摘要
系统的健康状态评估是故障预测和健康管理的关键环节,其前提是对故障机理的准确刻画。比例风险模型在可靠性工程中广泛用于描述寿命和协变量对故障时间的影响。工程实际中的协变量过程大多具有随机性,给评估比例风险退化系统的健康状态带来极大的挑战。针对协变量过程具有马尔可夫性质的比例风险模型,提出一种迭代算法近似评估系统的健康状态。该方法首先基于离散化思想构建寿命和协变量状态在单位时间内的联合一步转移概率矩阵,然后通过相邻单位时间的状态转移规律推导条件可靠性和平均剩余寿命等关键健康指标的迭代计算公式。通过两个实际案例验证该迭代算法的有效性:案例一通过与解析法的对比表明迭代算法的评估结果随着离散化水平的提高不断趋于解析值,并由此给出离散化水平的设置准则;案例二通过与转移矩阵近似法的对比表明迭代算法具有计算速度快和内存需求小等优点。
Health assessment is of crucial significance for prognostics and health management.Its accuracy relies heavily on the failure mechanism of the system under consideration.Proportional hazards models are widely adopted in reliability engineering for describing the joint effects of age and covariates on failure time.In many practical situations,the covariate progress is stochastic,making it of great challenge to assess the health state of a system in the proportional hazards model.An iteration method is developed to approximately address the problem of health assessment in the proportional hazards model with a Markovian covariate process.First,the one-step transition probability matrix for the joint process of age and covariate is constructed.Based on the state-transition properties of consecutive time units,the calculation formulas of some health indices such as conditional reliability and remaining useful time are provided with proof.The effectiveness of the proposed approach is verified by two practical examples.In example 1,the comparison with the analytical method shows that the accuracy is increasing with the increase of discretization level,and a recommendation for determining a discretization level is provided.In example 2,the comparison with the transition matrix method shows that the proposed recursive method can produce accurate estimations efficiently with low memory requirements.
作者
郑锐
周一帆
ZHENG Rui;ZHOU Yifan(School of Mechanical Engineering,Southeast University,Nanjing 211189;School of Management,Hefei University of Technology,Hefei 230009)
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2023年第10期366-373,共8页
Journal of Mechanical Engineering
基金
国家自然科学基金资助项目(72071044,71671041)。
关键词
比例风险模型
健康评估
条件可靠性
平均剩余寿命
迭代算法
proportional hazards model
health assessment
conditional reliability
mean residual life
recursive algorithm
