利用缸盖振动信号检测发动机功率的试验研究

用发动机缸盖的振动信号进行了发动机功率检测试验。基于LabVIEW建立的虚拟仪器系统，运用加速度传感器测定了发动机从怠速急加速到高速过程中的缸盖振动信号，对发动机怠速段、高速段的振动信号进行了频谱分析，同时对比分析了低频振动信号与发动机转动时测得的脉冲信号。结果表明，发动机缸盖振动加速度信号中低频振动信号的周期与发动机转动周期有确定的对应关系，用低频振动信号峰值点可以分离出发动机的转速，从而可根据无负荷测功角加速度原理得出发动机不同转速下的有效功率值，因此利用发动机缸盖振动信号进行功率检测的方法是有效可行的。

Measurement of engine power using cylinder-head vibration signals

Engine power was detected using the cylinder-head vibration signal. Based on the virtual instrument system constructed by using LabVIEW, the cylinder-head vibration signals were detected with accelerometer while the engine was rapidly accelerated from idle speed to high speed, the spectral analysis of the idle and high speed section vibration signals was also made, then low-frequency vibration signal and the impulse signal measured in engine running state were compared and analyzed. The result shows that the low-frequency vibration signal cycle of cylinder-head vibration accelerating signal has a corresponding relationship with the rotation cycle of the engine. And the rotating speed of the engine can be separated from the peak value points of the low-frequency vibration signal, and then the virtual power values at different rotating speeds can be educed with the principle of angular acceleration measurement under unloaded conditions. Therefore the approach to detect engine power by means of cylinder-head vibration signal is proved to be both effective and feasible.