基于RAMS的地铁信号系统运营维护管理研究

莫志刚

摘要

根据RAMS（Reliability、Availability、Maintainability、Safety）体系结构，系统的安全性与可用性由系统的可靠性、可维护性来保障，且系统的可用性与安全性之间存在相互作用。然而，目前大多数地铁信号设备的可靠性基础研究数据主要停留在理论预计，没有通过实际运营数据进行可靠性验证，信号系统维护策略的制定主要依赖经验，设备维护方法与时机不当，设备维护资源分配不科学，造成设备故障率与维护费用居高不下，影响信号系统在运营中的安全性与可用性指标。如何运用RAMS体系研究地铁信号系统在满足一定的安全性与可用性的前提下，降低信号系统故障率，节省信号系统的维护费用，是关系到我国地铁交通持续性发展的工程管理问题。

基于RAMS体系规范，论文构建了地铁信号系统的RAMS评价指标体系；运用威布尔函数模型预测了信号设备的可靠性，构建可靠性解析模型计算了信号系统可靠性指标的敏感度，建立了信号系统动态安全风险评估模型；提出了综合考虑设备综合关键度，在设定的安全风险阈值与可用度的条件下，通过计算得到信号系统平均可靠性与维护费用同时最优解的信号系统维护策略；开发了信号系统运营综合维护管理平台。具体研究内容如下：

（1）研究RAMS体系规范，建立了地铁信号系统RAMS的评估体系。根据行业相关标准与规范要求，定义了地铁信号系统RAMS的评价指标，构建了地铁信号系统的安全风险评估体系，提出了基于状态矢量数据与概率理论的地铁信号系统可靠性解析模型。

（2）分析地铁信号系统安全性（S）与可用性（A）的边界条件，研究信号设备可靠性（R）预测的时变规律与信号系统的安全风险评估。运用威布尔函数模型分析了信号系统设备可靠性的分布规律，建立可靠性解析模型计算了信号系统可靠性指标对相关参数的敏感度；提出了基于信号设备可靠性预测的信号系统动态安全风险评估模型与分析方法。

（3）分析地铁信号系统安全性（S）、可用性（A）、可靠性（R）与维护费用之间的相互作用，研究信号系统的维护策略。根据设备故障后对信号系统的安全性、可用性、可维护与经济性的影响程度定义了设备综合关键度，提出了基于设备综合关键度的设备维护分类方法；以信号系统的动态安全风险评估的阈值与设定的系统可用度为约束条件，建立系统的平均可靠性与维护费用的多目标函数，采用多目标优化算法获取Pareto解集。基于以上的分析与研究，提出了基于设备综合关键度与多目标优化算法解集相结合的信号系统维护策略。

（4）基于以上的理论与方法研究，开发了集信号系统的设备状态监测、信号系统安全风险动态分析与设备维护方案推送一体化的信号系统运营综合维护管理平台。并在深圳、昆明、南宁等地铁运营中得到了应用。实践证明，该平台的使用降低了信号系统的故障率与维护费用，提高了设备的可维护性，保障了系统的安全性与可用性，验证了论文中理论研究的科学性与合理性，并对地铁其他系统的维护管理研究具有一定的借鉴意义。

关键词：地铁；信号系统；RAMS；威布尔分布；维护策略

Abstract

According to the RAMS (Reliability, Availability, Maintainability, and Safety) architecture, the system reliability and maintainability are guarantees for system safety and availability, and there is an interaction between availability and safety of the system. However, currently, basic research data on the reliability of most metro signal equipment is mainly used for theoretical predictions, while the reliability of data has not been validated by actual operation data. The formulation of signal system maintenance strategies mainly relies on experience, thus, improper equipment maintenance methods and timing, and unscientific allocation of equipment maintenance resources could result in high equipment failure rates and maintenance costs, affecting the safety and availability indicators of the signal system in operation. How to use the RAMS-based system to study the metro signal system under the premise of satisfying certain safety and availability, reduce the failure rate, and save the maintenance cost of the signal system, is an engineering management problem related to the sustainable development of metro in China.

Based on the RAMS system specifications, this thesis constructs the RAMS evaluation system for the metro system. The Weibull distribution has been used to predict the reliability of signal equipment, and the reliability analytical model has been built to calculate the sensitivity of signal system reliability index, and then a dynamic evaluation model of signal system safety risk has been built. Moreover, a signal system maintenance strategy has been proposed, which comprehensively considers the equipment comprehensive criticality and system average reliability and maintenance cost to get an optimal performance under the set of safety risk threshold and availability conditions. A comprehensive maintenance and management platform forsignal system operation is developed. The specific research contents are as follows:

(1) Based on the study of the RAMS system specifications, the evaluation system of the RAMS of the metro signal system has been established. According to related industry standards and specifications, evaluation criteria of the RAMS of the metro signal system has been defined, and the safety risk assessment system of the metro signal system has been constructed, also, reliability analysis model of the metro signal system is proposed based on state vector data and probability theory.

(2) The boundary conditions of safety (S) and availability (A) have been explored, and the time-varying law of the reliability (R) prediction of signal system equipment and safety risk evaluation of the signal system has also been studied. The Weibull distribution has been used to analyze the distribution law of signal system equipment reliability. Also, the reliability analytical model has been built to calculate the sensitivity of signal system reliability index to related parameters. And a dynamic evaluation model and analysis method of signal system safety riskhas been proposed based on the reliability prediction of the signal equipment.

(3) Interactions among safety (S), availability (A), reliability (R), and maintenance cost has been analyzed, and the maintenance strategy of the signal system has been investigated. According to the impact of equipment failure on system safety, availability, maintainability and economy, the comprehensive criticality of equipment has been defined, based on which an equipment maintenance classification method has been proposed. Taking the threshold of dynamic safety risk evaluation of the signal system and set system availability as constraints, to construct a multi-objective function regarding the equipment average reliability and maintenance cost, and obtains Pareto solution set by using a multi-objective optimization algorithm. Based on the analysis and research above, a signal system maintenance strategy has been proposed based on the combination of comprehensive criticality of equipment and multi-objective optimization algorithm set.

(4) On the basis of the above theory and research, an integrated maintenance management platform of signal system operation has been developed, which provides functionalities such as equipment state monitoring, safety risk dynamic analysis of the signal system and equipment maintenance program push. The platform has been applied in metro operations in Shenzhen, Kunming, Nanning and so on. The practice has proved that the use of the platform reduced the failure rate and the maintenance cost of the signal system, improved the maintainability, ensured the system safety and availability, and verified the scientificness and rationality of theoretical research in the paper. The research can be potentially applied to the maintenance and management of other metro systems.

Keywords: Metro; signal system; RAMS;safety; reliability; maintenance strategy;