JPH1086796A - Detecting device for rain water drop on vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fine-sensitively and quantitatively precisely detect a rain water drop adhering to a window shield by beginning the detection of a rain water drop on the output signal of a relay plate for stopping at the reversing position of a wiper blade. SOLUTION: An area where a wiper blade W is at the standing up edge of an autostop, namely a second lower reversal positions C, C' at which the wiper blade reverses from a return path to an advance path, or at a first upper reversal positions A, A' at which the wiper blade reverses from the advance path to the return path, or near either of two reversal zones A, A' and C, C' in which the wiper blade in the wiping range of the wiper reverses is set up as the detecting domain of rain water drop detecting means by a relay plate signal input circuit. On whether the wiper blade exists in the above range or not, image data are taken in according to a process, or returned to an original detecting process again. Thus the quantity of rain water drops about equal to the quantity felt by a driver can be quantitatively precisely judged even during working of the wiper, and the accurate control of the wiper thereby becomes possible, and the structure of the wiper blade is simplified for reducing its cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a raindrop detecting device for a vehicle, and more particularly to a raindrop detecting device for a vehicle for detecting raindrops attached to a windshield in a vehicle having a wiper for reciprocatingly wiping the surface of the windshield. It concerns the device.

[0002]

2. Description of the Related Art Conventionally, there has been used an automatic wiper device which detects the attachment of raindrops to a windshield of a vehicle and automatically operates the wiper. The raindrop sensor used in such an automatic wiper device changes the resistance value when a waterdrop adheres to the substrate, detects the presence or absence of the waterdrop by the change, and recognizes the image of the glass surface from the vehicle interior. Some devices detect the presence or absence of water droplets.

In the former method, in which the presence or absence of water droplets is detected by a change in the resistance value, a part of the electric circuit is always exposed to the outside, so that not only the contamination becomes a problem but also the maintenance is troublesome. Attention has been paid to the latter type of raindrop detecting device based on image recognition (for example, Japanese Utility Model Publication No. 63-252).
No. 52).

[0004]

However, if the image of the transmitting glass surface is taken as it is, the image of the wiper blade is also taken at the same time as, for example, the operation of the wiper, which makes it difficult to extract the image of only raindrops.

Therefore, as disclosed in, for example, Japanese Patent Application Laid-Open No. 8-72641, it is sufficient to prohibit image capture when the wiper blade passes, but in reality, the position and detection timing of the raindrop sensor are not appropriate. Cannot accurately detect raindrops. For example, even if an image is captured immediately after wiping with a wiper blade, almost no raindrops can be detected,
Even if it can be detected, the rainfall cannot be determined quantitatively. Conversely, if an image is captured immediately before wiping with the wiper blade, the amount of raindrops attached may be too large and the raindrops may flow, and the amount of rainfall cannot be quantitatively determined as described above. During the operation of the wiper, the approximate center of the wiper wiping range is the center of the driver's and passenger's view. Therefore, it is preferable to detect the amount of raindrops adhering to this position, but it is difficult to detect the amount of raindrops adhering to this position since the raindrop detection device is actually provided at this position, obstructing the field of view. .

The present invention solves the problems of the prior art and can always detect raindrops adhering to a windshield with high sensitivity and quantitative accuracy.
Moreover, it is an object of the present invention to provide a vehicle raindrop detecting device having a simple structure.

[0007]

SUMMARY OF THE INVENTION According to the present invention, there is provided a vehicle for detecting raindrops attached to a windshield in a vehicle having a wiper for reciprocatingly wiping the surface of the windshield. A raindrop detecting device for detecting the vicinity of one of two reversing positions where the wiper blade is reversed in the wiping range of the wiper, and the wiper blade being the other of the reversing positions. Means for detecting that the windshield has passed the position, and when the wiper blade has passed the other reverse position, the raindrop detecting means detects raindrops attached to the windshield by the raindrop detecting means. This is achieved by providing a device. At the approximate center of the wiping range of the wiper, that is, at the center position of the driver's field of view, in the reciprocating swing of the wiper blade, the timing from the wiping on the outward path to the wiping on the return path and the wiping on the return path to the wiping on the outward path. Becomes substantially equal. That is, the maximum value of the amount of raindrops attached is equal to a half cycle of the reciprocating swing motion of the wiper blade, and this is the amount of raindrops felt by the driver.
By detecting this amount, an appropriate amount of raindrop can be determined. The cycle at which the wiper blade moves from one reversing position to the other reversing position is also a half cycle of the reciprocating swing motion of the wiper blade. Therefore, during the operation of the wiper, if raindrops are detected near the one reversing position when the wiper blade is at the other reversing position, it is possible to detect the amount of attached raindrops for one half cycle of the reciprocating swing motion of the wiper blade.

