KR20200139964A - Lidar optical apparatus - Google Patents

Abstract

The present invention relates to a lidar optical device which provides improved resolution and detection performance of a polygonal mirror block. The lidar optical device comprises: a polygon mirror block; a laser module assembly; a rotation unit accurately detecting a rotation speed and rotation position of the polygon mirror block and inserted into an inner hollow unit of the polygon mirror block to rotate the polygon mirror block for a function for precisely positioning the laser module assembly; a magnetic encoder deterring the rotation speed and rotation position of the polygon mirror block at an end extending below a rotation shaft disposed to pass through the center of the rotation unit; and a laser adjuster coupled to a lower portion of the laser module assembly and fixed to a lower case to perform an alignment function for positioning between the laser module assembly and the polygonal mirror block.

Description

Lidar optical device {LIDAR OPTICAL APPARATUS}

The present invention relates to a lidar optical device, and more particularly, a lidar optical device having a function for detecting the rotational speed and rotation position of a rotating polygon mirror block and adjusting the position of a laser module assembly. It is about.

Recently, in order to detect surrounding terrain or objects in automobiles or mobile robots, LIDAR (Light Detection And Ranging) optical devices, which are laser radar devices, are widely used.

Such a lidar optical device is a device that emits pulsed laser light into the atmosphere and measures distances, objects, or atmospheric phenomena using the reflected light from a reflector or scatterer in the atmosphere, and calculates the time of the reflected light as a clock pulse. It has a resolution of 5m with a frequency of 30MHz and 1m with 150MHz.

In this way, the LiDAR optical device measures the distance, speed, and shape of the object to be measured or measures the distance, speed, and shape of the object to be measured by irradiating laser light to the surrounding area and using the time and intensity of the reflected light reflected and returned to the surrounding object or terrain. Scan precisely.

Such a lidar optical device is widely applied in various fields, such as sensors for detecting obstacles in front of robots and unmanned vehicles, radar guns for speed measurement, aerial geo-mapping devices, 3D ground surveys, and underwater scanning.

Accordingly, in the lidar optical device, in order to reflect the laser beam received and transmitted at an accurate position and at an accurate timing, it is required to detect states such as the rotational speed and rotational position of the mirror block operating at high speed. In addition, it is necessary to implement a high-resolution sensor for recognizing the rotational speed and rotational position even during high-speed rotation.

Additionally, in the lidar optical device, an alignment function for precise positioning between the laser module receiving and transmitting laser beams and the mirror block is required to improve the scanning performance.

As a conventional technique for solving the above-described requirements, Korean Patent Application Publication No. 10-2017-0078031 (2017.07.07.) discloses a scanning lid having a variable scanning vertical area.

The background technology relates to a scanning lidar in which the scanning vertical area is variable, and a reflection mirror that reflects a pulsed laser traveling toward a measurement target is controlled to rotate 360 degrees through a motor, and at the same time, a single or a small number of lasers and a receiver and Through a structure in which the mirror rotates in the vertical direction, it provides a scanning lidar with a variable scanning vertical area that can secure safety based on obtaining 3D spatial information by performing a scan on a wide area where the vertical area is extended. I have to.

However, the prior art discloses a configuration including a motor that rotates the reflection mirror 360 degrees, and an angle adjustment unit that controls the reflection mirror to be tilted in a vertical direction, but the rotation speed of the mirror block operating at high rotation speed And it is different from improving the alignment performance for precise positioning between the laser module receiving and transmitting laser beams and the mirror block in order to improve the scanning performance and the sensor realization function capable of recognizing and detecting the rotational position.

The present invention was derived to solve the problems of the prior art, and an object of the present invention is to recognize and detect the rotational speed and rotational position of a mirror block operating at high speed in a lidar optical device. In order to improve the sensor implementation function and the scanning performance, it is intended to provide alignment performance for precise positioning between the laser module receiving and receiving laser beams and the mirror block.

Another object of the present invention is a means for detecting the position using the principle that the resistance value changes according to the flow of the magnetic field generated when the magnet rotates, and the laser module assembly and the position adjustment for precise position adjustment of the laser beam. It is to provide a high-performance lidar optical device with a simple structure made up of means that can be used.

