轨道交通广播音量实时自动调节方案设计

轨道交通列车运行噪声幅度随运行情况变化很大,现有的轨道交通广播系统的广播音量不能跟随噪声的变化实时调整,影响到乘客听取广播信息.对此,提出一种可以有效解决该问题的技术方案.     

基于ZigBee无线通信的车厢无线烟雾预警系统设计与实现

当前普遍采用的传统车厢烟雾浓度报警系统无法针对复杂条件和多变环境下的烟雾浓度信息进行准确采集和特征表达,导致报警系统精确度无法保证。针对复杂环境信息准确描述烟雾内部特征,在语义网络调节的基础上设计一种列车车厢烟雾无线检测预警系统,可以从根本上满足实践条件下弥补传统车厢烟雾浓度报警的不足。系统以ARMS2C2440为核心控制器,采用ZigBee无线通信模块与语义网络结合的方式调节语义网络距离描述表征烟雾浓度的相关特征信息阈值,通过语义网络节点进行数据传递和交换,进行比较报警,提高系统的准确度和及时性。     

上海轨道交通TETRA系统列车调度指挥切换研究

文章介绍了上海轨道交通列车调度指挥子系统,分析了运营人员无线调度通信过程的要求及列车调度区域转换实现方法。在研究上海轨道交通列车调度区切换现状和存在的问题、运营单位对应需求的基础上,提出了三种调度区切换方案,经分析比较,推荐了ATS实时提供列车信息、人工确认调度区转换的方案。     

浅谈轨道交通信号系统设计与运输管理

本文阐述了轨道交通的概念,详细分析了轨道信号系统设计的有关内容,并基于此基础之上从多个层面叙述了轨道交通运输管理的多种功能,期望以此能加强人们对轨道交通信号系统工程的了解和建设,促使其更加科学有序地运作.     

上海轨道交通350兆公安数字集群TETRA覆盖系统解决方案初探

文章主要通过对轨道交通350兆公安数字集群TETRA覆盖系统组网方案的分析比较,提出了优化的"中区制基站+备用无线链路"解决方案,该方案具有增强多级故障弱化功能,可实现更好的性价比。     

软件功能测试管理模型在上海轨道交通AFC系统中的应用

上海轨道交通的线路数逐年递增,随之自动售检票系统的规模越来越大,如何管理由于自动售检票系统的应用软件版本不断升级带来的软件功能测试的管理问题亟待解决本文借鉴ITIL思想,提出一个针对软件功能测试的管理模型应用表明,该模型在上海轨道交通自动售检票系统的测试管理中是成功和有效的     

轨道交通通信传输技术的分析与比较

轨道交通通信中,传输技术具有十分重要的作用,有利于保证通信的正常进行,提升轨道列车运行的安全性.本文在介绍轨道交通通信传输技术类型的基础上,对其进行分析与比较,旨在为实际选择使用提供合理的参考.     

基于轨道交通无线环境图的大规模天线信道估计技术研究

随着移动通信技术的不断发展,为轨道交通监控以及旅客提供高速宽带服务的无线通信成为了目前移动通信研究的热点,高速宽带无线通信面临着高可靠性、强环境适应性、低复杂度等诸多挑战。本文对大规模天线系统中的信道估计过程进行推导,研究了基于轨道交通无线环境图的信道估计优化方案,研究表明该方案能够显著降低大规模天线系统信道估计的计算复杂度。     

基于轨道交通的资产管理系统设计与实现

为了支持与推进兰州市轨道交通有限公司数字化转型、智能化发展,进一步提高城市轨道交通设施设备的管理精度和管理效率,以及实现城市轨道交通设施设备管理的信息化、规范化和标准化,在借鉴国内轨道交通企业管理和数字化信息化实践先进经验和分析兰州市轨道交通有限公司信息化战略和业务需求的基础上,调研轨道公司需求,编写编码规范并设计适合兰州的轨道交通资产管理系统,实现轨道交通资产的全生命周期管理。     

轨道交通通信传输技术的分析与比较

本文通过现有的轨道交通通信传输技术进行分析,提出针对性建议,有效提高轨道交通通讯传输的高效性和准确性,确保轨道交通通信系统安全稳定运行,促进轨道交通通信传输技术的快速发展,希望能够给相关人员提供参考.     

