CN113133319A

CN113133319A - Calibration plate, method and device for testing angular resolution and computer storage medium

Info

Publication number: CN113133319A
Application number: CN201980039525.7A
Authority: CN
Inventors: 卢栋; 水泳; 董帅
Original assignee: SZ DJI Technology Co Ltd
Current assignee: SZ DJI Technology Co Ltd
Priority date: 2019-10-31
Filing date: 2019-10-31
Publication date: 2021-07-16
Also published as: WO2021081963A1

Abstract

A calibration board, a method and a device for testing angular resolution and a computer storage medium are provided. The method for testing the angular resolution comprises the following steps: acquiring point cloud data after a scanning system scans a calibration board, wherein the calibration board comprises at least one marker in at least one direction (S10); from the point cloud data, an angular resolution of the scanning system in the at least one direction is determined (S20). The method uses the calibration plate comprising at least one marker in at least one direction to test the angular resolution of the scanning system, the scheme is simple, has universality and universality, and can obtain accurate angular resolution, thereby providing reliable object parameters for object detection, target tracking and the like of the scanning system.

Description

Calibration plate, method and device for testing angular resolution and computer storage medium

Technical Field

Embodiments of the present invention relate to the field of radar, and more particularly, to a method and apparatus for calibrating a board and testing an angular resolution, and a computer storage medium.

Background

As the cost of scanning systems such as radars and the like decreases, scanning systems have been applied in a wider field. The ability of the angular resolution to characterize the smallest target or smallest angle that the scanning system can detect is one of the most critical indicators of the scanning system, and therefore it is extremely important to accurately measure the angular resolution of the scanning system.

One way is a static test method, i.e. measuring the spot size or the scan interval to indirectly obtain the angular resolution of the scanning system, but this static test method has inaccurate test results and has great limitations.

Disclosure of Invention

The embodiment of the invention provides a calibration plate, a method and a device for testing angular resolution and a computer storage medium, which can conveniently test the angular resolution of a scanning system to obtain an accurate test result.

In a first aspect, there is provided a method of testing the angular resolution of a scanning system, comprising:

acquiring point cloud data after a scanning system scans a calibration plate, wherein the calibration plate comprises at least one marker in at least one direction;

determining an angular resolution of the scanning system in the at least one direction from the point cloud data.

In a second aspect, a calibration plate for testing the angular resolution of a scanning system is provided, the calibration plate comprising at least one marker in at least one direction thereon.

In a third aspect, there is provided an apparatus for testing the angular resolution of a scanning system, comprising: a memory and a processor, wherein,

the memory to store computer instructions;

the processor, configured to invoke the computer instructions, and when executed, configured to perform:

In a fourth aspect, there is provided a scanning system comprising the calibration plate of the second aspect and the apparatus of the third aspect.

In a fifth aspect, a computer-readable storage medium is provided, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the method of the first aspect.

Therefore, the embodiment of the invention uses the calibration plate comprising at least one marker in at least one direction to test the angular resolution of the scanning system, the scheme is simple and universal, and the accurate angular resolution can be obtained, so that reliable object parameters can be provided for object detection, target tracking and the like of the scanning system.

Drawings

The drawings that are required for the embodiments will be briefly described below.

FIG. 1 is a schematic structural diagram of a test system according to an embodiment of the present invention;

FIG. 2 is a schematic view of a calibration plate of an embodiment of the present invention positioned within the FOV;

FIG. 3 is a schematic view of a stripe group of a calibration plate according to an embodiment of the present invention;

FIG. 4 is another schematic view of a stripe group of a calibration plate according to an embodiment of the present invention;

FIGS. 5(a) and (b) are schematic views of a calibration plate comprising two or three-directional sets of stripes according to an embodiment of the present invention;

FIGS. 6(a) and (b) are another schematic illustration of a calibration plate comprising two or three-directional sets of stripes according to an embodiment of the present invention;

FIGS. 7(a) and (b) are schematic views of a calibration plate including a linear type according to an embodiment of the present invention;

fig. 8(a) to (c) are another schematic views of a calibration plate including a linear type according to an embodiment of the present invention;

FIG. 9 is a schematic view of a calibration plate including a plurality of marker blocks according to an embodiment of the present invention;

FIG. 10 is another schematic view of a calibration plate including a plurality of marker blocks according to an embodiment of the present invention;

FIG. 11 is a schematic flow chart of a method of testing the angular resolution of a scanning system in accordance with an embodiment of the present invention;

FIG. 12 is a schematic diagram of point cloud data obtained based on the calibration plate of FIG. 7(b) according to an embodiment of the present invention;

FIG. 13 is a schematic block diagram of an apparatus for testing the angular resolution of a scanning system in accordance with an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described below with reference to the drawings in the embodiments of the present invention.

The laser scanning device (or referred to as a scanning system) can emit detection signals to different directions, so as to acquire data such as depth information and reflectivity information of an object according to echo signals of different directions. In order to ensure the accuracy of the distance measurement of the laser scanning device, the laser scanning device needs to be subjected to a parameter test (or referred to as a performance test) before use, for example, the parameter to be tested includes an angular resolution, that is, the parameter test to be performed before use may include a test of the angular resolution. The method for testing the angular resolution provided in the embodiment of the present invention may be performed by a testing system (also referred to as a calibration system, a testing apparatus, a calibration apparatus, etc.), and the testing system provided in the embodiment of the present invention is first schematically illustrated with reference to fig. 1.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a test system according to an embodiment of the present invention. The test system comprises: testing device 11, movable platform 12.

Wherein, the movable platform 12 and the testing device 11 can establish communication connection through wireless communication connection. In some scenarios, the movable platform 12 and the testing device 11 may also be connected through a wired communication connection. The movable platform 12 may be a movable device such as an unmanned aerial vehicle, an unmanned ship, a movable robot, etc. Referring to fig. 1, the movable platform 12 may include a power system 121, the power system 121 for providing motive force for movement of the movable platform 12.

In some embodiments, the testing device 11 may be mounted on the movable platform 12, for example, the testing device 11 may be a component of the movable platform 12, i.e., the movable platform 12 includes the testing device 11. In other embodiments, the movable platform 12 and the testing device 11 may be independent from each other, that is, the testing device 11 may be spatially independent from the movable platform 12, for example, the testing device 11 is disposed in a cloud server or a mobile terminal (including but not limited to a computer, a mobile phone, etc.), and establishes a communication connection with the movable platform 12 through a wireless communication connection.

The movable platform 12 may carry or be equipped with a laser scanning device. In certain embodiments, the laser scanning device is removably coupled to the movable platform 12. In other embodiments, the laser scanning device may be fixedly disposed on the movable platform 12. Further, in some embodiments, the laser scanning device may include any one or more of a laser radar, an electromagnetic wave radar, a millimeter wave radar, and an ultrasonic radar, which is not limited in this application.

In testing the angular resolution, the embodiment of the present application adopts a calibration board disposed in a field-of-View (FOV) of the laser scanning device, as shown in fig. 2, the FOV 211 of the laser scanning device 21 is indicated by hatching with oblique lines, and the calibration board 22 is located in the FOV 211. The laser scanning device 21 may emit a detection signal onto the calibration plate 22, and the point cloud data may be obtained by collecting echoes having different signal intensities. The testing device 11 can then test the angular resolution of the laser scanning device using the point cloud data.

