频率抽样滤波法处理发动机示功图的实验研究

Experimental study on processing indicator diagram based on frequency sampling filtering method

测量内燃示功图数据时由于缸压传感器与燃烧室之间存在连接通道而产生通道效应,测得的示功图出现锯齿形波动,严重影响后期的燃烧分析。根据通道效应主要影响缸压频谱的中频段的特点,设计了基于频率抽样法的滤波程序。该程序无需任何参数设置,由输入的缸内压力数据自动计算滤波器参数,实现了缸压数据的智能滤波。通过在发动机测试平台上实验,表明该算法稳定可靠,滤波后频谱变化小,保留了更多有用信息,可以很好的去除通道效应。

As there is a passage between the combustion chamber and cylinder pressure sensor,the in-cylinder pressure measured by that system will be affected by that passage,and seriously affecting the subsequent combustion analysis.Considering the passage effect mainly affecting the middle frequency band of in-cylinder pressure data,a filter algorithm was designed.The filter parameter calculation was based on in-cylinder pressure input without any parameter settings,and it can achieve the automatic data processing.After the experiment on the engine test platform,this program is proved to be reliable,has smaller change in frequency spectrum and could retain more useful information.The filter can remove the passage effect well.