KR20130130358A - Three dimensional scanning system and three dimensional image acqusition method using the same - Google Patents

Abstract

The present invention relates to a three-dimensional scanning system and a three-dimensional image acquisition method using the three-dimensional scanning system capable of obtaining high decomposition resolution at a long range and capable of sensing a wide angle at a short range with low costs. The three-dimensional scanning system according to the present invention is a sensor system for measuring the distance of an objective by receiving light reflected from the objective after radiating pulse light, wherein the sensor system comprises an optical source apparatus for generating the pulse light; an optical transceiver including an optical transceiving module for radiating the pulse light and receiving the reflected light of the pulse light; a rotation apparatus for rotating the optical transceiver; and a control apparatus for controlling the optical source apparatus, the optical transceiver, and the rotation apparatus. The optical transceiver includes two or more optical transceiving modules, at least one of which has a different radiation angle from the other optical transceiving modules. [Reference numerals] (AA) +10 degrees to -30 degrees;(BB) +8 degrees to -8 degrees

Description

3D scanning system and 3D image acquisition method using same {THREE DIMENSIONAL SCANNING SYSTEM AND THREE DIMENSIONAL IMAGE ACQUSITION METHOD USING THE SAME}

The present invention relates to a scanning system for acquiring a three-dimensional image and a three-dimensional image acquisition method using the same. More specifically, a three-dimensional scanning system capable of obtaining wide-area near-field data and far-field data having a higher vertical resolution than conventional methods. And a 3D image acquisition method using the same.

The sensor system, called LIDAR (Light Detection And Ranging) or LADAR (Laser Detection And Ranging), emits pulsed light toward a target and then returns the energy of light that is reflected back to the target. It is a system that can calculate the distance, speed, etc. of a target by capturing it and converting it into an electrical signal.

Such lidar systems are widely applied in various fields such as speed radar guns, aviation geo-mapping devices, three-dimensional ground surveys, and underwater scanning.

Recently, the LiDAR system is a driving assistance application that enables the driver to automatically warn the driver in the event of a dangerous situation or to automatically adjust the speed of the vehicle, or an automatic driving device such as a tractor without a driver. Is expanding.

On the other hand, in order to apply a lidar system to a car driving at high speed, it is necessary to obtain dense point cloud information having a wide field of view in three dimensions.

As a technique for obtaining three-dimensional point group data of a wide viewing angle, US Patent Publication No. 2010-20306 discloses a multi-array laser diode and a multidetector (or single detector) that detects reflection of light emitted from the laser diode. And a housing for accommodating the laser diode and the multiple detector and a rotating means for rotating the housing at a high speed of 360 [deg.].

The multi-array laser diodes arranged in the lidar system are arranged such that the entire groups are arranged at different angles, so that the laser beams that are emitted as a whole are emitted at a predetermined angle, for example, in a range of 40 °. Point group data on height, that is, three-dimensional data can be obtained.

The system is composed of a first lidar system installed in a horizontal direction to obtain appropriate data in the height direction, and a second lidar system disposed slightly inclined downwardly compared to the first lidar system. Compared to the second LiDAR system, the IDA system obtains far point data from a remote location, and the second LiDAR system is able to obtain information about the surrounding area of the vehicle in operation, that is, the short-range point group data.

In the case of the first LiDAR system of the above system, in order to obtain the point cloud data for the long distance, it is necessary to increase the laser power emitted accordingly, which leads to a problem of increasing the volume of the device and increasing the cost of the unit device. In addition, as the distance increases, the distance between the point group data also increases, so that the vertical resolution of the acquired point group data is lowered, thereby lowering the reliability of the processed data.

U.S. Published Patent Application No. 2010-20306

The present invention has been made to solve the above-mentioned problems of the prior art, the first object of the present invention is to obtain a wide-angle data at close range and to obtain far-field data with excellent vertical resolution without increasing the light output at a distance. Therefore, it is to provide a three-dimensional scanning system that can be suitably used for unmanned driving devices, such as an auxiliary driving device or an intelligent robot of a car or agricultural machine running at high speed.