It should be understood that fig. 2 is merely schematic, and although the laser scanning device 21 in fig. 2 is shown to have one emission source, the actual laser scanning device 21 may have a plurality of sources, and accordingly, the FOV 211 of the laser scanning device 21 may be an area where the FOVs of the respective sources are integrated. Although the FOV 211 of the laser scanner 21 in fig. 2 is shown as a triangular (spatially conical) shape, the FOV 211 of an actual laser scanner 21 may be other shapes, such as a 360 degree scan system having a FOV different from the FOV 211 shown in fig. 2, and not listed here. Although only one calibration board 211 is shown in fig. 2, in practical applications, the number of calibration boards may be multiple.

The calibration plate used in the embodiments of the present invention will be described first, and can be used to test the angular resolution of a laser scanning device (also referred to as a scanning system).

The shape of the calibration plate may be circular, square or any other shape, and as an example, the calibration plate shown in the drawings of the present invention is circular. The calibration plate may have a thickness that is less than the dimensions of the plane. As an example, if the calibration plate is a circular calibration plate, its thickness is smaller than the diameter of the circle, for example, the thickness is equal to one tenth of the diameter, or other values, etc.

Illustratively, the calibration plate may include at least one marker thereon in at least one orientation. The marker is a marker with reflectivity, and when a laser pulse signal emitted by a laser scanning device is applied to the marker, the pulse signal is reflected back.

Wherein, at least one direction may be one direction, or two or more directions. The following first describes the marker in the embodiment of the present invention in terms of the horizontal direction.

As one implementation, the markers are stripe pairs. As can be seen in fig. 3. Fig. 3 shows at least one marker in a horizontal orientation. Where the markers are stripe pairs, the horizontal direction means that the line connecting the centers of the stripe pairs shown is the horizontal direction, as shown by the dashed line in fig. 3.

The pair of stripes comprises two different stripes, where different means that the reflectivities are different, i.e. the pair of stripes comprises a first stripe having a first reflectivity and a second stripe having a second reflectivity. The first stripes may be set as high-reflectance stripes and the second stripes may be set as low-reflectance stripes, that is, the first reflectance may be set to be greater than the second reflectance.

The embodiment of the present invention does not specifically limit the manner of implementing the stripe pair, and the stripe pair may be any one of the following: black and white line pairs, hollow line pairs, color difference line pairs, and the like.

For example, w1 in fig. 3 is a stripe pair, and the stripe pair w1 includes a white stripe and a black stripe, wherein the reflectance of the white stripe is greater than that of the black stripe. That is, the first stripe is a white stripe, and the second stripe is a black stripe.

Alternatively, as an implementation manner, the stripe pairs may be implemented by hollowing, that is, a partial region in the calibration board may be hollowed, for example, the hollowed region may correspond to a black stripe region shown in fig. 3, and the reflectivity of the hollowed portion is lower than that of the white stripe region which is not hollowed.

Alternatively, as another implementation, the stripe pair may also be implemented by stripes with different color differences, for example, the white stripes in fig. 3 are replaced by stripes of a first color, the black stripes in fig. 3 are replaced by stripes of a second color, and the reflectivity of the first color is greater than that of the second color.

For simplicity of description, in the following embodiments of the present invention, the stripe formed by the white stripe and the black stripe as shown in fig. 3 will be described as an example.

In embodiments of the present invention, a stripe may occupy a rectangular area having a length and a width. Referring to fig. 3, the dimension in the vertical direction is shown as long, e.g., L, and the dimension in the horizontal direction is shown as wide, e.g., w 1. Alternatively, the stripes in the same direction may be of equal length, i.e. the stripes in the same direction are of equal length. For example, all the stripes in the horizontal direction shown in fig. 3 have a length L, such as the stripe pair w1 has a length equal to the stripe pair w 2. Alternatively, the length of the stripe pair w1 in fig. 3 may be greater or less than L, the length of the stripe pair w2 may be greater or less than L, and the length of the stripe pair w1 may not be equal to the length of the stripe pair w 2.

The first stripe and the second stripe in the same stripe pair may be equal in width or different in width, that is, in the same stripe pair, the width of the first stripe is equal to the width of the second stripe, or the width of the first stripe is not equal to the width of the second stripe. For example, the width of the white stripes in each stripe pair (e.g., stripe pair w1) in FIG. 3 is equal to the width of the black stripes. For another example, in fig. 4, the width of the white stripe in the stripe pair w5 is not equal to the width of the black stripe, and the width of the white stripe is greater than the width of the black stripe as shown in fig. 4.

For a stripe pair, it may be assumed that the stripe pair comprises a first stripe having a first width and a second stripe having a second width. And the width of the stripe pair may be defined to be equal to the sum of the width of the first stripe and the width of the second stripe, i.e. the width of the stripe pair is equal to the first width plus the second width.

The number of pairs of stripes in the same direction may be at least two. The widths may be equal or unequal for different pairs of stripes in the same direction. For example, taking the horizontal direction as an example, assuming that the stripe pair in the horizontal direction includes a first stripe pair and a second stripe pair, the width of the first stripe pair may be equal to or not equal to the width of the second stripe pair. Referring to fig. 3, the width of the stripe pair w1 is not equal to the width of the stripe pair w2, and the width of the stripe pair w4 is equal to the width of the stripe pair w 41.

Alternatively, the width of the stripe pairs may be from large to small or from small to large. Referring to fig. 3, the width is gradually reduced from stripe pair w1 to stripe pair w 4. Likewise, the width of the stripe pairs decreases progressively from left to right in fig. 4.

The number of stripe pairs having equal width may be one or more for the same direction. For the stripe pairs in the first direction, the widths of some stripe pairs are equal, and the widths of some stripe pairs are not equal. For example, the widths of the 1 st to N1 th stripe pairs are all W1, the widths of the N1+1 th to N1+ N2 th stripe pairs are all W2, and W1 is not equal to W2. The number of stripe pairs with equal width may be 1, for example, N1 ═ 1 or N2 ═ 1; alternatively, the number of stripe pairs of equal width may be plural, for example N1>1 or N2> 1. Referring to fig. 3, N1 is 3, i.e., the widths of the 1 st to 3 rd stripe pairs are equal, and are all w 1. N2 is 3, i.e. the widths of the 4 th to 6 th stripe pairs are equal, all w 2. Referring to fig. 4, N1-N2-1, that is, the width of the 1 st stripe pair is not equal to the width of the 2 nd stripe pair.

The widths of the first stripes may be equal or unequal for different stripe pairs. For example, the width of the first stripe in the first stripe pair is equal to or unequal to the width of the first stripe in the second stripe pair. Referring to fig. 3, the width of the white stripe in the stripe pair w1 is not equal to the width of the white stripe in the stripe pair w 2. Referring to fig. 4, the width of the white stripe in the stripe pair w5 is equal to the width of the white stripe in the stripe pair w 6.

Optionally, the width of at least one of the fringe pairs in a single direction may include a spot size or scan spacing of the laser scanning device at a first distance from the calibration plate.

For ease of description, at least one marker (i.e., at least one stripe pair) in the same direction is assigned to the same stripe group. Each stripe group comprises at least one stripe element, each stripe element comprises at least one stripe pair, and the width of the stripe pair in each stripe element in the same stripe group is from large to small or from small to large.

