FMCW lidar-based multi-channel generation method, FMCW lidar to which same generation method is applied, and autonomous vehicle driving method using FMCW lidar to which same generation method is applied

Abstract

An FMCW LiDAR-based multi-channel generation method according to a first aspect of the present invention comprises the steps of: receiving an optical signal input from a laser diode (LD); splitting the input optical signal into multiple optical signals respectively corresponding to multiple channels; amplifying the multiple split optical signals; and steering each of the amplified optical signals on the basis of information of each of the amplified optical signals.

Description

A multi-channel generation method based on FMCW lidar, an FMCW lidar to which the generation method is applied, and a vehicle autonomous driving method using an FMCW lidar to which the generation method is applied.

[0001] The present invention relates to a multi-channel generation method based on FMCW lidar, an FMCW lidar to which the generation method is applied, and a vehicle autonomous driving method using an FMCW lidar to which the generation method is applied. This research was conducted with the support of the Korea Institute for Advancement of Technology (KIAT) with funds from the Ministry of Trade, Industry and Energy (Government) (Project Identification Number: 2410008035; Project Number: P0025240; Research and Development Project: International Joint Technology Development Project; Research Project Name: Multi-channel (200,000 channels) parallel processing solid-state FMCW technology-based lidar for vehicles; Project Period: January 1, 2024 - December 31, 2024).

[0002] For reference, this application claims priority to Korean Patent Application No. 10-2024-0091568, filed July 11, 2024. The entire contents of that application, which serves as the basis for this priority claim, are incorporated herein by reference.

[0003] LiDAR (light detection and ranging) is a sensor that transmits near-infrared light, visible light, and ultraviolet light to a target object, and detects the light that hits the target, reflects, and returns using an optical sensor to collect three-dimensional information (x, y, z) of the target object.

[0004] Typically, lidar uses light of a fixed frequency and can measure the time it takes for it to reflect back and the intensity of the light.

[0005] FMCW (frequency modulated continuous wave) lidar is similar to a general lidar that collects 3D information about the surrounding environment in terms of the way it transmits and receives light, but it differs from a general lidar in that it modulates the frequency of the light it transmits.

[0006] Since FMCW lidar emits light while rapidly changing its frequency, the emitted light can have a continuously changing frequency. When the emitted light hits an object or obstacle, some of the light may be reflected. The light reflected from the object or obstacle is collected by the FMCW lidar receiver, and the receiver can measure this frequency difference by comparing the frequency of the transmitted light with the frequency of the reflected light. If the object that hit the transmitted light is moving, a light with a frequency that has changed from the frequency of the transmitted light may be received depending on the degree of movement. Using the changed frequency, the relative velocity with the object caused by the Doppler effect can be calculated. In this way, FMCW lidar can measure the relative velocity value of a point in addition to the 3D information that a typical lidar can measure.

[0007] As shown in Fig. 1, the optical system of a typical conventional FMCW lidar includes a large number of laser diodes (LDs) in a single channel. Therefore, for multi-channel configuration, an LD array or multi-wavelength lasers must be used, which can lead to problems such as difficulty in controlling each LD and a large optical system.

[0008] When configuring an optical system using an LD array for multi-channel configuration, the price of the FMCW lidar may increase due to the high cost of the LD. Furthermore, when configuring an optical system using multi-wavelength lasers for multi-channel configuration, each wavelength must be individually referenced and used as a reception signal, potentially complicating and increasing the complexity of the optical system configuration.

[0009] Additionally, in a multi-channel configuration, the optical system may become complex in order to steer the beam for each LD in the transmitting and receiving optical system and then receive and focus each beam again.

[0010] The problem to be solved by the present invention is to provide a multi-channel generation method based on an FMCW lidar that generates multiple channels by separating an optical signal through a single laser diode.

[0011] In addition, a method for autonomous driving a vehicle using FMCW lidar with a multi-channel generation method based on FMCW lidar is provided.

[0012] However, the problems to be solved by the present invention are not limited to those mentioned above, and other problems to be solved that are not mentioned can be clearly understood by a person having ordinary skill in the art to which the present invention pertains from the description below.

[0013] A multi-channel generation method based on FMCW lidar according to one embodiment of the first aspect of the present invention includes a step of receiving an optical signal from a laser diode (LD), a step of splitting the input optical signal into a plurality of optical signals each corresponding to a plurality of channels, a step of amplifying the plurality of separated optical signals, and a step of steering each of the amplified optical signals based on information of each of the amplified optical signals.

