JPH11310096A - Image pickup device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To acquire the image data allowing an image process during the operation of a wiper at the periodic timing by setting the exposure time of an image pickup section to such as degree that the environment on the outside of a vehicle can be picked up through the image of the wiper when the operation of the wiper is detected. SOLUTION: A camera controller 103 judges whether a wiper 103 is in operation or not based on the output of a wiper switch 109. When the wiper 107 is in operation, the camera controller 103 calculates and controls the aperture, exposure time and gain of a CCD camera 101 to obtain the optimum luminosity on a screen and the prescribed exposure time or longer based on the processed result of an image processing device 102. The prescribed exposure time is set to such a value that the image of the wiper 107 is spread over the whole screen and the running scenery can be picked up through the wiper 107 when the wiper 107 enters the visual field. Even when the wiper 107 is in operation, the image data allowing an image process can be acquired.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicular image pickup apparatus for picking up an image of an external environment of a vehicle from inside a vehicle.

[0002]

2. Description of the Related Art As a conventional vehicle imaging apparatus, for example,
There is an apparatus disclosed in Japanese Patent Application Laid-Open No. 5-294193. According to this device, when the object detection means provided in a part of the vehicle detects the object information of the vehicle ahead through the windshield of the vehicle, the driving state of the wiper for cleaning the surface of the windshield of the vehicle is detected. The operation of the object detection means is controlled based on a signal from the wiper drive detection means.

According to the apparatus disclosed in Japanese Patent Application Laid-Open No. 8-72641, an image pickup means for picking up an image of the front of a vehicle, and an image for controlling the driving of the image pickup means and processing an image signal output from the image pickup means. Processing means. Further, an automatic stop signal receiving unit in which the image processing means receives an automatic stop signal from the wiper motor, an elapsed time measuring unit for measuring an elapsed time from when the automatic stop signal is received, and a wiper driven by the wiper motor The influence of the wiper is eliminated by providing an imaging control unit for inhibiting the capture of the image signal when the time is within the time corresponding to the operation of (1).

Further, according to the device disclosed in Japanese Patent Application Laid-Open No. 9-286279, the image pickup device is mounted so as to photograph the outside of the vehicle through an area wiped by the windshield wiper, and the wiper is operated. Sometimes, the image taken immediately after the wiping by the wiper is preferentially used.

According to the apparatus disclosed in Japanese Patent Application Laid-Open No. 7-81458, when the wiper is operated in rainy weather or the like, the timing control unit controls the wiper operation mode signal from the wiper controller and stops the wiper at a predetermined start position. When a stop signal indicating that the operation is being performed is input, an image capture command signal is output to the camera and the image processing unit, and after a delay time unique to each operation mode of the wiper has elapsed, the wiper controller is instructed. Output a start command signal. As a result, the wiper operates without traversing its field of view during imaging by the camera.

Further, according to the apparatus disclosed in Japanese Patent Application Laid-Open No. Hei 7-280561, a vehicle which is installed in a vehicle interior, captures external images from two different viewpoints through a windshield, and calculates the distance to an object outside the vehicle by stereoscopic vision. The distance measuring apparatus is provided with a sum forming means for calculating a sum luminance which is a sum of luminance values for each of two images taken simultaneously, and a difference forming means for calculating a sum luminance difference which is a difference between the two sum luminances. The comparing means for inputting the total luminance difference compares the total luminance difference with a reference value indicating that there is a difference in brightness between the two images to determine whether there is a difference in brightness. Each time it is determined that there is a difference in brightness, the gate unit disables the output of the two images to stop the processing of the distance calculation, thereby eliminating the influence of the wiper.

[0007]

However, these conventional vehicle image pickup devices have the following problems. That is, JP-A-5-294193, JP-A-8-72641, and JP-A-9-2862.
In the device of the '79 publication, the image from the imaging unit is not sent to the image processing unit periodically, so that the accuracy is reduced when the time derivative of the image processing result is used as information. Further, in the device disclosed in JP-A-7-81458,
If the positional relationship between the imaging unit and the part to be wiped by the wiper is different, the control timing is also different. Therefore, when applied to a plurality of vehicles of different types, it is necessary to adjust the control timing for each type of vehicle. Further, the apparatus disclosed in Japanese Patent Application Laid-Open No. 7-280561 uses two or more imaging units, and therefore cannot be applied to a system having only one imaging unit.

