清管器在花-格管线的应用

为了实现管道输油最优化运行,就必须对管道进行维护与内部清理.用清管器定期地进行清蜡维护就是一种有效方法.文中主要介绍了青海油田花土沟--格尔木输油管线(简称花--格管线)正在应用的皮碗式清管器,并对其到站时间进行简单的计算,对多次采集实际时间进行对比,验证了其计算方法的可行性.同时,对于清管器的破损原因、清管过程中遇到...     

基于GPS和GSM的清管器智能跟踪系统

为了在清管施工中实时跟踪清管器,设计一种基于GPS系统和GSM通信系统的智能清管器跟踪系统,系统包括发射机、中继器和监控系统。发射机搭载在清管器上持续发射电磁信号和静磁信号,中继器预先埋设在设定的跟踪点接收和转发通过信息;清管器通过跟踪点时,中继器接收发射机发出的信号,精确识别出清管器并将通过时间和跟踪点GPS位置信息通过GSM网络发送至监控系统;监控系统接收到信息后,在监控界面地图上实时显示通过位置和通过时间。清管器卡堵时,系统可及时在地图上指示卡堵区间和到达卡堵现场路径。现场应用表明:该系统实现了清管器智能跟踪,通过时间和通过位置记录精确,降低清管施工中安全风险,节约成本。     

管道清管器缓蚀剂预膜技术与应用

油气管道的内腐蚀是管道常见的破坏形式,涂抹缓蚀剂可以延缓管道的腐蚀。对利用清管器进行管道缓蚀剂预膜作业的工艺技术进行了总结和介绍,并提供了清管预膜所需的技术指标的计算方法。实践应用表明,利用清管器对管道进行缓蚀剂预膜具有成膜性好、操作简单、在役修复的优点,为管道防腐提供了一种便捷方法。     

清管器研究及应用现状

文中研究了清管器的内部结构和运行原理,对于清管器的种类和用途进行了介绍。目前应用比较广泛的智能清管器主要基于涡流检测技术、超声波检测技术以及漏磁检测技术。但是由于技术的复杂性,使得智能清管器的应用还具有局限性。     

基于金属磁记忆的智能清管器技术可行性研究

文中对基于金属磁记忆的智能清管器用于管道腐蚀检测的可行性进行探讨,介绍了金属磁记忆检测原理,以MSP430F149单片机为核心,采用HMC1021型磁阻传感器为探头,设计了漏磁场检测系统,对裸采和透过聚氨酯材料检测到的漏磁场法向分量HP(Y)的过零点以及最大梯度值进行了分析、计算.结果表明:透过一定厚度聚氨酯材料检测到的裂缝附近漏磁场法向分量HP(Y)的梯度值已不再突出,但微分值仍具有明显的特征.因此,基于金属磁记忆的智能清管器技术具有一定的可行性.     

长输管道变径清管器研究进展

普通清管器无法满足变径管道的清管要求,有必要对管道变径检测技术及设备进行研究。介绍了管道变径设备的国内外研究现状,指出国内外研究水平的差距,并对变径清管器的优点进行了总结,重点对变径清管器的设计重点进行了介绍,并预测对变径清管器的密封皮碗、探头、磁路等关键技术的研究将在今后很长的时间内成为管道变径清管器的技术攻关点。     

小口径管道内检测通过能力验证试验

为了对某273 mm口径成品油管道内检测项目所用的清管器、检测器通过能力进行验证,设计了试验管道及验证工艺。试验管道通过能力与实际管道一致。验证工艺通过压缩空气推动水,最终推动清管器或检测器在试验管道中行进。现场验证试验证实项目采用的清管器及内检测器通过能力满足要求。     

浅谈输油管道漏点的确定

根据大庆至铁岭“庆铁线”太阳升至新庙输油管道腐蚀点泄漏，介绍多种管道检漏方法，着重介绍应用清管器技术来确定运行中管道漏点，通过理论计算确定漏点的具体位置和时间，以减少管道腐蚀泄漏造成的经济损失。     

天然气管道清通压力模拟

为了能够合理分析和处理清管过程中的实际问题,提高清管能力,基于质量守恒定律和牛顿第二定律,将管道内气体流动与清管器运动耦合起来,得到天然气管道清通压力计算方程。以四阶龙格-库塔算法对方程进行离散计算,结果表明:模拟计算结果与清通压力实验结果十分吻合,清管器在经过弯管、三通等阻力件时,均会使清通压力发生急变,通过分析清通压力的变化特点,可预测清管器的运动位置及到达管道出口的时间。     

清管器应用技术的发展

介绍了清管器的分类,概述了清管器在输油、油田注水、输气等管线中的除垢应用以及在管线检测方面的具体应用情况,给出了清管器应用技术的发展趋势.     

