JP6086088B2 - Wiper control device - Google Patents

Description

  The present invention relates to a wiper control device, and more particularly to a wiper control device that automatically controls a wiper.

  2. Description of the Related Art Conventionally, a technique for automatically controlling the operation timing of a wiper, the wiping speed, and the like by detecting the amount of raindrops attached to the outer surface of a windshield is known. For example, Patent Document 1 discloses a technique for automatically controlling a wiper. When there is a possibility that the host vehicle may collide with an obstacle, the wiper is automatically operated in the direction in which the obstacle exists, and the driver Alarm is disclosed. In addition, Patent Document 2 discloses a technique related to the present invention.

JP 2009-107494 A JP 2008-155708 A

  By the way, when there is an obstacle ahead in rainy weather, in order to suppress the deterioration of the visibility of the front obstacle due to raindrops attached to the windshield, It is considered desirable to wipe off raindrops early. On the other hand, when there is no obstacle ahead, it is considered that the wiper does not have to be operated quickly. Depending on the driver, it may be annoying to automatically operate the wiper, so it is not always best to operate the wiper quickly in the rain. Note that neither Patent Documents 1 and 2 disclose anything about controlling the operation timing of the wiper according to the presence or absence of a front obstacle.

  The present invention has been made to solve the above-described problems of the prior art, and provides a wiper control device capable of operating a wiper at an appropriate timing according to the presence or absence of a front obstacle. Objective.

In order to achieve the above object, the present invention provides a wiper control device for automatically controlling a wiper of a vehicle, comprising a raindrop detection means for detecting a raindrop state of raindrops attached to an outer surface of a windshield, and a front side of the host vehicle. Obstacle detection means for detecting the obstacle of the vehicle, and wiper control means for automatically operating the wiper when the value of the parameter indicating the raindrop state detected by the raindrop detection means exceeds the wiper operation determination value. The wiper control means has a smaller wiper operation determination value when an obstacle is detected by the obstacle detection means than when no obstacle is detected by the obstacle detection means. And
In the present invention configured as described above, the wiper control means uses the wiper operation determination value used for the parameter indicating the raindrop state in order to determine whether or not to operate the wiper when the front obstacle exists. When there is a front obstacle in the rain, the wiper is quickly activated to wipe out the raindrop and the front obstacle is visually recognized by the raindrop attached to the windshield. Sexual deterioration can be appropriately suppressed. That is, the visibility of the front obstacle can be secured early.
Further, in the present invention, only when there is a forward obstacle, the wiper operation determination value is reduced so as to advance the operation timing of the wiper, that is, the operation timing of the wiper is not wasted earlier. The troublesomeness given to the driver when the wiper is automatically operated can be appropriately suppressed.

In the present invention, preferably, it further has an effective visual field estimating means for estimating an effective visual field of the driver through the windshield based on the raindrop state detected by the raindrop detecting means, and the wiper control means is configured to detect an obstacle. When the obstacle detected by the means is located outside the effective visual field, the wiper operation determination value is made smaller than when the obstacle detected by the obstacle detection means is located within the effective visual field.
In the present invention configured as described above, when the front obstacle is located outside the effective visual field, the wiper operation determination value is made smaller than when the front obstacle is located within the effective visual field. When an object is located outside the effective field of view, the wiper can be actuated quickly to remove raindrops, thereby ensuring early visibility of the front obstacle located outside the effective field of view.

In the present invention, the wiper control means preferably makes the wiper operation determination value smaller when the obstacle detection means detects the obstacle than when the obstacle detection means detects no obstacle. At the same time, control for increasing the wiping speed when the wiper is operated and / or control for shortening the intermittent time are performed.
In the present invention configured as described above, when a forward obstacle is detected and the wiper operation determination value is decreased, the control for increasing the wiping speed when the wiper is operated and / or the intermittent time is shortened. Since the control is performed, raindrops attached to the windshield can be effectively wiped off, and the visibility of the front obstacle can be reliably ensured.

In the present invention, preferably, when an obstacle is detected by the obstacle detection means, an alarm relating to the obstacle is displayed on the windshield and in the operating range of the wiper by the head-up display.
In the present invention configured as described above, the head-up display displays an alarm regarding the front obstacle on the windshield and in the operating range of the wiper when the front obstacle exists. Moreover, since the wiper control means quickly operates the wiper to wipe away raindrops, it is possible to appropriately suppress the deterioration of the visibility of the alarm display due to the raindrops adhering to the windshield. Therefore, in the present invention, it is possible to ensure the visibility of the alarm display by the head-up display while ensuring the forward view through the windshield by the operation of the wiper, so that the presence of the front obstacle is appropriate for the driver. Can be noticed.