In particular, the one reversing position comprises a first reversing position where the wiper blade reverses from the forward path to the backward path, and the other reversing position comprises a second reversing position where the wiper blade reverses from the backward path to the forward path. Preferably, the means for detecting the second reversing position comprises a signal sensor for detecting a signal based on an operation of a relay plate for stopping the wiper blade at the second reversing position when the wiper stops. A motor drive / stop signal is always output by a relay plate for stopping the wiper blade at the second reversing position (lower storage position), and the detection of this signal is used to start detection of raindrops. Thus, it is not necessary to separately provide a sensor or the like for detecting the position of the wiper blade.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 shows a schematic configuration of a vehicular raindrop detecting device constituted by an image recognition device according to the present invention. A CCD camera 2 for inputting an image is provided on the rear side of the rear-view mirror 1 in the cabin of the vehicle. Also,
A screen 4 is provided at a position within the wiping range of the wiper W in the upper center of the windshield 3 and facing the CCD camera 2 so as not to obstruct the occupant's view (FIG. 2). The position of the screen 4 is determined by setting the upper inversion position where the wiper blade W is inverted from the forward path to the backward path as the first position.
And the lower inversion position where the wiper blade W reverses from the return path to the outward path is the second reversal position C,
C 'is near the first inversion position A'.

The screen 4 is made of a translucent film, such as milky frosted glass, in which light (image) from the front, which is separated from the screen, is dispersed and the image near the screen is relatively sharp. , Is attached to the windshield 3 on the vehicle interior side. A hood 5 is provided between the CCD camera 2 and the windshield 3 (screen 4) so as to block light from the side or top and bottom and to efficiently input only the image on the screen 4 to the CCD camera 2. . Note that the CCD camera 2 is connected to an image processing device 6, which is connected to a wiper driving device (not shown).

FIG. 3 shows a drive circuit of the motor 10 for operating the wiper blade W. The motor 10 has a power supply side terminal, a high-speed drive terminal, and a low-speed drive terminal,
The power supply side terminal is connected to the power supply, and the high-speed and low-speed drive terminals are connected to the high-speed / low-speed switching relay switch 11. The power supply side terminal of the motor 10 is also connected to the terminal T1 of the three terminals of the relay plate 12. The constant connection terminal T2 of the remaining two terminals of the relay plate 12 is connected to the drive / stop relay switch 13 of the motor 10, and the other terminal T3 is grounded. The relay plate 12 rotates in conjunction with the motor 10, and connects or grounds the relay switch 13 to a power supply terminal of the motor 10 according to the rotation angle. That is, when the drive / stop relay switch 13 is on (grounded), the motor 10 rotates independently of the relay plate 12, but
When the drive / stop relay switch 13 is turned off, the relay plate 12 is moved to the second position in which the wiper blade W is stored.
A so-called auto-stop mechanism for driving and stopping the motor 10 until the rotation angle (position shown in the drawing) corresponding to the reversal positions C and C ′ of FIG.

Further, the constant connection terminal T2 of the relay plate 12 is also connected to the relay plate signal input circuit 14,
The change in the potential of the constant connection terminal T2 is input to the image processing device 6 as a signal, and the image processing device 6 captures an image in accordance with the signal, determines the presence / absence of raindrops, the amount of adhesion, and the like. It is designed to be driven.

