JPH10213675A - Sediment detection sensor and wiper controller using this sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sediment detection sensor capable of avoiding erroneous detection due to disturbance light with a simple constitution. SOLUTION: At the both ends of a base of longitudinal plate shape, a light projecting part 4 and a light reception light 5 are projectedly formed. On the opposite side of the light reception part 5 of the light reception part 5, a light shield wall 8 where a specific size light projecting window is placed is provided and the light from the light projecting element 6 diffuses via this light casting window to the light reception part 5 side. On the other hand in the light reception part 5, a light reception element 10 and a light reception unit 35 assembled by a lens 9 for guiding light to this light reception element are contained. This light reception element 10 is set its position and the size of the light reception surface so that the view seeing from the light reception surface through the lens 9 comes within the opening edge of the light casting window of the light projecting part 5 and that noise due to disturbance light does not overlap on the output signal and the view field seen through the lens 9 of the light reception surface is within the opening edge of the light casting window of the light casting part 5 and so the light from the outside of the opening is guided to the other location than the light reception surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precipitation detection sensor for detecting precipitation such as raindrops and snow, and to drive a wiper of a vehicle such as an automobile using an output signal of the precipitation detection sensor. Related to a wiper control device.

[0002]

2. Description of the Related Art In recent years, a device for mounting a precipitation detection sensor at an appropriate position on a vehicle to detect rain, snow, or other precipitation flying toward the vehicle, and automatically driving a wiper according to the detection signal. Is being developed. A representative example of this type of precipitation detection sensor is configured such that a light-emitting unit provided with a light source such as a light-emitting element and a light-receiving unit formed of a light-receiving element are opposed to each other at a predetermined distance. Then, the diffused light emitted from the light emitting unit is received by the light receiving unit, and a change in the output signal of the amount of received light is checked to detect the precipitation passing through the light emitting path. The detection result is input to the wiper control device, and a measurement process such as precipitation is performed. When a precipitation exceeding a predetermined threshold is measured, a control signal for driving the wiper is output. .

However, in the sensor having the above-described structure, there is a possibility that disturbance light from a place other than the light projecting portion is incident on the light receiving portion and the level of the received light amount is higher than usual. Under the influence of such disturbance light, when the light reception amount returns to the normal level, it is erroneously detected that the precipitation has passed, and as a result, the wiper malfunctions. In order to solve such a problem, while emitting modulated light from the light emitting unit,
It has been proposed to provide a filter on the light receiving section that allows only a frequency component corresponding to the modulated light to pass therethrough to prevent malfunction of the wiper due to disturbance light (Japanese Utility Model Publication No. 6-18281).
No.).

[0004]

However, when such a configuration is adopted, an oscillation circuit and a drive circuit for generating modulated light are provided on the light projecting portion side, and only the modulated light component is provided on the light receiving portion side. It is necessary to provide a band-pass filter or the like for allowing the light to pass therethrough, which causes a problem that the device configuration is complicated and the manufacturing cost is increased.

The present invention has been made in view of the above-mentioned problems, and the erroneous detection due to disturbance light can be avoided with a simple configuration by adjusting the size of the field of view expected by the light receiving unit according to the light irradiation area. It is an object of the present invention to provide a precipitation sensor capable of detecting the precipitation.

According to a second aspect of the present invention, a wiper of a vehicle is driven on the basis of a detection output of a precipitation sensor having the above-described configuration to appropriately control a wiper operation without being affected by disturbance light. Make it an issue.

[0007]

According to a first aspect of the present invention, there is provided a precipitation detecting sensor, comprising: a light projecting unit in which projected light is diffused; and a light receiving unit for receiving light from the light projecting unit. Are disposed opposite each other at a predetermined distance to detect the precipitation passing through the optical path of the diffused light based on the output signal of the light receiving unit, and the light projecting unit is located at a position in front of the light source. And a light projecting window for projecting the diffused light to the optical path.
The light receiving unit has a light receiving element and a lens for guiding light to a light receiving surface of the light receiving element. The light receiving element has an opening edge of the light projecting window within a visual field viewed through the lens from the light receiving surface. Include, but do not include outside the periphery of the opening,
The size and position of the light receiving surface are set.

