JP2001233139A - Fitting structure and displacement adjusting device for on-vehicle preview sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new fitting structure for a preview sensor giving no sense of incompatibility to a driver. SOLUTION: This fitting structure for the on-vehicle preview sensor is provided with a roof rail 1a fitted to the roof section of a vehicle body and extended in the vehicle length direction and the preview sensor 2a monitoring the situation in the front of a vehicle. The preview sensor 2a is installed at the tip section on the vehicle front side of the roof rail 1a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure of a vehicle-mounted preview sensor and a device for adjusting a displacement thereof.

[0002]

2. Description of the Related Art In recent years, a pair of in-vehicle cameras incorporating a solid-state imaging device (CCD), that is, a stereo-type outside monitoring device using a stereo camera has attracted attention. The monitoring device recognizes a running situation ahead of the host vehicle based on a pair of images captured by a stereo camera. And
It alerts the driver according to the recognition result and performs vehicle control such as deceleration by downshifting. In particular,
First, a positional shift of the same object shown in a pair of captured images, that is, parallax is specified (stereo matching). From the principle of triangulation, this parallax corresponds to the distance to the object. Then, based on the parallax and the two-dimensional position on the image plane, three-dimensional information in front of the vehicle, for example, a three-dimensional shape (curve or undulation) of the road or an inter-vehicle distance from the own vehicle to a preceding vehicle is obtained. You can ask. Conventionally, stereo cameras with cameras assembled on the left and right in the vehicle width direction,
In the vicinity of the rearview mirror in the vehicle cabin, it is attached to a vehicle body member such as a front rail.

[0003]

However, when a stereo camera is mounted near the rearview mirror, some drivers may feel uncomfortable.

Further, when a stereo camera is mounted in a vehicle cabin, there is a problem that the mounting interval between the left and right cameras, that is, the camera base line length cannot be set too large. The camera base length varies to some extent due to a camera mounting error, a dimensional error of the vehicle body, and the like. At this time, if these errors are substantially the same, the larger the camera base line length is, the smaller the variation in the calculated distance is, so that the monitoring accuracy is improved. However, when a stereo camera is installed in a vehicle cabin, it is difficult to increase the camera base line length in view of securing the visibility in front and the wiping area of the wiper. As a result, there is a limit to improving the accuracy of the distance calculated by the stereo method.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a mounting structure of a vehicle-mounted preview sensor which does not give a driver an uncomfortable feeling.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a first aspect of the present invention monitors a roof rail attached to a roof portion of a vehicle body and extending in a vehicle length direction, and a condition in front of the vehicle. In the mounting structure of the vehicle-mounted preview sensor having the preview sensor, the preview sensor provides a mounting structure of the vehicle-mounted preview sensor installed at the front end of the roof rail on the vehicle front side.

Here, in order to house the preview sensor inside, a cover attached to the tip of the roof rail is further provided, and the space in the cover forms a part of a ventilation passage for ventilating the vehicle interior. Is preferred.

The preview sensor is a stereo camera composed of a pair of cameras. One of the cameras is installed at a front end of one roof rail on the vehicle front side, and the other of the preview sensors is It is desirable to be installed at the front end of the other roof rail on the vehicle front side.

According to a second aspect of the present invention, there is provided an apparatus for adjusting the displacement of an in-vehicle preview sensor for obtaining a captured image by capturing a situation in front of a vehicle. A pair of light-emitting sources mounted in the field of view, and based on a captured image of a state in which the light-emitting source pair emits light, detects a shift in the mounting position of the preview sensor,
Provided is an apparatus for adjusting a positional shift of a vehicle-mounted preview sensor, the apparatus including: an image processing unit that performs image conversion processing on a captured image so that the detected shift is reduced.

Here, the light emitting source is preferably an infrared light emitting device.

Preferably, the light emitting source pair is a pair of fender markers attached to the front of the vehicle body.

Further, an ornament which is attached to a central portion in front of the vehicle body and has a light emitting source may be provided. In this case, the image processing unit detects a shift in the mounting position of the preview sensor based on a captured image of the state in which the ornament emits light.

Further, it is preferable that the above-mentioned preview sensor is a stereo camera composed of a pair of cameras.