The operation of this embodiment will be described below with reference to FIGS. In the flowchart of FIG. 4, the flow of steps 1 to 7 indicates the flow when the normal wiper is not operated and the intermittent operation is performed, and the flow of steps 1, 8 and 7 indicates the flow when the wiper is operated at low speed or high speed. First, in step 1, it is determined whether or not the rising edge of the auto stop is detected by the relay plate signal input circuit 14, and if not detected, that is, the wiper blade W is moved to the second inversion position C,
If no signal passing C 'is obtained, step 2
To determine whether or not the wiper blade W is in the auto-stop area, that is, in the second reversing position C or C '. If the wiper blade W is not in the auto-stop area, the procedure returns to step 1; It is determined whether or not a predetermined time has elapsed after the reset, and if not, the timer is further counted up in step 4 and the process returns to step 1. If a certain time has elapsed since the last time the timer was reset, the timer is reset in step 5 and the image data is fetched in step 6. Then, proceed to Step 7,
It is determined whether or not the amount of the operating raindrop is in accordance with a predetermined determination condition, and the motor 10 is actually operated in accordance with the determination result, and the process returns to step 1. Here, a more accurate determination can be made by setting a determination condition that also incorporates the current operating state of the wiper.

For example, when the wiper blade W, that is, the motor 10 is stopped at the present time, or when the motor 10 is intermittently operated, the timing at which the image is taken almost depends on the set time of the timer, but the wiper blade W is currently operating at high speed or low speed. In this case, the timing of capturing an image is almost at the time of detecting the rising edge of the auto stop. This is shown in the time chart of FIG. The first stage in the figure is the position of the reciprocatingly oscillating wiper blade W, the second stage is the timing at which the wiper blade W is reflected on the camera 2, and the third stage is on the windshield 3 wiped by the wiper blade W. 4 shows the change in the amount of raindrops adhering to the raindrop detection area by the camera 2, and the fourth row shows the input signal to the relay plate signal input circuit 14, that is, the image capture signal. Further, the positions M and N of the fourth stage correspond to the relay plate signal input circuit 1.
4 is the rising edge of the auto stop due to the input signal of No. 4. The broken line in the third row indicates a change in the amount of raindrops attached to the raindrop detection area when the camera 2 is provided in the areas B and B '.

Here, as described above, the reciprocating swing of the wiper blade W is substantially at the central portion of the wiping range of the wiper (B, B 'in FIG. 2), that is, at the center of the driver's field of view. The timing from the wiping on the forward path to the wiping on the return path is substantially equal to the timing from the wiping on the return path to the wiping on the forward path. That is, the maximum value of the amount of the attached raindrops is a half cycle of the reciprocating swing motion of the wiper blade W. However,
Regions B and B 'in FIG. 2 because they hinder the driver's view.
It is difficult to provide a raindrop detecting device in a yard. Therefore, in order to detect an amount equivalent to the amount of raindrops adhering to the regions B and B ', in the present embodiment, the wiper blade moves to the other reverse position during the high-speed or low-speed wiper operation except for the intermittent operation. At one time, by detecting raindrops near one reversal position, the amount of attached raindrops for one half cycle of the reciprocating swing motion of the wiper blade is detected.

Next, the procedure of the raindrop identification processing of the captured image will be described with reference to FIGS. First, an image is captured in step 11. At this time, a water drop R and dust D other than the water drop are set on the surface of the glass to be detected.
The signals of the water droplet R and the dust D also appear in the captured waveform. The waveform that appears at the beginning of one cycle is preset in the CCD camera itself, and the actual image signal is in the range of S. Next, the captured waveform is smoothed (step 12) to remove fine noise. Then, a differentiation process (step 13) is performed to calculate the amount of change in the input waveform, a threshold process (step 14) is performed to obtain binary data, and the presence or absence of water droplets and dust and the amount thereof are determined. Thereafter, the wiper control is performed by determining the wiper wiping mode as needed from the detection signal. However, since this signal includes the signal of the dust D, erroneous recognition of water droplets may be caused as it is. I will. Therefore, since the amount of change of the signal of the dust D is larger than that of the water drop signal, the signal of step 14 and the signal after the smoothing processing of step 12 are subjected to threshold processing (step 15) using a preset value (step 15). By taking the logical product of the processed signal (step 16) and the value of the dirt D (step 17), binarized data of only pure water droplets can be obtained.