According to a second aspect of the present invention, there is provided a precipitation detecting sensor, a light projecting portion, a reflecting wall surface for receiving and reflecting light from the light projecting portion, and receiving light reflected from the reflecting wall surface. Having a light receiving portion, and detecting the precipitation passing through the reflected light path based on an output signal of the light receiving portion. The light receiving portion has a light receiving element and a light receiving surface of the light receiving element. And a light-receiving element, wherein the light-receiving element includes a peripheral portion of the reflective wall surface in a visual field viewed through the lens from the light-receiving surface, but does not include a portion outside the peripheral portion, so that the light-receiving element has a light-receiving surface. The size and position are set.

In the light receiving section of the precipitation detecting sensor according to the third aspect of the present invention, a slit plate having a slit hole is provided in front of the lens so as to cross the optical axis thereof.

A precipitation sensor according to a fourth aspect of the present invention comprises:
A filter that passes only a signal in a predetermined frequency band based on a width of light guided to the light receiving surface, a representative size of rainfall, and a falling velocity is provided at a stage subsequent to the light receiving unit. Is done.

According to a fifth aspect of the present invention, there is provided a wiper control device having the structure of any one of the first to fourth aspects, a driving means for driving a vehicle wiper, and the And control means for operating the driving means based on the detection result by the detection sensor.

In the wiper control apparatus according to a sixth aspect of the present invention, the control means compares the level of the output signal of the precipitation detection sensor with a predetermined reference level. When it is determined that the level is exceeded, the control of the driving unit is stopped.

[0013]

According to the first aspect of the present invention, when the diffused light passing through the light projecting window of the light projecting section is irradiated toward the light receiving section formed by the light receiving element and the lens, the lens is moved from the light receiving surface of the light receiving element to the lens. Is set to include the periphery of the opening of the light-emitting window of the light-emitting unit but not to the outside of the periphery of the opening, so that there is a possibility that disturbance light from other than the light-emitting window may enter the light-receiving surface. Disappears. According to the second aspect of the present invention, when irradiating light to a reflecting surface and irradiating the reflected light to a light receiving unit constituted by a light receiving element and a lens, the field of view seen through the lens from the light receiving surface is the reflecting surface However, since it is set so as not to include the space outside the peripheral edge portion, there is no possibility that disturbance light from outside the reflection surface enters the light receiving surface. By limiting the field of view expected to the light receiving section to the irradiation area of light for detecting precipitation, disturbance light from outside this area is prevented from entering the light receiving element, and a simple configuration is achieved. Thus, it is possible to provide a precipitation detection sensor with high detection accuracy.

According to the third aspect of the present invention, by providing a slit hole in a direction crossing the optical axis in front of the lens on the light receiving section side, a band-like light beam which becomes thinner in the optical axis direction with respect to the lens. Then, the light receiving section outputs a change in the amount of received light with respect to the band light beam. When the precipitation passes through the band-shaped light beam, the amount of light received for the band-shaped light beam changes reflecting the shape and size of the precipitation, so that the detection accuracy of the sensor can be further improved.

According to the fourth aspect of the present invention, only a signal in a predetermined frequency band based on the width of the light guided to the light receiving surface of the light receiving element, the typical size of the precipitation, and the falling speed is provided downstream of the light receiving unit. Since we have a filter to pass through,
There is no danger of erroneously detecting minute substances other than precipitation, such as dust, as precipitation, and the detection accuracy of the sensor can be further improved.

According to a fifth aspect of the present invention, the wiper control means of the vehicle is operated based on the detection result of the precipitation detecting sensor having the above-described structure, so that appropriate wiper control is performed without being affected by disturbance light. it can.

According to the present invention, when the level of the output signal of the precipitation detection sensor exceeds a predetermined reference level, the drive control of the wiper is stopped, so that the output of the sensor is disturbed by any chance. Even if noise due to light is present, there is no possibility that the wiper malfunctions.

[0018]

FIG. 1 shows a schematic configuration of a wiper control device according to an embodiment of the present invention. This wiper control device is for determining the arrival of rainfall such as raindrops and snow and automatically operating a wiper of a vehicle (not shown). And a control device 2 that controls the wiper drive circuit 15 by inputting the detection signal of In addition, the precipitation detection sensor 1 is attached to an appropriate place outside the vehicle such as on a hood, and the control device 2 is provided inside the vehicle such as an engine room.

