| In recent years, the technique of mechanical fault diagnosis, which plays important role in national manufacture, is quickly developed in domestic and oversea, and is deeply implied in many fields. It is momentous signification to diagnose faults because diesel engines have special use. In this paper, in order to solve practice problem, characteristic information for faults is gained from diesel engine vibration signal by using new method adapting to analyze non-stationary signal on the basis of former achievements, and valid results are obtained.First, from the starting point of vibration signals formed, the characteristics of actuation sources and their responses and the relations between them are discussed in detail. Meanwhile, radiate routes of vibration signals are analyzed, and pretreatment methods for vibration signals are presented. The results show that it is effective and feasible to diagnose faults of diesel engine by mean of un-disassembly using surface vibration signal..Then, local-wave (LW) method is imported especially for solving questions about nonlinear and non-stationary of diesel surface vibration signals. The main innovations embodied in this method are the introduction of the intrinsic mode functions based on local properties of signals, which make the instantaneous frequency meaningful. Using this method validly overcome disadvantages caused by using traditional methods, which eliminate the need for spurious harmonics to represent nonlinear and non-stationary signals. In addition, complicated tested data are decomposed into several intrinsic mode functions by this way. which low analyzing error, and predigest processing. On the basis of it, several new methods is studied , put forward and realized.The way is put forward for diesel engine condition monitoring and fault diagnosis using local-wave time-frequency approach and boundary-spectrum. The advantages of local time-frequency are displayed by contrasting with others of time-frequency approaches. Using this way validly overcame disadvantages caused by using other methods, which can not get all of over information about working condition of diesel engine, and it is demonstrated on experimental data for piston-liner wear. At last, the validity and the superiority of boundary-spectrum are improved by contrasting with power spectrum density (PSD) to analyze tested data.Local-wave method uniting with time series analysis is important significance to solve complex questions caused by the system of diesel engine. It is known that each intrinsic mode function has special character, so LW-AR spectrum method is submit for practice application. At the same time, the new approach based on LW and K-L information is introduced in order to identify style and degree of diesel faults, and is implied in faults diagnosis flexibly.LW fractal method is firstly point out for diesel fault diagnosis. It also said that correlation dimensions of intrinsic mode functions are calculated to delineate and detect working conditions of diesel engine. The conclusion is gained that the correlation dimensionsn?under similar working condition have similar value while different working condition have different value, so the correlation dimension can usefully reflect working conditions. This way promote the technique about condition monitoring and fault diagnosis of diesel engine into further step.In succession, through testing, analyzing, diagnosing to diesel surface vibration signals for long time and experience piling up, a new practicability way for identifying cylinder pressure is discovered, and validated in brief. Meanwhile, the experimental results confirm the validity and practicability of this way.At last, aiming at some problems about moving machinery now, such as the backward manage, the difficult to check performances, the high of maintenance expenses, it takes performance checking for moving machinery in Xianglujiao corporation of Dalian Port as background, the author develops 'Fault diagnosis and predicting maintenance system for...
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