利用转速波动信号诊断内燃机失火故障的研究(1)——诊断模型方法

Misfire Detection for Internal Combustion Engines by Speed Fluctuation Signals ——Part Ⅰ:Method of Diagnostic Model

提出了利用转速波动信号诊断内燃机失火故障的 3种方法 ,包括诊断模型方法 (1 )、波形分析方法(2 )和多特征综合方法 (3)。本文介绍了诊断模型方法。通过分析曲轴飞轮系统的动力学特性 ,建立了简明实用的瞬时转速诊断模型 ,揭示了瞬时转速波动信号与气体力扭矩及各缸气体压力之间的本质联系 ;进而将模型方程转换到频域内处理 ,定义了 4种诊断失火故障的无量纲特征参数 ,给出了这些参数的快速提取算法和故障识别方法。最后通过试验研究 。

Three methods have been developed for misfire detection in internal combustion engines by speed fluctuation signals.They are based on a diagnostic model,waveform analysis and multiple feature integration,respectively.The whole paper is divided into three parts.In this part,a simplified diagnostic model relating the gas pressure torque to the crankshaft speed fluctuations is derived.By analyzing and processing the model equation in the angular frequency domain,four dimensionless features are defined for misfire detection.The fast algorithm for extracting such features and the misfire identification approach are put forward.Experimental results in real world engines are presented,proving the technique to be efficient and simple in implementation.