Diesel Engine Misfire Fault Diagnosis Based on Instantaneous Speed

With the improvement of request in diesel engine dynamic performance, economical efficiency and emission behavior, test technology of diesel engine has gained extensive attention, which has become one of the hot points in the domestic and international relevant research fields. Among the performance parameters of diesel engine, the instantaneous speed signal contains relevant information about diesel engine combustion and working conditions. As researches show, the instantaneous speed can be used to detect the diesel engine cylinder compression pressure, working nonuniform, combustion difference and other working character. Therefore, the study of instantaneous speed has gradually become a significant technology of non-contact detection. In this paper, the algorithm of instantaneous speed signal is successfully realized under specific sampling frequency. Furthermore, the change law of instantaneous speed curve is compared under different rotate speed. At last, fuel supply of one cylinder is cut off to imitate the misfire fault of diesel engine, and then the fault is successfully diagnosed through the analysis of instantaneous speed. Thus, both the algorithm realization of instantaneous speed and the conclusion related to misfire fault diagnosis can be used to various kinds of diesel engines, which have important project application value.