Wiper control system

• US 7,235,944 B2
• Filed: 07/05/2005
• Issued: 06/26/2007
• Est. Priority Date: 07/07/2004
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Morishita, Taiji
• Primary Examiner(s): Masih; Karen
• Application Number:
  US11/172,923
• Publication Number:
  US 20060006826A1
• Time in Patent Office: 721 Days
• Field of Search: 318/483, 318/466, 318/467, 318/468, 388/933, 388/929, 312/DIG.2, 312/445, 312/456, 312/480, 312/482
• US Class Current: 318/483
• 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: B60S 1/0896 including control systems responsive to a vehicle driving condition, e.g. speed

Abstract

A wiper control system for detecting an amount of raindrops landed on a windshield of a vehicle and driving a wipe operation of a wiper to wipe the landed raindrops. The wiper control system includes raindrop sensing means, average landed raindrop amount calculation means, vehicle acceleration sensing means, and wipe operation mode selection means. The raindrop sensing means is capable of detecting the amount of landed raindrops for each of a plurality of wipe cycles of the wiper. The average landed raindrop amount calculation means calculates an average value of the amount of landed raindrops for the plurality of wipe cycles. The vehicle acceleration sensing means detects an acceleration of the vehicle. The wipe operation mode selection means selects a wipe operation mode based on the acceleration of the vehicle and any one of the amount of landed raindrops and the average amount of landed raindrops.

Claims

1. A wiper control system for detecting an amount of raindrops landed on a windshield of a vehicle and driving a wipe operation of a wiper to wipe the landed raindrops, the wiper control system comprising:

raindrop sensing means capable of detecting the amount of landed raindrops for each of a plurality of wipe cycles of the wiper;

average landed raindrop amount calculation means for calculating an average value of the amount of landed raindrops for the plurality of wipe cycles;

vehicle acceleration sensing means for determining an acceleration of the vehicle;

wipe operation mode selection means for selecting a wipe operation mode, wherein the wipe operation mode selection means selects the wipe operation mode of the wiper based on the acceleration of the vehicle and one of the amount of landed raindrops and the average amount of landed raindrops;

determination means for determining based on the vehicle acceleration whether or not to implement the wipe operation mode selection based on the average amount of landed raindrops, wherein

the wipe operation mode selection means selects the wipe operation mode based on the average amount of landed raindrops when it is determined by the determination means that the wipe operation mode selection is implemented based on the average amount of landed raindrops and the wipe operation mode selection means selects the wipe operation mode based on any one of the amount of landed raindrops and the vehicle acceleration when it is not determined that the wipe operation mode selection based on the average amount of landed raindrops is implemented.

2. The wiper control system according to claim 1, wherein

the determination means includes provisional wipe operation mode selection means for selecting a provisional wipe operation mode based on the amount of landed raindrops,

the wipe operation mode selection means selects the provisional wipe operation mode as the wipe operation mode when the determination means does not determine the implementation of the wipe operation mode selection based on the average amount of landed raindrops.

3. The wiper control system according to claim 1, wherein

the determination means includes:

acceleration criterion value setting means for setting an acceleration criterion value for determining the degree of acceleration or deceleration of the vehicle; and

comparison means for comparing the vehicle acceleration with the acceleration criterion value, wherein the acceleration criterion value setting means varies the acceleration criterion value in accordance with the vehicle speed.

4. The wiper control system according to claim 3, further comprising:

vehicle speed zone setting means for dividing the range of vehicle speed, at which the vehicle can run, into a plurality of zones, wherein

the acceleration criterion value setting means includes upper acceleration limit criterion value setting means for determining whether the vehicle accelerates or not for each zone,

the plurality of zones are classified at least into an extremely low speed zone in which the vehicle speed is extremely low including a stop of the vehicle and the other zones except for the extremely low speed zone, and

an upper acceleration limit criterion value in the extremely low speed zone is set lower than those in the other zones.

5. The wiper control system according to claim 3, further comprising:

vehicle speed zone setting means for dividing the range of vehicle speed, at which the vehicle can run, into a plurality of zones, wherein

the acceleration criterion value setting means includes lower acceleration limit criterion value setting means for determining for each of the zones whether the vehicle decelerates or not so that the lower acceleration limit criterion value is set lower in a zone with a higher vehicle speed.

6. A wiper control system for detecting an amount of raindrops landed on a windshield of a vehicle and driving a wipe operation of a wiper to wipe the landed raindrops, the wiper control system comprising:

raindrop sensing means capable of detecting the amount of landed raindrops for each of a plurality of wipe cycles of the wiper;

average landed raindrop amount calculation means for calculating an average value of the amount of landed raindrops for the plurality of wipe cycles;

vehicle acceleration sensing means for determining an acceleration of the vehicle;

wipe operation mode selection means for selecting a wipe operation mode, wherein the wipe operation mode selection means selects the wipe operation mode of the wiper based on the acceleration of the vehicle and one of the amount of landed raindrops and the average amount of landed raindrops; and

wherein the wipe operation mode selection means selects the wipe operation mode based on a change between an earlier average amount of landed raindrops and a later average amount of landed raindrops calculated in the order of wipe cycles in the case where the wipe operation mode is selected based on the average amount of landed raindrops.

