CN100571035C - The method of plane capacitance sensor and the environmental change of detection windshield - Google Patents
The method of plane capacitance sensor and the environmental change of detection windshield Download PDFInfo
- Publication number
- CN100571035C CN100571035C CN 200610083392 CN200610083392A CN100571035C CN 100571035 C CN100571035 C CN 100571035C CN 200610083392 CN200610083392 CN 200610083392 CN 200610083392 A CN200610083392 A CN 200610083392A CN 100571035 C CN100571035 C CN 100571035C
- Authority
- CN
- China
- Prior art keywords
- planar capacitor
- signal
- plane capacitance
- compensator
- plane
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 230000008859 change Effects 0.000 title claims abstract description 42
- 238000001514 detection method Methods 0.000 title claims abstract description 33
- 238000000034 method Methods 0.000 title claims description 22
- 230000007613 environmental effect Effects 0.000 title claims description 9
- 239000003990 capacitor Substances 0.000 claims abstract description 145
- 239000011521 glass Substances 0.000 claims abstract description 81
- 238000012360 testing method Methods 0.000 claims description 44
- 238000006243 chemical reaction Methods 0.000 claims description 12
- 238000012545 processing Methods 0.000 claims description 12
- 238000001914 filtration Methods 0.000 claims description 8
- 239000010410 layer Substances 0.000 claims description 8
- 239000004033 plastic Substances 0.000 claims description 8
- 229920003023 plastic Polymers 0.000 claims description 8
- 230000008569 process Effects 0.000 claims description 8
- 239000004020 conductor Substances 0.000 claims description 7
- 239000011229 interlayer Substances 0.000 claims description 6
- 230000003068 static effect Effects 0.000 claims description 6
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 5
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims description 3
- 239000004411 aluminium Substances 0.000 claims description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 3
- 229910052782 aluminium Inorganic materials 0.000 claims description 3
- 230000005540 biological transmission Effects 0.000 claims description 3
- 239000010949 copper Substances 0.000 claims description 3
- 229910052802 copper Inorganic materials 0.000 claims description 3
- 239000012774 insulation material Substances 0.000 claims description 3
- 239000004332 silver Substances 0.000 claims description 3
- 229910052709 silver Inorganic materials 0.000 claims description 3
- 230000008030 elimination Effects 0.000 claims description 2
- 238000003379 elimination reaction Methods 0.000 claims description 2
- 238000005259 measurement Methods 0.000 abstract description 16
- 230000000694 effects Effects 0.000 abstract description 14
- 238000009434 installation Methods 0.000 abstract description 14
- 230000035945 sensitivity Effects 0.000 abstract description 10
- 230000002411 adverse Effects 0.000 abstract description 3
- 239000000463 material Substances 0.000 description 12
- 230000005684 electric field Effects 0.000 description 11
- 238000010586 diagram Methods 0.000 description 10
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 9
- 238000005516 engineering process Methods 0.000 description 8
- 239000003344 environmental pollutant Substances 0.000 description 6
- 230000008447 perception Effects 0.000 description 6
- 231100000719 pollutant Toxicity 0.000 description 6
- 230000002950 deficient Effects 0.000 description 5
- 230000008901 benefit Effects 0.000 description 4
- 238000007747 plating Methods 0.000 description 3
- 230000001681 protective effect Effects 0.000 description 3
- 230000006978 adaptation Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000004422 calculation algorithm Methods 0.000 description 2
- 239000011889 copper foil Substances 0.000 description 2
- 230000008878 coupling Effects 0.000 description 2
- 238000010168 coupling process Methods 0.000 description 2
- 238000005859 coupling reaction Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 230000007812 deficiency Effects 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 230000004043 responsiveness Effects 0.000 description 2
- 238000005507 spraying Methods 0.000 description 2
- 241000256626 Pterygota <winged insects> Species 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 239000005030 aluminium foil Substances 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 238000002788 crimping Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- -1 dirt Substances 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000005290 field theory Methods 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 230000003534 oscillatory effect Effects 0.000 description 1
- 239000002985 plastic film Substances 0.000 description 1
- 229920006255 plastic film Polymers 0.000 description 1
- 238000002310 reflectometry Methods 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60S—SERVICING, CLEANING, REPAIRING, SUPPORTING, LIFTING, OR MANOEUVRING OF VEHICLES, NOT OTHERWISE PROVIDED FOR
- B60S1/00—Cleaning of vehicles
- B60S1/02—Cleaning windscreens, windows or optical devices
- B60S1/04—Wipers or the like, e.g. scrapers
- B60S1/06—Wipers or the like, e.g. scrapers characterised by the drive
- B60S1/08—Wipers or the like, e.g. scrapers characterised by the drive electrically driven
- B60S1/0818—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like
- B60S1/0822—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like characterized by the arrangement or type of detection means
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60S—SERVICING, CLEANING, REPAIRING, SUPPORTING, LIFTING, OR MANOEUVRING OF VEHICLES, NOT OTHERWISE PROVIDED FOR
- B60S1/00—Cleaning of vehicles
- B60S1/02—Cleaning windscreens, windows or optical devices
- B60S1/04—Wipers or the like, e.g. scrapers
- B60S1/06—Wipers or the like, e.g. scrapers characterised by the drive
- B60S1/08—Wipers or the like, e.g. scrapers characterised by the drive electrically driven
- B60S1/0818—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like
- B60S1/0822—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like characterized by the arrangement or type of detection means
- B60S1/0825—Capacitive rain sensor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60S—SERVICING, CLEANING, REPAIRING, SUPPORTING, LIFTING, OR MANOEUVRING OF VEHICLES, NOT OTHERWISE PROVIDED FOR
- B60S1/00—Cleaning of vehicles
- B60S1/02—Cleaning windscreens, windows or optical devices
- B60S1/04—Wipers or the like, e.g. scrapers
- B60S1/06—Wipers or the like, e.g. scrapers characterised by the drive
- B60S1/08—Wipers or the like, e.g. scrapers characterised by the drive electrically driven
- B60S1/0818—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like
- B60S1/0822—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like characterized by the arrangement or type of detection means
- B60S1/0874—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like characterized by the arrangement or type of detection means characterized by the position of the sensor on the windshield
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60S—SERVICING, CLEANING, REPAIRING, SUPPORTING, LIFTING, OR MANOEUVRING OF VEHICLES, NOT OTHERWISE PROVIDED FOR
- B60S1/00—Cleaning of vehicles
- B60S1/02—Cleaning windscreens, windows or optical devices
- B60S1/04—Wipers or the like, e.g. scrapers
- B60S1/06—Wipers or the like, e.g. scrapers characterised by the drive
- B60S1/08—Wipers or the like, e.g. scrapers characterised by the drive electrically driven
- B60S1/0818—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like
- B60S1/0822—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like characterized by the arrangement or type of detection means
- B60S1/0874—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like characterized by the arrangement or type of detection means characterized by the position of the sensor on the windshield
- B60S1/0877—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like characterized by the arrangement or type of detection means characterized by the position of the sensor on the windshield at least part of the sensor being positioned between layers of the windshield
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60S—SERVICING, CLEANING, REPAIRING, SUPPORTING, LIFTING, OR MANOEUVRING OF VEHICLES, NOT OTHERWISE PROVIDED FOR
- B60S1/00—Cleaning of vehicles
- B60S1/02—Cleaning windscreens, windows or optical devices
- B60S1/04—Wipers or the like, e.g. scrapers
- B60S1/06—Wipers or the like, e.g. scrapers characterised by the drive
- B60S1/08—Wipers or the like, e.g. scrapers characterised by the drive electrically driven
- B60S1/0818—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like
- B60S1/0822—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like characterized by the arrangement or type of detection means
- B60S1/0874—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like characterized by the arrangement or type of detection means characterized by the position of the sensor on the windshield
- B60S1/0881—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like characterized by the arrangement or type of detection means characterized by the position of the sensor on the windshield characterized by the attachment means on the windshield
Abstract
A kind of plane capacitance sensor comprises that a planar capacitor, eliminates the plane capacitance compensator and a sensor detection circuit of interference signal.The present invention adopts biplane electric capacity, and one of them plane capacitance is as measuring electric capacity, and another is electric capacity by way of compensation, makes its rainwater to glass outer surface insensitive by installation site and the shape that changes building-out capacitor, and temperature is floated and the electromagnetic interference sensitivity.When meeting that temperature is floated or during electromagnetic interference, the measured value of measuring electric capacity and building-out capacitor takes place to change simultaneously and the amplitude of variation approximately equal simultaneously, measure capacitance when rainwater changes and change thereupon when meeting, and the building-out capacitor value remains unchanged substantially.Utilize above characteristic to carry out the difference compensation, reduce temperature effectively and float and the electromagnetic interference adverse effect that sensitivity brings to sensor measurement, avoid the windscreen wiper misoperation measurement value sensor.