  According to the wiper control device of the present invention, the wiper can be operated at an appropriate timing according to the presence or absence of a front obstacle.

1 is a perspective view of a vehicle according to an embodiment of the present invention. 1 is a block diagram of a vehicle communication system according to an embodiment of the present invention. 1 is a block diagram illustrating an overall configuration of a wiper control device according to an embodiment of the present invention. It is explanatory drawing which shows the display by the head-up display by embodiment of this invention. It is explanatory drawing which shows an example of the raindrop detection principle of a windshield. It is a graph which shows an example of correlation with a raindrop adhesion rate and the output of a raindrop detection means. It is explanatory drawing of experiment which verifies the reaction time by a raindrop state. It is a graph which shows the relationship between the display position (horizontal angle) of a target stimulus, and reaction time for every display speed of disturbing stimulus. It is the map with which the effective visual field size was matched with the raindrop adhesion speed. It is a flowchart which shows the wiper action | operation control process by embodiment of this invention. It is a map in which a wiper operation determination value is associated with an effective visual field size.

  Hereinafter, a wiper control device according to an embodiment of the present invention will be described with reference to the accompanying drawings.

First, the configuration of a wiper control device according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view of a vehicle according to an embodiment of the present invention, FIG. 2 is a block diagram of a vehicle communication system according to an embodiment of the present invention, and FIG. 3 is a wiper control device according to an embodiment of the present invention. It is a block diagram which shows the whole structure.
In the description using FIGS. 1 to 3, the accompanying FIGS. 4 to 6 are also referred to. FIG. 4 is an explanatory view showing the display by the head-up display, FIG. 5 is an explanatory view showing the principle of detecting raindrops on the windshield, and FIG. 6 is a correlation between the raindrop adhesion rate and the output of the raindrop detecting means. It is a graph which shows.

  As shown in FIGS. 1 and 2, the host vehicle V is a raindrop detection unit that can detect the raindrop state of raindrops attached to the outer surface of the windshield 1, and a rain as a wiper control unit that automatically operates the wiper 11. The wiper control device 3 according to the embodiment of the present invention includes a sensor 2, a millimeter wave radar 13 as an obstacle detection unit capable of detecting an obstacle around the host vehicle V, and the like. And a millimeter wave radar 13 or the like.

First, a basic communication system of the host vehicle V will be described.
As shown in FIG. 2, the automobile V includes a body control module (hereinafter referred to as “BCM”) 4, an engine control module (hereinafter referred to as “ECM”) 5, and a head. An up display (Head-Up Display: hereinafter referred to as “HUD”) 8 is provided, and these control mechanisms 4, 5, 8 are connected to each other by a CAN (Controller Area Network) 10 so as to be able to transmit and receive each other.

As shown in FIGS. 2 and 3, the BCM 4 is configured to be capable of comprehensive control of a plurality of devices such as the wiper 11 and the rain sensor 2, and includes a microcomputer (hereinafter referred to as “microcomputer”) 12. The wiper 11 is configured to be able to execute each mode control such as an auto mode control when a driver manually operates a wiper switch (not shown).
The microcomputer 12 writes a CPU that performs control processing and arithmetic processing, a read-only memory (ROM) for storing various data such as various programs and control coefficients, and various data output from the ECM 5 and a plurality of sensors. It includes a possible memory (RAM), a power supply circuit, etc. (both not shown), converts a control signal output from the microcomputer 30 to be described later, and transmits it to the wiper 11.

  The ECM 5 is configured to be able to control an engine ignition mechanism, a fuel injection device, an intake / exhaust system, a valve mechanism, start control, and the like based on a plurality of sensor outputs (all not shown). The ECM 5 includes an ECU (Electronic Control Unit) 40 and supports driving for the millimeter wave radar 13 that can receive reflected radio waves by irradiating millimeter waves (for example, 76 GHz) forward in the traveling direction, and the driver. For this purpose, it is electrically connected to a HUD 8 or the like that displays information on the windshield 1.