[0014] The method may further include a step of propagating the amplified plurality of optical signals using at least one of an optical circulator, a fiber array, an optical waveguide, and an optical phased array (OPA).

[0015] The information of each of the amplified optical signals may include at least one of position information of the optical signal, polarization state, and interval and phase between each waveguide corresponding to the plurality of channels.

[0016] The above position information can be expressed as a two-dimensional coordinate value in which the horizontal axis of the lens is expressed as the x-axis and the vertical axis as the y-axis. At this time, in the steering step, the output steering angle can be determined based on the y-axis coordinate value at which each of the amplified optical signals is incident, thereby steering each of the amplified optical signals.

[0017] The relationship between the above incident y-axis coordinate value and the above output steering angle is can be determined. At this time, Y is the y-axis coordinate value, f is the focal length of the lens, may be the above output steering angle.

[0018] The above lens may be at least one of a telecentric F-theta lens, a diffractive optical element lens (DOE lens), a micro lens array (MLA), and a meta lens.

[0019] In the amplifying step, the separated plurality of optical signals can be amplified using at least one of an erbium doped waveguide amplifier (EDWA) and a semiconductor optical amplifier (SOA).

[0020] The frequency of the above optical signal can be increased or decreased periodically.

[0021] The frequency of the above optical signal can vary continuously over time.

[0022] The method may further include a step of modulating the frequency of the optical signal to generate a modulated optical signal having a modulation frequency different from the frequency. At this time, in the separating step, the optical signal and the modulated optical signal may be separated into different channels.

[0023] The step of generating the above-described modulated optical signal may include a four wave mixing operation in which the frequency of the input optical signal is modulated while being propagated through an optical path including a ring modulator, thereby generating the above-described modulated optical signal.

[0024] A vehicle autonomous driving method using an FMCW multi-channel lidar according to another embodiment of the first aspect of the present invention includes the steps of transmitting a Tx signal from the FMCW multi-channel lidar, receiving a signal reflected by an object from the transmitted signal as an Rx signal, obtaining information on the object based on the Tx signal and the Rx signal, and controlling a driving direction and speed of the vehicle based on the information on the object.

[0025] An FMCW multi-channel lidar according to a second aspect of the present invention includes a light source that generates an optical signal, a beam splitter that splits an input optical signal into a plurality of optical signals each corresponding to a plurality of channels, a beam amplifier that amplifies the plurality of separated optical signals, and a lens that steers each of the amplified optical signals based on information of each of the amplified optical signals.

[0026] The above FMCW multi-channel lidar can transmit a Tx signal, receive a signal reflected by an object from the transmitted signal as an Rx signal, obtain information on the object based on the Tx signal and the Rx signal, and provide information for controlling the driving direction and speed of the vehicle based on the information on the object.

[0027] A non-transitory computer-readable recording medium storing computer-executable instructions according to a third aspect of the present invention, wherein the computer-executable instructions, when executed by a processor, cause the processor to perform a method including the steps of receiving an optical signal from a laser diode (LD), splitting the input optical signal into a plurality of optical signals each corresponding to a plurality of channels, amplifying the plurality of separated optical signals, and steering each of the amplified optical signals based on information of each of the amplified optical signals.

[0028] A computer program stored in a non-transitory computer-readable recording medium according to a fourth aspect of the present invention, wherein the computer program, when executed by a processor, includes instructions for causing the processor to perform a method including the steps of receiving an optical signal from a laser diode (LD), splitting the input optical signal into a plurality of optical signals each corresponding to a plurality of channels, amplifying the plurality of separated optical signals, and steering each of the amplified optical signals based on information of each of the amplified optical signals.

[0029] According to the present invention, by generating multiple channels by separating an optical signal through a single laser diode in an FMCW lidar, the price of a conventional FMCW lidar multi-channel optical system using an expensive LD array method can be reduced.

[0030] In addition, the FMCW lidar multi-channel optical system can be miniaturized and the multi-channel optical system can be efficiently controlled.

[0031] The effects that can be obtained from the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present disclosure pertains from the description below.

[0032] Figure 1 is an exemplary diagram showing a conventional FMCW lidar for implementing a multi-channel optical system.

[0033] FIG. 2 is an exemplary diagram showing one embodiment for performing a multi-channel generation method based on FMCW lidar according to the present invention.

