LiDAR device using intermittent continuous wave light

Abstract

A light detection and ranging (LiDAR) device capable of extracting velocity information and distance information of a front object is provided. The LiDAR device includes a continuous wave light source configured to generate continuous wave light, a beam steering apparatus configured to emit the continuous wave light toward the object during a first time and to stop emitting the continuous wave light toward the object during a second time, a receiver configured to receive the continuous wave light reflected from the object to form a received signal, and a signal processor configured to obtain distance information and velocity information about the object based on the received signal.

Description

TECHNICAL FIELD

[0001] Apparatuses and methods consistent with exemplary embodiments relate to a light detection and ranging (LiDAR) apparatus, and more particularly, to a LiDAR apparatus capable of extracting velocity information and distance information of a front object by using an intermittent continuous wave light. BACKGROUND

[0002] Recently, an advanced driver assistance system (ADAS) having various functions has been commercialized. For example, more and more vehicles are equipped with functions such as adaptive cruise control (ACC) or autonomous emergency braking system (AEB). The function of ACC is to recognize the position and speed of other vehicles to reduce the speed when there is a risk of collision and to drive the vehicle within a set speed range when there is no risk of collision. AEB is a system that prevents a collision by automatically braking when a front vehicle is recognized but the driver does not respond or the response method is inappropriate. In addition, it is predictable that a car capable of autonomous driving will be commercialized in the near future.

[0003] Accordingly, the importance of a vehicle radar for providing information in front of a vehicle is gradually increasing. For example, a LiDAR sensor is generally used as a vehicle radar to measure the distance, speed, azimuthal position, etc. of a measurement target from the time when a scattered or reflected laser light, a laser light intensity change, a laser light frequency change, a polarization state change of a laser light, etc. returns after emitting a laser light.

[0004] LiDAR sensors are classified into a time-of-flight (ToF) type sensor using a pulse and a frequency-modulated continuous wave (FMCW) type sensor using a continuous wave light. In the case of the ToF type sensor using a pulse, since the pulse includes a wide frequency band, a wideband receiver can be required. This makes it difficult to suppress noise. On the other hand, in the case of the FMCW type sensor using a continuous wave light, although a narrowband receiver can be used to suppress noise, the FMCW type sensor can use a high-power continuous wave light source that is difficult to implement and expensive. SUMMARY

[0005] Exemplary embodiments address at least the above problems and / or disadvantages and other disadvantages not described above. Also, the exemplary embodiments do not require overcoming of the above disadvantages and can not overcome any of the problems described above.

[0006] One or more exemplary embodiments provide a light detection and ranging (LiDAR) apparatus capable of extracting velocity information and distance information of a front object by using an intermittent continuous wave light.

[0007] Furthermore, one or more exemplary embodiments provide a LiDAR apparatus capable of suppressing noise by using a narrowband receiver and capable of using a low-cost, low-power continuous wave light source.

[0008] According to one aspect of an exemplary embodiment, a light detection and ranging (LiDAR) device is provided, including: a continuous wave light source configured to generate continuous wave light; a beam steering device configured to emit continuous wave light to an object during a first time period and stop emitting continuous wave light to the object during a second time period; a receiver configured to receive the continuous wave light reflected from the object to form a received signal; and a signal processor configured to obtain distance information and speed information about the object based on the received signal.

[0009] The beam steering device may also be configured to periodically repeat an operation of emitting continuous wave light during the first time and an operation of stopping emitting continuous wave light during the second time.

[0010] The second time may be greater than the first time.

[0011] The first time may be in the range of 1 ns to 1000 ns.

[0012] The LiDAR device may also include: a beam splitter configured to provide a first part of the continuous wave light generated by the continuous wave light source to the beam steering device, so that the first part of the continuous wave light is emitted to the object and reflected from the object, and then received by the receiver, and a second part of the continuous wave light is provided to the receiver, wherein the receiver may also be configured to form the received signal by combining the first part of the continuous wave light received by the receiver with the second part of the continuous wave light provided from the beam splitter, and causing the first part and the second part of the continuous wave light to interfere with each other.

[0013] The LiDAR device may further include: an optical amplifier configured to amplify the continuous wave light generated by the continuous wave light source and provide the amplified continuous wave light to the beam steering device during the first time, and stop amplifying and outputting the continuous wave light during the second time.

[0014] The light beam steering device may also be configured to: emit continuous wave light multiple times toward a first area in front of the light beam steering device, and then emit continuous wave light multiple times toward a second area different from the first area.

[0015] The signal processor may also be configured to: accumulate a plurality of first received signals received from the first area, and obtain distance information and speed information about a first object in the first area based on the accumulated plurality of first received signals; and accumulate a plurality of second received signals received from the second area, and obtain distance information and speed information about a second object in the second area based on the accumulated plurality of second received signals.

[0016] The LiDAR device may further include: a frequency modulator configured to drive the continuous wave light source so that the continuous wave light source generates frequency modulated continuous wave light, wherein the beam steering device may further be configured to: emit the frequency modulated continuous wave light toward the object during the first time period, and stop emitting the frequency modulated continuous wave light toward the object during the second time period.

[0017] The signal processor may be further configured to obtain distance information and speed information about the object by analyzing a frequency of the received signal in a frequency modulated continuous wave (FMCW) manner.

[0018] The frequency modulator may be configured to linearly increase the frequency of the frequency modulated continuous wave light during a third time.

[0019] The third time may be equal to the sum of the first time and the second time, and the beam steering device is further configured to emit the frequency modulated continuous wave light once during the third time.

[0020] The third time may be greater than the sum of the first time and the second time, and the beam steering device is further configured to emit the frequency-modulated continuous wave light multiple times during the third time.

[0021] The frequency modulator may also be configured to linearly increase the frequency of the frequency modulated continuous wave light during a third time and linearly decrease the frequency during a fourth time, wherein the third time for increasing the frequency of the frequency modulated continuous wave light and the fourth time for decreasing the frequency of the frequency modulated continuous wave light may be periodically repeated.

[0022] Each of the third time and the fourth time can be equal to the sum of the first time and the second time, and the beam steering device can also be configured to emit the frequency modulated continuous wave light once during the third time and once during the fourth time.

[0023] Each of the third time and the fourth time can be greater than the sum of the first time and the second time, and the beam steering device can also be configured to emit the frequency modulated continuous wave light multiple times during the third time and emit the frequency modulated continuous wave light multiple times during the fourth time.

[0024] The signal processor may also be configured to obtain distance information and speed information about the object in an FMCW manner based on a received signal obtained from the reflected light of the frequency modulated continuous wave light emitted during the third time period and a received signal obtained from the reflected light of the frequency modulated continuous wave light emitted during the fourth time period.