Real-time estimation of intrinsic and reflex stiffness

Joint stiffness defines the dynamic relationship between the position of the joint and the torque acting about it. Joint stiffness is composed of two components: intrinsic and reflex stiffness. Separating the two stiffness components is difficult because they appear and change together. A number of approaches have been used to distinguish the components, but all these are inherently off-line. We have developed a novel algorithm that estimates the two components of ankle stiffness in real time. Cross-correlations between torque and position, velocity, and acceleration are used to estimate intrinsic stiffness. The reflex torque is then estimated by subtracting the estimated intrinsic components and the reflex stiffness estimated by computing the impulse response function (IRF) between the estimated reflex torque and the half-wave rectified velocity. A novel position perturbation, consisting of pseudo-random pulses of different lengths, is used to eliminate covariance between intrinsic and reflex stiffness estimates. Simulation results showed that the algorithm estimates intrinsic and reflex stiffness very accurately and responds to changes in stiffness in less than 15 s. Validation with experimental data showed that the real-time estimates were in close agreement with the estimates generated by an established off-line intrinsic and reflex stiffness identification algorithm.     

基于K-means的上海地铁站点分级研究

科学合理的地铁站点分级体系能够为车站资源分配及管理模式的选择提供决策依据.通过运用图论知识,结合Space L法构建了上海市地铁全网的拓扑模型.并选取图论中度,接近中心性和介数的3个重要度指标,结合各站的客流量分级指标及城市中心站点对各站点的辐射影响指标,运用K-means聚类算法,建立了涵盖多指标多因素的站点分级体系.     

Real-time estimation of the parameters of long-range dependence

An on-line version of the Abry-Veitch (see IEEE GLOBECOM'98, Sydney, Australia,p.3716-21, 1998) wavelet-based estimator of the Hurst parameter is presented. It has very low memory and computational requirements and scales naturally to arbitrarily high data rates, enabling its use in real-time applications such as admission control, and avoiding the need to store huge data sets for off-line analysis. The performance of the estimator as a function of the length of data processed is demonstrated using simulated data. An implementation for 10-Mb/s Ethernet based on standard hardware supporting sampling rates of 1 data point per millisecond is described, and results of its operation presented, as is an implementation for 155-Mb/s asynchronous transfer mode networks. Finally we illustrate the power of on-line measurements by collecting measurements over a period of five months, and using them to look for diurnal trends in scaling properties of the data     

实时ADI仿真下感应电机全阶观测器的研究

针对当前无速度传感器的控制方法中,存在低频时无法稳定运行、转速估算不精准、计算量偏大等问题,利用鲁棒性控制理论、线性矩阵不等式(LMI)来选择观测器的增益,推导了符合稳定性与收敛性要求的自适应律。并在此基础上,优化设计了转子速度和定子电阻能同时观测的自适应全阶磁链观测器,以此来对转子速度进行准确估算,确保电机在全速范围内稳定运行。用MATLAB对自适应全阶磁链观测器进行模型仿真,最后以实时ADI半实物仿真试验系统验证了在实际运用中自适应全阶磁链观测器的设计在全速范围内准确估算转速的可行性,且有良好的抗负载扰动能力。     

Real-time slip-based estimation of maximum tire-road friction coefficient

This paper presents a real-time maximum tire-road friction coefficient estimation method and field test results. The estimator is based on the relationship between the wheel slip ratio and the friction coefficient. An effective tire radius observer and a tire normal force observer have been designed for the computation of the slip ratio from wheel speed and vehicle speed measurements. The effective tire radius observer has been used so that the proposed method works for all driving situations. A tractive force estimator, a brake gain estimator, and a normal force observer have been used for the estimation of the friction coefficient. The proposed estimation method for the maximum tire-road friction coefficient has been implemented using a fifth wheel and typical vehicle sensors such as engine speed, carrier speed, throttle position, and brake pressure sensors.     