[0034] Figure 3 is an exemplary diagram illustrating a telecentric F-theta lens applicable to the present invention.

[0035] FIG. 4 is an exemplary diagram showing a simulation image for a multi-channel generation method based on FMCW lidar according to the present invention.

[0036] Figure 5 is an example diagram for explaining how to calculate the effective focal length of a lens by considering the area and angle of an optical fiber array.

[0037] FIG. 6 is a cross-sectional view of one embodiment for performing a multi-channel generation method based on FMCW lidar according to the present invention.

[0038] Figure 7 is an exemplary diagram showing a beam splitter of the present invention.

[0039] Fig. 8 is an exemplary diagram showing a beam amplification stage of the present invention.

[0040] Fig. 9 is an exemplary diagram showing a beam emission unit of the present invention.

[0041] FIG. 10 is a block diagram showing an entire system that performs a multi-channel generation method based on FMCW lidar according to the present invention.

[0042] FIG. 11 is a flowchart exemplarily showing a multi-channel generation method based on FMCW lidar according to the first aspect of the present invention.

[0043] Fig. 12 is a block diagram exemplarily showing an FMCW multi-channel lidar according to the second aspect of the present invention.

[0044] Figure 13 is a block diagram exemplifying the functions of an FMCW lidar-based multi-channel generation program.

[0045] The advantages and features of the present invention, and the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided solely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined solely by the scope of the claims.

[0046] When describing embodiments of the present invention, detailed descriptions of known functions or configurations will be omitted if they are deemed to unnecessarily obscure the gist of the invention. Furthermore, the terms described below are defined in light of their functions in the embodiments of the present invention and may vary depending on the intent or custom of the user or operator. Therefore, their definitions should be based on the overall content of this specification.

[0047] The terms used in this specification will be briefly explained, and the present invention will be described in detail.

[0048] The terms used in this specification have been selected from widely used, current terms, taking into account the functions of the present invention. However, these terms may vary depending on the intentions of those skilled in the art, precedents, the emergence of new technologies, etc. Furthermore, in certain cases, terms may be arbitrarily selected by the applicant, in which case their meanings will be described in detail in the relevant description of the invention. Therefore, the terms used in this invention should not be defined simply as names, but rather based on their inherent meanings and the overall content of the present invention.

[0049] When a part of a specification is said to 'include' a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise stated.

[0050] Also, the term 'part' used in the specification means a software or hardware component such as an FPGA or ASIC, and the 'part' performs certain functions. However, the 'part' is not limited to software or hardware. The 'part' may be configured to reside on an addressable storage medium or may be configured to play one or more processors. Thus, as an example, the 'part' includes components such as software components, object-oriented software components, class components, and task components, as well as processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided within the components and 'parts' may be combined into a smaller number of components and 'parts' or further separated into additional components and 'parts'.

[0051] Below, with reference to the attached drawings, an embodiment of the present invention is described in detail so that a person having ordinary skill in the art to which the present invention pertains can easily practice it.

[0052] FIG. 2 is an exemplary diagram showing one embodiment for performing a multi-channel generation method based on FMCW lidar according to the present invention, FIG. 7 is an exemplary diagram showing a beam splitter of the present invention, and FIG. 8 is an exemplary diagram showing a beam amplification stage of the present invention.

[0053] As shown in FIG. 2, the FMCW multi-channel lidar according to the present invention may include a laser diode (210), a beam splitter (220), a beam amplifier (230), and a lens (240).

[0054] A laser diode (210) can generate an optical signal having a predetermined frequency and provide it to a beam splitter (220). At this time, since the present invention is based on an FMCW lidar, the frequency of the optical signal can continuously change over time.

[0055] The beam splitter (220) can split the optical signal input from the laser diode (210) as shown in FIG. 7. That is, the beam splitter (220) can separate the input optical signal and divide it into channels. At this time, as the optical signal is separated, the intensity of the input optical signal may be weakened based on the number of channels. Accordingly, a beam amplification stage (230) may be required to increase the intensity of the optical signal.

[0056] The beam amplification stage (230) can amplify the separated optical signal as shown in Fig. 8. For example, the beam amplification stage (230) can be at least one of an erbium doped waveguide amplifier (EDWA) and a semiconductor optical amplifier (SOA).

