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CN-115951426-B - Rain and fog sensor, laminated glass and automobile

CN115951426BCN 115951426 BCN115951426 BCN 115951426BCN-115951426-B

Abstract

The invention relates to a rain and fog sensor, laminated glass and an automobile, wherein the rain and fog sensor comprises a capacitance digital conversion circuit, a switch array and an FPC board, at least three mutually insulated rain detection electrodes are arranged on the front surface of the FPC board, at least two independent mutually insulated fog detection electrodes are arranged on the back surface of the FPC board, the coverage area of each rain detection electrode is larger than that of each fog detection electrode, each fog detection electrode is covered by the normal projection of the rain detection electrode on the FPC board, each rain detection electrode is electrically connected with the capacitance digital conversion circuit and the ground through the switch array in a time-sharing gating mode, and each fog detection electrode is electrically connected with the capacitance digital conversion circuit.

Inventors

  • SUN TENGCHEN
  • JIANG HUA
  • WANG KAI

Assignees

  • 北京他山科技有限公司

Dates

Publication Date
20260512
Application Date
20221219

Claims (10)

  1. 1. A rain and fog sensor, characterized in that: the rain and fog sensor comprises a capacitance-to-digital conversion circuit, a switch array and an FPC board; At least three mutually insulated rainfall detection electrodes are arranged on the front surface of the FPC board, at least two independent mutually insulated rainfall detection electrodes are arranged on the back surface of the FPC board, The coverage area of the rainfall detection electrode is larger than that of the fog detection electrode, and each fog detection electrode is covered by the normal projection of the rainfall detection electrode on the FPC board; each rainfall detection electrode is electrically connected with the capacitance-to-digital conversion circuit and the ground respectively through a switch array in a time-sharing gating manner, and each fog detection electrode is electrically connected with the capacitance-to-digital conversion circuit.
  2. 2. The rain and fog sensor of claim 1, wherein: Each rainfall detection electrode is symmetrically arranged and forms at least 2 pairs of symmetrical electrodes or symmetrical electrode groups, wherein the symmetrical areas, shapes and intervals of each pair of symmetrical electrodes or symmetrical electrode groups are equal; The capacitance-to-digital conversion circuit can acquire the mutual capacitance of each pair of symmetrical electrodes or symmetrical electrode groups and/or the self capacitance of each rainfall detection electrode through the switch array.
  3. 3. The rain and fog sensor of claim 2, wherein: The fog amount detection electrodes are paired to form an electrode unit, and two fog amount detection electrodes in the electrode unit are configured to be formed in a curve shape with parallel wires at certain intervals on the same plane; The electrode units are at least two, each electrode unit is symmetrically arranged and forms at least 1 pair of symmetrical electrode units or symmetrical electrode unit groups, and the symmetrical areas, the symmetrical shapes and the symmetrical spacing of each pair of symmetrical electrode units or symmetrical electrode unit groups are equal; the capacitance-to-digital conversion circuit can acquire the mutual capacitance between the two fog detection electrodes in each electrode unit through the switch array.
  4. 4. A rain and fog sensor according to claim 3 wherein: The capacitance-to-digital conversion circuit also obtains differential capacitance formed by three rainfall detection electrodes or three rainfall detection electrode groups through a switch array and/or The number of the electrode units is greater than or equal to three, and the capacitance-digital conversion circuit also obtains differential capacitance formed by the three electrode units or the three electrode unit groups through the switch array.
  5. 5. A rain and fog sensor according to claim 3 wherein: The symmetry point of each fog detection electrode and the symmetry point of each rainfall detection electrode are positioned on the same normal line of the FPC board; the capacitance-digital conversion circuit is arranged on the normal line, and electrode leads between the fog quantity detection electrode and the rainfall detection electrode and the capacitance-digital conversion circuit are symmetrically arranged.
  6. 6. The rain and fog sensor of claim 1, further comprising a master control circuit, wherein the capacitance-to-digital conversion circuit is electrically connected to the master control circuit.
  7. 7. The rain and fog sensor of claim 6, wherein at least two of the capacitance-to-digital conversion circuit, the master control circuit, and the switch array are configured to be integrated with an R-SPINNAKER chip.
  8. 8. The rain and fog sensor of claim 1, wherein: Detecting the capacitance value of the fog amount detection electrode and the rain amount detection electrode in a time-sharing manner; and controlling each rainfall detection electrode to be grounded and shielded when the capacitance value of the fog detection electrode is detected, and correcting the detection data of the rainfall detection electrode by using the detection data of the fog detection electrode when the capacitance value of the rainfall detection electrode is detected.
  9. 9. A laminated glass having an outer glass and an inner glass, wherein the laminated glass comprises the rain sensor according to any one of claims 1 to 8, and each of the rain detection electrodes is disposed between the outer glass and the inner glass.
  10. 10. An automobile comprising the laminated glass according to claim 9.

