智能环境监测系统在提升机无人值守中的应用

矿山智能化、无人化要求的提出,使配电室、控制室环境监测显得尤为重要。本文论述了基于配电室、控制室环境监测技术的软、硬件的设计与实现。智能环境监测系统以环境监测主机为硬件核心,以温湿度传感器、烟雾传感器为环境采集设备,以PC机为上位机监测系统,通过MODBUS TCPIP协议实现数据通讯,最终实现了通过上位机进行实时数据监测、历史数据查询、数据曲线查询、超限报警、报警提示等功能。此外,该系统能够与提升机电控系统进行闭锁,在环境异常时,系统停机,以保护设备和人员的安全。通过对智能环境监测系统进行详细的介绍,实现了提升机无人值守系统中对环境参数的实时监测和管理。     

铁路ZYJ7转辙机综合培训系统的研究与实现

针对轨道交通的转辙机控制电路故障检修训练难问题,文章设计了一款ZYJ7转辙机的智能综合实训平台,介绍了该实训平台的组成和工作原理,并论述了系统总体架构的设计方案,包括上位机和下位机故障设置设计方案。该实训平台能快速设置电路故障,模拟转辙机控制电路故障现场。学生根据故障现象进行检测,然后在上位机作答并提交答卷。经实践验证,该实训平台有效解决了转辙机的故障检修训练和考核评分问题,大大提高了实训效率。     

越南球也-宁平高速公路机电系统设计

球也-宁平高速公路是越南第一条具有完整机电系统的高速公路。文章主要介绍了越南球也-宁平高速公路收费、监控、通信系统的概况,分析了该系统与广西高速公路机电系统间的不同之处。     

一个体系,多种表述——交通安全应急通信发展的历史沿革

上个世纪五十年代,中国交通通信信息中心接管了原有的海岸电台。此后数十年,中国交通安全应急通信渐成体系。八十年代,中国交通通信信息中心在接管公路交通通信行业管理的同时,又以水上安全通信起家,逐步建设和完善了交通应急安全通信系统。几十年来,其先后完成了北京海事卫星地面站、全球海上遇险与安全系统(GMDSS)地面无线通信系统、交通卫星长途专用通信网,全球搜救卫星系统中国任务控制中心(MCC)、交通应急宽带VSAT系统、交通行业政务专网、远程船舶识别与跟踪系统(LRIT)数据中心、全国重点营运车辆联网联控系统等众多富有特色的交     

γ射线管道测垢厚系统计

针对清洗管道过程中测量内垢厚的问题,介绍利用γ射线透射法测量管道垢厚的系统设计。该系统可测量多种管道内垢层厚度,系统样机主要由γ射线收发模块、信号预处理模块、单片机控制模块、上位机管理通讯模块等组成。通过实验,样机可准确测量管道内垢层厚度,为管道的清洗与检测提供了科学依据。     

铁路通信系统中的信息安全隐患识别与防范策略

随着信息技术的不断发展,铁路通信系统已成为铁路运输中不可或缺的组成部分。然而,在铁路通信系统中,信息安全问题也日益严峻,面临着各种潜在的风险和威胁。基于此,对铁路通信系统中的信息安全问题进行分析,在此基础上,进一步分析铁路通信系统中存在的信息安全隐患,并结合铁路通信系统的特点,提出具有一定针对性的防范策略,以期更好地保护铁路通信系统的信息安全,为铁路通信系统的安全高效运行提供保障。     

高速公路通信系统的收费与监控应用解析

为了保障高速公路的通信安全,我国建立了高速公路信息通信系统,以便人们在使用公路的过程中进行收费与监控工作.本文以高速公路通信系统的建立为研究对象,着力于收费与监控两项内容,对这一系统如何应用于实践中进行分析与探讨.     