FIGS. 2 and 3 show an example of the appearance and configuration of the precipitation detecting sensor 1. FIG. This precipitation detection sensor 1 has a light emitting unit 4 at both ends of a base 3 having a long plate shape.
The light receiving portions 5 are formed so as to protrude from the upper surface of the base 3 respectively.

The light projecting section 4 has a light projecting element 6 housed therein and a light shielding wall 8 having a light projecting window 7 of a predetermined size opened on a side facing the light receiving section 5. The diffused light is emitted from the light emitting window 7 toward the light receiving unit 5. On the other hand, a light receiving unit 35 for receiving diffused light from the light projecting unit 4 is housed inside the light receiving unit 5. The light receiving unit 35 is provided such that the lens 9 is incorporated in the open portion of the case body 11 having one open surface, and the light receiving element 10 is incorporated in the opposing surface thereof, and the open portion faces the light projecting portion 4 side. As a result, only the light passing through the lens 9 is guided to the light receiving element 10. Note that the light receiving section 5
A light-shielding wall 12 provided with a light-receiving window 13 (shown in FIG. 4) corresponding to the size of the lens 9 is also provided on the side facing the light projecting section 4.
Is deployed.

The precipitation detecting sensor 1 of this embodiment is viewed through a lens from the light receiving surface of the light receiving element 10 in order to prevent disturbance light from a place other than the light projecting section 4 from being incident on the light receiving element 10. The position of the light receiving element 10 and the light receiving position thereof are set so that the field of view (hereinafter referred to as a “probable field of view”) includes the periphery of the opening of the light projecting window 7 but does not include the light shielding wall and the external space outside the periphery of the opening. The size of the surface is set. Thereby, on the light receiving surface, of the light emitted from the light projecting window 7 of the light projecting unit 4, the light included in the expected field of view, that is, goes to the lens 9 from the periphery or the inside of the opening of the light projecting window 7. Only light will be guided.

FIG. 4 shows the relationship between the light projecting path from the light projecting section 4 and the optical system of the light receiving section 5. Here, for the sake of simplicity, the optical path of the light parallel to the optical axis of the light receiving section 5 is shown by a plurality of solid lines, and the light projecting window 7 out of the light inclined with respect to the optical axis. The optical path of the light reaching the light receiving section 5 from the vicinity of the opening periphery is indicated by a broken line. As described above, the position and size of each optical system are adjusted so that the light entering the lens 9 from near the opening edge of the light projecting window 7 enters the end of the light receiving surface 10 a of the light receiving element 10. Is limited to the inside of the light projecting window 7, and the disturbance light entering the lens 9 from outside the possible field of view, such as above the light projecting unit 4, is guided to a place other than the light receiving surface 10a.

However, also in the above configuration, when the disturbance light is reflected near the opening edge of the light projecting window 7 or in the window, the reflected light enters the light receiving element 10. Therefore, the output light amount of the light projecting element 6 is adjusted to be sufficiently larger than the minimum detected light amount of the light receiving element 10,
If the amount of disturbance light included in the light reaching 0 is extremely small, the output potential of the light receiving element 10 is maintained at a stable level. In this embodiment, in addition to the adjustment in the sensor, a function for checking whether or not the sensor output is affected by disturbance light is provided in the control device 2 as described later. It is considered that there is almost no possibility that the wiper malfunctions due to disturbance light.

When precipitation such as raindrops passes through the light emitting path of the precipitation detection sensor 1 having the above-described configuration, a part of the irradiation light is blocked by the precipitation, and the amount of light reaching the light receiving element 10 is reduced. The control device 2 recognizes the presence or absence of precipitation and the degree of precipitation based on the change in the output signal from the light receiving element 10, and outputs a drive signal to the wiper drive circuit 15 at a predetermined timing according to the recognition result.

As shown in FIG. 5, a slit plate 14 having a slit hole 14a having a predetermined thickness is formed in front of the lens 9 so that the length direction of the slit hole 14a crosses the optical axis of the lens. When disposed along the light receiving element 10, a band-like luminous flux along the optical axis direction of the light entering the light receiving window 7 from within the expected field of view comes into the light receiving element 10. Therefore, the output potential of the light receiving element indicates a change in the amount of received light with respect to the band light beam. Based on the change in the amount of light, it is possible to accurately recognize not only the presence or absence of the passage of the precipitation but also its type and size. it can. The shape of the slit hole 14a is not limited to a rectangle, and a curved slit hole that crosses the optical axis direction of the lens 9 may be formed. Instead of providing the special slit plate 14, the light receiving window 13 of the light shielding wall 12 may be formed in a slit shape.

