考虑随机冲击与冗余的列控车载设备可靠性模型与预防性维修策略

Reliability Model and Preventive Maintenance Strategy of Train-Control On-Board Equipment Considering Random Shock and Redundancy

列控系统的安全苛求对车载设备的可靠性提出了更高的需求,有效的可靠性模型与合理的维修策略对预防潜在故障、提高设备可靠性具有重要意义。针对现有车载设备可靠性建模和维修策略考虑因素不全面的问题,提出了一种考虑随机冲击与冗余的可靠性模型构建方法与一种不完美维修条件下的预防性维修模型。首先,考虑自然性能退化和外界随机冲击,针对车载设备及其冗余分别建立不同的性能退化模型并计算相应的可靠度函数;其次,利用Copula函数求解联合分布函数作为整体可靠度函数,在可靠度阈值约束下,通过单个预防性维修周期内的可靠度函数求解预防性维修间隔,同时考虑不完美维修对于维修策略的影响,以可靠度阈值和预防性维修次数作为决策准则,构建车载设备全生命周期内的维护费用率模型;最后,以列车自动防护控制单元(Automatic Train Protection Control Unit,ATP-CU)为例进行数值仿真,验证所提模型的有效性。结果表明:提出的基于Copula函数求解车载设备及其冗余的可靠性建模方法相比传统的独立可靠性分析方法能够更好地把握其性能的演化情况;在仿真环境下,当可靠度阈值为0.85、预防性维修次数为7次时,ATP-CU及其冗余全生命周期内的最小维护成本率为21.47元·d-1。

The safety requirements for train control system have put forward higher demands on the reliability of on-board equipment,and an effective reliability model and reasonable maintenance strategies are important for preventing potential failures and improving equipment reliability.In view of the issues that the existing problems on on-board equipment reliability modeling and maintenance strategy are not comprehensive,this paper proposed a reliability model construction method considering random shock and redundancy and a preventive maintenance model under imperfect maintenance conditions.Firstly,considering the natural performance degradation and external random shock,different performance degradation models are established,and the corresponding reliability functions are calculated for the on-board equipment and its redundancy,respectively.Secondly,the Copula function is used to solve the joint distribution function as the overall reliability function;and the preventive maintenance interval is solved based on the reliability function through a single preventive maintenance cycle under the constraint of reliability threshold.At the same time,the impact of imperfect maintenance on the maintenance strategy was considered,and the maintenance cost rate model for the whole life cycle of the on-board equipment is constructed using the reliability threshold and the number of preventive maintenance as the decision criteria.Finally,numerical simulations were conducted with ATP-CU(Automatic Train Protection Control Unit)as an example to verify the effectiveness of the proposed model.The results show that the reliability modeling method based on Copula function for solving the on-board equipment and its redundancy proposed in this paper can better grasp the evolution of its performance compared with traditional independent reliability analysis methods.In the simulation scenario,the minimum maintenance cost rate for the ATP-CU and its redundancy in a full life cycle is 21.47 CHY/d^(−1) when the reliability threshold is 0.85 and the number of preventive maintenance is 7.