Study On Reliability Analysis And Modeling Of Automobile Inspection System

Recently the number of the automobile retention in our country has been increasing sharply and the problem of the automobile safe movement is more and more outstanding. The automobile safe reliability also is regarded as the important index which is the sign of appraising the automobile quality, and the automobile detection plays an important part in insuring the automobile safety drive. Also the reliability and work efficiency of the automobile detection system are the important index which is appraising the ability of the system checking the car. With the develepment of automobile detection technology, the people's request to the automobile detection system reliability is also more and more high. On the other hand owing to the raise of the automobile retention quantity year by year, the workload of automobile detection line must increase. Thus heavy work pressure, once the detection system appearing fault and consequentially that will influence the work efficiency of the automobile detection line and give the detection department to bring trouble and economic loss. On the other hand not only the quality request of the equipments provided for the factory to be very high, but also the request to the after-sales service of the factory to be more and more high, so the factory for creating their own brand will also provide the best after-sales service to satisfy the request of the large customers. Once detection line appearing fault, in spite of far or near, there will be an expert to rush through toward the spot in time, carrying on a maintenance and fix. If the automobile detection system usually appear problem, there will be the biggest wasted to the manpower,material resources and financial power. Therefore, the research meaning of this thesis is very important.This thesis passes the research to automobile detection system reliability, the purpose is to statistic the frequency and the invalidation form of the fault, on the basis of this, making use of the probability,the mathematics statistics and the knowledges that are related to the mathematics to establish mathematics model and analyse the emergence fault, find out the rule of the occurrence fault and get the fault rate and the reliability of the system. And then analyze the reliability of the automobile detection system by mathematics model. Make a forecast and estimate to the reliability of the detection system. The concrete research contents mainly has several aspects as follows:One, the fault data collection and the establishment of reliability databasePassed to the fault collections in the early days, collect100 earlier period fault data of 7 automobile detections station. According to structure characteristics and work characteristic of the detection system, I divide the automobile detection system into four small systems. Respectively build up fault part code,fault mode code and fault reason code. On this foundation built up a database, for carrying on to early fault analysis and research to lay foundation.Two, the research about the fault partition time distributed model According to the product of the life span characteristic curve in early days, firstly judged the fault of the detection system in early days take on gradually decrease trend, on this foundation built up mathematics model. This text first time research the distributed model of the automobile detection system the early fault partition time. Firstly extract early fault distribute of the partition time regulation of the automobile detection system. probability density function f(t),distributed function F(t) and the invalidation function.Three, the fault mode,influence and the bane degree analysis in early days(FMECA)1. the fault mode analysis in early days(FMA)Make use of the frequency chart and a square diagram method to analyse the fault part and code of the automobile detection system of the earlier period fault phenomenon. So as to find the primary fault part and the mainly code of the automobile detection system. Main earlier fault part is the calculator control system and equipments and the instrument system, the main fault mode is the lose efficacy of the light electricity switch (20%) and burn with the string bad(15%).2. The fault influence analysis in early days(FEA)For the first time to the automobile detection system of main fault mode to carry on reason and the influence analysis in early days, found out the reason of the mainly fault mode occurrence in early days , and each a fault mode to the sub- system or the whole machine effect and the function(make the sub- system or the whole function with a certain machine or make a certain function index sign descend),to personnel what safety and the surroundings environment etc. result in influence.Pass analysis the main fault reason have natural disaster(24.78%) and unqualified accessory(23.01%),assemble unreasonably (15.93%) and so on.3. the fault bane degree analysis in early days(FCA)The bane degree analysis is on a foundation of the FMEA, it is the the key step that fault influence the result fixed amount , its purpose is to research fault code according to each a fault the seriousness Class and the bane number of degrees word or occurrence of the mode all the comprehensive influence of the rate to study the fault mode, in order to evaluate influence of the fault mode completely.The bane degree of the parts is the bane degree that fault result to the parts to synthesize to assess, respond When the sub- system or the parts occurrence break down, to the influence degree of the whole function,effect,the surroundings environment and personnel safety.The analysis of the whole system bane degree can acquire a key parts of influence this detection system reliability, touching the weak link of the pure system, in order to have already carried on the reliability improvement design. This text first time got the automobile detection the bane degree of each sub- system of system is shown as follows:Four, this text combined with the analytical result of the early period fault, first time to the main fault part and fault mode of the automobile detection system to put forward the reliability improved suggestion in early days and from design,assembly,maintenance and accessory and so on. to put forward homologous of reliability promise measure.