  As shown in FIG. 1, the millimeter wave radar 13 is a radar unit that can detect an obstacle (for example, another vehicle or a pedestrian) in front of the host vehicle V, such as an emblem of a front bumper of the host vehicle V. At the rear side, it is attached to the front. The millimeter wave radar 13 includes a light receiver (not shown) capable of receiving reflected light from an obstacle, and is configured to be able to scan at predetermined angles (for example, 0.1 °) in the horizontal direction. Instead of the millimeter wave radar 13, various radars having the above-described functions can be employed.

  As shown in FIG. 4, when a front obstacle is detected by the millimeter wave radar 13, the HUD 8 displays an alarm (see reference numeral 61) regarding the front obstacle on the windshield 1. FIG. 4 illustrates a case where an alarm “pedestrian attention” is displayed by the HUD 8. Further, the HUD 8 displays such an alarm in the operating range 62 of the wiper 11 on the windshield 1 (that is, a range in which raindrops attached to the windshield 1 can be wiped off by the wiper 11).

As shown in FIG. 2, the CAN 10 connects the control mechanisms 4, 5, and 8 via the CAN bus 10 a so that multiplex communication is possible, and performs bus access control by a multi-master system that transmits data in units of frames (not shown). ing. In each frame, an arbitration ID and a vehicle ID corresponding to the model of the host vehicle V are set in advance for each frame. The smaller the arbitration ID, the higher the priority for flowing the frame to the CAN bus 10a. .
Communication signals output from the control mechanisms 4, 5, 8 and various sensors are stored in the data field of the frame and transmitted to each transmission destination via the CAN bus 10 a.

Next, the rain sensor 2 will be described.
As shown in FIGS. 1 to 3, the rain sensor 2 is detachably mounted at a position facing the raindrop detection region set in front of the rearview mirror and at the upper end of the outer surface of the windshield 1. The rain sensor 2 includes a plurality of (for example, four) raindrop detection units 20 and a microcomputer (hereinafter referred to as “microcomputer”) 30.

  As shown in FIGS. 3 and 5, the raindrop detection unit 20 includes a light projecting unit 22, a light projecting unit control unit 23 that controls the light projecting unit 22, a parallel light lens 24, a condenser lens 25, A light receiving unit 26 and a light receiving unit control unit 27 for controlling the light receiving unit 26 are provided. Since the four sets of raindrop detection units 20 have the same configuration, the one set of raindrop detection units 20 will be mainly described.

The light projecting unit 22 is formed by a light emitting element (for example, LED), and is configured to be able to irradiate infrared rays α to a portion corresponding to the raindrop detection region on the inner surface of the windshield 1.
The light projecting unit control unit 23 is configured to be able to control the operation timing of the light projecting unit 22, the irradiation amount (intensity) of the infrared ray α, and the like based on a control signal from the microcomputer 30.
As shown in FIG. 5, the parallel light lens 24 is formed such that the surface on the light projecting unit 22 side is convex and the surface on the windshield 1 side is formed in a planar shape, and the traveling direction of the infrared rays α irradiated from the light projecting unit 22. Is changed from the diffusion direction to the parallel direction. The parallel light lens 24 has an inclination angle or the like so that the infrared ray α is totally reflected from the outer boundary surface of the windshield 1 when no raindrop W is attached to the outer face of the windshield 1.

  The condensing lens 25 is formed such that the surface on the windshield 1 side is convex and the surface on the light receiving unit 26 side is flat. Since the infrared rays α reflected from the outer boundary surface of the windshield 1 or the infrared rays α2 reflected from the outer boundary surface of the raindrops W travel in parallel, the condensing lens 25 receives these parallel infrared rays α or α2. The traveling direction of the infrared rays α or α2 is changed from the parallel direction to the converging direction so as to concentrate on the light receiving unit 26. The light receiving unit 26 includes a light receiving element (for example, a photodiode), and is configured to detect infrared rays α and α2 reflected from the outer boundary surface of the windshield 1 and the outer boundary surface of the raindrop W. The light receiving unit control unit 27 is configured to be able to control the light receiving sensitivity and the focal point of the light receiving unit 26 based on the control signal from the microcomputer 30, and the infrared α or α2 detection signal detected by the light receiving unit 26 to the microcomputer 30. Output.