A light detection and ranging radar (LIDAR) optical device according to an aspect of the present invention for solving the above technical problem is a laser module assembly that performs a laser transmission and reception operation, and the laser transmission on the front surface of the laser module assembly. And a polygonal mirror block that forms a reflection path for receiving and, a rotation unit inserted into the inner hollow of the polygonal mirror block to rotate the polygonal mirror block, and extends to a lower portion of a rotation shaft disposed to pass through the center of the rotation unit A magnetic encoder to detect the rotational speed and rotation position of the polygonal mirror block at the end that is coupled to the lower part of the laser module assembly and fixed to the lower case to perform an alignment function to adjust the position between the laser module assembly and the polygonal mirror block. It can be configured including an adjuster.

The magnetic encoder of the present invention may be characterized in that it rotates by being configured to cross each other so that a plurality of N and S poles cross each other so as to have a certain gap inside and face each other in a cylindrical shape of a certain length.

In addition, in the magnetic encoder of the present invention, an encoder PCB consisting of an electronic circuit for detecting a change in resistance according to a magnetic field strength is coupled to an upper side, and the encoder PCB may include a Hall sensor.

In addition, the laser adjuster of the present invention is composed of a slider that can position the laser module assembly in the longitudinal direction and a rotating rotor that can adjust the rotational position of the laser module assembly, and can control rotation and movement in the longitudinal direction. I can.

Accordingly, the laser adjuster may be configured to configure rail parts on both sides of the board frame so that the slider can adjust the longitudinal movement along the rail part.

According to the above-described lidar optical device, there is an effect of providing an improvement in resolution and detection performance of a polygonal mirror block through a sensor configuration capable of recognizing and detecting the rotational speed and rotational position of a mirror block operating at a high speed.

In addition, the present invention provides alignment performance for precise positioning between the laser module and the mirror block, and thus spatial data while effectively controlling the reflection and scattering angle of the laser beam by the combination structure of the laser modules, the mirror block and the rotating unit. It can provide the effect of maximizing the spatial scan performance that can secure

1 is a perspective view showing the appearance of a lidar optical device according to an embodiment of the present invention.
FIG. 2 is a perspective view illustrating a state in which an outer case is removed from the lidar optical device of FIG. 1.
3 is a plan view illustrating a state in which the outer case is removed from the lidar optical device of FIG. 1.
FIG. 4 is a cross-sectional view schematically illustrating a mirror rotating part in a cross section taken along BB in FIG. 3.
5 is a perspective view showing a coupling relationship between a mirror rotation unit and an encoder magnet in FIG. 4.
6 is a perspective view showing the configuration of the N-pole and S-pole of the encoder magnet.
7 is a schematic cross-sectional view of the laser module in the AA cross section in FIG. 3.
FIG. 8 is a bottom view showing a laser adjuster coupled to the laser module of FIG. 6.

The terms or words used in this specification and claims should not be construed as being limited to their usual or dictionary meanings, and the inventor may appropriately define the concept of terms in order to describe his own invention in the best way. It should be interpreted as a meaning and concept consistent with the technical idea of the present invention based on the principle that there is.

Therefore, the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiment of the present invention, and do not represent all the technical spirit of the present invention, and thus various equivalents that can replace them at the time of application It should be understood that there may be water and variations.

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

1 is a perspective view showing the appearance of a lidar optical device according to an embodiment of the present invention, FIG. 2 is a perspective view showing a state in which an outer case is removed from the lidar optical device of FIG. 1, and FIG. This is a plan view of the optical device with the outer case removed.

The lidar optical device 100 according to the present embodiment includes an upper case 110 and a lower case 130 as shown in FIGS. 1 to 3, and is disposed on at least one surface of the upper case 110. A window 120 is provided to transmit the internal laser beam to the outside and the laser beam reflected from the outside to the inside.

In addition, the lidar optical device 100 includes a laser module assembly 10, a polygonal mirror block 20, and a rotation unit 30 installed on the lower case 130.

The laser module assembly 10 includes a first laser module and a second laser module. The first laser module and the second laser module are installed to irradiate a laser to different regions of the first mirrors disposed on the polygonal mirror block 20. The first laser module and the second laser module are provided to emit laser light toward at least one mirror on the surface of the polygonal mirror block 20 while being parallel to each other or at an acute angle to each other when the light emitting points are matched.

