JP2023171709A - In-vehicle camera system and obstacle detection method - Google Patents

Abstract

To reduce the cost of development, installation, and maintenance while providing a good reduction in the detection of obstacles in the blind spot space immediately in front of a vehicle using front sensing cameras installed in a driver's cab.SOLUTION: An in-vehicle camera system includes an imaging unit that captures images of the front of a vehicle from a driver's cab of the vehicle, and a line laser irradiation unit that irradiates the road surface distal to a blind spot space with a line laser through the blind spot space immediately in front of the vehicle at the imaging unit.SELECTED DRAWING: Figure 2

Description

The present technology relates to an in-vehicle camera system and an obstacle detection method.

Front sensing cameras that are currently in practical use have a superior visibility, and are typically installed between the rearview mirror and the windshield inside the vehicle, where the wipers can wipe off rain, snow, and dirt. There is. However, from this installation location, the bonnet falls within the camera's field of view, creating a blind spot directly in front of the vehicle. A similar blind spot occurs from the perspective of the driver inside the car.

Therefore, in the past, in addition to the front sensing camera, there have been known technologies such as installing a camera in a place where the blind spot can be imaged, such as the front bumper, or using millimeter wave radar to detect the presence or absence of obstacles in the blind spot. (Patent Document 1, etc.). However, since these cameras and millimeter-wave radars are attached externally to the vehicle, they lack environmental resistance, and monitoring accuracy may deteriorate due to scratches or dirt, so equipment management is essential. Furthermore, the development and introduction of a detection system using millimeter wave radar requires significant costs.

Further, mounting a radar module in a vehicle is known from Patent Document 2 and the like. This makes it possible to reduce maintenance management problems related to scratches and dirt. However, it is necessary to provide a mechanism on the exterior of the vehicle to allow the reflected waves to enter the interior of the vehicle, and there are problems such as the need to change the design of the vehicle exterior. Additionally, radar diffraction may cause failure to detect thin obstacles such as poles.

Furthermore, a blind spot identification system using infrared rays is known (Patent Document 3, etc.). However, in this case, a new device that receives infrared rays is required. In addition, during the daytime, the infrared rays used to detect obstacles are buried in the strong infrared rays contained in sunlight, resulting in a reduction in detection accuracy.

Japanese Patent Application Publication No. 2005-175603 Japanese Patent Application Publication No. 2006-29916 Special table number 2003-532959

As described above, since the front sensing camera installed inside the vehicle has a blind spot immediately in front of the vehicle, a mechanism is required to detect obstacles that exist in this blind spot. However, the above-mentioned known detection systems have problems in terms of development, introduction, and maintenance costs, and variations in obstacle detection accuracy.
This technology is an in-vehicle camera system and system that can successfully reduce the detection of obstacles in the blind spot in front of the vehicle by the front sensing camera installed in the driver's cabin, and can also keep development, implementation, and maintenance costs low. The purpose of this invention is to provide an obstacle detection method.

In order to achieve the above object, an in-vehicle camera system according to an embodiment of the present disclosure includes:
an imaging unit that captures an image of the front of the vehicle from the driver's cab of the vehicle;
and a line laser irradiation unit that irradiates a line laser onto a road surface distal to the blind spot space through the blind spot space immediately in front of the vehicle of the imaging unit.

The line laser irradiation section is configured to form a continuous line laser marker on the road surface in a direction intersecting an optical axis direction of the imaging section.

The in-vehicle camera system includes:
The vehicle further includes a control unit that controls the line laser irradiation unit to emit the line laser when the vehicle transitions from a stopped state or a parked state to a start preparation state or a start preparation state.

The control unit may be configured to determine the presence or absence of an obstacle within the blind spot area based on an image captured by the imaging unit.

The control unit may be configured to instruct activation of an emergency brake when determining the presence of the obstacle.

The line laser irradiation unit may be configured to irradiate the line laser from a position lower than the bottom of the vehicle body at the front end of the vehicle.

The blind spot space is a field of view of the imaging unit that is blocked by the hood of the vehicle.

The line laser is red.

An obstacle detection method according to another embodiment of the present disclosure includes:
An image of the front of the vehicle is taken from the driver's cab of the vehicle,
irradiating a road surface distal to a blind spot space of the imaging unit immediately in front of the vehicle with a line laser;
When the vehicle transitions from a stopped state or a parked state to a start preparation state or a start preparation state, irradiating the line laser from the line laser irradiation unit,
The presence or absence of an obstacle within the blind spot area is determined based on the captured image.

