Reflector antenna field calibration device and calibration method

Abstract

The invention provides a reflector antenna field calibration device, and the device comprises a support assembly which is used for positioning and fixing a reflector antenna, and carrying out the testing and field calibration through a photogrammetry system, and is provided with a plurality of target points; the supporting assembly is used for supporting the bracket assembly and adjusting the height and the angle of the bracket assembly; wherein the supporting assembly is composed of a bottom plate, a supporting fixture and an adjusting module, the adjusting module is connected with the supporting fixture in a threaded connection mode and used for adjusting the height and the angle of the supporting assembly in the vertical direction, and the bottom plate is used for being connected with the support assembly; the support assembly is composed of a support bottom plate, a rotating shaft, a support fixture and an antenna installation bottom plate. The support bottom plate is connected with the support fixture and the supporting assembly, the rotating shaft is connected with the support bottom plate and used for being positioned with the supporting assembly and driving the support assembly to rotate so as to adjust the azimuth angle, and the antenna mounting bottom plate is connected with the support fixture and used for mounting and positioning a reflector antenna.

Description

Technical Field

[0001] The invention relates to a reflector antenna site calibration device and a calibration method. Background Art

[0002] Before conducting radiation performance tests on satellite-borne reflector antennas, it is necessary to adjust the beam pointing of the reflector to be parallel to the incoming wave direction of the test site. The accuracy of site calibration has a great impact on the electrical performance indicators of the antenna product. Figure 1 As shown, the antenna is generally installed on a three-dimensional test turntable, a station is established through the theodolite system, the reference hole and probe of the reflecting surface are measured, the conversion relationship between the site coordinate system and the antenna coordinate system is established, and the outgoing wave direction of the reflecting surface is adjusted to be consistent with the incoming wave direction of the test field by rotating the test turntable.

[0003] Traditional satellite-borne antennas are generally produced in single pieces or in small quantities, and there is basically no mass production testing. The existing field calibration methods for reflector antennas have the following main shortcomings:

[0004] 1. When the satellite-borne reflector antenna is calibrated on site, the calibration process varies greatly between different antennas. A test turntable is required for installation and debugging to achieve antenna calibration. A dedicated test turntable usually costs millions and is expensive. In addition, the test turntable has a complex structure and occupies a large space, which further increases the requirements for test site space.

[0005] 2. When using the theodolite for testing, the theodolite bracket, theodolite head, TP-LINK, test computer and other test equipment and tools must be transported to the test site before the theodolite system is connected to the site. Site calibration usually takes one day, and the test efficiency is low.

[0006] 3. The satellite-borne antenna is a near-field test. The distance between the reflector and the antenna probe is small. The traditional method of setting up four theodolites between the probe and the reflector antenna is used. Due to obstruction, the probe and the reflector antenna cannot be tested at the same time. Summary of the invention

[0007] In order to solve the above problems of the traditional site calibration method, the present application provides a reflector antenna site calibration device, comprising:

[0008] A bracket assembly, used for positioning and fixing the reflector antenna, and for testing and field calibration using a photogrammetry system, with multiple target points on the bracket assembly;

[0009] A support assembly, used to support the bracket assembly and adjust the height and angle of the bracket assembly;

[0010] The support assembly is composed of a base plate, a support frame and an adjustment module. The adjustment module is connected to the support frame in a screw connection form and is used for adjusting the height and angle of the support assembly in the up and down directions. The base plate is used to connect with the bracket assembly.

[0011] Among them, the bracket assembly is composed of a bracket base plate, a rotating shaft, a bracket frame, and an antenna mounting base plate; the bracket base plate is connected to the bracket frame and the support assembly, the rotating shaft is connected to the bracket base plate, and is used to position with the support assembly and drive the bracket assembly to rotate to adjust the azimuth angle; the antenna mounting base plate is connected to the bracket frame and is used for installation and positioning of the reflector antenna.

[0012] In at least one embodiment, the reflector antenna to be measured is positioned on the bracket assembly with pins and then installed and fixed with screws.

[0013] In at least one embodiment, there are four target points on the stent assembly 2 .

[0014] In at least one embodiment, a measuring camera is further included, which is used to obtain the three-dimensional coordinates of the target point.

