by applying body CAE method, meanwhile the suspension＇s rolling angle stiffness can be obtained by the bench test of the suspension＇s elastic elements. Through fixing the entire vehicle, using sole timber to raise wheels to simulate the road impact on a certain wheel, the entire vehicle torsional stiffness can be calculated on the geometric relation and loads of testing. Finally some appropriate matching principles of the body, frame and suspension torsional stiffness are summarized according to the test and analysis results. The conclusion can reveal the significance of the suspension torsional stiffness on off-road vehicle＇s torsion-absorbing capability. The results could serve as a reference for the design of other off-road vehicles.

Road traffic states estimation algorithm based on matching of regional traffic attracters

To effectively solve the traffic data problems such as data invalidation in the process of the acquisition of road traffic states,a road traffic states estimation algorithm based on matching of the regional traffic attracters was proposed in this work.First of all,the road traffic running states were divided into several different modes.The concept of the regional traffic attracters of the target link was put forward for effective matching.Then,the reference sequences of characteristics of traffic running states with the contents of the target link's traffic running states and regional traffic attracters under different modes were established.In addition,the current and historical regional traffic attracters of the target link were matched through certain matching rules,and the historical traffic running states of the target link corresponding to the optimal matching were selected as the initial recovery data,which were processed with Kalman filter to obtain the final recovery data.Finally,some typical expressways in Beijing were adopted for the verification of this road traffic states estimation algorithm.The results prove that this traffic states estimation approach based on matching of the regional traffic attracters is feasible and can achieve a high accuracy.

基于匹配置信度的路网几何特征融合方法研究

路网几何融合是维护路网数据现势性的重要手段。目前,路网融合的相关研究侧重于对匹配算法、融合策略的改进与提升,多源路网数据融合的具体方案较少。本文结合全球测图项目的迫切需求,提出了一种基于匹配置信度的路网几何特征融合方法。通过多特征因子匹配方法识别同名路网实体,设计路网匹配置信度提取增量路网数据,利用路网接边修复融合路网。实际生产应用表明,文中提出的方法在较大程度上提升了原始路网的完整性及现势性。

基于轨迹扰动和路网匹配的位置隐私保护算法

针对现有扰动机制未考虑位置点语义关系导致数据可用性较低的问题,提出一种基于差分隐私(DP)的轨迹位置隐私保护机制(DP-TLPM)。首先,DP-TLPM利用滑动窗口提取轨迹停留点生成模糊区域,再利用指数机制和拉普拉斯机制对该区域进行采样;其次,为了消除采样点中可能存在的无语义位置点,提出一种路网匹配算法,对轨迹分段并利用误差椭圆匹配(EEM)进行迭代匹配;最后,根据匹配后的位置点形成扰动轨迹,由用户端将扰动轨迹发送至服务器。实验以混淆质量和均方根误差(RMSE)为评价标准对该机制进行综合评测。与GeoInd算法相比,DP-TLPM的数据质量损失降低了24%,轨迹的混淆质量提高了52%,从隐私保护强度和数据质量两方面验证了该算法的有效性。

基于CRITIC方法的OpenStreetMap路网匹配

OpenStreetMap(OSM)数据具有更新速度快、易获取等优点,已成为城市道路数据更新的重要数据源之一。采用OSM数据对城市道路数据更新,其中OSM与已有路网数据间的匹配是关键技术之一。现有路网匹配方法中,常采用几何相似因子及其权重来实现路网间的匹配,但这些方法大多使用固定的几何相似因子权重来处理整个数据集。相比于专业路网数据,OSM数据具有明显的非系统性形变特征,采用现有方法处理OSM与专业路网间的匹配时,匹配精度较低。为了提高OSM路网与专业路网的匹配精度,提出一种基于CRITIC方法的OSM路网匹配方法,该方法针对OSM路网数据的非系统性形变特征,选用CRITIC方法自动计算得到每个道路要素的距离、面积和方向这3个几何相似因子权重,减少人为定权的局限性。通过实验验证,文中匹配方法在OSM路网的匹配中取得了较好的效果,匹配精度较高。匹配的准确率、召回率、F1分数分别达到了96.73%、98.67%和97.68%。