[0025] The signal processor may be further configured to obtain distance information about the object by analyzing a waveform of the received signal in a time-of-flight (ToF) manner.

[0026] The signal processor may be further configured to adjust the distance information about the object based on the distance information extracted in the ToF manner and the distance information extracted in the FMCW manner.

[0027] The signal processor may be further configured to extract distance information about the object by analyzing a waveform of the received signal in a TOF manner, and obtain speed information about the object by analyzing a frequency of the received signal in a Doppler manner.

[0028] According to one aspect of an exemplary embodiment, a method for sensing an object by a light detection and ranging (LiDAR) device is provided, the method including: generating continuous wave light; dividing the continuous wave light into a first part and a second part; amplifying the first part of the continuous wave light; intermittently emitting the amplified first part of the continuous wave light toward an object, the amplified first part of the continuous wave light being reflected from the object and received by a receiver of the LiDAR device; providing the second part of the continuous wave light to the receiver; generating a received signal by combining the amplified first part of the continuous wave light and the second part of the continuous wave light received by the receiver; and obtaining distance information and speed information about the object based on the received signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and / or other aspects will become more apparent by describing certain exemplary embodiments with reference to the accompanying drawings, in which:

[0030] Figure 1 is a block diagram illustrating a schematic configuration of a light detection and ranging (LiDAR) apparatus according to an exemplary embodiment;

[0031] Figures 2A-2CAn example of a configuration and operation of an optical phased array for scanning a laser is shown;

[0032] Figure 3 is a timing diagram illustrating operation of a LiDAR device according to an example embodiment; Figure 1 is a timing diagram illustrating operation of a LiDAR device according to an example embodiment;

[0033] Figure 4 is a plot illustrating frequency components of transmitted light and frequency components of received light in a frequency modulated continuous wave (FMCW) method;

[0034] Figure 5 is a timing diagram illustrating operation of a LiDAR device according to another example embodiment; Figure 1 is a timing diagram illustrating operation of a LiDAR device according to another example embodiment;

[0035] Figure 6 is a timing diagram illustrating operation of a LiDAR device according to another example embodiment; Figure 1 is a plot illustrating frequency components of transmitted light and frequency components of received light in a triangular FMCW method;

[0036] Figure 7 is a plot illustrating frequency components of transmitted light and frequency components of received light in a triangular FMCW method;

[0037] Figure 8 is a timing diagram illustrating operation of a LiDAR device according to another example embodiment; Figure 1 is a timing diagram illustrating operation of a LiDAR device according to another example embodiment;

[0038] Figure 9 is a block diagram illustrating a schematic configuration of a LiDAR device according to another example embodiment; and

[0039] Figure 10 is a timing diagram illustrating operation of a LiDAR device according to an example embodiment; Figure 9 is a timing diagram illustrating operation of a LiDAR device according to an example embodiment. DETAILED DESCRIPTION

[0040] Example embodiments are described in greater detail below with reference to the accompanying drawings.

[0041] In the following description, the same drawing reference numerals are used for the same elements even in different drawings. The matters defined in the description such as detailed construction and elements are provided to assist in a comprehensive understanding of example embodiments. It is apparent that various modifications can be made to the example embodiments, without departing from the scope of the example embodiments. Additionally, well-known functions or constructions are not described in detail since they would obscure the example embodiments with unnecessary detail.

[0042] As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding the

[0043] Hereinafter, a light detection and ranging (LiDAR) apparatus using an intermittent continuous wave light will be described in detail with reference to the accompanying drawings. In the following drawings, like reference numerals refer to like elements throughout. Also, the size of each layer shown in the drawings can be exaggerated for the sake of convenience and clarity. Furthermore, the exemplary embodiments are described below by referring to the drawings, which are only for explaining aspects of the present specification, and the illustrated exemplary embodiments can have different forms. In the layer structure described below, when a constituent element is arranged “above” or “over” another constituent element, the constituent element can include not only an element directly contacting the upper / lower / left / right side of the other constituent element, but also an element disposed in a non-contact manner on the upper / lower / left / right side of the other constituent element.

[0044] Figure 1 is a block diagram illustrating a schematic configuration of a LiDAR apparatus 100 according to an exemplary embodiment. Referring to Figure 1 The LiDAR apparatus 100 according to an exemplary embodiment can include a continuous wave light source 110 generating a continuous wave light, a frequency modulator 120 driving the continuous wave light source 110 so that the continuous wave light source 110 generates a frequency-modulated light, a beam steering device 130 emitting the frequency-modulated continuous wave light emitted from the continuous wave light source 110 to an external object (e.g., a vehicle) or steering the frequency-modulated continuous wave light toward the external object (e.g., a vehicle), a receiver 140 receiving light reflected from the external object and forming a reception signal, and a signal processor 150 configured to extract distance information and velocity information about the external object based on the reception signal formed by the receiver 140.

[0045] The continuous wave light source 110 is configured to continuously oscillate and emit a continuous wave light having a waveform such as a sine wave. Also, the continuous wave light source 110 can be configured to emit laser light in an infrared waveband that is invisible to the human eye. For example, the continuous wave light source 110 can be configured to emit laser light having a wavelength in the range of about 800 nm to about 2000 nm.

[0046] The frequency modulator 120 controls the driving of the continuous wave light source 110. The continuous wave light source 110 can be controlled by the frequency modulator 120 to generate frequency modulated continuous wave light. For example, the modulation frequency of the frequency modulator 120 can be about 10 kHz to about 10 MHz, and its modulation bandwidth can be about 100 MHz to about 10 GHz.

[0047] In addition, the LiDAR device 100 may further include an optical amplifier 125 and an optical amplifier controller 126. The optical amplifier 125 is configured to amplify the continuous wave light generated by the continuous wave light source 110 and provide the amplified continuous wave light to the beam steering device 130. The optical amplifier controller 126 is configured to control the operation of the optical amplifier 125 based on commands from the signal processor 150 to amplify the continuous wave light. For example, the optical amplifier controller 126 can control the on / off function, amplification gain, etc. of the optical amplifier 125. The optical amplifier 125 can be, for example, a high-power amplifier having a gain of approximately 5 dB to approximately 30 dB and a saturated output power of approximately 10 mW to approximately 1000 mW. By using the optical amplifier 125 as a high-power amplifier, a relatively low-cost low-power continuous wave laser can be used as the continuous wave light source 110.

