Device for operating a windshield wiper

• US 6,175,205 B1
• Filed: 12/20/1999
• Issued: 01/16/2001
• Est. Priority Date: 04/04/1997
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Kroeninger, Mario, Michenfelder, Gebhard, Blitzke, Henry, Buehren, Harald
• Primary Examiner(s): IP, SHIK LUEN PAUL
• Application Number:
  US09/402,413
• Time in Patent Office: 393 Days
• Field of Search: 318/440-479, 318/DIG.2, 318/483, 318/643, 388/907.5, 388/916, 152/501.2, 152/501.3, 152/501.7, 152/500.01, 340/602, 340/604, 250/574, 250/575
• US Class Current: 318/444
• CPC Class Codes: B60S 1/0818 including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like
• CPC Class Codes: Y10S 318/02 Windshield wiper controls

Abstract

A device (10) for operating a windshield wiper (12) is proposed, with a moisture sensor (22) for detecting the wetness of a window that in addition to detecting rain and droplets also detects fog and drizzle. The measured values (Us) of the moisture sensor (22) are allocated incremental values (Ink) by the control unit (16). The difference between two successive incremental values (Ink) is to be added, with a sign (+ or −), in the memory (28) to a sum (Σ) of differences formed previously in the same way, and when a threshold (S) is reached by the sum (Σ) stored in the memory (28), the control unit (16) trips a wiper operating mode.

Claims

1. A device for operating a windshield wiper, comprising a wiper motor;

a control unit with a memory;

a moisture sensor for detecting a wetness of a window, whose measured values vary as the wetness increases, said control unit allocating incremental values to the measured values, to form a mean value of at least two successive measured value as the incremental value, with respective difference between two successive incremental values to be added with a plus sign or a minus sign in said memory to a sum of differences formed previously in a same way, said control unit tripping a wiper operating mode when a threshold is reached by said sum stored in said memory.

2. A device as defined in claim 1, wherein in said control unit, an arbitrarily predeterminable first limit value and a second limit value of the sum are defined, and the first limit value is allocated to the measured value of said moisture sensor for a dry or clean window.

3. A device as defined in claim 2, wherein said first limit value is writable into said memory as a starting value for said sum.

4. A device as defined in claim 2, wherein said threshold is located in a range between said first and second limit values.

5. A device as defined in claim 3, wherein said threshold is embodied variably.

6. A device as defined in claim 1, wherein said control unit has means for temperature compensation which correct said sum by means of correction increments.

7. A device as defined in claim 6, wherein said means for temperature compensation is a program controller.

8. A device as defined in claim 1, and further comprising means for temperature detection which is formed as a temperature sensor.

9. A device as defined in claim 1, wherein said control unit includes an incremental value transducer, a differential value former, means for temperature compensation, and an evaluation stage.

10. A method of operating at least one windshield wiper having a wiper motor, a control unit with a memory and a moisture sensor for detecting a wetness of a window whose measured values vary as the wetness increases, the method comprising the steps of allocating incremental values to the measured values by the control unit;

forming a respective mean value of at least two successive measured values as an incremental value;

adding a difference between successive incremental values with a plus sign or a minus sign in the memory to a sum of differences formed previously in a same way; and

when a threshold is reached by the sum stored in the memory, tripping a wiper operating mode by the control unit.

11. A method as defined in claim 10;

and further comprising writing in the control unit an arbitrarily predeterminable first limit value into the memory as a starting value for the sum.

12. A method as defined in claim 10;

and further comprising defining in the control unit an arbitrarily predeterminable second limit of the sum; and

upon attainment of the second limit value and with further-increasing moisture, defining the sum as a value of the second limit value.

13. A method as defined in claim 10;

and further comprising varying a temperature of the moisture sensor by rising the temperature; and

imposing by the control unit correction increments on the sum by adding them to the sum.