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Timed RAISE方法在列控系统等级转换场景中的应用研究 总被引:1,自引:1,他引:0
《铁道标准设计通讯》2015,(8):164-169
高速铁路列车运行控制系统是一个复杂的实时性系统,结合其实际特点,将域方法作为系统描述的切入。通过对模型检验和定理证明两种验证方法的分析比较,提出使用基于定理证明的时间化工业软件工程的严格方法Timed RAISE形式化方法对等级转换(CTCS-2级至CTCS-3级)场景进行描述,并对其场景交互一致性和实时性进行验证,结果表明该场景不会出现场景交互一致性错误,也不会违反时间的约束。 相似文献
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Ice bending is a major failure mechanism of level ice when ships and marine structures interact with level ice. This paper aims to investigate the ice bending and ice load when level ice collides on ships and marine structures using numerical simulation method, and compare the numerical results with field test. The fracture of ice is simulated with extended finite element method (XFEM), and cohesive zone concept is used to describe the crack propagation. In order to consider the characteristics of S2 columnar ice, a transversely isotropic elastic material model is used for the ice bulk elements, and a transversely isotropic Tsai-Wu failure criterion is adopted to predict the initiation of cracks. A well-controlled field test of a landing craft bow colliding with level ice in Baltic Sea is simulated to verify the numerical scheme. The ice plate's continuous deformation, crack initiation and crack propagation at different impact velocities and angles are simulated and the results are discussed. In the simulation, the bending crack emerges at the midline of the top surface of ice plate, then propagates towards free boundary, and finally a circumferential crack forms. It is found that with the impact velocity increases, the bending load increases and the fracture size (perpendicular distance from the crack to the contact edge) decreases. And as the angle between the landing craft bow and vertical direction increases, the bending load and the fracture size decrease. The simulated results corresponds well with the field test. The competition between the circumferential crack and radial crack is also found in the simulation and will be discussed in this paper. The results show that this method well simulates the bending of level ice and predict the ice load, and provides a good approach for investigating the mechanism of different forms of level ice fracture. 相似文献
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对一类奇阶上三角矩阵的特征值反问题进行研究,通过两个给定特征对(λ,x),(μ,y)对矩阵的存在性及唯一性的条件进行讨论,在满足条件的前提下进行求解并给出表达式,通过数值例子验证算法的可行性. 相似文献
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A potential solution to reduce greenhouse gas (GHG) emissions in the transport sector is the use of alternative fuel vehicles (AFV). As global GHG emission standards have been in place for passenger cars for several years, infrastructure modelling for new AFV is an established topic. However, as the regulatory focus shifts towards heavy-duty vehicles (HDV), the market diffusion of AFV-HDV will increase as will planning the relevant AFV infrastructure for HDV. Existing modelling approaches need to be adapted, because the energy demand per individual refill increases significantly for HDV and there are regulatory as well as technical limitations for alternative fuel station (AFS) capacities at the same time. While the current research takes capacity restrictions for single stations into account, capacity limits for locations (i.e. nodes) – the places where refuelling stations are built such as highway entries, exits or intersections – are not yet considered. We extend existing models in this respect and introduce an optimal development for AFS considering (station) location capacity restrictions. The proposed method is applied to a case study of a potential fuel cell heavy-duty vehicle AFS network. We find that the location capacity limit has a major impact on the number of stations required, station utilization and station portfolio variety. 相似文献
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通过拥挤收费来缓解中心城市交通拥挤,是交通管理者探讨的一个热点,也出现了一些成功实施的案例。针对目前ERP系统的不足,本文利用ITS先进技术将拥挤收费与交通信息平台相结合,提出一个基于GPS技术的实时拥挤收费系统,描述了系统的工作流程与基本功能,并且建立起多车型多准则弹性需求下的拥挤收费费率优化双层规划模型。 相似文献
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基于MSC与UPPAAL的列控系统等级转换场景形式化验证 总被引:3,自引:3,他引:0
等级转换是C3级列控系统的重要场景,是列控系统兼容性的集中体现,转换的成功与否直接关系到列车的运行安全和行车效率。因此,有必要对设计规范中所描述的转换过程进行形式化建模和验证,以保障系统的安全性和实时性。为保证设计规范与所建模型的一致性,采取消息顺序图(MSC)与时间自动机相结合的方式,建立等级转换场景中C2级向C3级转换过程的MSC模型,并将其转换为时间自动机模型。应用UPPAAL对模型的安全性和受限活性进行仿真验证,结果表明设计规范中所描述的转换过程是安全可靠的,可以满足C3级列控系统的兼容性和安全性要求。 相似文献