In addition, a second object of the present invention is to provide a three-dimensional scanning system that can increase the scanning speed compared to the prior art.

A third object of the present invention is to provide a three-dimensional image acquisition method that can obtain reliable three-dimensional point group data for long distance and short distance without increasing the light output.

As a means for solving the first problem, the present invention is a scanning system for obtaining a three-dimensional image by calculating the distance of the target by receiving the reflected light reflected from the target after emitting the pulsed light, the light source for generating a pulsed light An optical transmission and reception device comprising an apparatus, an optical transmission and reception module for emitting the pulsed light and receiving the reflected light of the emitted pulsed light, a rotation driving device for rotating and driving the optical transmission and reception device, the light source device, the optical transmission and reception device, and rotation And a control device for controlling a driving device, wherein the optical transmission and reception device comprises two or more optical transmission and reception modules, wherein at least one or more light emission angles of the two or more optical transmission and reception modules are different from other optical transmission and reception modules. Provide a dimensional scanning system.

In addition, the present invention as a means for solving the second problem, the pulsed light is generated by the scanning system for receiving the reflected light reflected from the target to calculate the distance of the target to obtain a three-dimensional image, generating the pulsed light An optical transmitting and receiving device including a light source device for emitting the pulsed light and receiving reflected light of the emitted pulsed light, a rotation driving device for rotating and driving the optical transmitting and receiving device, the light source device and the optical transmitting and receiving device And a control device for controlling the rotation driving device, wherein the optical transmission module comprises: a collimator for aligning the optical axis of the pulsed light provided from the light source; and a lens for decomposing the light passing through the collimator into a plurality of lenses; A lens for receiving the reflected light, a filter for filtering the light passing through the lens, and an electric scene from the filtered light. The 3D scanning system including a light receiving means provided comprising a photodiode for generating.

In addition, in the three-dimensional scanning system of the present invention, the optical transmitting and receiving device is composed of a first optical transmitting and receiving module and a second optical transmitting and receiving module, the optical transmitting and receiving module and the first optical transmitting and receiving module are opposite to each other. It may be disposed facing the direction.

In addition, in the three-dimensional scanning system of the present invention, the light emission angle of the first optical transmission module may be more than twice as large as the light emission angle of the second optical transmission module.

In addition, in the three-dimensional scanning system of the present invention, the light emission angle of the first optical transmission module is larger than the light emission angle of the second optical transmission module, the light emission angle of the second optical transmission module is the first optical It may be set to maintain a wide width that can cover a predetermined height set in the sense system at the reflected light detection limit distance of the transmission and reception module.

In the three-dimensional scanning system of the present invention, the pulsed light may be a pulse laser.

In addition, in the three-dimensional scanning system of the present invention, the light source device may be provided corresponding to the number of the optical transmission and reception module.

In addition, in the three-dimensional scanning system of the present invention, each of the light source device has a structure in which a plurality of laser diodes are arranged, the plurality of laser diodes can be emitted at the same time.

The present invention as a means for solving the third problem, the light source device for generating a pulsed light by a method of obtaining a three-dimensional image by measuring the distance of the target by receiving the reflected light reflected from the target after emitting the pulsed light And an optical transmitting and receiving device including two or more optical transmitting and receiving modules for emitting the pulsed light and receiving the reflected light of the emitted pulsed light, a rotation driving device for rotating and driving the optical transmitting and receiving device, the light source device, the optical transmitting and receiving device, and Using a device including a control device for controlling the rotation drive device, it provides a three-dimensional image acquisition method, characterized in that the light emission angle of at least one or more of the two or more optical transmission and reception modules.

In addition, in the three-dimensional image acquisition method of the present invention, two optical transmission and reception modules may be installed and the optical transmission and reception directions of the optical transmission and reception modules may be opposite to each other.

According to the present invention, since a narrow angle of light is used for long distance detection and a wide angle of light is used for near distance, the wide angle of view can be secured at a close distance and the density of point group data can be obtained at a long distance. This excellent data can be obtained.