基于局部信息的服务迁移路径选择算法

随着移动边缘计算技术的高速发展,提供高质量的移动服务需要根据用户实时的移动轨迹变化多元地考虑网络通信中的影响因素来动态地规划服务迁移路径。针对现有服务迁移路径规划研究中对城市场景下用户移动轨迹预测缺失、规划迁移路径与用户移动路径相似度较低等问题,提出一种根据用户实时移动轨迹的服务移动路径选择算法。首先通过基于长短期记忆(LSTM)模型的轨迹预测算法和基于隐马尔可夫模型(HMM)的路网匹配算法预测用户未来移动轨迹,然后根据预测移动轨迹与邻近局部基站状态信息选择最佳迁移边缘服务器,进而完成城市场景下基于网格地图的服务迁移路径选择。在深圳市出租车轨迹数据集与手机基站状态数据集所构造的数据集上,相较于改进深度优先搜索(DFS)算法、改进A*算法、基于矩阵的动态多路径选择(MDMPS)算法和基于矩形区域划分的服务迁移路径选择(GDSMPS)算法,所提算法的平均服务迁移时间分别减少了34.8%、44.5%、24.9%和12.7%,平衡路径相似度分别提升了26.2%、49.7%、14.3%和4.7%;在噪声数据集和长路径数据集上,所提算法的平均服务迁移时间波动幅度最小且平均轨迹相似度最高。实验结果表明,所提算法不仅可以有效减少服务迁移时间,提升迁移路径与用户移动路径的相似度,而且具有良好的抗数据噪声能力与优秀的长路径规划能力。

A Method of Road Data Aided Inertial Navigation by Using Learning to Rank and ICCP Algorithm

As an independent navigation method,inertial navigation system(INS)has played a huge advantage in a lot of special conditions.But its positioning error will accumulate with time,so it is difficult to work independently for a long time.The vehicle loaded with the inertial navigation system usually drives on the road,so the high precision road data based on geographic information system(GIS)can be used as a bind of auxiliary information,which could correct INS errors by the correlation matching algorithm.The existing road matching methods rely on mathematical models,mostly for global positioning system(GPS)trajectory data,and are limited to model parameters.Therefore,based on the features of inertial navigation trajectory and road,this paper proposes a road data aided vehicle inertial navigation method based on the learning to rank and iterative closest contour point(ICCP)algorithm.Firstly,according to the geometric and directional features of inertial navigation trajectory and road,the combined feature vector is constructed as the input value;Furthermore,the scoring function and RankNet neural network based on the features of vehicle trajectory data and road data are constructed,which can learn and extract the features;Then,the nearest point of each track point and its corresponding road data set to be matched is calculated.The average translation between the two data sets is calculated by using the position relationship between each group of track points to be matched and road points;Finally,the trajectory data set is iteratively translated according to the translation amount,and the matching track point set is obtained when the trajectory error converges to complete the matching.During experiments,it is compared with other algorithms including the hidden Markov model(HMM)matching method.The experimental results show that the algorithm can effectively suppress the divergence of trajectory error.The matching accuracy is close to HMM algorithm,and the computational efficiency can meet the requirements of the traditional matching algorithm.

高精地图道路交叉口拓扑连接问题的分析方法与实践

随着高精度地图数据在自动驾驶行业中的广泛应用,针对自动驾驶行业高精度地图道路交叉口在应用过程中存在拓扑连接的问题,本文结合自动驾驶项目,提出了一种基于不同道路场景特征快速发现道路交叉口拓扑连接问题的逻辑算法。采用道路交叉口内部连接算法,能较好地识别出道路交叉口各类遗漏连接的场景,实现了对大部分场景的有效识别和防护。基于几个城市地图数据的试验结果表明,本文的逻辑算法不仅可以快速有效地挖掘出道路交叉口内拓扑连接问题,还能提前识别出试验室仿真和实车测试因为拓扑连接问题造成的地图断点问题。研究结果可以应用到自动驾驶领域的地图质检、仿真、测试等工序内,减少了自动驾驶降级次数,提升了用户体验,对后续自动驾驶道路交叉路口技术改进和感知能力提升有一定的借鉴意义。