[0057] The lens (240) can steer the amplified optical signal. The lens (240) can steer the amplified optical signal based on at least one of the position information of the optical signal, the polarization state, the spacing between each waveguide, and the phase. For example, the lens (240) can be at least one of a telecentric F-theta lens, a diffractive optical element lens (DOE lens), a micro lens array (MLA), and a meta lens. The DOE lens refers to a lens designed as a single structure by applying a micro pattern so as to change and control the phase of light and using the diffraction of light as a basic operating principle. The DOE lens does not require the use of multiple lenses as in the past. When a plane light is incident on the grid at the center of the DOE lens (incident wave), a wavefront is drawn by the diffraction zone, and a diffracted wave can be formed. Additionally, a micro lens array (MLA) may refer to a plurality of micro lenses arranged in a specific arrangement. A detailed description of a telecentric F-theta lens is provided in Fig. 3.

[0058] The lens (240) can steer the optical signal based on the position, phase, etc. of each divided optical signal without separate mechanical scanning. In addition, when receiving a signal reflected from an external object, the position at which the optical signal is received can vary depending on the position, phase, etc. of the received optical signal.

[0059] Figure 3 is an exemplary diagram illustrating a telecentric F-theta lens applicable to the present invention.

[0060] First, when using a standard lens, as shown in Figure 3(a), field curvature may exist, where the focus is formed on a spherical surface, depending on the angle of incidence of light. In this case, the focus may not be correct in areas other than the center.

[0061] To improve this, a flat field lens can be applied as shown in Fig. 3(b) to configure the focus to be on one surface regardless of the angle of incidence. However, if the length of the surface is (where y is the height (distance scanned), f is the focal length, Since the relationship is a function of the angle of investigation, a problem may arise where the distance (y) for scanning the optical signal increases nonlinearly.

[0062] Figure 3(c) is intended to improve the disadvantages of applying a flat field lens, and the length of the surface is Since the relationship is , the distance (y) for scanning the light signal can increase linearly. However, a problem may occur where the light does not enter vertically.

[0063] Figure 3(d) is a telecentric F-theta lens, with a surface length of The distance (y) at which the optical signal is scanned increases linearly, and light can be received vertically.

[0064] FIG. 4 is an exemplary diagram showing a simulation image for a multi-channel generation method based on FMCW lidar according to the present invention.

[0065] Assuming that a beam is steered using a telecentric F-theta lens, the positions of the split beams may differ when the beam is split. In this case, since the telecentric F-theta lens steers the beam according to the position of the incident beam, the positions of the beams output through the lens may also differ, as shown in the following mathematical equation.

[0066]

[0067] Here, y is the beam exit position (unit: mm), f is the effective focal length (unit: mm), refers to the angle (in radians) of the beam output relative to the axis for the effective focal length. Here, f is a value specific to the lens, so the lens can steer the beam by the y value (the exit position of the beam).

[0068] Figure 5 is an example diagram for explaining how to calculate the effective focal length of a lens by considering the area and angle of an optical fiber array.

[0069] Assuming that the lens in Fig. 5 is a 30-degree telecentric F-theta lens, Y is the radius of the lens, the number of channels is A, and the diameter of the optical fiber is Bum, the total area along the y-axis is can be calculated as . Also, if you convert 15 degrees to radians, am.

[0070] Next, by substituting the values ​​described above into mathematical expression 1, , can be calculated. Using this method, the effective focal length (EFL) f can be calculated and a lens can be designed.

[0071] FIG. 6 is a cross-sectional view of one embodiment for performing a multi-channel generation method based on FMCW lidar according to the present invention.

[0072] As shown in FIG. 6, one embodiment for performing the FMCW lidar-based multi-channel generation method according to the present invention may include a laser diode (210), a beam splitter (220), a beam amplifier (230), a beam output unit (231), and a lens (240).

[0073] Descriptions of the laser diode (210), beam splitter (220), beam amplifier (230), and beam lens (240) are the same as those of Fig. 2, so they will be omitted.

[0074] The beam emitter (231) can transmit a plurality of amplified optical signals to the lens (240) as shown in FIG. 9. For example, the beam emitter (231) can be at least one of an optical circulator, an optical fiber array, an optical waveguide, and an optical phased array (OPA). Depending on the configuration of the beam emitter (231), light can be emitted in various forms as shown in (a), (b), and (c) of FIG. 9.

[0075] The optical signal amplified through the beam amplifier (230) can be directly emitted, but can also be emitted through the beam emitter (231) as shown in FIGS. 6 and 9.

