KR102512169B1 - LiDAR Scanner - Google Patents

Abstract

A lidar scanner is initiated. In the lidar scanner according to an embodiment of the present invention, a light receiving mirror having a through hole is formed on a rotating mirror, and a light transmitting unit and a light receiving unit are disposed above and behind the light receiving mirror, respectively, so that the laser light is emitted from the light transmitting unit. Through the through-hole on the light-receiving mirror, it is reflected on the rotating mirror and sent out, and the reflected laser light reflected from the object is reflected back through the rotating mirror and the light-receiving mirror and received by the light receiving unit without interference, thereby increasing the receiving efficiency of the reflected laser light, The overall height of the scanner is minimized by arranging the light transmitting unit and the light receiving unit above and behind the light receiving mirror, respectively.

Description

LiDAR Scanner {LiDAR Scanner}

The present invention relates to a lidar scanner, and more particularly, by constructing a separate light-receiving mirror on top of a rotating mirror, disposing a light transmitter and a light receiver on the top and rear of the light-receiving mirror, respectively, so that reflected laser light reflected from an object The present invention relates to a lidar scanner that increases the reception efficiency of laser reflected light and minimizes the overall height of the scanner by allowing the light to be received by the light receiving unit in a state in which interference with the light receiving unit is minimized.

In general, a light detection and ranging (LiDAR) system transmits laser light to an object, receives reflected laser light that is reflected or scattered by the object, and analyzes it to determine the distance, direction, speed, and distance to the object. It is a system capable of sensing temperature, material distribution and concentration characteristics.

Since the means for object detection and distance measurement is laser light, the lidar system is often called a laser radar or a 2-dimensional or 3-dimensional scanner. The measurement accuracy is high, and the surrounding information can be grasped accurately.

In other words, this lidar system can be said to be a device that precisely draws the surroundings by emitting laser pulses, receiving the light reflected from surrounding objects and measuring the distance to the object, and instead of radio waves It means a radar that uses light on the radar, and the principle is the same as that of a traditional radar, but the actual use technology and application range are different because the wavelength of the electromagnetic wave used is different.

In addition, the LIDAR system is used not only for the distance to an object, but also for measuring the speed and direction of movement, temperature, ambient air quality analysis and concentration. It can detect aerosols, so it is used for weather observation, and it is used to precisely draw the terrain, guide the landing of an aircraft, or as a device for recognizing the surroundings of an autonomous vehicle.

In addition, it is used to find out the chemical composition of gases mixed in the air by using a phenomenon in which the wavelength of light that scatters well for each molecule is different, and its application fields are limitless.

A LiDAR Scanner according to the prior art operated as an example of such a lidar system includes a light transmitter for transmitting laser light, and a mirror unit for reflecting the laser light transmitted from the light transmitter through a rotating mirror rotating at a constant angle. Consisting of a motor driving unit that repeatedly rotates and drives the mirror unit, a light receiving unit that reflects and receives the reflected laser light reflected or scattered from an object through a rotating mirror, and a signal processing unit that processes information received by the light receiving unit. do.

However, the conventional lidar scanner as described above is a coaxial type in which the light transmitting unit and the light receiving unit are placed on the same axis, and the structure of the LD (Laser Diode) module of the light transmitting unit for transmitting laser light according to the structural characteristics is There is a disadvantage in that the receiving lens of the light receiving unit is covered and the receiving efficiency (measurement efficiency) of the reflected laser light is lowered.

In addition, the coaxial type lidar scanner has a disadvantage in that the overall height of the scanner is increased because a light receiving lens having a long focal length must be vertically disposed.

Korean Patent Publication No. 2020-0009757

An embodiment of the present invention configures a light receiving mirror having a through hole on the upper part of the rotating mirror, and arranges a light transmitting unit and a light receiving unit on the upper part and the rear side of the light receiving mirror, respectively, so that the laser light from the light transmitting unit passes through the through hole on the light receiving mirror. Provides a lidar scanner that enhances the reception efficiency of the laser reflection light by reflecting it on the rotating mirror and sending it out, and the laser reflected light reflected from the object is reflected back through the rotating mirror and the light receiving mirror and received by the light receiving unit without interference. want to do

In addition, an embodiment of the present invention is to provide a lidar scanner that minimizes the overall height of the scanner by arranging a light transmitting unit and a light receiving unit above and behind the light receiving mirror, thereby increasing utilization in applications with limited standards.