[0048] The beam steering device 130 may include an optical phased array (OPA) device configured to scan the continuous wave light generated by the continuous wave light source 110 in one dimension or two dimensions. The beam steering device 130 can send the continuous wave laser light amplified by the optical amplifier 125 toward a local area in front in a one-dimensional (1D) or two-dimensional (2D) scanning manner. To this end, the beam steering device 130 can sequentially or non-sequentially steer the laser light focused in a narrow area to the one-dimensional or two-dimensional area in front at constant time intervals. For example, the beam steering device 130 can be configured to emit laser light from left to right or from right to left for the one-dimensional area in front, or to emit laser light from left to right or from right to left and from bottom to top or from top to bottom for the two-dimensional area in front.

[0049] For example, Figures 2A-2C An example of the configuration and operation of the beam steering device 130 for scanning laser light is shown. Figure 2A The beam steering device 130 may include a transmitting element array 133, which includes a plurality of transmitting elements 134 arranged two-dimensionally along a plurality of rows and a plurality of columns. The beam steering device 130 may also include a driving circuit for driving each transmitting element 134 in the transmitting element array 133. Each transmitting element 134 may be, for example, a reflective antenna resonator that delays the phase of incident light to reflect it, or a transmissive antenna resonator that delays the phase of incident light to transmit it. The phase of the reflected or transmitted laser light may be determined by a voltage applied to each transmitting element 134 under the control of the driving circuit.

[0050] In this configuration, the direction of laser light emitted from the transmission element array 133 can be controlled based on the phase difference between the multiple laser beams emitted from the multiple transmission elements 134. Specifically, the horizontal direction of the laser light can be controlled based on the phase difference ΔΦ1 between the multiple laser beams emitted from the multiple transmission elements 134 arranged along the same row. Furthermore, the vertical direction of the laser light can be controlled based on the phase difference ΔΦ2 between the multiple laser beams emitted from the multiple transmission elements 134 arranged along the same column.

[0051] For example, Figure 2A As shown, as the phase of the laser light gradually lags from the rightmost transmitting element 134 to the leftmost transmitting element 134 in the same row, the laser light travels leftward. The azimuthal angle of the laser light can be determined by the phase difference ΔΦ1 between the multiple laser beams emitted from two adjacent transmitting elements 134 in the same row. As the phase difference ΔΦ1 increases, the laser light tilts further to the left, while as the phase difference ΔΦ1 decreases, the laser light travels closer to the front.

[0052] Furthermore, when the phase of the laser light gradually lags from the top transmitting element 134 to the bottom transmitting element 134 in the same column, the laser light travels downward. In this case, the elevation angle of the laser light can be determined by the phase difference ΔΦ2 between the multiple laser beams emitted from two adjacent transmitting elements 134 in the same column. As the phase difference ΔΦ2 increases, the laser light tilts further downward, while as the phase difference ΔΦ2 decreases, the laser light travels closer to the front.

[0053] Reference Figure 2B , when the phase difference ΔΦ1 is 0 and the phase difference ΔΦ2 is 0, the laser light emitted from the transmitting element array 133 is completely guided to the front side. Figure 2C When the phase of the laser light is gradually delayed from the transmission element 134 at the left end to the transmission element 134 at the right end in the same row, the laser light travels rightward. When the phase of the laser light is gradually delayed from the transmission element 134 at the bottom to the transmission element 134 at the top in the same column, the laser light travels upward.

[0054] Therefore, by individually controlling the phases of the multiple laser beams emitted from the multiple transmitting elements 134 of the transmitting element array 133, the laser beams can be steered in a desired direction. The transmitting element array 133 can be configured to independently apply voltages to the multiple transmitting elements 134 under the control of a driver circuit. The phase of the laser beam emitted from each transmitting element 134 can be determined by the voltage applied to the transmitting element 134, and the direction of the laser beam emitted from the transmitting element array 133 can be determined by the combination of the voltages applied to the multiple transmitting elements 134.

[0055] In Figures 2A-2C In this case, the light beam steering device 130 can transmit the laser light in a one-dimensional (1D) scanning manner toward the front.

[0056] Hitherto, the light beam steering device 130 has been described as scanning the laser light by using an optical phased array method, but is not necessarily limited thereto. Instead of the optical phased array method, the light beam steering device 130 can scan the laser light by other scanning methods. For example, the light beam steering device 130 can include an actuator that rotates the continuous wave light source 110. In this case, the direction of the laser light can be adjusted by directly rotating the continuous wave light source 110. In another example, the light beam steering device 130 can include a mirror that reflects the laser light and an actuator that rotates the mirror, or can include a micro electro mechanical system (MEMS) device that controls the reflection direction of the laser light by electrically controlling fine tilting of the mirror.

[0057] The light transmitted from the light beam steering device 130 is reflected by an external object and returned to the LiDAR apparatus 100. The LiDAR apparatus 100 can receive the light reflected from the external object, generate an electrical reception signal from the light, and obtain information about the external object from the electrical reception signal. When receiving the light reflected from the external object to form the electrical reception signal, the frequency-modulated continuous wave light emitted from the continuous wave light source 110 can be divided, and a part of the frequency-modulated continuous wave light can be used as a local oscillator light to perform frequency analysis. To this end, the LiDAR apparatus 100 can further include a beam splitter 115 that divides the frequency-modulated continuous wave light emitted from the continuous wave light source 110 and provides a majority of the frequency-modulated continuous wave light to the light beam steering device 130 and the rest to the receiver 140. For example, the beam splitter 115 can be configured to provide at least 90% of the incident light to the light beam steering device 130 and the rest to the receiver 140 as the local oscillator light. In particular, the beam splitter 115 can be disposed on an optical path between the continuous wave light source 110 and the optical amplifier 125 to provide the optical amplifier 125 with a majority of the incident light incident from the continuous wave light source 110.

[0058] Receiver 140 is configured to form an electrical reception signal for interference light, where the interference light is obtained by interference between light reflected from an external object and local oscillator light provided from beam splitter 115. For example, receiver 140 may include a light receiving element 141 that receives the light reflected from the external object, a beam combiner 142 that combines the light received by light receiving element 141 with the local oscillator light provided from beam splitter 115 so that the received light and the local oscillator light interfere with each other, and a photodetector 143 that converts the intensity of the interference light into an electrical signal. Light receiving element 141 may include, for example, a lens or a lens array. Receiver 140 may also include a bandpass filter or a low-pass filter to remove noise components and obtain the interference light component. Receiver 140 may convert the interference light into an electrical signal via photodetector 143 to form the electrical reception signal. Because the interference light is in a relatively narrow frequency band, a relatively narrowband receiver can be used as receiver 140, compared to receivers used in pulsed LiDAR devices.

