JP5812343B2 - Wiper control device - Google Patents

Description

  The present invention relates to a wiper control device that automatically controls a time interval or an operation speed (hereinafter referred to as “wiping mode”) of a wiper wiping operation.

2. Description of the Related Art Conventionally, a wiper control device that automatically controls a wiper wiping mode based on an output signal of a raindrop sensor that detects raindrops attached to a windshield of a vehicle is known. The wiper control device switches the wiping mode to an intermittent mode, an LO continuous mode, an HI continuous mode, or the like.
In the wiper control device described in Patent Literature 1, when the state in which the pause time during the wiping operation is shorter than the predetermined time in the intermittent mode continues for a preset number of times of wiping, the wiping mode is continuously LO from the intermittent mode. Switch to mode. Further, the wiper control device sets the wiping mode to LO continuous when the state in which the amount of raindrop detected during the wiper wiping operation in the LO continuous mode of the wiper falls below the mode-down threshold continues for a preset number of times of wiping. Switching from mode to intermittent mode. Thereby, the wiper control device is improving the stability of wiping.

JP-A-6-328998

However, in Patent Document 1, since switching of the wiping mode is determined when a predetermined state in wiper wiping continues for a predetermined number of wiping times, the wiping mode can be switched while the number of wiping times has elapsed. Can not. For this reason, we are anxious about the responsiveness of the wiping mode switching with respect to the change of rainfall getting worse.
Moreover, in patent document 1, the rest time of the wiping operation | movement in intermittent mode is changed based on the amount of raindrops during one wiper wiping operation | movement. For this reason, the suspending time of the wiping operation changes due to accidental adhesion of raindrops due to so-called fluttering rain having a large raindrop diameter, which may deteriorate the wiping stability.
The present invention has been made in view of the above problems, and an object thereof is to provide a wiper control device capable of improving the responsiveness and stability of the wiping mode.

According to the first aspect of the invention, the raindrop sensor outputs a signal corresponding to the raindrop attached to the raindrop detection region. Based on the output signal of the raindrop sensor, the raindrop amount detection means adheres to the raindrop detection area between a predetermined time when the wiper performs one reciprocating operation and a predetermined time when the wiper performs one reciprocating operation next time . Detect the amount of raindrops. Based on the output signal of the raindrop sensor, the raindrop amount detection means detects raindrops in the raindrop detection area between a predetermined time when the wiper performs one reciprocating operation and a predetermined time when the wiper performs one reciprocating operation next. It is detected whether or not it has adhered. The detection rate calculation means calculates, as a rain detection rate, the number of times that the raindrop detection means detects raindrops relative to the number of wiper wiping operations from the start of control or when the wiping mode is switched . The determination number setting means sets a smaller number of determinations for use in wiping mode switching determination as the rain detection rate is larger, and sets a larger number of determinations as the rain detection rate is smaller. The wiping mode switching means switches to the wiping mode with a short time interval when the raindrop amount is equal to or greater than the mode-up threshold for the number of determinations set by the determination number setting means. Further, the wiping mode switching means switches to the wiping mode with a long time interval when the raindrop amount is equal to or less than the mode-down threshold for the number of determinations set by the determination number setting means.

In general, the raindrop detection area where the raindrop sensor detects raindrops is limited to a narrow area of the front windshield. For this reason, when there is little rain, a raindrop may not adhere to a raindrop detection area | region during wiper wiping operation, and a raindrop sensor may not detect a raindrop. For this reason, when the rain detection rate calculated by the detection rate calculation means is small, the determination number setting means sets a large number of determinations. Therefore, the wiper control device can increase the stability of the wiping mode by switching the wiping mode by the wiping mode switching means using the set number of determinations. As a result, the wiping mode is maintained even when the amount of raindrops detected by the raindrop sensor accidentally increases due to so-called fluttering rain.
On the other hand, when there is a lot of rain, raindrops adhere to the raindrop detection area with high probability during the wiper wiping operation, and the raindrop sensor detects the raindrop with high probability. For this reason, when the rain detection rate calculated by the detection rate calculating means is large, the determination number setting means sets the determination number to be small. Even in such a setting, since the rain detection rate is large, the wiper control device can maintain the stability of the wiping mode. Further, the wiper control device can improve the responsiveness of the wiping mode by switching the wiping mode with a small number of determinations by the wiping mode switching means. As a result, the wiper control device can quickly increase the mode as the rainfall increases. Further, when a vehicle to which the wiper control device is applied enters the tunnel, the wiper control device can quickly be down. Therefore, the wiping feeling of the wiper can be enhanced.