In one or more embodiments of the present invention, a light transmission unit for transmitting laser light, a mirror unit for reflecting the laser light transmitted from the light transmission unit through a rotating mirror rotating at a predetermined angle, and a range of a predetermined angle for the mirror unit. A motor drive unit that repeatedly rotates and drives the object, a light receiver that reflects and receives the reflected laser light reflected or scattered from an object through a rotating mirror, and a signal processor that processes the information received by the light receiver. In the scanner, the mirror unit includes a rotating mirror rotatably installed in the motor driving unit; And a through hole is formed in the center corresponding to the upper part of the rotation mirror and fixed to the fixed frame at a predetermined angle, and passes the laser light output from the light transmission unit through the through hole to the rotation mirror, and from the rotation mirror A lidar scanner including a light-receiving mirror for reflecting reflected laser light to the light-receiving unit may be provided.

a laser module (11) fixed on an upper bracket fixed to a case corresponding to an upper portion of the through hole on the light receiving mirror; a lens holder 13 fixed on the upper bracket to correspond to a lower portion of the laser module; and first and second lenses respectively installed on upper and lower portions of the lens holder to convert the laser light into parallel light.

In addition, the motor driving unit is fixed to the motor through the motor bracket on the lower base plate; a rotating plate whose center is fixed on the rotating shaft of the motor and gear teeth are formed at regular intervals along the outer circumference to be rotated and driven by the motor; and a photosensor fixed on the base plate through a sensor bracket to sense the gear teeth at the rear of the rotating plate and detect the rotating direction and number of rotations of the rotating plate.

Here, the photosensor may be formed of a photo interrupter.

In addition, the rotating mirror may be installed in a rotating mirror case inclined at a predetermined angle through a support bracket on the rotating plate so that a reflective surface faces upward.

In addition, the light-receiving mirror may be installed in a light-receiving mirror case that is spaced apart from the rotating mirror at the same angle at a predetermined interval and inclined to the fixing frame so that the reflecting surface faces the reflecting surface of the rotating mirror.

The light receiving unit may include a lens mount fastened to a fixing holder connected to the fixing frame corresponding to a rear side of the light receiving mirror; a light-receiving lens built inside the lens mount and condensing the reflected laser light reflected from the light-receiving mirror; and a light receiving element installed inside the fixing holder to convert the reflected laser light condensed from the light receiving lens into an electrical signal and output the converted signal.

In addition, the signal processing unit may be formed of a control board (PCB) fixed to the rear of the light receiving unit and having a control logic for converting an electrical signal output from the light receiving unit into an image signal and outputting the converted image signal.

In addition, the fixing frame may be installed toward the front on an upper part of a support frame that is erected and fixed to the rear on a lower base plate.

In the lidar scanner according to an embodiment of the present invention, a light receiving mirror having a through hole is additionally configured on the top of the rotating mirror of the mirror unit, and a light transmitting unit and a light receiving unit are disposed above and behind the light receiving mirror, respectively. The laser light is reflected on the rotating mirror through the through hole on the light receiving mirror and sent out, and the reflected laser light reflected from the object is reflected again through the rotating mirror and the light receiving mirror to minimize interference with the structure of the light transmitting unit and reach the light receiving unit. It can be received, so there is an effect of increasing the reception efficiency (ie, measurement efficiency) of the laser reflected light.

In addition, the lidar scanner according to an embodiment of the present invention has the effect of increasing utilization even in applications with limited specifications by minimizing the overall height of the scanner by separately arranging the light transmitting unit and the light receiving unit above and behind the light receiving mirror, respectively. .

1 is a perspective view of a lidar scanner according to an embodiment of the present invention.
2 is a front view of a lidar scanner according to an embodiment of the present invention.
3 is a half cross-sectional view of a lidar scanner according to an embodiment of the present invention.
4 is an operation explanatory diagram of a lidar scanner according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

However, since the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of description, the present invention is not necessarily limited to what is shown in the drawings, and the thickness is enlarged to clearly express various parts and regions. was

In addition, in order to clearly describe the embodiments of the present invention, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same components throughout the specification to be described.