Description
Technical field:
The present invention relates to a kind of device that detects the windshield environmental change, especially relate to checkout gear that detects the variation of windshield rainfall and the detection method that adopts this checkout gear.
Background technology:
Entered since 21 century, automotive electronicsization and intelligent direction and the forward position that has become the auto industry technical development, the fail safe of automobile and hommization also become the focus that each big automobile vendor pays attention to.Automatic checkout system is not only the concern with humanization that is conceived to conveniently driving, and the more important thing is that automatic checkout system is the important component part of automobile active safety system.Under the big environment of rainy day or relative air humidity, usually can influence driver's sight line on the windshield surface because of rainwater is excessive.
The key technology of automatic Wiper system of the prior art is the Raindrop sensor technology, to be objective, by the end of today, worldwide Raindrop sensor technology is still very unripe, although automobile vendor that some are famous such as germany volkswagen, U.S.'s Chrysler, french citroen etc. successfully have been equipped with automatic Wiper system on their automobile product, because Raindrop sensor technology immature caused sorry that installation difficulty is big, cost is high, the misoperation rate is higher.
Existing raindrop sensing technology can be divided into internally-arranged type and externally positioned type two big classes by installation form, externally positioned type is transducer to be installed in windshield is looked like above the hood outward, face outside, windshield outer surface etc. before the automobile, the feature of externally positioned type raindrop sensing is rainwater to be done direct contact type measure, and known externally positioned type Raindrop sensor is divided by operation principle photoelectric type, conductance type, oscillatory type and parallel-plate condenser type.Most externally positioned type Raindrop sensors are owing to can't be directly installed in the moving scope of glass outer surface rain brush brush, thereby can only the perception rainfall size and can't the moving effect of perception rain brush brush, thereby can only form open-loop control system to rain brush, can't form the closed-loop control system that can feed back the moving effect of rain brush brush.In addition, defectives such as the externally positioned type Raindrop sensor is contaminated easily in addition, damage, therefore, the externally positioned type Raindrop sensor seldom is applied in auto industry.The internally-arranged type Raindrop sensor is installed in the moving scope of vehicle glass inner surface rain brush brush usually, must adopt the non-contact detection technology, respond to rainfall and the moving effect of induction rain brush brush simultaneously and provide the advantage of real-time feedback signal for the rain brush controller thereby it has, it is installed in and has also avoided pollution and the damage of environment to it in the car.The internally-arranged type Raindrop sensor has become main flow in the Hyundai Motor industry.
The internally-arranged type Raindrop sensor of extensive use all is a photoelectric type in auto industry at present, the photoelectric type Raindrop sensor is divided into two kinds of forms again, first kind is that a camera is installed behind the vehicle glass inner surface, utilizes the image-forming principle that is similar to camera that the image of camera collection is carried out graphical analysis and handles variation with the perception rainfall.The senser element of this photoelectric type Raindrop sensor, data processing circuit and computer costs are too high, also are not applied in auto industry at present.The photoelectric type Raindrop sensor of second kind of form below only is discussed, it is widely adopted in auto industry, it is at the vehicle glass inner surface a pair of beam emissions and receiving system to be installed, utilize reflection of light and refraction principle, thereby the refractive index that is attached with the raindrop time when the vehicle glass outer surface will change and cause receiving terminal to accept intensity variations, thereby Raindrop sensor is transformed into intensity variations the variation of the variation perception rainfall of the signal of telecommunication.There is following defective in photoelectric type internally-arranged type Raindrop sensor:
1, measured area is little.When spotting on the unit are raindrop to distribute be uneven, therefore if measured area cross the young pathbreaker and cause automatic Wiper system slow in reacting.The transmitter components of photoelectric type Raindrop sensor generally is a point-source of light, although can use lens or prism, the scattering that light beam is carried out to a certain degree reflects area to enlarge, but this will cause adverse effect to the receiving sensitivity of receiving element, therefore, practical photoelectric type Raindrop sensor measured area certainly be provided with and manyly bring in the expansion measured area to transmitting and receiving, but this will raise the cost greatly usually all in 1 to 2 square centimeter.
2, can't measure thickness attached to the glass surface rainwater.The vehicle glass outer surface will be covered uniformly by rainwater when raining heavily, this moment, the size of rainfall can only be passed through from the thickness measurement attached to the glass surface rainwater, thereby will cause the slow influence brush of automatic Wiper system responsiveness rain effect if can't measure the rainwater varied in thickness.The operation principle of photoelectric type Raindrop sensor is to utilize the ray refraction rate to change, and refractive index is only relevant with the substance characteristics of the plane of incidence, and irrelevant with the thickness of material, therefore, the photoelectric type Raindrop sensor can't reflect the varied in thickness of rainwater.
3, be easy to be subjected to the interference of pollutant.When the vehicle glass outer surface is subjected to pollutant (as: dust, dirt, oil stain, winged insect corpse etc.) pollution, also will cause the bigger variation of ray refractive index, thereby the photoelectric type Raindrop sensor is because of distinguishing the misoperation that pollutant and rainwater cause automatic Wiper system.
4, require too high to mounting process.The photoelectric type Raindrop sensor requires to transmitting and receiving end accurate setting angle and distance are arranged, simultaneously the auxiliary lens and the position and the angle of prism system also there is very high requirement, in addition, consider the influence of thump, requiring to install must be very fastening, thereby in order to avoid because thump causes departing from of light to influence the precision and the sensitivity of transducer.
5, bad adaptability.The operation principle of photoelectric type Raindrop sensor is very poor to the adaptability of different vehicle glasses, the material of glass can influence refractive index and reflectivity, the thickness of glass can influence the setting angle and the position of transmitting terminal and receiving terminal, therefore need design corresponding photoelectric type Raindrop sensor at different vehicle glasses.
6, material, installation, time cost are higher.Photoelectric emission and receiving system, lens and material costs such as prism system, securing member that the photoelectric type Raindrop sensor needs are higher, since the high request of mounting process cause install and time cost higher, this is that at present automatic Wiper system only appears at the basic reason on the medium-to-high grade car.
Except that above-mentioned photoelectric type Raindrop sensor, a small amount of employing condenser type raindrop transducer is arranged also in the prior art.For example,
1, China Patent No. is 02147854.6, and it is a kind of by some chip capacitor pole plates parallel plate capacitor formula externally positioned type rain sensor that forms in parallel that this patent provides, and the shell of this transducer is provided with water inlet and delivery port, and rainwater is done direct contact type measurement.This transducer has the exemplary shortcomings of externally positioned type rain sensor, promptly can not feed back the moving effect of rain brush brush, can't constitute closed-loop control system; Vulnerable to pollution and damage; Complex structure.This transducer adopts traditional parallel plate type capacitive measuring principle.
2, patent document US4805070A, by name " capacity coupled humidity sensor ", its senser is a resistor network, utilize the principle of parallel plate type electric capacity that changes in resistance is capacitively coupled to signal generator and receiver by two constant parallel plate types, its essence is traditional resistance-type humidity sensor, this technical scheme has only provided the contactless method that is connected of a kind of signal processing circuit and senser (resistor network), carries out the difficult problem that lead connects to avoid passing through glass.The technical scheme that above-mentioned patent provides, its senser is installed on the outer surface of vehicle glass, direct contact type during to the measurement of rainwater, senser is installed on the outer surface of vehicle glass will propose very harsh requirement to senser material and mounting process, for example: corrosion-resistant, wear-resisting wiping, resistant can not influence regular event of rain brush or the like.Simultaneously, senser is installed in and carries out the electrical connection problem that contact type measurement just must solve senser on the outer surface of vehicle glass, so the technical scheme that above-mentioned patent provides provides the very complicated contactless method of attachment that forms the parallel plate type coupling capacitance in the crack of layer glass with the vehicle glass outer surface, this method technology is too complicated, and installation cost is inevitable too high.
