Study On Key Technologies Of Reliability For Complex System Based On GO Methodology

Goal Oriented(GO)methodology is a success-oriented method for system reliability analysis,and it is more suitable for reliability analysis of complex systems with multi-state,Closed-Loop Feedback,time-sequence,dynamics,and complex correlations.Furthermore,GO model is established according to system principle diagram,flowchart or engineering drawing directly.It directly reflects the function and structure of a system,and has objectivity,normative and good operation characteristics.This paper improves the reliability modeling method and reliability analysis method based on GO methodology for multifunction repairable systems with multiple fault modes,complex correlations,multi-input Closed-Loop Feedback,multi-state stable performance unit etc.On this base,the reliability optimization allocation method based on the GO method and the reliability assessment method based on the GO method for such complex systems are firstly proposed,respectively.Moreover,Reliability integration technology based on the GO method for such complex systems is formed preliminarily,and the corresponding software is developed.All in all,this study not only improves the GO method greatly,but also it widens the application of GO method.Firstly,the reliability modeling method and reliability anlaysis method based on GO method for such complex systems are improved systematacially,and the corresponding analysis process is formulated in this paper.In aspect of establishing reliability model,this study improves GO operator in the aspects of operator data,operator type,and operator operation formula,and a two-level GO model for such complex systems is proposed.In aspect of reliability analysis,this study improves quantitative analysis technology and qualitative analysis technology of GO method,and supplements the GO operation rules.Then,the reliability optimization allocation method based on the GO method is firstly proposed,and the corresponding allocation process is formulated in this paper.For the allocation of the fault rate of system function,this study proposes the compound allocated method combining Fuzzy Analytic Hierarchy Process allocation method with new system and old system allocation method.For the allocation of the fault rate and maintenance rate of design unit,this study proposes the optimization allocation method with the goal of weighing the reliability index and maintenance index based on GO method.Furthermore,this study proposes the improved Genetic Algorithm and improved Ant Colony Optimization for solving the optimization allocation problem of this paper.Later,the reliability assessment method based on the GO method for such complex systems is firstly proposed,and the corresponding assessment process is formulated in this paper.Combined with the parameter estimation of failure rate of unit,the average lifetime point estimation method based on GO method is put forward.Combined with the fiducial distribution of failure rate of unit,the lower system reliability confidence limit assessment method based on GO method is proposed.Combined with the fiducial distribution of failure rate and maintenance rate of unit,the lower availability confidence limit assessment method based on GO method is proposed.Furthermore,the integrated software based on key technologies of GO method for such complex systems is developed in this paper,which makes the GO methodology reliability integration technology to apply preliminary in engineering.The customized GO software is also successfully developed based on this integrated software.Not only are a new utility tool provided for such complex system reliability engineering,but also the practical and economic value of GO method integration software are embodied.Finally,taking the electro-hydraulic control system of a Power-shift Steering Transmission as an example,its reliability modeling and reliability analysis based on the GO method are conducted;its reliability & maintainability tradeoff optimization allocation with the goal of system availability under the objective of the minimul cost is conducted based on the GO method;the system average lifetime point estimation,lower system reliability,and availability confidence limit are obtained by the reliability assessment method based on the GO method.The analysis results show the rationality,engineering applicability and superiority of the key reliability technologies based on the GO methodology for such complex systems.All in all,a new approach for reliability modeling,reliability analysis,reliability allocation,and reliability assessment of such complex systems is provided in this paper.