KR102678771B1 - Lidar apparatus for uniform incidence angle of light incident on photodetector using receiving optical system and method for operating the same - Google Patents

Abstract

According to various embodiments of the present invention, a light source emitting first light; a light detector that detects a second light, which is light reflected by an object located on the scan area, among the first lights; Receive the emitted first light and reflect it toward the scan area, receive the second light reflected from the object, control the angle at which the second light is incident on the photo detector to be constant, and control the second light to be constant. a scanning unit that transmits light toward the optical detector; and a signal processing unit that obtains distance information about the object using a detection result of the light detector.
According to various embodiments of the present invention, by applying a lidar device using an optical axis adjustment optical system, it is possible to scan a wide angular range without deteriorating performance, and can also measure a short-distance range within several meters.

Description

LIDAR device and method of operating the same for maintaining the angle of incidence of light incident on the light detector using a receiving optical system

The present invention relates to a LiDAR device and a method of operating the same.

LIDAR (Light Detection and Ranging) irradiates light, such as a laser, to an object and then analyzes the light reflected from the object to determine the physical properties of the object, such as distance, direction, speed, temperature, material distribution, and concentration characteristics. It is one of the remote sensing devices that can measure LIDAR can measure the physical properties of an object more precisely by utilizing the advantages of a laser that can generate pulse signals with high energy density and short period.

LIDAR uses a laser light source of a specific wavelength or a tunable laser light source as a light source and is used in various fields such as 3D image acquisition, weather observation, measuring the speed or distance of a subject, and autonomous driving. For example, LIDAR is mounted on aircraft and satellites and used for precise atmospheric analysis and observation of the global environment, and is mounted on spacecraft and exploration robots and is used as a means to supplement camera functions such as measuring the distance to a subject.

In addition, simple LiDAR sensor technologies are being commercialized on the ground for long-distance measurement and vehicle speed violation enforcement. Recently, it has been used as a laser scanner or 3D video camera and is being used in 3D reverse engineering and driverless cars.

Republic of Korea Patent Publication No. 10-2299264 (2021.09.01.) Republic of Korea Patent Publication No. 10-2263182 (2021.06.03.)

The purpose of the present invention is to provide a LiDAR device that can scan a wide angular range without deteriorating performance and can measure short-distance ranges of several meters.

Other unspecified objects of the present invention can be additionally considered within the scope that can be easily inferred from the following detailed description and its effects.

In the LiDAR device according to an embodiment of the present invention for achieving the above-described object, there is provided a light source that emits first light; a light detector that detects a second light, which is light reflected by an object located on the scan area, among the first lights; Receive the emitted first light and reflect it toward the scan area, receive the second light reflected from the object, control the angle at which the second light is incident on the photo detector to be constant, and control the second light to be constant. a scanning unit that transmits light toward the optical detector; and a signal processing unit that obtains distance information about the object using the detection result of the light detector.

Here, the scanning unit includes a reflection unit configured to reflect the emitted first light toward the object, reflect the second light reflected from the object toward the light detector, and adjust a scan area; and a driving unit connected to the reflector to drive the reflector.

Here, the reflection unit includes: a first mirror unit that adjusts a vertical field of view (FOV) of the scan area; a second mirror unit that adjusts a horizontal field of view (FOV) of the scan area; and a third mirror unit that controls the angle at which the second light is incident on the photo detector to be constant using the tilt angle of the first mirror unit.

Here, the first mirror unit and the third mirror unit are MEMS (Micro Electro Mechanical Systems) mirrors, and the second mirror unit is a polygon mirror.

Here, the signal processing unit is characterized in that it adjusts the scan area by tilting and driving the MEMS mirror in the vertical direction and rotating the polygon mirror in the horizontal direction using the driving unit.

Here, it further comprises an optical window for transmitting the first light obtained from the scanning unit and reflected toward the scan area and the second light reflected from the object and obtained from the scanning unit. do.

Here, the optical window includes a window unit that transmits first light obtained from the scanning unit and reflected toward the scan area and second light reflected from the object and obtained by the scanning unit; a frame portion providing a structure for fixing the window portion; and at least two light reflection mirrors fixed to the frame unit to reflect the first light.

Here, the second mirror unit has at least three surfaces for reflecting the first light reflected from the first mirror unit toward the object and reflecting the second light reflected by the object towards the third mirror unit. It is characterized by including.

Here, the at least two light reflecting mirrors include: a first reflecting surface that reflects the first light reflected from one surface of the second mirror unit; and a second reflective surface that reflects the first light reflected from the first reflective surface to the other surface of the second mirror unit, wherein the other surface of the second mirror unit is configured to reflect the first light reflected from the second reflective surface. characterized in that it is reflected toward the third mirror unit.

Here, the at least two light reflection mirrors include: a first reflection mirror located at the left edge of the frame unit; and a second reflection mirror located at a right edge of the frame, wherein the signal processing unit uses the first reflection mirror to change the third mirror when the second mirror rotates to a predetermined first driving range. The driving angle of the mirror is controlled, and when the second mirror rotates to a predetermined second driving range, the driving angle of the third mirror is controlled using the second reflection mirror.

Here, when the first light in the scan area deviates from the first scan area corresponding to one side to the left based on the center of the optical window, the signal processing unit uses the first reflection mirror to 1 A first angle, which is a tilt angle of the third mirror unit that causes light to be incident on the optical detector, is obtained, and the first light is transmitted to the second side corresponding to the other side opposite to the one side based on the center of the optical window in the scan area. 2 When the irradiation deviates from the scan area to the right, a second angle, which is a tilt angle of the third mirror unit, is obtained using the second reflection mirror to allow the first light to be incident on the photo detector, and the third mirror It is characterized in that the control unit is tilted and driven within a range between the first angle and the second angle.

