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The Traffic Alert and Collision Avoidance System (TCAS) is a world-wide accepted last-resort means of reducing the probability and frequency of mid-air collisions between aircraft. Unfortunately, it is widely known that in congested airspace, the use of the TCAS may actually lead to induced collisions. Therefore, further research regarding TCAS logic is required. In this paper, an encounter model is formalised to identify all of the potential collision scenarios that can be induced by a resolution advisory that was generated previously by the TCAS without considering the downstream consequences in the surrounding traffic. The existing encounter models focus on checking and validating the potential collisions between trajectories of a specific scenario. In contrast, the innovative approach described in this paper concentrates on quantitative analysis of the different induced collision scenarios that could be reached for a given initial trajectory and a rough specification of the surrounding traffic. This approach provides valuable information at the operational level. Furthermore, the proposed encounter model can be used as a test-bed to evaluate future TCAS logic changes to mitigate potential induced collisions in hot spot volumes. In addition, the encounter model is described by means of the coloured Petri net (CPN) formalism. The resulting state space provides a deep understanding of the cause-and-effect relationship that each TCAS action proposed to avoid an actual collision with a potential new collision in the surrounding traffic. Quantitative simulation results are conducted to validate the proposed encounter model, and the resulting collision scenarios are summarised as valuable information for future Air Traffic Management (ATM) systems. 相似文献
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长江上海段圆圆沙警戒区航行规则的思考 总被引:1,自引:0,他引:1
通过对长江上海段圆圆沙警戒区通航现状和船舶流向的分析,结合定线制规则、海员通常航行习惯和船舶操纵等相关知识,给航经此水域船舶的安全航行和船舶间的避碰提出一些可行性的建议,这些建议对保障船舶在该水域安全航行具有重要意义。 相似文献
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我国铁路正准备修建三线桥甚至四线桥,现行规范及研究只涉及到两线桥的疲劳检算。将三线铁路桥梁列车相遇的复杂随机过程问题简化为较简单的概率问题,推导出铁路三线钢桁梁桥列车两两相遇概率及相遇次数、三线相遇概率及相遇次数,通过模型处理和简化,推导出三线钢桁梁桥疲劳检算三线系数的近似计算式。算例说明,应用近似计算式将使三线钢桁梁桥的疲劳检算变得简单、方便。该研究思路和方法也为四线钢桁梁桥及更多线钢桁梁桥的疲劳检算多线系数研究提供依据。 相似文献
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三线铁路桥梁疲劳检算的三线系数 总被引:2,自引:2,他引:0
铁路桥梁结构的疲劳寿命主要取决于桥梁结构构造细节、活载作用效应特征和活载作用次数。从列车上桥时刻的随机分布特征及列车相遇对桥梁损伤的累积作用出发,分析三线铁路桥梁结构疲劳检算中三线系数的影响因素。分析结果表明,三线系数只与各线列车的最大作用效应、列车运营密度(发车时间间隔)以及在桥上的持续时间有关。基于遭遇概率理论,推导三线系数的计算公式。采用该公式计算的三线系数与现场调查分析法所得结果基本一致。 相似文献
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The traffic collision avoidance system (TCAS) acts as a proverbially accepted last-resort means to resolve encounters effectively, while it also has been proven to potentially induce a collision in the hectic air traffic. Thus, new research considering the impact on safety is required to increase the airspace capacity based on a comprehensive analysis and accurate flight evaluation. In this paper, a causal encounter model is proposed to extend the TCAS logic considering the horizontal resolution manoeuvres, which could be used as the auxiliary supports when a potential collision is predicted in the vertical dimension. Based on the generated state space, the model developed in the graphical modelling and analysis software (GMAS), not only provides a better comprehension of the potential collision occurrences for risk assessment by representing the cause-effect relationship of each action, but also aids the pilots in the involved aircraft to make a cooperative and optimal option. Quantitative simulation results are conducted to validate the feasibility and effectiveness of the encounter model with horizontal resolution. The resulting collision scenarios are further investigated to illustrate that the risk rate of TCAS logic failures is expected to reduce by shortening the pilot's response delay, and the computational efficiency is competent in dealing with multi-threat scenarios. 相似文献
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Fujio Kaneko 《Journal of Marine Science and Technology》2002,7(1):1-16
At the 62nd MSC conference (MSC62) in 1993, the UK proposed a new methodology for the consideration of safety regulations.
This method is called formal safety assessment (FSA). FSA is an application of probabilistic safety assessment (PSA). Risk
is used as an index of safety. One of the most important parts of FSA is to evaluate the risk to a ship when it is equipped
with the safety measures recommended by the proposed safety regulations. The National Maritime Research Institute (NMRI, formerly
the Ship Research Institute) has been developing a method which allows the risk to be obtained holistically by utilizing a
scientific method. To obtain the risk, the probability and consequences of every accident must be evaluated. This paper examines
the following points: (a) a holistic methodology for risk evaluation; (b) a method used in the process of estimating the probability
of collision; (c) a method to reduce the numbers of fire escalation scenarios; (d) a trial risk evaluation of cabin fire.
Received: January 10, 2002 / Accepted: April 18, 2002 相似文献
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船舶会遇过程中避碰阶段的划分与量化 总被引:10,自引:3,他引:7
在分析船舶会遇的基础上,就碰撞危险的含义、船舶会遇避碰的各个阶段进行了定性和定量的分析,提出以TCPA为基础的船舶操纵避碰阶段划分的有关建议,为船舶碰撞责任划分和船舶操纵行为提供参考。 相似文献
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船舶自动避碰方法的研究 总被引:20,自引:5,他引:15
本文提出了利用框架式专家系统与数理分析相结合的仿人智能避碰方法,经过计算机仿真表明,实现了海域无约束船舶避碰方案的自动编制,为船舶自动避碰系统的研究迈开了可喜的一步 相似文献
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