自保护相依多部件系统的预防维修建模及策略优化

自保护技术作为自愈技术的一种,能够使系统在环境或工况条件变化的干扰下以较高可靠性运行。本文构建了一个新的具有相依主要部件和辅助部件的系统可靠性模型,其中主要部件的退化速率与工作中的辅助部件的数量有关。此外,基于定期检测和预防维修策略,本文利用半再生过程技术求解了系统的长期运行平均成本,并以长期运行平均成本最小化为目标给出了系统的最优预防维修策略。最后,以镗刀系统为例,利用所提方法给出了预防更换阈值和检测周期的最优值,以期望为实际维修行为决策提供理论参考。

Preventive Maintenance Modeling and Policy Optimization for Self-protection Systems with Dependent Units

As a kind of self-healing technology, self-protection technology can make the system operate with high reliability under the interference of environments or dynamic working conditions. In this paper, a new reliability model for systems with dependent main and auxiliary units is developed, in which the degradation rate of the main unit depends on the number of operating auxiliary units. In addition, based on the periodic inspection and preventive maintenance strategy, the long-run average cost of the system is derived by the technique of semi-regenerative process and the optimal preventive maintenance strategy of the system is given with the goal of minimizing the long-run average cost. Finally, taking the boring tool system as an example, the optimal values of preventive replacement thresholds and inspection period are given by the proposed method, which is expected to provide a theoretical reference for practical maintenance decision.