Here, the scanning unit includes a transmitting member that adjusts the first light incident from the light source to become parallel light; and a receiving member that condenses the second light and makes it incident on the photodetector, wherein the photodetector is comprised of an InGaAs-based PIN type, APD type, or SPAD type.

In a method of operating a LiDAR device performed in a LiDAR device including a light source, a light detector, a scanning unit, and a signal processing unit according to an embodiment of the present invention to achieve the above-described object, the light source, a light detector, a scanning unit, and A LiDAR device operating method performed in a LiDAR device including a signal processing unit includes the steps of the light source emitting first light; The scanning unit receives the emitted first light and reflects it toward the scan area, receives the second light reflected from the object, and controls the angle at which the second light is incident on the photo detector to be constant. , transmitting the second light toward the light detector; detecting, by the light detector, a second light that is light reflected by an object located on a scan area among the first lights; and obtaining, by the signal processing unit, distance information about the object using the detection result of the light detector.

As described above, according to an embodiment of the present invention, by applying a lidar device using an optical axis adjustment optical system, a wide angular range can be scanned without performance degradation, and a short-distance range within several meters can also be measured. .

Even if the effects are not explicitly mentioned here, the effects described in the following specification and their potential effects expected by the technical features of the present invention are treated as if described in the specification of the present invention.

1 to 2 are diagrams for explaining a LiDAR device according to an embodiment of the present invention.
3 to 4 are diagrams for explaining in detail a LiDAR device according to an embodiment of the present invention.
Figure 5 is a diagram for explaining an optical window of a lidar device according to an embodiment of the present invention.
Figure 6 is a diagram for explaining the second mirror unit of the lidar device according to an embodiment of the present invention.
Figure 7 is a diagram for explaining a reflection mirror of an optical window according to an embodiment of the present invention.
Figures 8 and 9 are diagrams for explaining that the lidar device according to an embodiment of the present invention uses the first or second reflection mirror in response to the driving angle of the second mirror unit.
Figure 10 is a diagram for explaining how a LiDAR device acquires information on an object according to an embodiment of the present invention.
Figure 11 is a diagram for explaining the operation process of a LiDAR device according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. The present embodiments are merely intended to ensure that the disclosure of the present invention is complete and to provide common knowledge in the technical field to which the present invention pertains. It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims. Unless otherwise defined, all terms (including technical and scientific terms) used in this specification may be used with meanings that can be commonly understood by those skilled in the art to which the present invention pertains. Additionally, terms defined in commonly used dictionaries are not interpreted ideally or excessively unless clearly specifically defined.

The terms used in this application are only used to describe specific embodiments and are not intended to limit the invention. The singular terms include plural expressions, unless the context clearly dictates otherwise. In this application, terms such as “have,” “may have,” “includes,” or “may include” refer to features, numbers, steps, operations, components, parts, or combinations thereof described in the specification. It is intended to specify the existence, but should be understood as not excluding in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof. Terms containing ordinal numbers, such as second, first, etc., may be used to describe various components, but the components are not limited by the terms.

The above terms are used only for the purpose of distinguishing one component from another. For example, the second component may be referred to as the first component without departing from the scope of the present invention, and similarly, the first component may also be referred to as the second component. The term and/or includes any of a plurality of related stated items or a combination of a plurality of related stated items.

In this specification, identification codes (e.g., a, b, c, etc.) for each step are used for convenience of explanation. The identification codes do not describe the order of each step, and each step is clearly understood in the context. Unless a specific order is specified, it may occur differently from the specified order. That is, each step may occur in the same order as specified, may be performed substantially simultaneously, or may be performed in the opposite order.

Additionally, the term '~unit' used in this specification may mean software or hardware components such as FPGA (field-programmable gate array) or ASIC, and the '~unit' performs certain roles. However, '~part' is not limited to software or hardware. The '~ part' may be configured to reside in an addressable storage medium and may be configured to reproduce on one or more processors. Therefore, as an example, '~ part' refers to components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, and procedures. , subroutines, segments of program code, drivers, firmware, microcode, circuits, data structures, and variables. The functions provided within the components and 'parts' may be combined into a smaller number of components and 'parts' or may be further separated into additional components and 'parts'.

Hereinafter, various embodiments of the LiDAR device according to the present invention will be described in detail with reference to the attached drawings.

The embodiments described in this specification can be widely applied in various fields such as sensors for detecting obstacles in robots and unmanned vehicles, radar guns for speed measurement, aerial geo-mapping devices, 3D ground surveys, and underwater scanning.

1 to 2 are diagrams for explaining a LiDAR device according to an embodiment of the present invention.

Referring to FIGS. 1 and 2 , the LIDAR device 10 may include a light source 100, a scanning unit 200, a light detector 300, and a signal processing unit 400.

The light source 100 may be a device that emits light. For example, the light source 100 may emit light in the infrared region. Using light in the infrared range can prevent it from mixing with natural light in the visible range, including sunlight. However, it is not necessarily limited to the infrared region, and the light source 100 can emit light in various wavelength regions. In these cases, correction to remove information from mixed natural light may be required.

The light source 100 may emit first light L1. According to one embodiment of the present invention, the light source 100 may be a fiber laser. A fiber laser can be implemented to have a laser wavelength in the 1.5 to 1.7 um band, kW peak power, and MHz laser pulse repetition rate.

The scanning unit 200 receives the emitted first light (L1) and reflects it toward the scan area, receives the second light (L2) reflected from the object 20, and the second light (L2) is transmitted to the light detector. The incident angle can be controlled to be constant, and the second light L2 can be transmitted toward the light detector 300.

