A calibration device and calibration method for improving the testing accuracy of array antennas.

Abstract

This invention relates to a calibration device and method for improving the testing accuracy of array antennas. The device includes: a transmitting plate for mounting the array antenna and a placement plate for fixing the base station antenna. A single-line laser emitter is positioned through the center of the transmitting plate and along a first and second direction on the plane of the transmitting plate. The placement plate is fixedly connected to a first rotating mechanism, which is rotatably connected to a second rotating mechanism. The first and second rotating mechanisms rotate in mutually perpendicular first and second preset directions, respectively. The calibration device adjusts the angle of the placement plate so that the light spot formed by the intersection of the lasers emitted by the two single-line laser emitters on the placement plate is located on its axis. By visually aligning the center positions of the placement plate and the transmitting plate, the device ensures that the quiet zone generated by the array antenna can cover the placement plate, enabling rapid testing of the base station antenna.

Description

Technical Field

[0001] This invention relates to the field of antenna air interface testing technology, and in particular to a calibration device and calibration method for improving the testing accuracy of array antennas. Background Technology

[0002] Before existing base station antennas can be put into use, multiple data tests need to be conducted. This requires setting up an anechoic chamber in the space. Inside the anechoic chamber, a transmitter board for fixing the array antenna is erected on one side. Multiple antennas are arranged in a straight line on the transmitter board. At the same time, a placement board for placing the base station antenna is set up on the side away from the transmitter board. The base station antenna is fixed on the placement board. Then, the transmitting antenna of the array is activated. Through beamforming, a quiet zone is formed at the corresponding position on the placement board. Then, the placement board is controlled to rotate in the vertical and horizontal directions, thereby completing the testing of various data of the base station antenna.

[0003] The aforementioned testing system must ensure that the quiet zone generated by the array antenna covers the placement board. This coverage requires meeting two conditions: firstly, horizontally, the target position of the base station antenna on the placement board must be on the beamforming extension path; secondly, the path of the quiet zone generation must be perpendicular to the plane of the vertically positioned placement board, meaning the plane of the vertically positioned placement board is parallel to the plane of the transmitting board. This ensures that regardless of the distance between the array antenna and the placement board, the quiet zone will not shift upwards or downwards from the placement board's position. However, since electromagnetic waves are invisible and intangible, the relative positions of the placement board and the transmitting board, which are far apart, are not visible to the naked eye. This can easily affect the installation accuracy of the transmitting board in the anechoic chamber, leading to extremely inefficient installation and maintenance of the transmitting board. This problem urgently needs to be solved.

[0004] Therefore, a calibration device is needed to quickly and accurately align the center positions of the placement plate and the transmitter plate, and effectively ensure that the quiet zone generated by the array antenna can cover the placement plate to solve the above-mentioned technical problems. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a calibration device for improving the testing accuracy of array antennas. It solves the problem in existing technologies where the position of the transmitting beam of the transmitting antenna cannot be visually determined to adjust the installation angle of the transmitting board, leading to a deviation between the quiet zone generated by beamforming and the fixed position of the base station antenna, thus affecting the accuracy of base station antenna testing.

[0006] The technical effects of this invention are achieved through the following:

[0007] A calibration device for improving the testing accuracy of array antennas, comprising:

[0008] A transmitting plate for mounting an array antenna is provided with a line laser emitter in both a first direction and a second direction passing through the center of the transmitting plate, and the first direction and the second direction are both located on the plane of the transmitting plate;

[0009] A mounting plate for fixing a base station antenna is fixedly connected to a first rotating mechanism, which is rotatably connected to a second rotating mechanism. The first rotating mechanism rotates in a first preset direction, and the second rotating mechanism is rotatably connected to a base. The second rotating mechanism rotates in a second preset direction, and the first preset direction is perpendicular to the second preset direction. The calibration device changes the angle of the mounting plate by adjusting the first and second rotating mechanisms so that the light spot formed by the intersection point of the lasers emitted by the two line laser emitters on the mounting plate is located on the axis of the mounting plate.