[0076] FIG. 10 is a block diagram showing an entire system that performs a multi-channel generation method based on FMCW lidar according to the present invention.

[0077] As shown in FIG. 10, the FMCW multi-channel lidar according to the present invention may include a laser diode (1210), a beam splitter (1220), a beam amplifier (1230), a light emitting unit (1240), a lens (1250), an interferometer (1270), and a photodiode (PD).

[0078] Here, among the contents of the laser diode (1210), beam splitter (1220), beam amplification stage (1230), light emitting unit (1240), and lens (1250), the same contents as the laser diode (210), beam splitter (220), beam amplification stage (230), light emitting unit (231), and lens (240) of FIGS. 2 and 6 will be omitted for explanation.

[0079] The FMCW multi-channel lidar according to the present invention can transmit an optical signal generated by a laser diode (1210) and receive a reflected light that is reflected from an object (1260) when the transmitted light is reflected. The FMCW multi-channel lidar can measure the time it takes for the transmitted light to be reflected and return and the intensity of the reflected light by analyzing the reflected light using an interferometer (1270). The FMCW multi-channel lidar can transmit light while changing its frequency. Accordingly, it can transmit light having a frequency that changes continuously. The light reflected from an object or obstacle can be received through a lens (1250), a light emission unit (1240), an interferometer (1270), and a photodiode (1280). The FMCW multi-channel lidar can measure the frequency difference by comparing the frequency of the transmitted light and the frequency of the reflected light.

[0080] Fig. 11 is a flowchart exemplifying a multi-channel generation method based on an FMCW lidar according to a first aspect of the present invention. Hereinafter, the multi-channel generation method based on an FMCW lidar will be described on the assumption that it is performed by an FMCW multi-channel lidar.

[0081] As shown in FIG. 11, the FMCW lidar-based multi-channel generation method according to the first aspect of the present invention includes a step of receiving an optical signal from a laser diode (LD) (S1110), a step of splitting the input optical signal into a plurality of optical signals each corresponding to a plurality of channels (S1120), a step of amplifying the plurality of separated optical signals (S1130), and a step of steering each of the amplified optical signals based on information of each of the amplified optical signals (S1140).

[0082] Fig. 12 is a block diagram exemplarily showing an FMCW multi-channel lidar according to the second aspect of the present invention.

[0083] As shown in FIG. 12, the FMCW multi-channel lidar (1200) may include an input unit (1210), an output unit (1220), a processor (1230), a memory (1240), and a communication unit (1260).

[0084] Hereinafter, for the convenience of explanation, an example is provided in which an FMCW multi-channel lidar (1200) includes an input unit (1210), an output unit (1220), a processor (1230), a memory (1240), and a communication unit (1260), but the present invention is not limited thereto. That is, each unit configuration may be provided outside the FMCW multi-channel lidar (1200) and may operate in a manner that interacts with the FMCW multi-channel lidar (1200).

[0085] The input unit (1210) may include a user interface for receiving commands, information, etc. used to control the FMCW multi-channel lidar (1200). In addition, the input unit (1210) may be a hardware device (e.g., a keyboard, a touch pad, a voice recognition microphone, etc.) that can directly receive commands, information, etc. used to control the FMCW multi-channel lidar (1200).

[0086] The input unit (1210) may include a light receiving module capable of receiving a reflected light reflected from an object from a transmitted light.

[0087] In one embodiment, the input unit (1210) can receive information required for the FMCW lidar-based multi-channel generation method from a user.

[0088] The output unit (1220) may include a light transmission module that transmits light whose frequency is modulated around the FMCW multi-channel lidar (1200).

[0089] The output unit (1220) can provide information related to an object, such as information appearing during the FMCW multi-channel lidar generation process, information about the generation result, object location information, and relative velocity, to the user as visual information through an interface or display device.

[0090] The processor (1230) can control the overall operation of the FMCW multi-channel lidar (1200) to perform the present invention.

[0091] The processor (1230) can load the FMCW lidar-based multi-channel generation program (1250) and information necessary for executing the FMCW lidar-based multi-channel generation program (1250) from the memory (1240) to execute the FMCW lidar-based multi-channel generation program (1250).

[0092] The processor (1230) can control to store data received from an external device through the communication unit (1260) in the memory (1240). In addition, the processor (1230) can control to transmit information related to an object, such as information appearing during the FMCW multi-channel lidar generation process, information about the generation result, object position information, and relative velocity, to the external device through the communication unit (1260).

