Importance Measure-based Maintenance Optimization Strategy For Pod Slewing System

With the rapid progress of computer,communication and embedded technology,under the guidance of actual demand,the control system continues to develop in the direction of integration and intelligence.The components of high integration control system are various and complex in structure.Once such system fails,it will cause huge economic losses and sometimes catastrophic casualties.Therefore,the reliability analysis of the system is very important It has become an important work that must be considered in the operation and maintenance stage.Pod slewing system is a kind of complex hydraulic control system,which is the necessary control equipment to realize ship yaw or reverse.Its performance directly affects the mobility and flexibility of the ship.At present,the research on POD slewing system mainly focuses on the system design and control theory,but the research on the reliability of the system is less.In recent years,importance theory and methods have been applied to fault analysis of complex systems.However,there is no analysis and modeling of pod slewing system from the perspective of complex system reliability,and the existing maintenance strategy does not solve the problem of maintenance sequence of slewing system components from the perspective of importance.Based on these practical problems,this paper studies the system as follows:Firstly,the design structure and working principle of the pod slewing hydraulic system are described and analyzed,and the problems existing in the current maintenance strategy of the pod slewing system are described in detail.The typical system model and its reliability calculation method are studied,and the Integrated importance calculation formula of two-state system under gamma distribution is derived.Then Integrated importance measure of the hybrid system under Gamma distribution is extended and applied.The calculation formula of Integrated importance of typical system model under Gamma distribution and the influence of scale parameters and shape parameters of components on Integrated importance are derived,and the physical significance is given.Taking the hydraulic energy hybrid system of Boeing 737 as an example,the Integrated importance analysis and simulation case analysis of the components of the system are carried out.The results show that the Integrated importance of components is positively correlated with failure rate and scale parameters,and negatively correlated with shape parameters in the hybrid system under Gamma distribution.Finally,Integrated importance analysis method is applied to the polymorphic complex system.According to the design and working principle of the pod slewing hydraulic system,the key components of the system are determined,and nine types of34 components of the system are extracted.Based on the importance degree,the reliability model of the pod slewing system is established,and the weak components of the system are identified by comparing the two importance degree methods.According to the results of importance analysis and the maintenance cost of each component,the maintenance optimization strategy under different time and maintenance cost is proposed.Finally,the maintenance sequence of hydraulic system components is determined.It brings great convenience for engineers to maintain and maximize the performance of the system.