[0010] Furthermore, a fixed base is rotatably connected to the center of the transmitter plate, and the transmitter plate rotates around its axis in the plane where the transmitter plate is located. The plane where the direction of rotation of the transmitter plate is located is perpendicular to the plane where the second preset direction is located. The transmitter plate is used to observe whether the light spot formed during its rotation is within the threshold range to determine the calibration degree of the array antenna.

[0011] Furthermore, the threshold range is defined as a threshold region formed by drawing a circle with the target point as the center and a preset length as the radius, using the light spot formed when the emitting plate is in its initial state as the target point. By setting a threshold range on the placement plate, the alignment of the placement plate and the emitting plate can be determined by observing whether the light spot formed on the placement plate at the laser intersection point is within the threshold range during the rotation of the emitting plate. This transforms the beam alignment, which is difficult to judge visually, into a relative positional relationship between the laser-formed light spot and the threshold range, thus achieving the function of quickly aligning the placement plate and the emitting plate using a visualization method.

[0012] Furthermore, the first direction and the second direction are perpendicular. The emitting plate is configured to use a level to adjust the mounting angle of the emitting plate on the fixed base using lasers emitted from the linear laser emitter in the first and second directions, so that the plane on which the emitting plate is located is in a vertical state. By setting two linear laser emitters to emit lasers in the mutually perpendicular first and second directions respectively to obtain cross-shaped calibration lasers on the plane on which the emitting plate is located, the verticality calibration of the emitting plate can be completed using a level. This ensures that the static area and the placement plate will not be misaligned or parallel after the placement plate and the emitting plate are aligned subsequently, effectively simplifying the alignment steps of the emitting plate and the placement plate.

[0013] Furthermore, a first guide rail is slidably connected to the lower part of the base. The first guide rail is located in the horizontal direction and its extension direction is parallel to the plane where the launch plate is located.

[0014] Furthermore, the base slides on the first guide rail so that the light spot formed by the emitting plate in the initial state is located at the center of the placement plate.

[0015] Furthermore, a second guide rail is provided below the first guide rail, and the extension direction of the second guide rail is perpendicular to the extension direction of the first guide rail. The first guide rail slides on the second guide rail to make the antenna base station fixed on the placement plate fall into the quiet zone formed by the transmitting antenna beam on the transmitting plate.

[0016] In addition, a calibration method for improving the testing accuracy of array antennas is also provided. This method is based on the aforementioned calibration device for improving the testing accuracy of array antennas and includes:

[0017] Adjust the mounting position of the transmitter plate to ensure it is vertical;

[0018] The first rotating mechanism is controlled to rotate in a first preset direction so that the placement plate is in a vertical state;

[0019] The second rotating mechanism is controlled to rotate in the second preset direction so that the light spot formed on the placement plate at the intersection of the lasers emitted by the two line laser emitters is located on its axis.

[0020] Draw a circle with the location of the light spot as the center and the preset length as the radius to obtain the threshold range on the placement plate;

[0021] The emission plate is controlled to rotate around its axis in its plane to ensure that all light spots formed in real time during the rotation of the emission plate are within the threshold range.

[0022] Furthermore, adjust the mounting position of the transmitter plate to ensure it is in a vertical position, including:

[0023] Control two linear laser emitters to emit lasers to obtain a first calibration laser and a second calibration laser that intersect perpendicularly;

[0024] Place the level on the first calibration laser to adjust the level of the line laser emitter located in the first direction;

[0025] After controlling the emitter plate to rotate 90 degrees, place the level on the second calibration laser to adjust the level of the line laser emitter located in the second direction, so as to adjust the emitter plate to a vertical state.

[0026] Furthermore, controlling the second rotating mechanism to rotate around the base so that the light spot formed on the placement plate at the intersection of the lasers emitted by the two linear laser emitters is located on its axis includes:

[0027] The control base slides on the first guide rail so that the light spot formed by the emission plate in the initial state is located at the center of the placement plate.

[0028] As described above, the present invention has the following beneficial effects:

[0029] 1) By setting a threshold range on the placement plate, the alignment of the placement plate and the emission plate can be determined by observing whether the light spot formed by the laser intersection point on the placement plate is within the threshold range during the rotation of the emission plate. This transforms the beam alignment, which is difficult to judge by the naked eye, into the relative positional relationship between the laser-formed light spot and the threshold range. The visualization method enables the rapid alignment of the placement plate and the emission plate.