Real-time road surface and semantic lane estimation using deep features

In this article, we present a robust real-time road surface and semantic lane marker estimation algorithm using the deconvolution neural network and extra trees-based decision forest. Our proposed algorithm simultaneously performs three environment perception tasks on colour and depth images, even under challenging conditions, namely road surface estimation, lane marker localization, and lane marker semantic information estimation. The lane marker semantic information implies the lane marker type such as dotted lane marker or continuous lane marker. The task of road surface estimation is performed with a trained deconvolution neural network. For the lane marker localization task, a scene-based extra trees regression framework is used to localize the lane markers in the given road. To account for the variations in the number and characteristics of the lane markers in the road scene, multiple regression models indexed with scene labels are used. The pre-defined scene labels correspond to the lane marker variations in a given scene, and an extra trees-based classification model is trained to estimate them from the road features. The road features, given as an input to the extra trees frameworks, are extracted from the road image using the trained filters of the deconvolution network. The proposed algorithm is validated using multiple acquired datasets. A comparative analysis is also conducted with baseline algorithms, and an improved accuracy is reported. Moreover, a detailed parameter evaluation is also performed. We report a computational time of 90 ms per frame.     

Real-time frequency and 2-D angle estimation with sub-Nyquistspatio-temporal sampling

An algorithm is presented for real-time estimation of the frequency and azimuth and elevation angles of each signal incident on an airborne antenna array system over a very wide frequency band (2-18 GHz) commensurate with electronic signal warfare. The algorithm provides unambiguous frequency estimation despite severe temporal undersampling necessitated by cost/complexity of hardware considerations. The 2-18 GHz spectrum is decomposed into 1-GHz bands. The baseband output of each antenna is sent through two 250-MHz sampled channels where one is delayed relative to the other (prior to sampling) by 0.5 ns, which is the Nyquist interval for a 1-GHz bandwidth. Due to the high variance of the Direct ESPRIT frequency estimator, aliased frequencies are estimated via a simple formula and translated to the proper aliasing zone, utilizing eigenvector information generated by PRO-ESPRIT. The algorithm also provides unambigous 2-D angle estimate over the entire 2-18 GHz bandwidth, despite severe spatial undersampling at the higher end of this band necessitated by mutual coupling considerations and resolving power requirements at the lower end of the band. Eigenvector information generated by PRO-ESPRTT is used to facilitate computationally simple estimation of azimuth and elevation angles that are automatically paired with corresponding frequency estimates despite aliasing. Simulations are presented demonstrating the capabilities of the algorithm     

Bayesian estimation of reliability function and hazard rate

The Bayes estimates of reliability function and hazard rate function of the finite range failure model have been developed based on life tests that are terminated at a preassigned time point or after a certain number of failures have occurred, taking the order of observations into consideration. For the prior distribution of the parameter involved, the uniform, exponential and inverted gamma densities have been considered. As an example, failure data for a V600 indicator tube used in aircraft radar sets, which fit well the finite range failure model, have been considered as the current distribution for obtaining the Bayes estimates of the reliability function.     

Accurate full wave estimation of quality factor and resonancefrequency of HTS microstrip resonator

The spectral domain technique is employed to estimate characteristics of a high temperature superconducting (HTS) microstripline resonator taking into account most of the practical operating conditions to provide accurate representation of device performance. This analysis is expected to be quite useful in CAD of high Q resonators and sharp cutoff filters used in microwave communications     

高性能全搜索可变块运动估计的VLSI设计

给出了一种用于H.264全搜索可变块匹配算法的运动估计电路的改进结构,并完成了VLSI设计的仿真验证.在传统脉动阵列,全流水线设计的基础上,通过引入片内Cache,增加输入端口,大大减少传统方式下对延迟寄存器的依赖,进一步降低了功耗.仿真实验以CIF图像(352×288)为例进行结构验证,证明设计能实时处理H.264格式标准下的视频序列.