[0093] The processor (1230) may refer to a processing device such as a microprocessor, a central processing unit (CPU), a graphic processing unit (GPU), a processor core, a multiprocessor, an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or a micro controller unit (MCU), but is not limited to the above-described embodiment.

[0094] The memory (1240) can store information required for executing the FMCW lidar-based multi-channel generation program (1250) and the FMCW lidar-based multi-channel generation program (1250). In addition, the memory (1240) can also store the processing results by the processor (1230).

[0095] The FMCW lidar-based multi-channel generation program (1250) may mean software including commands programmed to perform the method according to the present invention.

[0096] The memory (1240) can store information related to an object, such as information generated during the FMCW multi-channel lidar generation process, information on the generation result, object location information, and relative velocity. In addition, the memory (1240) can store information received from an external device via the communication unit (1260).

[0097] Memory (1240) may refer to a computer-readable recording medium, such as a magnetic media such as a hard disk, a floppy disk, and a magnetic tape, an optical media such as a CD-ROM, a DVD, a magneto-optical media such as a floptical disk, a random access memory such as a dynamic random access memory (DRAM) and a static random access memory (SRAM), and a hardware device specifically configured to store and execute program instructions such as a flash memory, but is not limited to the above-described embodiment.

[0098] The communication unit (1260) may be a wireless communication module capable of performing wireless communication by adopting a communication method such as CDMA, GSM, W-CDMA, TD-SCDMA, WiBro, LTE, EPC, 5G, wireless LAN, Wi-Fi, Bluetooth, Zigbee, WFD (Wi-Fi Direct), UWB (Ultra Wide Band), infrared communication (IrDA; infrared data association), BLE (Bluetooth Low Energy), or NFC (Near Field Communication), but is not limited to the above-described embodiment.

[0099] Additionally, information input and output through the input unit (1210) and output unit (1220), information stored in the memory (1240), and information transmitted and received through the communication unit (1260) include all information related to the present invention, and are not limited to the above-described embodiment.

[0100] The functions or operations of the FMCW lidar-based multi-channel generation program (1250) will be examined in detail with reference to Fig. 13.

[0101] Figure 13 is a block diagram exemplifying the functions of an FMCW lidar-based multi-channel generation program.

[0102] As shown in Fig. 13, the FMCW lidar-based multi-channel generation program (1250) may include an input unit (1310), a modulation unit (1320), a separation unit (1330), an amplifier unit (1340), a propagation unit (1350), and a steering unit (1360). The input unit (1310), the modulation unit (1320), the separation unit (1330), the amplifier unit (1340), the propagation unit (1350), and the steering unit (1360) are exemplary divisions of the functions of the FMCW lidar-based multi-channel generation program (1250), but are not limited thereto.

[0103] According to an embodiment, the functions of the input unit (1310), modulation unit (1320), separation unit (1330), amplifier unit (1340), propagation unit (1350), and steering unit (1360) can be merged / separated, and implemented as a series of commands included in at least one program.

[0104] The input unit (1310), modulation unit (1320), separation unit (1330), amplifier unit (1340), propagation unit (1350), and steering unit (1360) may be implemented by a processor (1230), and may mean a data processing device built into hardware having a physically structured circuit to perform a function expressed by a code or command included in an FMCW lidar-based multi-channel generation program (1250) stored in a memory (1240).

[0105] The input unit (1310) can receive an optical signal from a laser diode (LD).

[0106] The separation unit (1330) can separate (split) the input optical signal into multiple optical signals each corresponding to a plurality of channels.

[0107] The frequency of an optical signal can be periodically increased or decreased. Furthermore, the frequency of an optical signal can continuously change over time. The modulation unit (1320) can modulate the frequency of the optical signal to generate a modulated optical signal having a modulation frequency different from the frequency. Here, the separation unit (1330) can separate the optical signal and the modulated optical signal into different channels.

[0108] The modulation unit (1320) may include a modulator. Specifically, by inputting the outputs of two laser diodes (LD1, LD2) having two different frequencies into the modulator, two new lasers having frequencies different from the input frequencies may be generated. Here, the modulator may be configured to implement four-wave mixing. For example, the modulator may be configured in the form of a micro-ring modulator. In this case, the length of the micro-ring modulator may be determined in consideration of the wavelength of the output laser.