Taking the horizontal direction as an example, all the stripe pairs in the horizontal direction constitute a stripe group, and as shown in fig. 3 or 4, an example of a stripe group corresponding to the horizontal direction is shown. A stripe group may comprise several stripe elements. The stripe group as shown in fig. 3 includes 4 stripe elements, respectively designated twy11, twy12, twy13 and twy 14. The stripe group as shown in fig. 4 includes 5 stripe elements, respectively designated twy21, twy22, twy23, twy24 and twy 25.

The stripe element may include at least one stripe pair. As in fig. 3, each stripe element in twy11, twy12, and twy13 includes 3 stripe pairs and twy14 includes 5 stripe pairs. As in fig. 4, each stripe element of twy21, twy22, twy23, twy24, and twy25 includes 1 stripe pair.

The widths of the stripe pairs in the same stripe element may be equal, and referring to fig. 3, the widths of 3 stripe pairs in twy11 are all w1, the widths of 3 stripe pairs in twy12 are all w2, the widths of 3 stripe pairs in twy13 are all w3, and the widths of 5 stripe pairs in twy14 are all w 4.

For example, the stripe unit may include a plurality of stripe pairs, and each stripe pair in the same stripe unit may be the same, that is, each stripe pair has an equal width, and the widths of the first stripes included in each stripe pair are also equal. For example, the widths of the 3 stripe pairs in twy11 in fig. 3 are all w1, and the widths of the first stripe and the second stripe in the 3 stripe pairs are all w11 and w12 (not shown in fig. 3).

That is, several adjacent identical stripe pairs may be classified as one stripe element. The same stripe pair refers to: the width of the stripe pairs is equal.

For different stripe elements in the same stripe group, the width of the stripe pair can be from large to small or from small to large. Assuming that one stripe group is in the horizontal direction, the stripe pairs are from large to small or from small to large along the horizontal direction. Referring to fig. 3, the width of the stripe pair is from large to small along the left-to-right direction shown in fig. 3, i.e., w1> w2> w3> w 4; it will be understood that the width of the stripe pairs increases from smaller to larger in the right-to-left direction as viewed in fig. 3.

As an example, the width of the first stripe in a stripe pair may be equal to the width of the second stripe, and as shown in fig. 3, the width of the first stripe in each stripe pair is equal to the width of the second stripe. For example, the width of the stripe pairs in twy11 is w1, and the width of the first stripe and the width of the second stripe are w 1/2. As further shown in fig. 4, the width of the first stripe in twy12 is greater than the width of the second stripe.

As another example, the width of the first stripe in a stripe pair may not be equal to the width of the second stripe, as shown in fig. 4, and the width of the first stripe in each of twy22 through twy25 is not equal to the width of the second stripe.

Optionally, the width of the first stripe in all stripe pairs within the same stripe group is equal. As shown in fig. 4, 5 stripe pairs are shown, the first stripe in each stripe pair having a width equal to w 0. It should be appreciated that for simplicity of illustration, only the first stripe of the first stripe pair is shown in fig. 4 as having a width w 0.

Additionally, it should be noted that fig. 3 and 4 are merely illustrative of groups of stripes and should not be construed as limiting, and groups of stripes may be in any form within the scope of embodiments of the present invention.

The schematic diagram of the stripe pairs is described above with reference to fig. 3 and 4, taking only the horizontal direction as an example, the calibration board includes stripe pairs in at least one direction, and the at least one direction may include: one or more of horizontal direction, vertical direction and inclined direction. As an example, it may only include the horizontal direction or only the vertical direction, for example, fig. 3 and 4 only include the stripe pairs in the horizontal direction. As another example, horizontal and vertical directions may be included, for example, stripe pairs in the horizontal and vertical directions are included as shown in fig. 5(a) and 6 (a). As still another example, horizontal, vertical and diagonal directions may be included, for example, stripe pairs in the horizontal, vertical and diagonal directions are included as shown in fig. 5(b) and 6 (b).

It should be noted that the horizontal direction and the vertical direction refer to two orthogonal directions. Wherein, the horizontal direction can be parallel to the ground, and the vertical direction is vertical to the ground; alternatively, the horizontal direction is at an angle to the ground and the vertical direction is orthogonal to the horizontal direction. Specifically, the angle between the ground and the ground is related to the placement position of the calibration board, for example, rotating the calibration board can change the angle between at least one direction and the ground. The horizontal direction in the embodiment of the present invention means: one of the at least one direction can be made a direction parallel to the ground by rotating the calibration plate.

The inclined direction may refer to a direction having a preset angle with the horizontal direction. For example, the preset angle may be 30 °, 45 °, 60 °, or other angles. The oblique direction as shown in fig. 5(b) and 6(b) is a direction at 45 ° from the horizontal direction.

It is understood that the at least one direction may comprise more directions, such as 4 directions: horizontal, vertical, 45 ° oblique, and 60 ° oblique, and so on.

As described above, at least one marker (i.e., at least one stripe pair) in the same direction is classified into the same stripe group, and then at least one marker (i.e., at least one stripe pair) in at least one direction corresponds to at least one stripe group. In the embodiment of the present invention, different stripe groups may have the same or different patterns. The pattern of the group of stripes may comprise at least one of: the number of stripe cells, the number of stripe pairs in a single stripe cell, the width of a stripe pair, the width of the first stripe and/or the second stripe within a stripe pair, and so on.

Alternatively, the pattern of different groups of stripes may be the same. For example, assuming that the at least one direction includes a first direction and a second direction, a first stripe group of the first direction and a second stripe group of the second direction may be in the same pattern, for example, the first stripe group may be rotated to the second direction by a certain angle as a whole, so that the pattern of the second stripe group is the same as that of the first stripe group. Referring to fig. 5(a), 5(b), 6(a) and 6(b), the pattern of the stripe groups in the horizontal direction and the vertical direction is the same, and it can be considered that the stripe groups in the horizontal direction are rotated by 90 degrees and then translated to be not overlapped with the stripe groups in the horizontal direction. Specifically, the horizontal direction stripe group in fig. 5(a) and 5(b) is the stripe group shown in fig. 3, and the horizontal direction stripe group in fig. 6(a) and 6(b) is the stripe group shown in fig. 4.

Alternatively, the pattern of different groups of stripes may be different. Referring to fig. 5(b) and 6(b), the pattern of the stripe groups in the oblique direction is different from that in the horizontal direction (or vertical direction). Specifically, the number of stripe elements of the stripe group in the oblique direction is different from that of the stripe group in the horizontal direction (or the vertical direction), the width of a stripe pair in the stripe elements, and the like. Specifically, the horizontal stripe group in fig. 5(b) is the stripe group shown in fig. 3, and the oblique stripe group is obtained after the stripe group in fig. 4 is rotated by 45 degrees, as can be seen from fig. 3 and 4, the horizontal stripe group in fig. 5(b) includes 4 stripe elements, and the oblique stripe group in fig. 5(b) includes 5 stripe elements; and the stripe cells in the horizontal direction stripe group in fig. 5(b) include 3 or 5 stripe pairs, and the stripe cells in the diagonal direction stripe group in fig. 5(b) include 1 stripe pair; and so on. It can be similarly seen with respect to fig. 6(b) that the pattern of the stripe groups in the oblique direction is different from that of the stripe groups in the horizontal direction (or the vertical direction), and will not be described again here.

The embodiment of the invention does not limit the position relation between different stripe groups corresponding to different directions. For example, two groups of stripes in two different directions may have a larger or smaller spatial separation between them.