FIG. 1 is a block diagram showing the configuration of a vehicle-mounted camera system according to a first embodiment of the present technology. FIG. 3 is a diagram showing a blind spot space of the front sensing camera 10 and an optical path of a line laser. FIG. 7 is a plan view showing line laser marks 35 and 36 formed on the road surface distal to the blind spot space DS when no obstacle exists in the blind spot space DS in front of the vehicle. 3 is a diagram showing an example of an image taken by a front sensing camera 10. FIG. FIG. 7 is a plan view showing a pattern of line laser marks 35 and 36 formed on a road surface distal to the blind spot space DS when an obstacle B exists in the blind spot space DS. 7 is a diagram showing another example of an image taken by the front sensing camera 10. FIG. FIG. 3 is a diagram showing the flow of operations from the time of starting the vehicle M to the activation of the automatic emergency brake when an obstacle B exists in the blind spot space DS. 7 is a diagram showing a modification of the line laser marker 39. FIG. 7 is a diagram showing another modification of the line laser marker 39. FIG.

[overview]
The in-vehicle camera system 1 of this embodiment includes:
a front sensing camera 10 that images the front of the vehicle from the driver's cabin of the vehicle;
and a line laser irradiation unit 20 that irradiates a line laser from a position lower than the viewpoint of the front sensing camera 10 through the blind spot space near the front of the vehicle to the road surface on the distal side of the blind spot space. be.

Embodiments of the present technology will be described below with reference to the drawings.
<First embodiment>
FIG. 1 is a block diagram showing the configuration of a vehicle-mounted camera system according to a first embodiment of the present technology.
The vehicle camera system 1 of this embodiment includes a front sensing camera 10, a line laser irradiation unit 20, a control module 30, a vehicle control ECU 40, and a brake system 50.

The front sensing camera 10 is a camera that images the front from inside the driver's cabin of the vehicle, and includes an imager section 11, a camera control section 12, and an IF section 13. The imager unit 11 captures an image using an image sensor such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge Coupled Device) image sensor, and generates image data. The IF unit 13 transmits and receives control commands and image data between the front sensing camera 10 and the control module 30. The camera control unit 12 controls the front sensing camera 10 and controls the line laser irradiation unit 20 to turn on/off.

The line laser irradiation unit 20 is a unit that irradiates a line laser 23 from a position lower than the viewpoint of the front sensing camera 10, passing through a blind spot space near the front of the vehicle of the front sensing camera 10, and irradiating a road surface distal to the blind spot space. It is. The line laser irradiation unit 20 has one or more line laser irradiation devices 21 and 22.

The control module 30 is a controller that performs control for driving support of the vehicle. The control module 30 includes an IF section 31 , a recognition section 32 , a control section 33 , and a CAN (Controller Area Network) communication section 34 .

The IF section 31 is an interface section for communication with the front sensing camera 10. The IF section 31 receives image data transmitted by the IF section 13 of the front sensing camera 10 and supplies it to the recognition section 32 . Further, the IF section 31 sends and receives various commands between the control module 30 and the front sensing camera 10. The recognition unit 32 recognizes the presence or absence of an obstacle in the blind spot based on image data transmitted from the front sensing camera 10 through the IF unit 31. The control unit 33 generates a command for switching on/off of line laser irradiation based on information indicating the state of the vehicle notified from the vehicle control ECU 40, and supplies the command to the front sensing camera 10 through the IF unit 31. Further, the control unit 33 instructs the vehicle control ECU 40 to apply the emergency brake via the CAN communication unit 34 based on the recognition result of the presence or absence of an obstacle obtained by the recognition unit 32. The CAN communication section 34 is a unit that processes communication between the control module 30 and the vehicle control ECU 40.

The vehicle control ECU 40 is a controller that controls various parts of the vehicle, such as the brake system 50, based on vehicle control information supplied from the control module 30.

[Blind spot space and arrangement of front sensing camera 10]
FIG. 2 is a diagram showing the blind spot space of the front sensing camera 10 and the optical path of the line laser. As shown in the figure, the front sensing camera 10 is installed, for example, on the ceiling of the vehicle M or near the rearview mirror so as to be able to image the front of the vehicle M from a viewpoint close to the driver's viewpoint Vp. Here, since the vertical field of view of the front sensing camera 10 is limited by the hood of the vehicle M, a blind spot space DS is created near the front of the vehicle M. Therefore, even if the obstacle B exists in the blind spot space DS, the control module 30 cannot recognize the existence of the obstacle B. Further, since the driver's viewpoint Vp is also close to the viewpoint of the front sensing camera 10, the driver often cannot visually recognize the obstacle B.