3, the technical scheme that provides of the technical scheme measuring principle that provides of patent document US5668478A and US4805070A is similar, also be the variation of the measuring resistance of contact, carries out the signal coupling with parallel plate type electric capacity, has the same defective of US4805070A.
4, patent document EP0333564A1, the electronics rainwater sniffer that this patent document provides has utilized the principle of measuring electric capacity, but the transducer that this patent provides is typical externally positioned type contact type measurement rain sensor, and this transducer requires to have a water resistance good insulation performance cover layer.This transducer has the typical defect of externally positioned type rain sensor, promptly can not feed back the moving effect of rain brush brush, can't constitute closed-loop control system; Vulnerable to pollution and damage; Complex structure.
5, patent document DE3937605A1, the measuring principle of this transducer is traditional parallel plate type capacitive measuring principle, it is when water layer occurring on windshield in disclosed technical scheme, capacitor board can constitute a capacitor separately with water layer, obviously can only constitute two plane-parallel capacitors independently separately like this.The major defect of this transducer is, he requires capacitor plate must be installed between double glazing and two function films, and this can limit the scope of application of this transducer undoubtedly, and the windshield that uses of auto industry has the double-deck individual layer that also has at present.In addition, also there is complex structure in this transducer, defectives such as installation and lead-in wire difficulty.
In order to solve the problems of above-mentioned existence, the applicant was on September 19th, 2003, applied for the ZL03160008.5 patent of invention, name is called a kind of flat capacitance type intelligence Wiper system transducer automatically, comprise: one is installed in the lip-deep planar capacitor of shield glass, with the senser as transducer, two pole plates of wherein said planar capacitor are placed at grade; A sensor detection circuit detects the affected by environment and electric capacitance change brought of described planar capacitor, and produces the control signal of control rain brush work according to the electric capacitance change that is detected.This scheme can be installed transducer the inner surface of shield glass, and is positioned at the moving scope of rain brush brush, thereby has thoroughly solved the problem that above-mentioned many prior aries exist.But this scheme does not solve temperature floats the problem that impacts for the accuracy of detection of transducer with electromagnetic interference.At first, two electrodes of planar capacitor directly are attached on the windshield glass of automobile inner surface, because changing, the speed of a motor vehicle causes the windshield glass variations in temperature greatly, and temperature directly influences the change in dielectric constant of glass, cause the temperature drift of measuring-signal, consequence is to make to measure the sensitivity instability, even causes the windscreen wiper misoperation; Secondly, be attached to the reception antenna of the planar capacitor formation wireless electromagnetic signal on the windshield glass of automobile inner surface, can't shield again, when running into wireless electromagnetic interference by force, possible windscreen wiper causes misoperation.
Summary of the invention:
One of the technical problem to be solved in the present invention is the deficiency that overcomes above-mentioned prior art, provide a kind of temperature of can eliminating to float plane capacitance sensor with electromagnetic interference, this apparatus structure is simple, and can overcome simultaneously that the measured area that existing photoelectric type and flat capacitance type checkout gear exist is little, energy measurement rainwater thickness, vulnerable to pollution thing disturb, installation requirement is too high, deficiency such as bad adaptability and cost are higher.
Another technical problem that the present invention will solve provides a kind of temperature of can eliminating and floats method with the detection windshield environmental change of electromagnetic interference, and this method is simple and practical, is beneficial to popularization.
A kind of plane capacitance sensor that provides according to technical problem one to be solved by this invention, comprise that one is installed in the planar capacitor and a sensor detection circuit that is connected with described planar capacitor on the shield glass, described planar capacitor is as the senser of transducer, two pole plates of wherein said planar capacitor are placed at grade, described sensor detection circuit detects the affected by environment and electric capacitance change brought of described planar capacitor, and produce the control signal of control rain brush equipment work according to the electric capacitance change that detected, it is characterized in that: described sensor detection circuit also is connected with the plane capacitance compensator of an elimination interference signal, two pole plate is placed at grade, described plane capacitance compensator is only as the senser that detects interference signal, described sensor detection circuit detects the electric capacitance change that described plane capacitance compensator is influenced by interference signal to bring, and compensates described planar capacitor (1) electric capacitance change of bringing affected by environment according to the electric capacitance change that is detected.
Also have following attached technical characterictic according to a kind of plane capacitance sensor provided by the invention:
A kind of embodiment provided by the invention is that described plane capacitance compensator and described planar capacitor front and back on windshield be arranged in parallel.
Described plane capacitance compensator is identical with shape, size, the static capacitance value of described planar capacitor.
Described planar capacitor is positioned at the interlayer of windshield, and described plane capacitance compensator is positioned at the inner surface of the windshield relative with described planar capacitor position.
Described planar capacitor is close to the inner surface of windshield, and described plane capacitance compensator is positioned at the back of described planar capacitor, and by forming a determining deviation between an insulation material layer and the described planar capacitor.
Another embodiment provided by the invention is that described plane capacitance compensator and described planar capacitor are installed at grade.
Described plane capacitance compensator and described planar capacitor are installed on the inner surface of windshield.
Described plane capacitance compensator is positioned at described planar capacitor.
Described plane capacitance compensator is near the side of described planar capacitor.
Shared one of them pole plate of described capacitive compensator and described planar capacitor.
The gross area of the two-plate of described plane capacitance compensator is less than the gross area of the two-plate of described planar capacitor, and the spacing between the two-plate of described plane capacitance compensator is less than the thickness of its position glass, and the spacing between the two-plate of described planar capacitor is equal to or greater than the thickness of its position glass.
The electric conducting material that the two-plate of described planar capacitor and described plane capacitance compensator adopts is copper, aluminium, silver, conductive rubber, conductive plastics, transparent conductive film or conducting resinl; It is bonding, press solidly or be sprayed on the inner surface of windshield.
The two-plate of described planar capacitor and described plane capacitance compensator is shaped as rectangle, annular, fan-shaped, triangle or polygon.
The gross area of the two-plate of described planar capacitor is the 10-20 square centimeter, and the gross area of the two-plate of described plane capacitance compensator is the 5-11 square centimeter.
A kind of embodiment of sensor detection circuit provided by the invention is, described sensor detection circuit comprises signal generator, program control analog signal is amplified and filter circuit, difference channel, analog to digital conversion circuit, microprocessor, described signal generator produces the test signal of an access planar capacitor and plane capacitive compensator, when described test signal is flowed through described planar capacitor and described plane capacitance compensator, be affected by the external environment and change, test signal after two variations is imported described program control analog signal respectively and is amplified and filter circuit, amplify with filtering after, produce two d. c. voltage signals, two described d. c. voltage signals are after described difference channel carries out difference processing, produce a differential signal, described differential signal converts digital signal to via analog-digital conversion circuit as described, described microprocessor receives described digital signal, described digital signal is handled, formed the transducer digital output signal of control appliance work.
Another embodiment of sensor detection circuit provided by the invention is, described sensor detection circuit comprises signal generator, program control analog signal is amplified and filter circuit, analog to digital conversion circuit, microprocessor, described signal generator produces the test signal of an access planar capacitor and plane capacitive compensator, when described test signal is flowed through described planar capacitor and described plane capacitance compensator, be affected by the external environment and change, test signal after two variations is imported described program control analog signal respectively and is amplified and filter circuit, amplify with filtering after, produce two d. c. voltage signals, two described d. c. voltage signals convert two digital signals to via analog-digital conversion circuit as described respectively, described microprocessor receives two described digital signals, two described digital signals are carried out calculus of differences, and form the transducer digital output signal of control appliance work according to the result of calculus of differences.
Described planar capacitor is installed in the zone of windshield wiper work, and in equipment work, this device continues glass surface is detected and form feedback signal, and further control appliance work constitutes closed-loop control system.
Described test signal is sine wave signal, square-wave signal or triangular signal.
The frequency of described test signal is 100kHZ-1000kHZ, and the static capacitance value of described planar capacitor and described plane capacitance compensator is between 50-400pf.
