Depth information generation device and depth information generation method thereof

Abstract

A depth information generation device according to an embodiment of the present invention comprises: a light-emitting unit that irradiates a target region, including a plurality of transmission pulses; a light-receiving unit that receives a plurality of reception pulses that are incident thereon after being reflected from the target region; an information generation unit that generates depth information about the target region by using time differences between the plurality of transmission pulses and the plurality of reception pulses; and a control unit that controls the light-emitting unit, the light-receiving unit, and the information generation unit, wherein the light-emitting unit sequentially irradiates the target region with the plurality of transmission pulses, and the control unit controls the plurality of transmission pulses so that the time intervals therebetween are different from one another.

Description

Depth information generating device and the method for generating depth information thereof

[0001] The present invention relates to a depth information generating device and a depth information generating method thereof.

[0002] LiDAR (Light Detection and Ranging) devices use laser pulses emitted from the device and reflected back from a target object to measure the distance to the object or to visualize it. LiDAR devices are applied in various technological fields that require 3D imaging. For example, LiDAR devices can be applied in diverse fields such as meteorology, aviation, space, and automotive. Recently, the proportion of LiDAR devices in the field of autonomous driving has been rapidly increasing.

[0003] The light-emitting unit of a typical LiDAR device generates an output light signal in the form of a pulse wave with a fixed driving frequency and irradiates it onto an object, the light-receiving unit receives an input light signal reflected from the object within a predetermined reception waiting time, and the information-generating unit generates depth information of the object using the input light signal received by the light-receiving unit.

[0004] In this case, a device that maliciously generates jamming signals may exist in the vicinity of the LiDAR device, or another LiDAR device having the same driving frequency may output a pulsed light signal in the vicinity. Accordingly, the LiDAR device finds it difficult to distinguish between the input light signal reflected from its own output light signal and the interference signal from other devices, and may generate inaccurate depth information.

[0005] The technical problem that the present invention aims to solve is to provide a depth information generating device and a depth information generating method that accurately generate depth information by avoiding interference signals.

[0006] A depth information generating device according to an embodiment of the present invention comprises a light-emitting unit that irradiates a target area including a plurality of transmission pulses, a light-receiving unit that receives a plurality of reception pulses incident after being reflected from the target area, an information generating unit that generates depth information regarding the target area using the time difference between the plurality of transmission pulses and the plurality of reception pulses, and a control unit that controls the light-emitting unit, the light-receiving unit, and the information generating unit. The light-emitting unit irradiates the plurality of transmission pulses sequentially to the target area, and the control unit controls the time intervals between the plurality of transmission pulses to be different from each other.

[0007] The plurality of transmission pulses includes a first transmission pulse, a second transmission pulse, a third transmission pulse, and a fourth transmission pulse that are sequentially irradiated to the target area, and the time interval between the first transmission pulse and the second transmission pulse is the sum of a preset first time interval and a randomly set second time interval, the time interval between the second transmission pulse and the third transmission pulse is the sum of the first time interval and a randomly set third time interval, and the time interval between the third transmission pulse and the fourth transmission pulse is the sum of the first time interval and a randomly set fourth time interval, and the second time interval, the third time interval, and the fourth time interval may be different from each other.

[0008] The above second time interval, the above third time interval, and the above fourth time interval can be randomly set by a random number generator.

[0009] The information generating unit can generate depth information regarding the target area using the first time difference between the first transmission pulse and the first receiving pulse input to the light receiving unit within the first time interval after the output of the first transmission pulse, the second time difference between the second receiving pulse input to the light receiving unit within the first time interval after the output of the second transmission pulse and the second transmission pulse, and the third time difference between the third receiving pulse input to the light receiving unit within the first time interval after the output of the third transmission pulse.

[0010] The time interval between the plurality of transmission pulses can be controlled to be larger than a preset first time interval.

[0011] The depth information generating unit can generate depth information regarding the target area from a histogram of the cumulative number of times per time difference between the plurality of transmitted pulses and the plurality of received pulses input to the light receiving unit.

[0012] An optical output device according to one embodiment of the present invention includes a light-emitting unit that sequentially irradiates a plurality of transmission pulses onto a target area, and a control unit that controls the time intervals between the plurality of transmission pulses to be different from each other, wherein the time intervals between the plurality of transmission pulses are greater than a preset time interval and are set randomly.

[0013] A depth information generation method of a depth information generation device according to one embodiment of the present invention comprises the steps of sequentially irradiating a target area with a plurality of transmission pulses, receiving a plurality of reception pulses, and generating depth information regarding the target area using the time difference between the plurality of transmission pulses and the plurality of reception pulses, wherein the time interval between the plurality of transmission pulses is controlled to be different from one another.

[0014] The plurality of transmission pulses includes a first transmission pulse, a second transmission pulse, a third transmission pulse, and a fourth transmission pulse that are sequentially irradiated to the target area, and the time interval between the first transmission pulse and the second transmission pulse is the sum of a preset first time interval and a randomly set second time interval, the time interval between the second transmission pulse and the third transmission pulse is the sum of the first time interval and a randomly set third time interval, and the time interval between the third transmission pulse and the fourth transmission pulse is the sum of the first time interval and a randomly set fourth time interval, and the second time interval, the third time interval, and the fourth time interval may be different from each other.