FIG. 6 shows the principle of detecting the passage of raindrops using the above-mentioned belt-like luminous flux, and shows the change over time of the light reception rate assuming that the amount of received light is 1 when no raindrops arrive. . When raindrops at the moment the time t ₁ is assumed to have reached the strip beam, part of the light beam is shielded by the raindrops received light rate is reduced. Since raindrop can be regarded as substantially spherical, with the fall of the raindrops, the received light rate is gradually reduced drawing a curve of parabolic reflecting the shape of the raindrop, the minimum value E _min at time t ₂ the raindrop shields the entire light flux Take. Then, the light-receiving rate, raindrops gradually increases with to go out of the strip-shaped light beam, 1 at a time t ₃ when the raindrops are completely escape from the light beam
To recover.

Therefore, assuming that the raindrop is falling perpendicular to the zonal light beam, the minimum value E
Time _min and the received light rate varies T (time from time t ₁ in FIG. 6 to t ₃₎ is increased in both proportional to the diameter of the raindrop. For precipitation other than raindrops, the type and size of precipitation can be accurately recognized from the amount of change in the light receiving rate, the shape of the change, and the time of change based on the same principle. By inputting to 2, the operation of the wiper can be more accurately controlled.

Returning to FIG. 1, the precipitation detecting sensor 1
Is operated by receiving power supply from the vehicle body. A driving circuit 16 for driving the light emitting element 6 is provided on the light emitting section 4 side, and a detection signal of the light receiving element 10 is provided on the light receiving section 5 side. An I / F circuit 17 and an amplifying circuit 18 for taking out the data are respectively incorporated.

The control device 2 mainly includes a control unit 22 composed of a microcomputer, and a pre-processing unit 21 composed of a band-pass filter 19, a comparator 20, and the like is provided in a preceding stage thereof. In the band pass filter 19, as a frequency band to be passed, the light width of the diffusion optical path from the light projecting unit 4, the size (diameter of about 0.2 to 10 mm) of raindrops observed near the ground, and the falling speed ( About 2-9m / se
The frequency components around 500 to 100 kHz based on c) are set. Thereby, only the frequency components reflecting the passage of the precipitation are extracted from the output signals of the precipitation detection sensor 1 and input to the control unit 22.

When the output signal of the precipitation detecting sensor 1 is affected by strong disturbance light,
Intended for the control unit 22 is prevented from malfunctioning, is compared with a predetermined reference level L _B of the level of the output signal from the precipitation object detection sensor 1 is set in advance. The reference level L _B are those obtained by such operating advance precipitation object detection sensor 1 under standard environment, the comparator 20, for example the reference level output signal of the precipitation object detection sensor 1 L _B Is output when it exceeds H. Control unit 22, at the rise of the control signal, and stops the series of processing according to the wiper control, waits until the sensor output is returned to the reference level L _B.

For example, when the precipitation detecting sensor 1 is irradiated with strong sunlight or illumination light, reflected light from the inside of the light projecting window 7 of the precipitation detecting sensor 1 and the vicinity of the opening thereof increases, and the light receiving element 10 , The level of the amount of light reaching. Accordingly, if configured not to perform processing according to the wiper control when exceeding the output level of the reference level L _B of the sensor as described above, when the noise due to ambient light is superimposed on the output of the precipitation object detection sensor 1 Malfunction of the wiper can be avoided.

On the other hand, in a state level of the output signal of the precipitation object detection sensor 1 is equal to or less than the reference value L _B, when the signal level is reduced by a predetermined amount, the control unit 22, precipitation object is passed through the projection optical path It recognizes that rainfall has occurred and measures the amount of precipitation by integrating the amount of change in sensor output. Further, the control unit 22
Compares the measured value with a predetermined threshold value, and when a rainfall exceeding this threshold value is measured, the wiper driving circuit 1
5 to output a control signal for driving.