塔吉克斯坦口音的俄语语音特点

俄语在苏联时期是整个联盟及联盟各民族间的主要交际语言,由于苏联时期对俄语的大力推行,俄语成为世界上使用人数最多的几种语言之一。近年来,中国同塔吉克斯坦的交往日益密切,随着“一带一路”倡议的提出与践行,赴塔吉克斯坦从事援助或经营项目及商务往来的公司及个人与日俱增,翻译在其中起到了重要的作用。该文论述了塔吉克斯坦口音俄语在语音层面上的特点,分别从语音(辅音、元音)、语调两个方面分析了带塔吉克斯坦口音的俄语的语音特点,并希望借此为在塔吉克斯坦学习和工作的人员分辨和校正不正确口音提供帮助,以及为中亚相关问题研究者提供参考。

混合动力越野车辆动力传动系统匹配分析

文章分析了混合动力技术在越野车辆的应用优势,并对不同混合动力构型进行优劣性分析,根据越野车辆的实际战术需求,通过调查问卷形式,采用AHP层次分析法及加权计算法,确定了串联式混合动力构型为较优动力驱动形式。基于该混合动力构型,结合整车动力性能及纯电续驶里程的要求,提出了相应车辆动力传动系统匹配方案,并利用Cruise软件进行动力性仿真计算,验证了此方案的可行性。文章对混合动力越野车辆的动力传动系统匹配分析具有一定借鉴意义。

“一带一路”倡议对中国沿线区域入境旅游发展的政策效应评价

以2007—2019年中国31个省(区、市)面板数据,结合超效率及全局Malmquist指数与PSM-DID法实证检验“一带一路”倡议对入境旅游发展的政策效应。研究表明:①入境旅游的平均发展能力呈现为正增长,但产业空间格局差异仍未缓解,“一路”区域空间集聚明显,“一带”区域趋向空间极化发展;②倡议显著提高了沿线区域的入境旅游效率,但其实施效果具有滞后性,“一路”区域的政策响应优于“一带”;③倡议的政策效应具有区域异质性,经济发展水平与旅游交通条件对倡议的影响存在差异,结构红利与政策驱动效应显著,但旅游产业内核基础条件亟需提升,交通设施和资源要素优化应成为未来的提升关键。

Automatic Road Change Detection and GIS Updating from High Spatial Remotely-Sensed Imagery

This paper presents a framework for road network change detection in order to update the Canadian National Topographic DataBase (NTDB). The methodology has been developed on the basis of road extraction from IRS\|pan images (with a 5.8 m spatial resolution) by using a wavelet approach. The feature matching and conflation techniques are used to road change detection and updating. Elementary experiments have showed that the proposed framework could be used for developing an operational road database updating system.

基于内蒙古区域工况下的某6×4R重型商用车开发研究

文章结合内蒙古区域煤炭运输市场重型商用车的运输特点,开发某6×4R重型商用车。基于内蒙古区域重型半挂牵引车行车大数据,采用主成分分析法和马尔科夫概率预测法,构建出符合汽车行驶驱动力需求的内蒙古区域典型工况路谱,并在此基础上开展整车动力系统匹配设计,整车综合油耗降低1 L/100 km,实现最佳燃油经济性。同时,提出不同的防抱死制动系统(ABS)布置方案,并通过试验验证整车ABS法规符合性,进而确定ABS布置方案。文章提出的基于内蒙古工况下的整车动力系统匹配仿真方法,有助于设计出适合内蒙古地区的重型半挂牵引车的高效动力总成系统,其ABS布置方案,可应用于驱动桥带提升或随动功能的车型开发。

A novel vehicle navigation map matching algorithm based on fuzzy logic and its application

A new real-time map matching algorithm based on fuzzy logic is proposed. 3 main factors affecting the reliability of map matching, including the distance between the vehicle location and the matching road segment, the angle between the vehicle direction and the road segment direction and the road connectivity are discussed. Fuzzy rules for the distance, angle and connectivity are presented to calculate the matching reliability. 2 indicators for estimating the matching reliability are then derived, one is the lower limit of the reliability, and the other is the limit error of the difference between the maximal value and the second-maximal value of the reliability. A real-time map-matching system based on fuzzy logic is therefore developed. Using the real data of global positioning system(GIS) based navigation and geographic information system(GPS) based road map, the method is verified and the (results) prove the effectiveness of the proposed method.