[0015] In at least one embodiment, the measurement camera is located on a side of the support assembly opposite to the probe.

[0016] The present application also provides a reflector antenna site calibration method, wherein the above device performs reflector antenna site calibration, and the method comprises:

[0017] S1: Install the reflector antenna on the bracket assembly and stick multiple target points on the front of the reflector antenna;

[0018] S2: Take photos of the reflector antenna and the bracket assembly through the measuring camera of the photogrammetry system, measure the target points on the reflector antenna and the bracket assembly using the photogrammetry system, and calculate the coordinate value of the target point of the bracket assembly in the antenna coordinate system through common point conversion based on the coordinate value of the target point of the reflector antenna in the antenna coordinate system;

[0019] S3: Target points are pasted on the site ground and the site probe. The target points on the probe can be switched between multiple positions as the site probe moves. The target points of the probe, the targets of the bracket assembly, and the site target points are photographed and tested by the camera of the photogrammetry system to obtain the coordinate conversion relationship between the probe target points and the site target points. The site coordinate system is established by the coordinates of the probe target points, and the coordinate values ​​of the site target points are obtained in the site coordinate system.

[0020] S4: Take photos at multiple photogrammetry shooting points respectively, use the photogrammetry system to measure and obtain the conversion relationship between the bracket component target point and the site target point, and obtain the conversion relationship Rx, Ry, Rz between the antenna coordinate system and the site coordinate system through the coordinates of the bracket component target point in the site coordinate system;

[0021] S5: According to the conversion relationship Rx, Ry, Rz between the antenna coordinate system and the ground coordinate system, adjust the bracket assembly and the adjustment module of the support assembly. After adjustment, use the photogrammetry system to measure the conversion relationship between the bracket assembly target point and the site target point, so that Rx, Ry, Rz are less than a certain threshold, meet the site calibration requirements of the antenna, and complete the first antenna site calibration.

[0022] In at least one embodiment, the method further comprises:

[0023] S6: After completing the first antenna site calibration, perform the batch test site calibration step, keep the positions of the support assembly and the bracket assembly unchanged, install the reflector antenna to the bracket assembly with the positioning pins according to step S1, paste multiple target points on the front of the reflector antenna, and then directly calibrate the bracket assembly target point with the site target point to complete the site calibration.

[0024] In at least one embodiment, the system software is used to automatically process, identify, and match the images obtained by the measuring camera, and after bundle adjustment, the three-dimensional coordinates of the target point are obtained.

[0025] In at least one embodiment, wherein

[0026] There are 4 target points attached to the front of the reflector antenna;

[0027] The target point on the probe can be switched between 4 positions as the field probe moves;

[0028] There are 4 field target points on the field ground.

[0029] In at least one embodiment, Rx, Ry, and Rz are set to ≤ 0.03°.

[0030] The special test tooling for antenna installation and debugging provided in this application can replace the turntable for antenna installation, erection and debugging, and the cost is reduced from several million to tens of thousands, which can greatly reduce the cost;

[0031] The photogrammetry-based site calibration method provided in the present application converts the measurement references of the reflector antenna and the test probe, and can use photogrammetry to take pictures to achieve test calibration, thereby solving the technical problem that the satellite-borne reflector antenna of the present invention cannot be directly tested for site calibration.

[0032] The field calibration method provided in this application completes the field calibration verification of the first product, and based on the field calibration result of the first antenna product, uses tooling for positioning to ensure antenna installation accuracy for batch production, simplifies the test process, and reduces the field calibration time from half a day for the first product to 1 hour, thereby improving the efficiency of field calibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The following will further explain the above characteristics, technical features, advantages and implementation methods of the present application in a clear and understandable manner through the description of the preferred embodiments and in combination with the accompanying drawings. The following drawings are only intended to illustrate and explain the present application, and do not limit the scope of the present application. Among them:

[0034] Figure 1 This is a schematic diagram of the site calibration of an existing space-borne reflector antenna;

[0035] Figure 2 The reflector antenna site calibration device of the present application is shown;

[0036] Figure 3 The support assembly of the present application is shown;

[0037] Figure 4 The bracket assembly of the present application is shown;

[0038] Figure 5 The reflector antenna and the target point on the bracket assembly are shown;

[0039] Figure 6 A schematic diagram showing the conversion of the probe target point to the ground target point is shown;

[0040] Figure 7 It is a schematic diagram of the calibration between the bracket target point and the field target point;

[0041] Figure 8 It is a schematic diagram of adjusting the bracket assembly;

[0042] Fig. 9 Schematic diagram of support component adjustment. DETAILED DESCRIPTION

[0043] In order to have a clearer understanding of the technical features, purposes and effects of the present application, the specific implementation methods of the present application are now described with reference to the accompanying drawings.