[0030] 2) By setting two linear laser emitters to emit lasers in the first and second directions, which are perpendicular to each other, a cross-shaped calibration laser is obtained on the plane where the emitter plate is located. This allows the verticality of the emitter plate to be calibrated using a level, ensuring that the static area and the place plate will not be misaligned or parallel after the place plate and the emitter plate are aligned. This effectively simplifies the alignment steps of the emitter plate and the place plate. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the present invention, the accompanying drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0032] Figure 1 A schematic diagram of a calibration device for improving the testing accuracy of an array antenna, provided as an embodiment of this specification;

[0033] Figure 2 This is a flowchart of a calibration device for improving the testing accuracy of an array antenna, provided as an embodiment of this specification.

[0034] The corresponding reference numerals in the figure are:

[0035] Launching plate 1, placement plate 2, first rotating mechanism 3, first base 31, U-shaped turntable 32, second rotating mechanism 4, base 5, fixed seat 6, first guide rail 7, second guide rail 8. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0038] Example 1:

[0039] like Figure 1 and Figure 2 As shown in the embodiments of this specification, a calibration device for improving the testing accuracy of array antennas is provided. The calibration device is located in an anechoic chamber and includes:

[0040] The transmitter plate 1 used to mount the array antenna has a line laser transmitter in both the first and second directions passing through the center of the transmitter plate 1. The first and second directions are both located on the plane of the transmitter plate 1.

[0041] A mounting plate 2 for fixing a base station antenna is included. The mounting plate 2 is fixedly connected to a first rotating mechanism 3, which is rotatably connected to a second rotating mechanism 4. The first rotating mechanism 3 rotates in a first preset direction, while the second rotating mechanism 4 is rotatably connected to a base 5 and rotates in a second preset direction. The first and second preset directions are perpendicular. The calibration device adjusts the angle of the mounting plate 2 by adjusting the first rotating mechanism 3 and the second rotating mechanism 4, so that the light spot formed on the mounting plate 2 at the intersection of the lasers emitted by the two linear laser emitters is located on the axis of the mounting plate 2. A fixing mechanism is provided on the mounting plate 2 to fix the base station antenna under test onto the mounting plate 2.

[0042] In this embodiment, the second preset direction is located in the horizontal direction, and the first preset direction is located in the vertical direction. When the placement plate 2 is parallel to the launching plate 1, the plane containing the first preset direction is perpendicular to the plane containing the launching plate 1.

[0043] It should be noted that, in order to ensure that the array antenna in the anechoic chamber can be accurately aligned with the target position of the placement plate 2 before operation, so that after the base station antenna is fixed on the placement plate 2, the array antenna is activated to form a beamforming quiet zone covering the location of the placement plate 2. Then, the base station antenna is rotated in multiple directions within the quiet zone by the rotation of the first rotation mechanism 3 and the second rotation mechanism 4, thereby playing the role of comprehensively detecting various data of the base station antenna.

[0044] Specifically, the first rotating mechanism 3 includes a first base 31 and a U-shaped turntable 32. The bottom of the U-shaped turntable 32 is rotatably connected to the first base 31. The U-shaped turntable 32 rotates around the axial direction of the first base 31. The U-shaped turntable 32 has a symmetrical structure, and its two ends are fixedly connected to the two ends of the placement plate 2. The axial direction of the first base 31 is in the horizontal direction.

[0045] Specifically, the second rotating mechanism 4 is a rotating platform located in the horizontal direction. The rotating platform and the base 5 are rotatably connected. The axial direction of the rotating platform and the axial direction of the base 5 are on the same straight line. The rotating platform is used to rotate around its axial direction. The first base 31 is fixedly connected to the rotating platform.

[0046] The axis of the rotating platform passes through the center point of the first base 31. When the U-shaped turntable 32 is in a vertical state, the axis of the rotating platform 32 is the axis of the U-shaped turntable.