[0014]

FIG. 1 is an external perspective view of a vehicle equipped with a roof rail. Roof rails 1a and 1b extending in the vehicle length direction are provided on left and right sides of a roof panel of the vehicle body.
Is attached. A right camera 2a is installed at the front end of the right roof rail 1a in front of the vehicle, and a left camera 2b is installed at the front end of the left roof rail 1b. The left and right cameras 2a and 2b that constitute the stereo camera include a roof rail 1
Although they are mounted separately from the roof rails 1a and 1b, they have a shape integral with the front end portions of the roof rails 1a and 1b in order to ensure an aesthetic appearance. The stereo camera is a preview sensor that monitors the situation in front of the vehicle, and has a built-in image sensor. As is well known, a stereo camera captures an image of an object from different positions, and the distance to the object can be specified based on the parallax of the object shown in a pair of captured images. On the other hand, a fender marker 3 which is a light source
a and 3b are attached. As described later, these fender markers 3a and 3b are attached to the cameras 2a and 2b, respectively.
It has a role of giving a positional reference when adjusting the positional deviation of b.

FIG. 2 is a cross-sectional view of a main part showing the vicinity of the front ends of the roof rails 1a and 1b. Note that the left and right roof rails 1a and 1b have the same cross-sectional shape in the vicinity of the distal end portions, and hence the left and right roof rails 1a and 1b are collectively represented by reference numeral 1 and the left and right cameras 2a and 2b.
b is generically represented by reference numeral 2. The roof rail 1 is fixed to a roof panel 4 of a vehicle body by bolts and nuts. The joint between the roof rail 1 and the roof panel 4 is provided with packings 5a, 5a to prevent rainwater or the like from entering.
b. On the other hand, an outer cover 6 having a shape integral with the front end is attached to the front end of the roof rail 1. The joints with the roof rail 1 and the roof panel 4 are provided with packings 5c and 5c.
Each is sealed with d. The outer cover 6 has a ventilation opening for ventilating the inside, and a camera unit main body including a semiconductor element, an electronic device, and the like is housed in the inner space.

The camera unit has a base 7, a CCD
8, interface unit 9, inner case 10, C
It is composed of a CD subcase 11. On the pedestal 7 fixed to the roof panel 4 with bolts and nuts,
The interface unit 9 is attached, and the unit 9 is covered with an inner case 10. Thus, by providing the inner case 10 separately from the outer cover 6 and forming a slight space between these members, the electronic device in the interface unit housed in the inner case 10 can be used during vehicle use. Makes it difficult to be placed in a high temperature environment or a low temperature environment. A CCD sub-case 11 is mounted on the front side of the inner case 10 in the vehicle. The sub-case 11 is equipped with a CCD 8 whose light-receiving surface faces the front of the vehicle.

In order to secure the field of view of the camera, in other words, a window 12 made of transparent glass or the like is arranged in front of the light receiving surface of the CCD 8 so as not to hinder light reception on the light receiving surface of the CCD 8. The window 12 is made of a transparent glass or the like that opens a part of the outer cover 6 and is fitted in the opening. The outside of this glass is coated with a coating such as a titanium oxide coat or a fluorine coat in order to prevent poor visibility due to raindrops and dust. In place of such a coating process, a hydrophilic film, a water-repellent film, or the like may be attached. Further, a heat ray reflection coat is applied to the inside of the glass. The space enclosed by the window 12 and the CCD sub-case 11 is filled with dry air or the like. Note that a small wiper driven by a motor or the like may be attached to the outside of the window 12 in order to secure the camera view.

On the other hand, the pedestal 7 has two ventilation ports 14a,
14b is formed. The ventilation port 14a is connected to the hose 15
Through an air inlet 18 provided in the interior trim 17. On the other hand, the ventilation port 14b is connected to the hose 1
6, and communicates with a blower fan negative pressure section of an air conditioner (not shown). In a state where a negative pressure is generated in the negative pressure portion, air (atmospheric pressure) in the vehicle compartment is sucked from the air intake 18, and the ventilation passage formed by the hose 15, the housing space of the camera unit main body, and the hose 16. Flowing inside. Accordingly, even in an environment where the temperature of the storage space of the camera unit main body is likely to increase due to direct sunlight or the like, it is possible to suppress the storage space from becoming hot.

In particular, a small fan may be installed in the storage space of the camera unit main body as a measure against high temperature when the vehicle is left in the summer. In this case, the small fan is driven in accordance with the internal temperature detected by the temperature sensor to radiate heat in the storage space. As a result, a situation in which the airflow flowing in the ventilation passage described above does not occur (when the air conditioner is not operating)
In this case, the heat radiation of the storage space can be appropriately performed. In addition, it is preferable to use a solar battery or the like that can secure a power supply even when the vehicle is left unattended, as a power supply for the small fan.

