Optimal intervention policy of emergency storage batteries for expressway transportation systems considering deterioration risk during lead time of replacement
研究了高速公路交通系统中应急蓄电池在更换前置期内持续退化带来的风险，提出基于随机控制框架的最优干预策略，通过案例验证可降低5.49%的全生命周期成本。
An emergency storage battery (ESB) is an important asset to ensure the reliability and safety of complex technological systems. Even if an asset owner decides to replace a deteriorated ESB in expressway transportation systems , a lead time (LT) from ordering replacement parts to delivery is inevitable because the replacement parts cannot be stockpiled. During the LT, the ESB continues to deteriorate, i.e., the risk of deterioration continuously increases. If the LT has a non-negligible length, it is necessary to find intervention policies that appropriately consider the risk during the LT. In this study, we propose a methodology to derive optimal intervention policies by explicitly considering deterioration risk during the LT in a stochastic control framework. Specifically, the geometric Brownian motion is statistically estimated as the deterioration process of the ESB, and an optimization model is proposed to find the optimal intervention policy. The proposed methodology is applied to a case study on an expressway transportation system. In the case study, a sensitivity analysis is also performed to obtain practical implications through a life cycle cost (LCC) comparison. Our findings show that the proposed methodology can reduce the LCC by 5.49% compared with when the LT is not considered.