Illustratively, the at least one direction coincides with a scanning direction of the scanning system. For example, if the scanning direction includes a horizontal direction, at least one direction also includes the horizontal direction.

Optionally, the at least one direction comprises a scanning direction of the scanning system. As an example, if the scanning direction is a horizontal direction, the at least one direction includes a horizontal direction, and optionally may further include a vertical direction and/or an oblique direction, and the like.

In addition, if the angular resolution of the scanning system in a certain scanning direction (for example, the horizontal direction) is desired to be tested, at least one stripe pair in the horizontal direction should be included on the calibration board, but at least one stripe pair in the vertical direction and/or the oblique direction may also be included on the calibration board.

To test the angular resolution of the scanning system in the horizontal direction, the angular resolution of the scanning system in the horizontal direction may be determined based on at least one fringe pair in the horizontal direction on the calibration plate, in which case at least one fringe pair in the other direction on the calibration plate may be ignored.

In addition, if the angular resolution of the scanning system in two scanning directions (e.g., horizontal and vertical) is desired to be tested, at least one stripe pair in the horizontal direction and at least one stripe pair in the vertical direction should be included on the calibration board, although at least one stripe pair in the oblique direction may also be included on the calibration board. Alternatively, a first calibration plate comprising at least one fringe pair in the horizontal direction may be used to determine the angular resolution of the scanning system in the horizontal direction, and then a second calibration plate comprising at least one fringe pair in the vertical direction may be used to determine the angular resolution of the scanning system in the vertical direction.

In addition, if the angular resolution of the scanning system in three scanning directions (i.e., horizontal, vertical, diagonal) is desired to be tested, then similarly, the calibration plate including at least one fringe pair in three directions may be used for determination, or the calibration plates of at least one fringe pair in a corresponding single direction may be used for determination, respectively, or the calibration plate including at least one fringe pair in a single direction and the calibration plate including at least one fringe pair in the other two directions may be used for determination, respectively.

Therefore, the calibration board provided by the embodiments of the present invention includes at least one stripe pair in at least one direction, and can be used for testing the angular resolution of the scanning system in at least one direction, and in particular, can be used for testing the scanning systems with different angular resolutions by controlling the widths of the stripe pair and the widths of the first stripe and the second stripe therein, and has universality.

As another implementation, the marker may be linear, in addition to being a stripe. The line type is a line type having reflectivity, and when a laser pulse signal emitted by the laser scanning device hits the line type, the pulse signal is reflected back. The line type will be described below with reference to fig. 7 and 8.

Illustratively, the line shape may have a certain width, and the embodiment of the present invention does not limit the specific value of the width. The width may be a very small value, for example a few millimetres or less than 1 millimetre, i.e. the line is a thin line. Alternatively, the width may be a value on the order of centimeters, for example. Referring to fig. 7, line types in the horizontal direction and the vertical direction are included in each of 7(a) and 7(b), and the width of the line type in 7(a) is smaller than the width of the line type in 7 (b).

It should be understood that although the horizontal line type and the vertical line type in fig. 7(a) have the same width, the present invention is not limited thereto, and the line types in different directions may have different widths. In addition, although fig. 7(a) includes a line type in the horizontal direction and the vertical direction, the present invention is not limited thereto, and may include only a line type in one direction, or may include three line types in the horizontal direction, the vertical direction, and the oblique direction. For example, referring to fig. 8, fig. 8(a) includes a line type in a vertical direction, fig. 8(b) includes a line type in a horizontal direction and a vertical direction, and fig. 8(c) includes a line type in a horizontal direction, a vertical direction, and an oblique direction.

The inclined direction may be a direction forming a predetermined angle with the horizontal direction. For example, the preset angle may be 30 °, 45 °, 60 °, or other angles. The oblique direction as shown in fig. 8(c) is a direction at 45 ° to the horizontal direction.

For example, the embodiment of the present invention does not limit the specific implementation manner of the line type, and may be any one of a thin line, a cardboard, a metal strip, a total reflection sheet, and the like.

Illustratively, the line type may form a lattice shape of a rectangle, a square, or a triangle. Referring to fig. 8, the line type in fig. 8(a) forms a rectangular lattice, the line type in fig. 8(b) forms a square lattice, and the line type in fig. 8(c) forms a square and triangular lattice.

It should be noted that fig. 8 shows only an example, and the calibration plate may include only a linear type in one direction (e.g., horizontal direction), or may include a linear type in two or more directions. The number of lines in a certain direction may be 1 or more. For example, fig. 8(a) includes a plurality of vertical line types (4 line types). Fig. 8(b) includes horizontal and vertical line types, the number of which is plural (3), and the number of which is also plural (3). Fig. 8(c) includes horizontal, vertical, and oblique line types, the number of the horizontal line types being plural (3), the number of the vertical line types also being plural (3), and the number of the oblique line types being 1.

Illustratively, the at least one direction is perpendicular to a scanning direction of the scanning system. As an example, if the scanning direction includes a horizontal direction, at least one direction includes a vertical direction.

Optionally, the at least one direction comprises a direction perpendicular to a scanning direction of the scanning system. As an example, if the scanning direction is a horizontal direction, at least one direction includes a vertical direction, and optionally may also include a horizontal direction and/or an oblique direction, and the like.

In addition, if it is desired to test the angular resolution of the scanning system in a certain scanning direction (for example, the horizontal direction), at least one line in the vertical direction should be included on the calibration board, and at least one line in the horizontal direction and/or the oblique direction may also be included on the calibration board.

To test the angular resolution of the scanning system in the horizontal direction, the angular resolution of the scanning system in the horizontal direction may be determined based on at least one line type in the vertical direction on the calibration plate, in which case at least one line type in the other direction on the calibration plate may be ignored.

In addition, if it is desired to test the angular resolution of the scanning system in two scanning directions (e.g., horizontal and vertical), then at least one line type in the vertical direction and at least one line type in the horizontal direction should be included on the calibration board, although at least one line type in the oblique direction may also be included on the calibration board. Alternatively, a first calibration plate comprising at least one linear pattern in the vertical direction may be used to determine the angular resolution of the scanning system in the horizontal direction, and then a second calibration plate comprising at least one linear pattern in the horizontal direction may be used to determine the angular resolution of the scanning system in the vertical direction.

In addition, if it is desired to test the angular resolution of the scanning system in three scanning directions (i.e., horizontal direction, vertical direction, oblique direction), similarly, it may be determined using a calibration board including at least one line type of three directions respectively perpendicular to the three scanning directions, or it may be determined respectively using a calibration board of at least one line type of a direction perpendicular to the corresponding single scanning direction, or it may be determined respectively using a calibration board including at least one line type of a direction perpendicular to the single scanning direction, and a calibration board including at least one line type of a direction respectively perpendicular to the other two scanning directions.

It can thus be seen that embodiments of the present invention provide a calibration plate comprising at least one line type in at least one direction that can be used to test the angular resolution of a scanning system in a perpendicular direction to the at least one direction.

In addition, the calibration plate may include a plurality of marker blocks, each marker block being located differently on the calibration plate. Referring to fig. 9 and 10, the illustrated calibration plate is circular, and the calibration plate in fig. 9 includes 11 marking blocks, which are sequentially numbered 1 to 11, and the calibration plate in fig. 10 includes 5 marking blocks, which are sequentially numbered 1 to 5. It should be noted that although the plurality of mark blocks in fig. 9 and 10 are arranged more regularly, and are centrosymmetric, the position of the mark block may be arbitrary in practice, and the present invention is not limited thereto. Although the calibration plate in fig. 9 and 10 is circular, it may be other shapes such as rectangular, hexagonal, other regular or irregular shapes, etc.