Here, the raindrop detection principle of the raindrop detector 20 will be briefly described.
As shown in FIG. 5, the raindrop W is formed in a flat shape due to the influence of the hydrophilic characteristics of the windshield 1 and gravity.
The parallel light lens 24 has an inclination angle or the like so that the infrared ray α irradiated from the light projecting unit 22 is totally reflected from the planar outer boundary surface between the windshield 1 and the external space. In a portion where no raindrop W is attached to the outer side surface, the infrared rays α irradiated from the light projecting unit 22 are totally reflected from the outer boundary surface of the windshield 1 without passing through the windshield 1. Further, in the portion where the raindrops W are dropped and the flat raindrops W are attached to the outer surface of the windshield 1, some of the infrared rays α1 irradiated from the light projecting unit 22 are part of the infrared rays α1. The remaining infrared rays α2 (α−α1) are reflected from the outer boundary surface between the raindrops W and the external space. Thereby, the raindrop detection unit 20 detects the amount of reflected light of the infrared ray α or α2 that is the reflected light from the outer surface of the windshield 1 or the raindrop W.

Next, the microcomputer 30 will be described.
The microcomputer 30 detects the amount of raindrops attached to the outer surface of the windshield 1 based on the amount of reflected light of infrared rays α or α2 detected by the raindrop detector 20.
As shown in FIG. 3, the microcomputer 30 includes a raindrop detection processing unit 31, a raindrop state detection unit 32, an auto wiper determination unit 33, an effective visual field estimation unit 34, and a wiper control unit 35. It is configured.

In the raindrop detection processing unit 31, an average output is calculated for the output of each reflected light received by the four sets of light receiving units 26, and a value obtained by converting the average output to a negative value and adjusting the minimum value to zero is obtained. It is set as output x.
As shown in FIG. 6, since the adhesion rate of the raindrops W to the windshield 1 is substantially proportional to the output x, the raindrop state detection unit 32 uses the raindrop detection processing unit 31 based on this correlation. The output x set in step 1 is converted into an adhesion rate X (%).
Here, the adhesion rate X of the raindrop detection unit 20 converted from the output x is set to 0% when the raindrop W adhered to the raindrop detection region on the windshield 1 is not present, and the raindrop detection on the windshield 1 is detected. When raindrops W adhere to the entire area, the deposition rate is set to 100%. In FIG. 6, the output x is not output at a predetermined raindrop adhesion rate (for example, 1.0%) or less due to the detection accuracy of the raindrop detector 20.

  In the raindrop state detection unit 32, the amount of raindrops adhering to the windshield 1 based on the decreasing tendency (decrease width) of the average output of each reflected light received by the four sets of light receiving units 26 of the raindrop detection unit 20, and a predetermined time A change amount dX of the adhesion rate X in (for example, 0.1 to 1 sec) is calculated. The raindrop amount measured based on the output value of the raindrop detection unit 20 corresponds to the raindrop amount detected by the rain sensor 2, and the change dX obtained by time-differentiating the adhesion rate X corresponds to the deposition rate of raindrops.

  The auto wiper determination unit 33 determines whether or not the user has operated the wiper switch to select the auto mode control.

  The effective visual field estimation unit 34 estimates the effective visual field of the driver through the windshield 1 based on, for example, the raindrop adhesion speed dX detected by the raindrop state detection unit 32. Details of this effective visual field will be described later.

  The wiper control unit 35 controls the wiper 11 based on the basic function of controlling the wiper 11 according to the mode control selected by the driver and the raindrop state detected by the raindrop state detection unit 32 when the auto mode control is selected. And an automatic control function for automatically controlling. For example, when the automatic mode control is selected, the wiper control unit 35 has an adhesion rate X, which is one of the parameters indicating the raindrop state detected by the raindrop state detection unit 32, exceeding a predetermined determination value (wiper operation determination value). The wiper 11 is automatically operated, that is, the operation of the wiper 11 is started. Further, the wiper control unit 35 performs control to change the wiping speed and / or the intermittent time of the wiper 11 based on the raindrop state detected by the raindrop state detection unit 32 when the auto mode control is selected. In the present embodiment, details of the control performed by the wiper control unit 35 will be described later.

  Next, the above-described effective visual field will be specifically described with reference to FIGS.