In addition, according to the present invention, it is possible to lower the light output compared to the case of using a light of a wide angle to use a light of a narrow angle at a long distance.

In addition, according to the present invention, it is not necessary to use a laser of high power at a long distance, and a laser can be used at the same output at a long distance and a short distance, so that it can be driven with a single output, which is advantageous in reducing the volume of a three-dimensional scanning system. .

In addition, according to one embodiment of the present invention, the laser pulsed light on a line can be emitted at once, and the scanning speed can be significantly increased.

1 is a block diagram of a three-dimensional scanning system according to an embodiment of the present invention.
2 is a block diagram of each component of the 3D scanning system according to an exemplary embodiment of the present invention.
3 is a view for explaining the laser emission form of the three-dimensional scanning system according to an embodiment of the present invention.
4 is a view showing light emitted at different angles in a three-dimensional scanning system according to an embodiment of the present invention.
FIG. 5 is a diagram illustrating each resolution of light emitted at different angles and each resolution of an overlapping portion in a three-dimensional scanning system according to an exemplary embodiment of the present invention.
6 is a view for explaining a method of setting the light emission angle of the three-dimensional scanning system according to an embodiment of the present invention.

1 is a block diagram of a three-dimensional scanning system according to an embodiment of the present invention, Figure 2 is a block diagram of each configuration forming a three-dimensional scanning system according to an embodiment of the present invention.

As shown in Figures 1 and 2, the three-dimensional scanning system according to the present invention is a power unit 10 for providing a laser output, an optical transmission and reception unit 20 responsible for optical transmission and reception, the optical transmission and reception unit 20 And a control unit 40 for controlling the scanning unit 30 and the optical transmission / reception unit 20 and the scanning unit 30 to mechanically rotate the light source.

The power unit 10 receives an external power source (for example, a 24V power source), and supplies a main control power source 11 to supply power for operating the control unit 40, and the optical transmission and reception unit 20. It comprises a high voltage transformer 12 for providing a high voltage power to the light source constituting the.

The light transmitting / receiving unit 20 includes a laser generator 21 for generating a laser which is a light source. In addition, optical transmission including a collimator 222 for aligning the optical axis of the laser generated from the laser generator 21, and a line generator lens 223 for dispersing the laser beam passing through the collimator 222 into a plurality of lights Means 220, a light receiving lens 231 for receiving the light emitted by the light transmitting means 22 is reflected back to the target, and a light from the light passing through the light receiving lens 231 A bandpass filter 232 for removing and outputting components below a frequency or above a specific frequency, a photodiode 233 for converting light passed through the bandpass filter 232 into an electrical signal, and the photodiode 233 An amplifier 234 for amplifying an electrical signal of the power amplifier; a peak detector 235 for detecting a specific peak from an electrical signal passing through the amplifier 234; and a strength of reflected light from a detection signal of the peak detector 235. The ADC 236 obtains a TDC, and the TDC measuring time from the information of the time discriminator 237 and the time discriminator 237 for obtaining the time of the reflected light from the signal amplified through the amplifier 234. It may include a light transmission module 22 including a light receiving means 230 including a 238.

In the embodiment of the present invention, as shown in FIG. 3, the pulse generator having a vertical line shape (red line on the drawing) can be emitted at a time by using the line generator lens 223 from one laser light source, thereby greatly increasing the scanning speed. It can increase.

The optical transmitting and receiving module 22 may be provided with two or more, and are arranged in a housing in a circular shape, for example, two at 180 °, three at 120 °, four at 90 °, and so on. It is preferable to arrange.

In consideration of the weight, volume and manufacturing cost of the device, it is most preferable to arrange two optical transmission / reception modules 22. For example, in the case of two optical transmission / reception modules 22, as shown in FIG. Likewise, arrange them in opposite directions. Each line generator lens 223 is formed to emit light at different angles. For example, when the light emission angle of one of the light transmission and reception module 22 is 40 °, the light emission angle of the other light transmission and reception module 22 is set differently to be 16 °.