Controlling the angle at which the second light L2 is incident on the photo detector 300 to be constant may mean controlling the optical path through which the second light L2 is incident on the photo detector 300 to be constant.

The scanning unit 200 will be described in more detail with reference to FIGS. 3 and 4 .

The light detector 300 may detect the second light L2, which is light reflected (or scattered) by the object 20 located on the scan area, among the first light L1.

The light detector 300 may convert the second light L2 reflected or scattered from the object 20 among the first light L1 into an electrical signal, for example, a current. The first light L1 emitted from the light source 100 is irradiated to the object 20 and may be reflected or scattered by the object 20 . Among the first light L1, the light reflected or scattered by the object 20 is called the second light L2. The first light L1 and the second light L2 may have substantially the same wavelength and different intensities.

According to one embodiment of the present invention, the photodetector 300 may be a single-element photodetector. Single-element photodetectors are connected by optical fibers. The laser spot focused on the receiving member 230, which will be described later, is focused on an optical fiber, and the optical fiber can transmit the laser beam to a single-element photo detector. Here, the single-element photo detector may be an InGaAs-based PIN type, APD type, or SPAD type.

The photo detector 300 may further include a current-voltage conversion circuit that converts the output current into voltage and an amplifier (not shown) that amplifies the amplitude of the voltage. In addition, the photo detector 300 may further include a filter that filters an electrical signal of a specific frequency, for example, a high-pass filter.

The optical fiber-connected single-element photodetector has higher sensitivity and response speed than the array-type photodetector used in general LiDAR, and can receive laser signals at high speed, thereby improving the resolution of 3D image information compared to general LiDAR.

The signal processing unit 400 may obtain distance information about the object 20 using the detection result of the light detector 300. The signal processing unit 400 may determine the distance from the LIDAR device 10 to the object 20 located on the scan area based on the detected second light L2. The signal processing unit 400 may calculate the distance to the object 20 based on the light emission time of the light source 100 and the light detection time of the light detector 300.

Additionally, the signal processing unit 400 can control the operation of each component of the LiDAR device 10, such as the light source 100, the scanning unit 200, and the light detector 300.

More specifically, the signal processing unit 400 can control the output and pulse repetition rate of the light source 100 and the rotation angle of the first reflector 241 and the second reflector 242, which will be described later. there is. The signal processing unit 400 may receive the second light L2 and calculate distance information of the object 20 with respect to three-dimensional coordinates.

According to an embodiment of the present invention, the signal processing unit 400 may adjust the signal intensity of the first light L1 based on a threshold and a weight.

More specifically, when the signal intensity of the second light (L2) received by the photodetector 300 is lower than the first threshold, the signal processing unit 400 determines the signal intensity of the transmitted first light (L1) and the first The signal intensity of the first light L1 emitted by the light source 100 may be adjusted to have a signal intensity equal to a value multiplied by a weight (eg, 1.3).

When the signal intensity of the second light L2 received by the photo detector 300 is greater than the first threshold and less than the second threshold, the signal processing unit 400 combines the signal intensity of the transmitted first light L1 with the second threshold. The signal intensity of the first light L1 emitted by the light source 100 may be adjusted to have a signal intensity equal to a value multiplied by 2 weights (for example, 1.1).

When the signal intensity of the second light L2 received by the photo detector 300 is greater than the second threshold, the signal processing unit 400 controls the signal intensity of the transmitted first light L1 and a third weight (for example, , 0.8), the signal intensity of the first light L1 emitted by the light source 100 can be adjusted to have a signal intensity equal to the value multiplied by , 0.8).

When the signal intensity of the second light (L2) received by the light detector 300 has the same value as the first threshold, the signal processing unit 400 determines the signal intensity of the transmitted first light (L1) and the first weight. The first light (e.g., 1.3) emitted by the light source 100 to have a signal intensity equal to the product of the average value (in the above example, 1.2) of the second weight (e.g., 1.1) The signal strength of L1) can be adjusted.

When the signal intensity of the second light (L2) received by the light detector 300 has the same value as the second threshold, the signal processing unit 400 determines the signal intensity of the transmitted first light (L1) and the second weight. The first light emitted by the light source 100 to have a signal intensity equal to the product of (e.g., 1.1), the third weight (e.g., 0.8), and the average value (in the above example, 0.95) You can adjust the signal strength of (L1).

LiDAR systems are being developed with the goal of wide scanning angles and high resolution. However, as the scanning angle widens, the optical system configuration of the receiver and the performance of the laser detector improve the performance of the LiDAR system, such as 3D image information measurement distance and spatial resolution. This is degraded.

Existing LIDAR systems use an array detector to receive light at a wide scan angle, or receive reflected light from a target through rotation. However, array detectors have the disadvantage of having a longer response time than single element detectors, which shortens the measurement distance and reduces angular resolution.

In addition, when the transmitter and receiver are separated, there is a problem in that the target distance cannot be measured in an area where the FOV (field of view) of the transmit laser beam and the receiving optical system do not overlap, and short distances of less than 1 meter cannot be measured. . In order to compensate for these shortcomings, we propose a LIDAR device and a method of operating the same that maintains a constant angle of incidence of light incident on the light detector 300 using a receiving optical system.

Not all blocks shown in FIGS. 1 and 2 are essential components, and in other embodiments, some blocks connected to the LIDAR device 10 may be added, changed, or deleted.

In FIG. 2 , the path of the first light L1 and the path of the second light L2 are shown to coincide between the scanning unit 200 and the object 20, but this is not necessarily limited.

3 to 4 are diagrams for explaining in detail a LiDAR device according to an embodiment of the present invention.

Referring to FIGS. 3 and 4 , the LIDAR device 10 may further include an optical window 500 and a display unit 700.