The in-vehicle camera system 1 of this embodiment passes through the blind spot space DS near the front of the vehicle of the front sensing camera 10 from a position lower than the viewpoint of the front sensing camera 10, and captures the road surface RF on the distal side of the blind spot space DS. A line laser irradiation unit 20 that irradiates a line laser 23 is provided.
The line laser irradiation unit 20 is configured to form a continuous line laser marker in a direction intersecting the optical axis direction of the front sensing camera 10.
When an obstacle B exists in the blind spot space DS of the front sensing camera 10, the line laser 23 will mark the road surface at a line laser mark formed by irradiating the road surface RF on the distal side from the blind spot space DS. Partial loss occurs because the signal is blocked by obstacle B before reaching RF. Based on the line laser mark having the missing portion, the presence or absence of the obstacle B in the blind spot space DS can be recognized.

The line laser irradiation unit 20 is located at a position where the line laser 23 can pass through the blind spot space DS of the front sensing camera 10 and irradiate the road surface RF on the distal side of the blind spot space DS, such as the lower end of the front bumper. provided. Of course, the line laser irradiation unit 20 is not limited to the lower end of the front bumper, but may be provided at the front bumper, near the front license plate, near the headlights, or at the radiator grille.

FIG. 3 is a plan view showing line laser marks 35 and 36 formed on the road surface distal to the blind spot space DS when no obstacle exists in the blind spot space DS in front of the vehicle.
As shown in the figure, the line laser irradiation unit 20 of this example is composed of two line laser irradiation devices 21 and 22 arranged on the left and right at two locations spaced apart from each other in the vehicle width direction. Reference numeral 35 indicates a line laser mark caused by the line laser 21a emitted from the line laser irradiation device 21 on the left side, and numeral 36 indicates a line laser mark caused by the line laser 22a emitted from the line laser irradiation device 22 on the right side. In this example, when there is no obstacle in the blind spot space DS, the line laser marks 35 and 36 formed by the two line lasers 21a and 21b are, for example, an X font on the road surface distal to the blind spot space DS. Intersect as if drawing. Note that the dotted line 33 is the boundary line on the distal side of the blind spot space DS. At this time, the image taken by the front sensing camera 10 is as shown in FIG. Here, 37 is the front end portion of the front bumper of the vehicle M, which is a factor that creates the blind spot space DS.

Next, a case where an obstacle B exists in the blind spot space DS in front of the vehicle will be described.
FIG. 5 is a plan view showing a pattern of line laser marks 35 and 36 formed on the road surface distal to the blind spot space DS when an obstacle B exists in the blind spot space DS.
In this case, the line lasers 21a and 22a emitted from the line laser irradiation devices 21 and 22 are respectively blocked by the obstacle B in a part of the irradiation angle range depending on the position of the obstacle B in the blind space DS. Therefore, missing portions 35a and 36a occur in at least one of the two line laser marks 35 and 36 formed on the road surface. At this time, the image taken by the front sensing camera 10 is as shown in FIG. Thereby, the recognition unit 32 of the control unit 30 can recognize the presence or absence of the obstacle B in the blind spot space DS based on the pattern of the line laser marks 35 and 36 included in the image data obtained by the front sensing camera 10. Furthermore, since the road surface on the distal side of the blind spot space including the line laser marks 35 and 36 can be visually observed from the driver's viewpoint, it is possible to recognize the presence or absence of an obstacle in the blind spot space DS.

[Example of operation of vehicle camera system 1]
Next, with reference to FIG. 7, the operation of the vehicle-mounted camera system 1 of this embodiment from the time of starting the vehicle M to the activation of the automatic emergency brake when an obstacle B exists in the blind spot space DS will be described.

When the brake is released by the driver (step S1), the control module 30 issues departure or start preparation information to the front sensing camera 10 (step S2). The camera control unit 12 in the front sensing camera 10 receives the departure or start preparation information, starts imaging the front of the vehicle by the imager unit 11, and supplies a line laser irradiation command to the line laser irradiation unit 20 (step S3). Note that the imaging of the front of the vehicle by the front sensing camera 10 may be performed before the brake is released. In this case, the control unit of the front sensing camera 10 only needs to issue a line laser irradiation command when receiving departure or start preparation information.

