JP2020027031A - On-vehicle distance measuring system, distance measuring method, vehicle lighting fixture and automobile - Google Patents

Abstract

To provide an inexpensive distance measuring system.SOLUTION: An infrared illumination 310 irradiates a road surface with infrared line light L1, in which a distance from its own vehicle is known, or a pattern PTN including spot light. A camera 320 images in a mode including the pattern PTN. An arithmetic logical unit 330 acquires a distance to a target object on the basis of the target object and the pattern PTN included in an image of the camera 320.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a ranging technology for an automobile.

  The distance to the target is extremely important information for automatic driving. As a means for measuring the distance, a stereo camera, LiDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging), a millimeter wave radar, an ultrasonic sonar, or the like is employed.

  LiDAR is promising as a sensor for automatic driving because it can measure the distance to the target and can determine the type of the target by arithmetic processing. However, LiDAR has a large size and a high cost, and therefore has a high threshold for being mounted on an inexpensive vehicle.

  The present invention has been made in view of such circumstances, and one of exemplary purposes of one embodiment thereof is to provide an inexpensive distance measuring system.

  According to one aspect of the present invention, there is provided a method and apparatus for ranging in an automobile. In this method / apparatus, the road surface is irradiated with a pattern including infrared line light or spot light whose distance from the host vehicle is known. Then, the surroundings of the vehicle are imaged by the camera in an aspect including the pattern. Then, the distance to the target is acquired based on the target and the pattern included in the image of the camera.

  Note that any combination of the above-described components, and any conversion of the expression of the present invention among methods, apparatuses, systems, and the like, are also effective as embodiments of the present invention.

  According to the present invention, an inexpensive distance measuring system can be provided.

FIG. 1 is a diagram showing a distance measuring system according to an embodiment. FIG. 2 is a diagram illustrating an operation of the distance measuring system in FIG. 1. FIG. 2 is a diagram illustrating an automobile according to the first embodiment. It is a figure showing the car concerning a 2nd example. It is a figure showing the car concerning a 3rd example. It is a figure showing the car concerning a 4th example. It is a figure showing a headlamp incorporating a distance measuring system.

(Outline of Embodiment)
One embodiment disclosed herein relates to an in-vehicle ranging system. The in-vehicle ranging system includes an infrared light, a camera, and a calculation unit. Infrared illumination illuminates a road surface with an infrared pattern. The pattern includes line light or spot light whose distance from the own vehicle is known. In automobiles, the intensity and color of light that can be radiated for each part and direction are defined by regulations. However, since the pattern is infrared, it is invisible to human eyes and does not violate regulations. The calculation unit receives the image of the camera and acquires the distance to the target based on the target and the pattern included in the image.

  According to this embodiment, the distance to the target can be acquired using the pattern as a ruler. For example, when focusing on one line light (or a set of spot lights) included in the pattern, if the line light is not distorted, the target is located on the back side of the line light, and if distorted, the target is It can be seen that the target is located before the line light. Since the pattern is infrared, it is not affected by the surrounding brightness, so that the distance can be measured day and night.

  In many cases, cameras for monitoring the surroundings of vehicles are already mounted on vehicles. In such a case, the existing hardware can be used for the camera and the arithmetic unit, and the distance measurement function can be added to the conventional system by newly adding infrared illumination.

  Preferably, the pattern may include a plurality of parallel lines. The distance between the plurality of lines may be equal, or the distance may be wider as the distance from the host vehicle increases.

  The pattern may be illuminated concentrically around the camera. Thereby, the distance from the camera can be measured.

  The pattern may include a plurality of lines each extending in a direction along the outer edge when the vehicle is viewed from above and vertically spaced from the outer edge. Thereby, the distance from the outer edge of the vehicle can be measured.

