JP2006350670A - Night driving visibility support system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a night driving visibility support system that can image a subject clearly. <P>SOLUTION: According to deflection angle information from an AFS_ECU 8, the shape of a road ahead of a vehicle is estimated, and the setting position of a display area to be displayed on a display device 7 is changed such that the road in the estimated shape is included in the display area. According to the deflection angle information, the setting position and size of an exposure control use area are also changed such that the exposure control use area includes the illumination range of headlights 9 in an image captured by a camera 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a night driving visibility support device.

Conventionally, a technique for ensuring night vision such as a night vision system has been proposed (see, for example, Patent Document 1). According to the technique described in Patent Document 1, the presence of a pedestrian or the like that cannot be confirmed with visible light can be recognized in advance by displaying an image of an infrared camera that captures the front of the vehicle on a head-up display. .
JP-A-11-263145

  In the above-described night vision system that secures night vision, the imaging range of the camera is such that not only pedestrians existing in the course of the vehicle but also pedestrians who are likely to enter the course of the vehicle can be imaged. It is desirable that the angle be as wide as possible (in other words, wide in the vertical and horizontal directions).

  However, when the imaging range is set to a wide angle, a subject such as a pedestrian is projected on the display in a small size. Therefore, conventionally, a range of a part of the captured image is set as a display area, and an image in the display area is displayed on a display so that the subject is focused and projected. For this reason, for example, when the course of the vehicle is curved forward, or when the slope of the road changes in front of the course of the vehicle, the subject existing in front of the course may not be projected.

  Conventionally, the exposure of the camera sets an area to be used for exposure control on the image captured by the camera, and controls the dark part of the area so that it is projected brightly. The exposure is adjusted to match. However, when the subject is present in the bright part of the area, if the exposure is controlled so that the dark part of the area is also projected brightly, the subject is not exposed and an overexposed image is projected.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a night driving vision support device that can clearly display a subject.

In order to achieve the above object, a night driving vision support device according to claim 1,
An infrared camera that is mounted on a vehicle and captures an image in front of the vehicle;
A part of an image captured by the infrared camera is set as a display area, and a display means for displaying an image in the display area is provided.
Road-related information acquisition means for acquiring road-related information regarding the road ahead of the vehicle;
Based on the road related information acquired by the road related information acquisition means, the display area changing means for changing the set position of the display area in at least one of the vertical and horizontal directions of the image captured by the infrared camera,
The display means displays an image in the display area changed by the display area changing means.

  Thus, the present invention does not fix the display area set for the image captured by the infrared camera, but changes the set position of the display area based on the road-related information regarding the road ahead of the vehicle. As a result, the setting position of the display area is changed according to the road ahead of the vehicle. For example, when the course of the vehicle is curved forward, or when the slope of the road changes ahead of the course of the vehicle. Even in such a case, it is possible to clearly display a subject existing in front of the course.

  According to the night driving visibility support device according to claim 2, the road related information acquisition means includes a white line recognition means for recognizing a white line on the road ahead of the vehicle, a steering angle detection means for detecting a steering angle of the steering of the vehicle, Road data including at least one of irradiation optical axis deflecting means for deflecting the irradiation optical axis of the headlight of the vehicle in at least one of the vertical and horizontal directions of the vehicle, the curvature of the road, and the gradient according to the traveling state of the vehicle. Road-related information is acquired from at least one means of road data storage means for storing. Thereby, the road relevant information regarding the road ahead of the vehicle can be acquired.

The night driving visibility support device according to claim 3,
An infrared camera that is mounted on a vehicle and captures an image in front of the vehicle;
A part of an image captured by the infrared camera is set as a display area, and a display means for displaying an image in the display area is provided.
Pitch angle detecting means for detecting the pitch angle of the vehicle;
Display area changing means for changing the set position of the display area in the vertical direction of the image captured by the infrared camera based on the pitch angle detected by the pitch angle detecting means,
The display means displays an image in the display area changed by the display area changing means.

  For example, when the weight of an occupant seated in the rear seat of the vehicle or a load on the trunk of the rear portion of the vehicle is heavy, the rear portion of the vehicle sinks, and as a result, the pitch angle of the vehicle changes. As described above, when the pitch angle of the vehicle changes, the image captured by the infrared camera is changed in the upward direction of the vehicle, and the subject existing in front of the course may not be projected.