The first or second laser module includes at least one laser diode and at least one plurality of photodiodes emitting pulsed laser beams. Here, the laser diode corresponds to the racer transmission module, and the photodiode corresponds to the laser reception module.

The polygonal mirror block 20 includes a plurality of mirrors disposed in a radial direction on the outer surface of the mirror block body. The plurality of mirrors reflect the first laser beam of the first laser module and the second laser beam of the second laser module on the front surface of the first laser module and the second laser module to transmit signals and reflect the laser beam for signal reception. In charge. Each of the plurality of mirrors may be attached to or coated on each surface of the side surfaces of the polygonal column shape.

In addition, as shown, when a plurality of mirrors are provided with the second to eighth mirrors sequentially arranged in the order described in the counterclockwise direction from any one mirror, for example, the first mirror, each of the first to eighth mirrors Has a rectangular plate shape, is perpendicular to a horizontal line, and has a different inclination angle of each of the reflective surfaces of the first to eighth mirrors in a vertical direction passing through each of the first to eighth mirrors, and the first mirror The inclination angles of each reflective surface from to the eighth mirror are arranged to gradually decrease or increase in a counterclockwise direction about the rotation axis of the polygonal mirror block 20 by the rotation unit 30. In this configuration, it goes without saying that the arrangement of the first to eighth mirrors is not limited to the counterclockwise direction, but may be arranged clockwise.

Therefore, the polygonal mirror block 20 is not limited to having 8 mirrors in the shape of a square plate, and a plurality of mirrors attached to the flat surface of each outer side of a polygonal column shape such as a pentagonal column shape or a 20-angle column shape. Can be equipped with.

In the above description, the polygonal mirror block 20 on which a plurality of mirrors are installed may be referred to as a mirror block having a polygonal column shape. This polygonal mirror block 20 is installed to rotate by a rotating unit 30 having a hollow portion thereof, inserted into the hollow portion and coupled by fastening means such as screws, nuts, and bolts. According to the above-described configuration, since the lidar optical device can be simply configured by simply rotating the polygonal mirror block 20 through the rotation unit 30 such as a single motor, the components of the device can be reduced and the structure can be simplified. .

The plurality of mirrors of the polygonal mirror block 20 may have 5 or more to 20 or less mirrors arranged to be inscribed or circumscribed to a circle corresponding to the longitudinal section of the outer peripheral surface of the mirror block body, and 8 to 12 mirrors It is desirable to have them.

At least one of the first mirrors and the second mirrors may have a flat, curved, or aspherical shape. The arrangement of the laser modules or the emission angle of the laser light may be adjusted according to the shape of the reflective surfaces of the first mirrors and the second mirrors.

The rotation unit 30 includes a support plate overlapping on the bottom plate of the lower case 130 and a motor support portion 31 extending vertically upward from the support plate, as shown in FIGS. 5 to 7. The motor support unit 31 is configured to seat and support a rotating unit such as a motor or a rotating unit 30 in the hollow portion of the polygonal mirror block 20.

The rotation shaft 32 protruding from the top of the rotation unit 30 is disposed to pass through the center of the polygonal mirror block 20. At this time, a part of the motor support part 31 surrounds and supports the rotation unit 30 and extends to an upper inner side of the polygonal mirror block 20, and is closely fixed to the mirror unit 20 by a fastening means. According to this configuration, the polygonal mirror block 20 is coupled to the rotation shaft 32 of the rotation unit 30 so as to stably rotate without substantial shaking.

Accordingly, in the present invention, in order to accurately detect the rotational speed and rotational position of the polygonal mirror block 20, a magnetic encoder 33 that rotates at the end of the rotational unit 30 extending downward is configured.

4 is a cross-sectional view schematically showing a mirror rotating part in the BB cross section in FIG. 3, FIG. 5 is a perspective view showing a coupling relationship between the mirror rotating part in FIG. 4 and the encoder magnet, and FIG. 6 is a N-pole and S-pole of the encoder magnet Is a perspective view showing the configuration of.