Additionally, the scanning unit 200 may include a transmitting member 210, a receiving member 230, a reflecting unit 240, and a driving unit 250.

The scanning unit 200 may include a transmission member 210 that adjusts the first light L1 incident from the light source 100 to become parallel light. The transmission member 210 may be formed as an optical lens so that the first light L1 output from the beam transmission optical fiber of the light source 100 becomes parallel light.

The scanning unit 200 may include a receiving member 230 that condenses the second light L2 reflected from the reflective surface of the optical axis adjusting unit 220 and makes it incident on the light detector 300 . The receiving member 230 may be formed as an optical lens to focus the second light L2 reflected from the object 20 and transmit it to the light detector 300.

The scanning unit 200 reflects the emitted first light L1 toward the object 20, reflects the second light L2 reflected from the object 20 toward the light detector 300, and scans the scan area. It may include a reflector 240 configured to adjust .

The scanning unit 200 may include a driving unit 250 that is connected to the reflecting unit 240 and drives the reflecting unit 240.

The reflection unit 240 includes a first mirror unit 241 that adjusts the vertical field of view (FOV) of the scan area, and a second mirror unit 242 that adjusts the horizontal field of view (FOV) of the scan area. ) and a third mirror unit 243 that controls the angle at which the second light L2 is incident on the light detector 300 to be constant using the tilt angle of the first mirror unit 241.

According to an embodiment of the present invention, the signal processing unit 400 controls the driving unit 250 so that the tilt angle of the third mirror unit 243 is the same as the tilt angle of the first mirror unit 241, thereby The tilt angle of (243) can be adjusted.

For example, when the tilt angle of the first mirror unit 241 is 25 degrees, the signal processing unit 400 controls the drive unit 250 so that the tilt angle of the third mirror unit 243 is also 25 degrees to turn the third mirror unit 241 on to 25 degrees. The tilt angle of the unit 243 can be adjusted. In this case, the direction in which the first mirror unit 241 and the third mirror unit 243 are tilted may be opposite to each other as shown in FIG. 4, regardless of the size of the tilt angle.

Through this method, the angle of the second light L2 incident on the photodetector 300 is maintained constant, so that a single-element photodetector can be used as the photodetector 300.

According to one embodiment of the present invention, the first mirror unit 241 and the third mirror unit 243 may be MEMS (Micro Electro Mechanical Systems) mirrors.

The conventional LiDAR optical system has the advantage of being able to scan a wide area by transmitting and receiving lasers through mechanical rotation, but has problems with mechanical durability. To solve this problem, a mechanical rotating part can be solved using a MEMS mirror.

The MEMS mirror scans the vertical FOV (Field of View) by tilting in the vertical direction, and the scan angle range of the LiDAR device 10 can be determined depending on the driving angle of the MEMS (Micro Electro Mechanical Systems) mirror. there is.

According to one embodiment of the present invention, the second mirror unit 242 may be a polygon mirror.

The polygon mirror rotates in the horizontal direction to scan a horizontal FOV (Field of View). The shape of the polygon mirror is not limited to the shape shown in Figure 4 and can be implemented in various forms, depending on the number of mirror surfaces of the polygon mirror. Accordingly, the scan angle range of the LiDAR device 10 may be determined.

The signal processing unit 400 can adjust the scan area by using the driving unit 250 to tilt the MEMS mirror in the vertical direction and rotate the polygon mirror in the horizontal direction.

The first mirror unit 241 performs a preset vertical rotation (tilt drive), and the second mirror unit 242 performs a preset horizontal rotation of the transmission light to direct the transmission light (first light) to the object ( Send to 20). The transmitted light may be transmitted along a scan path of a wavy waveform (eg, a sinusoidal waveform) within a predetermined scan area.

Here, the first mirror unit 241 and the second mirror unit 242 may be synchronized with each other to form a scan path. In other words, the first mirror unit 241 and the second mirror unit 242 can form a scan path of the transmission beam by matching the angles and speeds for horizontal rotation and vertical rotation through synchronization. Here, depending on the angle and speed settings for each of the horizontal and vertical rotations of the first mirror unit 241 and the second mirror unit 242, the scan path of the transmission beam has sizes in terms of amplitude, wavelength, period, etc. can be changed.

The LIDAR device 10 uses a first light L1 obtained from the scanning unit 200 and reflected toward the scan area and a second light L2 reflected from the object 20 and obtained from the scanning unit 200. It may further include an optical window 500 for transmission.

The optical window 500 transmits the first light (L1) obtained from the scanning unit 200 and reflected toward the scan area and the second light (L2) reflected from the object 20 and obtained from the scanning unit 200. A window unit 510, a frame unit 520 providing a structure for fixing the window unit 510, and at least two light reflection mirrors fixed to the frame unit 520 to reflect the first light L1 ( 531, 532).

At least two light reflection mirrors may include a first reflection mirror 531 located at the left edge of the frame portion 520 and a second reflection mirror 532 located at the right edge of the frame portion 520.

The display unit 700 can display 3D object image information output from the LIDAR system 10.

According to an embodiment of the present invention, the LIDAR device 10 may additionally include a received light quantity confirmation unit (not shown).

The received light quantity confirmation unit measures the received light quantity on the receiving side. The received light amount confirmation unit may be implemented as a module that measures the amount of received light reflected from the object 20 in conjunction with the optical window 500, the reflector 240, etc., but is not necessarily limited to this, and is linked to the light detector 300. Alternatively, it may be implemented in the form of hardware included in the light detector 300 or a program installed in the light detector 300.

The signal processor 400 may compare the measured received light amount with a preset reference light amount to adjust the transmitted light amount, the rotation angle of the reflector 240, the rotation speed of the reflector 240, etc.