  Therefore, the present invention changes the set position of the display area in the vertical direction based on the pitch angle of the vehicle. Thereby, for example, when the rear part of the vehicle sinks, the setting position of the display area is changed downward in the image captured by the infrared camera, and conversely, when the front part of the vehicle sinks, the display area Can be changed upward in the image captured by the infrared camera. As a result, a subject existing in front of the course can be projected.

  According to the night driving vision support device of the fourth aspect, the display area changing means changes so that the road ahead of the vehicle is included in the display area. Accordingly, for example, even when the vehicle course is curved forward, or when the road gradient changes ahead of the vehicle course, the vehicle course is included in the display area.

The night driving visibility support device according to claim 5,
An infrared camera that is mounted on a vehicle and captures an image in front of the vehicle;
Display means for displaying an image captured by the infrared camera;
Set the exposure control usage area to be used when controlling the exposure of the infrared camera for the image captured by the infrared camera, and perform the exposure control of the infrared camera based on the brightness of the image in the exposure control usage area Control means;
Irradiating optical axis deflecting means for deflecting the irradiating optical axis of the headlight of the vehicle in at least one of the vertical and horizontal directions of the vehicle according to the traveling state of the vehicle,
The exposure control means changes the setting position and / or size of the exposure control usage area in the left-right direction of the image based on the deflection angle of the irradiation optical axis deflected by the irradiation optical axis deflection means. A change means is provided.

  In a vehicle provided with the irradiation optical axis changing means, for example, the irradiation range of the headlight of the vehicle is changed at any time according to traveling conditions such as the traveling direction of the vehicle. The subject is irradiated with light from the headlight.

  Therefore, in the present invention, at least one of the setting position and the size of the exposure control use area is changed based on the deflection angle of the irradiation optical axis deflected by the irradiation optical axis deflecting unit. Thereby, when a subject exists in a bright part of the exposure control use area, exposure control can be performed so that the subject is exposed. As a result, a subject existing in a bright part can be clearly displayed.

  According to the night driving vision support device according to claim 6, the exposure control use area changing means changes the exposure control use area so as to include the irradiation range of the headlight in the image captured by the infrared camera. To do. Thereby, according to the irradiation range of a headlight, an exposure control use area | region can be changed.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram illustrating a configuration of a nighttime driving vision support apparatus according to an embodiment. As shown in FIG. 1, the nighttime driving vision support device uses the camera 1, the control unit 2, the display device 7, and the irradiation optical axis of the headlight 9 of the vehicle according to the traveling state of the vehicle. An AFS_ECU 8, a steering sensor 10, and a pitch angle sensor 11, which are AFS (Adaptive Front-lighting System) control devices that deflect in the vertical direction and the horizontal direction, are provided. The control unit 2, the AFS_ECU 8, the steering sensor 10, and the pitch angle sensor 11 are connected via an in-vehicle LAN, and transmit and receive various types of information through the in-vehicle LAN.

  In addition, the headlamp 9 of this embodiment irradiates light including the wavelength band of visible light as well as the wavelength band of visible light, but separately provides an infrared projector that irradiates infrared light, You may make it irradiate infrared light from the infrared projector forward in the traveling direction of the vehicle.

  The camera 1 is mounted on a vehicle and captures an image in front of the vehicle in the traveling direction. The camera 1 outputs a digital image signal to the control unit 2 and outputs an NTSC analog image signal to the display device 7. The camera 1 includes an imager, a filed programmable gate array (FPGA), or an application specific integrated circuit (ASIC) having sensitivity in both visible light and infrared light wavelength bands. The FPGA (or ASIC) includes functions of an image cutout unit, an amplification unit, and an A / D conversion unit.

  The image cutout unit sets a part of the captured image as a display area based on the cutout position included in the camera control value instructed from the control unit 2, and pixels from each pixel of the imager included in the set display area A value (value corresponding to the intensity of received light) signal is extracted.

  The amplification unit amplifies the pixel value signal extracted by the image cutout unit with a predetermined gain, and the amplified pixel value signal is converted into an NTSC analog image signal, and the converted signal is held. The amplifying unit amplifies the pixel value signal from all the pixels of the imager with a predetermined gain, is converted into a digital image signal by the A / D conversion unit, and the converted signal is held. The FPGA (or ASIC) outputs the held analog image signal to the display device 7 for each line of the image and outputs the digital image signal to the control unit 2 for each line of the image.