[0008] It is an object of the present invention to provide no special synchronization with the operation of the wiper even during the operation of the wiper.
It is an object of the present invention to provide an imaging apparatus capable of acquiring image data that can be subjected to image processing at a periodic timing and with one camera.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to FIGS. 1 and 3 showing an embodiment, in which the reference numerals for the corresponding elements are given in parentheses. To achieve the above object, an image pickup apparatus for a vehicle according to claim 1 includes an image pickup unit (101) for picking up an image of an environment outside a vehicle from a vehicle interior through a window glass (110), and a window glass (11).
0), the field of view (11) of the imaging unit (101) during operation.
1) When the wiper operation state detection unit (103) that detects the operation state of the wiper (107) that crosses the wiper (107) and the wiper operation state detection unit (103) detects that the wiper (107) is operating. When the image of the wiper (107) is captured by the image capturing unit (101), the image of the image capturing unit (101) is transmitted to the extent that the image of the wiper (107) can be transmitted and the environment outside the vehicle can be captured. An imaging control unit (103, 105) for setting an exposure time is provided. According to a second aspect of the present invention, in the imaging device for a vehicle according to the first aspect, the wiper operation state detection unit (103).
Is further detected by detecting the operation speed of the wiper (107), and the imaging control unit (103, 105) is controlled in accordance with the operation speed of the wiper (107) detected by the wiper operation state detection unit (103). The exposure time is set. According to a third aspect of the present invention, in the vehicle imaging apparatus according to the first or second aspect, the imaging control unit (10
3, 104, 105, 106) along with the exposure time,
At least one of the aperture and the gain is adjusted to set an image captured by the imaging unit (101) to an appropriate brightness.

[0010] In the section of the means for solving the above-mentioned problems, the description is made in correspondence with the drawings of the embodiment for easy understanding, but the present invention is not limited to the embodiment.

[0011]

Since the present invention is configured as described above, it has the following effects. According to the first aspect of the present invention, when the image of the wiper is captured by the imaging unit while detecting that the wiper is operating, the environment outside the vehicle can be captured through the image of the wiper. The exposure time is set so that it is approximately the same, so there is no special synchronization with the operation of the wiper, and with a simple configuration, it is possible to acquire image data that can be processed at periodic timing It is. In addition, with such a configuration, the same imaging device can be used even when the vehicle type is different. Furthermore, only one camera is required. According to the second aspect of the present invention, the exposure time that allows the image of the environment outside the vehicle to be transmitted through the image of the wiper is set in accordance with the operation speed of the wiper, so that the same effect as the first aspect is obtained. With
It is possible to acquire more accurate image data without unnecessarily lengthening the exposure time. According to the third aspect of the present invention, the exposure time is set to be long, and at least one of the aperture and the gain is adjusted to make the brightness appropriate. Can be obtained.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment FIG. 1 is a configuration diagram of a first embodiment of an imaging apparatus according to the present invention. CCD that captures (images) the scenery in front of the vehicle
A camera 101, an image processing device 102 for processing an image from the CCD camera 101, and an aperture, an exposure time,
Camera controller 10 for calculating signal for controlling gain
3, an aperture control unit 104 for controlling the aperture of the CCD camera 101; an exposure time control unit 105 for controlling the exposure time of the CCD camera 101; a gain control unit 106 for controlling the gain of the CCD camera 101; Wiper 107 for wiping raindrops and the like adhering to the windshield in the field of view of the windshield, a wiper motor 108 for operating the wiper 107, and a vehicle driver
And a wiper switch 109 for controlling the operation of the switch 7. The camera controller 103 includes a microprocessor and peripheral circuits.

Next, the operation will be described. FIG. 2 is a flowchart showing the flow of processing in the camera controller 103. In step S201, the system starts operating by a driver's operation or an ignition key of a vehicle being turned on. In step S202, it is determined from the output of the wiper switch 109 whether the wiper 107 is operating. Camera controller 103
In the above, a part of the I / O port of the microprocessor is assigned as a detection unit that can detect the state of the wiper switch 109. If it is determined that the wiper 107 is not operating, the process proceeds to step S203, and the image processing apparatus 1
02 so that the brightness of the screen is optimal from the processing result of C2.
The aperture, exposure time, and gain of the CD camera 101 are controlled (set). Thereafter, the process returns to step S202 to repeat the processing.

