Research On Integrated Availability Importance Measure Analysis And Maintenance Optimization Of Multistate Complex System

Importance measure is widely used to identify the weak links of the system and provide support for system reliability improvement and maintenance strategy formulation.At present,the importance measure of the system is mainly focused on the two-state hypothesis(working/failure)and the reliability importance measure of the multi-state system,ignoring the impact of maintenance activities.Therefore,considering the influence of system reliability and maintainability,it becomes an urgent problem to analyze the integrated availability importance measure for multistate complex systems.In view of the above problems,this paper takes multi-state complex system as the research object and carries out research,and finally completes the following research work:First,an integrated availability importance measure model based on proportional hazards model was established.Aiming at the influence of state on the system,the traditional Availability Importance Measure(AIM)was expanded with state probability,state transition rate and repair rate.Building Integrated Availability Importance Measure(IAIM)and State Integrated Availability Importance Measure(SIAIM).In order to analyze the integrated availability importance measure of system from two dimensions of time and state,an integrated availability importance measure analysis method of multi-state system based on proportional hazards model was constructed.Numerical example analysis shows that the IAIM based on proportional hazards model can evaluate the system more comprehensively than the Integrated Importance Measure(IIM)and Performance Utility Importance Measure(PUIM).By analyzing the sensitivity of parameter k,η,γ of the proportional hazards model and parameter ω,σ of the repair rate function,the influence rule of each parameter on the integrated availability importance measure of component was obtained.Second,the integrated availability importance measure of lithium battery electrode production line was analyzed.In order to solve the problem of integrated availability importance measure parameters,the parameter estimation method of proportional hazards model based on particle swarm optimization and linear regression and the parameter estimation method of repair rate based on maximum likelihood estimation were proposed,which effectively solved the problems of slow convergence speed and low accuracy due to the influence of sample size.Furthermore,the influence of each device state on component performance was studied by SIAIM,and the key states of each device were determined.The key equipment affecting the system availability was determined by IAIM,which provided the basis for further formulating reasonable maintenance strategy.Third,an opportunistic preventive maintenance strategy based on the integrated availability importance measure was proposed.Taking the integrated availability importance measure of equipment as the influence index,the opportunistic preventive maintenance strategy model of lithium battery electrode production line was established.The opportunistic maintenance decision table of lithium battery electrode production line was obtained by taking the ratio of equipment opportunistic maintenance coefficient and integrated availability importance measure as the opportunistic maintenance threshold value,aiming at minimizing the total maintenance cost.Through comparative analysis,it is found that opportunistic preventive maintenance can effectively reduce the number of maintenance while ensuring the availability and cost of the production line,and prevent maintenance surplus.