[0059] The signal processor 150 may extract distance information and speed information about an external object based on the received signal received from the receiver 140. In addition, the signal processor 150 may be configured to control the frequency modulator 120 to adjust the frequency modulation scheme, and control the beam steering device 130 to control the scanning operation. Figure 1 , the signal processor 150, the frequency modulator 120, and the receiver 140 are shown as separate blocks, but the signal processor 150, the frequency modulator 120, and the receiver 140 may be integrally implemented in a single semiconductor chip. Alternatively, the signal processor 150, the frequency modulator 120, and the receiver 140 may be formed on a single printed circuit board. Alternatively, the frequency modulator 120 and the receiver 140 may be integrally implemented as a single semiconductor chip, and the signal processor 150 may be implemented as software that can be executed in a computer and stored in a recording medium. According to another example, the signal processor 150 may be implemented as a programmable logic controller (PLC), a field programmable gate array (FPGA), or the like.

[0060] According to this exemplary embodiment, the optical amplifier 125 and the beam steering device 130 may be configured to intermittently (intermittently or discontinuously) amplify the frequency modulated continuous wave light and intermittently (intermittently or discontinuously) emit the amplified frequency modulated continuous wave light under the control of the signal processor 150. For example, Figure 3 is a diagram showing a method according to an exemplary embodiment Figure 1 The timing diagram of the operation of the LiDAR device 100 is shown. Figure 3 The beam steering device 130 may be configured to, under the control of the signal processor 150 , emit frequency modulated continuous wave light to the outside only during the first time T1 and not emit frequency modulated continuous wave light to the outside during the second time T2 .

[0061] To this end, signal processor 150 may activate optical amplifier 125 and beam steering device 130 during a first time T1 and stop the operation of optical amplifier 125 and beam steering device 130 during a second time T2. Then, during the second time T2, the optical output of optical amplifier 125 and beam steering device 130 is stopped, and thus, light is not emitted to the outside of LiDAR device 100. Even when the operation of beam steering device 130 is interrupted, continuous wave light source 110 and frequency modulator 120 continue to generate frequency-modulated continuous wave light without stopping operation, thereby continuously providing local oscillator light for forming a received signal to receiver 140.

[0062] The signal processor 150 can control the beam steering device 130 to periodically repeat a first time T1 for emitting continuous wave light and a second time T2 for not emitting continuous wave light. In this way, the LiDAR device 100 can sequentially emit multiple transmission light beams Tx1, Tx2, Tx3, ... . Each of the multiple transmission light beams Tx1, Tx2, Tx3, ... is similar to pulsed light in that it only lasts for the first time T1 and is interrupted and therefore not transmitted at the second time T2. However, each of the multiple transmission light beams Tx1, Tx2, Tx3, ... differs from conventional pulsed light in that it is frequency-modulated continuous wave light whose frequency varies over time. When dispersion is not considered, the frequency of conventional pulsed light remains constant over time.

[0063] The first time T1 during which each of the multiple transmitted light beams Tx1, Tx2, Tx3, ... continues, and the second time T2 during which each of the multiple transmitted light beams Tx1, Tx2, Tx3, ... is interrupted can be appropriately selected as needed. For example, the first time T1 and the second time T2 can be determined based on the time it takes for light emitted from the LiDAR device 100 to reflect from an external object and return to the LiDAR device 100, as well as the horizontal viewing angle, vertical viewing angle, horizontal scanning resolution, vertical scanning resolution, frame rate, etc. of the beam steering device 130. The first time T1 can be selected within a range of approximately 1 ns to approximately 1000 ns. In addition, when considering the time it takes to receive the multiple received light beams Rx1, Rx2, Rx3, ... that reflect from an external object and return to the LiDAR device 100, the second time T2 can be determined to be longer than the first time T1.

[0064] The receiver 140 receives each of the multiple beams of reception light Rx1, Rx2, Rx3,... reflected from external objects and returned, and generates an electric reception signal. As described above, the electric reception signal can be obtained from interference light generated by interference between local oscillator light for frequency analysis provided from the continuous wave light source 110 and each of the multiple beams of reception light Rx1, Rx2, Rx3,.... For example, when the first transmission light Tx1 emitted at time t0 is reflected from an external object and the first reception light Rx1 is received at time t1 by the receiver 140, the electric reception signal can be obtained by interference between the local oscillator light having a frequency component of the continuous wave light emitted from the continuous wave light source 110 at time t1 and the first reception light Rx1. In addition, when the second transmission light Tx2 is emitted at time t2 and the second reception light Rx2 is received at time t3, the electric reception signal can be obtained by interference between the local oscillator light having a frequency component of the continuous wave light emitted from the continuous wave light source 110 at time t3 and the second reception light Rx2. Similarly, when the third transmission light Tx3 is emitted at time t4 and the third reception light Rx3 is received at time t5, the electric reception signal can be obtained by interference between the local oscillator light having a frequency component of the continuous wave light emitted from the continuous wave light source 110 at time t5 and the third reception light Rx3.

[0065] The first reception light Rx1, the second reception light Rx2, and the third reception light Rx3 have a frequency component that changes according to the relative speed of the object. For example, when the relative speed with respect to the object is 0, the first reception light Rx1 can have the same frequency component as the continuous wave light emitted from the continuous wave light source 110 at time t0. In addition, when the object approaches, the first reception light Rx1 can have a higher frequency component than the frequency component of the continuous wave light emitted from the continuous wave light source 110 at time t0. Conversely, when the object moves away, the first reception light Rx1 can have a lower frequency component than the frequency component of the continuous wave light emitted from the continuous wave light source 110 at time t0.

[0066] The signal processor 150 can extract distance information and velocity information about the external object based on the electrical reception signal provided from the receiver 140. For example, the signal processor 150 can be configured to analyze the frequency of the reception signal in a frequency-modulated continuous wave (FMCW) manner to extract the distance information and the velocity information about the object. In particular, the signal processor 150 can analyze the frequency of the reception signal in a linear FMCW manner. To this end, the signal processor 150 can control the frequency modulator 120 to perform frequency modulation such that the frequency of the continuous wave light emitted from the continuous wave light source 110 linearly increases over a time period of the third time T3. For example, during the third time T3, the frequency of the continuous wave light emitted from the continuous wave light source 110 can linearly increase from a minimum frequency to a maximum frequency, and then can linearly increase again from the minimum frequency to the maximum frequency in the third time T3 thereafter.

[0067] Figure 4 is a graph showing a frequency component of the transmitted light and a frequency component of the received light in the linear FMCW method. In Figure 4 , the vertical axis of the graph represents the frequency, and the horizontal axis of the graph represents the time. Between the transmitted light and the received light, the time delay in the horizontal direction is Δt, and the frequency difference in the vertical direction is f b According to the linear FMCW method, the distance information and the velocity information can be extracted by performing a two-dimensional fast Fourier transform (FFT) on an M×N matrix obtained via M times of sampling in the frequency domain and N times of sampling in the time domain. Here, M and N are natural numbers greater than 1. For example, the distance information can be obtained by performing the FFT in the frequency domain, and the velocity information can be obtained by performing the FFT in the time domain.