[0044] The present application provides a reflector antenna site calibration device, which does not require an expensive test turntable and can reduce costs;

[0045] The present application also provides a method for site calibration of a reflector antenna based on photogrammetry, which can solve the technical problems of site calibration in the prior art;

[0046] The present application also provides a method for rapid field calibration suitable for batch production, which can improve the efficiency of field calibration.

[0047] like Figure 2 As shown, a reflector antenna site calibration device provided by an embodiment of the present application includes:

[0048] Bracket assembly 2 is used to position and fix the reflector antenna and to carry out testing and site calibration using the photogrammetry system. The reflector antenna to be tested is positioned on bracket assembly 2 with pins and then installed and fixed with screws. Figure 5 As shown, the stent assembly 2 has a plurality of target points ZH1, ZH2, ZH3, and ZH4;

[0049] Support assembly 1, used to support support assembly 2 and adjust the height and angle of support assembly 2;

[0050] Among them, Figure 3 As shown, the support assembly 1 is composed of a base plate 1-1, a support frame 1-2 and an adjustment module 1-3. The support frame 1-2 is welded from aluminum square tubes. After welding, the upper and lower surfaces are finely processed using CNC machine tools to ensure the basic structural dimensions of the tooling while having sufficient strength and rigidity. The adjustment module 1-3 is connected to the support frame 1-2 by screwing, and is used to adjust the height and angle adjustment of the support assembly 1 in the upper and lower directions. The base plate 1-1 is an aluminum alloy plate, and the surface is finely processed to ensure accuracy. It is connected and fixed to the support frame 1-2 by screwing. The base plate 1-1 is used to connect to the bracket assembly 2.

[0051] Among them, Figure 4 As shown, the bracket assembly 2 is composed of a bracket base plate 2-1, a rotating shaft 2-2, a bracket frame 2-3, and an antenna mounting base plate 2-4. The bracket frame 2-3 is welded from aluminum square tubes. After welding, the left support surface and the lower surface are finely processed using CNC machine tools to ensure the basic structural dimensions of the tooling while having sufficient strength and rigidity. The bracket base plate 2-1 is made of aluminum alloy plate, on which pins and screw holes are processed, and is connected to the bracket frame 2-3 and the support assembly 1 by screwing. The rotating shaft 2-2 is screwed to the bracket base plate 2-1, which is used to position the support assembly 1 and drive the bracket assembly 2 to rotate and adjust the azimuth angle. The antenna mounting base plate 2-4 is screwed to the bracket frame 2-3, which is used for the installation, positioning and fixation of the reflector antenna.

[0052] The present application also provides a reflector antenna site calibration method using a photogrammetry system, which uses an industrial measurement camera to capture images, and uses system software to automatically process, identify, and match the images. After bundle adjustment, the three-dimensional coordinates of the target point can be obtained.

[0053] In the reflector antenna site calibration method using a photogrammetry system provided in the present application, the reflector antenna site calibration process is divided into the first calibration and batch calibration. The purpose of the first calibration is to obtain the coordinate conversion relationship between the site coordinate system established by the antenna test field probe and the reflector antenna coordinate system. After the first calibration is completed, in the site coordinate system, the reflector antenna coordinate system rotation angles Rx, Ry, Rz ≤ 0.03°. After the first calibration is completed, the bracket assembly 2 and the support assembly 1 are fixed. When the site batch calibration is carried out subsequently, the reflector antenna to be tested is installed on the bracket assembly 2, and the target point of the bracket assembly 2 and the site target point are used to carry out the site calibration.