(Embodiment)
The above is the outline of the vehicular lamp. Hereinafter, the present invention will be described based on preferred embodiments with reference to the drawings. The embodiments are illustrative and do not limit the invention, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention. The same or equivalent components, members, and processes shown in the drawings are denoted by the same reference numerals, and the repeated description will be omitted as appropriate. Further, the scale and shape of each part shown in each drawing are set for the sake of convenience in order to facilitate the description, and are not to be construed as limiting unless otherwise noted. In addition, when terms such as “first” and “second” are used in the present specification or claims, the terms do not indicate any order or importance, and certain configurations may be different from other configurations. It is for distinguishing.

  FIG. 1 is a diagram showing a distance measuring system 300 according to the embodiment. The ranging system 300 is mounted on the vehicle 100. The distance measuring system 300 includes an infrared light 310, a camera 320, and a calculation unit 330. The infrared lighting 310 irradiates a road surface with a pattern PTN including infrared line light or spot light whose distance from the own vehicle is known.

  The camera 320 has sensitivity not only to the visible light region but also to the wavelength of the infrared illumination 310, and thus can simultaneously photograph the pattern PTN and the surrounding target OBJ. The image IMG generated by the camera 320 is input to the calculation unit 330.

  The calculation unit 330 acquires the distance (that is, the position) to the target OBJ based on the target OBJ and the pattern PTN included in the image IMG of the camera 320. Arithmetic unit 330 may be a microcontroller that includes a CPU and a memory and can be controlled by software. Alternatively, the arithmetic unit 330 may be hardware such as an FPGA (Field Programmable Gate Array) or an IC (Integrated Circuit) specially designed.

  In this example, the pattern PTN includes a plurality (n) of line lights L1 to Ln, and each of the line lights L1 to Ln is in a direction along an outer edge (front edge in this case) E1 when the vehicle is viewed from above (here, a front edge). It extends in the y direction in the figure). The plurality of line lights are equally spaced apart from the outer edge in a direction perpendicular to the outer edge (x direction in the figure). Each line light may be a set of a plurality of spot lights discretely arranged in a line.

  The above is the basic configuration of the distance measuring system 300. Subsequently, the operation will be described. FIG. 2 is a diagram for explaining the operation of the distance measuring system 300 in FIG. FIG. 2 shows an image IMG of the camera.

  The image IMG includes a pattern PTN including a plurality of line lights L1 to Ln and a target OBJ. When focusing on one line light Li, if the line light Li is not distorted, the target OBJ is located on the back side of the line light Li. It is understood that it is located in. In the example of FIG. 2, the line lights L1 and L2 are drawn on the road surface without distortion, but the line light L3 is partially distorted because it is blocked by the target OBJ. That is, it can be seen that the target OBJ is located between the line lights L2 and L3. The position (distance from the host vehicle) where each line light L1 to Ln is drawn on the road surface is uniquely determined by the optical system of the infrared illumination 310 and is known. Therefore, the calculation unit 330 can acquire the distance (position) to the target OBJ. The calculation unit 330 may identify the type of the target (pedestrian, preceding vehicle, oncoming vehicle, etc.) from the image IMG.

  Although the use of the distance obtained by the distance measuring system 300 is not particularly limited, it can be used, for example, for automatic driving.

  The above is the operation of the distance measurement system 300. Of the infrared light 310, the camera 320, and the computing unit 330, which are components of the distance measuring system 300, the camera 320 and the computing unit 330 are hardware already mounted on many automobiles and are inexpensive. Also, the infrared illumination 310 can be configured at a lower cost than LiDAR.

  Since the distance measuring system 300 uses an infrared pattern, it has an advantage that it is not affected by the brightness of the surroundings, and therefore can measure distance regardless of day or night. In addition, since infrared light is invisible and does not belong to any of red light and white light, there is an advantage that the irradiation direction is not legally restricted.

  The present invention extends to various apparatuses and methods derived from FIG. 1 or the above description, and is not limited to a specific configuration. Hereinafter, more specific configuration examples and embodiments will be described, not to narrow the scope of the present invention but to help understand the essence and operation of the present invention and to clarify them.