  FIG. 7 is an explanatory diagram of an experiment for verifying the reaction time depending on the raindrop state. As shown in FIG. 7, the subject's gaze point 51 (for example, a number) corresponding to the traveling direction of the vehicle is displayed on the display 50, and the target stimulus 52 (for example, the number) corresponding to the front obstacle is irregularly displayed. The circular disturbing stimulus 53 corresponding to the raindrop is displayed under a predetermined condition. When the subject gazes at the gazing point 51 and recognizes the target stimulus 52, the subject pushes the push button 54, and measures the reaction time from the display of the target stimulus 52 until the push button 54 is operated. In this verification experiment, in order to verify the influence of raindrops on the reaction time in the central visual field and the peripheral visual field, the target stimulus 52 is displayed at various positions on the display 50 and the display speed (0, 6) of the disturbing stimulus 53 is displayed. .7, 20.0).

  FIG. 8 is a graph showing the relationship between the display position of the target stimulus 52 and the reaction time for each display speed of the disturbing stimulus 53. Specifically, FIG. 8 shows the response of the target stimulus 52 to the horizontal angle [deg] corresponding to the display position of the target stimulus 52 for each display speed (0, 6.7, 20.0) of the disturbing stimulus 53. Time [sec] is shown. In the horizontal axis of this figure, the central visual field is shown in the center, and the left and right peripheral visual fields are shown on both sides thereof. As shown in FIG. 8, in the central visual field, there is no difference in the reaction time depending on the display speed of the disturbing stimulus 53, but in the peripheral visual field, it can be seen that the response time becomes longer as the display speed of the disturbing stimulus 53 increases. .

From these results, it was found that in rainy weather, the visual recognition time in the peripheral visual field of the driver through the windshield 1 is longer than that in the central visual field. This is equivalent to the case where there is a stimulus with characteristics different from the surrounding stimulus in the human visual field, and the stimulus is conspicuous (pops out) and attracts the attention of the human, so there is no such stimulus. This is because the range of the field of view in which the viewing time is secured is narrowed. That is, in the rainy weather, the driver's attention is attracted to the raindrops attached to the windshield 1, so that the visual field range in which the viewing time equivalent to that when no raindrops are attached to the windshield 1 is secured is reduced. .
Here, for example, the range of the visual field in which the visual recognition time for the object in the visual field is a predetermined time or less is defined as the effective visual field. For this predetermined time, for example, a time longer than the visual recognition time in the central visual field is used. If the effective visual field is defined in this way, the effective visual field is reduced when it is raining, compared to when it is not raining (that is, when raindrops are not attached to the windshield 1).

  The effective visual field estimation unit 34 in the microcomputer 30 of the rain sensor 2 described above estimates such an effective visual field based on the raindrop state of raindrops attached to the outer surface of the windshield 1. Specifically, the effective visual field estimation unit 34 refers to a map as illustrated in FIG. 9 and acquires the size of the effective visual field. The map shown in FIG. 9 has an effective visual field size [mm] associated with the raindrop adhesion speed dX, and is created in advance based on the verification experiment described above. According to this map, the smaller the raindrop adhesion speed dX, the smaller the effective visual field size is determined. The effective visual field estimation unit 34 refers to such a map, and acquires an effective visual field size corresponding to the raindrop adhesion speed dX detected by the raindrop state detection unit 32.

Next, in this embodiment, an outline of control that automatically operates the wiper 11 performed by the wiper control unit 35 in the microcomputer 30 of the rain sensor 2 will be described.
In the present embodiment, the wiper control unit 35 uses a wiper operation determination value (for example, a determination value applied to the adhesion rate X) for determining whether to automatically operate the wiper 11 based on the raindrop state. , Change according to the presence of obstacles ahead. Specifically, the wiper control unit 35 makes the operation timing of the wiper 11 earlier by reducing the wiper operation determination value when the front obstacle is present than when the front obstacle is not present. To do. This is because, when there is an obstacle ahead in the rain, the wiper 11 is actuated promptly in order to prevent the visibility of the front obstacle from being deteriorated by raindrops attached to the windshield 1. This is because it is desirable to quickly secure the forward visibility through the windshield 1 by wiping raindrops.

  Further, in the present embodiment, the wiper control unit 35 changes the wiper operation determination value according to the above-described effective visual field. Specifically, when the front obstacle is located outside the effective field of view, the wiper control unit 35 reduces the wiper operation determination value when the front obstacle is located within the effective field of view. 11 is advanced. This is because, when the front obstacle is located outside the effective field of view, the driver's visual recognition of the front obstacle is delayed. This is because it is necessary to ensure the visibility of obstacles ahead.