[0015] The above second time interval, the above third time interval, and the above fourth time interval can be randomly set by a random number generator.

[0016] In the step of generating the depth information, a first time difference between the first transmission pulse and the first reception pulse input to the light receiving unit within the first time interval after the output of the first transmission pulse, a second time difference between the second transmission pulse and the second reception pulse input to the light receiving unit within the first time interval after the output of the second transmission pulse, and a third time difference between the third transmission pulse and the third reception pulse input to the light receiving unit within the first time interval after the output of the third transmission pulse may be used.

[0017] The time interval between the plurality of transmission pulses is controlled to be greater than a preset first time interval, and in the step of generating the depth information, a histogram of the cumulative number of times according to the time difference between the plurality of transmission pulses and the plurality of reception pulses input to the light receiving unit can be generated.

[0018] According to an embodiment of the present invention, a depth information generating device and a depth information generating method thereof can be obtained, which accurately generate depth information by avoiding interference signals. In particular, according to an embodiment of the present invention, since the detection distance of the depth information generating device can be changed in real time, it can be applied to short-range, medium-range, and long-range detection.

[0019] FIG. 1 is a block diagram of a lidar device according to one embodiment of the present invention.

[0020] FIG. 2 is a flowchart of an information generation method according to one embodiment of the present invention.

[0021] Figure 3 is an example of the operation of a lidar device in an ideal environment.

[0022] Figure 4 is a distance histogram according to the driving example of Figure 3.

[0023] Figure 5 is an example of the operation of a LiDAR device in a real environment.

[0024] Figure 6 is a distance histogram according to the driving example of Figure 5.

[0025] FIG. 7 is a transmission pulse of a lidar device according to one embodiment of the present invention.

[0026] FIG. 8 is an example of operation of a lidar device according to one embodiment of the present invention.

[0027] Figure 9 is a distance histogram according to the driving example of Figure 8.

[0028] FIG. 10 is an exploded view of a lidar device according to an embodiment of the present invention.

[0029] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0030] However, the technical concept of the present invention is not limited to some of the described embodiments but can be implemented in various different forms, and within the scope of the technical concept of the present invention, one or more of the components among the embodiments may be selectively combined or substituted.

[0031] In addition, terms used in the embodiments of the present invention (including technical and scientific terms) may be interpreted in a meaning that is generally understood by those skilled in the art to which the present invention belongs, unless explicitly and specifically defined otherwise. Terms that are commonly used, such as terms defined in advance, may be interpreted in consideration of their meaning in the context of the relevant technology.

[0032] Furthermore, the terms used in the embodiments of the present invention are for the purpose of describing the embodiments and are not intended to limit the present invention.

[0033] In this specification, the singular form may include the plural form unless specifically stated otherwise in the text, and when described as "at least one of A and B and C (or more than one)," it may include one or more of all combinations that can be formed from A, B, and C.

[0034] In addition, terms such as first, second, A, B, (a), (b), etc. may be used when describing the components of the embodiments of the present invention.

[0035] These terms are intended merely to distinguish a component from other components and are not limited by the nature, order, sequence, etc., of the said component.

[0036] And, where it is stated that a component is 'connected', 'combined', or 'joined' to another component, this may include not only cases where the component is directly connected, combined, or joined to the other component, but also cases where it is 'connected', 'combined', or 'joined' due to another component located between the component and the other component.

[0037] Furthermore, when described as being formed or placed "above or below" each component, "above" or "below" includes not only cases where two components are in direct contact with each other, but also cases where one or more other components are formed or placed between the two components. Additionally, when expressed as "above or below," it may include the meaning of a downward direction as well as an upward direction relative to a single component.

[0038] In an embodiment of the present invention, the depth information generating device may be a Lidar device or a Radar device. Although the present specification focuses on describing Lidar devices, the embodiments of the present invention may be applied to various depth information generating devices including Lidar devices and Radar devices. In this specification, the depth information generating device may be referred to as an information generating device, a camera device, a Lidar device, a Radar device, etc. A Lidar device according to an embodiment of the present invention may refer to a Lidar device mounted on a vehicle to measure the distance between the vehicle and an object, but is not limited thereto. A Lidar device according to an embodiment of the present invention may extract depth information using the Time of Flight (ToF) principle or the Frequency Modulation Continuous Wave (FMCW) principle.

[0039] FIG. 1 is a block diagram of a lidar device according to one embodiment of the present invention.

[0040] Referring to FIG. 1, a lidar device (1000) according to an embodiment of the present invention includes a light-emitting unit (100), a light-receiving unit (200), an information-generating unit (300), and a control unit (400).

[0041] The light-emitting unit (100) can generate and output an output light signal in the form of a pulse wave or a continuous wave. The continuous wave may be in the form of a sinusoid wave or a squared wave. By generating the output light signal in the form of a pulse wave or a continuous wave, the LiDAR device (1000) can detect a time difference or phase difference between the output light signal output from the light-emitting unit (100) and the input light signal input to the light-receiving unit (200) after being reflected from the target area. In this specification, output light refers to light that is output from the light-emitting unit (100) and incident on an object, and input light may refer to light that is output from the light-emitting unit (100), reaches the target area, is reflected from the target area, and input to the light-receiving unit (200). In this specification, the pattern of the output light may be referred to as the light-emitting pattern, and the pattern of the input light may be referred to as the incident pattern. From the perspective of the target area, the output light can be the incident light, and the input light can be the reflected light.