When the line laser irradiation unit 20 receives a line laser irradiation command from the camera control unit 12 of the front sensing camera 10, it starts irradiation with the line laser (step S4). The recognition unit 32 in the control module 30 recognizes the presence or absence of an obstacle in the blind spot space DS based on the image data including the line laser mark obtained by the front sensing camera 10 after the start of line laser irradiation, and displays the result. The control unit 33 in the control module 30 is notified (step S5). When the control unit 33 in the control module 30 receives the notification that an obstacle exists in the blind spot space DS, it issues an emergency brake activation command to the vehicle control ECU 40 via the CAN communication unit 34 (step S6). When the vehicle control ECU 40 receives the command to apply the emergency brake, it controls the brake system 50 of the vehicle to apply the emergency brake (step S7).
Thereby, if an obstacle exists in the blind spot space DS in front of the vehicle, the vehicle can be restrained from starting by using the brakes, and a collision with the obstacle can be avoided.

[About line laser beam angle and height position]
Next, the irradiation angle β of the line laser will be explained with reference to FIG.
The position P1 of the nearest road surface RF visible from the front sensing camera 10 is determined by the height position of the viewpoint of the front sensing camera 10 and the position P0 of the tip of the hood of the vehicle M. If P2 is the point where the perpendicular from the front end of the vehicle M intersects with the road surface RF, then the triangle formed by the three points P0, P1, and P2 corresponds to the blind spot space D projected on the vertical plane. When the obstacle B does not exist in the blind spot space DS, the line laser 21a (22a) from the line laser irradiation unit 20 needs to be irradiated to the road surface RF on the distal side of the blind spot space DS through the blind spot space DS. That is, if the distance d from point P1 to the irradiation point P4 of the line laser 21a (22a) on the road surface RF is greater than 0, the line laser marks 35 and 36 reflecting the position of the obstacle B in the blind spot space DS will be on the road surface RF. is formed.

In addition, the height h1 of the laser irradiation point of the line laser irradiation unit 20 from the road surface RF is such that h1<H when the height of the obstacle B to be detected is greater than or equal to the height H of the bottom of the vehicle M. When satisfied, the obstacle B in the blind spot space DS can be detected.
And the vertical illumination angle β of the line laser 21a (22a) is
tan(β)=h1/(d+L)
β=arctan(h1/(d+L))
By determining the values of d and h1 within a range that satisfies d>0 and h1<H, a value of β that allows the obstacle B in the blind spot space DS to be detected can be obtained.

[Modified example of line laser irradiation unit 20]
The line laser irradiation unit 20 may be constituted by one line laser irradiation device.
When one line laser irradiation device 23 is used as the line laser irradiation unit 20, it is possible to employ, for example, a chevron-shaped line laser marker 38 as shown in FIG. 8. Alternatively, as shown in FIG. 9, it is also possible to employ a hill-shaped line laser marker 39 in which the top of the above-mentioned mountain-shaped line laser marker 38 is flattened.

Red is the most effective color for line lasers. The reason for this is that the color filter of the imager of the front sensing camera 10 is mainly an RCCC arrangement, and also that the line laser marker and the tail light (red) and front light (white) of the vehicle reflected in the front sensing camera 10 ) has excellent discrimination performance based on the intensity of red light. Depends on things etc.

[Another configuration of this technology]
The present technology can also adopt the following configuration.
(1) An imaging unit that captures an image of the front of the vehicle from the driver's cab of the vehicle;
and a line laser irradiation unit that irradiates a line laser onto a road surface distal to the blind spot space through the blind spot space in front of the vehicle of the imaging unit.
(2) The in-vehicle camera system according to (1) above,
The in-vehicle camera system wherein the line laser irradiation unit is configured to form a continuous line laser marker on the road surface in a direction intersecting the optical axis direction of the imaging unit.
(3) The in-vehicle camera system according to (1) or (2) above,
An in-vehicle camera system further comprising: a control unit configured to cause the line laser irradiation unit to emit the line laser when the vehicle transitions from a stopped state or a parked state to a start preparation state or a start preparation state.
(4) The in-vehicle camera system according to (3) above,
The control unit is configured to determine the presence or absence of an obstacle within the blind spot area based on the image captured by the imaging unit.
(5) The in-vehicle camera system according to (4) above,
The in-vehicle camera system is configured such that the control unit instructs activation of an emergency brake of the vehicle when determining the presence of the obstacle.
(6) An in-vehicle camera system according to any one of (1) to (5) above,
The line laser irradiation unit is configured to irradiate the line laser from a position lower than the bottom of the vehicle body at the front end of the vehicle.
(7) An in-vehicle camera system according to any one of (1) to (6) above,
The blind spot space is a field of view of the imaging unit that is blocked by the hood of the vehicle. In-vehicle camera system.
(8) An in-vehicle camera system according to any one of (1) to (7) above,
An in-vehicle camera system in which the line laser is red.