As described above, in the present embodiment, the wiper control unit 35 changes the wiper operation determination value according to the presence or absence of the front obstacle, and when the front obstacle exists, the front obstacle is out of the effective visual field. The wiper operation determination value is changed depending on whether or not it is positioned in the position. That is, the wiper control unit 35 includes (1) a case where a front obstacle exists and the front obstacle is located outside the effective visual field, and (2) a front obstacle exists and the front obstacle is within the effective visual field. And (3) different wiper operation determination values are used for the case where there is no forward obstacle. Hereinafter, the wiper operation determination value used in the case of (1) is referred to as “first wiper operation determination value”, and the wiper operation determination value used in the case of (2) is referred to as “second wiper operation determination value”. The wiper operation determination value used in the case of 3) is referred to as a “third wiper operation determination value”. The relationship between these wiper operation determination values is “first wiper operation determination value <second wiper operation determination value <third wiper operation determination value”.
For example, the third wiper operation determination value is generally set in consideration of the timing at which the driver manually operates the wiper 11 according to the raindrop state, and the first wiper operation determination value is such a third wiper operation value. A value obtained by subtracting the predetermined value a1 from the operation determination value is set, and the second wiper operation determination value is set to a value obtained by subtracting the predetermined value a2 (a2 <a1) from the third wiper operation determination value. For example, as the first to third wiper operation determination values, a value [%] corresponding to the adhesion rate X is used to determine the adhesion rate X.

  Next, with reference to FIG. 10, the control process which the wiper control part 35 performs in order to operate the wiper 11 automatically in embodiment of this invention is demonstrated. FIG. 10 is a flowchart showing a wiper operation control process according to the embodiment of the present invention. This wiper operation control process is executed only when the auto mode control is selected.

  First, in step S <b> 1, the wiper control unit 35 determines whether a raindrop is detected by the raindrop detection unit 20. When no raindrop is detected as a result of the determination in step S1, the wiper control unit 35 repeats the determination in step S1.

  If raindrops are detected as a result of the determination in step S <b> 1, the process proceeds to step S <b> 2 and the wiper control unit 35 determines whether or not a front obstacle has been detected by the millimeter wave radar 13. Specifically, the millimeter wave radar 13 detects an obstacle in front of the host vehicle V by detecting the distance of the obstacle ahead of the host vehicle V and a relative speed obtained by time-differentiating the distance. It is determined whether or not.

  If a front obstacle is detected as a result of the determination in step S2, the process proceeds to step S3, and the effective visual field estimation unit 34 estimates an effective visual field within the driver's visual field through the windshield 1. Specifically, the effective visual field estimation unit 34 refers to a map as illustrated in FIG. 9 and acquires the effective visual field size corresponding to the raindrop adhesion speed dX detected by the raindrop state detection unit 32.

  Next, in step S4, the wiper control unit 35 determines whether or not the front obstacle is located outside the effective visual field. Specifically, the wiper control unit 35 includes the position of the front obstacle specified from the detection signal from the millimeter wave radar 13 in the range of the visual field corresponding to the effective visual field size acquired by the effective visual field estimation unit 34. It is determined whether or not.

  As a result of the determination in step S4, when the front obstacle is located outside the effective visual field, the process proceeds to step S5, and the wiper control unit 35 sets the wiper operation determination value among the above-described first to third wiper operation determination values. The smallest first wiper operation determination value is set.

  On the other hand, if the result of the determination in step S4 is that the front obstacle is located within the effective visual field, the process proceeds to step S6, and the wiper control unit 35 uses the first to third wiper operations described above as the wiper operation determination values. The second wiper operation determination value that is the second smallest among the determination values is set.

  On the other hand, if the front obstacle is not detected as a result of the determination in step S2, the process proceeds to step S7, and the wiper control unit 35 sets the wiper operation determination value to the above-described first to third wiper operation determination values. Is set to the largest third wiper operation determination value.

  After steps S5, S6, and S7, the process proceeds to step S8, and the wiper control unit 35 determines whether or not it is time to operate the wiper 11 based on the set wiper operation determination value. For example, the wiper control unit 35 determines whether or not the adhesion rate X indicating the raindrop state detected by the raindrop state detection unit 32 exceeds the wiper operation determination value. As a result of the determination in step S8, when it is not time to operate the wiper 11, the wiper control unit 35 repeats the determination in step S8.

  On the other hand, if it is determined in step S8 that it is time to operate the wiper 11, the process proceeds to step S9, and the wiper control unit 35 automatically operates the wiper 11, that is, starts the operation of the wiper 11. .