  The control unit 2 acquires information on the deflection angle of the irradiation optical axis from the AFS_ECU 8, obtains a cutout position for changing the set position of the display area according to the deflection angle information, and obtains information on the cutout position. The included camera control value is output to the camera 1. The control unit 2 controls the exposure of the camera 1 so that the contrast of the image is appropriate. That is, the control unit 2 outputs camera control values including these adjustment instruction values to the camera 1 in order to adjust the shutter speed and frame rate of the camera 1 and the gain of the amplification unit.

  As illustrated in FIG. 2, the control unit 2 includes an image interface (I / F) 3, a CPU 4, a memory 5, and a communication I / F 6. The image I / F 3 receives position information of each pixel value of the digital image signal output from the camera 1 and transmits the position information to the CPU 4. The CPU 4 recognizes which pixel position the pixel value output for each line of the digital image corresponds to based on the position information transmitted by the image I / F 3. Then, the pixel value output from the camera 1 is stored in the memory 5 so as to correspond to the recognized pixel position. In this way, the digital image signal output from the camera 1 is stored in the memory 5.

  Communication I / F6 adjusts communication between CPU4 and in-vehicle LAN. In the present embodiment, the CPU 4 performs predetermined image processing on the digital image signal, and transmits information subjected to the image processing to the in-vehicle LAN. The display device 7 is, for example, a head-up display (HUD), and receives an analog image signal in the display area and displays an image in the display area on the display.

  The AFS_ECU 8 detects the deflection angle of the irradiation optical axis of the headlamp 9 (vehicle) based on the detection results from the steering sensor 10 that detects the steering angle of the vehicle and the vehicle speed sensor (not shown) that detects the vehicle speed. The angle of the vehicle in the vertical direction and the horizontal direction with respect to the angle when the irradiation optical axis is aligned with the straight traveling direction is calculated, and control is performed so that the irradiation optical axis of the headlamp 9 becomes this deflection angle. . Further, the AFS_ECU 8 outputs information on the deflection angle to the control unit 2.

FIG. 3 is a flowchart showing processing executed in the control unit 2. In FIG. 3, first, in step S110, the digital image signal output from the camera 1 is captured. That is, as described above, each pixel value constituting the digital image signal is stored in the memory 5 so as to correspond to the position information output from the camera 1.

  In step S120, based on the deflection angle information from the AFS_ECU 8, a cut-out position calculation process for obtaining a cut-out position for changing the set position of the display area in the camera 1 is performed. This process will be described with reference to the flowchart shown in FIG. In step S210 shown in FIG. 4, AFS deflection angle information is acquired. In step S220, a cut-out position for changing the display area setting position is calculated based on the deflection angle information. A method for calculating the cutout position will be described below.

  As shown in FIG. 6 (a), in the conventional night driving vision support device, a range of a part of the image captured by the camera 1 with reference to the front and rear axes of the vehicle is set as a display area. Is displayed on the display device 7 so that the subject is focused and projected. For this reason, for example, when the course of the vehicle is curved forward as shown in FIG. 9A, the subject existing in front of the course may not be projected.

  Therefore, in step S220, as shown in FIG. 6A, the display area set for the image captured by the camera 1 is not fixed, but as shown in FIG. Based on the road related information regarding the road, the setting position of the display area is changed in the horizontal direction of the image. Specifically, the shape of the road ahead of the vehicle is estimated based on the deflection angle information from the AFS_ECU 8 as road-related information, and the setting position of the display area is changed so that the road of the estimated shape is included in the display area. The cut-out position for performing is calculated.

  Thereby, since the course of the vehicle is included in the display area, even if the course of the vehicle is curved forward, the display area including the curved course can be set. As a result, as shown in FIG. 6 (b), for example, even when the course of the vehicle is curved forward, a subject existing inside or outside the curve can be clearly displayed on the display device 7. It becomes possible.

  In step S230, the cutout position to be included in the camera control value is changed to the cutout position calculated in step S220. In step S130 shown in FIG. 3, the digital image signal is subjected to predetermined image processing, and the information subjected to the image processing is transmitted to the in-vehicle LAN. In step S140, exposure control of the camera 1 is performed. The camera exposure control process will be described with reference to the flowchart of FIG.