1 is a schematic diagram of a vehicle to which a wiper control device according to a first embodiment of the present invention is applied. It is a lineblock diagram of the wiper control device by a 1st embodiment of the present invention. It is a time chart of the wiper automatic control processing which the wiper control device by a 1st embodiment of the present invention performs. It is a time chart of the wiper automatic control processing which the wiper control device by a 1st embodiment of the present invention performs. It is a time chart of the wiper automatic control processing which the wiper control device by a 1st embodiment of the present invention performs. It is a flowchart of the wiper automatic control process which the wiper control apparatus by 1st Embodiment of this invention performs. It is a flowchart of the wiper automatic control process which the wiper control apparatus of a reference example performs.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
A wiper control device according to a first embodiment of the present invention is shown in FIGS. The rain sensor 1 as the wiper control device of this embodiment controls the wiping mode of the wiper 3 that wipes the front windshield 2 of the vehicle.
As shown in FIGS. 1 and 2, the rain sensor 1 is attached to a surface on the vehicle interior side of the wiper wiping region of the front windshield 2 of the vehicle. The raindrop sensor 5 included in the rain sensor 1 outputs a voltage signal corresponding to the raindrop attached to the raindrop detection region 4 of the front windshield 2 by an optical method or a capacitance method. The voltage signal output from the raindrop sensor 5 varies depending on the amount of raindrops attached to the raindrop detection region 4.

The rain sensor 1 includes a microcomputer 6 that controls the wiping mode of the wiper 3 based on the output signal of the raindrop sensor 5. The output signal of the rain sensor 1 is transmitted to an electronic control unit (ECU) 7 by an in-vehicle LAN. The ECU 7 supplies current to the motor 8 that drives the wiper 3 in accordance with the output signal of the rain sensor 1. Thereby, the motor 8 drives the wiper 3 in the wiping mode according to the rainfall.
The microcomputer 6 functions as the raindrop amount detection means 11, the raindrop detection means 12, the detection rate calculation means 13, the determination frequency setting means 14, the wiping mode switching means 15 and the like by the CPU executing a program stored in the memory. To do.

The raindrop amount detection means 11 detects the amount of raindrops attached to the raindrop detection area 4 during the wiper wiping operation based on the output signal of the raindrop sensor 5.
The memory of the microcomputer 6 stores a predetermined threshold that can determine whether or not raindrops have adhered to the raindrop detection area 4. When the output signal of the raindrop sensor 5 is larger than the threshold value, the raindrop detection means 12 determines that raindrops have adhered to the raindrop detection area 4 during the wiper wiping operation. Moreover, when the output signal of the raindrop sensor 5 is smaller than the threshold value, the raindrop detection means 12 determines that no raindrop is attached to the raindrop detection area 4 during the wiper wiping operation.

The detection rate calculation means 13 calculates a rain detection rate. B = Cr / Cw where B is the rain detection rate, Cw is the number of wiper wiping operations, and Cr is the number of times the raindrop detection means 12 has detected a raindrop.
The determination number setting unit 14 sets the number of determinations used by the wiping mode switching unit 15, which will be described later, for switching determination of the wiping mode. The determination frequency setting means 14 sets the determination frequency smaller as the rain detection rate is higher, and sets the determination frequency higher as the rain detection rate is lower. The number of determinations set by the determination number setting unit 14 can be arbitrarily set. In the present embodiment, as an example, the determination count setting unit 14 sets the determination count when the rain detection rate is 50% or more to 2 times, and the determination count when the rain detection rate is less than 50% and 33% or more. Is set to 3 times, and the number of determinations when the rain detection rate is less than 33% is set to 4 times.