1 is a perspective view of a coaxial lidar scanner according to an embodiment of the present invention, Figure 2 is a front view of a coaxial lidar scanner according to an embodiment of the present invention, Figure 3 is a coaxial lidar scanner according to an embodiment of the present invention is a half section of

The lidar scanner according to an embodiment of the present invention is a problem due to the structural characteristics of a coaxial type lidar scanner in which the conventional light transmitter and the light receiver are placed on the same axis, the LD (LD of the light transmitter for transmitting laser light) The disadvantage that the structure of the Laser Diode module obstructs the receiving lens of the light receiving unit and reduces the receiving efficiency of reflected laser light, and the disadvantage that the height of the scanner is too high because the receiving lens with a long focal length is vertically arranged along with the light transmitting unit is solved. It is to do.

1 to 3, the lidar scanner according to an embodiment of the present invention includes a light transmitting unit 10, a mirror unit 20, a motor driving unit 30, a light receiving unit 40, and a signal processing unit 50. include

First, the light transmission unit 10, the mirror unit 20, the motor driving unit 30, the light receiving unit 40, and the signal processing unit 50, which are the main components of the lidar scanner, are as shown in FIG. It is configured inside the case C, and is a structure for fixing these components inside the case, a base plate 1 is provided at the bottom, and a support frame 3 is built on one rear side of the base plate 1 installed

In addition, a fixing frame 5 is installed on the upper part of the support frame 3 toward the front, and an upper bracket 7 for installing the light transmitter 10 is fixed to the upper inner surface of the case C. .

Here, the case (C) is indicated by a dotted line for convenience of description.

And the light transmitter 10 is configured to transmit laser light, and is composed of a laser module 11, a lens holder 13, and first and second lenses l1 and l2.

The laser module 11 is fixed on the upper bracket 7 fixed to the case C corresponding to the upper portion of the mirror unit 20, and a laser diode LD outputting laser light is embedded therein. .

The lens holder 13 is fixed on the upper bracket 7 to correspond to the lower part of the laser module 11, and the inside thereof is hollow.

The first and second lenses L1 and L2 are respectively installed on the upper and lower portions of the lens holder 13 to convert the laser light output from the laser diode LD into parallel light so that the mirror unit 20 ) is sent to

The mirror unit 20 functions to reflect the laser light transmitted from the light transmission unit 10 through a rotating mirror M2 at a constant angle that rotates, and together with the rotating mirror M2, a separate light receiving mirror M1 ).

First, the rotating mirror M2 is rotatably installed in the motor driving unit 30, the light receiving mirror M1 is disposed corresponding to the top of the rotating mirror M2, and has a through hole H at the center thereof. This is formed and fixed to the fixing frame 5 at a certain angle and installed.

That is, the light receiving mirror M1 passes the laser light output from the laser diode LD of the light transmitter 10 through the through hole H, and the laser light passing through the through hole H The light is reflected by the rotating mirror M2, changes direction, and is irradiated to an external object (not shown).

The reflected laser light reflected from the object (not shown) is first reflected by the rotating mirror M2 and transferred to the light receiving mirror M1, and the light receiving mirror M1 reflects it again and changes its direction. It has a function of secondary reflection to the light receiver 40.

Further, the motor driver 30 has a function of repeatedly rotating and driving the reflective mirror M2 of the mirror unit 20 within a range of a predetermined angle.

That is, the motor driving unit 30 is composed of a motor 31, a rotating plate W, and a photosensor PS.

The motor 31 is fixedly installed on the lower base plate 1 upward through the motor bracket 33.

The rotation plate (W) has a center fixedly installed on the rotation shaft 35 of the motor 31, and gear teeth (WG) are formed at regular intervals along the outer circumference, so that the motor 31 is driven repeatedly to rotate is configured to

The photosensor (PS) detects the gear teeth (WG) at the rear of the rotary plate (W), detects the rotation direction and rotation number of the rotary plate (W), and outputs the signal, and the base plate (1) ) is fixed through the sensor bracket 37 on one rear side of the upper garment.

Here, the photosensor PS may be formed of a photo interrupter based on the principle of combining a light emitting diode and a photo transistor so that the photo transistor receives light emitted from the light emitting diode and operates the transistor.

On the other hand, on the rotating plate (W), the rotating mirror (M2) is installed in a rotating mirror case (MC2) installed inclined at a predetermined angle through a support bracket (21) with the reflecting surface facing upward, and the rotating plate (W ) is configured to rotate together according to the rotation of

In addition, the light-receiving mirror M1 is spaced apart at the same angle as the rotating mirror M2 at a predetermined interval, and the light-receiving mirror case MC1 inclinedly installed on the fixed frame 5 has a reflective surface of the rotating mirror M2. It is installed facing the reflective surface.

