确定精确的诊断阈值是故障诊断工作中的重要环节。为减少内燃机故障诊断中的漏诊或误诊现象,通过内燃机失火、死火工史下各缸峰值压力数据分析,针对各缸工作的不均匀性,提出了基于单缸峰值压力的3σ阈值制定法和基于单缸峰值压力偏差的阈值制定法。试验结果表明,这2种方法制定的阈值能准确地诊断出内燃机气缸的故障。
Determining the precise diagnosis threshold is an important link of fault diagnosis. In order to reduce missed or delayed diagnosis in internal combustion engine fault diagnosis, through data analysis of each cylinder peak pressure under the condition of internal combustion engine misfire and dead fire, aiming at the non-uniformity in the management of each cylinder, the 3σ threshold statute based on single cylinder peak pressure and threshold value defining method based on single cylinder peak pressure deviation are proposed. Experimental results show that the threshold set by both methods can accurately diagnose the fault of internal combustion engine cylinder.