  The wiping mode switching unit 15 is mode-up when the raindrop amount is equal to or greater than the mode-up threshold for the number of determinations set by the determination number setting unit 14, and the raindrop amount is equal to or less than the mode-down threshold for the number of determinations. When the mode is down, the wiping mode is maintained otherwise. Note that the mode-up means switching the wiping mode to a wiping mode in which the wiper wiping operation pause time is short, or increasing the wiper wiping operation speed. Mode down means switching the wiping mode to a wiping mode with a long pause time of the wiper wiping operation, or slowing the wiper wiping operation speed.

Next, the wiper automatic control process executed by the rain sensor 1 will be described based on the time charts of FIGS.
The wiper automatic control process when there is a lot of rain and the detection rate of the rain sensor 1 is high is shown in FIG.
The wiper automatic control process has been continuously executed before time t1 in FIG. 3, and the detection rate detected by the detection rate calculation means 13 has changed by 50% or more from time t1 to time t7.
The detection rate calculating means 13 ends the subsequent wiper wiping operation based on a signal output from the raindrop sensor 5 according to the amount of raindrops attached to the raindrop detection area 4 between the wiper wiping operation and the wiper wiping operation. Sometimes calculate the detection rate. For example, the detection rate calculation means 13 calculates the detection rate at time t2 based on a signal output from the raindrop sensor 5 during the wiper wiping operation between times t1 and t2.

In the present embodiment, when the rain detection rate is 50% or more, the determination count setting unit 14 sets the determination count to two. For this reason, when it is continuously detected twice at time t6 and t7 that the amount of raindrops is greater than or equal to the mode-up threshold, the wiping mode switching means 15 changes the wiping mode from intermittent mode (INT) to LO continuous at time t7. Mode up to mode.
The rain sensor can improve the responsiveness of switching the wiping mode by performing the wiping mode switching determination with a small number of determination times during heavy rain. Thereby, the wiping feeling of the wiper is improved.
When the wiping mode is switched, the detection rate calculation means 13 sets the detection rate to 0% and calculates the detection rate after time t8. At that time, the prohibition means 18 (see FIG. 2) prohibits switching of the wiping mode for a certain time until the detection rate is stabilized.

On the other hand, FIG. 4 shows the wiper automatic control process when the rainfall is low and the detection rate of the rain sensor 1 is low.
The wiper automatic control process has been continuously executed before time t21 in FIG. 4, and the detection rate detected by the detection rate calculation means 13 has changed at 33% or less from time t21 to t30.
In the present embodiment, when the rain detection rate is 33% or less, the determination number setting unit 14 sets the determination number to four. For this reason, it is continuously detected twice that the raindrop amount detected by the raindrop amount detection means 11 at the times t26 and t27 is equal to or greater than the mode-up threshold, but the wiping mode switching means 15 sets the wiping mode to the intermittent mode ( INT).
The rain sensor 1 makes it possible to prevent the wiping mode from being mode-up due to accidental raindrops such as dripping rain, etc., by performing switching determination of the wiping mode with a large number of determinations when there is little rain. Further, the rain sensor 1 can prevent the wiping mode from immediately going down even when raindrops do not adhere to the raindrop detection area 4 during a plurality of wiper wiping operations during light rain. Thereby, the rain sensor 1 improves the stability of the wiping mode.

FIG. 5 shows an automatic wiper control process when the vehicle with the rain sensor 1 attached enters the tunnel when there is a lot of rain.
The wiper automatic control process has been continuously executed before time t31 in FIG. 5, and the detection rate detected by the detection rate calculation means 13 has changed by 50% or more from time t31 to t38.
When the rain detection rate is 50% or more, the determination number setting unit 14 sets the determination number to two.
If the vehicle enters the tunnel halfway between times t35 and t36, raindrops are not detected after time 37. For this reason, if it is detected twice continuously that the amount of raindrops is below the mode-down threshold at times t37 and t38, the wiping mode switching means 15 changes the wiping mode from the intermittent mode (INT0.7S) at time t38. Mode down to (INT1.5S). At that time, the detection rate calculation means 13 sets the detection rate to 0%.
The rain sensor 1 can improve the mode-down response to a sudden decrease in rainfall when entering the tunnel. Thereby, the wiping feeling of the wiper is improved.