[0047] Since the placement plate 2 cannot be guaranteed to be in a completely vertical state after it is installed on the first rotating mechanism 3, and may be slightly tilted, the first rotating mechanism 3 is set up so that the placement plate 2 can be adjusted to a vertical state by rotating the U-shaped turntable 32.

[0048] A second rotating mechanism 4 is provided so that by rotating the rotating table, the plane where the placement plate 2 is located can be made parallel to the plane where the launch plate 1 is located.

[0049] In this embodiment, a first guide rail 7 is slidably connected to the lower part of the base 5. The first guide rail 7 is located in the horizontal direction and its extension direction is parallel to the plane where the launch plate 1 is located.

[0050] The light spot formed by the emitting plate 1 in its initial state can be positioned at the center of the placement plate 2 by sliding the base 5 on the first guide rail 7, that is, the center of the placement plate 2 is selected as the target point. In the initial state, both the emitting plate 1 and the placement plate 1 are adjusted to a vertical position.

[0051] Specifically, a level is placed on both the transmitting plate 1 and the placement plate 2 to ensure that both are perpendicular to the ground. Then, the linear laser transmitter is activated. By adjusting the vertical position of the transmitting plate 1 and adjusting the horizontal angle of the placement plate 2 via the second rotating mechanism 4, the laser beams at the intersection of the calibration beams illuminate the target point, thus completing the basic calibration steps for the array antenna in the anechoic chamber. The level used to ensure the vertical position of the transmitting plate 1 and the placement plate 2 can be a frame-type level.

[0052] By using the horizontally positioned bottom wall of the anechoic chamber as a reference, both the placement plate 2 and the transmitting plate 1 are perpendicular to the ground, and their centers are at the same height. This ensures that the quiet zone generated by the array antenna on the transmitting plate 1 will not be misaligned or parallel to the space perpendicular to the placement plate 2 after the placement plate 2 and the transmitting plate 1 are aligned. Compared to direct alignment, aligning the transmitting plate 2 and the placement plate 1 perpendicular to the ground first reduces the degrees of freedom that need to be considered when aligning the placement plate 2 and the transmitting plate 1, simplifying the alignment process and making it easier for operators to work with the placement plate 2 and the transmitting plate 1.

[0053] Preferably, a fixed base 6 is rotatably connected to the center position of the emitting plate 1, and the emitting plate 1 rotates around its axis in the plane where the emitting plate 1 is located. The plane where the rotation direction of the emitting plate 1 is located is perpendicular to the plane where the second preset direction is located. The emitting plate 1 is used to observe whether all the light spots formed during the rotation are within the threshold range by human observation.

[0054] Specifically, when the launching plate 1 and the placement plate 2 are parallel, the first rotating mechanism 3 drives the plane of the rotation direction of the placement plate 2 to be perpendicular to the plane of the launching plate 1, that is, perpendicular to the plane of the rotation direction of the launching plate 1.

[0055] The threshold range is defined as follows: the light spot formed by the emitting plate 1 in its initial state at the center of the placement plate 2 is taken as the target point, and a threshold area is formed by drawing a circle with the target point as the center and a preset length as the radius. The threshold area is marked on the placement plate 2 for easy observation. The preset length can be set by those skilled in the art.

[0056] Specifically, during the 360-degree rotation of the transmitter plate 1, observe whether the movement area of ​​the light spot projected by the intersection of the calibration laser on the placement plate 2 remains within the threshold range. If the light spot formed on the placement plate 2 exceeds the threshold range during the rotation of the transmitter plate 1, the operator needs to adjust the installation angle of the transmitter plate 1 relative to the fixed base 6 according to the angle direction of the light spot generated by the calibration laser on the placement plate 2 relative to the target point; if the light spot of the calibration laser on the placement plate 2 remains within the threshold range during the rotation of the transmitter plate 1, the verification and calibration process of the array antenna is completed, and the relative position adjustment of the transmitter plate 1 and the placement plate 2 is stopped.