Description

Rain and fog sensor, laminated glass and automobile Technical Field The invention relates to a rain and fog sensor which is suitable for detecting rain and fog on laminated glass such as automobile front windshield glass, skylight glass and the like. Background Traditional rain and fog sensor for detecting rain and fog on front windshield glass of automobile is arranged in front windshield glass, and needs to be provided with components such as sensor film, sensor support, sensor base, etc., and has the problems of cost of sensor shell, support and base and vision shielding. In order to improve the above problems and solve the mutual interference of rain and fog detection of the patent of the invention with the application number 201780003059.8 and the interference of rain and fog on the back surface of the front windshield glass caused by fog generation in heavy rainy days, the ideas of arranging a shielding electrode by clamping a detection electrode between the inner layer and the outer layer of the front windshield glass of the automobile are proposed by CN201811301137.5 and CN 201811301102.1. The rain amount detection electrode and the fog amount detection electrode are required to be arranged, and the shielding electrode is required to be arranged on the back surface of the rain amount detection electrode and the front surface of the fog amount detection electrode, so that the defect that the arrangement space requirement of the sensor electrode is large exists, in other words, the shielding electrode provided for solving the interference inevitably causes the increase of the arrangement space of the sensor electrode, and the requirements of integrating and intelligently controlling the sensor to set up other sensors in the front windshield glass area as much as possible conflict. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide a rain and fog sensor, laminated glass using the rain and fog sensor and an automobile. The rain and fog sensor comprises a capacitance-to-digital conversion circuit, a switch array and an FPC board, wherein at least three mutually insulated rain detection electrodes are arranged on the front surface of the FPC board, at least two independent mutually insulated fog detection electrodes are arranged on the back surface of the FPC board, the coverage area of each rain detection electrode is larger than that of each fog detection electrode, each fog detection electrode is covered by the normal projection of the rain detection electrode on the FPC board, each rain detection electrode is electrically connected with the capacitance-to-digital conversion circuit and the ground through the switch array in a time-sharing gating mode, and each fog detection electrode is electrically connected with the capacitance-to-digital conversion circuit. In the detection process, the capacitance values of the fog detection electrode and the rain detection electrode are detected in a time-sharing manner, when the capacitance value of the fog detection electrode is detected, the grounding shielding of each rain detection electrode is controlled, when the capacitance value of the rain detection electrode is detected, the detection data of the rain detection electrode are corrected by using the detection data of the fog detection electrode, the interference of rain on fog detection and the interference of fog on rain detection can be solved, meanwhile, the rain detection electrode is multiplexed to make both rain detection and fog detection electrode shielding, the requirements of high space utilization and small volume are met, and space is reserved for installing other sensors in a front windshield area. Further, the rain amount detection electrodes are symmetrically arranged to form at least 2 pairs of symmetrical electrodes or symmetrical electrode groups, wherein the symmetrical areas, the symmetrical shapes and the symmetrical distances of the symmetrical electrodes or the symmetrical electrode groups are equal, and the capacitance-digital conversion circuit can acquire the mutual capacitance of each pair of symmetrical electrodes or the symmetrical electrode groups and/or the self capacitance of each rain amount detection electrode through the switch array. Under the hardware structure, the program can adopt periodic time-sharing measurement, taking three electrodes as an example, one measurement period T can be divided into 6 measurement periods T1, T2 and..T6, wherein three mutual capacitances are measured in the periods T1, T2 and T3, and three self capacitances are measured in the periods T4, T5 and T6. The mutual capacitance of each pair of symmetrical electrodes or the symmetrical electrode groups and/or the self capacitance of each rainfall detection electrode are/is transmitted to a processing system such as a main control circuit through the symmetrical rain sensor, firstly, the rainfall data are discrete asymmetric data and the temperatur