[0068] In addition, the signal processor 150 can extract the distance information about the object in a ToF manner by using a time difference between the time when the transmitted light is emitted and the time when the received light is received. There are various ToF methods for acquiring the distance information. Generally, since it is difficult to directly and accurately measure the time difference, the distance information about the object can be extracted by using a phase difference between the transmitted light and the received light, which is obtained by analyzing the waveform of the reception signal. In this case, by cross-correlation between the reception signal and the transmission signal, only a signal component related to the transmission signal can be obtained from the reception signal, and the accuracy of the distance measurement can be improved by analyzing the waveform of the signal component related to the transmission signal.

[0069] Therefore, the signal processor 150 can obtain distance information using the FMCW method and can also obtain distance information using the ToF method. The signal processor 150 can adjust the distance information about the object by using both the distance information obtained by the FMCW method and the distance information obtained by the ToF method to further improve the accuracy of the distance measurement. For example, the distance obtained by the FMCW method and the distance obtained by the ToF method can be simply averaged. Alternatively, based on the error variation according to the distance in the FMCW method and the error variation according to the distance in the ToF method, a weighted average can be obtained by multiplying the distance obtained by the FMCW method by a first weight and the distance obtained by the ToF method by a second weight. Alternatively, only the distance obtained by the FMCW method or the distance obtained by the ToF method can be selected according to the distance range.

[0070] As described above, the LiDAR device 100 according to this exemplary embodiment generates continuous wave light by using the continuous wave light source 110 as a low-power continuous wave light source. In addition, the continuous wave light modulated by the frequency modulator 120 is amplified by the high-power optical amplifier 125 and emitted intermittently like a pulse. Therefore, the LiDAR device 100 according to the exemplary embodiment may not need to use an expensive high-power continuous wave light source. In addition, since the high-power optical amplifier 125 is only temporarily operated for a short period of time, the power consumption of the LiDAR device 100 according to this exemplary embodiment is low. In addition, since frequency-modulated light is used, the reflected light can be received using the receiver 140 with a narrower frequency band, thereby effectively suppressing noise.

[0071] exist Figure 3 In the exemplary embodiment shown, the beam steering device 130 can be configured to emit frequency-modulated continuous wave light only once within a third time period T3. For example, during the first third time period T3, the beam steering device 130 can emit first transmitted light Tx1, and the receiver 140 can receive first received light Rx1. During the subsequent third time period T3, the beam steering device 130 can emit second transmitted light Tx2, and the receiver 140 can receive second received light Rx2. In this case, the third time period T3 can be equal to the sum of the first time period T1 and the second time period T2.

[0072] However, the present disclosure is not necessarily limited thereto. For example, Figure 5 is a diagram showing a method according to another exemplary embodiment Figure 1 The timing diagram of the operation of the LiDAR device 100 is shown in FIG. Figure 5, the beam steering device 130 can be configured to emit frequency modulated continuous wave light twice during the third time T3 under the control of the signal processor 150. For example, the beam steering device 130 can emit the first transmission light Tx1 and the second transmission light Tx2 during the first third time T3 under the control of the signal processor 150. Then, the receiver 140 can receive the first reception light Rx1 and the second reception light Rx2 during the first third time T3. During the subsequent third time T3, the beam steering device 130 can emit the third transmission light Tx3 and the fourth transmission light Tx4, and the receiver 140 can receive the third reception light Rx3 and the fourth reception light Rx4. In this case, the third time T3 can be greater than the sum of the first time T1 and the second time T2. In this way, the beam steering device 130 can emit frequency modulated continuous wave light two or more times during the third time T3.

[0073] Furthermore, the beam steering device 130 may be configured to, under the control of the signal processor 150, emit transmission light toward one area in front of the beam steering device 130, and then emit transmission light toward another area in front of the beam steering device 130. In other words, the beam steering device 130 may sequentially scan multiple local areas in front of the beam steering device 130 by emitting transmission light one by one toward one area in front of the beam steering device 130. For example, the beam steering device 130 may emit first transmission light Tx1 to a first area in front of the beam steering device 130, and then emit second transmission light Tx2 to a second area different from the first area.

[0074] However, the present disclosure is not limited thereto, and in order to improve the signal-to-noise ratio (SNR), the beam steering device 130 may be configured to transmit the transmission light multiple times toward one area in front of the beam steering device 130, and then transmit the transmission light multiple times toward another area under the control of the signal processor 150. For example, the beam steering device 130 may sequentially transmit the first transmission light Tx1, the second transmission light Tx2, and the third transmission light Tx3 toward a first area in front of the beam steering device 130, and then sequentially transmit the fourth transmission light Tx4, the fifth transmission light Tx5, and the sixth transmission light Tx6 toward a second area different from the first area.

[0075] In this case, the signal processor 150 may accumulate the electrical reception signals of the first received light Rx1, the second received light Rx2, and the third received light Rx3 sequentially received from the receiver 140, and may extract the distance information and the speed information about the object in the first area based on the accumulated electrical reception signals. Subsequently, the signal processor 150 may accumulate the electrical reception signals of the fourth received light Rx4, the fifth received light Rx5, and the sixth received light Rx6 sequentially received from the receiver 140, and may extract the distance information and the speed information about the object in the second area based on the accumulated electrical reception signals.

[0076] Then, since the SNR of the received signal is improved, the accuracy can be improved compared to the case where the distance information and speed information are extracted using only one received light obtained from one area. The number of times the transmission light is continuously transmitted for one area can be selected differently according to the surrounding situation. For example, when the SNR is good, the signal processor 150 can determine to transmit the transmission light only once for one area. In addition, when the SNR is low, the signal processor 150 can determine to continuously transmit the transmission light up to 1000 times for one area. This method of accumulating multiple received signals for one same area and extracting distance information and speed information can also be applied to Figure 3 The exemplary embodiment shown.

[0077] In addition, the signal processor 150 can extract distance information and speed information about the front object by analyzing the frequency of the received signal in a triangular FMCW method. For example, Figure 6 is a diagram showing a method according to another exemplary embodiment Figure 1 The timing diagram of the operation of the LiDAR device 100 is shown. Figure 6 , the signal processor 150 may control the frequency modulator 120 to perform frequency modulation so that the frequency of the continuous wave light emitted from the continuous wave light source 110 increases linearly during the third time T3 and decreases linearly during the subsequent fourth time T4. In this case, the frequency of the continuous wave light emitted from the continuous wave light source 110 may increase linearly from the minimum frequency to the maximum frequency during the third time T3 and then decrease linearly from the maximum frequency to the minimum frequency during the subsequent fourth time T4. The signal processor 150 may control the frequency modulator 120 so that the third time T3, in which the frequency of the frequency modulated continuous wave light increases linearly, and the fourth time T4, in which the frequency of the frequency modulated continuous wave light decreases linearly, are periodically repeated.