[0042] The light-emitting part (100) includes a light source and a lens group.

[0043] The light source generates and outputs laser pulses. The light source may utilize a light-emitting diode (LED) and may have a form in which multiple light-emitting diodes are arranged according to a specific pattern. Alternatively, the light source may include an organic light-emitting diode (OLED) or a laser diode (LD). Alternatively, the light source may be a Vertical Cavity Surface Emitting Laser (VCSEL). A VCSEL is a type of laser diode that converts an electrical signal into an optical signal and can output a wavelength of approximately 800 to 1000 nm, for example, approximately 850 nm or approximately 940 nm. The light source generates an output light signal in the form of a pulse wave or a continuous wave by repeatedly switching on and off at regular time intervals. The regular time interval may be the frequency of the output light signal.

[0044] A lens group can concentrate light output from a light source and output the concentrated light to the outside. The lens group may be positioned above the light source and spaced apart from the light source. Here, the above of the light source may refer to the side from which light is output from the light source. The lens group may include at least one lens, and if the lens group includes multiple lenses, each lens may be aligned with respect to a central axis to form an optical system. Here, the central axis may be the same as the optical axis of the optical system. The lens group may also include a diffusion member that receives light output from the light source and then refracts or diffracts the received light to output it.

[0045] The light receiving unit (200) can receive a light signal reflected from a target area. At this time, the received light signal may be a light signal output by the light emitting unit (100) that has been reflected from the target area.

[0046] The light receiving unit (200) includes an image sensor, a filter placed on the image sensor, and a group of lenses placed on the filter.

[0047] A light signal reflected from a target area can pass through a lens group of a light receiving unit (200). The optical axis of the lens group of the light receiving unit (200) can be aligned with the optical axis of an image sensor. A filter can be placed between the lens group of the light receiving unit (200) and the image sensor. The filter can be placed on the optical path between the target area and the image sensor. The filter can filter light having a predetermined wavelength range. The filter can pass light of a specific wavelength. For example, the filter can pass light in the infrared band and block light outside the infrared band. The image sensor receives a light signal and can output the received light signal as an electrical signal. The image sensor can detect light of a wavelength corresponding to the wavelength of light output by the light emitting unit (100). For example, the image sensor can detect light in the infrared band.

[0048] An image sensor can be configured with a structure in which multiple pixels are arranged in a grid shape.

[0049] The light receiving unit (200) and the light emitting unit (100) can be arranged side by side. The light receiving unit (200) can be placed next to the light emitting unit (100). The light receiving unit (200) can be placed in the same direction as the light emitting unit (100). The light emitting unit (100) and the light receiving unit (200) can be synchronized. The time at which the light emitting unit (100) outputs an output light signal and the time at which the image sensor of the light receiving unit (200) turns on can be set to be synchronized.

[0050] The information generation unit (300) generates information regarding a target area using an input light signal input to the light receiving unit (200). The information regarding the target area may include three-dimensional information regarding the target area. For example, the information regarding the target area may include depth information regarding the target area. For example, the information generation unit (300) can calculate the depth information of an object using the flight time taken from the output light signal output from the light emitting unit (100) until it is reflected from the object and input to the light receiving unit (200). For example, the information generation unit (300) can calculate the time difference between the output light signal and the input light signal using an electrical signal received by an image sensor, and calculate the distance between the target area and the LiDAR device (1000) using the calculated time difference. For example, the information generation unit (300) can calculate the phase difference between the output light signal and the input light signal using an electrical signal received from an image sensor, and calculate the distance between the target area and the LiDAR device (1000) using the calculated phase difference.

[0051] The control unit (400) controls the operation of the light-emitting unit (100), the light-receiving unit (200), and the information generation unit (300). The information generation unit (300) and the control unit (400) may be implemented in the form of a printed circuit board (PCB). Additionally, the information generation unit (300) and the control unit (400) may be implemented in the form of other configurations. Alternatively, the control unit (400) may be included in a terminal or vehicle in which the lidar device (1000) according to an embodiment of the present invention is installed. For example, the control unit (400) may be implemented in the form of an application processor (AP) of a smartphone equipped with the lidar device (1000) according to an embodiment of the present invention, or in the form of an electronic control unit (ECU) of a vehicle equipped with the lidar device (1000) according to an embodiment of the present invention.

[0052] The lidar device (1000) according to an embodiment of the present invention may be a solid-state lidar or a mechanical lidar. The solid-state lidar may be, for example, one of a MEMS (Micro Electro Mechanical System) lidar, a flash lidar, or an OPA (Optical Phase Array) lidar. In a MEMS lidar, the tilt angle of the mirror may be slightly changed by an electrical signal. In a flash lidar, an optical flash is used, and a single large-area laser pulse may illuminate the forward environment. In an OPA, an optical phase modulator controls the speed of light passing through the lens, and accordingly, the optical wavefront shape may be controlled. The mechanical lidar may be a mechanical lidar that rotates 360°.