  Next, functions and effects of the wiper control device according to the embodiment of the present invention will be described.

  In the present embodiment, the wiper control unit 35 uses the wiper operation determination value for determining whether or not to operate the wiper 11 based on the raindrop state when the forward obstacle exists and the forward obstacle does not exist. Therefore, when there is a front obstacle when it rains, the wiper 11 is quickly operated to wipe off the raindrop, and the deterioration of the visibility of the front obstacle due to the raindrop adhering to the windshield 1 is appropriately prevented. Can be suppressed. That is, the visibility of the front obstacle can be secured early.

  In the present embodiment, the wiper control unit 35 makes the wiper operation determination value smaller when the front obstacle is located outside the effective field of view than when the front obstacle is located within the effective field of view. When the front obstacle is located outside the effective visual field, the wiper 11 can be actuated quickly to wipe away raindrops, thereby ensuring early visibility of the front obstacle located outside the effective visual field.

  Thus, in the present embodiment, the wiper operation determination value is reduced so as to advance the operation timing of the wiper 11 only when the above-described conditions are satisfied, that is, the operation timing of the wiper 11 is wasted earlier. Since nothing is done, the troublesomeness given to the driver when the wiper 11 is automatically operated can be appropriately suppressed.

  Furthermore, in this embodiment, when a front obstacle exists, the HUD 8 displays an alarm regarding the front obstacle on the windshield 1 and in the operating range 62 of the wiper 11 (see FIG. 4). In this case, since the wiper control unit 35 quickly operates the wiper 11 to wipe away raindrops, it is possible to appropriately suppress the deterioration of the visibility of the alarm display due to the raindrops adhering to the windshield 1. Therefore, since the visibility of the alarm display by the HUD 8 can be ensured while the forward view through the windshield 1 is secured by the operation of the wiper 11, the presence of the front obstacle can be appropriately noticed to the driver. it can.

  Below, the further modification of embodiment of this invention is demonstrated.

In the above-described embodiment, the wiper operation determination value is changed depending on whether or not the front obstacle is located outside the effective visual field. However, the wiper operation determination value may be further changed according to the effective visual field size. In that case, in one example, the wiper operation determination value is changed depending on whether or not the front obstacle is located outside the effective visual field, and the wiper operation determination value is changed according to the effective visual field size. In this example, the wiper operation determination value is changed according to the effective visual field size, and the wiper operation determination value after the change is further reduced when the front obstacle is located outside the effective visual field. In another example, instead of changing the wiper operation determination value depending on whether or not the front obstacle is located outside the effective visual field, the wiper operation determination value is changed according to the effective visual field size. In this example, regardless of whether or not the front obstacle is located outside the effective visual field, when the front obstacle is present, the wiper operation determination value is changed according to the effective visual field size.
Specifically, the wiper operation determination value may be changed according to the effective visual field size using a map as shown in FIG. FIG. 11 shows a map in which the wiper operation determination value to be set is associated with the effective visual field size [mm]. According to this map, the wiper operation having a smaller value as the effective visual field size becomes smaller. A judgment value is determined. The wiper control unit 35 refers to such a map and sets a wiper operation determination value corresponding to the effective visual field size estimated by the effective visual field estimation unit 34.

  In the embodiment described above, the wiper operation determination value is changed according to various conditions. However, when the wiper operation determination value is changed, the wiping speed and / or the intermittent time when the wiper 11 is operated is changed. May be. Specifically, the wiper control unit 35 determines the wiping speed when the wiper 11 is operated when reducing the wiper operation determination value according to the above-described conditions (see the conditions (1) and (2)). Control for speeding up and / or control for shortening the intermittent time when the wiper 11 is operated may be performed. Thereby, the raindrop adhering to the windshield 1 can be wiped off effectively, and the visibility of a front obstacle can be ensured appropriately.

