Research On The Application Of BIT System Based On Fault Tree In Locomotive Electronic Control Cabinet Detection

Facing the drastic competition in the field of traffic, the railway department of our country advocates that railway transportation should develop towards the "safety, heavy loading and high speed", which gives big challenge to the reliability and security of locomotive operation. The electronic control cabinet (ECC) is an important component of electric locomotive. And it includes many circuit units, because these electronic equipment works under high temperature vibration condition for long, the fault ratio of the ECC is high, it needs a means to inspect state and diagnose fault online for the ECC, but it's very difficult to satisfy the request for the traditional diagnosis equipment. BIT technology is one of the most important means of fault diagnosis online nowadays, which applied widely in aviatic electronic equipment but applied rarely in other field. For solving actual problem, this paper associates advanced BIT technology with the ECC's fault diagnosis online, designs an ECC's BIT system based on fault tree experimentally and its idiographic realization project.Firstly, the thesis studies deeply the BIT technology's characteristic, the fault tree theory and the ECC's function, analyzes the types and reasons of ECC's fault and establishes mathematical models for some typical faults. After studying the choosing principia of electronic equipment BIT system test point, the thesis decides to choose the design project by BIT exterior test point.Secondly, the thesis designs BIT circuits for some function circuits based on reading a great deal of correlative literature at home and aboard., fault simulations are done for them with software of Multisim and the simulation results indicate that the BIT circuits can diagnose and insulate fault of the function circuits.Thirdly, the thesis studies all kinds of design request of electronic equipment BIT system and the signals which can be collected form ECC, applies ECC's exterior test channel (29# and 49# of A group and 29# of B group) as exterior test point of BIT system to design detailedly the ECC's BIT system. The BIT system includes three parts; there are BIT information acquisition module, BIT information processing module and a control computer. Thereinto two parts of the front are the most important units, which include the design of electrical source isolation circuit, all kinds of information acquisition circuit, the software and hardware of BIT information processing unit (DSP), and so on, establishes a software and hardware platform of ECC's BIT system. The thesis also studies the realizations of BIT system's three workings, which include electrify BIT, continuous BIT and manual BIT, and designs work flows for them.Finally, the thesis analyzes deeply the four work states of ECC and establishes their fault tree models, and elaborates the working and achievement process of fault isolation using fault tree arithmetic.The study of this thesis has a certain realistic guidance meaning for designing of electron equipment.