US5140233A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control of windshield wiper by integration and differentiation of sensor signal
Assignee: Mannesmann VDO AG
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Filing: 1990-11-30
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Granted: 1992-08-18
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Expires: 2010-11-30
Abstract
Abstract A method and a system for controlling a windshield wiper, particularly on a motor vehicle, provides that the windshield wiper is automatically activated as a function of the intensity of rain. A frequency-limited variation of the signal of a sensor serves as a measure of the intensity of the rain.
Inventors
- 👤 Werner Wallrafen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:10
CPC Classifications
B; B60; B60S; B60S1/00; B60S1/02; B60S1/04; B60S1/06; B60S1/08; B60S1/0818; G; G01; G01N; G01N27/00; G01N27/02; G01N27/22; G01N27/223; Y; Y10; Y10S; Y10S15/00; Y10S15/15; Y10S318/00; Y10S318/02
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
120 words
A method for controlling a windshield wiper, suitable for a motor vehicle, in which the windshield wiper is automatically turned on as a function of the intensity of the rain, the method comprising the steps of sensing the presence of rain with an electrically activated sensor; employing a frequency-limited variation of a signal of the sensor to serve as a measure of the rain; and wherein said employing step includes: integrating the value of the sensor signal; differentiating a result obtained from the step of integrating, the differentiating being done with a large time constant in order to compensate for the evaporation of water; and activating the windshield wiper when a result of the differentiating step exceeds a threshold value.
Claim 2
Independent Claim
120 words
A method for controlling a windshield wiper, suitable for a motor vehicle, in which the windshield wiper is automatically turned on as a function of the intensity of the rain, the method comprising the steps of sensing the presence of rain with an electrically activated sensor; employing a frequency-limited variation of a signal of the sensor to serve as a measure of the rain; and wherein said employing step includes: integrating the value of the sensor signal; differentiating a result obtained from the step of integrating, the differentiating being done with a large time constant in order to compensate for the evaporation of water; and activating the windshield wiper when a result of the differentiating step exceeds a threshold value.
Claim 3
Dependent Claim
38 words
A method according to claim 1, further comprising the steps, prior to said integrating step, of conducting the sensor signal via a bandpass filter to obtain a band-limited signal; and forming the effective value of the band-limited signal.
Claim 4
Dependent Claim
43 words
A method according to claim 1, further comprising the steps, prior to said integrating step, of forming an average value of the sensor signal; and calculating the variance or standard deviation of the instantaneous signal from an average value of the sensor signal.
Claim 5
Dependent Claim
15 words
A method according to claim 1, further comprising restarting the integration after each wiping process.
Claim 6
Dependent Claim
35 words
A method according to claim 4, further comprising differentiating a result obtained from the step of integrating, the differentiating being done with a large time constant in order to compensate for the evaporation of water.
Claim 7
Dependent Claim
22 words
A method according to claim 3, further comprising only values of the variance which exceed a threshold value are evaluated and integrated.
Claim 8
Dependent Claim
41 words
A method according to claim 3, wherein a variation which is less than a predetermined threshold value is detected as a dry windshield and that the sensor signal present at this time serves as comparison value for activating the windshield wiper.
Claim 9
Dependent Claim
20 words
A method according to claim 7, further comprising activating the windshield wiper when the sensor signal exceeds a comparison value.
Claim 10
Independent Claim
89 words
A system for controlling a windshield wiper, suitable for a motor vehicle, in which the windshield wiper is automatically turned on as a function of the intensity of the rain, comprising an analog-to-digital converter, and a microcomputer; and a rain sensor, the sensor being connected via the analog-to-digital converter to the microcomputer; and the microcomputer is operated in accordance with a program to provide for integration of a signal of the sensor followed by differentiation of a result of the integration to provide said function of the rain intensity.
Claim 11
Independent Claim
89 words
A system for controlling a windshield wiper, suitable for a motor vehicle, in which the windshield wiper is automatically turned on as a function of the intensity of the rain, comprising an analog-to-digital converter, and a microcomputer; and a rain sensor, the sensor being connected via the analog-to-digital converter to the microcomputer; and the microcomputer is operated in accordance with a program to provide for integration of a signal of the sensor followed by differentiation of a result of the integration to provide said function of the rain intensity.
Claim 12
Dependent Claim
14 words
A system according to claim 9, wherein the sensor is a capacitive wetness sensor.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-08-18 | 1996-02-17 | 1996-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-18 | 2000-02-17 | 2000-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-18 | 2004-02-17 | 2004-08-18 | $7700.00 | Window Closed / Lapsed |