[0057] By marking the threshold range on the placement plate 2 and then rotating the transmitting plate 1, the relative positional relationship between the laser intersection point forming a light spot on the placement plate 2 and the threshold range is observed. This allows for the determination of the alignment between the placement plate 2 and the transmitting plate 1, thus transforming the difficult-to-determine alignment into the positional relationship between a visible light spot and a visible, bounded threshold range. This achieves visibility and standardization in the process of adjusting the alignment between the placement plate 2 and the transmitting plate 1, enabling a rapid and accurate calibration process for the array antenna, which facilitates the rapid testing of subsequent base station antennas.

[0058] After verification and calibration are completed, the position of the transmitter plate 1 is finally fixed in the corresponding position of the mounting base 6 by mechanical structure, and then the line laser transmitter on the transmitter plate 1 is removed.

[0059] Preferably, a second guide rail 8 is provided below the first guide rail 7. The extension direction of the second guide rail 8 is perpendicular to the extension direction of the first guide rail 7. The first guide rail 7 slides on the second guide rail 8 so that the antenna base station fixed on the placement plate 2 falls into the quiet zone formed by the transmitting antenna beam on the transmitting plate 1.

[0060] like Figure 2 As shown in the embodiments of this specification, a calibration method for improving the testing accuracy of an array antenna is provided. This method is based on the calibration device for improving the testing accuracy of an array antenna in Embodiment 1, and includes:

[0061] S100: Adjust the installation position of the transmitter plate 1 so that it is in a vertical position;

[0062] S200: Control the first rotating mechanism 3 to rotate in a first preset direction so that the placement plate 2 is in a vertical state;

[0063] S300: Control the second rotating mechanism 4 to rotate in the second preset direction so that the light spot formed on the placement plate 2 at the intersection of the lasers emitted by the two line laser emitters is located on its axis.

[0064] S400: Draw a circle with the location of the light spot as the center and the preset length as the radius to obtain the threshold range on the placement plate 2;

[0065] S500: Control the emission plate 1 to rotate around its axis in its plane to ensure that all light spots formed in real time during the rotation of the emission plate 1 are within the threshold range.

[0066] In one specific embodiment, step S100, adjusting the mounting position of the transmitter plate 1 to make it vertical, includes:

[0067] Control two linear laser emitters to emit lasers to obtain a first calibration laser and a second calibration laser that intersect perpendicularly;

[0068] Place the level on the first calibration laser to adjust the level of the line laser emitter located in the first direction;

[0069] After controlling the emitter plate 1 to rotate 90 degrees, place the level on the second calibration laser to adjust the level of the line laser emitter located in the second direction, so as to adjust the emitter plate 1 to a vertical state.

[0070] In one specific embodiment, step S300 controls the second rotating mechanism 4 to rotate around the base 5 so that the light spot formed on the placement plate 2 at the intersection of the lasers emitted by the two line laser emitters is located on its axis, including:

[0071] The control base 5 slides on the first guide rail 7 so that the light spot formed by the emitting plate 1 in the initial state is located at the center of the placement plate 2.

[0072] While the present invention has been described through preferred embodiments, it is not limited to the embodiments described herein, and various changes and modifications are made without departing from the scope of the invention.

[0073] In this document, the directional terms such as front, back, top, and bottom are defined based on the location of the components in the accompanying drawings and their relative positions to each other, solely for the purpose of clarity and convenience in expressing the technical solution. It should be understood that the use of these directional terms should not limit the scope of protection claimed in this application.

[0074] Where there is no conflict, the above embodiments and features described herein can be combined with each other.

[0075] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A calibration device for improving the test accuracy of a phased array antenna, characterized in that, The utility model relates to a kind of calibration device of array antenna, including: The first direction and the second direction of the center of the emission plate (1) for installing array antenna are provided with a linear laser emitter, the first direction and the second direction are located on the plane where the emission plate (1) is located, and the first direction and the second direction are perpendicular; The placement plate (2) for fixing base station antenna is fixedly connected with the first rotating mechanism (3), the first rotating mechanism (3) is rotatably connected with the second rotating mechanism (4), the first rotating mechanism (3) rotates in the first preset direction, the second rotating mechanism (4) is rotatably connected with the base (5), the second rotating mechanism (4) rotates in the second preset direction, the first preset direction is perpendicular to the second preset direction, and the calibration device changes the angle of the placement plate (2) by adjusting the first rotating mechanism (3) and the second rotating mechanism (4), so that the intersection point of the laser emitted by the two linear laser emitters forms a light spot on the placement plate (2) on the axis of the placement plate (2); The center position of the emission plate (1) is rotatably connected with the fixed seat (6), and the emission plate (1) rotates around its axial direction in the plane where the emission plate (1) is located, the plane where the rotating direction of the emission plate (1) is located is perpendicular to the plane where the second preset direction is located, and the emission plate (1) is used to judge the calibration degree of array antenna by observing whether the light spot formed in the rotating process is located within the threshold range.