7. A wiper control system for detecting an amount of raindrops landed on a windshield of a vehicle and driving a wipe operation of a wiper to wipe the landed raindrops, the wiper control system comprising:

raindrop sensing means capable of detecting the amount of landed raindrops for each of a plurality of wipe cycles of the wiper;

average landed raindrop amount calculation means for calculating an average value of the amount of landed raindrops for the plurality of wipe cycles;

vehicle acceleration sensing means for determining an acceleration of the vehicle;

wipe operation mode selection means for selecting a wipe operation mode, wherein the wipe operation mode selection means selects the wipe operation mode of the wiper based on the acceleration of the vehicle and one of the amount of landed raindrops and the average amount of landed raindrops; and

wherein the average landed raindrop amount calculation means includes;

storage means for storing the amounts of landed raindrops in the order of wipe cycles; and

sample number setting means for setting the number of samples as a parameter for averaging the amounts of landed raindrops, wherein an average amount of landed raindrops is calculated from the latest amount of landed raindrops detected based on the number of samples and the previous amounts of landed raindrops except for the latest amount of landed raindrops.

8. The wiper control system according to claim 7, further comprising:

change criterion value setting means for setting a criterion value to be compared with a change in the average amount of landed raindrops for selecting the wipe operation mode; and

acquisition means for acquiring switching information for switching to a change criterion value required by the driver, wherein

the change criterion value setting means changes the change criterion value based on any one of the switching information and the vehicle speed.

9. A wiper control method for detecting an amount of raindrops landed on a windshield of a vehicle and driving a wipe operation of a wiper to wipe the landed raindrops, the wiper control method comprising:

detecting the amount of landed raindrops for each of the plurality of wipe cycles of the wiper;

calculating an average value of the amount of landed raindrops for the plurality of wipe cycles;

determining an acceleration of the vehicle;

selecting a wipe operation mode, wherein selection of the wipe operation mode of the wiper is based on the acceleration of the vehicle and one of the amount of landed raindrops and the average amount of landed raindrops; and

determining based on the vehicle acceleration whether or not to implement the wipe operation mode selection based on the average amount of landed raindrops;

wherein the wipe operation mode is selected based on the average amount of landed raindrops when it is determined that the wipe operation mode selection is implemented based on the average amount of landed raindrops and the wipe operation mode is selected based on any one of the amount of landed raindrops and the vehicle acceleration when it is not determined that the wipe operation mode selection based on the average amount of landed raindrops is implemented.

10. The method according to claim 9, wherein

determining whether or not to implement the wipe operation mode selection includes selecting a provisional wipe operation mode based on the amount of landed raindrops, wherein

the provisional wipe operation mode is selected as the wipe operation mode when the implementation of the wipe operation mode selection based on the average amount of landed raindrops is not determined.

11. The method according to claim 9, wherein

determining whether or not to implement the wipe operation mode selection includes:

setting an acceleration criterion value for determining the degree of acceleration or deceleration of the vehicle; and

comparing the vehicle acceleration with the acceleration criterion value, wherein the acceleration criterion value is varied accordance with the vehicle speed.

12. The method according to claim 11, further comprising:

dividing the range of vehicle speed, at which the vehicle can run, into a plurality of zones, wherein setting the acceleration criterion value includes determining whether the vehicle accelerates or not for each zone,

the plurality of zones are classified at least into an extremely low speed zone in which the vehicle speed is extremely low including a stop of the vehicle and the other zones except for the extremely low speed zone, and

an upper acceleration limit criterion value in the extremely low speed zone is set lower than those in the other zones.

13. The method according to claim 11, further comprising:

dividing the range of vehicle speed, at which the vehicle can run, into a plurality of zones, wherein setting the acceleration criterion value includes determining for each of the zones whether the vehicle decelerates or not so that a lower acceleration limit criterion value is set lower in a zone with a higher vehicle speed.

14. A wiper control method for detecting an amount of raindrops landed on a windshield of a vehicle and driving a wipe operation of a wiper to wipe the landed raindrops, the wiper control method comprising:

detecting the amount of landed raindrops for each of a plurality of wipe cycles of the wiper;

calculating an average value of the amount of landed raindrops for the plurality of wipe cycles;

determining an acceleration of the vehicle; and

selecting a wipe operation mode, wherein selection of the wipe operation mode of the wiper is based on the acceleration of the vehicle and one of the amount of landed raindrops and the average amount of landed raindrops; and

wherein the wipe operation mode is selected based on a change between an earlier average amount of landed raindrops and a later average amount of landed raindrops calculated in the order of wipe cycles in the case where the wipe operation mode is selected based on the average amount of landed raindrops.

15. A wiper control method for detecting an amount of raindrops landed on a windshield of a vehicle and driving a wipe operation of a wiper to wipe the landed raindrops, the wiper control method comprising:

detecting the amount of landed raindrops for each of the plurality of wipe cycles of the wiper;

calculating an average value of the amount of landed raindrops for the plurality of wipe cycles;

determining an acceleration of the vehicle;

selecting a wipe operation mode, wherein selection of the wipe operation mode of the wiper is based on the acceleration of the vehicle and one of the amount of landed raindrops and the average amount of landed raindrops; and

wherein calculating the average value of the amount of landed raindrops for the plurality of wipe cycles includes storing the amounts of landed raindrops in the order of wipe cycles; and

setting the number of samples as a parameter for averaging the amounts of landed raindrops, wherein an average amount of landed raindrops is calculated from the latest amount of landed raindrops detected based on the number of samples and the previous amounts of landed raindrops except for the latest amount of landed raindrops.

16. The method according to claim 15, further comprising:

setting a criterion value to be compared with a change in the average amount of landed raindrops for selecting the wipe operation mode; and

acquiring switching information for switching to a change criterion value required by the driver, wherein

the change criterion value is changed based on any one of the switching information and the vehicle speed.