KR20210153913A - Apparatus for LIDAR - Google Patents

Abstract

The application relates to a lidar device. According to an embodiment of the present invention, the lidar device includes: a laser light source unit for sequentially irradiating a plurality of line lasers into a target space; an image sensor unit which detects each of the line lasers reflected in the target space and individually generates corresponding detection images; and an image processing unit which extracts a laser pattern corresponding to the line laser from the detection image to generate coordinate information in the target space for the laser pattern, and collects the coordinate information generated from each detection image to create a 3D map of space. Accordingly, a 3D map of the target space may be generated by sequentially irradiating the plurality of line lasers.

Description

LIDAR device {Apparatus for LIDAR}

The present application relates to a lidar device for measuring a distance using triangulation, and more particularly, to a lidar device capable of generating a three-dimensional map of a target space by sequentially irradiating a plurality of line lasers will be.

Laser (Light Amplification by the Stimulated Emission of Radiation, LASER) is light amplified by stimulated emission and is used as a core technology in many fields such as electronics, optical communication, medicine, and national defense.

In addition, a LiDAR (Light Detection and Ranging, LiDAR) device uses a laser to measure the distance to an object, and has recently attracted attention as a core technology for autonomous vehicles, mobile robots, and drones.

The conventional LiDAR device applies the TOF (Time of Flight) method that calculates the distance through the flight time of the laser, so it has the advantage of high precision and high resolution measurement, but it is expensive because expensive image sensors must be arranged in an array There are disadvantages such as being expensive and the overall size is large.

An object of the present application is to provide a lidar device capable of generating a three-dimensional map of a target space by sequentially irradiating a plurality of line lasers.

A lidar device according to an embodiment of the present invention includes a laser light source unit for sequentially irradiating a plurality of line lasers into a target space; an image sensor unit that detects the line lasers reflected in the target space, respectively, and individually generates corresponding detection images; and extracting a laser pattern corresponding to the line laser from the detection image to generate coordinate information in the target space for the laser pattern, and collecting the coordinate information generated from each of the detection images in the target space It may include an image processing unit for generating a three-dimensional map of the.

Here, the laser light source unit includes: a laser diode generating laser light of a set wavelength; a diffraction grating unit dividing the laser light into a plurality of line lasers traveling in different optical paths; and a shutter unit for individually opening or closing the light path.

Here, the laser light source unit may further include an auxiliary light source unit for outputting a visible light laser indicating a sensing region to which the line laser is irradiated in the target space.

Here, the diffraction grating unit generates a plurality of parallel line lasers in a horizontal direction, and the plurality of line lasers may be divided so as to proceed in optical paths of different angles in a vertical direction, respectively.

Here, the shutter unit may open any one of the plurality of light paths and close all others, and may sequentially open the plurality of light paths from top to bottom or from bottom to top.

Here, the shutter unit may open or close the optical path by using a liquid crystal shutter.

A 3D map generation method using a lidar device according to an embodiment of the present invention includes the steps of: (a) irradiating any one of N line lasers into a target space; (b) generating a detection image by sensing the line laser reflected in the target space; (c) extracting a laser pattern corresponding to the line laser from the detection image, and generating coordinate information in the target space for the laser pattern; and (d) repeating steps (a) to (c) for N line lasers to generate N pieces of coordinate information, and collecting the N pieces of coordinate information to generate a three-dimensional map of the target space. may include steps.

Incidentally, the means for solving the above problems do not enumerate all the features of the present invention. Various features of the present invention and its advantages and effects may be understood in more detail with reference to the following specific embodiments.

Since the lidar device according to an embodiment of the present invention generates a three-dimensional map of the target space by sequentially irradiating a plurality of line lasers, it is possible to reduce the amount of computation required for image processing and to improve the processing speed. can

According to the lidar device according to an embodiment of the present invention, since a three-dimensional map of the target space can be generated using image processing, manufacturing cost reduction and product size reduction can be achieved compared to the case of using TOF, etc. can be implemented

1 is a block diagram illustrating a lidar device according to an embodiment of the present invention.
2 is a schematic diagram illustrating the detection of an object using a lidar device according to an embodiment of the present invention.
3 to 5 are schematic diagrams showing the operation of the shutter unit of the lidar device according to an embodiment of the present invention.
6 is a schematic diagram showing the operation of the auxiliary light source of the lidar device according to an embodiment of the present invention.
7 is a schematic diagram illustrating coordinate information and a three-dimensional map generated by a lidar device according to an embodiment of the present invention.
6 is a view showing the sensitivity of each wavelength of the first sensor and the second sensor according to an embodiment of the present invention.
8 is a flowchart illustrating a three-dimensional motion generation method using a lido device according to an embodiment of the present invention.