(First embodiment)
In the example of FIG. 1, the infrared light is used for distance measurement in front of the vehicle, but the infrared light is not restricted by the irradiation direction. Therefore, the distance measurement system 300 can be used not only for the front of the vehicle but also for the distance measurement on the side of the vehicle or behind the vehicle.

  FIG. 3 is a diagram illustrating an automobile 100A according to the first embodiment. The automobile 100A includes four distance measurement systems 300F, 300B, 300L, and 300R provided on the front, rear, left, and right sides of the vehicle, respectively.

In a first embodiment, the distance measuring system 300 # (# = F, B , L, R) pattern PTN_ # that generates, includes a plurality of lines _{L # 1~L} # n. The line generated by the distance measurement system 300F (300B) extends in the direction (y direction) along the front edge E1 (rear edge E2) when the vehicle is viewed from above. The line generated by the ranging system 300L (300R) extends in a direction (x direction) along the left edge E3 (right edge E4) when the vehicle is viewed from above. Between the distance from the outer edge are equal line _{L F _i, L B _i,} L L _i, L R _i may be continuously formed to surround the vehicle.

(Second embodiment)
FIG. 4 is a diagram illustrating an automobile 100B according to the second embodiment. In the second embodiment, four distance measurement systems 300FL, 300FR, 300RL, and 300RR are provided at four corners of the automobile 100. Each ranging system 300 # (# = FL, FR, RL, RR) forms a pattern PTN_ #.

  At four corners where the four distance measurement systems 300 are provided, left and right head lamps 110L and 110R and left and right rear lamps 140L and 140R are provided. Therefore, at least one of the infrared illumination 310, the camera 320, and the calculation unit 330 among the components of the distance measurement system 300 can be incorporated in the lamps 110 and 140.

  Since the headlamp 110 and the rear lamp 140 include a circuit for turning on various light sources, an optical system, and an arithmetic processing unit, by incorporating the components of the distance measuring system 300 into the lamp, hardware resources can be reduced. Some can be shared, and costs can be reduced.

(Third embodiment)
FIG. 5 is a diagram illustrating an automobile 100C according to the third embodiment. The automobile 100C includes four distance measurement systems 300F, 300B, 300L, and 300R provided on the front, rear, left, and right sides of the vehicle, respectively.

  In the third embodiment, the shape of the pattern PTN generated by the infrared illumination 310 is different from those of the first and second embodiments, and the pattern is radiated concentrically with the camera 320 as the center. As shown in FIG. 1, the camera 320 is arranged close to the infrared illumination 310.

(Fourth embodiment)
FIG. 6 is a diagram illustrating an automobile 100D according to the fourth embodiment. In the fourth embodiment, as in the second embodiment, four distance measurement systems 300FL, 300FR, 300RL, and 300RR are arranged at four corners of the vehicle. The pattern PTN_ # generated by each ranging system 300 # (# = FL, FR, RL, RR) is the same as that in FIG. Also in FIG. 6, the distance measuring system 300 may be built in the headlamps 110 and 140.

  FIG. 7 is a diagram showing a headlamp 110 having a built-in distance measuring system 300. The headlamp 110 is equipped with an ADB (Adaptive Driving Beam) system, and can adaptively control the light distribution pattern according to the surrounding conditions.

  The headlamp 110 includes an interface circuit 120 connected to the vehicle-side ECU via a bus, can receive information from the vehicle-side ECU, and can transmit the state of the headlamp 110 to the ECU. The light distribution pattern to be formed by the headlamp 110 may be calculated by the vehicle-side ECU, and the interface circuit 120 receives data indicating the light distribution pattern.

  In addition, the interface circuit 120 may receive vehicle information such as a vehicle speed and a steering angle.

  The white light source 112 includes a semiconductor light source such as an LED (light emitting diode) and an LD (laser diode). The lighting circuit 116 controls a drive current supplied to the white light source 112, and controls turning on / off and brightness of the white light source 112. The optical system 114 projects the light emitted from the white light source 112 toward the front of the vehicle.

  For example, the optical system 114 may include a patterning device such as a DMD (Digital Mirror Device). The microcomputer 118 changes the light distribution pattern by controlling the DMD.