Specifically, when the measured amount of received light is less than the reference light amount, the signal processor 400 determines the amount of transmitted light, the rotation angle of the reflector 240, and the rotation speed of the reflector 240 (for example, the first mirror unit 241). , the driving angle and driving speed of the second mirror unit 242 and the third mirror unit 243) can be adjusted.

The signal processor 400 may adjust the received light amount to be equal to or higher than the reference light amount using one of the first adjustment value, the second adjustment value, and the third adjustment value.

The signal processing unit 400 may adjust the transmission light amount by applying the first adjustment value to the existing transmission light amount, and then, if the measured received light amount is greater than or equal to the reference light amount, update the transmission light amount to the adjusted transmission light amount. In addition, the signal processor 400 adjusts the rotation angle of the reflector 240 by applying a second adjustment value to the rotation angle of the existing reflector 240, and when the measured amount of received light is greater than or equal to the reference light amount, the reflector 240 ) can be updated to the adjusted rotation angle. In addition, the signal processor 400 adjusts the rotation speed of the reflector 240 by applying a third adjustment value to the rotation speed of the existing reflector 240, and when the measured amount of received light is greater than or equal to the reference light amount, the reflector 240 ) can be updated to the adjusted rotation speed.

Meanwhile, even when one of the first adjustment value, the second adjustment value, and the third adjustment value is used, the signal processing unit 400 uses the first adjustment value, the second adjustment value, and the third adjustment value when the measured received light amount is less than the reference light amount. By applying each adjustment value sequentially, the received light amount can be adjusted to exceed the standard light amount.

For example, the signal processor 400 adjusts the amount of transmitted light by first applying the first adjustment value, and sequentially applies the second adjustment value and the third adjustment value, respectively, to adjust the rotation angle and reflection of the reflector 240. The rotation speed of unit 240 can be adjusted. Here, the order of applying the adjustment values may change depending on the settings.

Meanwhile, the signal processor 400 adjusts the condition using a combination of some adjustment values if the measured received light amount is less than the standard light amount even when one or all of the first adjustment values, second adjustment values, and third adjustment values are applied sequentially. Thus, the received light amount can be adjusted to exceed the standard light amount.

Specifically, the signal processing unit 400 may adjust the received light amount to more than the reference light amount by applying at least one adjustment value among the first adjustment value, the second adjustment value, and the third adjustment value.

For example, the signal processor 400 may adjust the amount of transmitted light and the rotation angle of the reflector 240 by combining the first adjustment value and the second adjustment value. Here, the signal processing unit 400 may reflect and combine the respective ratios of the first adjustment value and the second adjustment value differently. That is, the signal processing unit 400 can adjust the amount of transmitted light and the rotation angle of the reflection unit 240 by combining the first adjustment value and the second adjustment value with different weights.

The signal processing unit 400 can transform and combine the first adjustment value, the second adjustment value, and the third adjustment value into various conditions that can be combined, and then apply them to adjust the received light amount to a reference light amount or more.

All blocks shown in FIGS. 3 and 4 are not essential components, and in other embodiments, some blocks connected to the LIDAR device 10 may be added, changed, or deleted.

Figure 5 is a diagram for explaining an optical window of a lidar device according to an embodiment of the present invention.

The optical window 500 includes a first light L1 obtained from the scanning unit 200 and reflected toward the scan area, and a second light reflected from the object 20 and obtained from the scanning unit 200 (L1). L2) can be transmitted.

The optical window 500 transmits the first light (L1) obtained from the scanning unit 200 and reflected toward the scan area and the second light (L2) reflected from the object 20 and obtained from the scanning unit 200. A window unit 510, a frame unit 520 providing a structure for fixing the window unit 510, and at least two light reflection mirrors fixed to the frame unit 520 to reflect the first light L1 ( 531, 532).

The frame unit 520 uses a laser beam to prevent errors that may occur when the LIDAR device 10 performs a scanning operation and the first light L1 or the second light L2 is reflected by the frame unit 520 and returns. It may be formed of an absorber, or a material capable of absorbing the laser may be applied.

At least two light reflection mirrors 531 and 532 include a first reflection mirror 531 located at the left edge of the frame portion 520 and a second reflection mirror 532 located at the right edge of the frame portion 520. It can be included.

The signal processing unit 400 can synchronize the third mirror unit 243 to the first mirror unit 241 using the first reflection mirror 531 and the second reflection mirror 532 located in the frame unit 520. there is.

Here, synchronization is performed by the third mirror unit 243 such that the angle at which the second light L2 is incident on the photo detector 300 is constant in response to the driving angle of the first mirror unit 241 and the second mirror unit 242. ) may mean adjusting the vertical driving angle.

The first reflection mirror 531 or the second reflection mirror 532 will be described in more detail with reference to FIG. 7 .

Figure 6 is a diagram for explaining the second mirror unit of the lidar device according to an embodiment of the present invention.

The second mirror unit 242 reflects the first light L1 reflected from the first mirror unit 241 toward the object 20, and reflects the second light L2 reflected by the object 20. 3 It may include at least three surfaces 245, 246, and 247 for reflection toward the mirror unit 243.

To be described in more detail with reference to FIG. 6, the first light L1 emitted from the light source 100 is reflected by the first mirror unit 241 and is reflected by the first surface 245 of the second mirror unit 242. can be reached. Subsequently, the first light L1 that reaches the first surface 245 is reflected toward the object 20 by the first surface 245 of the second mirror unit 242.

Subsequently, the second light L2 reflected from the object 20 may reach the second surface 246 of the second mirror unit 242. Subsequently, the second light L2 that reaches the second surface 246 may be reflected by the second surface 246 toward the third mirror unit 243 or the light detector 300.

Figure 7 is a diagram for explaining a reflection mirror of an optical window according to an embodiment of the present invention.