The wiper drive circuit 15 includes a transistor circuit 23, a relay circuit 24, a wiper motor 25, and the like.
When 3 is turned on and the contact of the relay circuit 24 is connected, a current is supplied to the wiper motor 25. Thereafter, the control unit 2
2 resets the integrated value of the precipitation amount, and thereafter receives the detection signal from the precipitation detection sensor 1 and repeatedly executes the same processing.

Each of the circuits of the preceding section 21 may be incorporated in the precipitation sensor 1. In addition, the precipitation detection sensor 1 having the above-described configuration has a configuration in which the light projecting unit 4 and the light receiving unit 5 are arranged to face each other and the diffused light is projected from the light projecting unit to the light receiving unit. A sensor configured to reflect the light from the light projecting element 6 on the reflecting surface and guide the specular component to the light receiving element 10 may be used.

FIG. 7 shows the structure of a precipitation detecting sensor 1 'of the above type. In this precipitation detection sensor 1 ′, a light emitting / receiving unit 31 is formed at one end of a base 30 in the shape of a long plate, and the same light emitting element 6 and light receiving unit 35 as in the first embodiment are accommodated therein. And the base 30
A projection 33 having the same shape as the light emitting / receiving section 31 is provided at the other end of the light emitting / receiving section 31, and a surface 32 of the projecting section 33 facing the light emitting / receiving section 31 is a reflection wall surface 32. The reflecting wall surface is formed on a rough surface so that the specular reflection component becomes strong, and each optical wall is positioned so that the light receiving element 10 is positioned in the direction in which the specular reflection component of the irradiation light from the light projecting element 6 travels. The position of the system has been adjusted. Further, the projecting portion 33 of the light emitting / receiving section 31
A light-shielding wall 34 having a light-emitting / receiving port (not shown) corresponding to the size of the light-emitting element 6 and the lens 9 is provided on the side facing the light-receiving element 6.

In the precipitation detecting sensor 1 'of this embodiment,
Although the expected field of view of the light receiving element 10 includes the peripheral portion of the reflective wall surface 32, its position and the size of the light receiving surface are set so as not to include the space outside the peripheral portion. It is configured such that disturbance light from the outside does not enter the light receiving element 10.

However, in this sensor, when disturbance light from a place other than the light projecting element 6 is applied to the reflecting wall, the diffuse reflected light is incident on the light receiving element 10, so that the precipitation It is considered that the detection sensor 1 is more susceptible to disturbance light. Therefore, the irradiation light amount of the light emitting element 6 is
It is desirable to set even larger than the precipitation detection sensor 1 of the first embodiment. This precipitation detection sensor 1 '
And the circuit configuration of the control device 2 receiving the output signal thereof is as follows:
This is the same as that shown in FIG. 1, and a detailed description is omitted here.

[0038]

According to the first aspect of the present invention, there is provided a precipitation detecting sensor, wherein a light receiving section is provided on a light projecting path of diffused light to detect precipitation passing through the light projecting path based on an output signal of the light receiving section. The part is constituted by the light receiving element and the lens, and the visual field viewed through the lens from the light receiving surface of the light receiving element includes the opening edge of the light projecting window for irradiating the diffused light, but the outside is not expected beyond the opening edge. In addition, since the size and the position of the light receiving surface are set, there is no possibility that disturbance light from outside the light emitting window is incident on the light receiving surface, and a precipitation detection sensor having a simple configuration and high detection accuracy is provided. Can be.

According to a second aspect of the present invention, in the precipitation detecting sensor, the light reflected by the reflecting wall surface is guided to the light receiving unit, and the output signal of the sensor detects the precipitation passing through the reflected light path. Since the light-receiving element and the lens are configured such that the field of view seen through the lens from the light-receiving surface of the light-receiving element includes the peripheral edge of the reflecting wall but does not include the outside of the peripheral wall, the reflection There is no possibility that disturbance light from outside the wall surface will enter the light receiving surface, and the same effect as the first aspect of the invention can be obtained.

According to the third aspect of the present invention, a slit-shaped light beam is provided in front of the lens on the light receiving portion side so as to cross the optical axis, so that the band-shaped light beam is thinned in the optical axis direction with respect to the lens. Is incident, so that the type and size of the precipitation can be accurately detected from the output signal of the light receiving unit with respect to the band-like light flux.