Hereinafter, preferred embodiments will be described in detail so that those of ordinary skill in the art can easily practice the present invention with reference to the accompanying drawings. However, in describing the preferred embodiment of the present invention in detail, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, the same reference numerals are used throughout the drawings for parts having similar functions and functions.

In addition, throughout the specification, when a part is 'connected' with another part, it is not only 'directly connected' but also 'indirectly connected' with another element interposed therebetween. include In addition, 'including' a certain component means that other components may be further included, rather than excluding other components, unless otherwise stated. In addition, terms such as "~ unit" and "module" described in the specification mean a unit that processes at least one function or operation, which may be implemented as hardware or software, or a combination of hardware and software.

1 is a block diagram illustrating a lidar apparatus according to an embodiment of the present invention, and FIG. 2 is a schematic diagram illustrating detection of an object using the lidar apparatus according to an embodiment of the present invention.

1 and 2 , the lidar device 100 may include a laser light source unit 110 , an image sensor unit 120 , and an image processing unit 130 .

Hereinafter, the lidar device 100 according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2 .

The laser light source unit 110 may sequentially irradiate a plurality of line lasers into the target space A. That is, after generating a plurality of line lasers traveling in different optical paths, each of the line lasers may be sequentially irradiated into the target space (A). Here, the target space (A) to which the laser light is irradiated may be a security area such as a house or a store, or a space around a vehicle being driven or parked. However, the present invention is not limited thereto, and any space may correspond to a space in which the lidar device 100 is installed and irradiated with laser light.

Specifically, referring to FIG. 3 , the laser light source unit 110 may further include a laser diode 111 , a diffraction grating unit 112 , and a shutter unit 113 .

The laser diode 111 may generate laser light having a set wavelength, and in this case, the set wavelength may be set to an infrared wavelength region. That is, the infrared laser is irradiated in the target space (A), so that the laser light is not confirmed with the naked eye.

Meanwhile, the laser diode 111 may generate laser light having a dotted cross-section, and then may be processed into a plurality of line lasers by the diffraction grating unit 112 . That is, the laser light generated by the laser diode 111 may be input to the diffraction grating unit 112 , and the diffraction grating unit 112 may divide the laser light into a plurality of line lasers traveling in different optical paths. have.

The diffraction grating unit 112 may process the collimated laser light in various forms, and according to an embodiment, it is also possible to divide the collimated laser light into a plurality of line laser forms. That is, the diffraction grating unit 112 may generate a plurality of line lasers parallel to the horizontal direction, and in this case, the plurality of line lasers may be divided to travel in optical paths of different angles in the vertical direction. According to an embodiment, it is also possible to generate a plurality of line lasers parallel to the vertical direction, and divide the line lasers so as to proceed in optical paths of different angles in the horizontal direction.

The shutter unit 113 may individually open or close the optical path of each line laser. As shown in FIG. 3 , the plurality of line lasers generated by the diffraction grating unit 112 may pass through the shutter unit 113 and output to the target space A. As shown in FIG. At this time, the shutter unit 113 may open or close the optical path of each of the line lasers, and only the line laser selected by the shutter unit 113 may be emitted to the target space (A). That is, the shutter unit 113 may open any one of the plurality of light paths and close all others, thereby controlling the line lasers emitted to the target space A.

In some embodiments, as shown in FIG. 3 , an open portion C may be included in the shutter unit 113 , and the remaining area except for the open portion C may be closed to block the progress of laser light. have. That is, after positioning the open portion C at a specific position within the shutter unit 113 , the line laser L1 incident on the open portion C is transmitted through the line laser L1 to the target space A can be investigated within. In this case, the position of the opening part C may be controlled by the shutter part 113 .

The shutter unit 113 may output a plurality of line lasers one by one into the target space A, for example, may sequentially open a plurality of optical paths from top to bottom or from bottom to top. In this case, the line lasers may be sequentially irradiated from bottom to top or from top to bottom in the target space (A).

That is, as shown in FIG. 3 , the first line laser L1 may be irradiated into the target space A, and then, as shown in FIG. 4 , the second line laser L2 in the target space A. may be irradiated to the lower portion of the first line laser L2. In addition, as shown in FIG. 5 , the third line laser L3 may be irradiated to the lower portion of the second line laser L2 in the target space A. As shown in FIG.