The optical information detected by the CCD 8 is converted into an electric signal. The electric signal output from the CCD 8 is subjected to predetermined signal processing in the interface unit 9 and then transferred to the image recognition unit 20 shown in FIG. The image recognition unit 20 recognizes a three-dimensional object and the like including a road shape ahead of the vehicle and a preceding vehicle based on a pair of captured images obtained from a stereo camera, using both a distance measurement technique by a stereo method and an image recognition technique. I do. The details of the recognition method are described in, for example, Japanese Patent Application Laid-Open No. 5-26547.

As described above, in the stereo camera mounting structure as described above, the stereo camera conventionally installed in the vehicle compartment is installed on the roof of the vehicle body. Therefore, since the projection in the vehicle cabin due to the stereo camera can be eliminated, the driver does not feel uncomfortable.

Further, it is possible to set the camera base length to be longer than that of a conventional mounting structure in which a stereo camera is mounted in a vehicle cabin. As described above, variations in the camera base line length caused by mounting errors of the left and right cameras 2a and 2b and dimensional errors of the vehicle body shape appear as errors in the calculated distance due to the characteristics of the stereo method. At that time, if the mounting error, dimensional error, etc. are about the same,
The larger the camera base line length, the smaller the variation in the calculated distance. Therefore, in order to improve the accuracy of the calculated distance, it is advantageous to increase the camera base line length. In the mounting structure according to the present embodiment, a camera base length substantially equal to the mounting interval between the roof rails 1a and 1b can be secured, so that it is possible to improve the accuracy of monitoring outside the vehicle as compared with the conventional mounting structure. Become.

Further, since the stereo camera is mounted on the roof of the vehicle body, which is higher than the rear-view mirror, the monitoring accuracy for distant and nearby locations can be improved. In a situation where the vehicle is traveling on a road or a highway with a height difference, the visibility of a distant place is improved by increasing the installation position of the stereo camera, and a distant preceding vehicle can be recognized. Further, the blind spot in the immediate vicinity of the host vehicle can be reduced by the height of the mounting position.

Further, since the rigidity of the stereo camera can be improved, it is possible to reduce blurring of the images taken by the cameras 2a and 2b. Originally, roof rail 1
The body members a and 1b are designed to mount heavy objects, and the rigidity of the vehicle body members at the locations where the roof rails 1a and 1b are attached is also high. Therefore, if a stereo camera is attached to such a high rigidity portion, image blurring of the camera can be reduced, and a decrease in monitoring accuracy can be suppressed. In addition, the external shape of the stereo camera, that is, the shape of the outer cover 6 is changed to the roof rails 1a, 1b.
Because it has an integral shape, it does not impair the aesthetic appearance. In addition, it is advantageous in terms of design or option setting as compared with the conventional mounting structure.

In the above description, the case where a stereo camera is used as the preview sensor has been described.
INDUSTRIAL APPLICABILITY The present invention is suitable for, but not limited to, a stereo camera mounting structure, and is widely applied to various preview sensors (including laser and millimeter wave sensors) for monitoring the situation in front of a vehicle. Of course it can be applied.

Next, a description will be given of a method of detecting a displacement of the mounting position of the stereo camera and an adjusting method thereof. As described above, the accuracy of the distance calculated by the stereo method depends on the mounting accuracy of the stereo camera and the dimensional accuracy of the vehicle body. However, the mechanical processing accuracy is lower than the accuracy required for appropriately performing the distance measurement by the stereo method. Therefore, by capturing an image of an object (for example, a test chart or the like) placed at a known distance, the displacement of the position of the stereo camera is detected, and the displacement is equivalently corrected by image conversion processing such as affine transformation. A method has been proposed (for example, see Japanese Patent Application Laid-Open No. 10-30735).
No. 2). In this embodiment, the fender marker 3
The position shift of the stereo camera, that is, the direction and the inclination are adjusted by emitting the light beams a and 3b.

FIG. 3 is a diagram for explaining the detection of a positional shift using the fender markers 3a and 3b. Left and right fender markers 3a, 3b based on the stereo camera
Is known, and each fender marker 3a, 3b is
Light bulb 21 and LED 22 that emits infrared light (colorless LE
D). The light bulb 21 lights up in conjunction with a lighting switch such as a headlight. On the other hand, LED22
Blinks when an instruction to adjust the position of the stereo camera is issued. At that time, the image recognition unit 20 blinks the left and right LEDs 22 at a light emission timing shifted by a half cycle.
Thereby, based on the captured images of the cameras 2a and 2b,
The image recognition unit 20 includes the left and right fender markers 3a,
3b can be determined without being erroneously recognized, and is less susceptible to disturbances such as sunlight. In order to accurately detect the fender markers 3a and 3b shown in the captured image, as shown in FIG.
A lens portion 23 is formed on each of a and 3b so that the infrared light of the LED 22 has directivity. The directivity peak is set so as to face the stereo camera.