[0053] FIG. 2 is a flowchart of an information generation method according to one embodiment of the present invention.

[0054] Referring to FIG. 2, the light-emitting unit (100) generates an output light signal and irradiates it onto a target area (S200). At this time, the light-emitting unit (100) may irradiate the output light signal onto the target area with a preset FOV. The preset FOV may include a first direction FOV and a second direction FOV. In one embodiment, the first direction FOV may be a horizontal direction FOV and the second direction FOV may be a vertical direction FOV. In another embodiment, the first direction FOV may be a vertical direction FOV and the second direction FOV may be a horizontal direction FOV.

[0055] Next, the light receiving unit (200) receives an input light signal that is input after being reflected from the target area (S210), and the information generating unit (300) generates information about the target area using the input light signal input to the light receiving unit (200) (S220). With respect to steps S200 to S220, redundant descriptions of content identical to those described with reference to FIG. 1 are omitted.

[0056] According to an embodiment of the present invention, an output light signal includes a plurality of transmission pulses that are output sequentially, and an input light signal includes a plurality of reception pulses that are received sequentially, and depth information is generated using the time difference between the plurality of transmission pulses and the plurality of reception pulses.

[0057] Figure 3 is an example of operation of a lidar device in an ideal environment, and Figure 4 is a distance histogram according to the operation example of Figure 3.

[0058] Referring to FIG. 3, the light-emitting unit (100) of the lidar device (1000) sequentially irradiates a plurality of transmission pulses (TP#1, ..., TP#N) onto a target area. At this time, the light-emitting unit (100) outputs a plurality of transmission pulses (TP#1, ..., TP#N) at a fixed driving frequency, and accordingly, the time interval between the first transmission pulse (TP#1) and the second transmission pulse (TP#2) is the same as the time interval between the second transmission pulse (TP#2) and the third transmission pulse (TP#3), and the time interval between the second transmission pulse (TP#2) and the third transmission pulse (TP#3) is the same as the time interval between the third transmission pulse (TP#3) and the fourth transmission pulse (TP#4). Meanwhile, the light-receiving unit (200) receives a plurality of reception pulses (RP#1, ..., RP#N) corresponding to the plurality of transmission pulses (TP#1, ..., TP#N). After the light-emitting unit (100) outputs a first transmission pulse (TP#1), the light-receiving unit (200) receives a first reception pulse (RP#1) within a preset reception waiting time; after the light-emitting unit (100) outputs a second transmission pulse (TP#2), the light-receiving unit (200) receives a second reception pulse (RP#2) within a preset reception waiting time; and after the light-emitting unit (100) outputs a third transmission pulse (TP#3), the light-receiving unit (200) receives a third reception pulse (RP#3) within a preset reception waiting time. The LiDAR device (1000) can generate depth information of a target area using the time difference between the first transmission pulse (TP#1) and the first reception pulse (RP#1), the time difference between the second transmission pulse (TP#2) and the second reception pulse (RP#2), and the time difference between the third transmission pulse (TP#3) and the third reception pulse (RP#3).

[0059] Here, the reception waiting time may be referred to as the unambiguous range or pulse repetition interval (PRI), and may be the time taken for a pulse to travel back and forth within the maximum recognition range of the lidar device (1000). The reception waiting time may vary depending on the specifications of the lidar device (1000). For example, the preset reception waiting time of a long-range lidar device may be longer than the preset reception waiting time of a medium-range lidar device.

[0060] Referring to FIG. 4, the horizontal axis of the distance histogram represents the time difference between the transmitted pulse and the received pulse, and the vertical axis of the distance histogram represents the cumulative count. A higher cumulative count on the distance histogram indicates a higher probability of distribution of the received pulse, and depth information of the target area can be generated based on the time difference with a high probability of distribution of the received pulse.

[0061] Figure 5 is an example of operation of a LiDAR device in a real environment, and Figure 6 is a distance histogram according to the operation example of Figure 5.

[0062] Referring to FIG. 5, the light-emitting unit (100) of the lidar device (1000) sequentially irradiates a plurality of transmission pulses (TP#1, ..., TP#N) to a target area. At this time, the light-emitting unit (100) outputs a plurality of transmission pulses (TP#1, ..., TP#N) at a fixed driving frequency, and accordingly, the time interval between the first transmission pulse (TP#1) and the second transmission pulse (TP#2) is the same as the time interval between the second transmission pulse (TP#2) and the third transmission pulse (TP#3), and the time interval between the second transmission pulse (TP#2) and the third transmission pulse (TP#3) is the same as the time interval between the third transmission pulse (TP#3) and the fourth transmission pulse (TP#4).