Meanwhile, although a case of sequentially irradiating a single line laser is illustrated in FIGS. 3 to 5 , it is also possible to sequentially irradiate a group of a plurality of line lasers according to an exemplary embodiment. That is, the plurality of line lasers may be classified into a preset group, and the shutter unit 113 may be controlled to be irradiated into the target space A sequentially for each group. In this case, the line lasers included in the same group may be simultaneously output.

Additionally, the laser light source unit 110 according to another embodiment of the present invention may include a position control unit (not shown) for controlling the angle of the laser light source unit 110 instead of the shutter unit 130 . That is, by controlling the angle of the laser light source unit 110 , the position at which the line laser output from the laser light source unit 110 is irradiated in the target space A can be changed. In this case, like the shutter unit 113 , it is possible to sequentially irradiate a plurality of line lasers into the target space A. However, it may be effective to use the shutter unit 113 in consideration of a structure or equipment additionally required for angle control of the laser light source unit 110 .

The shutter unit 113 may open or close the optical path in various ways such as mechanical or electronic, and it is also possible to apply a liquid crystal shutter using a liquid crystal according to an embodiment. For example, the liquid crystal may be solidified by applying a voltage to the entire region of the liquid crystal shutter, and then only the voltage in the region corresponding to a specific optical path may be removed for a predetermined time. In this case, since the liquid crystal is maintained in a liquid state in the region from which the voltage is removed, the line laser may be transmitted through it, thereby controlling whether to output each of the line lasers.

Additionally, as shown in FIG. 6 , the laser light source unit 110 according to an embodiment of the present invention may further include an auxiliary light source unit 114 . That is, the auxiliary light source unit 114 may output a visible light laser in the target space A, and may display the sensing area T to which the line lasers L are irradiated using the visible laser. That is, after the user installs the lidar device 100 , the user may be visually provided with information on an area in which the lidar device 100 actually performs measurement. In particular, the line laser may be implemented as an infrared laser, and in this case, the line laser cannot be visually checked by the user. Accordingly, it is possible to check the sensing region T to which the line lasers are actually irradiated through the visible light laser output from the auxiliary light source unit 114 .

Meanwhile, the auxiliary light source unit 114 includes a visible light diode D1 for generating a visible light laser having a wavelength band of visible light, and an auxiliary diffraction grating D2 for processing the visible light laser into a form capable of displaying the sensing region T. may include As shown in FIG. 5 , the auxiliary diffraction grating D2 may be processed to display the sensing region T by processing the visible light laser in a rectangular shape, but is not limited thereto and may be deformed into various shapes such as a circle or a trapezoid. .

The image sensor unit 120 may individually generate a detection image by sensing the laser beams reflected in the target space A, respectively. Depending on the embodiment, the image sensor unit 120 may be implemented as a CCD (Charge-Coupled Device) sensor or a CMOS (Complementary Metal-Oxide Semiconductor) sensor, etc., and the image sensor unit 120 may be configured as a target space (A). ) can be converted into an electrical signal by measuring the luminance of the reflected laser light. That is, a two-dimensional detection image may be generated by setting the measured luminance value of the laser light as the pixel value of each pixel.

Here, the laser light source unit 110 may sequentially irradiate each of the line lasers one by one, and in this case, the image sensor unit 120 may sequentially generate detection images each including one line laser. That is, the image sensor unit 120 may generate detection images for each of the plurality of line lasers L1 , L2 , and L3 irradiated into one sensing area T .

Depending on the embodiment, it is also possible to include a plurality of line lasers in the detection image at the same time, but in this case, problems such as an increase in the amount of calculation for image processing and a slow processing speed may occur.

On the other hand, here, the shutter unit 130 is introduced, a plurality of line lasers are sequentially irradiated, and then a detection image including an individual line laser is used. It is possible to provide

The image processing unit 130 may extract a laser pattern corresponding to the line laser L from the detection image, and may generate coordinate information in the target space A for the laser pattern.

A laser pattern corresponding to the line laser may be included in the detection image, and the image processing unit 130 may extract pattern pixels representing the laser pattern. Then, by using the separation distance and installation angle of the laser light source unit 110 and the image sensor unit 120, distance information to a point in the actual target space (A) corresponding to each pattern pixel can be extracted. , based on this, it is possible to generate coordinate information of the corresponding point. That is, as shown in FIG. 7( a ), coordinate information for each point where the line laser is irradiated in the actual target space A can be generated from the laser pattern displayed in one detection image.