[0054] A reflector antenna site calibration method provided by an embodiment of the present application includes the following steps:

[0055] S1: Figure 2 As shown, the reflector antenna is mounted on the bracket assembly 2 with a positioning pin, four target points BBD1, BBD2, BBD3, and BBD4 are pasted on the front of the reflector antenna, and target points ZH1, ZH2, ZH3, and ZH4 are pasted on the bracket assembly 2. Figure 5 As shown;

[0056] S2: Take a photo test of the reflector antenna and the bracket assembly 2 through the camera of the photogrammetry system, measure the target points BBD1, BBD2, BBD3, BBD4 on the reflector antenna, and the target points ZH1, ZH2, ZH3, ZH4 on the bracket assembly 2 by using the photogrammetry system, and based on the coordinate values ​​of the reflector antenna target points BBD1, BBD2, BBD3, BBD4 in the antenna coordinate system, calculate the coordinate values ​​of the four target points ZH1, ZH2, ZH3, ZH4 of the bracket assembly 2 in the antenna coordinate system through common point conversion;

[0057] S3: Press Figure 6 As shown, the site coordinate system is a site coordinate system composed of a plane formed by the movement of the site and a normal line perpendicular to the plane. The target point is pasted on the site probe, and the site probe can be switched between four positions, so that the target point on the probe can be switched between four positions TT1, TT2, TT3, and TT4. The camera of the photogrammetry system is used to take pictures of the target point positions TT1, TT2, TT3, and TT4 of the probe, the four target points ZH1, ZH2, ZH3, and ZH4 of the bracket assembly 2, and the site target points CD1, CD2, CD3, and CD4 to obtain the coordinate conversion relationship between the four probe target points TT1, TT2, TT3, and TT4 and the four ground target points CD1, CD2, CD3, and CD4. The site coordinate system is established through the coordinates of the four probe target points TT1, TT2, TT3, and TT4, and the coordinate values ​​of the site target points CD1, CD2, CD3, and CD4 are obtained in the site coordinate system.

[0058] S4: Figure 7 As shown, photos are taken at three positions, namely, photogrammetry shooting point 1, photogrammetry shooting point 2 and photogrammetry shooting point 3, respectively. The photogrammetry system is used to measure the conversion relationship between the target points ZH1, ZH2, ZH3, ZH4 of the bracket assembly 2 and the site target points CD1, CD2, CD3, CD4. In the site coordinate system established by the site target points CD1, CD2, CD3, CD4, the conversion relationships Rx, Ry, Rz between the antenna coordinate system and the site coordinate system are obtained through the coordinates of the bracket assembly target points ZH1, ZH2, ZH3, ZH4.

[0059] S5: Figure 8 and Fig. 9 As shown, according to the conversion relationship Rx, Ry, Rz between the antenna coordinate system and the site coordinate system, Rz is changed by adjusting the bracket assembly 2, and Rx and Ry are changed by adjusting the adjustment modules 1-3 of the support assembly 1. After adjustment, the conversion relationship between the target points ZH1, ZH2, ZH3, ZH4 of the bracket assembly 2 and the site target points CD1, CD2, CD3, CD4 is measured using a photogrammetry system, so that Rx, Ry, Rz ≤ 0.03°, meeting the site calibration requirements of the antenna, and completing the first antenna site calibration.

[0060] S6: After completing the first antenna field calibration, perform the batch test field calibration step, keep the positions of support component 1 and bracket component 2 unchanged, install the reflector antenna to the bracket component 2 with the positioning pin according to step S1, and paste 4 target points BBD1, BBD2, BBD3, and BBD4 on the front of the reflector antenna. Then, directly calibrate the target point of bracket component 2 with the field target point to complete the field calibration.

[0061] In summary, the reflector antenna site calibration method provided in this application includes the following steps:

[0062] S1: When the antenna is first calibrated on site, install the antenna to be tested on the bracket assembly;

[0063] S2: Convert the antenna target point to the target point of bracket assembly 2;

[0064] S3: convert the probe target point to the field target point;

[0065] S4: Obtain the conversion relationship Rx, Ry, Rz between the antenna coordinate system and the site coordinate system;

[0066] S5: calibrate the target point of bracket assembly 2 and the target point of the site in sequence to complete the first-piece site calibration of the antenna;

[0067] S6: Start batch test site calibration, install the antenna to be tested on the bracket assembly 2, and directly calibrate the target point of the bracket assembly 2 with the site target point.