Next, the wiper automatic control process executed by the rain sensor 1 of the present embodiment will be described based on the flowchart of FIG.
The wiper automatic control process is executed when the automatic mode of the wiper switch is selected by the driver. First, in step S1 (hereinafter, “step” is omitted and represented by the symbol “S”), the rain detection rate of the detection rate calculating means 13 is set to 0%.
In S <b> 2, the rain detection rate B is calculated by the detection rate calculation means 13. The rain detection rate B is calculated from the number of times Cr that the raindrop detection means 12 has detected for the number of wiper wiping operations Cw from the start of the wiper automatic control process to the current time.

In S3, the raindrop amount detection means 11 detects the raindrop amount attached to the raindrop detection area 4 during the wiper wiping operation. It is assumed that the raindrop amount detected by the raindrop amount detection means 11 is A.
In S4, it is determined whether or not the raindrop amount A detected by the raindrop amount detection means 11 is equal to or greater than the mode-up threshold. When the raindrop amount A is smaller than the mode-up threshold (S4, NO), the process proceeds to S11.
In S11, it is determined whether or not the raindrop amount A is equal to or less than the mode-down threshold. When the raindrop amount A is larger than the mode-down threshold (S11, NO), the process proceeds to S2, and S3, S4, and S11 are repeated. During this time, the wiping mode is maintained.

In S4, when the raindrop amount A is greater than or equal to the mode-up threshold (S4, YES), the mode-up counter 16 (see FIG. 2) is incremented by 1, and the process proceeds to S5.
In S5, it is determined whether or not the detection rate B calculated in S2 is 50% or more, less than 50% and 33% or more, or less than 33%. When the detection rate B is 50% or more, the process proceeds to S6, and the determination number N used for mode-up switching determination is set to 2.
In S5, when the detection rate B is less than 50% and 33% or more, the process proceeds to S7, and the determination count N is set to 3. In S5, when the detection rate B is less than 33%, the process proceeds to S8, and the determination count N is set to 4. The processing from S5 to S8 corresponds to the processing by the determination number setting means 14.

When the determination number N is set in S6, S7, or S8, the process proceeds to S9, and it is determined whether or not the number stored in the mode up counter 16 is less than the determination number N. When the number of times of the mode up counter 16 is less than the determination number N (S9, NO), the process proceeds to S2, and S3 to S9 are repeated. During this time, the wiping mode is maintained. When the number of times of the mode up counter 16 reaches the determination number N in S9 (S9, YES), the process proceeds to S10 and the mode is increased. Note that the processes of S2-S6, S9, and S10 correspond to the process shown at time t7 in FIG.
When the wiping mode is switched, the process proceeds to S1, and the wiper automatic control process is repeatedly executed with the detection rate B set to 0%. However, after the detection rate B is set to 0%, switching of the wiping mode is prohibited by the prohibiting means 18 (see FIG. 2) for a predetermined time. Thereby, the stability of the wiping mode is ensured.

On the other hand, if it is determined in S11 that the raindrop amount is equal to or less than the mode-down threshold (S11, YES), the mode-down counter 17 (see FIG. 2) is incremented by 1, and the process proceeds to S12.
In S12, it is determined whether or not the detection rate B calculated in S2 is 50% or more, less than 50% and 33% or more, or less than 33%. When the detection rate B is 50% or more, the process proceeds to S13, and the determination count M used for mode down switching determination is set to 2.
In S12, when the detection rate B is less than 50% and 33% or more, the process proceeds to S14, and the determination count M is set to 3. In S12, when the detection rate B is less than 33%, the process proceeds to S15, and the determination count M is set to 4. The processing from S12 to S15 corresponds to the processing by the determination number setting means 14.