According to the fourth aspect of the present invention, only a signal in a predetermined frequency band based on the width of light converging on the light receiving surface of the light receiving element, the typical size of the precipitation, and the falling speed is provided downstream of the light receiving unit. Since we have a filter to pass through,
There is no danger of erroneously detecting minute substances other than precipitation, such as dust, as precipitation, and the detection accuracy of the sensor can be further improved.

According to the fifth aspect of the present invention, the driving means of the wiper of the vehicle is operated based on the detection result of the precipitation detecting sensor having the above-mentioned configuration, so that it is possible to reduce the flying state of the precipitation without being affected by disturbance light. Appropriate wiper control can be performed accordingly.

According to the sixth aspect of the present invention, the level of the output signal from the light receiving section is compared with a predetermined reference level to detect the presence or absence of disturbance light on the light receiving section. Even if disturbance light is reflected and enters the light receiving unit within the expected field of view, malfunction of the wiper can be prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a wiper control device according to one embodiment of the present invention.

FIG. 2 is a perspective view illustrating an appearance of a precipitation detection sensor.

FIG. 3 is an explanatory diagram showing a configuration of an optical system of the precipitation detecting sensor of FIG. 2;

FIG. 4 is an explanatory diagram illustrating a relationship between a light projecting path and an expected field of view of a light receiving unit.

FIG. 5 is an explanatory view showing an example in which a slit plate is arranged in front of a lens in the precipitation detecting sensor of FIG. 2;

FIG. 6 is an explanatory diagram showing a change in a light receiving rate obtained when a raindrop passes through a belt-like light beam.

FIG. 7 is an explanatory diagram showing another configuration of the precipitation detection sensor.

[Explanation of symbols]

 Reference Signs List 1, 1 'precipitation detection sensor 2 control device 4 light emitting unit 5 light receiving unit 6 light emitting element 7 light emitting window 8 light shielding wall 9 lens 10 light receiving element 10a light receiving surface 14 slit plate 14a slit hole 15 wiper drive circuit 19 band pass Filter 20 Comparator 22 Control unit 32 Reflection wall

Claims (6)

[Claims] 1. A light projecting unit in which projected light becomes diffused light,
A light-receiving unit for receiving light from the light-emitting unit is disposed opposite to the light-receiving unit at a predetermined distance, and the precipitation detecting unit detects the precipitation passing through the optical path of the diffused light based on an output signal of the light-receiving unit. In the object detection sensor, the light projecting unit is provided with a light projecting window for projecting the diffused light to the optical path at a position in front of the light source. The light receiving unit includes a light receiving element and a light receiving element. A lens for guiding light to a light-receiving surface, wherein the light-receiving element receives the light so as to include the opening edge of the light-emitting window in the field of view seen through the lens from the light-receiving surface, but not to include the outside of the opening edge. A precipitation detection sensor in which the size and position of a surface are set. 2. A light-emitting unit comprising: a light-emitting unit; a reflecting wall for receiving and reflecting light from the light-emitting unit; and a light-receiving unit for receiving light reflected from the reflecting wall. A precipitation detecting sensor configured to detect precipitation passing through the reflected light path based on the output signal of the light receiving element, wherein the light receiving unit includes a light receiving element and a lens for guiding light to a light receiving surface of the light receiving element. The size and position of the light-receiving surface are set such that the light-receiving element includes a peripheral portion of the reflective wall surface in a field of view seen through the lens from the light-receiving surface, but does not include a portion outside the peripheral portion. Precipitation sensor. 3. The precipitation detecting sensor according to claim 1, wherein the light receiving unit is provided with a slit plate having a slit hole formed in a front of the lens so as to cross an optical axis of the lens. 4. A signal subsequent to the light receiving section, wherein only an output signal of a signal in a predetermined frequency band based on a width of light guided to the light receiving surface, a typical size of precipitation, and a falling velocity is provided. 2. A filter, which is provided with a filter through which the filter passes.
3. A precipitation detection sensor according to any one of claims 1 to 3. 5. A precipitation detecting sensor according to claim 1, a driving unit for driving a wiper of a vehicle, and the driving unit is operated based on a detection result by the precipitation detecting sensor. A wiper control device comprising: 6. The control means compares the level of the output signal of the precipitation detection sensor with a predetermined reference level, and when it is determined by this comparison processing that the level of the output signal exceeds the reference level, The wiper control device according to claim 5, wherein control of the driving unit is stopped.