FIG. 8 is a comparison of the input signals to the CCD camera when a different image is captured using the above-mentioned screen (a) and when another image is directly captured without using the screen (b). In FIG. 8A, the change of only the water droplet is clearly shown, but in FIG. 8B, the influence of the signal due to the outside scenery is great, and it is difficult to judge the change of the water droplet because of the hindrance. I understand.

In the above embodiment, the upper first inversion position A 'is set as the detection area (screen). However, as shown by an imaginary line in FIG. 2, the first inversion position A' may be used. In that case, it is necessary to change the installation position of the camera. Also,
The detection area (screen) is shifted to the lower second inversion position C,
It may be C '. In this case, in addition to changing the installation position of the camera, it is necessary to separately provide a limit switch or a sensor for detecting that the wiper blade is at the first reversal position A, A '. When a screen is provided at the lower second reversal position C, for example, as shown in FIG.
Embedding the D camera 2 in the dashboard 7 does not hinder the passenger's view.

In the above-described embodiment, the wiper device in which the two wiper arms reciprocate in the same direction has been described. However, the present invention is not limited thereto. The present invention can be similarly applied to a moving opposing wiping type wiper device, a wiper device having a single wiper arm, and the like.

[0021]

As described above, according to the present invention, in order to detect raindrops attached to the windshield of the vehicle, the vicinity of one of two reversing positions where the wiper blade is reversed in the wiping range of the wiper. Is the detection area of the raindrop detecting means, and when it is detected that the wiper blade has passed the other reversing position, the raindrop attached to the windshield is detected, so that even when the wiper is activated, the raindrop amount that is substantially equal to the raindrop amount felt by the driver Can be quantitatively and accurately determined, and accurate control of the wiper can be performed. Further, by detecting the drive / stop signal of the motor from the relay plate for stopping the wiper blade at the second reversing position (the lower storage position), the detection of the raindrop is started, so that the wiper blade is separately provided. Since there is no need to provide a sensor or the like for detecting the position of
The structure is simplified and the cost is reduced.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a main part of a vehicle, showing a schematic configuration of a vehicle raindrop detecting device according to the present invention.

FIG. 2 is a front view of a main part of the vehicle shown in FIG. 1;

FIG. 3 is a drive circuit diagram of a wiper motor for operating a wiper blade.

FIG. 4 is a flowchart illustrating a main processing flow of the raindrop detection device according to the present invention.

FIG. 5 is a time chart showing the timing of detecting the amount of attached raindrops.

FIG. 6 is a flowchart illustrating a procedure for detecting a water drop from a captured image.

FIG. 7 is a diagram showing a change in a signal waveform associated with each process of the flow in FIG. 6;

8A is a line data of an image input by a CCD camera of a vehicle raindrop detection device to which the present invention is applied, and FIG. 8B is an image line data input by a conventional vehicle raindrop detection device CCD camera. Image line data.

FIG. 9 is a view similar to FIG. 1 showing another embodiment of the vehicle raindrop detecting device constituted by the image recognition device according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 room mirror 2 CCD camera 3 windshield 4 screen 5 hood 6 image processing device 7 dashboard 10 motor 11 high-speed / low-speed switching relay switch 12 relay plate 13 motor drive / stop relay switch 14 relay plate signal input circuit W wiper T1 , T2, T3 terminals

Claims (2)

[Claims] 1. A raindrop detecting device for a vehicle for detecting raindrops attached to a windshield in a vehicle having a wiper that performs a reciprocating wiping operation on a surface of the windshield, the wiper being located within a wiping range of the wiper. A raindrop detecting unit having a detection area near one of the two reversing positions where the wiper blade is reversed; and a unit for detecting that the wiper has passed the other of the reversing positions. A raindrop detecting device for a vehicle, wherein the raindrop detecting means detects raindrops attached to the windshield after passing through the other reverse position. 2. The first reversing position wherein the one reversing position is a first reversing position where the wiper blade reverses from the forward path to the backward path, and the other reversing position is the second reversing position where the wiper blade reverses from the backward path to the forward path. Wherein the means for detecting the second reversal position comprises a signal sensor for detecting a signal based on an operation of a relay plate for stopping the wiper blade at the second reversal position when the wiper stops. The raindrop detecting device for a vehicle according to claim 1, wherein: