Apparatus and method for inspecting angular resolution of lidar device

Abstract

The present invention provides a method for inspecting the angular resolution of a LiDAR device, comprising the steps of: preparing a LiDAR device to be inspected and at least one target; rotating, in N steps, the LiDAR device to be inspected, in the azimuth direction or altitude direction, and recording, at each rotation angle of the N steps, a plurality of frames for the target through the LiDAR device to be inspected; selecting, from the frames, at least one data point among data points calculated by the LiDAR device to be inspected; and determining, on the basis of the selected data point, the angular resolution of the LiDAR device to be inspected.

Description

Device and method for inspecting each resolution of a lidar device

[0001] The present invention relates to a lidar device. More specifically, the present invention relates to performance testing of a lidar device, for example, testing the angular resolution of a lidar device.

[0002] Lidar devices are crucial sensors for detecting the shape and distance of objects, and are utilized in diverse industries, including autonomous vehicles, drones, and robots. Lidar devices use light to scan their surroundings and, based on the collected data, generate a point cloud, a collection of data points in 3D space. The quality of this point cloud is significantly influenced by the performance of the Lidar device. Angular resolution is a key performance indicator of this Lidar device.

[0003] Angular resolution refers to the minimum angular difference a lidar device can detect within a specific angle. A lidar device with high angular resolution can detect objects in greater detail. Therefore, a lidar device's angular resolution can be a key indicator for evaluating its performance.

[0004] The angular resolution of a LiDAR device can be measured based on data points derived from light reflected from the edge of the target object being scanned. Typically, the measurer visually determines whether a data point is located at the edge of the target object. However, because the extent to which a data point exists near the edge of the target object can vary, the criteria for determining under what circumstances a data point is located at the edge of the target object remain unclear.

[0005] Additionally, the process of measuring the angular resolution of a lidar device typically involves rotating the lidar device using a rotating device. If the angular resolution of the rotating device itself is not sufficiently low, there is a possibility that data points will not be generated at the edges of the target object.

[0006] In addition, if distortion occurs in the point cloud itself produced by the lidar device, there is also a problem that the measured resolution may differ depending on which of the multiple data points is used as a reference for measuring each resolution.

[0007] Therefore, there is a need for a method to measure each resolution using more objective and consistent criteria rather than relying on the subjective judgment of the measurer.

[0008] An object of the present invention is to provide a device and method for inspecting each resolution of a lidar device that does not depend on the subjective judgment of a measurer.

[0009] In addition, an object of the present invention is to provide an angular resolution inspection device and method of a lidar device that is not affected by the angular resolution of the rotating device itself that rotates the lidar device.

[0010] In addition, an object of the present invention is to provide a device and method for inspecting each resolution of a lidar device that is not affected by the distortion of the point cloud itself produced by the lidar device.

[0011] In order to solve the problem of the present invention, a method for inspecting each resolution of a lidar device is provided, comprising: a step of preparing an inspection target lidar device and at least one target; a step of rotating the inspection target lidar device in an azimuth direction or an altitude direction in n steps, and recording a plurality of frames for the target through the inspection target lidar device at each rotation angle of the n steps; a step of selecting at least one data point among data points produced by the inspection target lidar device from the frames; and a step of determining each resolution of the inspection target lidar device based on the selected data point.

[0012] According to one embodiment of the present invention, the step of determining each resolution of the inspection target lidar device based on the selected data point may include the step of determining each resolution of the inspection target lidar device based on a fitted depth graph and a partial average depth for the selected data point.

[0013] According to one embodiment of the present invention, the method further includes a step of arranging the inspection target lidar device and the target, wherein the target includes a main target and a sub-target, the main target is arranged such that an edge directly faces the optical center of the inspection target lidar device, and the sub-target can be arranged parallel to the main target and behind the main target in a direction away from the inspection target lidar device.

[0014] According to one embodiment of the present invention, the inspection target lidar device can rotate by a preset angle in each of the n steps.

[0015] According to one embodiment of the present invention, the selected data points may be sequentially adjacent in a horizontal or vertical direction.

[0016] According to one embodiment of the present invention, the step of determining each resolution of the inspection target lidar device based on the suitable depth graph and partial average depth for the selected data point may include the step of obtaining depth information of the data point.

[0017] According to one embodiment of the present invention, the step of determining each resolution of the inspection target lidar device based on the suitable depth graph and partial average depth for the selected data point may further include the step of calculating an average depth for the data point from the depth information.

[0018] According to one embodiment of the present invention, the step of determining each resolution of the inspection target lidar device based on the fitted depth graph and the partial average depth for the selected data point may further include the step of generating the fitted depth graph by plotting the average depth against the rotation angle.

[0019] According to one embodiment of the present invention, the step of determining each resolution of the inspection target lidar device based on the fitted depth graph and the partial average depth for the selected data point may further include the steps of: calculating the partial average depth for at least some of the average depths; identifying a pair of data points among the selected data points having the same value of the partial average depth; calculating, for each of the pair of data points, the rotation angle corresponding to the partial average depth having the same value on the fitted depth graph for each of the pair of data points; identifying the number of data points that exist sequentially adjacent in a horizontal direction or a vertical direction between the pair of data points; and determining the angular resolution of the inspection target lidar device based on the corresponding rotation angle for the pair of data points and the number of the data points.

[0020] In order to solve the problem of the present invention, an angular resolution inspection device of a LiDAR device is provided, comprising: an inspection target device support unit for supporting an inspection target device; a rotation adjustment unit for rotating the inspection target device support unit and the inspection target device; and a processor unit for controlling operations of the inspection target device and the rotation adjustment unit and determining an angular resolution of the inspection target device based on information output by the inspection target device and the rotation adjustment unit.

[0021] According to one embodiment of the present invention, the processor unit may be configured to perform the steps of: rotating the inspection target lidar device in n steps in the azimuth direction or the altitude direction, and recording a plurality of frames for the target through the inspection target lidar device at each rotation angle of the n steps; selecting at least one data point among data points produced by the inspection target lidar device from the frames; and determining an angular resolution of the inspection target lidar device based on the selected data point.

[0022] According to one embodiment of the present invention, the step of determining each resolution of the inspection target lidar device based on the selected data point may include the step of determining each resolution of the inspection target lidar device based on a fitted depth graph and a partial average depth for the selected data point.

[0023] According to one embodiment of the present invention, the target includes a main target and a sub-target, the main target is arranged so that the optical center and edge of the inspection target lidar device are directly facing each other, and the sub-target can be arranged parallel to the main target and behind the main target in a direction away from the inspection target lidar device.

[0024] According to one embodiment of the present invention, the inspection target lidar device can rotate by a preset angle in each of the n steps.

[0025] According to one embodiment of the present invention, the selected data points may be sequentially adjacent in a horizontal or vertical direction.

[0026] According to one embodiment of the present invention, the step of determining each resolution of the inspection target lidar device based on the suitable depth graph and partial average depth for the selected data point may include the step of obtaining depth information of the data point.

[0027] According to one embodiment of the present invention, the step of determining each resolution of the inspection target lidar device based on the suitable depth graph and partial average depth for the selected data point may further include the step of calculating an average depth for the data point from the depth information.

[0028] According to one embodiment of the present invention, the step of determining each resolution of the inspection target lidar device based on the fitted depth graph and the partial average depth for the selected data point may further include the step of generating the fitted depth graph by plotting the average depth against the rotation angle.

[0029] According to one embodiment of the present invention, the step of determining each resolution of the inspection target lidar device based on the fitted depth graph and the partial average depth for the selected data point may further include the steps of: calculating the partial average depth for at least some of the average depths; identifying a pair of data points among the selected data points having the same value of the partial average depth; calculating, for each of the pair of data points, the rotation angle corresponding to the partial average depth having the same value on the fitted depth graph for each of the pair of data points; identifying the number of data points that exist sequentially adjacent in a horizontal direction or a vertical direction between the pair of data points; and determining the angular resolution of the inspection target lidar device based on the corresponding rotation angle for the pair of data points and the number of the data points.

[0030] In order to solve the problem of the present invention, a method for inspecting each resolution of a LiDAR device is provided, comprising: a step of arranging at least one target spaced apart from a LiDAR device to be inspected; a step of observing a point cloud through the LiDAR device to be inspected; a step of rotating the LiDAR device to be inspected to shift at least one point and at least one point in a row or column from an edge of the target; a step of acquiring depth information at each rotation angle until at least one of the one point and the points in the row or column deviates from the target; a step of rotating the LiDAR device to be inspected until the same depth information is acquired within the precision of the LiDAR device to be inspected; and a step of acquiring each resolution by considering the number of data points between the same depth information within the precision of the LiDAR device to be inspected.

[0031] In order to solve the problem of the present invention, a method for inspecting each resolution of a LiDAR device is provided, comprising: a step of placing a LiDAR device to be inspected on a rotation stage at a distance from at least one target; a step of irradiating light from the LiDAR device to be inspected to an edge area of ​​the target so that a point cloud can be observed; a step of rotating the rotation stage according to a rotation angle preset in an azimuth direction or an altitude direction, and recording a plurality of frames for the target through the LiDAR device to be inspected at each rotation angle; a step of obtaining a suitable depth graph at each rotation angle from the frames; a step of obtaining, from the suitable depth graph, the depth information included within a tolerance range according to the precision of the LiDAR device to be inspected and the rotation angle having the depth information included within the tolerance range; and a step of determining the angular resolution of the LiDAR device to be inspected based on the rotation angle having the depth information.

[0032] The device and method for inspecting each resolution of a lidar device according to the present invention can determine each resolution of the lidar device based on depth information for a plurality of data points produced over a plurality of frames by rotating the lidar device in a plurality of steps.

[0033] Figure 1 is a schematic diagram for explaining the operation of a light detection and distance measurement device or lidar device to which the present invention is applied.

[0034] FIG. 2 is a drawing showing each resolution inspection device of a lidar device according to one embodiment of the present invention.

[0035] FIG. 3 is a schematic diagram illustrating the arrangement between each resolution inspection device of a lidar device and at least one target according to one embodiment of the present invention.

[0036] FIG. 4 is a conceptual diagram for explaining the relationship between the arrival point on the target of light emitted from the inspection target device according to the present invention and the data point calculated based on the light reflected from the target.

[0037] FIG. 5 illustrates a plurality of data points generated by the inspection target device from light reaching the edge of the target and light reflected from the target at a rotation angle at which light emitted from the inspection target device according to the present invention reaches the edge of the target.

[0038] FIG. 6 is a drawing showing the average depth calculated based on multiple data points produced by the inspection target device in FIG. 5 displayed on a coordinate plane.

[0039] Figure 7 is a conceptual diagram for explaining the process of generating a suitable depth graph and calculating a partial average depth according to the present invention.

[0040] Figure 8 illustrates multiple fitted depth graphs for the data points illustrated in Figure 7.

[0041] FIG. 9 is a flowchart illustrating a method for inspecting each resolution of a lidar device according to one embodiment of the present invention.

[0042] Below, with reference to the attached drawings, a detailed description will be given of each resolution inspection method and system for a lidar device according to an embodiment of the present invention. However, the attached drawings are provided solely to facilitate the disclosure of the present invention, and it will be readily apparent to those skilled in the art that the scope of the present invention is not limited to the scope of the attached drawings.

[0043] Introduction

[0044] Figure 1 is a schematic diagram for explaining the operation of a light detection and distance measurement device or lidar device to which the present invention is applied.

[0045] Referring to FIG. 1, a light detection and distance measurement device (100, hereinafter also referred to as a LIDAR device) to which the present invention is applied may include a light emitter (110) for emitting light, a light detector (120) for detecting reflected light reflected from an object (200) and returning the emitted light, and an optical device (130) provided in a light path emitted and received from the light emitter (110) and the light detector (120). Here, the light emitter (110) may be a diode or laser light source. The LIDAR device may calculate a range or property of an object (200) by using reflected light reflected from an object (200).

[0046] In this specification, the device under test may be interchangeably referred to as a lidar device.

[0047] A point cloud refers to a collection of data points in 3D space. The collection of data points generated by the LIDAR device to which the present invention is applied can also be considered a point cloud. Since the distances between the data points constituting a point cloud are generally non-uniform, it is desirable to specifically encode all three coordinates (Cartesian or spherical) for each point.

[0048] According to the present invention, the device to be tested is called a device under test (DUT).

[0049] Among the results where the measurement value is positive, a true measurement value (TP) is an accurate measurement value, that is, both the measurement value and the result are positive. Among the results where the measurement value is positive, a false positive (FP) is an incorrect measurement value, that is, the measurement value is positive but the result is negative.

[0050] The probability of a valid point in a single measurement and / or accumulated multiple measurements for a single target is called the probability of detection (PoD) or true positive rate. The detection probability may depend on background noise, target reflectivity, range tolerance, and other properties. PoD can be calculated by the following mathematical expression 1, where true (TP) represents the scan points that are overall hits on the target detected at a distance (actual) ±Δ. The detection probability is calculated as the ratio of the number of valid points to the number of theoretical points.

[0051] [Mathematical Formula 1]

[0052]

[0053] In the point cloud of a LiDAR device, the angle formed by the connection between two adjacent detection points and the three-dimensional coordinate origin of the point cloud in azimuth and elevation angles is called angular resolution. The angular resolution of a LiDAR device can be divided into azimuth resolution and elevation resolution.

[0054] In a point cloud of a LiDAR device, the angle between the two outermost valid points where the PoD exceeds 50% (50% Lambertian target reflectivity) is called the field of view (FOV). The FOV range includes the horizontal FOV range and the vertical FOV range.

[0055] Capturing the entire FOV (horizontal / vertical) is called a frame.

[0056] Overall configuration of each resolution inspection device of the lidar device

[0057] FIG. 2 is a drawing showing each resolution inspection device of a lidar device according to one embodiment of the present invention.

[0058] As shown in Fig. 2, the inspection device (10) may include a support unit for the inspection target device (11), a rotation adjustment unit (12), a processor unit (13), and a memory unit (14).

[0059] The inspection target device support member (11) is for supporting the inspection target device. More specifically, the inspection target device support member (11) can be combined with the inspection target device to support the inspection target device, and can rotate together with the inspection target device by a rotation adjustment member (12) as described below.

[0060] The rotation adjustment unit (12) is for rotating the inspection target device and the inspection target device support unit (11). The rotation adjustment unit (12) can be connected to the inspection target device support unit (11) and can rotate the inspection target device support unit (11) and / or the inspection target device.

[0061] The processor unit (13) can control the operation of the rotation adjustment unit (12). In addition, the processor unit (13) can control the operation of the inspection target device connected to the inspection device (10). As described below, the processor unit (13) can process the information output by the inspection target device connected to the inspection device (10) and the rotation adjustment unit (12), and can determine the angular resolution of the inspection target device by processing the above information.

[0062] The memory unit (14) can store information output by the inspection target device connected to the inspection device (10). The memory unit (14) can store information generated by the processor unit (14) based on the information output by the inspection target device. The memory unit (14) can record a program for controlling the operation of the rotation adjustment unit (12) and processing the information output by the inspection target device to enable the processor unit (13) to perform an operation of determining each resolution of the inspection target device.

[0063] An inspection device (10) according to one embodiment of the present invention can rotate an inspection target device and produce a plurality of data points across a plurality of frames, and can acquire and / or produce depth data, an average depth, a fitted depth graph, and a partial average depth for the plurality of data points. The depth data, the average depth, the fitted depth graph, and the partial average depth will be described later with reference to FIGS. 4 and 5.

[0064] FIG. 3 is a schematic diagram illustrating the arrangement between each resolution inspection device of a lidar device and at least one target according to one embodiment of the present invention. FIG. 3 (a), (b), and (c) are a perspective view, a front view, and a plan view illustrating the arrangement between the inspection device and the target.

[0065] According to the present invention, each resolution inspection device (10) of a lidar device is for determining each resolution of a device to be inspected. At this time, the device to be inspected may be a lidar device.

[0066] As illustrated in FIG. 3, the inspection device (10) may be arranged with at least one target. The at least one target may include a main target (20) and a sub-target (21). The main target (20) and the sub-target (21) may be arranged at a predetermined distance from the inspection device (10).

[0067] When the inspection device (10) performs scanning in a horizontal direction, the main target (20) and the sub-target (21) can be placed side by side in the horizontal direction while being spaced apart from each other by a predetermined distance from the inspection device (10).

[0068] When the inspection device (10) performs scanning in the vertical direction, the main target (20) and the sub-target (21) can be placed side by side in the vertical direction while being spaced apart from each other by a predetermined distance from the inspection device (10).

[0069] Although not shown in FIG. 3, as described below, the inspection device (10) may be connected to a device to be inspected. For example, the inspection device (10) may be connected to a lidar device.

[0070] As illustrated in (a) of FIG. 3, the distance (d1) between the inspection device (10) and the main target (20) may be smaller than the distance (d2) between the inspection device (10) and the sub-target (21). Here, the distance between the inspection device (10) and the target may mean a straight-line distance between the inspection target device and the target connected to the inspection device (10). For example, the distance between the inspection device (10) and the target may mean the length of the component perpendicular to the target among the components perpendicular to the target and the horizontal components of the target, in a line segment connecting the optical origin of the lidar device connected to the inspection device (10) and an arbitrary point located on the target.

[0071] As shown in (b) and (c) of FIG. 3, the main target (20) may be arranged so that the optical center and edge of the inspection target device connected to the inspection device (10) face each other head-on. In addition, the sub-target (21) may be arranged parallel to the main target (20) at the rear of the main target (20) in a direction away from the inspection device (10). The main target (20) and the sub-target (21) may be arranged so that at least a portion of the sub-target (21) is obscured from the view when viewed head-on from the inspection device (10). The main target (20) and the sub-target (21) may be arranged so that, when viewed head-on from the inspection device (10), the edge of the main target (20) appears to overlap on the sub-target (21) arranged at the rear. Alternatively, the main target (20) and the sub-target (21) may be arranged so that the respective edges of the main target (20) and the sub-target (21) overlap when viewed from the front on the inspection device (10). In the former case, when viewed from the front on the inspection device (10), the edge of the main target (20) may form a boundary surface (a-a'). In the latter case, when viewed from the front on the inspection device (10), the edges of the main target (20) and the sub-target (21) may form a boundary surface (a-a'). In the following description, the former case is described as an example, but the spirit of the present invention may also be applied to the latter case.

[0072] The main target (20) and the sub-target (21) may be positioned so that a portion of the edge of the main target (20) overlaps the sub-target (21) positioned at the rear. The main target (20) and the sub-target (21) may be positioned so as to clearly define the reference for the depth information measured according to the position of each data point produced. Accordingly, the main target (20) and the sub-target (21) may be positioned so that a portion of the main target (20) and the sub-target (21) overlap.

[0073] According to the present invention, the target may include only the main target (20) and may not include the sub-target (21). In this case, a background located behind the main target (20) may take the place of the sub-target (21).

[0074] Hereinafter, with reference to FIGS. 4 to 8, each resolution inspection device (10) of a lidar device according to one embodiment of the present invention will be described in detail.

[0075] Inspection environment

[0076] The inspection device (10) and method may have a condition that the target reflectivity falls within a specific numerical range. The target reflectivity is preferably 10% or more and 90% or less, but is not limited thereto.

[0077] The inspection device (10) and method may have a condition that the target dimensions fall within a specific numerical range. The target dimensions may be sufficient to measure each resolution depending on the specifications of the device to be inspected.

[0078] The inspection device (10) and method may be conditioned on the temperature of the space where the inspection is performed being within a specific numerical range. The temperature of the space where the inspection is performed is preferably room temperature. For example, the temperature of the space where the inspection is performed is preferably 22.5 degrees Celsius or higher and 23.5 degrees Celsius or lower, but is not limited thereto.

[0079] Movement of arrival points and data points according to rotation

[0080] FIG. 4 is a conceptual diagram for explaining the relationship between the arrival point on the target of light emitted from the inspection target device according to the present invention and the data points calculated based on the light reflected from the target. FIG. 4 (a) illustrates the arrival point on the target of light emitted from the inspection target device. FIG. 4 (b) illustrates a plurality of data points calculated based on the emitted light by overlapping them. FIG. 4 (a) and (b) illustrate the light arrival points and data points at different rotation angles, respectively. That is, in FIG. 4 (a) and (b), the light arrival points and n data points at the first rotation angle are overlaid and illustrated at the top, and the light arrival points and n data points at the second rotation angle are overlaid and illustrated at the bottom.

[0081] In Fig. 4, only a total of 25 lights having a square arrangement of 5 horizontal and 5 vertical lights among the lights emitted by the inspection target device are illustrated as an example. In the following description, only the total of 25 lights illustrated in Fig. 4 are illustrated as examples, but the concept of the present invention is not interpreted as being limited by the number or arrangement of the emitted lights.

[0082] As illustrated in FIG. 4, for each of the 25 total lights emitted from the inspection target device according to the present invention, n data points are calculated from the n total lights reflected from the target over n frames. In FIG. 4 (b), n data points calculated from the n lights reflected from the target are superimposed and illustrated.

[0083] The processor unit (13) can control the operation of the rotation adjustment unit (12) to rotate the inspection target device connected to the inspection device (10) in the azimuth direction or the altitude direction. For example, when the inspection target device is a lidar device, the processor unit (13) can rotate the lidar device in the azimuth direction or the altitude direction.

[0084] According to the present invention, the processor unit (13) can control the rotation control unit (12) so that the rotation control unit (12) repeatedly rotates the device to be inspected. The angle at which the device to be inspected is repeatedly rotated may be a preset angle.

[0085] According to the present invention, as the processor unit (13) rotates the lidar device in the azimuth or elevation direction, the arrival point (31) on the target of the light emitted from the lidar device can move in the horizontal or vertical direction. The arrival point (31) may refer to the point on the target where the light emitted from the inspection target device actually reaches.

[0086] For example, as illustrated in (a) of FIG. 4, when the processor unit (13) rotates the lidar device in the azimuth direction, the arrival point (31) can move in the horizontal direction. The arrival point (31) can move so as to horizontally penetrate the boundary surface (a-a') formed by the edge of the main target (20). There may be a plurality of arrival points (31). For example, as illustrated in (a) of FIG. 4, the arrival points (31) may include a first arrival point (31a), a second arrival point (31b), a third arrival point (31c), and a fourth arrival point (31d).

[0087] According to the present invention, at least some of the reaching points (31) can move to penetrate the boundary surface (a-a') formed by the edge of the main target (20) in the horizontal or vertical direction as the inspection target device rotates. Based on the light reflected from the main target (20) or the sub-target (21) upon reaching the reaching points (31), the depth information (50) of the data points (30) produced by the inspection target device may differ between a plurality of data points (30) and between a plurality of frames.

[0088] For example, as illustrated in (a) of FIG. 4, the first arrival point (31a), the second arrival point (31b), the third arrival point (31c), and the fourth arrival point (31d) can move to horizontally penetrate the boundary surface (a-a') formed by the edge of the main target (20) as the inspection target device rotates in the azimuth direction. At this time, the depth information (50) of the data points (30) calculated by the lidar device connected to the inspection device (10) based on the light reflected from the main target (20) or the sub-target (21) by the light reaching the first arrival point (31a), the second arrival point (31b), the third arrival point (31c), and the fourth arrival point (31d) may be different from each other.

[0089] According to the present invention, a lidar device connected to an inspection device (10) can detect light that reaches an arrival point (31) on a target and is reflected again, and calculate a data point (30) based thereon. According to the present invention, n data points (30) can be calculated over a total of n frames for a set rotation angle. Fig. 4 (b) illustrates these n data points (30) by overlapping them. Each arrival point (31) may correspond to each data point (30). For example, referring to Fig. 4, a first arrival point (31a), a second arrival point (31b), a third arrival point (31c), and a fourth arrival point (31d) illustrated in Fig. 4 (a) may correspond to a first data point (30a), a second data point (30b), a third data point (30c), and a fourth data point (30d), respectively.

[0090] According to the present invention, when the inspection target device rotates step by step while changing the azimuth or elevation angle in the azimuth or elevation direction, the processor unit (13) can control the lidar device so that the lidar device connected to the inspection device (10) produces data points (30) over a plurality of frames, i.e., n, at each step. The number n of frames recorded by the lidar device at each step may be a size sufficient to measure each resolution according to the specifications of the lidar device. For example, the number n of multiple frames may be 10, but is not limited thereto.

[0091] For example, as shown in (b) of FIG. 4, the processor unit (13) can control the lidar device connected to the inspection device (10) to record n ​​frames at each rotation step.

[0092] As illustrated in (b) of Fig. 4, multiple data points (30) generated across multiple frames may be expressed overlapping each other. The positions of each of the multiple data points (30) generated by the lidar device across multiple frames may differ between the multiple data points (30) and between the multiple frames.

[0093] Depth information and average depth

[0094] FIG. 5 illustrates a plurality of data points calculated by the inspection target device from light reaching the edge of the target and light reflected from the target at a rotation angle at which light emitted from the inspection target device according to the present invention reaches the edge of the target. FIG. 5 (a) illustrates a case where the proportion of data points located on the primary target among the calculated plurality of data points is high, and FIG. 5 (b) illustrates a case where the proportion of data points located on the secondary target among the calculated plurality of data points is high.

[0095] As shown in Fig. 5, the point of arrival (31) of the light reaching the edge of the target at a rotation angle at which the light radiated from the inspection target reaches the edge of the target can be located at the boundary surface (a-a') formed by the edge of the main target (20).

[0096] As illustrated in FIG. 5, at a given rotation angle, the lidar device can record a plurality of frames. In some of the plurality of frames, the lidar device can calculate a data point (30) located in an area corresponding to the primary target (20) based on light reflected by reaching an arrival point (31) located at the boundary surface (a-a'). In addition, in some of the remaining frames, the lidar device can calculate a data point (30) located in an area corresponding to the secondary target (21) based on light reflected by reaching an arrival point (31) located at the boundary surface (a-a').

[0097] For example, as illustrated in (a) of FIG. 5, the proportion of frames in which the lidar device produces data points (30) located in an area corresponding to the main target (20) may be higher.

[0098] Additionally, for example, as illustrated in (b) of FIG. 5, the ratio of frames in which the lidar device produces data points (30) located in an area corresponding to the sub-target (21) may be higher.

[0099] According to the present invention, the processor unit (13) can control the lidar device connected to the inspection device (10) to produce data points (30) over a plurality of frames. Each data point (30) can have depth information (50).

[0100] For example, when a lidar device produces a data point (30) located in an area corresponding to a primary target (20) illustrated in FIG. 5, the data point (30) may have depth information (50) having a predetermined value. The predetermined value may be close to the distance between the lidar device connected to the inspection device (10) and the primary target (20).

[0101] Also, for example, when a lidar device produces a data point (30) located in an area corresponding to a sub-target (21) illustrated in FIG. 5, the lidar device may have depth information (50) having a predetermined value for the corresponding data point (30). The predetermined value may be close to the distance between the lidar device connected to the inspection device (10) and the sub-target (21).

[0102] According to the present invention, the processor unit (13) can receive depth information (50) from a lidar device connected to the inspection device (10). The processor unit (13) can calculate an average depth (60) based on the depth information (50). The average depth (60) means an average value of depth information (50) of data points (30) calculated by the lidar device over a plurality of frames based on light reflected at a predetermined arrival point (31) at a specific rotation angle.

[0103] Fig. 6 is a diagram showing the average depth calculated based on a plurality of data points produced by the inspection target device in Fig. 5, displayed on a coordinate plane. Fig. 6a shows the average depth when the proportion of data points located in the primary target among the produced plurality of data points is high, and Fig. 6b shows the average depth when the proportion of data points located in the secondary target among the produced plurality of data points is high.

[0104] As shown in Fig. 6, the average depth (60) calculated by the inspection target device with respect to a predetermined arrival point (31) on the target at a specific rotation angle may be different from each other as shown in (a) and (b) of Fig. 6 even though the rotation angle is the same.

[0105] For example, referring to point (P1) illustrated in FIG. 6, if the ratio of frames in which the lidar device produces data points (30) located in an area corresponding to the main target (20) is higher (see (a) of FIG. 5), the average depth (60) for that rotation angle may be A. A may be a value closer to d1 than to d2.

[0106] Also, for example, referring to point (P2) illustrated in FIG. 5, if the ratio of frames in which the lidar device produces data points (30) located in an area corresponding to the sub-target (21) is higher (see (b) of FIG. 5), the average depth (60) for that rotation angle may be B. B may be a value closer to d2 than to d1.

[0107] Fitted depth graph and partial average depth

[0108] FIG. 7 is a conceptual diagram illustrating a process of generating a suitable depth graph and calculating a partial average depth according to the present invention. FIG. 7 (a), (b), and (c) illustrate a plurality of data points calculated over a plurality of frames based on light emitted by a device to be inspected, overlaid with respect to rotation angles. FIG. 7 (d) is an example of a graph plotting the average depth calculated for the plurality of data points shown in FIG. 7 (a), (b), and (c) against the rotation angle. FIG. 7 (e) is an example of a suitable depth graph generated by fitting the graph shown in FIG. 7 (d).

[0109] As illustrated in (a), (b), and (c) of FIG. 7, the processor unit (13) can output an average depth (60) for data points (30) calculated by the lidar device over a plurality of frames for each rotation angle. The processor unit (13) can output an average depth (60) for data points (30) whose locations change from the area of ​​the primary target (20) to the area of ​​the secondary target (21) as the lidar device rotates. For example, the processor unit (13) can calculate an average depth (60) for the first data point (30a) for each rotation angle.

[0110] According to the present invention, the average depth (60) for the data point (30) can be plotted on a plane coordinate with the rotation angle (degree of rotation) and the n-frame average depth as axes, respectively. The n-frame average depth can mean the average depth (60) calculated from n data points obtained by the processor unit (13) recording n frames for each rotation angle. For example, the average depth (60) for the first data point (30a) can be plotted on a coordinate as in the graph illustrated in (d) of FIG. 7.

[0111] According to the present invention, the processor unit (13) can perform curving fitting on a graph of average depths (60) for data points (30) to generate a suitable depth graph (80). For example, as illustrated in (e) of FIG. 7, the processor unit (13) can perform curving fitting on a graph of average depths (60) for a first data point (30a) (see (d) of FIG. 7) to generate a suitable depth graph (80) (C1). An algorithm for performing curve fitting can be determined in consideration of expected characteristics of a lidar device connected to an inspection device (10).

[0112] According to the present invention, the processor unit (13) can select at least a portion of the average depth (60) for the data point (30) and calculate an average for the portion. The average is called a partial average depth (70). For example, the processor unit (13) can select an average depth (60) from a rotation step in which the data point (30) begins to enter the sub-target (21) from the main target (20) to the rotation step in which it completely moves to the sub-target (21), and calculate a partial average depth (70) for this.

[0113] The rotation phase in which the data point (30) begins to enter the sub-target (21) from the main target (20) may mean a rotation phase in which the data point (30) is calculated to be located in the sub-target (21) in at least some of the multiple frames recorded by the lidar device. In addition, the rotation phase in which the data point (30) completely moves to the sub-target (21) may mean a rotation phase in which the data point (30) is calculated to be located in the sub-target (21) in all of the multiple frames recorded by the lidar device.

[0114] For example, as illustrated in (d) of FIG. 7, the processor unit (13) can calculate a partial average depth (70) for the first data point (30a) based on the average depth (60) corresponding to points existing between the reference line (L1) and the reference line (L2). The average depth (60) corresponding to a point located on the reference line (L1) may mean the average depth (60) in the rotation step in which the first data point (30a) starts to enter the sub-target (21) from the main target (20). In addition, the average depth (60) corresponding to a point located on the reference line (L2) may mean the average depth (60) in the rotation step in which the first data point (30b) completely moves to the sub-target (21).

[0115] According to the present invention, the partial average depth (70) can be illustrated together with the fit depth graph (80). Specifically, the partial average depth (70) can be expressed as a point on the fit depth graph (80) where the function value of the n-frame average depth axis is equal to the partial average depth (70). The processor unit (13) can identify the value of the rotation angle axis corresponding to the point.

[0116] For example, as illustrated in (e) of FIG. 7, the partial average depth (70) for the first data point (30a) may be illustrated together with a fit depth graph (80) for the first data point (30a). The partial average depth (70) for the first data point (30a) may be expressed as a point (M1) on the fit depth graph (80) (C1) for the first data point (30a) where the function value of the n-frame average depth axis is equal to the partial average depth (70). The processor unit (13) may identify a value of the rotation angle axis corresponding to the point (M1).

[0117] According to the present invention, the processor unit (13) can select a plurality of data points (30) on which the above-described operation is to be performed. The plurality of data points (30) may be data points (30) that are sequentially adjacent in the horizontal direction or the vertical direction. For example, referring to (a), (b), and (c) of FIG. 7, the processor unit (13) can select a first data point (30a), a second data point (30b), a third data point (30c), and a fourth data point (30d) that are sequentially adjacent in the horizontal direction in order to determine each resolution in the azimuth direction (azimuth resolution). In addition, the processor unit (13) can perform the above-described operation on each of the first data point (30a), the second data point (30b), the third data point (30c), and the fourth data point (30d).

[0118] When determining the azimuth resolution of the device to be inspected, the processor unit (13) can perform the above-described operation and select a plurality of data points (30) that are sequentially adjacent in the horizontal direction. In addition, when determining the elevation resolution of the device to be inspected, the processor unit (13) can perform the above-described operation and select a plurality of data points (30) that are sequentially adjacent in the vertical direction.

[0119] According to the present invention, the processor unit (13) can determine each resolution of the inspection target device based on the suitable depth graph (80) and the partial average depth (70).

[0120] In this case, the influence of uncertainty that may occur in the process of identifying depth information (50) for data points (30) located near the edge of the target on the accurate determination of each resolution can be eliminated.

[0121] In addition, even if the data point (30) is not output near the edge of the target due to the angular resolution of the rotation adjustment unit (12) itself, it becomes possible to determine the angular resolution of the device to be inspected.

[0122] In addition, in this case, since multiple data points (30) are selected for each resolution determination of the device to be inspected, the problem of each resolution value determined based on a single data point (30) being different for each selected data point (30) due to distortion of the point cloud itself does not occur.

[0123] How to determine each resolution

[0124] Figure 8 illustrates multiple fitted depth graphs for the data points illustrated in Figure 7.

[0125] As described above, according to the present invention, the processor unit (13) can perform the above-described operation on a plurality of data points (30) that are sequentially adjacent in the horizontal or vertical direction.

[0126] The processor unit (13) can calculate and / or identify an average depth (60), a graph of the average depth (60), a fit depth graph (80), a partial average depth (70), and a rotation angle corresponding to the partial average depth (70) on the fit depth graph (80) for a plurality of data points (30) sequentially adjacent in the horizontal or vertical direction.

[0127] The processor unit (13) can identify a pair of data points (30) having the same partial average depth (70) value among a plurality of data points (30) sequentially adjacent in the horizontal or vertical direction.

[0128] According to the present invention, the fact that the values ​​of the partial average depth (70) are the same may include not only cases where the values ​​of the partial average depth (70) are numerically the same, but also cases where they are similar within a tolerance set for the device to be inspected. The tolerance may be the precision of the device to be inspected. Alternatively, the tolerance may be determined based on the precision of the device to be inspected.

[0129] According to the present invention, if the minimum value of the angle that the rotation adjustment unit (12) can adjust with a single operation is greater than a specific threshold value, there cannot be more than one pair of data points (30) having the same value of the partial average depth (70). The present invention is intended to overcome the technical limitations related to the minimum adjustable angle of the rotation adjustment unit (12) and to determine the angular resolution of the device to be inspected.

[0130] The processor unit (13) can identify a rotation angle corresponding to the partial average depth (70) on each suitable depth graph (80) for a pair of data points (30) having the same value of the partial average depth (70).

[0131] The processor unit (13) can identify the number of data points (30) that exist sequentially in the horizontal or vertical direction between the pair of data points (30).

[0132] The processor unit (13) can determine each resolution of the inspection target device based on the rotation angle corresponding to each partial average depth (70) of the pair of data points (30) and the number of data points (30) sequentially existing in the horizontal or vertical direction between the pair of data points (30).

[0133] The processor unit (13) can determine each resolution through the following [Mathematical Formula 2].

[0134] [Equation 2]

[0135]

[0136] X1, X2: Rotation angles corresponding to the partial average depth (70) of a pair of data points with the same average depth (60) (where X1 < X2)

[0137] N: The number of data points between the above pair of data points (including both ends)

[0138] For example, referring to FIG. 8, the processor unit (13) can calculate / identify the average depth (60), the graph of the average depth (60), the fitted depth graph (80) (C1, C2, C3, C4), the partial average depth (70) (see M1, M2, M3, M4) and the rotation angle corresponding to the partial average depth (70) on the fitted depth graph (80) (C1, C2, C3, C4) for the first data point (30a), the second data point (30b), the third data point (30c) and the fourth data point (30d) illustrated in FIG. 7, respectively.

[0139] As illustrated in FIG. 8, the processor unit (13) can identify the first data point (30a) and the fourth data point (30d) having the same partial average depth (70) value among the first data point (30a), the second data point (30b), the third data point (30c), and the fourth data point (30d) that are sequentially adjacent in the horizontal direction.

[0140] As illustrated in FIG. 8, the processor unit (13) can identify a rotation angle (X1, X2) corresponding to the partial average depth (70) on each of the suitable depth graphs (80) (C1, C4) for the first data point (30a) and the fourth data point (30d) having the same value of the partial average depth (70).

[0141] As illustrated in FIG. 8, the processor unit (13) can identify the second data point (30b) and the third data point (30c) that are sequentially present in the horizontal direction between the first data point (30a) and the fourth data point (30d) on the frame. That is, the processor unit (13) can identify that there are four data points (30) sequentially present in the horizontal direction from the first data point (30a) to the fourth data point (30d).

[0142] As illustrated in Fig. 8, the processor unit (13) can determine each resolution of the inspection target device through the above-described [Mathematical Formula 2]. More specifically, each resolution can be determined in the form of (X2 - X1) / (4 - 1).

[0143]

[0144] Method for inspecting each resolution of a lidar device

[0145] FIG. 9 is a flowchart illustrating a method for inspecting each resolution of a lidar device according to one embodiment of the present invention.

[0146] As illustrated in Fig. 9, each resolution inspection method of a lidar device may include the following steps.

[0147] The inspection method may include a step (S100) of preparing a device to be inspected and at least one target. For example, the device to be inspected may be a lidar device.

[0148] The inspection method may include a step (S200) of placing a device to be inspected and at least one target. Details regarding the placement between the device to be inspected and the target are as described above.

[0149] The inspection method may include a step (S300) of rotating the inspection target device and a step (S400) of recording multiple frames for the target through the inspection target device. More specifically, steps (S300) and (S400) may be repeatedly performed n times from i=1 to i=n, ​​where n is a natural number. That is, multiple frames may be recorded for each sequentially performed rotation step.

[0150] The inspection method may include a step (S500) of selecting a data point (30), a step (S600) of obtaining depth information (50) of the data point (30) from a plurality of frames, and a step (S700) of calculating an average depth (60) of the data point (30) from the depth information (50) of the data point (30). Steps (S600) and (S700) may be repeatedly performed n times from h=1 to h=n. For each rotation step sequentially performed by a preset angle, the average depth (60) for the data point (30) may be calculated n times. Details of the depth information (50) and the average depth (60) are as described above.

[0151] The inspection method may include a step (S800) of generating a suitable depth graph (80) for a data point (30), a step (S900) of calculating a partial average depth (70) for at least some of the average depths (60) for the data point (30), and a step (S1000) of calculating a rotation angle corresponding to the partial average depth (70) for the data point (30) on the suitable depth graph (80). Details of the suitable depth graph (80) and the partial average depth (70) are as described above.

[0152] Steps (S500), (S600), and (S700) are repeatedly performed n times, and steps (S800), (S900), and (1000) can be repeatedly performed m times from j=1 to j=m. m is a natural number greater than 1. That is, steps (S500), (S600), (S700), (S800), (S900), and (1000) can be sequentially and repeatedly performed for m data points (30).

[0153] According to the present invention, the m data points (30) may be data points (30) that penetrate the boundary surface (a-a') formed by the edge of the main target (20) while the inspection target device rotates in the horizontal or vertical direction, and may be data points (30) that are adjacent to each other in the horizontal or vertical direction. For example, when determining the azimuth resolution of the inspection target device, m data points (30) that are sequentially adjacent in the horizontal direction may be selected. Also, for example, when determining the elevation resolution of the inspection target device, m data points (30) that are sequentially adjacent in the vertical direction may be selected.

[0154] The inspection method may include a step (S1100) of identifying a pair of data points (30) having the same value of partial average depth (70) and a step (S1200) of determining each resolution of the inspection target device based on the pair of data points (30). Details of the method for determining each resolution are as described above.

[0155] According to the present invention, a method for inspecting each resolution of a lidar device may include the steps of: arranging at least one target spaced apart from a lidar device to be inspected; observing a point cloud through the lidar device to be inspected; rotating the lidar device to be inspected to shift at least one point and at least one of points in a row or column from an edge of the target; acquiring depth information at each rotation angle until at least one of the point and the points in the row or column deviates from the target; rotating the lidar device to be inspected until the same depth information is acquired within the precision of the lidar device to be inspected; and acquiring each resolution by considering the number of data points between the same depth information within the precision of the lidar device to be inspected.

[0156] According to the present invention, a method for inspecting each resolution of a lidar device may include the steps of: placing a lidar device to be inspected on a rotation stage at a distance from at least one target; irradiating light from the lidar device to be inspected to an edge area of ​​the target so that a point cloud is observed; rotating the rotation stage according to a rotation angle preset in an azimuth direction or an altitude direction, and recording a plurality of frames for the target through the lidar device to be inspected at each rotation angle; obtaining a suitable depth graph at each rotation angle from the frames; obtaining, from the suitable depth graph, the depth information included within a tolerance range according to the precision of the lidar device to be inspected and the rotation angle having the depth information included within the tolerance range; and determining the angular resolution of the lidar device to be inspected based on the rotation angle having the depth information.

[0157]

[0158] While the present invention has been described above with reference to the embodiments illustrated in the drawings, these are merely exemplary, and those skilled in the art will appreciate that various modifications and variations of the embodiments are possible. However, such modifications should be considered within the technical protection scope of the present invention. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

[0159]

[0160] [Explanation of symbols]

[0161] 10: Each resolution inspection device of the lidar device

[0162] 11: Support for the device to be inspected

[0163] 12: Rotation adjustment unit

[0164] 13: Processor section

[0165] 14: Memory section

[0166] 20: Main target

[0167] 21: Sub-target

[0168] 30: Data points

[0169] 30a: First data point

[0170] 30b: Second data point

[0171] 30c: Third data point

[0172] 30d: 4th data point

[0173] 31: Reaching point

[0174] 31a: First arrival point

[0175] 31b: Second arrival point

[0176] 31c: Third Arrival Point

[0177] 31d: 4th arrival point

[0178] 50: Depth information

[0179] 60: Average depth

[0180] 70: Partial average depth

[0181] 80: Fit depth graph

[0182] 100: Light detection and distance measurement device

[0183] 110: Light emitter

[0184] 120: Photodetector

[0185] 130: Optical devices

[0186] 200: Object

[0187] S100: Step of preparing the inspection target device and at least one target

[0188] S200: Step of placing the inspection target device and at least one target.

[0189] S300: Step of rotating the device to be inspected

[0190] S400: Step of recording multiple frames for the target through the inspection target device.

[0191] S500: Step for selecting data points (30)

[0192] S600: Step of acquiring depth information (50) of data points (30) from multiple frames

[0193] S700: A step for calculating the average depth (60) of data points (30) from the depth information (50) of data points (30).

[0194] S800: Step of generating a suitable depth graph (80) for data points (30)

[0195] S900: A step of calculating a partial average depth (70) for at least some of the average depths (60) for data points (30).

[0196] S1000: A step for calculating a rotation angle corresponding to a partial average depth (70) for a data point (30) on a suitable depth graph (80).

[0197] S1100: Step of identifying a pair of data points (30) having the same value of partial average depth (70)

[0198] S1200: A step of determining each resolution of the inspection target device based on a pair of data points (30).

Claims

1. In the method for inspecting each resolution of the lidar device, A step of preparing a lidar device to be inspected and at least one target; A step of rotating the above-described inspection target lidar device in the azimuth or elevation direction in n steps, and recording a plurality of frames for the target through the inspection target lidar device at each rotation angle of the n steps; A step of selecting at least one data point from among the data points produced by the inspection target lidar device from the frame; and A step of determining each resolution of the inspection target lidar device based on the selected data points; including, Method for inspecting the angular resolution of a lidar device.

2. In paragraph 1, The step of determining each resolution of the inspection target lidar device based on the selected data points is: A step of determining each resolution of the inspection target lidar device based on the fitted depth graph and partial average depth for the selected data points; including, Method for inspecting the angular resolution of a lidar device.

