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401.
京津城际客运专线线路设计主要技术条件的探讨 总被引:4,自引:4,他引:0
卢茂胜 《铁道标准设计通讯》2003,(12):15-17
针对京津城际客运专线的特点 ,参考国内外资料 ,提出对线路平面和纵断面设计主要技术条件的见解 相似文献
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Gaspar L. Gil Gómez Alexander Lönnergård Mohit H. Asher Mikael Nybacka Egbert Bakker Lars Drugge 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2017,55(7):945-969
Objective testing of vehicle handling in winter conditions has not been implemented yet because of its low repeatability and its low signal-to-noise ratio. Enabling this testing, by identifying robust manoeuvres and metrics, was the aim of this study. This has been achieved by using both experimental data, gathered with steering-robot tests on ice, and simulation models of different complexities. Simple bicycle models with brush and MF-tyre models were built, both optimally parameterised against the experimental data. The brush model presented a better balance in complexity performance. This model was also implemented in a Kalman filter to reduce measurement noise; however, a simpler low-pass filter showed almost similar results at lower cost. A more advanced full vehicle model was built in VI-CarRealTime, based on kinematics and compliance data, damper measurements, and real tyre measurements in winter conditions. This model offered better results and was therefore chosen to optimise the initial manoeuvres through test design and simulations. A sensitivity analysis (ANOVA) of the experimental data allowed one to classify the robustness of the metrics. Finally, to validate the results, the proposed and the initial manoeuvres were tested back to back in a new winter campaign. 相似文献
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A numerical approach was developed to analyze the transient behavior of towed cable during ac- tively controlled deployment/retrieval (DR). The cable motion is described by the lumped parameter method, its corresponding boundary conditions are presented. In view of its varying length during DR, two auxiliary arguments are introduced to describe its continuous varying length and discrete number of nodes(equations), the length is determined by the pay out(or reel-in) rate, which is then used to determine the node number by a logic relation. For the discrete mathematical model of towed cable, an algorithm was developed to deal with the discrete governing equations. The simulation results indicate that the cable experiences more com- plex motions due to its varying length, and tension fluctuates seriously in the startup and ending stage of deployment/retrieval. The effect of towing ship's motion in waves on cable during deployment/retrieval is also considered via numerical simulation. 相似文献
406.
制定工程机械的油耗定额势在必行.实践证明,采用对各种工程机械的基本燃油耗量进行修正的方法计算其油耗定额,切合实际,科学可靠. 相似文献
407.
避险车道设置的必要性一直是国内外学界关注的重点,但是目前却没有成型的理论推出。引进了加拿大和约旦科学家的理论,并且做了相应的改进,提出了新的三个列表:刹车毂温度列表,车速列表,建设条件列表。在三个列表的基础上,加入了权函数的概念。在权函数的设置中,我们充分考虑了三个因素的权重,从而得到了更精确的评价设置必要性。最后,我们在青海湖附近的一个长下坡路段应用了这一理论,得到了比较满意的结果。 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(11):1443-1469
In modern railway automatic train protection and automatic train control systems, odometry is a safety relevant on-board subsystem which estimates the instantaneous speed and the travelled distance of the train; a high reliability of the odometry estimate is fundamental, since an error on the train position may lead to a potentially dangerous overestimation of the distance available for braking. To improve the odometry estimate accuracy, data fusion of different inputs coming from a redundant sensor layout may be used. The aim of this work has been developing an innovative localisation algorithm for railway vehicles able to enhance the performances, in terms of speed and position estimation accuracy, of the classical odometry algorithms, such as the Italian Sistema Controllo Marcia Treno (SCMT). The proposed strategy consists of a sensor fusion between the information coming from a tachometer and an Inertial Measurements Unit (IMU). The sensor outputs have been simulated through a 3D multibody model of a railway vehicle. The work has provided the development of a custom IMU, designed by ECM S.p.a, in order to meet their industrial and business requirements. The industrial requirements have to be compliant with the European Train Control System (ETCS) standards: the European Rail Traffic Management System (ERTMS), a project developed by the European Union to improve the interoperability among different countries, in particular as regards the train control and command systems, fixes some standard values for the odometric (ODO) performance, in terms of speed and travelled distance estimation. The reliability of the ODO estimation has to be taken into account basing on the allowed speed profiles. The results of the currently used ODO algorithms can be improved, especially in case of degraded adhesion conditions; it has been verified in the simulation environment that the results of the proposed localisation algorithm are always compliant with the ERTMS requirements. The estimation strategy has good performance also under degraded adhesion conditions and could be put on board of high-speed railway vehicles; it represents an accurate and reliable solution. The IMU board is tested via a dedicated Hardware in the Loop (HIL) test rig: it includes an industrial robot able to replicate the motion of the railway vehicle. Through the generated experimental outputs the performances of the innovative localisation algorithm have been evaluated: the HIL test rig permitted to test the proposed algorithm, avoiding expensive (in terms of time and cost) on-track tests, obtaining encouraging results. In fact, the preliminary results show a significant improvement of the position and speed estimation performances compared to those obtained with SCMT algorithms, currently in use on the Italian railway network. 相似文献
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