[0063] However, in an actual environment, the receiving unit (200) may not be able to receive some of the receiving pulses (e.g., RP#2, RP#3, RP#4, RP#6) for multiple transmitting pulses (TP#1, ..., TP#N) within the receiving waiting time due to various influences such as signal strength, interference signals, and surrounding environment. For example, if the signal strength is strong enough to receive pulse signals from a distance greater than the specified specifications of the lidar device (1000), the receiving pulse for the first transmitting pulse (TP#1) may be received during the receiving waiting time between the second transmitting pulse (TP#2) and the third transmitting pulse (TP#3), rather than during the receiving waiting time between the first transmitting pulse (TP#1) and the second transmitting pulse (TP#2). Alternatively, if the lidar device (1000) is in an environment with many reflectors, such as a tunnel or a bridge, the transmitting pulse may be reflected multiple times and received via multipath. In addition, the receiving unit (200) may receive pulse signals or maliciously induced jamming signals from other lidar devices located around the lidar device (1000), and if the driving frequency of the other device is the same as the driving frequency of the lidar device (1000), the lidar device (1000) may have difficulty distinguishing between its own transmission pulse and the interference pulse of the other device.

[0064] Accordingly, referring to FIG. 6, which is a distance histogram in an actual environment, not only is it impossible to receive a receiving pulse corresponding to some of the transmitting pulses of the lidar device (1000), but interference pulses due to noise are also mixed along with the receiving pulses corresponding to the transmitting pulses of the lidar device (1000), so there may be multiple points where the distribution probability of the receiving pulses is above a certain level, and inaccurate depth information may be generated.

[0065] In an embodiment of the present invention, the control unit (400) controls the time intervals between a plurality of transmission pulses to be different from each other. Accordingly, the lidar device (1000) can avoid interference caused by pulse signals from other lidar devices located nearby or maliciously induced jamming signals, and can generate depth information more accurately.

[0066] FIG. 7 is a transmission pulse of a lidar device according to one embodiment of the present invention, FIG. 8 is an example of operation of a lidar device according to one embodiment of the present invention, and FIG. 9 is a distance histogram according to the example of operation of FIG. 8.

[0067] Referring to FIG. 7, the light-emitting unit (100) of the lidar device (1000) sequentially irradiates a plurality of transmission pulses (TP#1, ..., TP#N) onto a target area. At this time, the time intervals between the plurality of transmission pulses (TP#1, ..., TP#N) are different from each other. That is, the plurality of transmission pulses (TP#1, ..., TP#N) output by the light-emitting unit (100) of the lidar device (1000) may not have a fixed driving frequency. For example, according to an embodiment of the present invention, the time interval between the first transmission pulse (TP#1) and the second transmission pulse (TP#2) is the sum of a preset first time interval (T1) and a second time interval (T2), the time interval between the second transmission pulse (TP#2) and the third transmission pulse (TP#3) is the sum of a preset first time interval (T1) and a third time interval (T3), and the time interval between the third transmission pulse (TP#3) and the fourth transmission pulse (TP#4) may be the sum of a preset first time interval (T1) and a fourth time interval (T4). Here, the preset first time interval (T1) may be an unambiguous range or a pulse repetition interval (PRI), and may be the time taken for a pulse to travel back and forth within the maximum recognition range of the lidar device (1000). The preset first time interval (T1) may vary depending on the specifications of the lidar device (1000). For example, the preset first time interval (T1) of the long-range lidar device may be longer than the preset first time interval (T1) of the medium-range lidar device.

[0068] According to an embodiment of the present invention, the time interval between a plurality of transmission pulses (TP#1, ..., TP#N) may be greater than the first time interval (T1), which is an unambiguous range or pulse repetition interval (PRI). Accordingly, within the distance recognition range of the lidar device (1000), the time interval from when the light-emitting unit (100) outputs a transmission pulse until the light-receiving unit (200) receives a reception pulse can be guaranteed.

[0069] According to an embodiment of the present invention, the second time interval (T2), the third time interval (T3), and the fourth time interval (T4) may be different from each other. For example, the second time interval (T2), the third time interval (T3), and the fourth time interval (T4) may be set randomly. Accordingly, the light-emitting unit (100) of the lidar device (1000) may output a transmission pulse and output the next transmission pulse after a first time interval (T1) and a random waiting time have elapsed.

[0070] At this time, the second time interval (T2), the third time interval (T3), and the fourth time interval (T4) can be randomly set by a random number generator. To this end, the control unit (400) may further include a random number generator or be connected to an external random number generator.

[0071] According to an embodiment of the present invention, the first time interval (T1) may be larger than each of the second time interval (T2), the third time interval (T3), and the fourth time interval (T4). For example, the first time interval (T1) may be 0.01 times or more and less than 1 time of each of the second time interval (T2), the third time interval (T3), and the fourth time interval (T4), preferably 0.1 times or more and 0.9 times or less. Accordingly, while the second time interval (T2), the third time interval (T3), and the fourth time interval (T4) are set randomly, the time interval between transmission pulses is not set to be more than twice the first time interval (T1), so the resolution of the depth information can be guaranteed.

