Robust Maintenance Decision-making Issues For Urban Rail Traffic Operational Equipments

Based on equipment maintenance decision-making,the paper introduced concepts which include statistics and robustness of cybernetics,and proposed the thought of steady maintenance,which refers to a maintenance decision-making which can guarantee the reliability of the system equipment and network under the equipment state and fault conditions uncertain circumstance.The paper takes all operating equipment life cycle management goal as orientation,which means that under the premise of system reliability and security,to arrive the goals of equipment life cycle value maximization and management cost minimization.To solve the existing problem of operating equipment maintenance decision characteristics,considering different decision levels,the paper from three aspects which include maintenance concept of security,maintenance management mode,and maintenance and support strategy to study the robust maintenance decision problem of urban rail transit operation equipment.The result of this paper deeply studies the theory and method of urban planning transportation operation and maintenance support,and solve the practical problem of decision-making method and technical level of operation,and maintenance support,which also improve the health management ability of operation equipment,as the same time promoting the synchronous technology upgrade of operation and maintenance guarantee and planning and construction.The innovations and contributions of this paper are mainly embodied in the following aspects:First of all,the concept of robustness is applied to the maintenance of urban rail transit operation equipment for the first time,and the author innovatively puts forward the robust maintenance decision of rail transit operation equipment.To guarantee the reliability of operation equipment and the robustness of system maintenance,the paper proposed methods through three aspects which refers to preventive maintenance decision of network,regional maintenance decision and resource allocation of regional maintenance guarantee.Secondly,based the application of Weibull distribution to fit the operating equipment reliability function,the paper puts forward mixed failure rate adjustment factor,to depict the equipment recursion decreasing and increasing failure rate after maintenance activities,and introduce the factor into the reliability function to describe the equipment reliability more accurately.With the aim of minimizing maintenance costs,the paper built the preventive maintenance decision model with reliability as constraint,and to solve the optimal reliability maintenance activities under the implementation cycle and maintenance costs through MATLAB.Through practical cases,it is verified that the maintenance decision model can provide a more practical preventive maintenance cycle of equipment degradation process under the condition of ensuring equipment reliability.At the same time,the implementation time of maintenance activities with minimum maintenance cost is given,under different reliability requirements,which can provide implementation guidance and reference for the maintenance of different equipment of rail transit system.Thirdly,to solve the uncertain problems of the equipment preventive maintenance state parameters measurement error and cognitive recognition,the paper proposes equipment state probability correlation function and status information augmented matrix,then puts forward a constrained Hervis criterion robust optimization method,and establishes Markov process maintenance decision model with the aim of minimizing maintenance costs.Based on rail transit car bogie component failure and maintenance data,the paper demonstrated the effectiveness of proposed model,and also verified maintenance strategy optimization performance efficient under the uncertain condition of equipment state and fault.Fourthly,maintenance network design is key component of urban rail transit equipment steady maintenance decision.Considering the vulnerable node in the network maintenance,the paper determines the principle that the distance between maintenance guarantee node and important node as close as possible.Considering the maintenance network construction costs to minimize,the author builds the double goal maintenance network planning model,and designs the NSGA-Ⅱ algorithm to obtain Pareto solution of model.Research results show that the model and the algorithm is effective.Through the proposed model to build a maintenance network can not only improve the maintenance efficiency of the entire network operation equipment under a certain cost,but also make the most effective response to the sudden failure of fragile nodes,thus increasing the stability and reliability of the entire network.At the same time,the improvement of network maintenance efficiency and system reliability are depended on the cost of increasing the construction cost,which provides a quantitative reference direction and basis for the decision makers to balance the cost,efficiency and reliability.Finally,the paper proposed a network regional maintenance resource allocation method,and based on subnet area potential biggest maintenance as requirements,applied Monte Carlo simulation to configure the network maintenance support resources.On one hand,this method increases the maintenance support resources costs,on the other hand,it can maintain the efficiency of the resource scheduling and maintenance activities and operating equipment to the greatest degree under the circumstance which uncertain time and location of network operating fault occur.The research is suitable to allocate network resource for network which require high reliability and stability.The paper based on the active,preventive and robust maintenance characteristic,and from three aspects which refer to steady maintenance concept,maintenance management mode innovation and maintenance guarantee strategy optimization to build urban rail transit equipment maintenance decision model and proposed solve method.The research has significant meaning to improve traffic operations security theory and make beneficial attempt to urban planning method.