A double-inverse terahertz tight-field assembly error compensation method

Abstract

The application relates to a double-reflection terahertz tight-field assembly error compensation method, which comprises the following steps: assembling a main support structure, removing assembly stress through high-temperature aging; installing a main reflector on the main support structure and calibrating the main reflector; marking the current position of the main reflector on a reference mirror on the side of the main reflector, establishing a test coordinate system based on the reference mirror; installing a secondary reflector mounting bottom plate on the main support structure, installing a secondary reflector on the secondary reflector mounting bottom plate and calibrating the secondary reflector; calculating the offset of the final position of a feed source assembly relative to the theoretical position of the feed source assembly; taking the main reflector as a reference, adjusting the position of the feed source assembly based on the offset by using a high-precision six-degree-of-freedom platform so that the feed source assembly is located at the final position. The application effectively reduces the assembly and calibration difficulty of the secondary reflector, and makes the final assembly and calibration precision of the terahertz tight-field system equivalent to the test precision of an optical test instrument, that is, the highest precision that can be achieved.

Description

Technical Field

[0001] This application relates to the field of electronics and communications, and more specifically, to a method for compensating assembly errors in a dual-anti-terahertz compact field. Background Technology

[0002] Terahertz compact fields are used for testing terahertz antennas. Because terahertz compact fields operate at high frequencies, they require high precision in system installation and calibration. A dual-reflector terahertz compact field, for example, comprises a primary reflector, a secondary reflector, and a feed assembly. The final quiet zone performance of the compact field is highly sensitive to the relative positions of these three components, thus demanding high precision in their installation and calibration. Current technologies present significant engineering challenges and insufficient calibration accuracy in compensating for assembly errors in dual-reflector terahertz compact fields. Summary of the Invention

[0003] To overcome at least one deficiency in the prior art, this application provides a dual-anti-terahertz compaction field assembly error compensation method.

[0004] Firstly, a method for compensating assembly errors using a dual-reverse terahertz compact field is provided, comprising:

[0005] Assemble the main support structure and remove assembly stress through high-temperature aging;

[0006] The main reflector is installed on the main support structure and calibrated to an accuracy of 0.05° rotation angle and 1mm displacement.

[0007] The current position of the primary reflector is calibrated onto the reference mirror on the side of the primary reflector, and a test coordinate system is established based on the reference mirror;

[0008] A secondary reflector mounting plate is installed on the main support structure, the secondary reflector is installed on the secondary reflector mounting plate, and the secondary reflector is calibrated to a rotation angle of 0.05° and a displacement of 1mm.

[0009] Calculate the offset of the final position of the feed component relative to the theoretical position of the feed component;

[0010] Using the main reflector as a reference, a high-precision six-degree-of-freedom platform is used to adjust the position of the feed component based on the offset, so that the feed component is in the final position.

[0011] In one embodiment, the offset of the final position of the feed component relative to its theoretical position is calculated using the following formula:

[0012]

[0013]

[0014] dz=kz (dx s +2Lsin(dθ / 2) 2 )

[0015] Where (dx, dy, dz) are offsets, dx, dy, and dz are the offsets in the x, y, and z axes of the test coordinate system, respectively, and k x k y k z These are the displacement compensation coefficients along the x, y, and z axes in the test coordinate system, respectively, dx s dy s dz s Let dθ be the displacement deviation of the sub-reflector in the x, y, and z axes of the test coordinate system, and dθ be the angular deviation of the sub-reflector. Let L be the direction of the angular deviation, and L be the distance from the fitting focus of the primary reflector to the origin of the test coordinate system.

[0016] In one embodiment, the feed assembly is provided with a calibration hole, which is located on the conical cylindrical plane that is integrally machined with a square-round transition. The calibration hole is used to characterize the position of the feed assembly.

[0017] In one embodiment, a reference hole is provided at the edge of the main reflector to characterize the position of the main reflector.

[0018] Compared with the prior art, this application has the following beneficial effects:

[0019] 1. A high-precision six-degree-of-freedom turntable is used to adjust the feed position, achieving an adjustment accuracy of 0.001° and 0.001mm for the feed angle and displacement, respectively. This ensures that the actual position of the feed assembly matches the theoretical value, thereby relaxing the adjustment accuracy of the heavier sub-reflector's angle and displacement from the required 0.02° and 0.2mm to 0.05° and 1mm. The actual position installation error of the sub-reflector is compensated by the new theoretical position value of the feed assembly. This application effectively reduces the difficulty of sub-reflector assembly and calibration, and makes the final assembly and calibration accuracy of the terahertz compressed field system equivalent to the testing accuracy of optical testing instruments, achieving the highest achievable accuracy.