新时期高速公路机电通信系统新技术的应用

为了促进高速公路行业快速发展,首先,对机电通信系统搭建要点进行分析;其次,总结新技术应用规范;再次,研究高速公路机电通信系统新技术应用策略;最后,对未来高速公路机电通信系统发展趋势进行展望。旨在提升高速公路机电通信系统稳定性。     

地铁民用通信系统资源经营管理模式研究

地铁民用通信系统在满足乘客在地下空间的通信信息需求,为司机、设备维修人员及站务调度等人员提供必要替换通信手段方面,发挥着日益重要的作用。本文通过分析目前我国地铁民用通信系统投资建设、经营管理、维护改造等模式的关键影响因素,对地铁民用通信系统信息平台的统筹经营运作提供了参考借鉴及合理化建议。     

高速公路机电工程通信系统技术探究

高速公路机电工程主要涉及通信、监控以及收费系统,而要想保障其稳定运行,则应做好通信设施的布置。而今网络化和信息化等诸多先进技术已经得到了极为广泛的应用,进而为高速公路机电工程的高效配置提供了极为有利的条件。基于高速公路机电工程通信系统理论的论述探究其中所用技术的特点,以期能够对相关的系统配置提供一定的参考。     

Distributed surveillance on freeways emphasizing incident detection and verification

Efficient freeway management requires continuous decision-making based on conditions on the network and an understanding of the impacts of the decisions made. These conditions are usually measured with fixed-point surveillance systems, most of which are deployed in such a manner as to require communication links that are always connected and are polled at regular intervals. All of the sensor data are typically sent to a Traffic Management Center (TMC) for assessment, yet most of the time no action is taken in response to the data, leading to unnecessarily high communication costs.To reduce communication costs without a significant loss in the quality of information received at the TMC this paper lays the foundation for an event driven communication system by examining the sequence of events at the detector stations in the context of incident detection. Where, following the broadest convention on freeways, an incident is any non-recurring event that causes a temporary bottleneck and restricts flow. Although the focus is incident detection, the proposed communication system could easily support many other applications that use aggregate data, e.g., measuring average annual daily travel (AADT). The methodology is generalizable to most common freeway geometries and care is taken in the paper to specifically address the situation where an incident interacts with a recurring bottleneck.To address the normally high communications costs, a portion of the decision-making process is transferred from the TMC to the field controllers, which would make the initial evaluation of conditions and only send data that might elicit a control response or benefit comparative decisions between detector stations. In other words, rather than relying on the conventional, centrally polled communication system, these events could be used to initiate communication from the field when the potential value outweighs the cost per communication. The process could also lead to better data handling for decision-making or archiving in a conventional, polled communication system as well. We develop the methodology by deconstructing several incidents on a freeway and identify the observable events at a pair of detector stations that may be upstream, downstream or straddle the incident. This analytical process could be repeated for any other condition of interest.     

A new roadway lighting measurement system

Past studies have shown that the level of roadway lighting is an important factor for nighttime roadway safety. To evaluate roadway lighting systems and maintain their functionality, it is essential to perform field lighting measurements. Currently, field measurements of roadway lighting systems are often conducted by handheld light meters using a short sample section. The evaluation of an entire corridor or a longer section is difficult when using the traditional manual measurement methods. This paper addresses this difficulty by developing a new lighting measurement system that can be used to collect massive amounts of lighting level data in an efficient, safe, and effective manner. The system consists of a light meter, a distance measurement instrument (DMI), a computer, software, and an electronic converter circuit to connect the computer and other hardware. Software was developed for the communication link between the computer and the light meter, and to record both the distance and illuminance data. The system was calibrated and validated with the field data. The new system will not only reduce future data collection costs, but also improve safety for field data collection personnel. The system has been approved for use to collect illuminance data on Florida state roads greater than or equal to 250-miles in length.     

Perceptions of new electronic media for business communication

A model of communications media choice in business organizations is formulated based upon the results of exploratory interviews and the consumer choice literature. Choice is modelled as a function of organizational characteristics, individual characteristics, communication activity characteristics, communication initiator-recipient relationships and perceptions and feelings about available media. Hypotheses concerning media perceptions are developed from the exploratory interviews and tested using survey results from two firms in the Chicago region. The methodology developed in this research provides a useful approach to exploring preferences for and choices of communication media. As a paradigm for future research, it can be used to extend our understanding of communications media usage.     