At this time, each reflecting surface of the water pipe mirror M1 and the rotating mirror M2 maintains a state of being inclined at a predetermined angle with respect to the rotating plate W.

The light receiving unit 40 has a function of receiving reflected laser light that is reflected or scattered from an object and reflected by the rotating mirror M2 and the water pipe mirror M1 and returned.

That is, the light receiving unit 40 is composed of a lens mount LC, a light receiving lens L3, and a light receiving element 43.

The lens mount LC is fastened to the fixing holder 41 connected to the fixing frame 5 corresponding to the rear of the light receiving mirror M1.

The light-receiving lens L3 is built into the lens mount LC, and functions to condense the reflected laser light reflected from the light-receiving mirror M1.

The light receiving element 43 is located inside the fixing holder 41 and is connected to the signal processing unit 50 to convert the reflected laser light condensed from the light receiving lens L2 into an electrical signal to the signal processing unit 50. print out

The signal processing unit 50 processes the information received by the light receiving unit 40, and is composed of a control board (PCB), and the control board (PCB) is fixed to the rear of the light receiving unit 40 to It has a control logic that converts the electrical signal output from the light receiver 40 into an image signal and outputs the converted image signal.

Here, the control board (PCB) is also electrically connected to the photosensor (PS) and is configured to receive rotation direction and rotation number information of the rotation plate (W).

4 is an operation explanatory diagram of a lidar scanner according to an embodiment of the present invention.

The LiDAR scanner according to an embodiment of the present invention is a system using a laser, and the laser has a different wavelength depending on the purpose. Generally, a light having a wavelength of 600-1000 nm can be used, and a longer length is used to reduce damage to human eyes. Wavelength light can be used.

Referring to FIG. 4, in the operation of the LIDAR scanner having the above configuration, first, the laser diode (LD) of the light transmission unit 10 generates a pulse laser under the control of the signal processing unit 50, It transmits through the second lens (L1) (L2).

Then, the first and second lenses L1 and L2 convert the received pulse laser beam into parallel light and rotate the mirror M2 through the through hole H1 of the light receiving mirror M1 of the mirror unit 20. , and the rotating mirror M2 reflects the pulse laser again and transmits it to the object (reflector).

Accordingly, the reflected light reflected from the object (reflector) is reflected to the light receiving mirror M1 through the reflective surface of the rotating mirror M2 of the mirror unit 20, and the reflected light reflected by the light receiving mirror M1 is While passing through the light receiving lens L3 of the receiving unit 40, the light is condensed by the light receiving element 43, converted into an electrical signal, and transmitted to the signal processing unit 50.

Meanwhile, the motor driving unit 30 rotates the rotating mirror M2 by driving the motor 31, and the rotational speed of the motor 31 can be controlled by the signal processing unit 50.

The signal processing unit 50 calculates the distance and speed to the object (reflector) using the electrical signal converted from the light receiving unit 40. The pulse width of the pulse laser transmitted by the light transmitting unit 10 and the previously set A transmission repetition rate including the number of pulse laser beams transmitted by the light transmitter 10 within a set period of time, a reception repetition rate including the number of reflected lights received by the light receiver 40 within a preset time period, and a power value of the pulse laser beam Depending on the distance and speed to the object (reflector), it can be actively changed.

Therefore, in the lidar scanner according to an embodiment of the present invention, the light receiving mirror M1 having the through hole H is separately configured on the top of the rotation mirror M2, and the light transmitting unit 10 is placed on the top of the light receiving mirror M1. ) is disposed, and the light receiving unit 40 is disposed at the rear so that the laser light output from the laser diode LD of the light transmitting unit 10 passes through the through hole H on the light receiving mirror M1 to the rotating mirror M2. The reflected laser light reflected from the reflective object can be reflected through the rotation mirror M2 and the light receiving mirror M1 and received by the light receiving unit 40 without interfering with the structure of the light transmitting unit 10. there is.

Accordingly, the LiDAR scanner according to an embodiment of the present invention can increase the receiving efficiency of the reflected laser light.