When the determination number M is set in S13, S14, or S15, the process proceeds to S16, and it is determined whether or not the number stored in the mode down counter 17 is less than the determination number M. When the number of times of the mode down counter 17 is less than the determination number M (S16, NO), the process repeats S2 to S4 and S11 to S16. During this time, the wiping mode is maintained. When the number of times of the mode down counter 17 reaches the determination number M in S16 (S16, YES), the process proceeds to S17 and the mode is down. Note that the processes of S2-S4, S11-S13, S16, and S17 correspond to the process shown at time t38 in FIG.
When the wiping mode is switched, the process proceeds to S1, and the wiper automatic control process is repeatedly executed with the detection rate B set to 0%.

The rain sensor 1 of this embodiment has the following effects.
(1) In this embodiment, when the rain detection rate is small, the possibility that raindrops will adhere to the raindrop detection area 4 of the front windshield 2 is small, so the determination count setting means 14 sets a large number of determinations. Therefore, even if raindrops do not adhere to the raindrop detection area 4 during the wiper wiping operation, the wiping mode does not immediately switch, so the rain sensor 1 improves the stability of the wiping mode during light rain. be able to.
In addition, even when the amount of raindrops detected by the raindrop sensor 5 is accidentally increased due to dripping rain, the wiping mode is maintained without immediately switching the wiping mode. Therefore, the rain sensor 1 can improve the stability of the wiping mode at the time of light rain.
(2) In this embodiment, when the rain detection rate calculated by the detection rate calculation means 13 is large, the determination number setting means 14 sets the determination number to be small. Even in such a setting, since there is a high possibility that raindrops can be detected when there is a lot of rain, the rain sensor 1 can maintain wiping stability.
Furthermore, the rain sensor 1 can improve the responsiveness of the wiping mode by switching the wiping mode with a small number of determinations by the wiping mode switching means 15. As a result, the rain sensor 1 can be promptly upgraded as the rainfall increases. Moreover, when the vehicle to which the rain sensor 1 is applied enters the tunnel, the rain sensor 1 can be quickly down.
(3) In this embodiment, when the wiping mode switching means 15 switches the wiping mode, the detection rate calculating means 13 sets the rain detection rate to 0%. Thereby, regarding the calculation of the detection rate, the number of wiper wiping operations Cw serving as the denominator can be prevented from increasing, so that the detection rate can be appropriately calculated.
(4) In this embodiment, the rain sensor 1 includes a prohibiting unit 18 that prohibits switching of the wiping mode for a predetermined time after the wiping mode is switched. Thus, the wiping mode is maintained until the detection rate is stabilized at a value corresponding to the rainy state.

(Comparative example)
Next, the wiper automatic control process of the rain sensor according to the comparative example will be described based on the flowchart of FIG.
In the comparative example, in S30, the amount A of raindrops attached to the raindrop detection area during the wiper wiping operation is detected.
In S40, it is determined whether or not the raindrop amount A is greater than or equal to the mode-up threshold. When the raindrop amount A is smaller than the mode-up threshold (S40, NO), the process proceeds to S110.
In S110, it is determined whether or not the raindrop amount A is equal to or less than the mode-down threshold. When the raindrop amount A is larger than the mode-down threshold (S110, NO), the process proceeds to S30, and S40 and S110 are repeated. During this time, the wiping mode is maintained.

In S40, when the raindrop amount A is greater than or equal to the mode-up threshold (S40, YES), the mode-up counter is incremented by 1, and the process proceeds to S90.
When the number of mode up counters is less than 3 set in advance in S90 (S90, NO), the process proceeds to S30. When the number of mode up counters becomes 3 in S90 (S9, YES), the process proceeds to S100 and the mode is up.

On the other hand, if it is determined in S110 that the raindrop amount A is equal to or less than the mode-down threshold (S110, YES), the mode-down counter is incremented by 1, and the process proceeds to S160.
In S160, when the number of mode down counters is less than 3 set in advance (S160, NO), the process proceeds to S30. When the number of mode down counters becomes 3 in S160 (S160, YES), the process proceeds to S170 and the mode is down.