Each marker block may comprise at least one marker in at least one direction. Reference may be made to the detailed description of the previous embodiments with respect to at least one marker in at least one direction. For example, the marker may be a stripe pair, and the stripe pair included in the marker block may be any one of the stripe pairs shown in fig. 3, 4, 5(a) or (b), and 6(a) or (b). As another example, the marker may be a linear type, and the linear type included in the marker block may be any of the above-described fig. 7(a) or (b), and fig. 8(a) to (c).

It should be noted that the pattern of markers on different marker blocks on the same calibration plate may be the same or different. Such as direction, number of markers, width of markers, etc. For example, the mark block a includes a horizontal stripe group, and the mark block B includes a horizontal and vertical stripe group. As another example, the mark block a includes a horizontal stripe group, and the mark block B includes a vertical line type.

The calibration plate, in particular the shape of the calibration plate, the at least one marker in at least one direction comprised by the calibration plate, is described above in connection with the embodiments of fig. 3 to 10. The calibration plate may be used to test the angular resolution of the scanning system. The process of the method of testing the angular resolution of a scanning system will be described below in conjunction with specific embodiments.

FIG. 11 is a schematic flow chart of a method for testing the angular resolution of a scanning system according to an embodiment of the present invention. The method can comprise the following steps:

s10, point cloud data after the scanning system scans a calibration board is obtained, wherein the calibration board comprises at least one marker in at least one direction;

s20, determining the angular resolution of the scanning system in the at least one direction according to the point cloud data.

Wherein the scanning system may emit a beam, the scanning system may be, for example, a radar, such as a lidar or an electromagnetic wave radar, etc.

Prior to S10, the calibration plate may be placed in the direction in which the scanning system transmit beam is traveling, that is, so that the scanning system transmit beam reaches the calibration plate. In particular, the calibration plate may be placed within the field of view (FOV) of the scanning system. Illustratively, the transmit beam may be perpendicular to the calibration plate, e.g., the center of the transmit beam is aligned with the center normal of the calibration plate. Or, illustratively, the transmit beam may be at an angle to the calibration plate, e.g., the center of the transmit beam is at an angle to the normal of the center of the calibration plate.

In the embodiment of the invention, the relative position relationship between the scanning system and the calibration plate can be adjusted by moving the scanning system or moving the calibration plate. Wherein the manner of moving the scanning system is more space-saving and easier to implement.

The relative positional relationship includes an angle and/or a distance. For example, the scanning system may be moved or the calibration plate may be moved such that the angle between the transmit beam of the scanning system and the calibration plate changes, and/or such that the distance between the scanning system and the center of the calibration plate changes. As an example, the calibration plate may be positioned at a particular location of the FOV of the scanning system by moving the scanning system or moving the calibration plate.

As described in connection with fig. 9 to 10, the calibration plate may include a plurality of marking blocks. Then in fig. 11: the angular resolution can be derived based on any of the marked blocks. Alternatively, the angular resolution may be derived based on all or part of the plurality of marker blocks. For example, an average of a plurality of angular resolutions obtained based on the plurality of marker blocks may be determined as the angular resolution of the scanning system. Alternatively, for example, a weighted sum of a plurality of angular resolutions obtained based on a plurality of marker blocks may be determined as the angular resolution of the scanning system, and the weight may be set in advance according to the positions of the marker blocks.

Thus, by using a calibration plate including a plurality of marking blocks, it is possible to consider a systematic error as well as a random error of the scanning system, so that the test result is more accurate. In addition, for the scanning system with non-fixed angular resolution, the dynamic angular resolution of the scanning system can be determined based on the plurality of marking blocks, so that accurate test results can be obtained.

In an embodiment of the invention, the angular resolution of the scanning system in at least one direction or in a direction perpendicular to the at least one direction may be determined based on a calibration plate comprising at least one marker in the at least one direction. That is, S20 may determine the angular resolution of the scanning system in the at least one direction or in a direction perpendicular to the at least one direction from the point cloud data.

For example, to test the angular resolution of the scanning system in the horizontal direction, the angular resolution of the scanning system in the horizontal direction may be determined based on at least one stripe pair in the horizontal direction or at least one line type in the vertical direction on the calibration board. If a plurality of marking blocks are included on the calibration plate, the angular resolution in the horizontal direction can be obtained on a per marking block basis, and then the average value can be calculated as the angular resolution of the scanning system in the horizontal direction.

The procedure of the method for calculating the angular resolution of a direction based on at least one stripe pair of the direction in a mark block and the procedure of the method for calculating the angular resolution of a perpendicular direction of a direction based on at least one line type pair of the direction in a mark block will be explained in detail in the following embodiments.

The calibration plate used in testing the angular resolution of the scanning system may be the calibration plate described in the previous embodiments, wherein the markers may be stripe pairs or linear, as will be described separately below.

In one implementation, the markers are pairs of stripes, such that the calibration plate may be, for example, as described above in connection with fig. 3-6.

In testing the angular resolution of the scanning system, a suitable calibration plate may be selected. Illustratively, the width of at least one fringe pair in the single direction on the calibration plate comprises a spot size or scan spacing of the scanning system at a first distance between the scanning system and the calibration plate. The length L of the stripe group is at least larger than the length of the corresponding direction of the light spot at the position.

Specifically, for example, in a certain direction (e.g., a horizontal direction), an angular resolution of the scanning system in the horizontal direction may be estimated, for example, the angular resolution of the batch marks associated with the scanning system may be estimated, and then the spot size at the first distance may be determined according to the estimated angular resolution. And, the range of the width of the second stripe in the horizontal stripe pair on the selected calibration plate should include the spot size. The length of the stripe group is at least larger than the length of the corresponding direction of the light spot at the position. For example, if the calculated spot size is axb (width x length), then the range of the width of the second stripe should include a. Referring to fig. 3, wherein the second stripe ranges from w4/2 to w1/2, specifically, four values of w4/2, w3/2, w2/2, w1/2, and w4/2< a < w 1/2. The stripe group length L > b.

The distance between the scanning system and the calibration plate may, in turn, be adjusted based on the estimated angular resolution of the scanning system and the extent of the width of the second stripe of the pair of stripes on the calibration plate such that the spot size at the first distance is within the extent of the width of the second stripe.

Exemplarily, in S20, a minimum width of the resolvable second stripe in a first direction of the at least one direction may be determined from the point cloud data; determining an angular resolution of the scanning system in the first direction according to the minimum width of the resolvable second stripe.

Because the optical signal of the emission beam of the scanning system has a strong signal in the high-reflectivity line and a weak signal in the low-reflectivity line, the acquired point cloud data can present a clear fringe point cloud image, wherein the interval of the fringes which can be just clearly resolved is the resolution limit under the distance, namely the minimum width of the resolvable second fringe.

Wherein determining a minimum width of the resolvable second striations in the first direction from the point cloud data may comprise: and determining the minimum width of the resolvable second stripes in the first direction based on the point cloud data according to preset visibility.