[0072] Referring to FIG. 8, the light receiving unit (200) receives a plurality of receiving pulses (RP#1, ..., RP#N) corresponding to a plurality of transmitting pulses (TP#1, ..., TP#N). After the light emitting unit (100) outputs a first transmitting pulse (TP#1), the light receiving unit (200) receives a first receiving pulse (RP#1) corresponding to the first transmitting pulse (TP#1) within a preset first time interval, and after the light emitting unit (100) outputs a second transmitting pulse (TP#2), the light receiving unit (200) receives a second receiving pulse (RP#2) corresponding to the second transmitting pulse (TP#2) within a preset first time interval, and after the light emitting unit (100) outputs a third transmitting pulse (TP#3), the light receiving unit (200) receives a third receiving pulse (RP#3) corresponding to the third transmitting pulse (TP#3) within a preset first time interval. The lidar device (1000) can generate depth information of a target area using the time difference between a first transmission pulse (TP#1) and a first reception pulse (RP#1), the time difference between a second transmission pulse (TP#2) and a second reception pulse (RP#2), and the time difference between a third transmission pulse (TP#3) and a third reception pulse (RP#3).

[0073] As illustrated in FIG. 8, the light receiving unit (200) may receive not only a plurality of receiving pulses (RP#1, ..., RP#N) corresponding to a plurality of transmitting pulses (TP#1, ..., TP#N), but also pulse signals from other lidar devices located around the lidar device (1000) or maliciously induced jamming signals. However, when a plurality of transmitting pulses (TP#1, ..., TP#N) are output at random intervals as in the embodiment of the present invention, the reception time of a plurality of receiving pulses (RP#1, ..., RP#N) corresponding to a plurality of transmitting pulses (TP#1, ..., TP#N) has regularity based on the output time of the plurality of transmitting pulses (TP#1, ..., TP#N), whereas pulse signals from other lidar devices located around the lidar device (1000) or maliciously induced jamming signals become irregular. This can be understood through the distance histogram of FIG. 9. Referring to FIG. 9, the horizontal axis of the distance histogram represents the time difference between the transmitted pulse and the received pulse, and the vertical axis of the distance histogram represents the cumulative count. A higher cumulative count on the distance histogram may indicate a higher probability of distribution of the received pulse. A received signal that has regularity based on the output times of multiple transmitted pulses (TP#1, ..., TP#N) is accumulated and amplified, but pulse signals from other LiDAR devices located around the LiDAR device (1000) that are received irregularly based on the output times of multiple transmitted pulses (TP#1, ..., TP#N) or maliciously induced jamming signals are not accumulated and are scattered within the histogram. Even if a received pulse (e.g., RP#4, RP#5) corresponding to some of the transmitted pulses among the multiple transmitted pulses (TP#1, ..., TP#N) is not received, the cumulative count of the received pulse may be significantly greater than the cumulative count of the interference pulse.Accordingly, the lidar device (1000) can avoid interference by distinguishing between a receiving pulse corresponding to a transmitting pulse it outputs and a pulse signal from another lidar device located around the lidar device (1000) or a maliciously induced jamming signal, and can accurately generate depth information.

[0074] According to an embodiment of the present invention, the first time interval (T1) is fixed, and the second time interval (T2), the third time interval (T3), and the fourth time interval (T4) can be varied. As described above, the second time interval (T2), the third time interval (T3), and the fourth time interval (T4) are controlled by a control unit (400) and can be randomly set by a random number generator.

[0075] Alternatively, the first time interval (T1) may be varied, and the second time interval (T2), third time interval (T3), and fourth time interval (T4) may also be varied. As described above, the second time interval (T2), third time interval (T3), and fourth time interval (T4) are controlled by the control unit (400) and may be randomly set by a random number generator. The first time interval (T1) may be varied according to user settings. For example, when the user sets the lidar device according to the embodiment of the present invention for long distance and when it is set for medium distance, the control unit (400) may set the first time interval (T1) differently. Alternatively, the first time interval (T1) may be varied by the control unit (400). For example, if the LiDAR device according to an embodiment of the present invention determines, as a result of generating depth information in advance, that a target object is closer than an initial set value, the control unit (400) can reduce the first time interval (T1), and if the target object is determined to be farther than an initial set value, the control unit (400) can increase the first time interval (T1). Accordingly, since the LiDAR device according to an embodiment of the present invention can adaptively adjust the time interval between transmission pulses according to the distance to the target object, not only can the resolution of the depth information be increased, but time efficiency can also be improved.

[0076] According to an embodiment of the present invention, the light-emitting unit (100) and the light-receiving unit (200) of the lidar device (1000) can be synchronized. That is, when the control unit (400) of the lidar device (1000) controls the time intervals between a plurality of transmission pulses (TP#1, ..., TP#N) to be different from each other, the control unit (400) can also control the light-receiving unit (200) to be synchronized with the time intervals between the plurality of transmission pulses (TP#1, ..., TP#N). For example, when the control unit (400) of the lidar device (1000) controls the time intervals between a plurality of transmission pulses (TP#1, ..., TP#N) to be different from each other, the control unit (400) can control the on / off timing of the image sensor of the light-receiving unit (200) to correspond to the time intervals between the plurality of transmission pulses (TP#1, ..., TP#N). According to this, the probability of receiving pulse signals from other lidar devices located around the lidar device (1000) or maliciously induced jamming signals is minimized, thereby increasing the accuracy of depth information generation.

[0077] FIG. 10 is an exploded view of a lidar device according to an embodiment of the present invention.