[0109] The amplifier (1340) can amplify a plurality of separated optical signals. For example, the amplifier (1340) can amplify a plurality of separated optical signals using at least one of an erbium doped waveguide amplifier (EDWA) and a semiconductor optical amplifier (SOA).

[0110] The propagation unit (1350) can propagate a plurality of optical signals amplified by the amplifier unit (1340). For example, the propagation unit (1350) can be at least one of an optical circulator, an optical fiber array, an optical waveguide, and an optical phased array (OPA).

[0111] The steering unit (1360) can steer each amplified optical signal based on information of each amplified optical signal.

[0112] The information of each amplified optical signal may include at least one of position information of the optical signal, polarization state, spacing between waveguides corresponding to multiple channels, and phase.

[0113] Here, the position information can be expressed as a two-dimensional coordinate value in which the horizontal axis of the lens is expressed as the x-axis and the vertical axis as the y-axis. Accordingly, the steering unit (1360) can steer each amplified optical signal by determining an output steering angle based on the y-axis coordinate value at which each amplified optical signal is incident. Here, the lens can be at least one of a telecentric F-theta lens, a diffractive optical element lens (DOE lens), a micro lens array (MLA), and a meta lens.

[0114] The relationship between the input y-axis coordinate value and the output steering angle is can be determined. Here, Y can be the y-axis coordinate value, f can be the focal length of the lens, and θ can be the output steering angle.

[0115] As described above, according to the present invention, by generating multiple channels by separating an optical signal through a single laser diode in an FMCW lidar, the price of a conventional FMCW lidar multi-channel optical system using an expensive LD array method can be reduced.

[0116] In addition, the FMCW lidar multi-channel optical system can be miniaturized and the multi-channel optical system can be efficiently controlled.

[0117] The embodiments of the present invention described above may be implemented through various means. For example, the embodiments of the present invention may be implemented using hardware, firmware, software, or a combination thereof.

[0118] The combination of each block of the block diagram and each step of the flowchart attached to the present invention may be performed by computer program instructions. These computer program instructions may be installed in an encoding processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the encoding processor of the computer or other programmable data processing equipment create a means for performing the functions described in each block of the block diagram or each step of the flowchart. These computer program instructions may also be stored in a computer-available or computer-readable memory that can direct a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce an article of manufacture that includes an instruction means for performing the functions described in each block of the block diagram or each step of the flowchart. Since the computer program instructions can also be installed on a computer or other programmable data processing device, a series of operational steps are performed on the computer or other programmable data processing device to create a computer-executable process, and the instructions that cause the computer or other programmable data processing device to perform the steps for executing the functions described in each block of the block diagram and each step of the flowchart can also provide steps for executing the functions described in each block of the block diagram and each step of the flowchart.

[0119] Additionally, each block or step may represent a module, segment, or portion of code that includes one or more executable instructions for performing a specific logical function(s). In some embodiments, the functions mentioned in the blocks or steps may occur out of order. For example, two blocks or steps depicted in succession may actually be performed substantially simultaneously, or the blocks or steps may sometimes be performed in reverse order depending on the corresponding function.

[0120] The above description is merely an illustrative illustration of the technical idea of ​​the present invention, and those skilled in the art will appreciate that various modifications and variations can be made without departing from the essential quality of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate, rather than limit, the technical idea of ​​the present invention, and the scope of the technical idea of ​​the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within a scope equivalent thereto should be interpreted as being included in the scope of the rights of the present invention.

Claims

1. In a multi-channel generation method based on FMCW lidar, the method is performed by an FMCW (frequency modulated continuous wave) lidar including multiple channels, A step of receiving an optical signal from a laser diode (LD); A step of splitting an input optical signal into a plurality of optical signals each corresponding to a plurality of channels; a step of amplifying the above separated plurality of optical signals; and A step of steering each amplified optical signal based on information of each amplified optical signal, A multi-channel generation method based on FMCW lidar.

2. In paragraph 1, Further comprising a step of propagating the amplified plurality of optical signals using at least one of an optical circulator, a fiber array, an optical waveguide, and an optical phased array (OPA). A multi-channel generation method based on FMCW lidar.

3. In paragraph 1, The information of each of the amplified optical signals includes at least one of position information of the optical signal, polarization state, and interval and phase between each waveguide corresponding to the plurality of channels. A multi-channel generation method based on FMCW lidar.