This is a cylindrical shape of a certain length at the lower end of the rotation shaft 32 extending from the inside of the polygonal mirror block 20 as shown, and a circular magnetic encoder 33 consisting of a certain number of N and S poles is provided inside. Position.

In addition, an encoder PCB 35 consisting of an electronic circuit for detecting a change in resistance according to the magnetic field strength is coupled to the upper side of the magnetic encoder 33, and the encoder PCB 35 includes a Hall sensor 34. Becomes. The Hall sensor 34 is a magnetic resistance sensor.

The magnetic encoder 33 is a device that detects a position using the principle that the resistance value of the Hall sensor 34 changes according to the flow of a magnetic field generated when the magnet rotates.

The Hall sensor 34 is a sensor using a magneto-resistance effect, and uses a property in which an alloy thin film containing a ferromagnetic metal as a main component changes a resistance value according to an external magnetic field strength.

The change in resistance occurring at this time can be obtained by using the encoder PCB 35 to obtain a sinusoidal signal such as a sin signal and a cos signal, and this can be achieved by Trigonometry, Table Compensation, and ATO (Angle Tracking Observe). The rotation speed and rotation direction can be detected by applying the same method.

In addition, in order to improve the resolution and detection performance of the polygonal mirror block 20 requiring high-speed rotation, the magnetic encoder 33 of the present invention has a certain gap (GAP) and is configured so that a plurality of N and S poles cross each other to face each other. do.

In addition, since the output signal includes errors due to the Hall sensor 34 itself and an external magnetic field, a process of compensating for this may be added.

FIG. 7 is a cross-sectional view schematically illustrating the laser module in section A-A in FIG. 3, and FIG. 8 is a bottom view illustrating a laser adjuster combined with the laser module in FIG. 6.

As shown, in the present invention, in order to perform an alignment function for positioning the laser module assembly 10 and the polygonal mirror block 20, the laser adjuster 40 board is additionally incorporated into the laser module assembly 10. It is coupled to the lower side of the, and is configured to be coupled to the lower case 130 to be fixed.

The laser module assembly 10 is configured to include first and second laser transmitting modules for transmitting a laser beam and first and second laser receiving modules for receiving a laser beam reflected from the lidar optical device, thereby scanning You can expand the range or improve the scan speed.

Accordingly, the laser module assembly 10 needs to perform precise position adjustment for laser beam scanning with the polygonal mirror block 20, and for this purpose, a laser adjuster capable of positioning by being combined with the laser module assembly 10 It is to constitute (40).

The laser adjuster 40 is composed of a slider 41 capable of moving the laser module assembly 10 in the longitudinal direction and a rotating rotor 42 capable of adjusting the rotational position of the laser module assembly 10 In addition, a rail part 43 may be configured to be connected to the slider from the inside of the frame so that the position of the laser adjuster 40 in the longitudinal direction can be adjusted. Accordingly, the slider 41 may be controlled to move in a longitudinal direction along the rail part 43.

Therefore, the laser adjuster 40 is coupled with the rotary rotor 42 at the lower center of the laser module assembly 10, and the rotary rotor 42 is coupled on the same plane as the slider 41, and the slider 41 Both sides are connected to the rail unit 43 so that the laser module assembly 10 as a whole can provide precise movement in the rotation and length direction.

In this way, the lidar optical device 100 according to the present embodiment rotates the polygonal mirror block 20 including a plurality of mirrors having a gradually increasing or decreasing inclination angle to change the reflection angle of the laser to By using multiple laser transmission modules with different laser beam emission positions or laser beam emission angles while transmitting and receiving laser beams on the scanning line corresponding to the line, the scanning angle and resolution can be changed and the desired resolution can be effectively improved. In order to be able to obtain it, state recognition through a magnetic encoder 33 for detecting the rotational speed and rotation position of the polygonal mirror block 20 and position adjustment between the laser module assembly 10 and the polygonal mirror block 20 It can be achieved by performing the alignment function through the laser adjuster 40 for.

On the other hand, although the control unit is not specifically mentioned in the above-described embodiment, the lidar optical device according to the present embodiment or the lidar device 100 having the same may further include a control unit. In that case, the control unit controls the on-off operation or rotation speed of the rotation unit 30 such as a motor, controls the transmission and reception operation of the laser module assembly 10, and transmits the received signal to an external device. Can be implemented. In that case, the control unit is configured to synchronize the laser beam transmission timing of the laser transmission module and the rotation position of the mirror block 20 to a preset position and timing to perform a control operation.