At least two light reflection mirrors 531 and 532 reflect the first light L1 reflected from one surface of the second mirror unit 242 and a first reflection surface 535 that reflects the first light L1 reflected from one surface of the second mirror unit 242. It may include a second reflection surface 536 that reflects the first light L1 to the other surface of the second mirror unit 242.

Here, the other surface of the second mirror unit 242 may reflect the first light L1 reflected from the second reflection surface 536 toward the third mirror unit 243.

According to one embodiment of the present invention, as shown in FIG. 7, the light reflection mirrors 531 and 532 are in the form of a rectangular parallelepiped with one face concave inside the rectangular parallelepiped and shaved to form two faces (Corner Cube). form) can be formed.

In this case, the light reflection mirrors 531 and 532 have a total of seven sides.

As shown in FIGS. 8 and 9, the second reflecting mirror 532 has the same size and shape as the first reflecting mirror 531, and is arranged to be left and right symmetrical with respect to the central axis of the optical window 500. You can.

By using at least two light reflection mirrors 531 and 532, the scan angle of the first light L1 by the first mirror unit 241 can be compensated, and the optical axis of the first light L1 and the second light L1 The optical axis of the light L2 may be adjusted to be the same.

Figures 8 and 9 are diagrams for explaining that the lidar device according to an embodiment of the present invention uses the first or second reflection mirror in response to the driving angle of the second mirror unit.

When the second mirror unit 242 rotates to the first predetermined driving range, the signal processing unit 400 controls the driving angle of the third mirror unit 243 using the first reflection mirror 531, and When the second mirror unit 242 rotates within the predetermined second driving range, the driving angle of the third mirror unit 243 can be controlled using the second reflection mirror 532.

Referring to FIGS. 8 and 9, if described in more detail, the signal processing unit 400 operates the second mirror unit 242 within a predetermined first driving range (for example, 0 degrees to 45 degrees) as shown in FIG. 8. When rotated, the driving angle of the third mirror unit 243 can be controlled using the first reflection mirror 531.

The signal processing unit 400 uses the second reflection mirror 532 when the second mirror unit 242 rotates to a predetermined second driving range (for example, 0 degrees to -45 degrees) as shown in FIG. 9. Thus, the driving angle of the third mirror unit 243 can be controlled.

In the two cases described above, the signal processing unit 400 controls the driving angle of the third mirror unit 243 by controlling one surface of the second mirror unit 242 (FIG. 8) as shown in FIGS. 8 and 9. In the case of reference numeral 245, in the case of FIG. 9, reference numeral 247), the first reflective surface 535 of the light reflection mirrors 531 and 532, the second reflective surface 536, and the other surface of the second mirror unit 242 ( A driving angle of the third mirror unit 243 such that the first light L1 reflected sequentially through reference numeral 246 in the case of FIG. 8 and 245 in the case of FIG. 9 is incident at a constant angle toward the photo detector 300. It may mean controlling.

According to another embodiment of the present invention, the signal processing unit 400 determines that the first light L1 in the scan area deviates from the first scan area corresponding to one side to the left based on the center of the optical window 500. When the light is irradiated to In the case where the first light L1 in the area is irradiated so as to deviate to the right of the second scan area corresponding to the other side opposite to one side based on the center of the optical window 500, using the second reflection mirror 532 A second angle, which is a tilt angle of the third mirror unit 243 that causes the first light L1 to be incident on the photo detector 300, is obtained, and the third mirror unit 243 obtains the obtained first angle and the obtained It can be controlled to be tilted within a range between the second angles.

If the first light L1 is outside the range of the optical window 500, it cannot be irradiated toward the object 20, but in this case, it is reflected through the first reflection mirror 531 and the second reflection mirror 532. The first angle and the second angle, which are tilt angles of the third mirror unit 243, can be obtained so that the angle at which the first light L1 is incident toward the photo detector 300 is constant.

Accordingly, the signal processing unit 400 uses the driving unit 250 to control the third mirror unit 243 to tilt within a range between the first angle and the second angle, thereby allowing the first light L1 to return to the optical window. There is an effect that a preparation operation can be performed in preparation for irradiation within the range of (500), a tilt operation can be performed more quickly, and the second light L2 can be quickly incident on the light detector 300. .

Meanwhile, the first angle and the second angle may vary depending on the driving angles of the first mirror unit 241 and the second mirror unit 242.

The signal processing unit 400 may control the driving angle of the third mirror unit 243 whenever the LiDAR device 10 operates, and before the LiDAR device 10 performs the initial operation. It is natural that the driving angle of the third mirror unit 243 can be controlled.

The signal processing unit 400 may control the driving angle of the third mirror unit 243 every predetermined unit time (eg, 1 second).

The LiDAR device 10 transmits the second light (L2) incident to the receiving member 230 even if the scan angle of the first light (L1) changes depending on the reflector 240 (e.g., MEMS mirror and polygon mirror). Since the angle of ) is always constant, the photodetector 300 connected to an optical fiber (for example, a single-element photodetector connected to an optical fiber) can be used.

According to another embodiment of the present invention, the LIDAR device 10 may further include a driving angle counting unit (not shown), and the display unit 20 may include a first lamp (not shown) and a second lamp. (not shown) and a third lamp (not shown).

The driving angle counting unit (not shown) may calculate the total of the driving angles of the first mirror unit 241, the second mirror unit 242, and the third mirror unit 243, respectively. For example, if the first mirror unit 241 is driven by an angle of 15 degrees during the first driving operation, driven by an angle of 12 degrees during the second driving operation, and driven by an angle of 22 degrees during the third driving operation, the driving angle counting unit (not shown) can be calculated that the first mirror unit 241 has been driven a total of 49 degrees.

