Plane capacitance sensor and method for detecting environmental change of motorcar glass

Abstract

A kind of flat capacitance-type sensor includes a flat capacitor, a flat capacitance compensator which eliminate interfere signal and a sensor detecting circuit. The invention adopts double-flat capacitance, thereinto one is used as measuring capacitance; another is as compensating capacitance, it is insensitive with rain water of outer surface by changing mounting position and shape of compensating capacitance, and sensitive with temperature shift and electromagnetic interfere. When there is temperature shift or electromagnetic interfere, the value of measuring capacitance and compensating capacitance change at the same time and extent are similar, when rain water is changed, value of measuring capacitance changes, but value of compensating capacitance does not change. Using characters above can difference compensate measuring of sensor, disadvantageous affects of temperature shift and electromagnetic interfere can be decreased, error action of rain shaving can be avoided.

Description

Technical field: [0001] The invention relates to a device for detecting environmental changes of the windshield of an automobile, in particular to a detection device for detecting changes in the amount of rain on the windshield of an automobile and a detection method using the detection device. Background technique: [0002] Since entering the 21st century, automobile electronics and intelligence have become the direction and frontier of the development of automobile industry technology, and the safety and humanization of automobiles have also become the focus of major automobile manufacturers. The automatic detection system not only focuses on humanized care for driving convenience, but more importantly, the automatic detection system is an important part of the vehicle's active safety system. In rainy days or in environments with high relative air humidity, the windshield surface of a car often affects the driver's sight due to excessive rain. [0003] The key technology ...

AI Technical Summary

Problems solved by technology

[0019] One of the technical problems to be solved by the present invention is to overcome the deficiencies of the above-mentioned prior art and provide a planar capacitive sensor capable of eliminating temperature drift and electromagnetic interference. The traditional detection device has the disadvantages of small measurement area, inability to measure the thickness of rainwater, easy to be interfered by pollutants, high installation requirements, poor adaptability and high cost, etc.

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