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基于FTF方法的无人机液压与冷气系统可靠性分析

【作者】 冯军

【导师】 黄振南;

【作者基本信息】 电子科技大学 , 机械制造及其自动化, 2011, 硕士

【摘要】 近百年来,无人机的发展经历了最初问世到广泛应用的过程,由于其自身特点和优越性能,它在各国航空领域的地位愈显重要,随着无人机技术高端化和先进化,其组成和系统越来越复杂,而由于受操作技术的熟练性和远程遥控的超长性影响,无人机重大事故经常发生,为了避免事故发生,可靠性工作尤显重要,我们在早期就应该做好其可靠性工作,做到防患于未然。飞机液压与冷气系统故障是各种飞机常见的多发性故障,对整机危害严重。液压与冷气系统也是无人机重要组成部分,对其故障模式进行系统分析以提高可靠性从而降低无人机飞行风险是本论文的主要研究内容,FMECA和FTA是分析产品故障因果关系的常用技术,FMECA是一种上行的追踪,而FTA是下行的分解,这两种分析方法各有优缺点,将两种分析方法结合起来使用的FTF方法是根据被分析对象的复杂程度和约定层次要求,以及时间和费用限制等条件,综合FMECA和FTA对其故障模式进行分析,找出薄弱环节,改进产品设计的一种有效方法。本论文采取FTF方法对无人机液压与冷气系统进行故障分析,找出故障原因,并提出预防措施。在FMECA分析中,论文介绍了FMECA分析的原理步骤及注意事项,在FTA分析中,本论文介绍了传统FTA分析方法和模糊FTA分析方法的相关内容,并在主液压与冷气系统的FTA分析中提出了T-S模糊门的建树方法以计算不同故障程度发生的模糊可能性。最后本论文简单介绍了结合FMECA、FTA和FRACAS方法的3F可靠性分析系统以及报警模块的构成和应用。

【Abstract】 Recent hundreds of years, the development of Unmanned Aerial Vehicle (UAV) experienced a process which is from first appeared to extensive application. Because of own characteristics and superior performance, its status of all countries in the aerospace sector become more and more important. With UAV technology high-end and advanced, its composition and system become more and more complex, and it will be easily affected by some factors such as longdistance of remote control and operating skills, so UAV’s accidents occurs frequently, in order to avoid the accidents, the reliability work on UAV is particularly important, we should do this early, to fix it before it breaks.The fault of hydraulic and air conditioning system of aircraft is all sorts of aircraft common fault, if happens, it will be dangerous for the aircraft. Hydraulic and air conditioning system is an important part of UAV, the main research of this paper is to analyse the failure mode of the system and improve the reliability of the system so as to reduce the flight risk of the UAV. FMECA and FTA are two commonly used technology to analyse relationship of product and its fault, FMECA is a tracing way from below, and the FTA is a decomposition method from top down, two analysis methods have their advantages and disadvantages, FTF method which combines two kinds of analysis method is based on the complexity of the analysis object, agreed time and cost requirements, then comprehensive FMECA and FTA to analyse, its aim is to find out the weak link, improve product designing, it’s an effective method to improve the reliability of the product.Using FTF method we analyse failure mode of hydraulic and air conditioning system of UAV to find fault reasons then put forward the preventive measures.In FMECA analysis, this paper introduces the principle of FMECA analysis steps , matters and needing attention. In the FTA analysis, the paper introduces the conventional fault tree analysis method and the fuzzy fault tree analysis. In the main hydraulic and air conditioning system FTA analysis, T-S fuzzy door tree-building method is introduced to calculate the fuzzy fault degree happen different possibilities.Finally 3F reliability analysis system which is based on FMECA, FTA and FRACAS is simply described in this paper, besides the structure and application of alarm module is introduced.

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