[0020] 2. A reference mirror is installed on the side of the main reflector, which has a good optical measurement field of view and does not block the radio frequency signal. This mirror is used to characterize the actual position of the main reflector after installation and to represent the calibration coordinate system. Using the reference mirror on the side of the main reflector as the calibration reference can minimize the difficulty of installing and calibrating the main reflector. Attached Figure Description

[0021] This application can be better understood by referring to the description given below in conjunction with the accompanying drawings, which, together with the detailed description below, are incorporated in and form part of this specification. In the drawings:

[0022] Figure 1 A flowchart of the assembly error compensation method for dual-reverse terahertz compression field is shown. Detailed Implementation

[0023] Exemplary embodiments of the present application will be described below with reference to the accompanying drawings. For clarity and brevity, not all features of the actual embodiments are described in the specification. However, it should be understood that many embodiment-specific decisions can be made in the development of any such actual embodiment to achieve the developer’s specific objectives, and these decisions may vary as the embodiments differ.

[0024] It should also be noted that, in order to avoid obscuring this application with unnecessary details, only the device structure closely related to the solution according to this application is shown in the accompanying drawings, while other details that are not closely related to this application are omitted.

[0025] It should be understood that this application is not limited to the described embodiments by virtue of the following description with reference to the accompanying drawings. In this document, embodiments may be combined with each other, features may be substituted or borrowed between different embodiments, and one or more features may be omitted in one embodiment, where feasible.

[0026] This application provides a method for compensating assembly errors using a dual-reverse terahertz compact field. Figure 1 A flowchart of the dual-reverse terahertz compact field assembly error compensation method is shown. See [link / reference]. Figure 1 The methods include:

[0027] Step S1: Assemble the main support structure and remove assembly stress through high-temperature aging.

[0028] Pre-assembly and formal installation calibration can be performed before the formal assembly of the main support structure in step 1.

[0029] Pre-assembly includes:

[0030] The main reflector, sub-reflector, feed assembly, and their six-degree-of-freedom turntable are mounted on the main support structure. The relative position accuracy is tested to see if it meets the calibration accuracy requirements. If the adjustment links reserved for all components cannot meet the calibration size requirements, the mounting interface needs to be modified. If the requirements are met, the RF component pre-assembly work can be carried out.

[0031] To verify the stability of the double-reflector shaped compaction field under gravity conditions, the pre-assembly and calibration of the main reflector, sub-reflector, and feed assembly were completed. After assembly, the main support structure was fixed with feet. The relative positional relationship of the main reflector, sub-reflector, and feed assembly was tested at least three times using an optical measuring device. Then, the entire compaction field system was left to stand still for 3-5 days. The relative position of the main reflector, sub-reflector, and feed assembly was re-measured using an optical measuring device at least three times. If the overall structure remained stable and the rotation angle and displacement errors of each component were within the allowable range, it indicates that the main support structure has good stability under full load conditions.

[0032] Formal installation and calibration include:

[0033] The pointing coordinate system of the shaped dual-reflector terahertz compact field is consistent with the coordinate system of the main reflector. Considering the high stiffness and high stability of the main reflector, a reference mirror is provided on the side of the main reflector to characterize the pointing of the main reflector and the compact field.

[0034] The sub-reflector and feed assembly are installed and calibrated with the main reflector as the reference. At the same time, a six-degree-of-freedom high-precision turntable is installed below the feed assembly, with an angle adjustment accuracy of mdeg and a displacement adjustment accuracy on the order of μm. The adjustment error is almost negligible. At this time, the pointing and displacement deviation of the sub-reflector can be compensated by precisely adjusting the installation position of the feed. Therefore, the requirements for the sub-reflector's 0.02° rotation accuracy and 0.2mm displacement accuracy can be relaxed.

[0035] Step S2: Install the main reflector on the main support structure and calibrate the main reflector to achieve a rotation angle of 0.05° and a displacement of 1mm.

[0036] The main reflector is large and heavy, making it the most difficult to operate and requiring hoisting. However, considering that the main reflector itself is the calibration benchmark for the test, the calibration accuracy requirement does not need to be too high. After calibrating the main reflector to an accuracy of 0.05° rotation and 1mm displacement, pin positioning can be used to ensure the pointing position.

