Research on measurement of engine speed base on LabWindows/CVI

Engine speed is a very important reference signal in the fault diagnosis of the engine. This paper discussed a method to measure the engine speed by analyzing the engine cylinder vibration signal, based on the software of LabWindows/CVI. We can get the speed of the engine after the fowling steps: firstly, sample the vibration signal produced by the burning gas in engine cylinder; and then using the software of LabWindows/CVI to process the signal by frequency spectrum analysis and low-pass filter; finally, combining the vibration source and the relationship between engine vibration and engine speed. The experiment result indicates that this engine speed measurement method shows a high precision.