Platoon based cooperative driving model with consideration of realistic inter-vehicle communication

Recent developments of information and communication technologies (ICT) have enabled vehicles to timely communicate with each other through wireless technologies, which will form future (intelligent) traffic systems (ITS) consisting of so-called connected vehicles. Cooperative driving with the connected vehicles is regarded as a promising driving pattern to significantly improve transportation efficiency and traffic safety. Nevertheless, unreliable vehicular communications also introduce packet loss and transmission delay when vehicular kinetic information or control commands are disseminated among vehicles, which brings more challenges in the system modeling and optimization. Currently, no data has been yet available for the calibration and validation of a model for ITS, and most research has been only conducted for a theoretical point of view. Along this line, this paper focuses on the (theoretical) development of a more general (microscopic) traffic model which enables the cooperative driving behavior via a so-called inter-vehicle communication (IVC). To this end, we design a consensus-based controller for the cooperative driving system (CDS) considering (intelligent) traffic flow that consists of many platoons moving together. More specifically, the IEEE 802.11p, the de facto vehicular networking standard required to support ITS applications, is selected as the IVC protocols of the CDS, in order to investigate how the vehicular communications affect the features of intelligent traffic flow. This study essentially explores the relationship between IVC and cooperative driving, which can be exploited as the reference for the CDS optimization and design.     

Enhanced cooperative car-following traffic model with the combination of V2V and V2I communication

Vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communication are emerging components of intelligent transport systems (ITS) based on which vehicles can drive in a cooperative way and, hence, significantly improve traffic flow efficiency. However, due to the high vehicle mobility, the unreliable vehicular communications such as packet loss and transmission delay can impair the performance of the cooperative driving system (CDS). In addition, the downstream traffic information collected by roadside sensors in the V2I communication may introduce measurement errors, which also affect the performance of the CDS. The goal of this paper is to bridge the gap between traffic flow modelling and communication approaches in order to build up better cooperative traffic systems. To this end, we aim to develop an enhanced cooperative microscopic (car-following) traffic model considering V2V and V2I communication (or V2X for short), and investigate how vehicular communications affect the vehicle cooperative driving, especially in traffic disturbance scenarios. For these purposes, we design a novel consensus-based vehicle control algorithm for the CDS, in which not only the local traffic flow stability is guaranteed, but also the shock waves are supposed to be smoothed. The IEEE 802.11p, the defacto vehicular networking standard, is selected as the communication protocols, and the roadside sensors are deployed to collect the average speed in the targeted area as the downstream traffic reference. Specifically, the imperfections of vehicular communication as well as the measured information noise are taken into account. Numerical results show the efficiency of the proposed scheme. This paper attempts to theoretically investigate the relationship between vehicular communications and cooperative driving, which is needed for the future deployment of both connected vehicles and infrastructure (i.e. V2X).     

Special issue on intelligent transportation systems,big data and intelligent technology

ABSTRACT

Based on the increasing demands of transportation development, the concept of an Intelligent Transportation System (ITS) has received increasing attention in both academic and industry arenas. It integrates information, communications, computers and other technologies, and applies them in the field of transportation to build an integrated system of people, roads and vehicles by utilizing advanced data communication technologies. It can establish a large, fully functioning, real-time, accurate and efficient transportation management system. Intelligent transportation systems shift the focus from road managers to road users. In order to achieve this purpose, intelligent transportation systems use advanced technology to provide drivers with convenient information to help reduce traffic congestion and to increase available road capacity. This special issue is dedicated to exploring the most recent advances in intelligent transportation systems and big data based on intelligent technology.     

Enhanced high data rate communication system using embedded cooperative radar for intelligent transports systems

In maritime and aeronautical transports, intelligent systems such as AIS² or ADS-B³ are used for simultaneous location and data exchange. However nowadays, in guided transports domain, no commercial system is able to ensure the both functionalities. In this paper, we present the achievement of an original sensor allowing both localization and data communication inside the same system. They tend to improve reliability, safety and security on rails or facilitate new exploitation modes inside guided transports networks. Our laboratories, INRETS⁴ and DOAE⁵, achieved a mock-up of the radar system called CODIBDT⁶ the sensor is based on the principle of cooperative radar using a transponder inside targets. It uses a numerical correlation receiver and has a broad band of about 100 MHz for high data flow communications. An original coding technique, called 2πM,⁷ has been defined and implemented, which allows high data flow communication multiplexed with the localization functionality and ensure a multi-users access. This paper focuses on presenting simulations and experimental results, obtained with the realized mock-up in railway environment, in order to evaluate the system performances in terms of data flow, Bit Error Rate, computing time and complexity. The performances of the 2πM coding technique is compared to others techniques called SSS2⁸ and CPM⁹.     

Vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communication in a heterogeneous wireless network – Performance evaluation

Connected Vehicle Technology (CVT) requires wireless data transmission between vehicles (V2V), and vehicle-to-infrastructure (V2I). Evaluating the performance of different network options for V2V and V2I communication that ensure optimal utilization of resources is a prerequisite when designing and developing robust wireless networks for CVT applications. Though dedicated short range communication (DSRC) has been considered as the primary communication option for CVT safety applications, the use of other wireless technologies (e.g., Wi-Fi, LTE, WiMAX) allow longer range communications and throughput requirements that could not be supported by DSRC alone. Further, the use of other wireless technology potentially reduces the need for costly DSRC infrastructure. In this research, the authors evaluated the performance of Het-Net consisting of Wi-Fi, DSRC and LTE technologies for V2V and V2I communications. An application layer handoff method was developed to enable Het-Net communication for two CVT applications: traffic data collection, and forward collision warning. The handoff method ensures the optimal utilization of available communication options (i.e., eliminate the need of using multiple communication options at the same time) and corresponding backhaul communication infrastructure depending on the connected vehicle application requirements. Field studies conducted in this research demonstrated that the use of Het-Net broadened the range and coverage of V2V and V2I communications. The use of the application layer handoff technique to maintain seamless connectivity for CVT applications was also successfully demonstrated and can be adopted in future Het-Net supported connected vehicle applications. A long handoff time was observed when the application switches from LTE to Wi-Fi. The delay is largely due to the time required to activate the 802.11 link and the time required for the vehicle to associate with the RSU (i.e., access point). Modifying the application to implement a soft handoff where a new network is seamlessly connected before breaking from the existing network can greatly reduce (or eliminate) the interruption of network service observed by the application. However, the use of a Het-Net did not compromise the performance of the traffic data collection application as this application does not require very low latency, unlike connected vehicle safety applications. Field tests revealed that the handoff between networks in Het-Net required several seconds (i.e., higher than 200 ms required for safety applications). Thus, Het-Net could not be used to support safety applications that require communication latency less than 200 ms. However, Het-Net could provide additional/supplementary connectivity for safety applications to warn vehicles upstream to take proactive actions to avoid problem locations. To validate and establish the findings from field tests that included a limited number of connected vehicles, ns-3 simulation experiments with a larger number of connected vehicles were conducted involving a DSRC and LTE Het-Net scenario. The latency and packet delivery error trend obtained from ns-3 simulation were found to be similar to the field experiment results.     

Millimeter-wave communicating-radars for enhanced vehicle-to-vehicle communications

To be effective, safety relevant applications based on wireless communications between vehicles need a minimum rate of vehicles equipped with communication devices. Although this minimum rate of vehicles could be relatively low, it is still difficult to obtain starting from a nonequipped vehicles situation. However, Long and short range radars are becoming very popular these days for cruise control, obstacle detection, parking assistance and pre-crash sensing. These radars are active sensors that produce significant radiofrequency power in wide allocated frequency bands. They also integrate a sensitive receiver. To accelerate the vehicle-to-vehicle communications penetration rate, this paper evaluates the possibility of enhancing vehicle-to-vehicle communications by using communicating-radars working at millimeter-wave. Current allocated frequencies for both vehicle-to-vehicle communication and radars are presented. Short-range and long-range radar radiofrequency parameters are analyzed to verify that existing automotive radar radio standards are consistent with communication. At grazing angles above the road, the characteristics of the communicating-radar propagation channel are theoretically and experimentally studied and compared to a more conventional 5.9 GHz channel. An analysis of Ultra Wide Band radio communication providing simultaneous access to vehicles in the same communication area is presented. Lastly, relevant architectures for communicating-radars are discussed.