Hereinafter, the displacement adjustment will be described by taking the right camera 2a as an example, but the same processing is performed for the left camera 2b. FIG. 5 is a diagram showing a search range S1 of the fender marker 3a in the captured image. An effective area R2, which is a target area for monitoring the driving situation, is set in a region excluding the end of the entire area R1 of the captured image. The right fender marker 3a is displayed at the target position T if no displacement of the right camera 2a occurs.
However, actually, the fender marker 3a is projected at a position shifted from the target position T due to an attachment error of the camera 2a or the like. Therefore, in a state immediately after the camera 2a is attached (at the time of system initialization), a relatively wide range centering on a preset target position T (appropriate position) and taking into consideration the maximum possible shift amount, Set as search range S1. The image processing unit 20 specifies the imaging position (two-dimensional coordinates on the image plane) of the right fender marker 3a emitting infrared light by searching the search range S1. FIG. 5 shows a state in which the camera 2a faces left with respect to the target direction.

When the position where the right fender marker 3a is projected (imaging position) is specified, the image recognition unit 20
Performs image transformation such as affine transformation on the captured image. That is, the imaging position of the right fender marker 3a and the target position T
The effective area R2 is shifted in the horizontal / vertical directions so that (a coincidence point P) matches (see FIG. 6). Next, the position of the left fender marker 3b is specified by searching within a predetermined search range S2 set based on the coincidence point P. Since the interval between the left and right fender markers 3a and 3b is known, if the coincidence point P is specified, the position of the left fender marker 3b is also generally specified. Therefore, the search range S2 is set in consideration of the maximum shift amount that can actually occur (particularly, the shift amount in the rotation direction around the coincidence point P). FIG. 6 shows a state where the mounting position of the camera 2a is shifted clockwise.

When the position where the left fender marker 3b is projected is specified, the image recognition unit 20 performs image conversion such as affine conversion on the captured image. That is, the effective area R2 is rotated counterclockwise around the coincidence point P (see FIG. 7). Then, an area where the line connecting the position of the left fender marker 3b and the coincidence point P is parallel to the horizontal line (not the horizontal line of the pixel) of the effective area R2 is set as the final effective area R2.

FIG. 8 is a diagram showing the effective area R2 finally set by the above-described adjustment. As described above, the displacement of the mounting position of the camera 2a is equivalently corrected by performing a linear image conversion process (typically, an affine conversion) on the captured image based on the imaging positions of the fender markers 3a and 3b. be able to. In addition,
By tilting the effective area R2, the horizontal direction of the effective area R2 does not match the horizontal pixel arrangement direction. Therefore, when scanning the image in the effective area R2 in the horizontal direction, the image recognition unit 20 scans each pixel in a saw-tooth manner as shown in FIG.
The data of each pixel is handled as data on the same horizontal line (FIG. 2B).

After the adjustment at the time of the system initial operation is completed, the imaging positions of the fender markers 3a and 3b do not usually change significantly. Therefore, thereafter, relatively narrow search ranges S3 and S4 are set based on the current imaging positions of the fender markers 3a and 3b,
In each of the search ranges S3 and S4, the fender markers 3a,
3b may be searched for. Since the amount of calculation required for these searches is relatively small, it is possible to adjust the positional deviation of the cameras 2a and 2b in real time in parallel with the monitoring control.

As described above, in the position shift adjusting method according to the present embodiment, the fender markers 3a and 3b fixedly mounted at known positions on the vehicle body are prepared without preparing a special test chart or adjustment pattern. Used. Since the imaging positions of the fender markers 3a and 3b viewed from the stereo camera are always the same regardless of the running conditions,
If the effective area is set based on these imaging positions, it is possible to appropriately correct the positional shift of the stereo camera.

Further, L in the fender markers 3a, 3b
Since the infrared light emitted from the ED 22 is the light with the highest sensitivity of the CCD 8, the fender marker 3
The positions of a and 3b can be accurately detected. In particular, if the infrared light has directivity, it is hardly affected by disturbance such as sunlight. Further, since a human cannot detect infrared light, even if the infrared light is emitted (blinks) during traveling, the driver does not feel uncomfortable. In addition, instead of the fender markers 3a and 3b,
A telescopic cornering marker or the like may be used.