3. In paragraph 1, A step of placing the above inspection target lidar device and the target; Including more, The above targets include primary and secondary targets, The above primary target is positioned so that the edge is directly facing the optical center of the inspection target lidar device, The sub-target is arranged parallel to the main target and behind the main target in a direction away from the inspection target lidar device. Method for inspecting the angular resolution of a lidar device.

4. In paragraph 1, The above-mentioned inspection target lidar device rotates by a preset angle in each of the n steps. Method for inspecting the angular resolution of a lidar device.

5. In paragraph 1, The above selected data points are sequentially adjacent in the horizontal or vertical direction, Method for inspecting the angular resolution of a lidar device.

6. In paragraph 2, The step of determining each resolution of the inspection target lidar device based on the fitted depth graph and partial average depth for the selected data points is as follows: A step of obtaining depth information of the above data point; including, Method for inspecting the angular resolution of a lidar device.

7. In paragraph 6, The step of determining each resolution of the inspection target lidar device based on the fitted depth graph and partial average depth for the selected data points is as follows: A step of calculating an average depth for the data points from the depth information; including more, Method for inspecting the angular resolution of a lidar device.

8. In paragraph 7, The step of determining each resolution of the inspection target lidar device based on the fitted depth graph and partial average depth for the selected data points is as follows: A step of generating the fitted depth graph by plotting the average depth against the rotation angle; including more, Method for inspecting the angular resolution of a lidar device.

9. In paragraph 8, The step of determining each resolution of the inspection target lidar device based on the fitted depth graph and partial average depth for the selected data points is as follows: A step of calculating the partial average depth for at least some of the above average depths; A step of identifying a pair of data points having the same partial average depth value among the selected data points; For each of the pair of data points, a step of calculating the rotation angle corresponding to the partial average depth having the same value on the fitted depth graph for each of the pair of data points; A step of identifying the number of data points that are sequentially adjacent in the horizontal or vertical direction between the pair of data points; and A step of determining the angular resolution of the inspection target lidar device based on the corresponding rotation angle for the pair of data points and the number of the data points; including more, Method for inspecting the angular resolution of a lidar device.

10. For each resolution inspection device of the lidar device, A test target device support for supporting the test target device; The above inspection target device support part and the rotation adjustment part for rotating the inspection target device; and A processor unit for controlling the operation of the inspection target device and the rotation adjustment unit, and determining each resolution of the inspection target device based on information output by the inspection target device and the rotation adjustment unit; including, Each resolution inspection device of the lidar device.

11. In paragraph 10, The above processor unit, A step of rotating the above-described inspection target lidar device in the azimuth or elevation direction in n steps, and recording a plurality of frames for the target through the inspection target lidar device at each rotation angle of the n steps; A step of selecting at least one data point from among the data points produced by the inspection target lidar device from the frame; and A step of determining each resolution of the inspection target lidar device based on the selected data points; To perform, Each resolution inspection device of the lidar device.

12. In paragraph 11, The step of determining each resolution of the inspection target lidar device based on the selected data points is: A step of determining each resolution of the inspection target lidar device based on the fitted depth graph and partial average depth for the selected data points; including, Each resolution inspection device of the lidar device.

13. In paragraph 11, The above targets include primary and secondary targets, The above main target is positioned so that the optical center and edge of the inspection target lidar device face each other, The sub-target is arranged parallel to the main target and behind the main target in a direction away from the inspection target lidar device. Each resolution inspection device of the lidar device.

14. In paragraph 11, The above-mentioned inspection target lidar device rotates by a preset angle in each of the n steps. Each resolution inspection device of the lidar device.

15. In paragraph 11, The above selected data points are sequentially adjacent in the horizontal or vertical direction, Each resolution inspection device of the lidar device.

16. In paragraph 12, The step of determining each resolution of the inspection target lidar device based on the fitted depth graph and partial average depth for the selected data points is as follows: A step of obtaining depth information of the above data point; including, Each resolution inspection device of the lidar device.

17. In paragraph 16, The step of determining each resolution of the inspection target lidar device based on the fitted depth graph and partial average depth for the selected data points is as follows: A step of calculating an average depth for the data points from the depth information; including more, Each resolution inspection device of the lidar device.

18. In paragraph 17, The step of determining each resolution of the inspection target lidar device based on the fitted depth graph and partial average depth for the selected data points is as follows: A step of generating the fitted depth graph by plotting the average depth against the rotation angle; including more, Each resolution inspection device of the lidar device.

19. In paragraph 18, The step of determining each resolution of the inspection target lidar device based on the fitted depth graph and partial average depth for the selected data points is as follows: A step of calculating the partial average depth for at least some of the above average depths; A step of identifying a pair of data points having the same partial average depth value among the selected data points; For each of the pair of data points, a step of calculating the rotation angle corresponding to the partial average depth having the same value on the fitted depth graph for each of the pair of data points; A step of identifying the number of data points that are sequentially adjacent in the horizontal or vertical direction between the pair of data points; and A step of determining the angular resolution of the inspection target lidar device based on the corresponding rotation angle for the pair of data points and the number of the data points; including more, Each resolution inspection device of the lidar device.

20. In each resolution inspection method of the lidar device, A step of placing at least one target away from the inspection target lidar device; A step of observing a point cloud through the above inspection target lidar device; A step of rotating the inspection target lidar device to shift at least one point and one of the points of a row or column at the edge of the target; A step of acquiring depth information at each rotation angle until at least one of the points of the one point and the row or column deviates from the target; A step of rotating the inspection target lidar device until the same depth information is obtained within the precision of the inspection target lidar device; and A step of obtaining each resolution by considering the number of data points between the same depth information within the precision of the above-mentioned inspection target lidar device; including, Method for inspecting the angular resolution of a lidar device.

21. In the method for inspecting each resolution of the lidar device, A step of placing a lidar device to be inspected on a rotation stage away from at least one target; A step of irradiating light from the inspection target lidar device to the edge area of ​​the target so that a point cloud is observed; A step of rotating the rotation stage according to a preset rotation angle in the azimuth direction or the elevation direction, and recording a plurality of frames for the target through the inspection target lidar device at each rotation angle; A step of obtaining a suitable depth graph at each rotation angle from the above frame; A step of obtaining the depth information included within the tolerance range according to the precision of the inspection target lidar device from the above suitable depth graph and the rotation angle having the depth information included within the tolerance range; and A step of determining the angular resolution of the inspection target lidar device based on the rotation angle having the depth information; including, Method for inspecting the angular resolution of a lidar device.

Images