Here, the image processing unit 130 may receive detection images for each line laser sequentially irradiated in the detection area T from the image sensor unit 120 , and the image processing unit 130 may receive each detection image Coordinate information can be extracted from

Thereafter, the image processing unit 130 may collect the corresponding coordinate information to generate a three-dimensional map of the target space A, as shown in FIG. 7(b) . Here, the image processing unit 130 may know in advance the order in which the laser light source unit 110 irradiates each line laser in the target space, and may generate a three-dimensional map by collecting coordinate information according to the order. For example, the laser light source unit 110 may irradiate a line laser in the target space A sequentially from top to bottom, and the image processing unit 130 extracts coordinate information from each detected image, and then coordinates information They can be combined from top to bottom to create a three-dimensional map.

In some embodiments, the image processing unit 110 may extract height information from the position of each laser pattern, and it is also possible to generate a 3D map by reflecting the height information of each coordinate information.

8 is a flowchart illustrating a 3D map generation method using a lidar device according to an embodiment of the present invention.

Referring to FIG. 8 , the lidar device may first irradiate any one of N line lasers into the target space ( S10 ). The LIDAR device may generate a plurality of line lasers traveling in different optical paths, and may sequentially irradiate the generated line lasers into the target space one by one. The lidar device may include a shutter unit to control output line lasers. According to an embodiment, the order of outputting each of the line lasers may be predetermined.

Thereafter, the lidar device may detect the line laser reflected in the target space and generate a detection image (S20). That is, the lidar device may include a CCD sensor or a CMOS sensor, and may generate a detection image by detecting the reflected line laser using this. Here, the detection image may be generated for each line laser.

The lidar device may extract a laser pattern corresponding to the line laser from the detection image, and may generate coordinate information in a target space for the laser pattern (S30). The lidar device may perform image processing on the detected image to remove noise, and extract a laser pattern through binarization or the like. Then, by using the triangulation method, it is possible to generate coordinate information for the laser pattern displayed in the detection image.

Thereafter, the lidar device may repeat steps S10 to S30 for each of the N line lasers, and may generate N pieces of coordinate information through this. That is, detection images may be generated by sequentially outputting respective line lasers in the target space, and respective coordinate information may be generated from the detection image. The lidar device may collect the generated N pieces of coordinate information, and may generate a three-dimensional map of the target space using this. Here, as the number of line lasers irradiated in the target space increases, a more accurate 3D map may be generated.

The present invention is not limited by the above embodiments and the accompanying drawings. For those of ordinary skill in the art to which the present invention pertains, it will be apparent that the components according to the present invention can be substituted, modified and changed without departing from the technical spirit of the present invention.

100: lidar device 110: laser light source unit
111: laser diode 112: diffraction grating unit
113: shutter unit 114: auxiliary light source unit
120: image sensor unit 130: image processing unit

Claims (7)

a laser light source for sequentially irradiating a plurality of line lasers into the target space;
an image sensor unit that detects the line lasers reflected in the target space, respectively, and individually generates corresponding detection images; and
The laser pattern corresponding to the line laser is extracted from the detection image to generate coordinate information in the target space for the laser pattern, and the coordinate information generated from each detection image is collected, A lidar device including an image processing unit for generating a three-dimensional map.
According to claim 1, wherein the laser light source unit
a laser diode generating laser light of a set wavelength;
a diffraction grating unit dividing the laser light into a plurality of line lasers traveling in different optical paths; and
LiDAR device, characterized in that it comprises a shutter (shutter) for individually opening or closing the light path.
According to claim 1, wherein the laser light source unit
The lidar device further comprising an auxiliary light source for outputting a visible light laser that displays a sensing region to which the line laser is irradiated in the target space.
The method of claim 2, wherein the diffraction grating unit
By generating a plurality of line lasers parallel to the horizontal direction,
LiDAR apparatus, characterized in that the plurality of line lasers are divided so as to proceed in optical paths of different angles in a vertical direction.
5. The method of claim 4, wherein the shutter unit
One of the plurality of optical paths is opened and all others are closed,
LiDAR device, characterized in that sequentially opening the plurality of light paths from top to bottom or from bottom to top.
The method of claim 2, wherein the shutter unit
A lidar device, characterized in that the light path is opened or closed by using a liquid crystal shutter.
In a 3D map generation method using a lidar device,
(a) irradiating any one of the N line lasers into the target space;
(b) generating a detection image by sensing the line laser reflected in the target space;
(c) extracting a laser pattern corresponding to the line laser from the detection image, and generating coordinate information in the target space for the laser pattern; and
(d) generating N pieces of coordinate information by repeating steps (a) to (c) for N line lasers, and generating a three-dimensional map of the target space by collecting the N pieces of coordinate information A method of generating a 3D map comprising a.

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