Abstract: Considering the situation of rotational speed changing and space limitation, a smart online monitoring system for diesel engine is designed. After sampling the signal of magnetoelectricity speed sensor, the instantaneous speed signal of the diesel engine is analyzed. Corresponding parameters are computed to estimate the fault of the diesel engine. After analyzing the parameters of 120 swatch samples in normal condition, one cylinder misfire and two cylinder misfire working conditions when the engine operates at low speed, middle speed, accelerating and high speed, it is shown that these working conditions can be distinguished effectively using these parameters. Corresponding thresholds of the parameters are also indicated to estimate the cylinder-to-cylinder uniformity.

Key words: vibration and wave, fault diagnosis, diesel, instantaneous rotational speed, online monitoring, DSP

摘要： 针对柴油机实车在线监测中车内空间有限及变速的情况，设计基于嵌入式系统的柴油机智能监测节点。利用整形后的外卡式油压传感器信号产生中断，来对磁电式转速传感器进行工作周期采样。对不同工况、不同转速情况下瞬时转速信号的变化规律进行分析。对各缸提取相应的参数来判断柴油机各缸工作不均匀性故障。在对正常、一缸失火及两缸失火工况，在惰速、中速、加速及高速下采集的120组参数进行分析后，证实提取的参数能有效的区分这些工况。对参数指定相应的阈值实现对各缸工作均匀性的定性、定量及定缸判断。

关键词: 振动与波, 故障诊断, 柴油机, 瞬时转速, 在线监测, DSP