Method for sensing automotive oil level and sensor

Abstract

The invention relates to a method for sensing an oil level of an automobile fuel tank, which adopts two parallel plate capacitors as a measurement capacitor and a reference compensation capacitor respectively; the height of the measurement capacitor is close to or equal to that of the fuel tank, and the measurement capacitor is vertically arranged in the fuel tank; and the reference compensation capacitor is horizontally arranged at the bottom of the fuel tank and immersed in oil liquid. The two capacitors are of an open type; when the oil-level height in the fuel tank changes, the height of oil liquid entering the measurement capacitor also changes and a capacitance value of the measurement capacitor changes correspondingly, but a capacitance value of the reference compensation capacitor does not change with the change of a liquid level. The measurement capacitor is compensated by the reference compensation capacitor, so an accurate change value of the measurement capacitor can be obtained; and an exact value of the oil-level height in the fuel tank can be acquired by the linear relation of the change value of the measurement capacitor and the oil liquid height through circuit processing so as to realize oil-level measurement. Due to the adoption of the reference compensation capacitor, the oil-level measurement which is irrelevant to media under different environments is realized; and the used sensor has corrosion resistance, no mechanical moving parts, long service life, simple structure, low process requirements and low cost.

Description

Technical field [0001] The invention relates to a liquid level height sensing technology, in particular to a sensing technology for the oil height of an automobile fuel tank. Background technique [0002] Automobile oil level sensors can be used to detect the amount of oil in the fuel tank, engine oil, and brake oil tank. When the engine oil is insufficient, the sensor detects this situation in time and immediately sends an electrical signal to the ECU. The ECU activates the warning system, illuminates the warning light or emits a warning sound, and prevents the engine from continuing to work under poor lubrication conditions, thus effectively Prevent engine damage; when the amount of fuel is insufficient, remind the driver to refuel to avoid the car from breaking down due to insufficient fuel; when the amount of brake oil is insufficient, the ECU activates the warning system, lights up the warning light or sounds a warning to prevent the car from braking Failure to work and oth...

AI Technical Summary

Problems solved by technology

[0015] Aiming at the respective advantages and disadvantages of the oil tank oil level sensors with different principles common in the market at present, the present invention proposes an oil level height position sensing method and sensor based on the principle of parallel plate capacitance without internal mechanical moving parts

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