2. The calibration device for improving the test precision of a phased array antenna according to claim 1, characterized in that, The threshold range is a threshold area formed by taking the light spot formed when the emission plate (1) is in the initial state as a target point and making a circle with the target point as the center and a preset length as the radius.

3. The calibration device for improving the test precision of a phased array antenna according to claim 2, characterized in that, The emission plate (1) is arranged to adjust the installation angle of the emission plate (1) on the fixed seat (6) by the laser of the first direction and the second direction emitted by the linear laser emitter using the level, so that the plane where the emission plate (1) is located is in the vertical state.

4. The calibration device for improving the test precision of a phased array antenna according to claim 3, characterized in that, The lower side of the base (5) is slidably connected with the first guide rail (7), the first guide rail (7) is located in the horizontal direction, and the extension direction of the first guide rail (7) is parallel to the plane where the emission plate (1) is located.

5. The calibration device for improving the test precision of a phased array antenna according to claim 4, characterized in that, The base (5) slides on the first guide rail (7) so that the light spot formed by the emission plate (1) in the initial state is located at the center of the placement plate (2).

6. The calibration device for improving the test precision of a phased array antenna according to claim 5, characterized in that, The lower side of the first guide rail (7) is provided with the second guide rail (8), the extension direction of the second guide rail (8) is perpendicular to the extension direction of the first guide rail (7), and the first guide rail (7) falls into the quiet zone formed by the emission beam of the emission antenna on the emission plate (1) by sliding on the second guide rail (8).

7. A calibration method for improving the test accuracy of an array antenna, which is implemented based on the calibration device for improving the test accuracy of an array antenna according to any one of claims 1-6, characterized in that, Including: Adjust the installation position of the emission plate (1) so that it is in the vertical state; Control the first rotating mechanism (3) to rotate in the first preset direction so that the placement plate (2) is in the vertical state; Controlling the second rotating mechanism (4) to rotate in the second preset direction, so that the intersection of the laser beams emitted by the two linear laser emitters is located on the axis of the light spot formed on the placement plate (2); Making a circle with the position of the light spot as the center and a preset length as the radius to obtain a threshold range on the placement plate (2); Controlling the emission plate (1) to rotate around its axis in the plane where it is located to ensure that all the light spots formed in real time during the rotation of the emission plate (1) are located within the threshold range.

8. The calibration method for improving the test precision of a phased array antenna according to claim 7, wherein the first direction and the second direction are perpendicular. Adjusting the installation position of the emission plate (1) to make it in a vertical state, including: controlling the two linear laser emitters to emit laser beams to obtain first and second calibration lasers that are perpendicular to each other; Placing the level on the first calibration laser to adjust the levelness of the linear laser emitter located in the first direction; After controlling the emission plate (1) to rotate by 90 degrees, placing the level on the second calibration laser to adjust the levelness of the linear laser emitter located in the second direction, so as to adjust the emission plate (1) to a vertical state.

9. The calibration method for improving the test accuracy of a phased array antenna according to claim 8, a first guide rail (7) is slidably connected below the base (5), the first guide rail (7) is located in the horizontal direction and the extension direction of the first guide rail (7) is parallel to the plane where the launch panel (1) is located, characterized in that, Controlling the second rotating mechanism (4) to rotate around the base (5) so that the intersection of the laser beams emitted by the two linear laser emitters is located on the axis of the light spot formed on the placement plate (2), including: controlling the base (5) to slide on the first guide rail (7) to make the light spot formed by the emission plate (1) in the initial state located on the center position of the placement plate (2).

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