Research On The Application Of GO-FLOW Methodology In The Reliability Analysis Of Electro-Hydrostatic Actuator

Electro-Hydrostatic Actuator(EHA)is a widely used pump-controlled actuation system in current aeronautical engineering areas,which has good safety,high efficiency,more reliable,easy maintenance and other advantages.In the process of aircraft flight,EHA system is used to operate the aircraft rudder,control flight attitude and trajectory and ensure the smooth flight of the aircraft.So,for security reasons,it is necessary to fully ensure the reliability of the EHA actuator system.Therefore,analyzing the reliability of the EHA is the most important step to develop aircraft and ensure security,so the application of the GO-FLOW(GF)methodology in the reliability analysis of EHA is researched in this paper.According to some problems need to be solved in the reliability study of GF methodology and EHA system,some aspects have been researched deeply in this paper,such as reliability modeling of EHA,solution to logical feedback loops,shared signal's correction,reliability quantitative calculation,changing rule fitting,redundancy design and so on.The main contents are as follows:(1)At first,the engineering structure diagram of EHA is constructed,and the operation principle of EHA is analyzed in detail.Based on reasonable division in the function unit,the appropriate GF operators are used to simulate the corresponding components and the relationship between components.(2)For the difficult problem that the GF model chart does not allow the existence of circles,the system feedback relationship are described by Boolean equation.The Boolean equation is solved by the idea of Boolean algebra,and the feedback signal of the system is simulated.Then the GF model chart of the EHA reliability is established accurately.(3)Combining GF model chart with the operation rules of operators and modifying shared signals by the reduction method,the reliability of the EHA system is calculated accurately and the data results are fitted in Matlab.In addition,compared with GO methodology,the characteristics and advantages of GF methodology are analyzed from the operation difficulty,applicability and other aspects.(4)At last,the calculation results are analyzed and the weak link of EHA is found.After the sensitivity of the system reliability to components parameters is determined,the redundancy design of the key components on the basis of GF methodology is finished.Then the optimal redundancy allocation is determined so that the overall performance of the system could achieve the optimal level.The results show that the application of GF methodology in calculating EHA reliability is feasible and efficient,and its result is accurate and reliable.At the same time,the redundancy configuration scheme of EHA designed by GF methodology has a significant effect on improving the reliability of the system,which provides the effective theoretical support for reliability design and improvement.