According to a kind of method that detects the windshield environmental change that technical problem two to be solved by this invention provides, its process is as follows:
A, initialization transducer;
Signal generator in b, the transducer produces test signal, and described test signal is transferred to respectively in planar capacitor and the plane capacitive compensator;
C, detect the test signal variation that the variation that brought and test signal influence by interference signal to bring that when described planar capacitor, is affected by the external environment respectively when described plane capacitance compensator;
D, change test signals with detected two and carry out calculus of differences;
E, processing unit generate control signal according to differential signal;
F, transmission of control signals are to equipment;
G, transducer detect glass surface once more, generate feedback signal, are transferred to processing unit, constitute closed-loop control system.
Have following advantage according to plane capacitance sensor provided by the invention with respect to prior art: the present invention adopts biplane electric capacity, one of them plane capacitance is as measuring electric capacity, another is electric capacity by way of compensation, make its rainwater insensitive by installation site and the shape that changes building-out capacitor, and temperature is floated and the electromagnetic interference sensitivity glass outer surface.When meeting that temperature is floated or during electromagnetic interference, the measured value of measuring electric capacity and building-out capacitor takes place to change simultaneously and the amplitude of variation approximately equal simultaneously, measure capacitance when rainwater changes and change thereupon when meeting, and the building-out capacitor value remains unchanged substantially.Utilize above characteristic to carry out the difference compensation, reduce temperature effectively and float and the electromagnetic interference adverse effect that sensitivity brings to sensor measurement, avoid the windscreen wiper misoperation measurement value sensor.
Simultaneously, the present invention is as built-in planar capacitance sensor, and it also has the following advantages:
1, measured area is big.The plane capacitance pole plate can be made arbitrary shape, measured area can enlarge arbitrarily under the condition that does not influence pilot's line of vision, can fundamentally avoid the too small detection system of bringing of photoelectric type Raindrop sensor measured area drawback slow in reacting like this.
2, can measure thickness attached to the glass surface rainwater.Because the dielectric space of plane capacitance is near the space that is similar to the semiellipse spherical pole plate upper glass and glass surface and the outer surface, in this spatial dimension, thereby the variation of rainwater thickness will cause the variation of condenser dielectric spatial dielectric constant to cause the variation of capacitance.Thereby just having overcome the photoelectric type Raindrop sensor, this can't measure the defective that the rainwater varied in thickness causes the slow influence brush of automatic Wiper system responsiveness rain effect.
3, be not vulnerable to the interference of pollutant.Because the relative dielectric constant of water is more much bigger than general pollutant, therefore plane capacitance sensor is easy to pollutant and water are made a distinction the variation that capacitance causes, thereby has solved the photoelectric type Raindrop sensor because the influence of contaminated thing causes the problem of automatic Wiper system misoperation.
4, mounting process is very simple.That plane capacitance sensor can adopt is bonding, crimping, spraying or various process at the glass surface plating form planar capacitor in interior surfaces of glass, need as the photoelectric type Raindrop sensor not to need accurately location.
5, adaptability is strong.Because it is big tens times that the permittivity ratio glass of water is wanted, so the variation of glass material and thickness can ignore to the influence that sensor accuracy and sensitivity cause, and same plane capacitance sensor almost can adapt to various vehicle glasses.Be not required to be the special transducer of various vehicle glass designs.
6, material, installation, time cost significantly reduce.Plane capacitance sensor can be selected various electric conducting materials for use, as: Copper Foil, aluminium foil, conductive rubber, conductive plastic film, glass surface spraying plating etc., and the amount of having is seldom, and general needs about ten square centimeters, so material cost is extremely low.Because install simply, installation and installation work-hour cost are also much lower than photoelectric type Raindrop sensor.
7, of the present invention can being installed in easily in the moving scope of windshield wiper brush, therefore, effect that can team's rain brush work detects, and constitutes closed-loop control system.
Have following advantage according to a kind of method that detects the windshield environmental change provided by the invention: this method detects measuring-signal and compensating signal simultaneously, and two signals are carried out difference processing, and according to differential signal, the work of control relevant device, having eliminated temperature floats and the influence of electromagnetic interference to transducer, this method is beneficial to realization, is fit to promotion and application.
Description of drawings:
Fig. 1 is point charge electric field line distribution figure;
Fig. 2 is a parallel plate type capacitive field line distribution map;
Fig. 3 is the planar capacitor electric field line distribution figure of 2 rectangle pole plates of the present invention;
Fig. 4 is the measurement space schematic diagram that the planar capacitor of 2 rectangle pole plates of the present invention forms;
Fig. 5 is equivalent capacity measurement model figure of the present invention;
Fig. 6 is the cross-sectional schematic of an embodiment of the present invention, is arranged at the interlayer of windshield and the schematic diagram of inner surface before and after planar capacitor shown in the figure and the plane capacitive compensator, and the measurement space that both form is shown among the figure simultaneously.
Fig. 7 is the cross-sectional schematic of the another kind of embodiment of the present invention, is arranged at the schematic diagram of the inner surface of windshield before and after planar capacitor shown in the figure and the plane capacitive compensator, and the measurement space that both form is shown among the figure simultaneously.
Fig. 8 is that the pole plate of midplane capacitor of the present invention and plane capacitive compensator is the schematic diagram of rectangle.
Fig. 9 is the schematic diagram of the pole plate of midplane capacitor of the present invention and plane capacitive compensator for annular.
Figure 10 is midplane capacitor of the present invention and plane capacitive compensator setting schematic diagram at grade.
Figure 11 is that the pole plate of midplane capacitor of the present invention and plane capacitive compensator is the schematic diagram of rectangle and shared one of them pole plate.
Figure 12 is the schematic diagram of the pole plate of midplane capacitor of the present invention and plane capacitive compensator for annular and shared one of them pole plate.
Figure 13 is the profile of mounting structure of the present invention.
Figure 14 is the block diagram of a kind of embodiment of plane capacitance testing circuit of the present invention.
Figure 15 is the block diagram of the another kind of embodiment of plane capacitance testing circuit of the present invention.
Provide embodiment below in conjunction with accompanying drawing, invention be elaborated:
Embodiment:
Before describing the present invention in detail, sketch prior art and operation principle of the present invention earlier:
Traditional capacitance type sensor is based on parallel plate type electric capacity, and its principle is: if do not consider the edge effect of inhomogeneous field, and the electric capacity that two parallel-plates are formed, its capacitance is
C＝ε·S/d
In the formula, ε is the dielectric constant of medium between pole plate, and ε=ε 0 ε r, ε 0 are the dielectric constant in the vacuum, ε 0=8.85410
-12F/m, ε r are the dielectric constants of medium relative vacuum, the relative dielectric constant ε r ≈ 1 of air, other medium ε r＞1; S is the area of pole plate; D is the spacing of pole plate.
Because the variation of measured medium causes that capacitance type sensor has related parameter ε, S, the variation of d changes capacitance C thereupon.In view of the above, traditional capacitance type sensor can be divided into three types with the variation of different parameters: become space type (parameter d variation); Variable area formula (parameter S variation); Become dielectric constant formula (parameter ε variation).
The planar capacitor that the present invention proposes has been broken the thinking set of traditional capacitance type sensor based on the parallel plate type capacitance principle from principle, and it press the certain interval placement at grade with two pole plates of capacitor, rather than parallel placement.It does not belong to any of above-mentioned three kinds of conventional condenser sensor types, and it is a kind of comprehensive capacitance type sensor, and it has the characteristic that becomes space type, variable area formula and become dielectric constant formula capacitance sensor simultaneously.
Capacitive measuring principle of the present invention is as follows:
According to the vector superposed principle of the field intensity of electric field theory, we know that the characteristic of capacitor can be described with electric field line distribution, referring to Fig. 1 and Fig. 2, provide the electric field line distribution of point charge and parallel plate capacitor respectively, among the figure, and the 10th, electric field line, 28 and 29 is point charges.Be convenient following discussion, Fig. 3 provides the electric field line distribution of semicircle planar capacitor.By among Fig. 2 as can be seen, the electric field line 10 of parallel plate capacitor mainly is distributed in the coffin between two parallel-plates, therefore when calculating the capacitance of parallel plate capacitor, the influence that can ignore the parallel-plate fringe field draws the capacitance computing formula of parallel plate capacitor: C=ε S/d.In like manner, as seen from Figure 3, the electric field line of planar capacitor mainly is distributed in the approximate ellipsoidal spheroid space of two plane electrode panel areas, because the Theoretical Calculation of plane capacitance is too complicated, does not go through herein.