4. In paragraph 3, The above location information is expressed as a two-dimensional coordinate value in which the horizontal axis of the lens is expressed as the x-axis and the vertical axis is expressed as the y-axis. In the above steering step, The amplified optical signal is steered by determining an output steering angle based on the y-axis coordinate value at which the amplified optical signal is incident. A multi-channel generation method based on FMCW lidar.

5. In paragraph 4, The relationship between the above incident y-axis coordinate value and the above output steering angle is is determined, and at this time, Y is the y-axis coordinate value, f is the focal length of the lens, is the output steering angle, A multi-channel generation method based on FMCW lidar.

6. In paragraph 4, The above lens is at least one of a telecentric F-theta lens, a diffractive optical element lens (DOE lens), a micro lens array (MLA), and a meta lens. A multi-channel generation method based on FMCW lidar.

7. In paragraph 1, In the above amplifying step, Amplifying the separated plurality of optical signals using at least one of an erbium doped waveguide amplifier (EDWA) and a semiconductor optical amplifier (SOA). A multi-channel generation method based on FMCW lidar.

8. In paragraph 1, The frequency of the above optical signal increases and decreases periodically. A multi-channel generation method based on FMCW lidar.

9. In paragraph 8, The frequency of the above optical signal changes continuously over time. A multi-channel generation method based on FMCW lidar.

10. In paragraph 9, Further comprising a step of modulating the frequency of the optical signal to generate a modulated optical signal having a modulation frequency different from the frequency, In the above separation step, Separating the optical signal and the modulated optical signal into different channels, A multi-channel generation method based on FMCW lidar.

11. In paragraph 10, The step of generating the above modulated optical signal is: Including a four wave mixing operation in which the frequency of the input optical signal is modulated while being propagated through an optical path including a ring modulator to generate the modulated optical signal. A multi-channel generation method based on FMCW lidar.

12. A light source that generates an optical signal; A beam splitter that splits an input optical signal into multiple optical signals each corresponding to a plurality of channels; A beam amplifier stage for amplifying the above-described plurality of separated optical signals; A lens that steers each amplified optical signal based on information of each amplified optical signal, FMCW multi-channel lidar.

13. In paragraph 12, The above FMCW multi-channel lidar is, Propagating the amplified plurality of optical signals using at least one of an optical circulator, a fiber array, an optical waveguide, and an optical phased array (OPA). FMCW multi-channel lidar.

14. In paragraph 12, The information of each amplified optical signal is including at least one of position information of the optical signal, polarization state, spacing between waveguides corresponding to the plurality of channels, and phase; FMCW multi-channel lidar.

15. In paragraph 14, The above location information is expressed as a two-dimensional coordinate value in which the horizontal axis of the lens is expressed as the x-axis and the vertical axis is expressed as the y-axis. The above lens, The amplified optical signal is steered by determining an output steering angle based on the y-axis coordinate value at which the amplified optical signal is incident. FMCW multi-channel lidar.

16. In paragraph 15, The relationship between the above incident y-axis coordinate value and the above output steering angle is is determined, and at this time, Y is the y-axis coordinate value, f is the focal length of the lens, is the output steering angle, FMCW multi-channel lidar.

17. In paragraph 15, The above lens, At least one of a telecentric F-theta lens, a diffractive optical element lens (DOE lens), a micro lens array (MLA), and a meta lens, FMCW multi-channel lidar.

18. In paragraph 12, The above beam amplification stage is, Amplifying the separated plurality of optical signals using at least one of an erbium doped waveguide amplifier (EDWA) and a semiconductor optical amplifier (SOA). FMCW multi-channel lidar.

19. In paragraph 12, The above FMCW multi-channel lidar is, Transmit the Tx signal, Receive the reflected signal from the object of the transmitted signal as an Rx signal, Obtain information about the object based on the Tx signal and the Rx signal, Providing information for controlling the driving direction and speed of the vehicle based on the information of the above object. FMCW multi-channel lidar.

20. A non-transitory computer-readable recording medium storing computer-executable instructions, wherein the computer-executable instructions, when executed by a processor, A step of receiving an optical signal from a laser diode (LD); A step of splitting an input optical signal into multiple optical signals each corresponding to a plurality of channels; a step of amplifying the above separated plurality of optical signals; and A method for causing the processor to perform a method including a step of steering each of the amplified optical signals based on information of each of the amplified optical signals, Non-transitory computer-readable recording medium.

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