快速控制原型技术的发展现状

阐述了快速控制原型技术的基本概念,介绍了当前的发展现状及快速控制原型仿真的几种实现方式.快速控制原型技术利用虚拟的控制器来控制真实的对象,可以快速地验证设计方案,缩短产品开发周期并降低开发费用.     

电化区段轨道电路迂回回路原因分析及整治方案

针对神朔线轨道迂回电路整治工程,分析与研究引起电化区段轨道电路迂回回路的原因,提出相应的解决方案。     

一种市域铁路引入城际铁路的电力设计

市域铁路引入城际铁路工程难点多、外电源及用电负荷情况复杂,现行规范标准尚不适应电力设计需求。结合某项目充分研究市域铁路接驳工程特点,提出铁路贯通线与双环网电力线路组合的电力供电方案。解决了市域铁路引入城际铁路并接驳市内轨道交通的电力设计问题,实现了集约化电力资源共享和运营管理网络化,符合交通一体化的国家发展战略,且对类似工程电力设计有重要的指导意义。     

高速动车组项目供应商的管理

分析总结高速动车组配件供应商的实际情况和主机厂对供应商管理的薄弱环节,借鉴欧洲先进的管理经验,提出打造高速动车组稳定供应链,重点围绕"融合性、合理性、平衡性"来提升管理理念、优化管理方法,实现"引进和优化欧洲先进供应商管理模式,解决动车组质量控制瓶颈问题,打造稳定供应链"的目的。     

New applications of EXIT chart for iterative decoding systems

Applications on iterative control and multiple input multiple output （MIMO） system were developed. Two new charts derived from extrinsic information transfer （EXIT） chart were employed as the designing tools, which are called as output mutual information chart with defined iterative degree （DID） chart and near optimum output mutual information （NOMI） chart respectively. Different from the EXIT chart, they can show the iterative performance on the whole signal-to-noise ratio range with one single curve, whereas computation complexity is greatly reduced compared with conventional bit error ratio （BER） performance curve. The iterative control was implemented according to a near-optimum iterative degree vector determined by NOMI chart, the reasonability of uncertain parameters was analyzed in one MIMO system. The concepts were illustrated based on bit-interleaved coded modulation with iterative decoding （BICM-ID）.     

一种电气化铁路低压电力电子电源装置研究

铁路电力设计规范规定,通信设备、信号设备、信息设备等一级负荷需要由两路相互独立的电源供电。为解决我国西部电网薄弱地区铁路沿线上述用电负荷供电可靠性问题,提出一种电气化铁路低压电力电子电源装置。针对接入需求,详细描述该低压电源的拓扑结构和工作原理。同时,为适应输入侧电压波动问题,提出双闭环整流控制策略和输出电压控制策略。考虑到实际应用的多种方式,提出固定式安装和移动车载式安装的新思路,以适应不同场合下的应用需求。之后利用PSIM仿真软件搭建详细的仿真模型,通过仿真结果证明了本电源拓扑、原理、控制的可行性。最后,在实验室搭建了所述电源的实验室样机,利用实验证明了低压电力电子电源具有良好的可实现性。     

Improved vehicle classification from dual-loop detectors in congested traffic

Vehicle classification is an important traffic parameter for transportation planning and infrastructure management. Length-based vehicle classification from dual loop detectors is among the lowest cost technologies commonly used for collecting these data. Like many vehicle classification technologies, the dual loop approach works well in free flow traffic. Effective vehicle lengths are measured from the quotient of the detector dwell time and vehicle traversal time between the paired loops. This approach implicitly assumes that vehicle acceleration is negligible, but unfortunately at low speeds this assumption is invalid and length-based classification performance degrades in congestion.To addresses this problem, we seek a solution that relies strictly on the measured effective vehicle length and measured speed. We analytically evaluate the feasible range of true effective vehicle lengths that could underlie a given combination of measured effective vehicle length, measured speed, and unobserved acceleration at a dual loop detector. From this analysis we find that there are small uncertainty zones where the measured length class can differ from the true length class, depending on the unobserved acceleration. In other words, a given combination of measured speed and measured effective vehicle length falling in the uncertainty zones could arise from vehicles with different true length classes. Outside of the uncertainty zones, any error in the measured effective vehicle length due to acceleration will not lead to an error in the measured length class. Thus, by mapping these uncertainty zones, most vehicles can be accurately sorted to a single length class, while the few vehicles that fall within the uncertainty zones are assigned to two or more classes. We find that these uncertainty zones remain small down to about 10 mph and then grow exponentially as speeds drop further.Using empirical data from stop-and-go traffic at a well-tuned loop detector station the best conventional approach does surprisingly well; however, our new approach does even better, reducing the classification error rate due to acceleration by at least a factor of four relative to the best conventional method. Meanwhile, our approach still assigns over 98% of the vehicles to a single class.     

An extended generalized filter algorithm for urban expressway traffic time estimation based on heterogeneous data

Travel time estimation and its variation for urban expressways are vital to both the information provision to road users, and the system evaluation and management for traffic administrators. Fruitful research efforts have been made to develop methodologies of reconstructing spatiotemporal traffic states mainly for freeways based on one or multiple data sources. However, few studies specifically focused on urban expressways. There are more intensive merging and diverging traffic due to short distances between ramps, for example, 300–500 m. Based on the empirical analysis of traffic data collected on a typical segment of a congested urban expressway, this study proposes an extended generalized filter algorithm for the urban expressway traffic state estimation based on heterogeneous data. More specifically, the multiple sources of data include both fixed sensor data (e.g., inductive loops or radar data) and global positioning system (GPS) probe vehicle data. This study compares the proposed algorithm and the traditional algorithm for freeways using data collected on the segment of expressway in Beijing, China. Results demonstrate the advantage of the proposed method, as well as its feasibility and effectiveness.     

A railway vehicle multibody model for real-time applications

Hardware in the loop (HIL) techniques are widely used for fast prototyping of control systems, electronic and mechatronic devices. In the railway field, several mechatronic on board subsystems are often tested and calibrated following the HIL approach. The accuracy of HIL tests depends on how the simulated virtual environment approximates the physical conditions. As the computational power available on real-time hardware grows, the demand for more complex and realistic models of railway vehicles for real-time application increases. In past research activities, the authors worked on the implementation of simplified real-time models for several applications and in particular for an HIL test rig devoted to the type approval of wheel slide protection systems. The activity has then been focused on the development of a three-dimensional model of the dynamics of a railway vehicle for more complex applications. The paper summarises the features and the results of the study.     

稳定控制回路振铃现象的消除及其关键参数的选择

该文针对导弹稳定控制回路对象讨论Dahlin控制器设计问题。在复频域分析的基础上探讨了二阶对象期望闭环传递函数的合理形式。通过对期望闭环传递函数和控制对象的分析找到了导致二阶对象Dahlin控制器产生振铃的原因,给出了判定振铃产生的条件,并且提出了修正设计方法以及解决振铃现象中关键参数选择的问题。