Herein, the light emission angle means an angle at which light spreads in the vertical direction.

When the distance from the three-dimensional scanning system is close, even if the light emission angle is large, the vertical spacing of the point cloud data is maintained to some extent so that it is less influenced by analyzing the target through data analysis. However, when the distance from the 3D scanning system is far, for example, when the distance from the 3D scanning system is 200m, the distance between each light at the 200m point even if a plurality of lights that the unit scanner can emit is dense. Since are very far from each other, there is a problem that the vertical resolution of the point group data obtained therefrom is greatly reduced.

However, as in the embodiment of the present invention, when the pulsed light emitting angles of the two optical transmitting and receiving modules 22 are set differently, as shown in FIG. 4, from the light spreading wide such as 40 ° from the three-dimensional scanning system It is possible to secure the vertical data range that can be secured by detecting the target located at a wide angle to the widest angle, and the distance of the point cloud data can be shortened even at a long distance in the case of narrow spreading light such as 16 °. The degradation of the vertical resolution of the target can be prevented, thereby making it possible to obtain reliable data on the remote target.

Further, when the light emission angle is reduced, a laser with low output power can be easily used for reception, and further, a laser having the same output at a long distance and at a short distance can be used. Accordingly, the three-dimensional scanning system according to the present invention is capable of using a laser having a rather low output power while increasing the vertical resolution as compared with the conventional three-dimensional scanning system using one kind of laser light having a wide light emitting angle There is an advantage.

In addition, as shown in FIG. 5, even in a short distance, the light emission angles of the optical transmission module 22 that emits pulsed light at a wide angle and the optical transmission module 22 'that emits pulsed light at a narrow angle are different from each other. This has the effect of increasing the density of point group data obtained in the region where two lights overlap. That is, when only a wide angle is used, the angular resolution is only 1.25 degrees, and even in a narrow angle, the angular resolution is 0.42 degrees. In the case of overlapping portions, the angular resolution is very excellent at 0.36 degrees. Therefore, according to an exemplary embodiment of the present invention, there is an advantage in that an image located at a central portion of a short distance of a 3D imaging system can be obtained with excellent resolution.

On the other hand, in the case of using a plurality of optical transmission and reception module 22, the laser generator 21 is used to separate the light into two using a means such as a splitter using a single laser generator 21, or each Several laser generators 21 may be used in accordance with the number of optical transmission and reception modules 22.

In addition, a plurality of laser diodes may be integrated and used as respective light sources without using a line generator lens. In this case, each of the generated lasers can be controlled to the light emission angle through the lens disposed at the tip.

The scanning unit 30 is a device for rotationally driving the optical transmission / reception unit 20, and a driving shaft may transmit the housing 31 on which the optical transmission / reception unit 20 is mounted and the rotational driving force of the housing 31. And a motor controller 33 for controlling the motor.

The control unit 40 is a device capable of generating control signals for controlling the laser generator 21, the optical transmission / reception module 22, and the motor controller 32. The high performance controller 41 and the encoder counter Means such as 42 are provided.

Hereinafter, a three-dimensional image acquisition method using a three-dimensional scanning system having two optical transmission and reception modules will be described.

Through the control unit 40 shown in FIG. 2, the motor 32 is driven, and at the same time, a control signal is transmitted to the laser generator 21 so as to generate a pulse laser, and is received through the optical transmission / reception module 22. The distance from the target of each pulse laser is measured from the reflected light through the above-described circuit.

At this time, as shown in Figure 4, the angle of the light emitted from the first optical transmission module 22 is set to 40 ° wide, for example, the angle of the light emitted from the second optical transmission module 22 'is For example, set it narrow to 16 ° to obtain point cloud data.

As a result, as shown in FIG. 4, a wide angle point group data can be obtained from a 3D scanning system for a target located at a short distance, and a resolution of the vertical point group data can be increased for a target located far from the 3D scanning system. Can be. This makes it possible to similarly maintain the density of the point cloud data at a long distance or at a short distance, thereby enhancing the reliability of the processed data.