Referring to Fig. 3 and Fig. 4, there is shown the electric field line spatial distribution of the planar capacitor under the applied environment that the present invention relates to, two plane electrode plates 11,12 are close to below the glass 9, by the distribution shape of the electric field line among Fig. 3 and Fig. 4 10 as can be seen, owing to be subjected to the different medium influence, two plane electrode plates 11 can be divided into three different spaces with battery lead plate 12 approximate ellipsoidal spheroid space on every side: vehicle glass 9 inner surfaces and the plane electrode plate 11 and the approximate half elliptic spheroid space N1 of battery lead plate below 12 that are close on the inner surface; The flat elliptic space N2 that more than 12 and vehicle glass 9 inside of plane electrode plate 11 and battery lead plate comprise; Near the half elliptic space Nx that forms vehicle glass 9 outer surfaces.Because the medium of approximate half elliptic spheroid space N1 and flat elliptic space N2 is respectively uniform air and glass, its dielectric constant and volume can be thought constant.And half elliptic space Nx is air usually, and when other foreign matters enter, bigger variation will take place for its dielectric constant and volume, and half elliptic space Nx is our measurement space just.
Based on above discussion, referring to Fig. 5, the equivalent capacity model that the present invention proposes.Wherein, equivalent capacity C3 in parallel is the constant electric capacity of being determined by half approximate ellipsoidal spheroid space N1 and flat elliptic space N2, series capacitance C1 and C2 are by passing through the vehicle glass outer surface more than the plane electrode but are enclosed in the constant electric capacity of vehicle glass outer surface with interior space decision that Cx is the variable capacitance that half elliptic space Nx forms.The capacitance of Cx depends on the dielectric constant of the foreign matter that enters half elliptic space Nx, the area that foreign matter covers, the thickness that foreign matter forms at half elliptic space Nx simultaneously, and this thickness can be equal to the spacing of plane-parallel capacitor in theory.
By above discussion to the principle of the invention, we can obtain following 2 conclusions:
1, the capacitance type sensor of the planar capacitor that proposes of the present invention any type different from the past, comprise: variable area, change spacing type and change dielectric constant type, it is comprehensive capacitance type sensor, the variation of its area of perception simultaneously, spacing and three parameters of dielectric constant.
2, the planar capacitor of the present invention's proposition not only can be distinguished the foreign matter of vehicle glass near surface, and perception simultaneously covers transducer area and the thickness that the glass surface foreign matter covers of getting on the car, and this existing just electro-optical pickoff can't be accomplished.
After having set forth inventive principle of the present invention, provide the plane capacitance sensor that utilizes above-mentioned principle to produce below.
Referring to Fig. 6 and Fig. 8, as a preferred embodiment of the present invention, adopt one side to have the copper foil tape of adhesive sticker, being processed into width is a=2cm, length is 2 rectangular electrode plates 11,12 of b=4cm, the gross area of described battery lead plate 11,12 is 16 square centimeters, and the gap between the two-plate is 0.6cm.On the inner surface of the windshield glass of automobile 9 that described battery lead plate 11,12 sticks on, be positioned at the position that automobile rearview mirror 19 back do not influence pilot's line of vision and are in the moving scope of rain brush brush.Form two electrodes of planar capacitor 1 thus.Be installed in the purpose that can realize non-contact measurement on the inner surface of windshield 9.Simultaneously, the installation site of described planar capacitor 1 belongs to rain brush blows in the working range of rain, and not only whether rainy existence detects to glass surface, and the effect of rain brush work is detected.The spacing of described pole plate 11,12 is greater than the thickness of glass of its position.The magnetic field of its formation just has outside most outer surface that is positioned at glass like this, forms to measure the semiellipse magnetic field space Nx that rainwater is used.
Referring to Fig. 7 and Fig. 8, in the foregoing description that provides according to the present invention, in order to eliminate the influence of temperature and electromagnetism to planar capacitor 1, the present invention is arranged with plane capacitance compensator 2 in parallel in the back of described planar capacitor 1, two pole plates of described plane capacitance compensator 2 and two pole plates of described planar capacitor 1 are identical, and its spacing also is the same.Finally make described plane capacitance compensator 2 identical with shape, size, the static capacitance value of described planar capacitor 1.In order to make described plane capacitance compensator 2 not to the rainwater sensitivity, an insulation material layer 4 is set between planar capacitor 1 and plane capacitive compensator 2, form a determining deviation.Thereby the magnetic field space that plane capacitance compensator 2 is formed is no more than the outer surface of shield glass, does not promptly have and measures the magnetic field space Nx that rainwater is used.
Referring to Fig. 6, the scheme that described planar capacitor 1 that the present invention provides and described plane capacitance compensator 2 front and back be arranged in parallel, when mounted, also described planar capacitor 1 can be installed in the interlayer of shield glass 9, described plane capacitance compensator 2 is positioned at the inner surface of the shield glass 9 relative with described planar capacitor 1 position.But the magnetic field that will guarantee described plane capacitance compensator 2 equally all is positioned at below the outer surface of glass, does not promptly have to measure the magnetic field space Nx that rainwater is used.
Referring to Figure 10 and Figure 11, in the another kind of preferred embodiment that the present invention provides, described plane capacitance compensator 2 is installed on the same plane of shield glass 9 with described planar capacitor 1.And all be positioned on the inner surface of shield glass 9.A pole plate 21 of described plane capacitance compensator 2 is shared with one of them pole plate 12 of described planar capacitor 1, another pole plate 22 of described plane capacitance compensator 2 is positioned at a side of described shared pole plate, its width is 0.2cm, and length is 4cm, with the gap of shared pole plate 12 be 0.1cm.The gross area of the two-plate of described plane capacitance compensator 2 is 8.8 square centimeters.The gross area of the two-plate of described plane capacitance compensator 2 is less than the gross area (16 square centimeters) of the two-plate of described planar capacitor 1, and the spacing between the two-plate of described plane capacitance compensator 2 is far smaller than the thickness of its position glass 9.The magnetic field that guarantees described plane capacitance compensator 2 so all is positioned at below the outer surface of glass 9, does not promptly have to measure the magnetic field space Nx that rainwater is used.
Referring to Figure 12, what the present invention provided is arranged on described planar capacitor 1 and described plane capacitance compensator 2 in the conplane scheme, also described plane capacitance compensator 2 can be arranged on described planar capacitor 1 inside.In another scheme that provides as the present invention, in two pole plates of described planar capacitor 1, one is ring plate 11, and a circular pole plate 12 is set in ring plate 11.One less circular pole plate 22 is set in the circular pole plate 12 of described planar capacitor 1 again, makes big circular pole plate 12 become shared pole plate, thereby constitute described plane capacitance compensator 2.The spacing of small circular pole plate 22 and big circular pole plate 12 is far smaller than the thickness of its place glass, thus, guarantees that the magnetic field of described plane capacitance compensator 2 all is positioned at below the outer surface of glass, does not promptly have to measure the magnetic field space Nx that rainwater is used.
In the above-mentioned various embodiments that the present invention provides, no matter be which kind of embodiment, final purpose all is that the magnetic field that guarantees described plane capacitance compensator 2 all is positioned at below the outer surface of glass 9, does not promptly have and measures the magnetic field space Nx that rainwater is used.Only in this way just can make 2 pairs of rainwater of described plane capacitance compensator insensitive,, become the senser that only detects interference signal only to temperature and electromagnetic interference signal sensitivity.
Referring to Figure 13, in the embodiment that the present invention provides, the pole plate of described planar capacitor 1 and described plane capacitance compensator 2 is connected to sensor detection circuit 3 with shielded conductor 14 respectively.For preventing that the people from being accidental damage; conical plastic protective cover 24 on the rear mask of described planar capacitor 1 and described plane capacitance compensator 2; conical plastic protective cover 24 cements on the inner surface of windshield glass of automobile 9; be guard shield lead 14; shielded conductor 14 is drawn out in the interlayer of roof hood 17 and roof interior trim 16 at conical plastic protective cover 24 upper sides by plastic bushing 13; two shielded conductors 14 are connected electrically on the circuit board 15 that is installed in roof hood 17 and roof interior trim 16 interlayers; circuit board 15 carries out electromagnetic shielding and protection by the plastic casing 23 that has screen, and the digital output signal of transducer is sent to the control unit of automatic Wiper system by shielding LIN bus cable 18.