The first lamp turns on when the total driving angle of the first mirror unit 241 calculated by the driving angle counting unit is greater than or equal to a predetermined first threshold value (for example, 50,000) to inform the user of the first mirror unit ( It may be notified that the replacement cycle of the driving member connected to the driving unit 250 in order to drive 241) has elapsed.

The second lamp turns on when the total driving angle of the second mirror unit 242 calculated by the driving angle counting unit is greater than or equal to a predetermined second threshold (for example, 70,000) to inform the user of the second mirror unit ( It may be notified that the replacement cycle of the driving member connected to the driving unit 250 in order to drive 242) has elapsed.

The third lamp lights up when the total driving angle of the third mirror unit 243 calculated by the driving angle counting unit is greater than or equal to a predetermined third threshold (for example, 50,000) to inform the user of the third mirror unit ( It may be notified that the replacement cycle of the driving member connected to the driving unit 250 in order to drive 243) has elapsed.

Since the first mirror unit 241, the second mirror unit 242, and the third mirror unit 243 inevitably perform rotational or tilting operation frequently during the operation of the LiDAR device 10, the first mirror unit ( 241), damage and wear inevitably occur in the member that secures the second mirror unit 242 and the third mirror unit 243 to the lidar device 10 and the drive member connected to the drive unit 250, which is This may cause errors in the distance data of the object 20 output by the device 10.

The LiDAR device 10 notifies the user of the replacement cycle of the driving member connected to the driving unit 250 through the driving angle counting unit, the first lamp, the second lamp, and the third lamp, thereby By allowing the user to replace , errors in the distance data for the object 20 output by the LIDAR device 10 can be prevented.

Figure 10 is a diagram for explaining how a LiDAR device acquires information on an object according to an embodiment of the present invention.

Referring to FIG. 10, reference numeral 540 indicates a scan path 540 of the LiDAR device 10 according to an embodiment of the present invention. Looking at the scan path 540, scanning may begin at the upper left corner of the window unit 510 and may end at the lower right corner of the window unit 510.

Figure 11 is a diagram for explaining the operation process of a LiDAR device according to an embodiment of the present invention.

In step S101, the light source 100 may emit first light L1.

In step S102, the scanning unit 200 receives the emitted first light L1 and reflects it toward the scan area, receives the second light L2 reflected from the object 20, and The angle at which the second light is incident on the light detector 300 is controlled to be constant, and the second light L2 can be transmitted toward the light detector 300.

In step S103, the light detector 300 may detect the second light L2, which is light reflected by the object 20 located on the scan area, among the first light L1.

In step S104, the signal processing unit 400 may obtain distance information about the object 20 using the detection result of the light detector 300.

In FIG. 11, it is described that each process is executed sequentially, but this is only an illustrative explanation, and those skilled in the art can change the order shown in FIG. 11 and execute it without departing from the essential characteristics of the embodiments of the present invention. Alternatively, it may be applied through various modifications and modifications, such as executing one or more processes in parallel or adding other processes.

The operation process of the LiDAR device according to another embodiment of the present invention may be as follows.

The LIDAR device 10 can inspect the light source 100 and the scanning unit 200 by driving the reflecting unit 240 using the driving unit 250.

The signal processing unit 400 drives the second mirror unit 242 based on an initially set driving angle, and the driving angle of the second mirror unit 242 corresponds to either a predetermined first driving range or a second driving range. Depending on whether the light reflection mirror 531 or 532 is used, the third mirror unit 243 can be driven.

In addition, since the incident angle of the first light L1 toward the light detector 300 may vary depending on the driving angle of the first mirror unit 241, the signal processing unit 400 operates the first mirror unit 241. Each time the angle changes, one of the light reflection mirrors 531 and 532 is used depending on whether the driving angle of the second mirror unit 242 corresponds to a predetermined first driving range or a second driving range. The third mirror unit 243 can be driven.

On the other hand, although no special mention was made regarding the control unit (not shown) in the above-described embodiment, the LIDAR device 10 according to this embodiment may further include a control unit. In that case, the control unit may be implemented to transmit the received signal or the received and processed signal to an external device.

The above-mentioned control unit may be implemented with at least one device selected from a logic circuit, programming logic controller, microcomputer, microprocessor, etc., and may include a communication module or be coupled to a communication module. The communication module communicates with external devices through an intranet, Internet, vehicle network, etc., and can transmit signals or data related to the object 20 detected through laser scanning or the distance to the object 20 to the external device. This control unit can be simply mounted within the case of the LiDAR device 100.

Meanwhile, although not shown in the drawing, the LiDAR device 10 may be provided with wiring, an adapter, or a power supply means for supplying power. The power supply means may be provided with an internal power source or a rechargeable power supply, and may include a configuration that allows the LiDAR device 10 to be used in a detachable manner.

Even though all the components constituting the embodiments of the present invention described above are described as being combined or operated in combination, the present invention is not necessarily limited to these embodiments. That is, as long as it is within the scope of the purpose of the present invention, all of the components may be operated by selectively combining one or more of them. In addition, although all of the components may be implemented as a single independent hardware, a program module in which some or all of the components are selectively combined to perform some or all of the combined functions in one or more pieces of hardware. It may also be implemented as a computer program with . In addition, such a computer program can be stored in a computer readable media such as USB memory, CD disk, flash memory, etc. and read and executed by a computer, thereby implementing embodiments of the present invention. Recording media for computer programs may include magnetic recording media, optical recording media, etc.