In step S202, the wiper 107
If it is determined that is operating, step S204
Proceed to. In step S204, based on the processing result of the image processing apparatus 102, respective values of the aperture, the exposure time, and the gain of the CCD camera 101 are calculated so that the brightness of the screen is optimized and the exposure time is equal to or longer than a predetermined time. In step S205, it is determined whether the calculated value is an appropriate value. If it is determined that the value is appropriate, step S20
6, the aperture control unit 104 and the exposure time control unit 105 set the calculated aperture, exposure time, and gain values.
And the gain control unit 106 is controlled. Step S205
If it is determined that the value is not an appropriate value, step S
Proceeding to step 207, a warning is issued, and then proceeding to step S206, where the aperture, exposure time,
The gain is controlled (set) to the calculated value. Step S2
After the process of step 06, the process returns to step S202 to repeat the process.

If the value is not an appropriate value in step S205, it means that overexposure occurs when the aperture is narrowed to the maximum and the exposure time is set to a predetermined time or more even when the gain is minimized in order to optimize the brightness of the screen. This is the case where the brightness of the screen is not optimized unless the exposure time is long enough to cause image blurring of other images even if the aperture is opened and the gain is maximized. In such a state, it is not possible to obtain appropriate image data capable of performing image processing, so that a warning to that effect is issued to the driver in step S207. The warning here is to sound a warning buzzer (not shown), notify the contents of the warning by voice, and if a display device is present, to display the contents to that effect.

FIG. 3 is a view for explaining the positional relationship between the CCD camera 101 and the wiper 107 of the windshield 110 in this embodiment. This figure shows C from the side of the vehicle.
FIG. 2 is a view of a CD camera 101 and a windshield 110. In FIG. 3, the CCD camera 101 is installed at a position where the distance from the windshield 110 is relatively short. FIG. 4 is an image when the road ahead is imaged when the wiper 107 is not operating. If the wiper 107 is operated in this state, if the above-described process of extending the exposure time to a predetermined time or longer is not performed, FIG.
As shown in FIG. 7, the image is obtained by reflecting the wiper 107 in the screen imaged in the field of view 111. In this image, the landscape of the road ahead is partially blocked by the wiper 107, so that appropriate image data of the entire screen cannot be obtained and image processing cannot be performed. Also, the CCD camera 101
Is relatively close to the wiper 107,
The wiper 107 reflects the image of the CCD camera 101 over a wide range, and the range over which image processing cannot be performed is wide.

FIG. 6 shows an image of the road ahead in the case where an exposure time longer than a proper predetermined time is set in the processing of FIG. The wiper 107 is, as shown in FIG.
The wiper image spreads over the entire screen as shown in FIG. 6 because the CCD camera 101 is wiped much closer than the running scene, so that the running scene is transmitted through the wiper image. That is, although the entire screen is slightly darkened, the image is not blocked by the wiper 107, and image data that enables image processing can be obtained.

For the predetermined exposure time in step S204, when the wiper 107 enters the field of view 111, the image of the wiper 107 spreads over the entire screen, and the running scene is imaged through the image of the wiper 107. Then, an appropriate value that allows the image processing of the captured image to be performed is determined by experiment, simulation, or the like. For example, when the wiper 107 operates in the low-speed mode,
The time from when the wiper 107 starts to appear in the field of view 111 (that is, the screen in FIG. 4) to when the wiper 107 starts to deviate from the field of view 111, or the time from when the wiper 107 starts to be imaged to when it completely departs from the field of view 111 And so on.

As described above, without special synchronization between the wiper 107 and the CCD camera 101, even if the image of the wiper is reflected on the image pickup screen, the image processing is not greatly affected. That is, even during the operation of the wiper, it is possible to acquire image data that can be subjected to image processing at a periodic timing without taking special synchronization with the operation of the wiper. Moreover, the imaging device can be easily configured with one camera.