[0078] exist Figure 6In the illustrated exemplary embodiment, the light beam steering device 130 can be configured to emit the frequency-modulated continuous wave light only once during the third time T3 and to emit the frequency-modulated continuous wave light only once during the fourth time T4. For example, during the third time T3, the light beam steering device 130 can emit the first transmitted light Tx1, and the receiver 140 can receive the first received light Rx1. During the fourth time T4, the light beam steering device 130 can emit the second transmitted light Tx2, and the receiver 140 can receive the second received light Rx2. During a subsequent third time T3, the light beam steering device 130 can emit the third transmitted light Tx3, and the receiver 140 can receive the third received light Rx3, and during a fourth time T4, the light beam steering device 130 can emit the fourth transmitted light Tx4, and the receiver 140 can receive the fourth received light Rx4. In this case, each of the third time T3 and the fourth time T4 can be equal to the sum of the first time T1 and the second time T2. In addition, in the first transmitted light Tx1 and the third transmitted light Tx3 and the first received light Rx1 and the third received light Rx3, the frequency is linearly increased, and in the second transmitted light Tx2 and the fourth transmitted light Tx4 and the second received light Rx2 and the fourth received light Rx4, the frequency is linearly decreased.

[0079] Figure 7 is a graph showing a frequency component of transmitted light and a frequency component of received light in a triangular FMCW method. In Figure 7 , the vertical axis of the graph represents the frequency, and the horizontal axis of the graph represents the time. As Figure 7 indicated, the graph of the transmitted light and the received light shows a triangular form in which the frequency is linearly increased with respect to the time and then linearly decreased with respect to the time. There is a time delay At between the frequency peak of the transmitted light and the frequency peak of the received light. The peak position of the transmitted light can be known from the local oscillator light to perform frequency analysis. The received light has only some information of the frequency rising portion and some information of the frequency decreasing portion. For example, the first received light Rx1 and the third received light Rx3 provide only some information of the frequency rising portion, and the second received light Rx2 and the fourth received light Rx4 provide only some information of the frequency decreasing portion. The signal processor 150 can determine an intersection obtained by extending the frequency rising slope of the first received light Rx1 and the third received light Rx3 and the frequency decreasing slope of the second received light Rx2 and the fourth received light Rx4 as the frequency peak of the received light.

[0080] When the relative speed of the front object is not 0, a frequency shift occurs in the received light received through the receiver 140 due to the Doppler effect. Accordingly, there is a frequency difference between the frequency peak of the transmitted light and the frequency peak of the received light. d For example, as Figure 7As shown, when the front object approaches, the frequency of the received light becomes higher than the frequency of the transmitted light. Conversely, when the front object moves away, the frequency of the received light becomes lower than the frequency of the transmitted light.

[0081] In this case, the distance R and the relative speed V of the front object can be obtained by Equation 1 and Equation 2, respectively.

[0082] [Equation 1]

[0083]

[0084] [Equation 2]

[0085]

[0086] In the above Equation 1 and 2, B denotes a frequency difference between a minimum frequency and a maximum frequency of the local oscillator light, T m denotes a time difference between the minimum frequency and the maximum frequency of the local oscillator light (i.e., a time span of the third time T3 or the fourth time T4), F bu denotes a frequency difference between the transmitted light and the received light in the frequency rising portion, F bd denotes a frequency difference between the transmitted light and the received light in the frequency falling portion, λ denotes a wavelength of the local oscillator light, which corresponds to the minimum frequency at an initial stage (i.e., t = 0), and c denotes a speed of light. The signal processor 150 can extract distance information and speed information about the object in a triangular FMCW manner by using the above Equation 1 and 2, based on a received signal obtained from the transmitted light emitted during the third time T3 and the received light formed by reflecting the transmitted light, and a received signal obtained from the transmitted light emitted during the fourth time T4 and the received light formed by reflecting the transmitted light.

[0087] In addition, even in Figure 6 In the exemplary embodiment shown, the signal processor 150 can obtain distance information by using the FMCW method, and can obtain distance information by using the ToF method. The signal processor 150 can improve the accuracy of the distance information about the object by using both the distance information obtained by the FMCW method and the distance information obtained by the ToF method.

[0088] In Figure 6In the exemplary embodiment shown, the beam steering device 130 may be configured to, under the control of the signal processor 150, emit transmission light toward one area in front of the beam steering device 130 during a third time T3 and a fourth time T4, and then emit transmission light toward another area in front of the beam steering device 130 during a subsequent third time T3 and a subsequent fourth time T4. For example, the beam steering device 130 may emit first transmission light Tx1 and second transmission light Tx2 toward a first area in front of the beam steering device 130, and then emit third transmission light Tx3 and fourth transmission light Tx4 toward a second area different from the first area.

[0089] However, the present disclosure is not limited thereto, and to improve the SNR, the beam steering device 130 may, under the control of the signal processor 150, transmit light multiple times, i.e., four or more times, toward an area in front of the beam steering device 130, and then transmit light multiple times, i.e., four or more times, toward another area. For example, the beam steering device 130 may sequentially transmit the first transmit light Tx1, the second transmit light Tx2, the third transmit light Tx3, and the fourth transmit light Tx4 toward the first area. In addition, the signal processor 150 may accumulate the electrical reception signals of the first receive light Rx1 and the third receive light Rx3 received from the receiver 140 in the frequency increase portion, and then accumulate the electrical reception signals of the second receive light Rx2 and the fourth receive light Rx4 received from the receiver 140 in the frequency decrease portion. The signal processor 150 may extract distance information and speed information about an object in the first area based on the received signals accumulated in the frequency increase portion and the received signals accumulated in the frequency decrease portion. The signal processor 150 may variably determine the number of times to continuously transmit light for one area based on the SNR of the received signals.

[0090] In addition, Figure 6 In the exemplary embodiment shown, the beam steering device 130 can be configured to emit frequency-modulated continuous wave light only once during each of the third time period T3 and the fourth time period T4. For example, the beam steering device 130 emits the first transmission light Tx1 during the first third time period T3 and the second transmission light Tx2 during the fourth time period T4. Furthermore, the beam steering device 130 emits the third transmission light Tx3 during the subsequent third time period T3 and the fourth transmission light Tx4 during the fourth time period T4. In this case, each of the third time period T3 and the fourth time period T4 can be equal to the sum of the first time period T1 and the second time period T2.

[0091] However, the present disclosure is not necessarily limited thereto. For example, Figure 8 is a diagram showing a method according to another exemplary embodiment Figure 1 The timing diagram of the operation of the LiDAR device 100 is shown. Figure 8, the light beam steering device 130 can be configured to emit the frequency-modulated continuous wave light twice during each of a third time T3 and a fourth time T4 under the control of the signal processor 150. For example, the light beam steering device 130 can emit a first transmission light Tx1 and a second transmission light Tx2 during the first third time T3 under the control of the signal processor 150, and can emit a third transmission light Tx3 and a fourth transmission light Tx4 during the fourth time T4. Then, the receiver 140 can receive a first reception light Rx1 and a second reception light Rx2 during the first third time T3, and can receive a third reception light Rx3 and a fourth reception light Rx4 during the fourth time T4. In addition, during a subsequent third time T3, the light beam steering device 130 can emit a fifth transmission light Tx5 and a sixth transmission light Tx6, and the receiver 140 can receive a fifth reception light Rx5 and a sixth reception light Rx6. In this case, each of the third time T3 and the fourth time T4 can be greater than the sum of the first time T1 and the second time T2. In this way, the light beam steering device can emit the frequency-modulated continuous wave light twice or more during each of the third time T3 and the fourth time T4.

[0092] Figure 9 is a block diagram illustrating a schematic configuration of a LiDAR device 200 according to another exemplary embodiment. Referring to Figure 9 , the LiDAR device 200 according to another exemplary embodiment can include a continuous wave light source 110 that generates continuous wave light, a light beam steering device 130 that emits the continuous wave light emitted from the continuous wave light source 110 to the outside, a receiver 140 that receives light reflected from an external object to form a reception signal, and a signal processor 150 configured to extract distance information and velocity information about the object based on the reception signal formed by the receiver 140. In addition, the LiDAR device 200 can further include a beam splitter 115 that divides the continuous wave light emitted from the continuous wave light source 110 and provides a majority of the continuous wave light to the light beam steering device 130 and a remainder to the receiver 140 as a local oscillator light to perform frequency analysis. In addition, the LiDAR device 200 can further include an optical amplifier 125 disposed in an optical path between the beam splitter 115 and the light beam steering device 130 to amplify the continuous wave light, and an optical amplifier controller 126 that drives the optical amplifier 125.

[0093] Figure 9 The LiDAR device 200 of Figure 1 differs from the LiDAR device 100 shown in FIG. 1 in that the LiDAR device 200 does not include the frequency modulator 120. In this case, the continuous wave light provided from the continuous wave light source 110 to the light beam steering device 130 can not be frequency-modulated but maintained at a constant frequency. Therefore,Figure 9 The operation of the LiDAR device 200 shown is the same as in the case where the frequency modulator 120 does not perform a frequency modulation operation in the LiDAR device 100 of Figure 1 The LiDAR device 200 shown can be manufactured in the same way as the LiDAR device 100 of Figure 1 In the LiDAR device 100 of Figure 1 the LiDAR device 200 can be provided at a lower cost than the LiDAR device 100 of Figure 9

[0094] Figure 10 is a timing chart schematically showing the operation of an exemplary embodiment of the LiDAR device 200 according to Figure 9 Referring to Figure 10 The beam steering device 130 can be configured to, under the control of the signal processor 150, externally emit continuous wave light only during a first time T1 and not to externally emit continuous wave light during a second time T2. In addition, the signal processor 150 can control the beam steering device 130 to periodically repeat the first time T1 for emitting continuous wave light and the second time T2 for not emitting continuous wave light. In this way, the LiDAR device 200 can sequentially emit a plurality of beams of transmission light Tx1, Tx2, Tx3,.... Each of the plurality of beams of light Tx1, Tx2, Tx3,... is similar to pulsed light in that it is continuous only for the first time T1 and interrupted for the second time T2. However, each of the plurality of beams of transmission light Tx1, Tx2, Tx3,... differs from general pulsed light in that it is continuous wave light having only one frequency component. For example, general pulsed light having a square wave or a triangular wave waveform, etc. can have a fundamental frequency component and a plurality of harmonic frequency components.

[0095] The receiver 140 receives each of the plurality of beams of reception light Rx1, Rx2, Rx3,... reflected from external objects and returned, and generates an electrical reception signal. As described above, the electrical reception signal can be obtained from interference light generated by interference between a local oscillator light for frequency analysis and each of the plurality of beams of reception light Rx1, Rx2, Rx3,.... The frequency components of the plurality of beams of reception light Rx1, Rx2, Rx3,... are changed by the Doppler effect according to the relative speed of the object. The signal processor 150 can be configured to extract distance information about the object by analyzing the waveform of the reception signal using the ToF method, and to extract speed information about the object by analyzing the frequency of the reception signal according to the Doppler method.

[0096] Also in​Figure 10 In the illustrated example, the light beam steering device 130 can be configured to emit the transmission light toward one region in front of the light beam steering device 130 and then toward another region in front of the light beam steering device 130 under the control of the signal processor 150. Alternatively, the light beam steering device 130 can be configured to emit the transmission light toward one region in front of the light beam steering device 130 multiple times and then toward another region multiple times under the control of the signal processor 150. The signal processor 150 can accumulate a plurality of electrical reception signals obtained from a plurality of beams of reception light reflected from the same region, and can extract distance information and velocity information about an object in the region based on the accumulated electrical reception signals.

[0097] The above-described LiDAR devices 100 and 200 can be installed on a vehicle and configured to extract distance and relative velocity information from a vehicle in front of the vehicle. However, the LiDAR devices 100 and 200 are not necessarily applicable only to a vehicle. For example, in addition to a vehicle, the LiDAR devices 100 and 200 according to the presented exemplary embodiments can be installed on a ship, an airplane, a drone, etc., and can be used to search for and avoid obstacles in front of the ship, the airplane, the drone, etc.

[0098] Although not limited thereto, the exemplary embodiments can be embodied as computer readable code on a computer readable recording medium. The computer readable recording medium is any data storage device that can store data which can be thereafter read by a computer system. Examples of the computer readable recording medium include read-only memory (ROM), random-access memory (RAM), CD-ROMs, magnetic tapes, floppy disks, and optical data storage devices. The computer readable recording medium can also be distributed over networked computer systems so that the computer readable code is stored and executed in a distributed fashion. In addition, the exemplary embodiments can be written as computer programs and can be implemented in general-use or special-purpose digital computers that execute the programs as computer programs using a computer readable medium. Furthermore, it is understood that one or more units of the above-described devices and apparatuses can include circuitry, a processor, a microprocessor, etc., and can execute a computer program stored in a computer readable medium.