  Alternatively, the white light source 112 may include a plurality of LEDs arranged in a matrix in a line. The lighting circuit 116 is configured so that a plurality of LEDs can be individually turned on and off. The microcomputer 118 supplies data for instructing turning on and off of the plurality of LEDs to the lighting circuit 116 in accordance with the light distribution pattern. Good.

  The infrared illumination 310 includes an infrared light source 312, an optical system 314, and a lighting circuit 316. As the infrared light source 312, a semiconductor light source such as an LED (light emitting diode) or an LD (laser diode) can be used. The lighting circuit 316 supplies a current to the infrared light source 312 to cause the infrared light source 312 to emit light. The optical system 314 patterns the infrared output of the infrared light source 312 and projects the pattern PTN on a road surface.

  The calculation unit 330 detects a target ahead of the vehicle based on the image IMG captured by the camera 320 and acquires a distance to the target. The acquired distance may be transmitted to the vehicle-side ECU via the interface circuit 120. The function of the calculation unit 330 may be implemented in the microcomputer 118 included in the headlamp 110. This can reduce costs.

  For example, the lighting circuit 116 and the lighting circuit 316 may share a part of hardware. For example, the lighting circuits 116 and 316 may share a power supply circuit and the like. This can reduce costs.

  Further, the headlamp 110 may itself generate the light distribution pattern based on the image captured by the camera 320. In this case, since the camera for controlling the light distribution pattern and the camera for distance measurement can be shared, the cost can be further reduced.

  The present invention has been described based on the embodiments. This embodiment is an exemplification, and it is understood by those skilled in the art that various modifications can be made to the combination of each component and each processing process, and that such modifications are also within the scope of the present invention. is there. Hereinafter, such modified examples will be described.

(First Modification)
The pattern PTN may include a plurality of spot lights arranged in a matrix.

(Second Modification)
In the embodiment, a plurality of lines are fixedly irradiated, but this is not a limitation. For example, taking FIG. 1 as an example, the line light L1 extending in the y direction may be scanned in the x direction. Scanning can increase the resolution of the distance. Of course, the plurality of line lights L1 to L4 shown in FIG. 1 may be scanned in the x direction.

(Third Modification)
In some embodiments, the distance is measured by the distance measurement system 300 in four directions, that is, the front, rear, left, and right directions of the vehicle. For example, a high-precision LiDAR ranging system may be employed for the front, and the inexpensive ranging system according to the embodiment may be employed for the side (or the rear).

  Although the present invention has been described using specific words and phrases based on the embodiments, the embodiments are merely illustrative of one aspect of the principles and applications of the present invention. Many modifications and changes in arrangement may be made without departing from the spirit of the present invention defined in the scope.

300 Distance measuring system 310 Infrared illumination 312 Infrared light source 314 Optical system 316 Lighting circuit 320 Camera 330 Operation unit 100 Automobile 110 Headlamp 112 White light source 114 Optical system 116 Lighting circuit 118 Microcomputer 120 Interface circuit 140 Rear lamp

Claims (6)

An infrared illumination that irradiates a road surface with a pattern including infrared line light or spot light whose distance from the vehicle is known,
Camera and
An arithmetic unit that acquires a distance to the target based on the target and the pattern included in the image of the camera,
An on-vehicle ranging system comprising:   The in-vehicle ranging system according to claim 1, wherein the pattern is radiated concentrically around the camera.   The in-vehicle ranging system according to claim 1, wherein the pattern includes a plurality of lines each extending in a direction along an outer edge when the vehicle is viewed from above and vertically separated from the outer edge. .   An automobile, comprising the on-vehicle ranging system according to any one of claims 1 to 3.   A vehicular lamp comprising the in-vehicle ranging system according to claim 1. Irradiating a road surface with a pattern including infrared line light or spot light having a known distance from the vehicle,
Imaging with a camera;
Acquiring a distance to the target based on the target and the pattern included in the image of the camera;
A distance measuring method for an automobile, comprising:

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