  In FIG. 5, first, in step S310, AFS deflection angle information is acquired. In step S320, in the digital image signal output from the camera 1, the setting position and size of the exposure control use area to be used when calculating the exposure control amount of the camera 1 are changed based on the deflection angle information.

  That is, as shown in FIG. 7 (a), in the conventional night driving vision support device, the exposure of the camera 1 is present in the dark part by controlling the dark part of the exposure control usage area so that it is projected brightly. The exposure is set to match the subject. However, if the subject is present in the bright part of the area, and the exposure is controlled by increasing the gain so that the dark part of the area is projected brightly, the subject will not be exposed and the image will be overexposed. It will be projected.

  That is, in a vehicle equipped with an AFS, the irradiation range of the headlight of the vehicle is changed from time to time in the vertical direction and the horizontal direction depending on the traveling situation such as the traveling direction of the vehicle. A subject such as a headlight is irradiated with light from a headlight. Therefore, when the exposure is adjusted to the dark part, the exposure cannot be adjusted to the subject existing in the bright part.

  Therefore, in step S320, as shown in FIG. 7B, the setting position and size of the exposure control use area are changed in the vertical and horizontal directions of the image according to the light distribution of AFS. Specifically, based on the deflection angle information from the AFS_ECU 8, the size of the exposure control use area is not changed so that the exposure control use area includes the irradiation range of the headlamp 9 in the image captured by the camera 1. The setting position is changed to the vertical direction or the horizontal direction of the image. Alternatively, the size of the exposure control usage area is changed by changing the vertical and / or left and right boundary positions of the exposure control usage area in the vertical direction and the horizontal direction of the image.

  As a result, the exposure control use area is changed in accordance with the irradiation range of the headlamp 9, so that when the subject exists in a bright part of the exposure control use area, exposure control is performed so that the subject is exposed. Can do. As a result, a subject existing in a bright part can be clearly displayed.

  In step S330, the pixel values in the exposure control usage area are averaged to calculate the brightness of the exposure control usage area. In addition, when using a camera that outputs a pixel value that is not simply proportional to the brightness level of the imaging range, the pixel value of each pixel is converted into luminance according to the pixel value characteristics of the camera, and after that, Calculate by averaging the luminance.

  In step S340, if the brightness of the exposure control use area calculated in step S330 is within a certain luminance level range, the exposure control amount is maintained as the current exposure control amount. Then, an exposure control amount to be within the range is calculated.

  In step S350, the camera control value including the cut-out position calculated in S220 and corresponding to the exposure control amount calculated in S340 is output to the camera 1. If the target exposure control amount exceeds the adjustment range of the gain or shutter speed, the camera control value corresponding to the target exposure control amount is generated by changing the frame rate.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the image signal processing in S120 of the present embodiment, the shape of the road ahead of the vehicle is estimated based on the deflection information from the AFS_ECU 8, and the display area setting position is set so that the road having the estimated shape is included in the display area. However, for example, the vehicle is also obtained from the white line recognition result of the white line recognition means for recognizing the white line on the road ahead of the vehicle, the detection result of the steering sensor 10, the road data including the curvature of the road used in the navigation system, and the like. The shape of the road ahead can be estimated. Therefore, information regarding the shape of the road ahead of the vehicle may be acquired from the white line recognition result, the detection result of the steering angle sensor, road data, and the like.

  Further, in this embodiment, the setting position of the display area is changed in the left-right direction. However, when the road gradient changes in front of the vehicle course, the subject existing in front of the course cannot be projected. Sometimes. In such a case, for example, the road gradient in front of the vehicle can be grasped from road data including the road gradient used in the navigation system. Therefore, the display area setting position is changed in the vertical direction according to this gradient. You may make it do.

  Further, for example, when the weight of a passenger seated in the rear seat of the vehicle or the load of the trunk at the rear of the vehicle is heavy, the rear of the vehicle sinks as shown in FIG. The angle changes. Thus, when the pitch angle of the vehicle changes, the image captured by the infrared camera is changed upward in the vehicle as compared with the normal case shown in FIG. As a result, it may not be possible to project a subject existing in front of the course.

  Therefore, for example, the display area setting position may be changed in the vertical direction based on the size of the pitch angle detected by the pitch angle sensor 11 shown in FIG. Thereby, for example, when the rear portion of the vehicle sinks, the setting position of the display area shown in FIG. 9A is changed downward in the image captured by the camera 1 as shown in FIG. 9B. It becomes possible to do.