For example, the resolvable condition of the stripes may be preset, i.e. a visibility (e.g. 50% or other value) is defined, and then the minimum width of the resolvable second stripes is determined based on the visibility. Specifically, in the point cloud data, the minimum width of the distinguishable second stripe may be found based on a variation rule of the point cloud density along the first direction. Where visibility can be understood as the proportion of the point cloud density falling to a maximum value, e.g. 50% means that the point cloud density falls to half of the maximum value. Wherein, the visibility can be set and updated according to the attribute of the scanning system.

Wherein determining the angular resolution of the scanning system in the first direction according to the minimum width of the resolvable second stripe may comprise: determining a ratio of a minimum width of the resolvable second stripe in the first direction to a distance between the scanning system and a location of the minimum width second stripe as an angular resolution of the scanning system in the first direction.

For example, assuming that the minimum width of the resolvable second stripe is denoted as Δ d and the distance between the scanning system and the second stripe of the minimum width is L, the angular resolution may be determined as δ ═ Δ d/L.

The distance between the scanning system and the second stripe of the minimum width may be a distance between the scanning system and a center of the second stripe of the minimum width or a distance between the scanning system and a mark block where the second stripe of the minimum width is located.

In this way, the angular resolution of the scanning system in the first direction may be obtained, and similarly, the angular resolution of the scanning system in the other directions may be obtained, which will not be described herein again.

In another implementation, the tag is linear, such that the calibration plate may be, for example, as described above in connection with fig. 7-8.

Exemplarily, in S20, a point cloud width along a vertical direction of the line type on the line type may be determined according to the point cloud data; and determining the angular resolution of the scanning system in the vertical direction of the line type according to the point cloud width.

Referring to fig. 12, there is shown a point cloud obtained using the calibration plate of fig. 7(b), wherein the width of the point cloud along the vertical direction on a line in the horizontal direction, i.e., the width of the two rectangles "left" and "right" in fig. 12 (the dimension in the vertical direction), can be obtained, and the angular resolution of the scanning system in the vertical direction can be determined based thereon. In this case, the width of the point cloud along the horizontal direction on the vertical line, such as the widths of the two rectangles "up" and "down" (the size in the horizontal direction) in fig. 12, can be obtained, and the angular resolution of the scanning system in the horizontal direction can be determined based on the width. It should be appreciated that if only the angular resolution of the scanning system in the horizontal direction needs to be tested, then only the width of the point cloud in the horizontal direction on the vertical line type can be determined, and the point cloud in the horizontal line type can be ignored.

Wherein determining the angular resolution of the scanning system in the vertical direction of the line type according to the point cloud width may include: calculating the difference between the width of the point cloud and the width of the line type; determining a ratio of the difference to a distance between the scanning system and a location of the line type as an angular resolution of the scanning system in a vertical direction of the line type.

It will be appreciated that if the width of the line pattern is small, much smaller than the spot width, e.g. the ratio of the width of the line pattern to the spot width is smaller than a predetermined value (e.g. 0.01), the width of the line pattern can be ignored and the ratio of the point cloud width to the distance between the scanning system and the position of the line pattern is determined as the angular resolution of the scanning system in the vertical direction of the line pattern.

Further alternatively, a plurality of calibration plates may be used in S10. As one implementation, one or more of the plurality of calibration plates may be used to determine the angular resolution in the first direction, while another one or more of the plurality of calibration plates may be used to determine the angular resolution in the second direction. As another implementation, each calibration plate may be used to determine the angular resolution in at least one direction included on the calibration plate, and then the angular resolution in a certain direction obtained based on the calibration plates may be averaged or weighted and summed to obtain the angular resolution of the scanning system in a certain direction.

In the embodiment of the invention, the angular resolution of the scanning system is determined by setting a plurality of marking blocks on the calibration plate or by a plurality of calibration plates, so that the accuracy of the test can be improved.

Therefore, in the embodiment of the invention, the calibration board including at least one marker in at least one direction is used for testing the angular resolution of the scanning system, the scheme is simple and universal, and the accurate angular resolution can be obtained, so that reliable object parameters can be provided for object detection, target tracking and the like of the scanning system.

FIG. 13 is another schematic block diagram of an apparatus for testing the angular resolution of a scanning system in accordance with an embodiment of the present invention. The apparatus shown in fig. 13 includes a processor 210 and a memory 220. The memory 220 stores computer instructions that, when executed by the processor 210, cause the processor 210 to perform the steps of: acquiring point cloud data after a scanning system scans a calibration plate, wherein the calibration plate comprises at least one marker in at least one direction; determining an angular resolution of the scanning system in the at least one direction from the point cloud data.

Optionally, in some embodiments, the processor 210 may be specifically configured to: determining a minimum width of resolvable second stripes in a first direction of the at least one direction from the point cloud data; determining an angular resolution of the scanning system in the first direction according to the minimum width of the resolvable second stripe.

Optionally, in some embodiments, the processor 210 may be specifically configured to: and determining the minimum width of the resolvable second stripes in the first direction based on the point cloud data according to preset visibility.

Optionally, in some embodiments, the processor 210 may be specifically configured to: determining a ratio of a minimum width of the resolvable second stripe in the first direction to a distance between the scanning system and a location of the minimum width second stripe as an angular resolution of the scanning system in the first direction.

As another implementation, the tag is linear, such that the calibration plate may be, for example, as described above in connection with fig. 7-8.

Optionally, in some embodiments, the processor 210 may be specifically configured to: determining a point cloud width on the line type along a vertical direction of the line type according to the point cloud data; and determining the angular resolution of the scanning system in the vertical direction of the line type according to the point cloud width.

Optionally, in some embodiments, the processor 210 may be specifically configured to: calculating the difference between the width of the point cloud and the width of the line type; determining a ratio of the difference to a distance between the scanning system and a location of the line type as an angular resolution of the scanning system in a vertical direction of the line type.

It should be understood that the apparatus for testing the angular resolution of a scanning system may be implemented as a testing system or calibration device as shown in fig. 1, or may be any of various devices capable of implementing the method of the embodiments of the present invention, such as a movable platform, a computer, a tablet computer, a smart phone, etc.

The apparatus shown in FIG. 13 can be used to implement the method for testing the angular resolution of a scanning system as described above with reference to FIG. 11.

An embodiment of the present invention further provides a scanning system, including: the apparatus shown in fig. 13, along with a calibration plate, can be used to test the angular resolution of a scanning system. Wherein the calibration plate may be the calibration plate described above in connection with fig. 3 to 10.

An embodiment of the present invention further provides a test system, including: the apparatus, calibration plate, and scanning system shown in fig. 13 can be used to test the angular resolution of the scanning system. Wherein the calibration plate may be the calibration plate described above in connection with fig. 3 to 10.

Embodiments of the present invention also provide a computer storage medium having a computer program stored thereon, where the computer program is executed by a computer or a processor, so that the computer or the processor executes the method for testing the angular resolution of a scanning system provided in the above method embodiments.

In particular, the computer program, when executed by a computer or processor, causes: acquiring point cloud data after a scanning system scans a calibration plate, wherein the calibration plate comprises at least one marker in at least one direction; determining an angular resolution of the scanning system in the at least one direction from the point cloud data.

Embodiments of the present invention also provide a computer program or a computer program product comprising instructions, which when executed by a computer, cause the computer to perform the method for testing the angular resolution of a scanning system provided in the above method embodiments.

Specifically, the instructions, when executed by the computer, cause the computer to perform: acquiring point cloud data after a scanning system scans a calibration plate, wherein the calibration plate comprises at least one marker in at least one direction; determining an angular resolution of the scanning system in the at least one direction from the point cloud data.