基于路网密度的城市功能空间分布评价——以西安市为例

从路网密度视角开展城市功能空间分布评价,对提升城市活力、优化功能空间结构、实现城市可持续发展具有重要意义。以西安市为例,结合POI数据和道路网数据,采用双变量空间自相关方法开展路网密度与城市功能的空间耦合分析,将空间单元划分为适配空间和错配空间(包括拥挤空间和低效空间)两大类型,并针对错配空间提出结合路网密度的适宜性功能优化策略。研究发现,西安市路网密度与城市功能空间耦合度较高,呈“适配—错配—适配”环状分布格局,建议通过疏解置换和有机更新策略优化拥挤空间,通过功能混合与集聚提升策略优化低效空间,从而实现城市资源的集约高效利用。

无人驾驶汽车路面自适应MPC轨迹跟踪控制

针对无人驾驶汽车轨迹跟踪工况范围狭窄、评价方法片面和路面自适应控制不足等问题,研究全车速和全道路附着系数工况轨迹跟踪精度和行驶安全性.提出路面自适应的多约束模型预测控制,由车辆3自由度非线性动力学模型得到离散化线性时变预测模型,根据传感器检测的道路附着系数实现路面自适应的车速范围匹配,制定车速增量约束条件.融合CarSim和Matlab软件进行研究,得到路径跟踪误差、侧向加速度、质心侧偏角、前轮侧偏角最大值和标准差随车速和道路附着系数变化的规律;结合轮胎侧偏机理评价行驶安全性,划分全工况轨迹跟踪稳定区和失稳区.结果表明:根据道路附着系数自适应调节车速大小,汽车在全工况下,轨迹跟踪精度较高,行驶安全性较好.

基于自适应轨迹聚类的城市路网提取与更新方法

由于城市路网更新频繁及传统地图更新方法的局限性,很多城市路网地图数据无法及时更新。基于移动轨迹数据的路网地图更新是实现城市路网地图快速、高效更新的有效途径。虽然目前基于移动轨迹数据发展了一些基于栅格化的方法、基于聚类的方法和增量化的方法来提取与更新城市路网,但这些方法对于参数依赖性较强,且难以准确提取较为复杂的道路形状。因此,本文结合移动轨迹数据的特点及道路网的结构特征,提出了一种基于移动轨迹匹配的城市路网地图动态更新方法。首先,通过轨迹点的位置和方向属性进行轨迹点–路段匹配;然后,对未匹配的轨迹点采用顾及方向约束的空间自适应聚类算法进行聚类,并对每个聚类进行最优曲线拟合,获得新增道路;最后,以城市浮动车轨迹数据为例进行实验与对比分析。实验结果表明,与现有方法相比,本文方法需要的参数较少,且能够处理复杂形状道路的提取,具有较高的运行效率。

基于最小费用网络流的多指标道路网匹配方法

多源道路网匹配过程中存在次优化问题,依靠单一度量指标的匹配结果往往出现误匹配和漏匹配,为此,文中提出一种基于最小费用网络流的多指标综合路网匹配方法。该方法通过在关系数据库中构建最小费用网络流模型,综合距离相似度、方向相似度和形状相似度用于度量道路实体相似度,并考虑异源道路网M∶N匹配进行全局最优化匹配。实验选取6个实验区的OpenStreetMap路网和TIGER/Line路网进行综合验证。结果表明,该方法的匹配准确率相较单一指标有显著提升,并能有效解决次优化问题导致的误匹配和漏匹配。

基于图卷积神经网络的道路网匹配

针对当前道路网匹配方法中权重关系和匹配阈值的确定主观性强、容易产生匹配误差等问题,提出了一种结合图卷积神经网络的道路网匹配方法。首先,选取长度、方向、距离、拓扑4个相似性度量因子作为道路网匹配模型的特征因子;然后,将待匹配道路转化为以道路为节点、道路的连接关系为边的对偶图的图结构,即把道路网匹配问题转化为节点分类的问题;最后,通过搭建图卷积神经网络实现道路网的匹配。试验结果表明,与传统方法相比,该方法的匹配准确率、召回率及F值均得到大幅提升,能够有效解决道路网匹配问题。