[0078] A LiDAR device may include a light-emitting unit and a light-receiving unit. However, components such as a substrate (10), a holder (30), and a shield can (50) are formed integrally and used in common for both the light-emitting unit and the light-receiving unit, so it may be difficult to distinguish between the light-emitting unit and the light-receiving unit. In this case, each of the above components may be understood as a component of the light-emitting unit and the light-receiving unit, respectively. However, as a variation, common components such as the substrate (10), the holder (30), and the shield can (50) may be provided separately for the light-emitting unit and the light-receiving unit, respectively.

[0079] The light-emitting part may include a substrate (10), a light source (20), a holder (30), a diffusion member (41), a diffuser ring (42), and a shield can (50). The light-receiving part may include a substrate (10), a sensor (60), a filter (80), a holder (30), a lens (70), a barrel (71), and a shield can (50).

[0080] The substrate (10) may include a printed circuit board (PCB). The substrate (10) may be connected to a connector via an FPCB (91). The substrate (10) and the FPCB (91) may be formed from a rigid flexible PCB (RFPCB). A light source (20) and a sensor (60) may be placed on the substrate (10). The substrate (10) may be placed under a holder (30). The substrate (10) may include terminals. The terminals of the substrate (10) may be connected to the coupling portion of the shield can (50). The terminals of the substrate (10) may include a plurality of terminals. The terminals of the substrate (10) may include two terminals.

[0081] A light source (20) may be placed on a substrate (10). A light source (20) may be placed in contact with the substrate (10). A light source (20) may be placed on the substrate (10). A light source (20) may be placed on the substrate (10). The light source (20) may correspond to the light source (110) described above.

[0082] The holder (30) may be placed on the substrate (10). The holder (30) may be placed in contact with the substrate (10). The holder (30) may be placed on the substrate (10). The holder (30) may be placed on the substrate (10). The holder (30) may be fixed to the substrate (10) by an adhesive. The holder (30) may accommodate a light source (20), a diffuser module (40), a sensor (60), and a filter (80) inside. The holder (30) may be a plastic injection molded part. The holder (30) may be formed by injection molding.

[0083] The diffuser module (40) may include a diffusion member (41) and a diffuser ring (42). The diffuser module (40) may be formed integrally as in the modified example, but in this embodiment, it may be manufactured separately into a diffusion member (41) and a diffuser ring (42) to increase moldability during injection molding. The diffusion member (41) and the diffuser ring (42) may be separated from each other.

[0084] The diffusion member (41) may be a diffuser lens. The diffusion member (41) may correspond to the previously described diffusion member (120) and diffusion member (400). The diffusion member (41) may be placed within the holder (30). The diffusion member (41) may be coupled to the holder (30). The diffusion member (41) may be fixed to the holder (30). The diffusion member (41) may be placed on the optical path of light emitted from the light source (20). The diffusion member (41) may be placed on the light source (20). The diffusion member (41) may be placed above the light source (20). The diffusion member (41) may be a plastic injection molded product. The diffusion member (41) may be formed by plastic injection molding. The height of the top of the diffusion member (41) may correspond to the height of the top of the lens (70). The diffusion member (41) can be inserted in the upward direction of the vertical direction and combined with the holder (30). At this time, the upward direction may be a direction from the bottom of the holder (30) toward the top of the holder (30). A portion of the diffusion member (41) may overlap with the holder (30) in the upward direction.

[0085] The diffuser ring (42) can be placed within the holder (30). The diffuser ring (42) can be fixed to the holder (30). The diffuser ring (42) can be coupled to the holder (30). The diffuser ring (42) can be placed below the diffusion member (41). The diffuser ring (42) can support the diffusion member (41). The diffuser ring (42) can be in contact with the diffusion member (41). The diffuser ring (42) can be a plastic injection molded product. The diffuser ring (42) can be formed by plastic injection molding.

[0086] The shield can (50) can cover the body portion of the holder (30). The shield can (50) may include a cover. The shield can (50) may include a cover can. The shield can (50) may be a non-magnetic material. The shield can (50) may be formed from a metal material. The shield can (50) may be formed from a metal plate. The shield can (50) may be electrically connected to the substrate (10). The shield can (50) may be connected to the substrate (10) through a solder ball. Through this, the shield can (50) may be grounded. The shield can (50) may block electromagnetic interference (EMI). At this time, the shield can (500) may be referred to as an 'EMI shield can'. In this embodiment, as a high voltage is used inside the optical device, electronic interference noise may increase, and the shield can (50) can block the electronic interference noise.

[0087] The sensor (60) can be placed on the substrate (10). The sensor (60) can be placed on the other side of the partition wall of the holder (30) on the substrate (10). That is, the sensor (60) can be placed on the opposite side of the light source (20) with respect to the partition wall of the holder (30). The sensor (60) can detect infrared light. The sensor (60) can detect light of a specific wavelength among infrared light. The sensor (60) can detect light that has passed through the filter (80). The sensor (60) can detect light in the wavelength band of the light source (20). Through this, the sensor (60) can detect light emitted from the light source (20) and reflected from the subject, thereby sensing 3D image information of the subject. The effective sensing area of ​​the sensor (60) is placed to correspond to the diffusion member (41), but the sensor (60) can be placed so as to be offset towards the partition wall overall. A circuit pattern of the sensor (60) can be placed in the part of the sensor (60) that is offset toward the bulkhead.

