The application discloses a
diesel engine under-charge real-time monitoring and fault diagnosis method, which measures the parameters such as
cylinder pressure and
crank angle signals of the
diesel engine by comprehensively applying various sensors, firstly reads or calculates the
cylinder pressure at the
top dead center, the maximum explosion pressure, the
effective power feature and the average effective pressure, respectively, calculates the difference value of the above parameters and the threshold value of the corresponding normal working condition, respectively, and preliminarily diagnoses whether the
diesel engine is under-charge; secondly, the fault degree of each parameter is judged by calculating the deviation rate of each parameter; finally, the overall fault degree is comprehensively analyzed according to the above fault degree; according to the fusion of the fault characteristic information, the typical fault characteristics are compared, so that the composite fault diagnosis of the diesel engine is realized, various characteristic information is fully utilized, the diagnosis speed and accuracy are improved, qualitative and quantitative analysis is realized, and the application of the diesel engine fault diagnosis level will be improved.