Referring to Figure 14, in the foregoing description that the present invention provides, described sensor detection circuit 3 comprises signal generator 31, program control analog signal is amplified and filter circuit 32, difference channel 33, analog to digital conversion circuit 34, microprocessor 35, described signal generator 31 produces the sinusoidal wave test signal 36 of an access planar capacitor 1 and plane capacitive compensator 2, when described test signal 36 is flowed through described planar capacitor 1 and described plane capacitance compensator 2, be affected by the external environment and change, test signal 36 after two variations is imported described program control analog signal respectively and is amplified and filter circuit 32, amplify with filtering after, produce two d. c. voltage signals 37, two described d. c. voltage signals 37 are after described difference channel 33 carries out difference processing, produce a differential signal, described differential signal converts digital signal to via analog-digital conversion circuit as described 34, described microprocessor 35 receives described digital signal, this digital signal in microprocessor 35 through digital filtering, digital linearization handle and the adjustment of digital adaptation algorithm after form transducer numeral output control signal be sent to shielding LIN (LocalInterconnect Network scene is connected network) bus interface circuit 38, then, be sent to the control unit of automatic Wiper system by shielding LIN bus cable 18.After the rain brush work, this device continues glass surface is detected and form feedback signal, further controls the work of rain brush, constitutes closed-loop control system, thereby makes this device control the work of rain brush according to the size of raindrop.The test signal that the present invention provides also can be square-wave signal or triangular signal.The frequency of described test signal 36 can be between 100kHZ-1000kHZ, and the frequency that adopts in the present embodiment is 230KHZ, and the static capacitance value of described planar capacitor 1 and described plane capacitance compensator 2 is between 50-400pf.The capacitance that adopts in the present embodiment is 220pf.
Referring to Figure 15, among another embodiment that the present invention provides, described sensor detection circuit 3 comprises signal generator 31, program control analog signal is amplified and filter circuit 32, analog to digital conversion circuit 34, microprocessor 35, described signal generator 31 produces the test signal 36 of an access planar capacitor 1 and plane capacitive compensator 2, when described test signal 36 is flowed through described planar capacitor 1 and described plane capacitance compensator 2, be affected by the external environment and change, test signal 36 after two variations is imported described program control analog signal respectively and is amplified and filter circuit 32, amplify with filtering after, produce two d. c. voltage signals 37, two described d. c. voltage signals 37 convert two digital signals to via analog-digital conversion circuit as described 34 respectively, described microprocessor 35 receives two described digital signals, two described digital signals are carried out calculus of differences, and with the digital signal behind the calculus of differences in microprocessor 35 through digital filtering, digital linearization handle and the adjustment of digital adaptation algorithm after form transducer numeral output control signal be sent to shielding LIN (Local Interconnect Network scene is connected network) bus interface circuit 38, then, be sent to the control unit of automatic Wiper system by shielding LIN bus cable 18.After the rain brush work, this device continues glass surface is detected and form feedback signal, further controls the work of rain brush, constitutes closed-loop control system, thereby makes this device control the work of rain brush according to the size of raindrop.
In the foregoing description that the present invention provides, the electric conducting material that pole plate adopted of described planar capacitor 1 and plane capacitive compensator 2 is copper, aluminium, silver, conductive rubber, conductive plastics, conducting resinl or transparent conductive film, by multiple mounting means as: paste, press solidly, spray, the position that does not influence pilot's line of vision on vehicle glass 9 inner surfaces forms the required pole plate of described planar capacitor 1 and plane compensation condenser 2, pole plate can be multiple shape, for example rectangle, annular, fan-shaped, triangle or polygon.The ring plate that provides as Fig. 9.The pole plate that should guarantee planar capacitor 1 during installation closely contacts with glass 9 inner surfaces, avoids influencing because of the air gap performance of transducer, and the glass surface plating is a best choice.Experiment shows, the gross area of the pole plate of planar capacitor 1 less than 100 square centimeters can, but from saving cost, and the two-plate gross area of the described planar capacitor 1 of result of use is that the 10-20 square centimeter is best.And the two-plate gross area of plane capacitance compensator 2 is that the 5-11 square centimeter is best.
Provide the detection method of utilizing said apparatus the windshield surface to be carried out environmental change below:
According to detection method provided by the invention, its process is as follows:
A, initialization transducer;
C, detect test signal 36 variation that the variation that brought and test signal 36 influence by interference signal to bring that when described planar capacitor 1, is affected by the external environment respectively when described plane capacitance compensator 2;
D, change test signals 36 with detected two and carry out calculus of differences;
E, processing unit generate control signal according to differential signal;
F, transmission of control signals are to equipment;
G, transducer detect glass surface once more, generate feedback signal, are transferred to processing unit, constitute closed-loop control system.
The present invention is according to the area of the material of vehicle glass and thickness, planar capacitor 1 sensing element and mounting means, ambient temperature, damp condition for the initialization of transducer, detects and set the static initial value of planar capacitor 1 sensing element.Because different materials, its dielectric constant is different, so checkout gear can be provided with different initial values according to different materials, thereby judges it is which kind of material is attached to glass surface.For example, when water during attached to the glass surface at planar capacitor 1 place, the capacitance of planar capacitor 1 changes, and the variable quantity of capacitor is set with this moment, as judging the standard of water attached to glass surface.
Method of the present invention is realization like this: be provided with planar capacitor 1 and plane capacitive compensator 2 on the inner surface of windshield 9, two pole plates 11,12 of described planar capacitor 1 are placed at grade, it changes with the rainwater that detects windshield 9 surfaces as senser, and described planar capacitor 1 is influenced by the rainwater size and signal that the capacitance Cx that brings changes is transferred to sensor detection circuit 3.Two pole plates 21,22 of described plane capacitance compensator 2 also are to place at grade, because its installation site or shape are different with described planar capacitor 1, the rainwater size can not influence its capacitance.Therefore, it can only detected temperatures and electromagnetic interference variation that its capacitance is brought, and variable signal is transferred in the described sensor detection circuit 3.Described sensor detection circuit 3 carries out calculus of differences according to the two variation test signals that detected, and produces the control signal of control appliance work according to the result of calculus of differences.Because, described planar capacitor 1 and described plane capacitance compensator 2 be subjected to temperature and electromagnetic interference effect and the test signal brought to change be to change synchronously simultaneously and the amplitude of variation approximately equal.And change for rainwater, the test signal of only described planar capacitor 1 changes.According to above-mentioned characteristic, carry out calculus of differences after, can effectively eliminate the influence that temperature and electromagnetic interference cause.Improve the accuracy of detection of transducer, realized final goal of the invention of the present invention.
Claims (18)
1, a kind of plane capacitance sensor, comprise that one is installed in the planar capacitor (1) and a sensor detection circuit (3) that is connected with described planar capacitor (1) on the windshield (9), described planar capacitor (1) is as the senser of transducer, two pole plates of wherein said planar capacitor (1) are placed at grade, described sensor detection circuit (3) detects the affected by environment and electric capacitance change brought of described planar capacitor (1), and produce the control signal of control rain brush equipment work according to the electric capacitance change that detected, it is characterized in that: described sensor detection circuit (3) also is connected with the plane capacitance compensator (2) of an elimination interference signal, two pole plate is placed at grade, the gross area of the two-plate of described planar capacitor (1) is the 10-20 square centimeter, the gross area of the two-plate of described plane capacitance compensator (2) is the 5-11 square centimeter, described plane capacitance compensator (2) is only as the senser that detects interference signal, described sensor detection circuit (3) detects the electric capacitance change that described plane capacitance compensator (2) is influenced by interference signal to bring, and compensates described planar capacitor (1) electric capacitance change of bringing affected by environment according to the electric capacitance change that is detected.
2, plane capacitance sensor as claimed in claim 1 is characterized in that: described plane capacitance compensator (2) be arranged in parallel before and after windshield (9) is gone up with described planar capacitor (1).
3, plane capacitance sensor as claimed in claim 2 is characterized in that: described plane capacitance compensator (2) is identical with shape, the size of described planar capacitor (1).
4, plane capacitance sensor as claimed in claim 1 or 2, it is characterized in that: described planar capacitor (1) is positioned at the interlayer of windshield (9), and described plane capacitance compensator (2) is positioned at the inner surface of the windshield (9) relative with described planar capacitor (1) position.