In addition, since the light transmitting unit 10 and the light receiving unit 40 can be disposed above and behind the light receiving mirror M1, the overall height of the scanner can be minimized, thereby increasing utilization even in applications with limited specifications.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and is easily changed from the embodiment of the present invention by a person having ordinary knowledge in the art to which the present invention belongs, so that the same It includes all changes within the scope recognized as appropriate.

1: base plate
3: support frame
5: fixed frame
7: upper bracket
C: case
10: optical transmitter
11: laser module
13: lens holder
LD: laser diode
L1, L2: first and second lenses
20: mirror part
21: support bracket
M1: light receiving mirror
M2: rotating mirror
MC1: light-receiving mirror case
MC2: Rotating Mirror Case
H: through hole
30: motor driving unit
31; motor
33; motor case
35: axis of rotation
37: sensor bracket
PS: photosensor
W: turntable
WG: Gearchi
40: optical receiver
41: fixed holder
43: light receiving element
L3; light receiving lens
LC: lens mount
50: signal processing unit
PCB: control board

Claims (19)

delete delete delete delete delete delete delete delete delete In lidar scanners,
It consists of a laser module with a built-in laser diode to output laser light, and a lens holder in which first and second lenses are installed to convert the laser light into parallel light corresponding to the lower part of the laser module. a light transmitter that transmits light;
a mirror unit having a light receiving mirror formed with a through hole in the center fixed at a predetermined angle and reflecting the laser light transmitted from the light transmitting unit through the through hole of the light receiving mirror through a rotating mirror rotating at a predetermined angle;
a motor drive unit that repeatedly rotates and drives the rotation plate fixing the rotation mirror of the mirror unit within a predetermined angular range by a motor drive;
a light receiving unit for condensing reflected laser light, which is reflected or scattered from an object and reflected back through the rotation mirror and the light receiving mirror through a light receiving lens, and converts the signal through a light receiving element; and
It includes; a signal processing unit for processing the information received by the optical receiver,
The mirror unit includes a rotating mirror fixed on a rotating plate of the motor driving unit, and a through hole formed in the center corresponding to an upper portion of the rotating mirror and fixed to a fixed frame at a predetermined angle. a light-receiving mirror for passing output laser light through the rotating mirror and reflecting laser reflected light reflected from the rotating mirror to the light receiving unit;
The light transmitter includes a laser module having a built-in laser diode for outputting laser light and fixed on an upper bracket fixed to a case to correspond to an upper portion of the through hole on the light receiving mirror, and a laser module to correspond to a lower portion of the laser module. It includes a lens holder fixed on the upper bracket, and first and second lenses respectively installed on the top and bottom of the lens holder to convert the laser light into parallel light,
The light receiving unit includes a lens mount fastened to a fixing holder connected to the fixed frame corresponding to a rear side of the light receiving mirror, a light receiving lens built inside the lens mount and condensing reflected laser light reflected from the light receiving mirror, and , a light-receiving element installed inside the fixing holder to convert the reflected laser light condensed from the light-receiving lens into an electrical signal and output it;
The lidar scanner disposing the light transmitting unit and the light receiving unit above and behind the light receiving mirror, respectively. delete According to claim 10,
the rotating mirror
A lidar scanner installed so that the reflective surface faces upward in a rotating mirror case installed at an angle at an angle through a support bracket on the rotating plate. According to claim 12,
The light-receiving mirror
A lidar scanner installed so that a reflective surface faces the reflective surface of the rotating mirror in a light-receiving mirror case that is spaced apart at a predetermined interval at the same angle as the rotating mirror and installed obliquely to the fixed frame. delete According to claim 10,
the motor drive unit
A motor fixed on a lower base plate through a motor bracket;
a rotating plate whose center is fixed on the rotating shaft of the motor and gear teeth are formed at regular intervals along the outer circumference to be rotated and driven by the motor; and
a photosensor fixed on the base plate through a sensor bracket to detect the gear teeth at the rear of the rotating plate and to detect the rotating direction and number of rotations of the rotating plate;
A lidar scanner that includes a. According to claim 15,
The photosensor is
A lidar scanner consisting of a photo interrupter. delete According to claim 10,
The signal processing unit
A lidar scanner comprising a control board fixed to the rear of the light receiving unit and having a control logic for converting and outputting an electrical signal output from the light receiving unit as an image signal. According to claim 10,
The fixed frame
A lidar scanner that is installed facing the front on top of a support frame that is erected and fixed to the rear on the lower base plate.

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