(9) Image the front of the vehicle from the driver's cab of the vehicle,
irradiating a road surface distal to a blind spot space of the imaging unit immediately in front of the vehicle with a line laser;
When the vehicle transitions from a stopped state or a parked state to a start preparation state or a start preparation state, irradiation of the line laser is turned on,
An obstacle detection method that determines the presence or absence of an obstacle within the blind spot area based on the captured image.
(10) The obstacle detection method according to (9) above,
The obstacle detection method, wherein the line laser irradiation unit forms a continuous line laser marker on the road surface in a direction intersecting an optical axis direction of the imaging unit.
(11) The obstacle detection method according to (9) or (10) above,
An obstacle detection method comprising: controlling the line laser irradiation unit to emit the line laser when the vehicle transitions from a stopped state or a parked state to a start preparation state or a start preparation state.
(12) The obstacle detection method according to (11) above,
The said control part determines the presence or absence of an obstacle in the said blind spot area|region based on the image imaged by the said imaging part.
(13) The obstacle detection method according to (12) above,
An obstacle detection method, wherein the control unit activates an emergency brake of the vehicle when determining the presence of the obstacle.
(14) The obstacle detection method according to any one of (9) to (13) above,
An obstacle detection method comprising irradiating the line laser from a position lower than the bottom of the vehicle body at the front end of the vehicle.
(15) The obstacle detection method according to any one of (9) to (14) above,
The blind spot space is a field of view of the imaging unit that is blocked by a hood of the vehicle.
(16) The obstacle detection method according to any one of (9) to (15) above,
An obstacle detection method in which the line laser is red.

1... Vehicle camera system 10... Front sensing camera 11... Imager section 12... Camera control section 20... Line laser irradiation section 30... Control module 31... IF section 32... Recognition section 33... Control section 40... Vehicle control ECU
50...Brake system

Claims (9)

an imaging unit that captures an image of the front of the vehicle from the driver's cab of the vehicle;
and a line laser irradiation unit that irradiates a line laser onto a road surface distal to the blind spot space through the blind spot space in front of the vehicle of the imaging unit. The in-vehicle camera system according to claim 1,
The in-vehicle camera system wherein the line laser irradiation unit is configured to form a continuous line laser marker on the road surface in a direction intersecting the optical axis direction of the imaging unit. The in-vehicle camera system according to claim 2,
An in-vehicle camera system further comprising: a control unit configured to cause the line laser irradiation unit to emit the line laser when the vehicle transitions from a stopped state or a parked state to a start preparation state or a start preparation state. The in-vehicle camera system according to claim 3,
The control unit is configured to determine the presence or absence of an obstacle within the blind spot area based on the image captured by the imaging unit. The in-vehicle camera system according to claim 4,
The in-vehicle camera system is configured such that the control unit instructs activation of an emergency brake of the vehicle when determining the presence of the obstacle. The in-vehicle camera system according to claim 1,
The line laser irradiation unit is configured to irradiate the line laser from a position lower than the bottom of the vehicle body at the front end of the vehicle. The in-vehicle camera system according to claim 1,
The blind spot space is a field of view of the imaging unit that is blocked by the hood of the vehicle. In-vehicle camera system. The in-vehicle camera system according to claim 1,
An in-vehicle camera system in which the line laser is red. An image of the front of the vehicle is taken from the driver's cab of the vehicle,
irradiating a road surface distal to a blind spot space of the imaging unit immediately in front of the vehicle with a line laser;
When the vehicle transitions from a stopped state or a parked state to a start preparation state or a start preparation state, irradiation of the line laser is turned on,
An obstacle detection method that determines the presence or absence of an obstacle within the blind spot area based on the captured image.

Images