Further, an ornament having an infrared light emission source may be attached to a central portion in front of the vehicle body (near the center of the left and right fender markers 3a, 3b). in this case,
Using the three points of the imaging position of the ornament that emits light and the imaging positions of the left and right fender markers 3a and 3b, the deviation of the mounting position of the camera is adjusted. As a result, it is possible to further improve the accuracy of the positional deviation adjustment.

The above-described position shift adjustment method is not limited to a stereo camera, but is widely applied to an image sensor (including a monocular camera) that can detect light emitted from a light source that provides a position reference. It is possible.

[0037]

As described above, according to the present invention, the vehicle-mounted preview sensor is attached to the front end of the roof rail, so that the driver does not feel uncomfortable.
Further, in particular, if a stereo camera is mounted using the mounting structure according to the present invention, the camera base length can be increased as compared with the case where the stereo camera is mounted in a vehicle cabin. It is possible to increase the reliability of information.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a vehicle equipped with a roof rail.

FIG. 2 is a cross-sectional view of a main part showing a vicinity of a front end of a roof rail.

FIG. 3 is an explanatory diagram of position shift detection using a fender marker.

FIG. 4 is an explanatory diagram of directivity of infrared light.

FIG. 5 is a diagram showing a search range in a captured image;

FIG. 6 is a diagram showing an effective area shifted in the horizontal / vertical directions.

FIG. 7 is a diagram showing an effective area shifted in a rotation direction.

FIG. 8 is a diagram showing an effective area finally set by adjustment;

FIG. 9 is an explanatory diagram showing the handling of data on one horizontal line when the effective area is rotated.

[Explanation of symbols]

1a, 1b roof rail, 2a, 2b camera, 3a, 3b fender marker, 4 roof panel, 5a, 5b, 5c, 5d packing, 6
Outer cover, 7 pedestals, 8
CCD, 9 interface unit, 10
Inner case, 11 CCD sub case, 1
2 windows, 13 harnesses,
14a, 14b vent, 15, 16 hose,
17 interior trim, 18 air intake, 20 image recognition unit, 21 light bulb, 22 LED, 23 lens unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // H04N 13/02 G06F 15/64 320A

Claims (8)

[Claims] 1. A mounting structure of an on-vehicle preview sensor mounted on a roof portion of a vehicle body and having a roof rail extending in a vehicle length direction and a preview sensor for monitoring a situation in front of the vehicle. Is a mounting structure of a vehicle-mounted preview sensor, which is installed at a front end of the roof rail on a vehicle front side. 2. The vehicle according to claim 1, further comprising: a cover attached to the front end of the roof rail to accommodate the preview sensor therein, wherein a space in the cover defines a part of a ventilation passage for ventilating a vehicle interior. The mounting structure of the vehicle-mounted preview sensor according to claim 1, wherein the mounting structure is formed. 3. A stereo camera comprising a pair of cameras, wherein one of the cameras is installed at a front end of one of the roof rails on a vehicle front side, and the preview sensor is a stereo camera. 3. The mounting structure of the vehicle-mounted preview sensor according to claim 1, wherein the other is installed at a front end of the other roof rail on the vehicle front side. 4. 4. An apparatus for adjusting the displacement of an in-vehicle preview sensor for obtaining a captured image by capturing an image of a situation in front of a vehicle, wherein the device is attached to the front end portions of left and right vehicle bodies in front of the vehicle and is located within the field of view of the preview sensor. A pair of light-emitting sources attached to the camera, based on a captured image obtained by capturing an image of a state in which the light-emitting source pair emits light, to detect a shift in the mounting position of the preview sensor, and to reduce the detected shift. An apparatus for adjusting the displacement of a vehicle-mounted preview sensor, comprising: image processing means for performing image conversion processing on a captured image. 5. The apparatus according to claim 4, wherein the light emitting source is an infrared light emitter. 6. The apparatus according to claim 4, wherein the light emitting source pair is a pair of fender markers attached to the front of the vehicle body. 7. An image processing apparatus, further comprising: an ornament attached to a front center portion of the vehicle body and having a light emitting source, wherein the image processing means is configured to execute the preview based on a captured image of a state in which the ornament emits light. 7. The apparatus according to claim 6, wherein the apparatus detects a displacement of a mounting position of the sensor. 8. The apparatus according to claim 4, wherein said preview sensor is a stereo camera comprising a pair of cameras.