5, plane capacitance sensor as claimed in claim 1 or 2, it is characterized in that: described planar capacitor (1) is close to the inner surface of windshield (9), described plane capacitance compensator (2) is positioned at the back of described planar capacitor (1), and by forming a determining deviation between an insulation material layer (4) and the described planar capacitor (1).
6, plane capacitance sensor as claimed in claim 1 is characterized in that: described plane capacitance compensator (2) is installed at grade with described planar capacitor (1).
7, plane capacitance sensor as claimed in claim 6 is characterized in that: described plane capacitance compensator (2) is installed on the inner surface of windshield (9) with described planar capacitor (1).
8, plane capacitance sensor as claimed in claim 6 is characterized in that: described plane capacitance compensator (2) is positioned at described planar capacitor (1) or near the side of described planar capacitor (1).
9, as claim 6 or 7 or 8 described plane capacitance sensors, it is characterized in that: described plane capacitance compensator (2) and shared one of them pole plate of described planar capacitor (1).
10, as claim 6 or 7 or 8 described plane capacitance sensors, it is characterized in that: the gross area of the two-plate of described plane capacitance compensator (2) is less than the gross area of the two-plate of described planar capacitor (1), and the spacing between the two-plate of described plane capacitance compensator (2) is less than the thickness of its position glass, and the spacing between the two-plate of described planar capacitor (1) is equal to or greater than the thickness of its position glass.
11, plane capacitance sensor as claimed in claim 1 is characterized in that: the electric conducting material that the two-plate of described planar capacitor (1) and described plane capacitance compensator (2) adopts is copper, aluminium, silver, conductive rubber, conductive plastics, transparent conductive film or conducting resinl; It is bonding, press solidly or be sprayed on the inner surface of windshield (9).
12, plane capacitance sensor as claimed in claim 1 is characterized in that: the two-plate of described planar capacitor (1) and described plane capacitance compensator (2) is shaped as rectangle, annular, fan-shaped, triangle or polygon.
13, plane capacitance sensor as claimed in claim 1, it is characterized in that: described sensor detection circuit (3) comprises signal generator (31), program control analog signal is amplified and filter circuit (32), difference channel (33), analog to digital conversion circuit (34), microprocessor (35), described signal generator (31) produces the test signal (36) of an access planar capacitor (1) and plane capacitive compensator (2), when described test signal (36) is flowed through described planar capacitor (1) and described plane capacitance compensator (2), be affected by the external environment and change, test signal (36) after two variations is imported described program control analog signal respectively and is amplified and filter circuit (32), amplify with filtering after, produce two d. c. voltage signals (37), two described d. c. voltage signals (37) are after described difference channel (33) carries out difference processing, produce a differential signal, described differential signal converts digital signal to via analog-digital conversion circuit as described, described microprocessor receives described digital signal, described digital signal is handled, formed the transducer digital output signal of control appliance work.
14, plane capacitance sensor as claimed in claim 1, it is characterized in that: described sensor detection circuit (3) comprises signal generator (31), program control analog signal is amplified and filter circuit (32), analog to digital conversion circuit (34), microprocessor (35), described signal generator (31) produces the test signal (36) of an access planar capacitor (1) and plane capacitive compensator (2), when described test signal (36) is flowed through described planar capacitor (1) and described plane capacitance compensator (2), be affected by the external environment and change, test signal (36) after two variations is imported described program control analog signal respectively and is amplified and filter circuit (32), amplify with filtering after, produce two d. c. voltage signals (37), two described d. c. voltage signals (37) convert two digital signals to via analog-digital conversion circuit as described (34) respectively, described microprocessor (35) receives two described digital signals, two described digital signals are carried out calculus of differences, and form the transducer digital output signal of control appliance work according to the result of calculus of differences.
15, as claim 13 or 14 described plane capacitance sensors, it is characterized in that: described planar capacitor (1) is installed in the zone of windshield wiper work, in rain brush work, this plane capacitance sensor continues glass surface is detected and form feedback signal, further control appliance work constitutes closed-loop control system.
16, as claim 13 or 14 described plane capacitance sensors, it is characterized in that: described test signal (36) is sine wave signal, square-wave signal or triangular signal, the frequency of described test signal (36) is 100kHZ-1000kHZ, and the static capacitance value of described planar capacitor (1) and described plane capacitance compensator (2) is between 50-400pf.
17, a kind of method that adopts the environmental change of the described sensor windshield of claim 1, its process is as follows:
A, initialization transducer;
Signal generator in b, the transducer (31) produces test signal (36), and described test signal (36) is transferred to respectively in planar capacitor (1) and the plane capacitive compensator (2);
C, detect test signal (36) variation that the variation that brought and test signal (36) influence by interference signal during through described plane capacitance compensator (2) to bring that is affected by the external environment when described planar capacitor (1) respectively;
D, change test signals (36) with detected two and carry out calculus of differences;
E, processing unit generate control signal according to differential signal;
F, transmission of control signals are to equipment;
G, transducer detect glass surface once more, generate feedback signal, are transferred to processing unit, constitute closed-loop control system.
18, the method for detection windshield as claimed in claim 17 environmental change, it is characterized in that: described transducer is installed in the zone of windshield wiper work.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200610083392 CN100571035C (en) | 2006-06-08 | 2006-06-08 | The method of plane capacitance sensor and the environmental change of detection windshield |
| PCT/CN2006/001973 WO2007140658A1 (en) | 2006-06-08 | 2006-08-04 | A plane capacitive sensor and a method for detecting environmental variation of vehicle windscreen |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200610083392 CN100571035C (en) | 2006-06-08 | 2006-06-08 | The method of plane capacitance sensor and the environmental change of detection windshield |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101087135A CN101087135A (en) | 2007-12-12 |
| CN100571035C true CN100571035C (en) | 2009-12-16 |
Family
ID=38801040
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200610083392 Active CN100571035C (en) | 2006-06-08 | 2006-06-08 | The method of plane capacitance sensor and the environmental change of detection windshield |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN100571035C (en) |
| WO (1) | WO2007140658A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2019057574A1 (en) | 2017-09-25 | 2019-03-28 | Saint-Gobain Glass France | Vehicle window, vehicle, and method for producing same |
Families Citing this family (25)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2356000B1 (en) * | 2008-11-20 | 2013-01-02 | ELMOS Semiconductor AG | Interference-compensated sensor |
| CN202417144U (en) * | 2011-12-21 | 2012-09-05 | 北京奥特易电子科技有限责任公司 | Clamp-proof sensor of electric vehicle window |
| DE102012102422A1 (en) * | 2012-03-21 | 2013-09-26 | Huf Hülsbeck & Fürst Gmbh & Co. Kg | Capacitive sensor arrangement for switching a door opening on a motor vehicle and associated method |
| DE102012006347A1 (en) * | 2012-03-28 | 2013-10-02 | Brose Fahrzeugteile Gmbh & Co. Kg, Hallstadt | Method for determining distance between object e.g. person and motor vehicle e.g. car, involves receiving light reflected by object using light receiver at predetermined angle of incidence |
