Device and method for measuring rotation angle of engine crankshaft

Abstract

The invention discloses a device for measuring the rotation angle of an engine crankshaft, which comprises an encoding disk, a photoelectric sensor, a signal collector and a signal processor, wherein the encoding disk rotates along with the engine crankshaft and produces optical pulse signals; the photoelectric sensor is used for sensing the optical pulse signals which are produced during the rotation process of the encoding disk along with the engine crankshaft and converting the optical pulse signals to electric pulse signals; the signal collector is used for collecting the number of high and / or low level pulses of the electric pulse signals; and the signal processor is used for obtaining the rotation angle of the engine crankshaft according to the number of high and / or low level pulses. The invention can provide the high-precision measurement of the rotation angle of the engine crankshaft. The invention further discloses a method for measuring the rotation angle of the engine crankshaft.

Description

technical field [0001] The invention relates to measurement technology, in particular to a measurement device and method for engine crank angle. Background technique [0002] With the development of automobile technology and the improvement of national emission standards, the requirements for engine control are getting higher and higher. To achieve precise control of the engine, it is first necessary to achieve accurate measurement and collection of various engine data. Among the many data of the engine, its crankshaft angle is an important data. [0003] The crankshaft angle of the engine is determined by the angles corresponding to the different positions passed by the crankshaft during one revolution, and the corresponding piston position is obtained through the crankshaft angle, thereby determining the ignition time of the engine. Whether the ignition time of the engine is correct is directly related to the power output of the engine and the combustion of fuel (whether ...

AI Technical Summary

Problems solved by technology

The main hazards caused by the incorrect ignition time of the engine are: 1. Too early ignition time of the engine will cause knocking, which will damage the engine or reduce its life

2. If the ignition time of the engine is too late, the fuel will be exhausted due to insufficient combustion, causing air pollution, so that the emission is seriously not up to standard

3. Whether the ignition time of the engine is advanced or too late, the power output of the engine will be insufficient

[0005] However, the existing electromagnetic sensors have the following disadvantages: (1) the number of teeth of the tooth disc is small, and the accuracy of the sensor is low; The peak value of the voltage signal varies greatly, and the approximate waveform is compared to image 3 shown

As shown in the figure, the voltage at low speed is very small (generally only a few volts), and at high speed the voltage is very large (can reach tens of volts), so the voltage impact on the chip processing the signal is very large, causing damage to the chip (3) In the process of square wave conversion, the pulse width of the square wave will be different due to the difference in the amplitude of the sensor with the speed of the speed, resulting in errors, resulting in a large test error generated by this type of sensor ; (4) The installation requirements of this type of sensor are relatively high, mainly referring to the fact that the relative position of the gear plate and the electromagnetic induction element must be the same, otherwise the error of the generated waveform will be greater

[0006] Therefore, the engine crank angle measurement device of the prior art cannot provide accurate rotation angle measurement

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