The above-described control unit may be implemented as at least one device selected from a logic circuit, a programming logic controller, a microcomputer, a microprocessor, and the like, and may have a communication module or be coupled to a communication module. The communication module communicates with an external device through an intranet, the Internet, a vehicle network, etc., and can transmit a signal or data related to the distance to a target or target detected through laser scanning to the external device. Such a control unit may be mounted in the case of the laser module assembly 10, but is not limited thereto.

Meanwhile, although not shown in the drawings, the lidar device 100 may be provided with a wiring for supplying power, an adapter, or a power supply means. The power supply means may have an internal power supply or a rechargeable power supply, in which case the lidar device may be implemented for use as a removable device.

Using the above-described lidar device of the present invention, it is possible to effectively reflect and emit a laser beam emitted from a laser module to a desired target range, and to effectively receive a laser beam reflected from the outside to detect a target by a laser beam or Target measurement can be performed effectively. That is, the rotating mirror block enables effective adjustment of the incident angle and reflection angle of the laser beam emitted through the window from the inside of the outer case through the mirrors on the mirror block surface, and the laser modules rotating at a certain angle are It is possible to effectively perform a laser scanning operation using another area.

According to the above-described configuration, it is possible to maximize the spatial scanning performance for securing spatial data while effectively controlling the reflection and scattering angle of the laser beam by the combination structure of the laser modules, the mirror block, and the rotating unit in the lidar device. There is an advantage.

It is natural that the present invention can be variously modified in addition to the above-described embodiments. The lidar device of the present invention may be generally applied to a vehicle, but the present invention is not limited thereto. That is, the lidar optical device and the lidar device having the same according to the present invention can be applied not only to vehicles, but also to moving objects such as robots, ships, helicopters, drones, etc., and the movement of buildings, columns, towers, etc. is restricted. It can be applied to a fixture without limitation.

As described above, in the detailed description of the present invention, preferred embodiments have been described, but those of ordinary skill in the technical field of the present invention will not depart from the spirit and scope of the present invention described in the following claims. It will be appreciated that various modifications and changes can be made to the present invention.

100: lidar optical device 110: upper case
120: window 130: lower case
10: laser module assembly 20: polygonal mirror block
30: rotation unit 31: motor support
32: rotating shaft 33: magnetic encoder
43: Hall sensor 35: Encoder PCB
40: laser adjuster 41: slider
42: rotating rotor 43: rail portion

Claims (5)

As a lidar (light detection and ranging radar) optical device,
A laser module assembly that performs laser transmission and reception operations,
A polygonal mirror block forming a reflection path for transmitting and receiving the laser on the front surface of the laser module assembly,
A rotating unit inserted into the hollow inside of the polygonal mirror block to rotate the polygonal mirror block,
A magnetic encoder for sensing the rotational speed and rotational position of the polygonal mirror block at an end extending to a lower portion of the rotational shaft disposed to pass through the center of the rotational unit, and
A lidar optical device comprising a laser adjuster coupled to a lower portion of the laser module assembly and fixed to the lower case to perform an alignment function for positioning a laser module assembly and a polygonal mirror block. The method according to claim 1,
The magnetic encoder is a lidar optical device, characterized in that it rotates by being configured to cross each other so as to face each other and have a certain gap inside the magnetic encoder in the form of a cylinder of a certain length. The method according to claim 1,
The magnetic encoder is a lidar optical device, characterized in that the encoder PCB consisting of an electronic circuit for detecting a change in resistance according to the magnetic field strength is coupled to the upper side, and the encoder PCB includes a Hall sensor. The method according to claim 1,
The laser adjuster is composed of a slider that can position the laser module assembly in the longitudinal direction and a rotating rotor that can adjust the rotational position of the laser module assembly, and can control rotation and movement in the longitudinal direction. The lidar optical device. The method of claim 4,
The laser adjuster is a lidar optical device, characterized in that it is configured to configure rails on both sides of the board frame so that the slider can adjust the longitudinal movement along the rails.

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