Design on Instantaneous Rotational Speed Measuring Device of Engine

The measuring of engine´s rotational speed uses frequency measuring and period frequency measuring methods at present time. But they can´t satisfy high degree of accuracy in the reality of project. A method of self-correction frequency measuring is proposed for this problem. This method overcomes measuring inaccuracy due to inherent lack of resolution in digit timer and solves the puzzle of high accuracy measuring at low rotational speed. The device of measuring rotational speed is manufactured, and CAN network interface is designed. The whole measuring device can realize long distance and real time acquisition of engine´s rotational speed and also control parameters distribution. The result of assay verifies the method is correct and effective.