When the vehicle image pickup device is mounted on a different vehicle model,
The positional relationship between the CCD camera and the windshield is often determined by the shape of the vehicle. FIG. 7 shows the above-described image pickup apparatus in which the positional relationship between the CCD camera and the windshield is shown in FIG.
It is a figure explaining the case where it is attached in a state different from the above.
In FIG. 3, the CCD camera 101 is the windshield 11
It was installed at a position where the distance to 0 was relatively short. However, in FIG. 7, the CCD camera 301 and the windshield 302 are installed such that the positional relationship between the CCD camera 301 and the windshield 302 is farther than in FIG. When the wiper 107 is operated in such a state, as described above, if the process of extending the exposure time to a predetermined time or longer is not performed, as shown in FIG.
An image in which the wiper 107 is reflected in a screen imaged in the visual field 111 is obtained. In this image, wiper 1
Although the width partially blocked by 07 is narrower than that in FIG. 5, similarly, image processing of the entire screen cannot be performed due to lack of information on a part of the screen.

FIG. 9 shows an image of the road ahead in the case where an exposure time longer than a proper predetermined time is set in the processing of FIG. The wiper 107 is a CCD compared to FIG.
Since the operation is performed at a distance from the camera 301, the image of the wiper is displayed on a part 304 of the screen as shown in FIG.
, And the running scene is transmitted through the image of the wiper of a part 304 thereof and captured. That is, in FIG.
Although the image of the wiper 107 spreads over the entire screen and the entire screen is slightly darkened, in FIG. 9, the image of the wiper 107 spreads over a part 304 of the screen, and only the part 304 is slightly darkened. However, a bit darker 30
Also in 4, since the scenery of the road ahead is imaged transparently, data that can be subjected to image processing can be obtained.

As described above, even if the positional relationship between the CCD camera and the windshield differs depending on the vehicle type,
By mounting an imaging device having the same setting conditions, it is possible to obtain the same effect as the above-described effect.

The predetermined exposure time in step S204 is determined in consideration of the fact that the positional relationship between the CCD camera and the windshield differs depending on the type of vehicle. At that time, as described above, the image of the wiper 107 is made to spread over the entire screen in a certain vehicle type, and the wiper 1 is used in a certain vehicle type.
The setting condition may be such that the image of 07 spreads over a part of the screen, or the setting condition may be such that the image of the wiper 107 spreads over the entire screen in all types of vehicles. That is, the degree of transmission of the image of the wiper 107 and the permissible degree of image blur of other images are grasped by experiments or the like, and the most appropriate exposure time that can be used for all types of vehicles may be set.

Second Embodiment Normally, the operating speed of the wiper differs between a low-speed or intermittent mode and a high-speed mode.
If the operating speed of the wiper is different, the degree of spread of the image of the wiper, that is, the degree of transmission is different even if the same exposure time is set in the CCD camera. In the present embodiment, an appropriate exposure time is to be set for each in consideration of the speed of the operating wiper.

The configuration of the imaging apparatus according to the second embodiment is the same as that of the first embodiment shown in FIG. 1, and therefore the description thereof is omitted, and only the flowchart showing the processing will be described below.

FIG. 10 is a flowchart showing the flow of processing in the imaging apparatus according to the second embodiment. In step S401, the operation of the system is started by the operation of the driver or the turning on of the ignition key of the vehicle. Steps S402 and S403 are common to steps S202 and S203 of the first embodiment. In step S402, it is determined from the output of the wiper switch 109 whether the wiper 107 is operating. If it is determined that the wiper 107 is not operating, the process proceeds to step S403, and the aperture, exposure time, and gain of the CCD camera 101 are controlled so that the brightness of the screen is optimized based on the processing result of the image processing apparatus 102. Then step S4
02 and the process is repeated.