  If the pitch angle sensor 11 is not provided, for example, in the case of a vehicle to which an air suspension is applied, the pitch angle of the vehicle is calculated from the detection result of the wheel height sensor that detects the stroke amount of the air suspension. What should I do?

  Conversely, when the front part of the vehicle sinks, the set position of the display area can be changed upward in the image captured by the camera 1. As a result, a subject existing in front of the course can be projected.

It is a block diagram which shows the structure of the night driving | operation visual field assistance apparatus in embodiment. 3 is a block diagram showing an internal configuration of a control unit 2. FIG. 4 is a flowchart illustrating image signal processing executed in a control unit 2. It is a flowchart which shows an image signal process. It is a flowchart which shows an exposure control process. (A) is a figure which shows the display area set centering on the front-back axis | shaft of a vehicle, (b) is a figure which shows the display area where a setting position is changed according to a road shape. (A) is a figure which shows the setting position of an exposure control use area | region, (b) is a figure which shows the exposure control use area | region where a setting position and a magnitude | size are changed according to the light distribution of AFS. . (A) is an image figure when the pitch angle of a vehicle does not change, (b) is an image figure when the pitch angle of a vehicle changes. (A), (b) is a figure which shows the setting position of the display area before a change, and the setting position of the display area after a change.

Explanation of symbols

1 Camera 2 Control unit 3 Image I / F
4 CPU
5 Memory 6 Communication I / F
7 Display device 8 AFS_ECU
9 Headlight 10 Steering sensor 11 Pitch angle sensor

Claims (6)

An infrared camera mounted on a vehicle and capturing an image in front of the vehicle;
In a night driving vision support device comprising a display means for displaying a part of an image captured by the infrared camera as a display area and displaying an image in the display area,
Road-related information acquisition means for acquiring road-related information regarding the road ahead of the vehicle;
Display area changing means for changing the set position of the display area in at least one of the vertical and horizontal directions of the image captured by the infrared camera based on the road related information acquired by the road related information acquisition means; Prepared,
The night display visibility support device, wherein the display means displays an image in the display area changed by the display area changing means.   The road related information acquisition means includes a white line recognition means for recognizing a white line on a road ahead of the vehicle, a steering angle detection means for detecting a steering angle of the steering of the vehicle, and a head of the vehicle according to a traveling state of the vehicle. At least one of road data storage means for storing road light data including at least one of irradiation light axis deflection means for deflecting the light irradiation optical axis in at least one of the vertical and horizontal directions of the vehicle and road curvature. The night driving vision support apparatus according to claim 1, wherein the road-related information is acquired from two means. An infrared camera mounted on a vehicle and capturing an image in front of the vehicle;
In a night driving vision support device comprising a display means for displaying a part of an image captured by the infrared camera as a display area and displaying an image in the display area,
Pitch angle detecting means for detecting the pitch angle of the vehicle;
Display area changing means for changing the set position of the display area in the vertical direction of the image captured by the infrared camera based on the pitch angle detected by the pitch angle detecting means,
The night display visibility support device, wherein the display means displays an image in the display area changed by the display area changing means.   The night display visibility support device according to any one of claims 1 to 3, wherein the display area changing unit changes the road ahead of the vehicle to be included in the display area. An infrared camera mounted on a vehicle and capturing an image in front of the vehicle;
Display means for displaying an image captured by the infrared camera;
For the image captured by the infrared camera, an exposure control usage area to be used when controlling the exposure of the infrared camera is set, and the exposure control of the infrared camera is performed based on the brightness of the image in the exposure control usage area Exposure control means for performing,
Irradiating optical axis deflecting means for deflecting the irradiating optical axis of the headlight of the vehicle in at least one of the vertical and horizontal directions of the vehicle according to the traveling state of the vehicle,
The exposure control means changes exposure control use area changing means for changing at least one of the setting position and size of the exposure control use area based on the deflection angle of the irradiation optical axis deflected by the irradiation optical axis deflection means. A night driving visibility support device comprising:   6. The night driving visibility support device according to claim 5, wherein the exposure control use area changing unit changes the exposure control use area so as to include an irradiation range of the headlight in an image captured by the infrared camera. .

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