[0088] The lens (70) can be fixed within the barrel (71). The lens (70) may be a plastic injection molded product. The lens (70) may be formed by plastic injection molding. The lens (70) may include a plurality of lenses.

[0089] The filter (80) can be placed between the lens (70) and the sensor (60). The filter (80) may be a band-pass filter that allows light of a specific wavelength range to pass through. The filter (80) may allow infrared light to pass through. The filter (80) may allow light of a specific wavelength among infrared light to pass through. The filter (80) may allow light of a wavelength band of light emitted by the light source (20) to pass through. The filter (80) may block visible light. The filter (80) may be coupled to the holder (30). A groove of a size corresponding to the filter (80) is formed in the holder (30), and the filter (80) may be inserted into the groove and fixed with adhesive. An adhesive injection groove may be formed in the groove of the holder (30) to inject adhesive between the filter (80) and the holder (30). The filter (80) may be placed at a position lower than the position of the diffuser ring (42).

[0090] Although the invention has been described above with reference to embodiments, this is merely illustrative and does not limit the invention. Those skilled in the art will understand that various modifications and applications not exemplified above are possible within the scope of the essential characteristics of the embodiments. For example, each component specifically shown in the embodiments may be modified and implemented. Furthermore, differences related to such modifications and applications should be interpreted as being included within the scope of the invention as defined in the appended claims.

Claims

1. A light-emitting unit that irradiates a target area including a plurality of transmission pulses, A light receiving unit that receives a plurality of receiving pulses incident after being reflected from the above target area, An information generating unit that generates depth information regarding the target area using the time difference between the plurality of transmission pulses and the plurality of reception pulses, and It includes a control unit that controls the light-emitting unit, the light-receiving unit, and the information-generating unit, and The light-emitting unit sequentially irradiates the plurality of transmission pulses onto the target area, and The above control unit is a depth information generating device that controls the time intervals between the plurality of transmission pulses to be different from each other.

2. In Paragraph 1, The plurality of transmission pulses above include a first transmission pulse, a second transmission pulse, a third transmission pulse, and a fourth transmission pulse that are sequentially irradiated onto the target area, and The time interval between the first transmission pulse and the second transmission pulse is the sum of a preset first time interval and a randomly set second time interval, the time interval between the second transmission pulse and the third transmission pulse is the sum of the first time interval and a randomly set third time interval, and the time interval between the third transmission pulse and the fourth transmission pulse is the sum of the first time interval and a randomly set fourth time interval. The above second time interval, the above third time interval, and the above fourth time interval are depth information generating devices that are different from each other.

3. In Paragraph 2, The above second time interval, the above third time interval, and the above fourth time interval are depth information generating devices randomly set by a random number generator.

4. In Paragraph 2, The above information generating unit is a depth information generating device that generates depth information regarding the target area using the first time difference between the first transmission pulse and the first receiving pulse input to the light receiving unit within the first time interval after the output of the first transmission pulse, the second time difference between the second receiving pulse input to the light receiving unit within the first time interval after the output of the second transmission pulse and the second transmission pulse, and the third time difference between the third receiving pulse input to the light receiving unit within the first time interval after the output of the third transmission pulse.

5. In Paragraph 1, A depth information generating device in which the time interval between the plurality of transmission pulses is controlled to be greater than a preset first time interval.

6. In Paragraph 5, The depth information generating unit is a depth information generating device that generates depth information regarding the target area from a histogram of the cumulative number of times per time difference between the plurality of transmission pulses and the plurality of reception pulses input to the light receiving unit.

7. A light-emitting unit that sequentially irradiates a target area with multiple transmission pulses, and It includes a control unit that controls the time intervals between the plurality of transmission pulses to be different from each other, and An optical output device in which the time interval between the plurality of transmission pulses is greater than the preset time interval and is set randomly.

8. In a method for generating depth information of a depth information generating device, Step of sequentially irradiating a target area with multiple transmission pulses, A step of receiving multiple received pulses, and The method includes the step of generating depth information regarding the target area using the time difference between the plurality of transmission pulses and the plurality of reception pulses. A depth information generation method in which the time intervals between the plurality of transmission pulses are controlled to be different from each other.

9. In Paragraph 8, The plurality of transmission pulses above include a first transmission pulse, a second transmission pulse, a third transmission pulse, and a fourth transmission pulse that are sequentially irradiated onto the target area, and The time interval between the first transmission pulse and the second transmission pulse is the sum of a preset first time interval and a randomly set second time interval, the time interval between the second transmission pulse and the third transmission pulse is the sum of the first time interval and a randomly set third time interval, and the time interval between the third transmission pulse and the fourth transmission pulse is the sum of the first time interval and a randomly set fourth time interval. The above second time interval, the above third time interval, and the above fourth time interval are different depth information generation methods.

10. In Paragraph 9, The above second time interval, the above third time interval, and the above fourth time interval are a depth information generation method randomly set by a random number generator.

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