基于角域同步平均技术的内燃机失火故障诊断

Internal Combustion Engine Misfire Fault Diagnosis Based on Angle-Domain Synchronic Average

在利用缸盖振动信号诊断内燃机失火故障时,由于发动机工作背景噪声复杂,必须消除信号中的非周期分量和随机干扰,保留与发动机工作循环有关的周期分量。为了解决时域同步平均方法在转速波动时振动信号存在的不同步问题,提出了以旋转角度信号作为同步触发基准的角域同步平均技术,对内燃机缸盖振动加速度信号进行了处理,有效地削弱了随机噪声的干扰。分析了缸盖振动信号中不同激励源产生的响应分量与发动机失火故障的关系,利用缸盖振动加速度信号中的各个瞬态冲击响应更加易于识别,能有效地对内燃机失火故障进行诊断。

It is necessary to eliminate noise component of signals while vibration signals of cylinder are used to diagnose misfire fault of internal combustion engine. In this paper, the technology of angle-domain synchronic average is presented to solve the synchronic problem of time-domain average,and the method is used to pretreat vibration signals of cylinder to decrease the influence of noise. The exciting source of cylinder vibration is analyzed. The transient responses in the vibration signals are applied to diagnose diesel misfire fault successfully.