[0068] The above description is only an illustrative embodiment of the present application and is not intended to limit the scope of the present application. Any equivalent changes, modifications and combinations made by any technician in the field without departing from the concept and principle of the present application shall fall within the scope of protection of the present application.

Claims

1. A reflector antenna site calibration device, comprising: A bracket assembly, used for positioning and fixing the reflector antenna, and for testing and field calibration using a photogrammetry system, with multiple target points on the bracket assembly; A support assembly, used for supporting the bracket assembly and adjusting the height and angle of the bracket assembly; The support assembly is composed of a base plate, a support frame and an adjustment module. The adjustment module is connected to the support frame in a screw connection form and is used for adjusting the height and angle of the support assembly in the up and down directions. The base plate is used to connect with the bracket assembly. Among them, the bracket assembly is composed of a bracket base plate, a rotating shaft, a bracket frame, and an antenna mounting base plate; the bracket base plate is connected to the bracket frame and the support assembly, the rotating shaft is connected to the bracket base plate, and is used to position with the support assembly and drive the bracket assembly to rotate to adjust the azimuth angle; the antenna mounting base plate is connected to the bracket frame and is used for installation and positioning of the reflector antenna.

2. The device according to claim 1, wherein: The reflector antenna to be tested is positioned on the bracket assembly with pins and then installed and fixed with screws.

3. The device according to claim 1, wherein: The stent component 2 has four target points.

4. The device according to claim 1, further comprising a measuring camera for obtaining the three-dimensional coordinates of the target point.

5. The device according to claim 1, wherein: The measurement camera is located on the side of the support assembly opposite the probe.

6. A method for site calibration of a reflector antenna, using the device according to claim 1 to perform site calibration of a reflector antenna, the method comprising: S1: Install the reflector antenna on the bracket assembly and stick multiple target points on the front of the reflector antenna; S2: Take photos of the reflector antenna and the bracket assembly through the measuring camera of the photogrammetry system, measure the target points on the reflector antenna and the bracket assembly using the photogrammetry system, and calculate the coordinate value of the target point of the bracket assembly in the antenna coordinate system through common point conversion based on the coordinate value of the target point of the reflector antenna in the antenna coordinate system; S3: Target points are pasted on the site ground and the site probe. The target points on the probe can be switched between multiple positions as the site probe moves. The target points of the probe, the targets of the bracket assembly, and the site target points are photographed and tested by the camera of the photogrammetry system to obtain the coordinate conversion relationship between the probe target points and the site target points. The site coordinate system is established by the coordinates of the probe target points, and the coordinate values ​​of the site target points are obtained in the site coordinate system. S4: Take photos at multiple photogrammetry shooting points respectively, use the photogrammetry system to measure and obtain the conversion relationship between the bracket component target point and the site target point, and obtain the conversion relationship Rx, Ry, Rz between the antenna coordinate system and the site coordinate system through the coordinates of the bracket component target point in the site coordinate system; S5: According to the conversion relationship Rx, Ry, Rz between the antenna coordinate system and the ground coordinate system, adjust the bracket assembly and the adjustment module of the support assembly. After adjustment, use the photogrammetry system to measure the conversion relationship between the bracket assembly target point and the site target point, so that Rx, Ry, Rz are less than a certain threshold, meet the site calibration requirements of the antenna, and complete the first antenna site calibration.

7. The method according to claim 6, further comprising: S6: After completing the first antenna site calibration, perform the batch test site calibration step, keep the positions of the support assembly and the bracket assembly unchanged, install the reflector antenna to the bracket assembly with the positioning pins according to step S1, paste multiple target points on the front of the reflector antenna, and then directly calibrate the bracket assembly target point with the site target point to complete the site calibration.

8. The method according to claim 6, wherein: The system software is used to automatically process, identify and match the images obtained by the measuring camera. After bundle adjustment, the three-dimensional coordinates of the target point are obtained.

9. The method according to claim 6, wherein: There are 4 target points attached to the front of the reflector antenna; The target point on the probe can be switched between 4 positions as the field probe moves; there are 4 field target points on the field ground.

10. The method according to claim 6, wherein: Make Rx, Ry, Rz ≤ 0.03°.

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