[0099] The foregoing exemplary embodiments are merely illustrative, and should not be construed as limiting the scope of the present teachings. The present teachings can be readily applied to other types of devices. Furthermore, the description of the exemplary embodiments is intended to be illustrative, and not to limit the scope of the claims, as the claims can include other alternatives, modifications and equivalents.

Claims

1. A light detection and ranging LiDAR device, comprising: a continuous wave light source configured to generate continuous wave light; a frequency modulator configured to drive the continuous wave light source so that the continuous wave light source generates frequency modulated continuous wave light; a beam steering device configured to transmit the frequency modulated continuous wave light toward an object during a first time and to stop transmitting the frequency modulated continuous wave light toward the object during a second time; a receiver configured to receive the frequency modulated continuous wave light reflected from the object to form a received signal; as well as a signal processor configured to obtain distance information and speed information about the object based on the received signal, The frequency modulator is configured to linearly increase the frequency of the frequency modulated continuous wave light during a third time, and the third time is equal to or greater than the sum of the first time and the second time.

2. The LiDAR device according to claim 1, wherein: The beam steering device is further configured to periodically repeat emitting the frequency-modulated continuous wave light during the first time period and stopping emitting the frequency-modulated continuous wave light during the second time period.

3. The LiDAR device according to claim 1, wherein: The second time is greater than the first time.

4. The LiDAR device according to claim 1, wherein: The first time is in the range of 1 ns to 1000 ns.

5. The LiDAR device according to claim 1, further comprising: a beam splitter configured to provide a first portion of the frequency modulated continuous wave light generated by the continuous wave light source to the beam steering device, so that the first portion of the frequency modulated continuous wave light is emitted to the object and reflected from the object and then received by the receiver, and the beam splitter is configured to provide a second portion of the frequency modulated continuous wave light to the receiver, The receiver is further configured to form the received signal by combining the first portion of the frequency modulated continuous wave light received by the receiver with the second portion of the frequency modulated continuous wave light provided from the beam splitter, and causing the first portion and the second portion of the frequency modulated continuous wave light to interfere with each other.

6. The LiDAR device according to claim 1, further comprising: The optical amplifier is configured to amplify the frequency modulated continuous wave light generated by the continuous wave light source and provide the amplified frequency modulated continuous wave light to the beam steering device during the first time, and stop amplifying and outputting the frequency modulated continuous wave light during the second time.

7. The LiDAR device according to claim 1, wherein: The light beam steering device is further configured to: emit the frequency modulated continuous wave light multiple times toward a first area in front of the light beam steering device, and then emit the frequency modulated continuous wave light multiple times toward a second area different from the first area.

8. The LiDAR device according to claim 7, wherein: The signal processor is further configured to: accumulating a plurality of first reception signals received from the first area, and obtaining distance information and speed information about a first object in the first area based on the accumulated plurality of first reception signals; as well as A plurality of second reception signals received from the second area are accumulated, and distance information and speed information about a second object in the second area are obtained based on the accumulated plurality of second reception signals.

9. The LiDAR device according to claim 1, wherein: The signal processor is further configured to obtain distance information and speed information about the object by analyzing the frequency of the received signal in a frequency modulated continuous wave (FMCW) manner.

10. The LiDAR device according to claim 1, wherein: The third time is equal to the sum of the first time and the second time, and Wherein, the light beam steering device is further configured to emit the frequency modulated continuous wave light once during the third time period.

11. The LiDAR device according to claim 1, wherein: The third time is greater than the sum of the first time and the second time, and the beam steering device is further configured to emit the frequency-modulated continuous wave light multiple times during the third time.

12. The LiDAR device according to claim 1, wherein: The frequency modulator is further configured to linearly increase the frequency of the frequency modulated continuous wave light during the third time, and linearly decrease the frequency of the frequency modulated continuous wave light during the fourth time, and The third time for increasing the frequency of the frequency modulated continuous wave light and the fourth time for decreasing the frequency of the frequency modulated continuous wave light are repeated periodically.

13. The LiDAR device according to claim 12, wherein: Each of the third time and the fourth time is equal to the sum of the first time and the second time, and The light beam steering device is further configured to emit the frequency modulated continuous wave light once during the third time period, and to emit the frequency modulated continuous wave light once during the fourth time period.

14. The LiDAR device according to claim 12, wherein: Each of the third time and the fourth time is greater than the sum of the first time and the second time, and The light beam steering device is further configured to emit the frequency modulated continuous wave light multiple times during the third time period, and to emit the frequency modulated continuous wave light multiple times during the fourth time period.

15. The LiDAR device according to claim 12, wherein: The signal processor is further configured to obtain distance information and speed information about the object in an FMCW manner based on a received signal obtained from reflected light of the frequency modulated continuous wave light emitted during the third time and a received signal obtained from reflected light of the frequency modulated continuous wave light emitted during the fourth time.

16. The LiDAR device according to claim 9, wherein: The signal processor is further configured to obtain distance information about the object by analyzing a waveform of the received signal in a time-of-flight (ToF) manner.

17. The LiDAR device according to claim 16, wherein: The signal processor is further configured to adjust the distance information about the object based on the distance information extracted in the ToF manner and the distance information extracted in the FMCW manner.

18. The LiDAR device according to claim 1, wherein: The signal processor is further configured to extract distance information about the object by analyzing a waveform of the received signal in a ToF manner, and obtain speed information about the object by analyzing a frequency of the received signal in a Doppler manner.

19. A method for sensing an object using a light detection and ranging (LiDAR) device, the method comprising: Generate frequency modulated continuous wave light; dividing the frequency modulated continuous wave light into a first part and a second part; amplifying a first portion of the frequency modulated continuous wave light; intermittently transmitting a first portion of the amplified frequency modulated continuous wave light toward an object, wherein the first portion of the amplified frequency modulated continuous wave light is reflected from the object and received by a receiver of the LiDAR device; providing a second portion of the frequency modulated continuous wave light to the receiver; generating a received signal by combining the amplified first portion of the frequency modulated continuous wave light and the second portion of the frequency modulated continuous wave light received by the receiver; as well as obtaining distance information and speed information about the object based on the received signal, wherein intermittently emitting the first portion of the amplified frequency modulated continuous wave light toward the object comprises: emitting the first portion of the amplified frequency modulated continuous wave light toward the object during a first time period, and stopping emitting the first portion of the amplified frequency modulated continuous wave light toward the object during a second time period, and The frequency of the FMCW light increases linearly during a third time, and the third time is equal to or greater than the sum of the first time and the second time.

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