The above description is merely an illustrative explanation of the technical idea of the present invention, and various modifications, changes, and substitutions can be made by those skilled in the art without departing from the essential characteristics of the present invention. will be. Accordingly, the embodiments disclosed in the present invention and the accompanying drawings are not intended to limit the technical idea of the present invention, but are for illustrative purposes, and the scope of the technical idea of the present invention is not limited by these embodiments and the attached drawings. . The scope of protection of the present invention should be interpreted in accordance with the claims below, and all technical ideas within the equivalent scope should be construed as being included in the scope of rights of the present invention.

10: LIDAR device
20: object
100: light source
200: scanning unit
210: Transmission member
230: Absence of reception
240: reflection part
250: driving unit
300: light detector
400: signal processing unit
500: optical window
700: Display unit

Claims (13)

In the lidar device,
a light source emitting first light;
a light detector that detects a second light, which is light reflected by an object located on the scan area, among the first lights;
Receive the emitted first light and reflect it toward the scan area, receive the second light reflected from the object, control the angle at which the second light is incident on the photo detector to be constant, and control the second light to be constant. a scanning unit that transmits light toward the optical detector; and
It includes a signal processing unit that obtains distance information about the object using the detection result of the light detector,
The scanning unit may include a reflection unit configured to reflect the emitted first light toward the object, reflect the second light reflected from the object toward the light detector, and adjust a scan area; And a driving unit connected to the reflector to drive the reflector,
The reflection unit may include a first mirror unit that adjusts a vertical field of view (FOV) of the scan area; a second mirror unit that adjusts a horizontal field of view (FOV) of the scan area; And a third mirror unit that controls the angle at which the second light is incident on the photo detector to be constant using the tilt angle of the first mirror unit,
It further includes an optical window for transmitting the first light obtained from the scanning unit and reflected toward the scan area and the second light reflected from the object and obtained from the scanning unit,
The optical window may include a window unit transmitting first light obtained from the scanning unit and reflected toward the scan area and second light reflected from the object and obtained from the scanning unit; a frame portion providing a structure for fixing the window portion; and at least two light reflecting mirrors fixed to the frame to reflect the first light. delete delete According to paragraph 1,
The first mirror unit and the third mirror unit are MEMS (Micro Electro Mechanical Systems) mirrors,
The second mirror unit is a LiDAR device, characterized in that the polygon mirror. According to paragraph 4,
The signal processing unit,
A LiDAR device, characterized in that the scan area is adjusted by tilting and driving the MEMS mirror in the vertical direction using the driving unit and rotating the polygon mirror in the horizontal direction. delete delete According to paragraph 1,
The second mirror unit,
Characterized in that it includes at least three surfaces for reflecting the first light reflected from the first mirror unit toward the object and reflecting the second light reflected by the object towards the third mirror unit. This is a device. According to clause 8,
The at least two light reflecting mirrors,
a first reflective surface that reflects the first light reflected from one surface of the second mirror unit; and
A second reflective surface that reflects the first light reflected from the first reflective surface to the other surface of the second mirror unit,
The other surface of the second mirror unit reflects the first light reflected from the second reflection surface toward the third mirror unit. According to paragraph 1,
The at least two light reflecting mirrors,
a first reflection mirror located at the left edge of the frame unit; and
It includes a second reflection mirror located at the right edge of the frame portion,
The signal processing unit,
When the second mirror unit rotates within a predetermined first driving range, the driving angle of the third mirror unit is controlled using the first reflection mirror,
A lidar device characterized in that when the second mirror unit rotates to a predetermined second driving range, the driving angle of the third mirror unit is controlled using the second reflection mirror. According to clause 10,
The signal processing unit,
When the first light in the scan area is irradiated to the left of the first scan area corresponding to one side based on the center of the optical window, the first light is transmitted to the photo detector using the first reflection mirror. Obtaining a first angle, which is the tilt angle of the third mirror unit to cause incident light,
When the first light in the scan area is irradiated to the right beyond the second scan area corresponding to the other side opposite to the one side based on the center of the optical window, the first light is emitted using the second reflection mirror. Obtaining a second angle, which is a tilt angle of the third mirror unit to make it incident on the photo detector,
A lidar device characterized in that the third mirror unit is controlled to be tilted within a range between the first angle and the second angle. According to paragraph 1,
The scanning unit,
a transmitting member that adjusts the first light incident from the light source to become parallel light; and
It includes a receiving member that condenses the second light and makes it incident on the light detector,
The photo detector is a lidar device characterized in that it is composed of an InGaAs-based PIN type, APD type, or SPAD type. In a method of operating a LiDAR device performed in a LiDAR device including a light source, a light detector, a scanning unit, and a signal processing unit,
the light source emitting first light;
The scanning unit receives the emitted first light and reflects it toward the scan area, receives the second light reflected from the object located on the scan area, and the angle at which the second light is incident on the photo detector. controlling to be constant and transmitting the second light toward the photo detector;
detecting, by the light detector, a second light that is light reflected by the object among the first light; and
A step of the signal processing unit acquiring distance information about the object using a detection result of the light detector,
The scanning unit may include a reflection unit configured to reflect the emitted first light toward the object, reflect the second light reflected from the object toward the light detector, and adjust a scan area; And a driving unit connected to the reflector to drive the reflector,
The reflection unit may include a first mirror unit that adjusts a vertical field of view (FOV) of the scan area; a second mirror unit that adjusts a horizontal field of view (FOV) of the scan area; And a third mirror unit that controls the angle at which the second light is incident on the photo detector to be constant using the tilt angle of the first mirror unit,
It further includes an optical window for transmitting the first light obtained from the scanning unit and reflected toward the scan area and the second light reflected from the object and obtained from the scanning unit,
The optical window may include a window unit transmitting first light obtained from the scanning unit and reflected toward the scan area and second light reflected from the object and obtained from the scanning unit; a frame portion providing a structure for fixing the window portion; and at least two light reflection mirrors fixed to the frame to reflect the first light.

Images