Fmeca On, And Fracas Uav Power System Applications

In the course of Unmanned Aerial Vehicle (UAV) design, several problems exist in the reliability works process. Due to the lack of the unified cooperation and effective management, it is definitely difficult to reach a unanimous agreement and convergence forces by different departments. The lack of uniform reliability analysis approaches and associated guides results many reliability works which need to deal immediately are difficult to start. It's inefficient and poor information exchanging between different departments of a company because of the lack of uniform reliability management platform and even some departments still record the fault information in a manual way. It's definitely difficult to remove the reliability level and therefore cumbers the reliability improvement of the UAV power system.A disciplined and aggressive closed loop Failure Reporting, Analysis, and Corrective Action System (FRACAS) is considered an essential element in the early and sustained achievement of the reliability in equipment. The essence of a closed loop FRACAS is that failures and faults of equipments are formally reported, analysis is performed to extent that the failure cause is understood, and positive corrective actions are identified, implemented, and verified to prevent further recurrence of the failure. The Failure Mode, Effects, and Criticality Analysis (FMECA) is an essential function in design from concept through development. The usefulness of the FMECA as a design tool and in the decision making process is dependent upon the effectiveness with which problem information is communicated for early attention.To overcome the aforementioned issues, several aspects of the work below have been finished in this thesis.(1) A suggestion that describes how to start the UAV power system reliability work is proposed to coordinate the different department to let them understand their responsibilities and tasks, these departments include the product design department, quality and reliability department, as well as product providers, etc.(2) The FMECA of the UAV power system which following the rules of"Guide to failure mode, effects and criticality analysis"(GJB1391-2006). An FMECA report is generated finally. The FMECA report establishes a basis for following reliability work.(3) On the base of FMECA, a FRACAS system which following the rules in GBJ841 and the needs from the aircraft manufacturing company has been developed. A normative procedure of reliability work has been built.(4) In the research of Criticality Analysis (CA), The fuzzy set theory has been used in Criticality Analysis, and the approach is called FRPN (Fuzzy Risk Priority Number) contrary to the subjectivity of CA process. It's a more wonderful method.Through the work above, the normative procedure of reliability work has been built, the responsibilities and tasks of all departments are understood, the efficiency of reliability work has been removed. It significantly improves the reliability of the UAV power system, also gives some reference to the follow-up UAV.