In the comparative example, the number of determinations used for switching the wiping mode is stored in advance in the memory of the rain sensor. The mode is increased when the number of determinations continues for a raindrop amount equal to or greater than the mode-up threshold, and the mode is decreased when the number of determinations continues for a raindrop amount equal to or less than the mode-down threshold. For this reason, the wiping mode cannot be switched while the number of times of determination elapses. Therefore, there is a concern that the response of the wiping mode deteriorates in the comparative example.
In addition, since there is a possibility that raindrops do not adhere to the raindrop detection area of the front windshield when there is little rain, the stability of the wiping mode during light rain may deteriorate if the number of determinations set in advance is small.

(Other embodiments)
In another embodiment, the rain detection rate B may be calculated from the number of times Cr that the raindrop detecting unit has detected a raindrop for a certain time with respect to the number of wiper wiping operations Cw for a certain time. Thereby, it is possible to prevent the number of wiper wiping operations Cw as a denominator from increasing, and to appropriately calculate the detection rate.
In another embodiment, the wiping mode switching unit stops the wiper wiping operation when the rain detection rate is large and the raindrop amount is equal to or less than the mode-down threshold for the number of determinations set by the determination number setting unit. You may do it. Thereby, the responsiveness of the wiping mode when the vehicle enters the tunnel can be enhanced.
The present invention is not limited to the above embodiment, and can be implemented in various forms without departing from the spirit of the invention.

1 ... Rain sensor (wiper control device)
DESCRIPTION OF SYMBOLS 4 ... Raindrop detection area 5 ... Raindrop sensor 11 ... Raindrop amount detection means 12 ... Raindrop detection means 13 ... Detection rate calculation means 14 ... Determination frequency setting means 15 ... Wiping mode Switching means

Claims (5)

A raindrop sensor (5) for outputting a signal corresponding to the raindrop attached to the raindrop detection region (4);
Based on the output signal of the raindrop sensor, the amount of raindrops adhering to the raindrop detection area is detected from a predetermined time when the wiper performs one reciprocating operation to a predetermined time when the wiper performs one reciprocating operation next time. Raindrop amount detecting means (11) for
Based on the output signal of the raindrop sensor, whether raindrops have adhered to the raindrop detection area between a predetermined time when the wiper performs one reciprocating operation and a predetermined time when the wiper performs one reciprocating operation next time . Raindrop detection means (12) for detecting whether or not,
A detection rate calculation means (13) for calculating, as a rain detection rate, the number of times that the raindrop detection means has detected a raindrop with respect to the number of wiper wiping operations from the time of starting control or switching the wiping mode ;
A determination number setting means (14) for setting a smaller number of determinations to be used for the wiping mode switching determination as the rain detection rate is larger, and setting a larger number of determination times as the rain detection rate is smaller;
When the raindrop amount is equal to or greater than the mode-up threshold, the wiping mode with a short time interval is switched to the wiping mode with the determination count setting means, and the determination count setting means sets the determination count continuously. A wiper control device comprising: a wiping mode switching means (15) for switching to a wiping mode having a long time interval when the amount of raindrops is equal to or less than a mode-down threshold.   2. The wiper control device according to claim 1, wherein when the wiping mode switching means switches the wiping mode, the detection rate calculating means sets the rain detection rate to 0%.   The wiper according to claim 1 or 2, further comprising prohibiting means (18) for prohibiting switching of the wiping mode by the wiping mode switching means for a predetermined time after the wiping mode switching means switches the wiping mode. Control device.   The detection rate calculating means calculates, as a rain detection rate, the number of times that the raindrop detecting means has detected a raindrop between the start of control and the present time, with respect to the number of wiper wiping operations from the start of control to the present. The wiper control device according to any one of claims 1 to 3.   The said detection rate calculating means calculates the frequency | count that the said raindrop detection means detected the raindrop in the fixed time with respect to the frequency | count of the wiper wiping operation | movement of a fixed time as a rain detection rate. The wiper control device according to claim 1.

Images