And then the applications of some general oil monitoring methods including physical chemistry analysis , ferrograph analysis , contamination degree analysis , etc , in fault diagnosis of diesel engine are analyzed , and also the relations between those methods and diesel engine ' s fault modules are discussed 然后分析了几种常用的油液分析方法在柴油机故障诊断中的应用，包括理化分析、铁谱分析、污染度分析等，及各分析方法与各故障模式的关系。
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 并在此基础上，研究、提出和实现了以下几种方法：提出了应用局域波时频谱和局域波边界谱对柴油机进行状态监测和故障诊断的新思路，解决了柴油机故障诊断中的一些实际困难。
According to the current situation and developing trend of domestic and foreign diesel engine fault diagnosis , combined with the need of practical project , the diesel engine fault diagnosis based on crankshaft instantaneous angular acceleration is carried out ; principles and feasibility of this method are studied theoretically 经过了解国内外柴油机故障诊断的现状和发展趋势,结合实际项目的需要,提出了使用发动机曲轴角加速度信号来进行故障诊断。从理论上详细研究了这一柴油机故障诊断方法的原理和可行性,文中指出了这种方法的优缺点和适用范围。
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 dimensions n 研究了利用分形技术对柴油机进行故障诊断的一般过程，提出了局域波分形分析方法，即利用局域波分解后的各基本模式分量的关联维数的大小及变化，来刻画系统工作状态，并成功的应用于柴油机故障诊断中。
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 接着，通过对柴油机表面振动信号的长期进行测试、分析、诊断及经验的积累，提出了一种实用型气缸压力识别的方法，并作了简单理论验证，该方法在柴油机故障诊断中起到了积极的作用。