On the other hand, when the angle of the light emitted from the optical transmitter / receiver module is set wide, the individual light is spread over a large area, so that the detection distance of the reflected light which can be detected by using the same light source is also shortened. Is emitted to the space at the upper end where the angle of spread is large, there are many cases where there is no reflected light detected at a long distance, and too much unnecessary data is obtained because the portion near the sensor is irradiated at the lower end. Further, in order to obtain data for a long distance, for example, 200 m or more while maintaining a wide angle of emitted light, it is necessary to increase the output of the laser, which not only increases the volume and weight of the three-dimensional scanning system but also increases the manufacturing cost .

On the contrary, as in the embodiment of the present invention, when light having a narrow emission angle is used at the center of the region of interest to be detected, the detection distance of the reflected light can be far from the same laser output. That is, it becomes possible to use a laser having a low output in order to obtain the long-distance point cloud data.

6 is a view for explaining a process of adjusting the angle between the first optical transmission module and the second optical transmission module.

As shown in the figure, when the first optical T / R module spreads at a wide angle, the optical detection limit becomes shorter than that of the second optical T / R module. In this case, the second optical T / It is desirable to set such that the optical angle can be maintained to such an extent as to cover the minimum detection height required by the system.

10: power unit
20: optical transmission unit
30: scanning unit
40: control unit

Claims (10)

The scanning system that emits pulsed light and receives the reflected light reflected from the target to measure the distance of the target to obtain a three-dimensional image,
A light source device for generating pulsed light;
An optical transmission and reception device comprising an optical transmission and reception module for emitting the pulsed light and receiving the reflected light of the emitted pulsed light;
A rotary driving device for rotating the optical transmitting and receiving device;
A control device for controlling the light source device, the optical transmission and reception device, and the rotary drive device;
The optical transmitting and receiving device comprises two or more optical transmitting and receiving modules, wherein at least one of the two or more optical transmitting and receiving angles of the optical transmission module, characterized in that different from the other optical transmission and receiving module. The method of claim 1,
The optical transmission module,
Optical transmitting means including a collimator for aligning an optical axis of the pulsed light provided from the light source and a lens for decomposing a plurality of light passing through the collimator into a plurality;
And a light receiving means comprising a lens for receiving the reflected light, a filter for filtering the light passing through the lens, and a photodiode for generating an electrical signal from the filtered light. The method of claim 1,
The optical transmitting and receiving device includes a first optical transmitting and receiving module and a second optical transmitting and receiving module, wherein the first optical transmitting and receiving module and the second optical transmitting and receiving module are arranged so that the optical transmitting and receiving faces in opposite directions to each other. 3D scanning system. The method of claim 3, wherein
3. The three-dimensional scanning system of claim 1, wherein the light emission angle of the first optical transmission module is greater than twice the light emission angle of the second optical transmission module. The method of claim 3, wherein
The light emission angle of the first optical transmission module is larger than the light emission angle of the second optical transmission module,
The light emission angle of the second optical transmission module is set so as to maintain a wide width that can cover a predetermined height set in the sense system at the reflected light detection limit distance of the first optical transmission module. The method of claim 1,
And the pulsed light is a pulsed laser. The method of claim 1,
And a light source device corresponding to the number of the optical transmission and reception modules. The method of claim 7, wherein
Each of the light source devices has a structure in which a plurality of laser diodes are arranged, and the plurality of laser diodes blink at the same time. After emitting the pulsed light and receiving the reflected light reflected from the target to measure the distance of the target,
An optical transmitting and receiving device comprising a light source device for generating pulsed light, an optical transmitting and receiving module for emitting the pulsed light and receiving the reflected light of the emitted pulsed light, a rotation driving device for rotating the optical transmitting and receiving device; Using a device including a light source device, a light transmitting and receiving device and a control device for controlling the rotary drive device,
And at least one or more light emission angles of the two or more optical transmission / reception modules. The method of claim 9,
And installing the two optical transmitting and receiving modules and making the optical transmitting and receiving directions of the optical transmitting and receiving modules opposite to each other.

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