利用转速波动信号诊断内燃机失火故障的研究(2)——波形分析方法

Misfire Detection for Internal Combustion Engines by Speed Fluctuation Signals ——Part Ⅱ:Method of Waveform Analysis

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)。本文介绍了第 2种方法——波形分析方法。通过深入分析瞬时角加速度和瞬时转速信号的波形特点 ,直接定义了 6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。试验结果表明 ,这 6种特征参数都与内燃机工况和结构参数无关 。

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,the relationship among the instantaneous angular acceleration,the instantaneous angular velocity and the gas pressure torque is illustrated.Six dimensionless parameters are defined for misfire detection.These parameters are extracted directly from the angular acceleration and velocity waveform,and have nothing to do with the engine structure and operating conditions.Experimental results show that this technique has the capability of identifying the position of a misfiring cylinder or cylinders with efficient and simple computations.