In the embodiment described above, the raindrop state is detected using the raindrop detection unit 20 (see FIGS. 3 and 5), but instead of the raindrop detection unit 20 or in addition to the raindrop detection unit 20, the windshield 1 The raindrop state may be detected by using an image pickup means (for example, a CCD camera) for photographing the raindrop detection area.
In the above-described embodiment, the adhesion rate X is exemplified as a parameter indicating the raindrop state. However, in addition to the adhesion rate X, the deposition rate of raindrops (the number of raindrops deposited per unit time within a predetermined range of the windshield 1) Number), raindrop diameter (size of raindrops attached to the windshield 1), and contrast between raindrop brightness and external brightness (brightness difference between the raindrop-attached portion and the raindrop-free portion on the windshield 1) May be used as a parameter indicating the raindrop state. Such a deposition rate of raindrops, a raindrop diameter, and a contrast between raindrop brightness and external brightness can be detected using the above-described imaging means.
Furthermore, the wiper operation determination value may be changed according to the deposition speed of raindrops, the raindrop diameter, and the contrast between the raindrop brightness and the external brightness. In such a case, the faster the raindrop adhesion speed, the smaller the wiper operation determination value, the larger the raindrop diameter, the smaller the wiper operation determination value, or the greater the contrast between raindrop brightness and external brightness, the more wiper operation determination. You can reduce the value. In addition, the wiper operation determination value may be changed depending on the vehicle speed, time zone (day / night), or the like. The wiper operation determination value thus changed is further changed according to the presence or absence of the front obstacle and whether or not the front obstacle is located outside the effective visual field, as shown in the above-described embodiment. Just do it.
Although the wiper operation determination value can be changed using the various parameters as described above, the wiper operation determination value may be set to a value [%] in which the adhesion rate X can be determined.

  In the above-described embodiment, the front obstacle is used as a condition for changing the wiper operation determination value. However, the front obstacle may be limited to the one that requires a warning to the driver. That is, even if there is a front obstacle, if it does not require a warning to the driver (for example, an obstacle that is not likely to contact the host vehicle V), the wiper operation determination value is changed. It does not have to be. In that case, the wiper operation judgment value is changed according to the presence or absence of a front obstacle that requires a warning to the driver, and the wiper is activated depending on whether or not the front obstacle that needs a warning to the driver is located outside the effective field of view. What is necessary is just to change a judgment value.

In the embodiment described above, the wiper control unit 35 in the microcomputer 30 of the rain sensor 2 performs control to automatically operate the wiper 11. However, instead of the wiper control unit 35, the ECU 40 in the ECM 5 or the BCM 5 The microcomputer 12 may perform control for automatically operating the wiper 11. In that case, the wiper control means in the present invention is provided not in the rain sensor 2 but in the ECU 40 in the ECM 5 or the microcomputer 12 in the BCM 5.
In the embodiment described above, the effective visual field estimation unit 34 in the microcomputer 30 of the rain sensor 2 estimates the effective visual field, but instead of the effective visual field estimation unit 34, the ECU 40 in the ECM 5 or the BCM 5 The microcomputer 12 may estimate the effective visual field. In that case, the effective visual field estimation means in the present invention is provided not in the rain sensor 2 but in the ECU 40 in the ECM 5 or the microcomputer 12 in the BCM 5.

1 windshield 2 rain sensor 3 wiper control device 8 head-up display (HUD)
13 Millimeter wave radar 20 Raindrop detection unit 30 Microcomputer 32 Raindrop state detection unit 34 Effective visual field estimation unit 35 Wiper control unit

Claims (4)

A wiper control device for automatically controlling a wiper of a vehicle,
Raindrop detection means for detecting the raindrop state of raindrops adhering to the outer surface of the windshield;
Obstacle detection means for detecting an obstacle ahead of the host vehicle;
Wiper control means for automatically operating the wiper when the value of the parameter indicating the raindrop state detected by the raindrop detection means exceeds a wiper operation determination value;
The wiper control means makes the wiper operation determination value smaller when an obstacle is detected by the obstacle detection means than when no obstacle is detected by the obstacle detection means. A wiper control device. Furthermore, it has effective visual field estimation means for estimating the effective visual field of the driver through the windshield based on the raindrop state detected by the raindrop detection means,
When the obstacle detected by the obstacle detection means is located outside the effective visual field, the wiper control means is more effective than when the obstacle detected by the obstacle detection means is located within the effective visual field. The wiper control device according to claim 1, wherein the wiper operation determination value is reduced.   The wiper control means makes the wiper operation determination value smaller when the obstacle detection means detects an obstacle than when no obstacle is detected by the obstacle detection means, and The wiper control device according to claim 1 or 2, wherein control for increasing a wiping speed when the wiper is operated and / or control for shortening an intermittent time are performed.   4. When an obstacle is detected by the obstacle detection means, an alarm regarding the obstacle is displayed on the windshield and in the operating range of the wiper by a head-up display. The wiper control device according to item 1.

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