Therefore, in the embodiment of the invention, the calibration board including at least one marker in at least one direction is used for testing the angular resolution of the scanning system, the scheme is simple and universal, and the accurate angular resolution can be obtained, so that reliable object parameters can be provided for object detection, target tracking and the like of the scanning system. The calibration board can comprise at least one stripe pair in at least one direction, can be used for testing the angular resolution of the scanning system in at least one direction, can be used for testing the scanning systems with different angular resolutions by controlling the width of the stripe pair and the width of the first stripe and the second stripe, and has universality, easy portability and large-scale implementation.

In the above embodiments, all or part of the implementation may be realized by software, hardware, firmware or any other arbitrary combination. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the invention to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored on a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website, computer, server, or data center to another website, computer, server, or data center via wire (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that incorporates one or more of the available media. The usable medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a magnetic tape), an optical medium (e.g., a Digital Video Disk (DVD)), or a semiconductor medium (e.g., a Solid State Disk (SSD)), among others.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processor, or each unit may exist alone physically, or two or more units are integrated into one unit.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

A method of testing the angular resolution of a scanning system, comprising:

acquiring point cloud data after a scanning system scans a calibration plate, wherein the calibration plate comprises at least one marker in at least one direction;

determining an angular resolution of the scanning system in the at least one direction from the point cloud data.
The method of claim 1, wherein the marker is a pair of stripes comprising a first stripe having a first reflectivity and a second stripe having a second reflectivity, and the first reflectivity is greater than the second reflectivity.
The method of claim 2, wherein the stripe pairs in a single one of the at least one direction comprise at least two.
The method of claim 2 or 3, wherein the width of the stripe pairs in a single one of the at least one direction comprises at least one.
The method of claim 4, wherein the width of the stripe pairs in the single direction is from large to small or from small to large.
The method of claim 4 or 5, wherein the pairs of stripes of the same width in the single direction comprise one or more.
The method of any of claims 4 to 6, wherein the width of at least one fringe pair in the single direction comprises a spot size or scan spacing of the scanning system at a first distance between the scanning system and the calibration plate.
The method according to any one of claims 2 to 7, wherein the at least one marker belongs to at least one stripe group, each stripe group corresponds to one direction of the at least one direction, each stripe group comprises at least one stripe element, each stripe element comprises at least one stripe pair, and the width of the stripe pairs in the stripe elements in the same stripe group is from large to small or from small to large.
The method of claim 8, wherein each stripe element comprises three stripe pairs.
A method according to claim 8 or 9, wherein the width of the stripe pairs in the same stripe element is equal.
The method of any of claims 8 to 10, wherein the width of the pair of stripes is the sum of the width of the first stripe and the width of the second stripe.
The method of any of claims 8 to 11, wherein the width of the first stripe of the stripe pair is equal to the width of the second stripe, or wherein the width of the first stripe of the stripe pair is not equal to the width of the second stripe.
A method according to any one of claims 8 to 11, wherein the width of the first stripe in each stripe element within a same stripe group is equal.
The method according to any of claims 8 to 13, wherein different groups of stripes comprise equal or unequal numbers of stripe elements.
The method according to any one of claims 2 to 14, wherein the pair of stripes comprises any one of: black and white line pairs, hollow line pairs and color difference line pairs.
The method of any of claims 2 to 15, wherein said determining an angular resolution of the scanning system in the at least one direction from the point cloud data comprises:

determining a minimum width of resolvable second stripes in a first direction of the at least one direction from the point cloud data;

determining an angular resolution of the scanning system in the first direction according to the minimum width of the resolvable second stripe.
The method of claim 16, wherein determining a minimum width of resolvable second stripes in the first direction from the point cloud data comprises:

and determining the minimum width of the resolvable second stripes in the first direction based on the point cloud data according to preset visibility.
The method of claim 16 or 17, wherein determining the angular resolution of the scanning system in the first direction according to the minimum width of the resolvable second stripe comprises:

determining a ratio of a minimum width of the resolvable second stripe in the first direction to a distance between the scanning system and a location of the minimum width second stripe as an angular resolution of the scanning system in the first direction.
The method of any one of claims 2 to 18, wherein the at least one direction coincides with a scanning direction of the scanning system.
The method of claim 1, wherein the marker comprises a linear form.
The method of claim 20, wherein the wire form forms a lattice shape of a rectangle, square, or triangle.
The method according to claim 20 or 21, wherein the line type comprises any one of: fine lines, paper boards, metal strips, total reflection sheets.
The method of any of claims 20 to 22, wherein said determining an angular resolution of the scanning system in the at least one direction from the point cloud data comprises:

determining a point cloud width on the line type along a vertical direction of the line type according to the point cloud data;

and determining the angular resolution of the scanning system in the vertical direction of the line type according to the point cloud width.
The method of claim 23, wherein determining the angular resolution of the scanning system in the vertical direction of the line shape from the point cloud width comprises:

calculating the difference between the width of the point cloud and the width of the line type;

determining a ratio of the difference to a distance between the scanning system and a location of the line type as an angular resolution of the scanning system in a vertical direction of the line type.
The method of any one of claims 20 to 24, wherein the at least one direction is perpendicular to a scanning direction of the scanning system.
The method according to any one of claims 1 to 25, wherein the at least one direction comprises: one or more of horizontal direction, vertical direction and inclined direction.
The method of claim 26, wherein the oblique direction is a direction at a preset angle to the horizontal direction.
The method of any of claims 1 to 27, wherein the calibration plate is positioned within a field of view of the scanning system, and further comprising, prior to scanning:

adjusting a relative positional relationship between the scanning system and the calibration plate by moving the scanning system or moving the calibration plate.
The method of any one of claims 1 to 28, wherein the calibration plate includes a plurality of marker blocks thereon, each marker block including at least one marker thereon in the at least one direction, different marker blocks being positioned differently on the calibration plate.
The method of claim 29, wherein said determining the angular resolution of the scanning system in the at least one direction comprises:

determining a mean of a plurality of angular resolutions of the scanning system in a first direction of the at least one direction based on the plurality of marker blocks as the angular resolution of the scanning system in the first direction.
Calibration plate for testing the angular resolution of a scanning system, comprising at least one marker in at least one direction.
The calibration plate of claim 31 wherein the markers are a pair of stripes, the pair of stripes including a first stripe having a first reflectivity and a second stripe having a second reflectivity, and the first reflectivity is greater than the second reflectivity.
The calibration plate of claim 32 wherein the pairs of stripes in a single one of the at least one direction comprise at least two.
A calibration plate according to claim 32 or 33, wherein the width of the pairs of stripes in a single one of said at least one direction comprises at least one.
The calibration plate of claim 34, wherein the width of the pair of stripes in a single direction is from large to small or from small to large.
A calibration plate according to claim 34 or 35, wherein the pairs of stripes of the same width in a single direction comprise one or more.
The calibration plate of any one of claims 34 to 36, wherein the width of at least one fringe pair in a single direction comprises a spot size or scan spacing of the scanning system at a first distance, the first distance being a distance between the scanning system and the calibration plate.
The calibration plate according to any one of claims 32 to 37, wherein the at least one marker belongs to at least one stripe group, each stripe group corresponds to one of the at least one direction, each stripe group comprises at least one stripe element, each stripe element comprises at least one stripe pair, and the width of the stripe pairs in the respective stripe elements in the same stripe group is from large to small or from small to large.
The calibration plate of claim 38 wherein each of said stripe elements comprises three stripe pairs.
A calibration plate according to claim 38 or 39 wherein the pairs of bars in a single bar element are of equal width.
The calibration plate of any one of claims 38 to 40, wherein the width of the pair of stripes is the sum of the width of the first stripe and the width of the second stripe.
The calibration plate according to any one of claims 38 to 41, wherein the width of the first stripe of the pair of stripes is equal to the width of the second stripe, or the width of the first stripe of the pair of stripes is not equal to the width of the second stripe.
Calibration plate according to any one of claims 38 to 41, characterized in that the width of the first stripe in each stripe element within a same stripe group is equal.
Calibration plate according to any one of claims 38 to 43, characterized in that the different sets of bars comprise equal or unequal numbers of bar elements.
A calibration plate according to any one of claims 32 to 44, wherein said pairs of stripes comprise any one of: black and white line pairs, hollow line pairs and color difference line pairs.
Calibration plate according to any of claims 32 to 45, wherein said at least one direction coincides with a scanning direction of the scanning system.
The calibration plate of claim 31, wherein the marker comprises a linear pattern.
Calibration plate according to claim 47, characterized in that the wire types form a rectangular, square or triangular lattice shape.
A calibration plate according to claim 47 or 48, wherein the line pattern comprises any one of: fine lines, paper boards, metal strips, total reflection sheets.
A calibration plate as claimed in any one of claims 31 to 49, wherein the at least one direction comprises: one or more of horizontal direction, vertical direction and inclined direction.
A calibration plate according to claim 50, said oblique direction being a direction at a preset angle to the horizontal, said preset angle being an acute angle.
A calibration plate according to any one of claims 31 to 51, comprising a plurality of marker blocks thereon, each marker block comprising at least one marker in said at least one direction thereon, different marker blocks being positioned differently on the calibration plate.
An apparatus for testing the angular resolution of a scanning system, comprising: a memory and a processor, wherein,

the memory to store computer instructions;

the processor, configured to invoke the computer instructions, and when executed, configured to perform:

acquiring point cloud data after a scanning system scans a calibration plate, wherein the calibration plate comprises at least one marker in at least one direction;

determining an angular resolution of the scanning system in the at least one direction from the point cloud data.
The apparatus of claim 53, wherein the marker is a pair of stripes comprising a first stripe having a first reflectivity and a second stripe having a second reflectivity, and wherein the first reflectivity is greater than the second reflectivity.
The apparatus of claim 54, wherein a stripe pair in a single one of the at least one direction comprises at least two.
The apparatus of claim 54 or 55, wherein the width of the stripe pairs in a single one of the at least one direction comprises at least one.
The apparatus according to claim 56, wherein the width of the stripe pairs in the single direction is from large to small or from small to large.
The apparatus of claim 56 or 57, wherein the pairs of stripes of the same width in the single direction comprise one or more.
The apparatus of any one of claims 56 to 58, wherein the width of at least one fringe pair in the single direction comprises a spot size or scan spacing of the scanning system at a first distance, the first distance being a distance between the scanning system and the calibration plate.
The apparatus according to any one of claims 54 to 59, wherein the at least one marker belongs to at least one stripe group, each stripe group corresponds to one direction of the at least one direction, each stripe group comprises at least one stripe element, each stripe element comprises at least one stripe pair, and the width of the stripe pairs in the stripe elements in the same stripe group is from large to small or from small to large.
The apparatus of claim 60, wherein each stripe element comprises three stripe pairs.
The apparatus of claim 60 or 61, wherein the width of the stripe pairs in a same stripe element is equal.
The apparatus of any one of claims 60 to 62, wherein the width of the pair of stripes is the sum of the width of the first stripe and the width of the second stripe.
The apparatus of any one of claims 60 to 63, wherein the width of the first stripe of the pair of stripes is equal to the width of the second stripe, or wherein the width of the first stripe of the pair of stripes is not equal to the width of the second stripe.
The apparatus of any one of claims 60 to 63, wherein the first stripe in each stripe element within a same stripe group is of equal width.
The apparatus according to any of claims 60 to 65, wherein different groups of stripes comprise equal or unequal numbers of stripe elements.
The apparatus according to any one of claims 54 to 66, wherein the pair of stripes comprises any one of: black and white line pairs, hollow line pairs and color difference line pairs.
The apparatus according to any one of claims 54 to 67, wherein the processor is configured to perform:

determining a minimum width of resolvable second stripes in a first direction of the at least one direction from the point cloud data;

determining an angular resolution of the scanning system in the first direction according to the minimum width of the resolvable second stripe.
The apparatus according to claim 68, wherein the processor is configured to perform:

and determining the minimum width of the resolvable second stripes in the first direction based on the point cloud data according to preset visibility.
The apparatus according to claim 68 or 69, wherein the processor is configured to perform:

determining a ratio of a minimum width of the resolvable second stripe in the first direction to a distance between the scanning system and a location of the minimum width second stripe as an angular resolution of the scanning system in the first direction.
The apparatus of any one of claims 54 to 70, wherein the at least one direction coincides with a scanning direction of the scanning system.
The device of claim 53, wherein the marker comprises a linear form.
The device of claim 72, wherein the wire form forms a rectangular, square, or triangular lattice shape.
The device of claim 72 or 73, wherein the wire form comprises any one of: fine lines, paper boards, metal strips, total reflection sheets.
The apparatus according to any one of claims 72 to 74, wherein the processor is configured to perform:

determining a point cloud width on the line type along a vertical direction of the line type according to the point cloud data;

and determining the angular resolution of the scanning system in the vertical direction of the line type according to the point cloud width.
The apparatus of claim 75, wherein the processor is configured to perform:

calculating the difference between the width of the point cloud and the width of the line type;

determining a ratio of the difference to a distance between the scanning system and a location of the line type as an angular resolution of the scanning system in a vertical direction of the line type.
The apparatus according to any one of claims 72 to 76, wherein the at least one direction is perpendicular to a scanning direction of the scanning system.
The apparatus according to any one of claims 53 to 77, wherein the at least one direction comprises: one or more of horizontal direction, vertical direction and inclined direction.
The device of claim 78, wherein the oblique direction is a direction at a preset angle to the horizontal direction.
The apparatus of any one of claims 53 to 79, wherein the calibration plate is positioned within a field of view of the scanning system, and wherein the processor is further configured to perform:

adjusting a relative positional relationship between the scanning system and the calibration plate by moving the scanning system or moving the calibration plate.
The device of any one of claims 53 to 80, wherein the calibration plate comprises a plurality of marker blocks thereon, each marker block comprising at least one marker in said at least one direction, different marker blocks being positioned differently on the calibration plate.
The apparatus according to claim 81, wherein the processor is configured to perform:

determining a mean of a plurality of angular resolutions of the scanning system in a first direction of the at least one direction based on the plurality of marker blocks as the angular resolution of the scanning system in the first direction.
An angular resolution test system, comprising: an apparatus as claimed in any one of claims 53 to 82 and a calibration plate as claimed in any one of claims 31 to 52.
The angular resolution test system of claim 83, wherein the system further comprises a scanning system.
The angular resolution test system of claim 84, wherein the scanning system comprises a lidar.
A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the method according to any one of claims 1 to 30.