| CN102830632B (en) * | 2012-08-16 | 2014-11-26 | 北京奥特易电子科技有限责任公司 | Monitor with cleaning device |
| CA2888649C (en) * | 2013-02-01 | 2017-08-22 | Serge V. Monros | Hydrogen on-demand fuel system for internal combustion engines |
| CN106285280B (en) * | 2015-06-03 | 2018-10-19 | 上海三菱电梯有限公司 | The capacitance type sensor anti-pinch detection device of sliding door |
| CN105352565A (en) * | 2015-11-02 | 2016-02-24 | 智恒（厦门）微电子有限公司 | Differential-capacitor material level sensor |
| CN106643823A (en) * | 2016-09-09 | 2017-05-10 | 天津易哲微电子技术有限公司 | Method for eliminating influence of temperature on capacitive encoder and capacitive encoder |
| CN106427903B (en) * | 2016-11-10 | 2023-06-06 | 湖南工业大学 | Wireless control's electronic windscreen wiper controlling means of locomotive |
| DE102017206480B3 (en) * | 2017-04-18 | 2018-06-14 | Audi Ag | Method for operating a capacitive rain sensor of a motor vehicle, measuring signal interference suppression device and motor vehicle with such a measurement signal interference suppression device |
| CN107733011A (en) * | 2017-10-12 | 2018-02-23 | 北京奥特易电子科技有限责任公司 | A kind of vehicle-mounted wireless charging device |
| MA53538A (en) | 2018-09-03 | 2021-12-08 | Saint Gobain | GLAZING UNIT |
| DE202018006225U1 (en) | 2018-09-04 | 2019-08-26 | Saint-Gobain Glass France | glazing unit |
| CN111225794A (en) | 2018-09-25 | 2020-06-02 | 法国圣戈班玻璃厂 | Composite glass plate and method for manufacturing same |
| CN111307885A (en) * | 2018-12-11 | 2020-06-19 | 上海微现检测设备有限公司 | Water-injected meat rapid detection method, detection system and detection device |
| CN113316076B (en) * | 2019-02-01 | 2023-03-24 | 深圳市汇顶科技股份有限公司 | Wearing detection device and method and earphone |
| EP4021719A1 (en) | 2019-08-26 | 2022-07-06 | Saint-Gobain Glass France | Laminated glass pane comprising an electronic functional module |
| DE102019132134A1 (en) * | 2019-11-27 | 2021-05-27 | Huf Hülsbeck & Fürst Gmbh & Co. Kg | Device for a vehicle for detecting an activation action in a detection area |
| CN112315031A (en) * | 2020-11-20 | 2021-02-05 | 河南中烟工业有限责任公司 | Cigarette detection method based on interelectrode capacitance dielectric constant change |
| CN116710812A (en) * | 2021-01-15 | 2023-09-05 | 深圳市大疆创新科技有限公司 | Environment information acquisition device, unmanned aerial vehicle base station, method and storage medium |
| CN112923955B (en) * | 2021-03-04 | 2022-06-07 | 西安交通大学 | Flexible capacitive sensor based on paper aluminum plastic packaging material |
| CN113085785A (en) * | 2021-03-18 | 2021-07-09 | 江苏开沃汽车有限公司 | Capacitive sensing wiper system for automobile and working method thereof |
| CN114199421A (en) * | 2021-12-13 | 2022-03-18 | 上汽大众汽车有限公司 | Differential capacitance type pressure sensor and method for accurately measuring pipeline fluid pressure by using same |
| CN115792441B (en) * | 2022-11-23 | 2024-02-13 | 苏州科标检测有限公司 | Radiation anti-interference test method and test system |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5682788A (en) * | 1995-07-12 | 1997-11-04 | Netzer; Yishay | Differential windshield capacitive moisture sensor |
| JP3453962B2 (en) * | 1995-10-31 | 2003-10-06 | 松下電工株式会社 | Capacitive rain sensor |
| JP2000075052A (en) * | 1998-08-28 | 2000-03-14 | Asahi Glass Co Ltd | Window glass with sensor for vehicle |
| US6373263B1 (en) * | 2000-04-20 | 2002-04-16 | Millennium Sensors Ltd. | Differential windshield capacitive rain sensor |
| CN1217204C (en) * | 2003-09-19 | 2005-08-31 | 孙滕谌 | Plane capacity type automatic wiper system intelligent sensor for automobile glass |
-
2006
- 2006-06-08 CN CN 200610083392 patent/CN100571035C/en active Active
- 2006-08-04 WO PCT/CN2006/001973 patent/WO2007140658A1/en active Application Filing
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2019057574A1 (en) | 2017-09-25 | 2019-03-28 | Saint-Gobain Glass France | Vehicle window, vehicle, and method for producing same |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101087135A (en) | 2007-12-12 |
| WO2007140658A1 (en) | 2007-12-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100571035C (en) | The method of plane capacitance sensor and the environmental change of detection windshield | |
| KR101122686B1 (en) | A device and method for detecting the environment change of windshield | |
| US11850824B2 (en) | Moisture sensor and/or defogger with bayesian improvements, and related methods | |
| CN2765181Y (en) | Sensor for automatic rain brush system | |
| CN2922285Y (en) | Planar condenser sensor | |
| US7504957B2 (en) | Light sensor embedded on printed circuit board | |
| US7830267B2 (en) | Rain sensor embedded on printed circuit board | |
| US8009053B2 (en) | Rain sensor with fractal capacitor(s) | |
| US10173579B2 (en) | Multi-mode moisture sensor and/or defogger, and related methods | |
| US8634988B2 (en) | Time, space, and/or wavelength multiplexed capacitive light sensor, and related methods | |
| CA2631843C (en) | Rain sensor with fractal capacitor(s) | |
| JP2009505038A (en) | Window with capacitive rain detector | |
| CN101283281A (en) | Sealed capacitive rain sensor | |
| CN102395463B (en) | Composite panel having integrated rain sensor | |
| CN1217204C (en) | Plane capacity type automatic wiper system intelligent sensor for automobile glass | |
| CN209795124U (en) | Automobile glass with heating and capacitance switch | |
| CN209290130U (en) | With rain, the windshield glass of mist amount detection function and containing the automobile of the windshield | |
| KR20210036971A (en) | Glazing unit | |
| Choi | Rain sensor with stacked light waveguide having tilted air gap | |
| CN109552010A (en) | With rain, the windshield glass of mist amount detection function and containing the automobile of the windshield |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| EE01 | Entry into force of recordation of patent licensing contract |
Assignee: Autoeasy Electronic Technology Co.,Ltd. Assignor: Sun Tengchen Contract record no.: 2011110000007 Denomination of invention: Plane capacitance sensor and method for detecting environmental change of motorcar glass Granted publication date: 20091216 License type: Exclusive License Open date: 20071212 Record date: 20110125 |
|
| ASS | Succession or assignment of patent right |
Owner name: BEIJING AUTOEASY ELECTRONIC TECHNOLOGY CO., LTD. Free format text: FORMER OWNER: SUN TENGCHEN Effective date: 20120717 |
|
| C41 | Transfer of patent application or patent right or utility model | ||
| COR | Change of bibliographic data |
Free format text: CORRECT: ADDRESS; FROM: 100044 HAIDIAN, BEIJING TO: 100176 DAXING, BEIJING |
|
| TR01 | Transfer of patent right |
Effective date of registration: 20120717 Address after: 100176, Beijing economic and Technological Development Zone, Rongchang, Daxing District East Street, No. 5, building 6, 7 floor Patentee after: Autoeasy Electronic Technology Co.,Ltd. Address before: 100044 Beijing City, Haidian District Xizhimen North Street No. 47 and building 2 times 3-363 Patentee before: Sun Tengchen |
|
| PE01 | Entry into force of the registration of the contract for pledge of patent right |
Denomination of invention: Plane capacitance sensor and method for detecting environmental change of motorcar glass Effective date of registration: 20180508 Granted publication date: 20091216 Pledgee: Huaxia Bank Beijing branch, Limited by Share Ltd. Pledgor: Autoeasy Electronic Technology Co.,Ltd. Registration number: 2018990000316 |
|
| PE01 | Entry into force of the registration of the contract for pledge of patent right | ||
| PC01 | Cancellation of the registration of the contract for pledge of patent right |
Date of cancellation: 20190819 Granted publication date: 20091216 Pledgee: Huaxia Bank Beijing branch, Limited by Share Ltd. Pledgor: Autoeasy Electronic Technology Co.,Ltd. Registration number: 2018990000316 |
|
| PC01 | Cancellation of the registration of the contract for pledge of patent right | ||
| PE01 | Entry into force of the registration of the contract for pledge of patent right |
Denomination of invention: Plane capacitance sensor and method for detecting environmental change of motorcar glass Effective date of registration: 20190823 Granted publication date: 20091216 Pledgee: Huaxia Bank Beijing branch, Limited by Share Ltd. Pledgor: Autoeasy Electronic Technology Co.,Ltd. Registration number: Y2019990000130 |
|
| PE01 | Entry into force of the registration of the contract for pledge of patent right | ||
| PC01 | Cancellation of the registration of the contract for pledge of patent right |
Date of cancellation: 20231225 Granted publication date: 20091216 Pledgee: Huaxia Bank Beijing branch, Limited by Share Ltd. Pledgor: Autoeasy Electronic Technology Co.,Ltd. Registration number: Y2019990000130 |
|
| PC01 | Cancellation of the registration of the contract for pledge of patent right |