In step S402, the wiper 107
If it is determined that is operating, step S404
To determine the wiper operation mode from the output of the wiper switch 109. If it is determined in step S404 that the wiper operation mode is the low-speed or intermittent operation mode, the process proceeds to step S405, where the brightness of the screen is optimized based on the processing result of the image processing apparatus 102, and the exposure time is longer than the predetermined time T1. The aperture, exposure time, and gain of the CCD camera 101 are controlled so as to be longer. Then, step S
Returning to step 402, the process is repeated. If it is determined in step S404 that the wiper 107 is operating in the high-speed mode, the process proceeds to step S406.
Of the CCD camera so that the brightness of the screen is optimal, the exposure time is longer than the predetermined time T2, and the shadow of the image of the wiper is equal to the image when operating in the intermittent / low speed mode. Controls aperture, exposure time, and gain. Thereafter, the process returns to step S402 and repeats the process.
The predetermined time T2 may be shorter than the predetermined time T1.

In the second embodiment, the processing is changed depending on the operation mode of the wiper 107. The reason why the wiper 107 operates at a high speed is that the wiper 1
This is because the exposure time may be short in order to obtain an image of the wiper 107 having the same transmittance as in the case of operating at low speed. In other words, if the exposure time is lengthened, the image to be subjected to the image processing may cause image blurring and the like, and the accuracy of the image data may be reduced. This is for obtaining sexual image data.

As for the optimum predetermined exposure time, an optimum value is set by an experiment or the like as in the first embodiment. In this manner, the same effects as those of the first embodiment can be obtained, and more accurate image data can be obtained. In the second embodiment, a warning process is not performed when the aperture, the exposure time, and the gain cannot be set to appropriate values. However, a warning process similar to that of the first embodiment is performed. You may.

In each of the above embodiments, an example has been described in which an image of the outside is taken through a windshield (front glass). However, the present invention is not limited to this. For example, when an image of the outside is taken through the rear window, the present invention can be applied to a relationship with a wiper provided in the rear window. That is, the present invention is applicable to all cases where a camera provided in a vehicle captures an image of the outside through a window of the vehicle and the window is provided with a wiper.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a first embodiment of an imaging device of the present invention.

FIG. 2 is a flowchart illustrating a flow of processing in the imaging device according to the first embodiment;

FIG. 3 is a diagram illustrating a positional relationship between a CCD camera and a windshield.

FIG. 4 is a diagram of an image when a front road is imaged when the wiper is not operating.

FIG. 5 is a diagram of an image in a case where a wiper is reflected in a screen in the relationship of FIG. 3;

FIG. 6 is a diagram of an image obtained by capturing an image of a road ahead when the processing in step S204 is performed in the relationship shown in FIG. 3;

FIG. 7 is a diagram illustrating another positional relationship between the CCD camera and the windshield.

8 is a diagram of an image in a case where a wiper is reflected in a screen in the relationship of FIG. 7;

9 is an image of an image of a road ahead in the case where the processing of step S204 is performed in the relationship of FIG. 7;

FIG. 10 is a flowchart illustrating a flow of a process in the imaging device according to the second embodiment.

[Explanation of symbols]

 101, 301 CCD camera 102 Image processing device 103 Camera controller 104 Aperture control unit 105 Exposure time control unit 106 Gain control unit 107 Wiper 108 Wiper motor 109 Wiper switch 110, 302 Windshield 111, 303 Field of view

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // B60R 1/00 B60R 1/00 A B60S 1/08 B60S 1/08 Z

Claims (3)

[Claims] 1. An image pickup unit for picking up an image of an environment outside a vehicle from a vehicle interior through a window glass, and a wiper operation state detection unit provided on the window glass and detecting an operation state of a wiper crossing a field of view of the image pickup unit during operation. When the wiper operating state detecting unit detects that the wiper is operating, and when an image of the wiper is captured by the image capturing unit, the image of the wiper is transmitted through the outside of the vehicle. An image capturing control unit that sets an exposure time of the image capturing unit to an extent that the environment can be imaged. 2. The imaging device for a vehicle according to claim 1, wherein the wiper operation state detection unit further detects an operation speed of the wiper, and the imaging control unit is detected by the wiper operation state detection unit. An image pickup apparatus for a vehicle, wherein the exposure time is set according to an operation speed of the wiper. 3. The image pickup apparatus for a vehicle according to claim 1, wherein the image pickup control section adjusts at least one of an aperture and a gain along with the exposure time to pick up an image picked up by the image pickup section. An imaging device for a vehicle, wherein the brightness is set to an appropriate value.