METHOD AND DEVICE FOR DETECTING RAIN ON A WINDSHIELD

• US 20130145839A1
• Filed: 12/12/2012
• Published: 06/13/2013
• Est. Priority Date: 12/12/2011
• Status: Active Grant

• Current Assignee: Hella KGaA Hueck & Company
• Original Assignee: Hella KGaA Hueck & Company
• Inventors: NIEMANN, Thomas, PALLOKS, Jrgen, LDTKE, Olaf, SCHLARMANN, Almut, CZSICH, Cevin, STRMANN, Jrg
• Granted Patent: US 9,322,952 B2
• Time in Patent Office: Days
• US Class Current: 73/170.17
• CPC Class Codes: B60S 1/0491 Additional elements being fixed on wipers or parts of wipers not otherwise provided for, e.g. covers, antennae or lights
• CPC Class Codes: B60S 1/0859 Other types of detection of rain, e.g. by measuring friction or rain drop impact
• CPC Class Codes: G01N 2291/02809 Concentration of a compound, e.g. measured by a surface mass change
• CPC Class Codes: G01N 29/2437 Piezoelectric probes
• CPC Class Codes: G01W 1/14 Rainfall or precipitation gauges measuring volume in general G01F

Abstract

In a method for detecting rain on a windshield, whose degree of wetting is determined with at least one sensor value, it is provided that the sensor value is determined piezoelectrically, wherein vibrations on the windshield are detected, which change depending on the degree of wetting or raindrops hitting the windshield. As a result, the entire windshield serves as a detection surface, thereby yielding a high accuracy.

Claims

1. A method for detecting rain on a windshield, whose degree of wetting is determined with at least one sensor value:

wherein the sensor value is determined piezoelectrically, wherein vibrations on the windshield are detected, which change depending on the degree of wetting or raindrops hitting the windshield, and that the vibrations on the windshield are detected via at least one wiper blade of a windshield wiper system and its coupling to the windshield.

2. The method according to claim 1, wherein a distribution profile is established for the degree of wetting given at least two sensor values detected at locations spaced apart from each other.

3. The method according to claim 1, wherein at least one additional sensor value is detected, wherein an optical signal is sent out, the optical signal is reflected on the windshield in a predetermined detection range, the reflected optical signal is detected, and a differential value is derived from the transmitted and detected signal, based upon which the degree of wetting is determined for the windshield.

4. The method according to claim 3, wherein, when the windshield wiper system is activated for the first time, the area of the windshield in which the optical signal is reflected is wiped especially slowly, and any water located on the windshield is determined and quantified with the optical signal in the wiping process.

5. A device for detecting rain on a windshield with at least one rain sensor, which is allocated to a windshield wiper system of the windshield,

wherein the rain sensor exhibits at least one piezo element, and that

the windshield wiper system has at least one wiper blade, and the wiper blade has the piezo element of the rain sensor.

6. The device according to claim 5, wherein the piezo element is designed as a piezoelectric line, which detects the wiper blade over its entire longitudinal expansion.

7. The device according to claim 5, wherein the rain sensor exhibits at least one additional, optoelectric sensor unit.

8. A motor vehicle, exhibiting a device according to claim 5.