Integrity of map-matching algorithms

Map-matching algorithms are used to integrate positioning data with digital road network data so that vehicles can be placed on a road map. However, due to error associated with both positioning and map data, there can be a high degree of uncertainty associated with the map-matched locations. A quality indicator representing the level of confidence (integrity) in map-matched locations is essential for some Intelligent Transport System applications and could provide a warning to the user and provide a means of fast recovery from a failure. The objective of this paper is to determine an empirical method to derive the integrity of a map-matched location for three previously developed algorithms. This is achieved by formulating a metric based on various error sources associated with the positioning data and the map data. The metric ranges from 0 to 100 where 0 indicates a very high level of uncertainty in the map-matched location and 100 indicates a very low level of uncertainty. The integrity method is then tested for the three map-matching algorithms in the cases when the positioning data is from either a stand-alone global positioning system (GPS) or GPS integrated with deduced reckoning (DR) and for map data from three different scales (1:1250, 1:2500, and 1:50 000). The results suggest that the performance of the integrity method depends on the type of map-matching algorithm and the quality of the digital map data. A valid integrity warning is achieved 98.2% of the time in the case of the fuzzy logic map-matching algorithm with positioning data come from integrated GPS/DR and a digital map data with a scale of 1:2500.     

Location selection of city logistics centers under sustainability

City Logistics Centers (CLC) are an important part of the modern urban logistics system, and the selection of the location of a CLC has become a key problem in logistics and supply chain management. Integrating the economic, environmental, and social dimensions of sustainable development, this paper presents a new evaluation system for the location selection of a CLC from a sustainability perspective. A fuzzy multi-attribute group decision making (FMAGDM) technique based on a linguistic 2-tuple is used to evaluate potential alternative CLC locations. In this method, the linguistic evaluation values of all the evaluation criteria are transformed into linguistic 2-tuples. A new 2-tuple hybrid ordered weighted averaging (THOWA) operator is presented to aggregate the overall evaluation values of all experts into a collective evaluation value for each alternative, which is then used to rank and select alternative CLC locations. An application example is provided to validate the method developed and to highlight the implementation, practicality, and effectiveness by comparing with the fuzzy Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method.     

利用加速度计实现管道缺陷定位的研究

介绍了一种利用高分辩率加速度计实现管道缺陷定位的方法,通过加速度值对时间进行二次积分运算并进行适当的误差修正,可以得到智能清管器行走的精确距离,依据时标与距离的线性关系,达到较高的缺陷定位精度.室内实验研究表明,定位精度可以达到定标长度的0.2%.     

成品油管道泄漏监测与定位系统的研制

研制一套有效的成品油管道泄漏监测与定位系统,对于输油管道的安全运行及环境保护,减少企业经济损失具有重要的意义。根据现场实际工况,提出一种与SCADA系统相结合的成品油管道泄漏监测与定位系统方案,给出了系统的组成与工作原理。基于GPS授时与中断技术的异地同步采集保证了异地数据采集设备的精确同步。系统使用基于负压波的分段斜率法准确判断泄漏;采用小波变换精确检测负压波传到首末站的时间差,并给出了小波基函数的选取原则及定位方法。实际应用表明：系统报警响应时间短、误报率低、泄漏定位精度高。     

三维相对坐标测量法在大跨径拱桥中的应用

太平湖特大桥施工采用三维相对坐标测量法及提篮式拱桥计算程序,使用该方法能够准确、直观、快速地进行拱肋动态实时放样定位计算。文章结合工程实例,介绍了太平湖特大桥拱肋定位放样程序的编制和定位实际操作过程,为类似工程测量放样提供参考。     

燃气管道泄漏检测与定位技术研究

文中介绍了基于SCADA系统的燃气管道泄漏检测和定位技术,简述了压力梯度法、负压波法、瞬态模型法这3种常用的管道检测技术,给出数学模型,提出对压力梯度法与负压波数学公式的改进。根据压力梯度法的实验原理,在管道首末端各设置2个压力传感器,提高了检测精度;对负压波数学公式进行变形,使其更易求解。分析结果表明:随着对检测精度和定位精度要求的提高,多种技术方法综合运用应受到更多的关注和研究。     

清管器在输油管道中的运动规律研究

在分析清管物理模型的基础上,建立了清管器前段塞流动的特征参数计算模型、动态数学模型以及相应的数值计算方法,并进行了数值模拟。利用数学模拟方法可以计算清管过程中管线的压力分布,利用压力分布可以跟踪清管球在管线内的运行,这为混输管路的运行管理提供了理论依据。     

Vehicle Positioning for Improving Road Safety

Abstract

Vehicle positioning is a key requirement for many safety applications. Active safety systems require precise vehicle positioning in order to assess the safety threats accurately, especially for those systems which are developed for warning/intervention in safety critical situations. When warning drivers of a local hazard (e.g. an accident site), accurate vehicle location information is important for warning the right driver groups at the right time. Global positioning system and digital maps have become major tools for vehicle positioning providing not only vehicle location information but also geometry preview of the road being used. Advances in wireless communication have made it possible for a vehicle to share its location information with other vehicles and traffic operation centres which greatly increases the opportunities to apply vehicle positioning technologies for improving road safety. This paper presents a state‐of‐the‐art review of vehicle positioning requirements for safety applications and vehicle positioning technologies. The paper also examines key issues relating to current and potential future applications of vehicle positioning technologies for improving road safety.