A capacitive contact-type displacement measurement sensor and sensing system

Abstract

The invention provides a capacitive contact-type displacement measurement sensor and sensing system. The sensor comprises a fixed part and a moving part. The fixed part comprises a fixed insulation substrate and a capacitance electrode piece group fixed on the fixed insulation substrate, wherein the capacitance electrode piece group comprises conductive electrode pieces and fixed side thin film covering each conductive electrode piece. The moving part comprises a moving insulation substrate and a grounding electrode piece group located on the moving insulation substrate, wherein the grounding electrode piece group comprises conductive electrode pieces and moving side thin film covering each conductive electrode piece; the fixed part and the moving part are arranged to be opposite each other in a Z direction perpendicular to an X direction and the moving part and the fixed part are in contact-type sliding fit connection in the X direction so that the moving side thin film and the fixed side thin film can maintain zero clearance in the Z direction; the capacitance electrode piece group and the grounding electrode piece group can form a variable capacitor in a moving process. The sensor has the advantage that there is no need to perform compensation design for clearance changes, so that the structure can be simplified and the performance of the sensor can be improved.

Description

technical field [0001] The invention relates to a capacitive sensor, in particular to a capacitive contact type displacement measurement sensor for measuring displacement based on changes in the facing area of ​​a capacitive pole piece, and a sensing system based on the sensor. Background technique [0002] The sensor device that uses the capacitance change of the parallel plate capacitor to measure the displacement has been widely used. There are two main methods to measure the displacement by the capacitance change: one is the displacement sensor of the gap change type, and the other is the area change type. capacitive sensor. [0003] The problem of the above-mentioned capacitive displacement sensor with area change is that it is difficult to avoid the influence of the gap change on the displacement measurement accuracy when measuring the displacement, and the effect of the gap change on the capacitance of the capacitor is very sensitive, such as in In a capacitor with a...

AI Technical Summary

Problems solved by technology

[0003] The problem of the above-mentioned capacitive displacement sensor with area change is that it is difficult to avoid the influence of the gap change on the displacement measurement accuracy when measuring the displacement, and the effect of the gap change on the capacitance of the capacitor is very sensitive, such as in In a capacitor with a gap of 100μm, a change of 1μm will cause a change of 1% in capacitance, and for most applications, an uncertainty error of 1% is unacceptable

In order to solve this technical problem, the solution that has been studied is to reduce the impact of gap changes on the displacement measurement accuracy by constructing variable capacitors that can form mutual compensation. It is not conducive to improving other performance of the sensor, such as improving resolution, increasing range, realizing absolute displacement measurement, etc., which will limit the scope of application of the sensor

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