[0037] Step S3: The current position of the main reflector is calibrated onto the reference mirror on the side of the main reflector. A test coordinate system is established based on the reference mirror, and the calibration accuracy is the test accuracy of the test instrument.

[0038] Specifically, a reference hole is provided at the edge of the main reflector to characterize the position of the main reflector.

[0039] Step S4: Install the sub-reflector mounting plate on the main support structure, install the sub-reflector on the sub-reflector mounting plate, and calibrate the sub-reflector to an accuracy of 0.05° rotation angle and 1mm displacement.

[0040] Since both the mounting base plate holes and the sub-reflector mounting holes are machined by CNC machine tools and have high positional accuracy, ensuring the positional accuracy of the mounting base plate first will greatly help with the subsequent calibration and adjustment of the sub-reflector.

[0041] The subreflector was calibrated using a calibration fixture and the adjusting bolts on the back of the subreflector. After the accuracy reached 0.05° rotation angle and 1mm displacement, the pin was used for positioning, and the calibration accuracy of the system was retested.

[0042] Specifically, the sub-reflector calibration reference (calibration ball) is set on the mounting base plate, and multiple calibration balls are set. This not only ensures the test accuracy but also increases the observation range.

[0043] Step S5: Calculate the offset of the final position of the feed component relative to the theoretical position of the feed component.

[0044] Specifically, the offset of the final position of the feed component relative to its theoretical position is calculated using the following formula:

[0045]

[0046]

[0047] dz=k z (dz s +2Lsin(dθ / 2) 2 )

[0048] Where (dx, dy, dz) are offsets, dx, dy, and dz are the offsets in the x, y, and z axes of the test coordinate system, respectively, and k x k y k z dx represents the displacement compensation coefficients in the x, y, and z axes of the test coordinate system, obtained through numerical analysis. s dy s dz s dθ represents the displacement deviation of the sub-reflector in the x, y, and z axes of the test coordinate system, obtained by measurement, while dθ represents the angular deviation of the sub-reflector. Let L be the direction of the angular deviation, and L be the distance from the fitting focus of the primary reflector to the origin of the test coordinate system.

[0049] Step S6: Using the main reflector as a reference, a high-precision six-degree-of-freedom platform is used to adjust the position of the feed component based on the offset so that the feed component is in the final position.

[0050] Here, given the theoretical position of the feed component, adjusting the position of the feed component according to the offset will bring the feed component to its final position.

[0051] Specifically, the feed assembly is provided with calibration holes, which are set on the conical cylindrical plane that is integrally machined with a square-round transition. The calibration holes are used to characterize the position of the feed assembly.

[0052] In summary, this application has the following technical effects:

[0053] 1. A high-precision six-degree-of-freedom turntable is used to adjust the feed position, achieving an adjustment accuracy of 0.001° and 0.001mm for the feed angle and displacement, respectively. This ensures that the actual position of the feed assembly matches the theoretical value, thereby relaxing the adjustment accuracy of the heavier sub-reflector's angle and displacement from the required 0.02° and 0.2mm to 0.05° and 1mm. The actual position installation error of the sub-reflector is compensated by the new theoretical position value of the feed assembly. This application effectively reduces the difficulty of sub-reflector assembly and calibration, and makes the final assembly and calibration accuracy of the terahertz compressed field system equivalent to the testing accuracy of optical testing instruments, achieving the highest achievable accuracy.

[0054] 2. A reference mirror is installed on the side of the main reflector, which has a good optical measurement field of view and does not block the radio frequency signal. This mirror is used to characterize the actual position of the main reflector after installation and to represent the calibration coordinate system. Using the reference mirror on the side of the main reflector as the calibration reference can minimize the difficulty of installing and calibrating the main reflector.

[0055] The above descriptions are merely various embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for compensating assembly errors in a dual-reverse terahertz compact field, characterized in that, include: Assemble the main support structure and remove assembly stress through high-temperature aging; A main reflector is installed on the main support structure, and the main reflector is calibrated to a rotation angle of 0.05° and a displacement of 1mm. The current position of the main reflector is calibrated onto the reference mirror on the side of the main reflector, and a test coordinate system is established based on the reference mirror; A secondary reflector mounting base plate is installed on the main support structure, a secondary reflector is installed on the secondary reflector mounting base plate, and the secondary reflector is calibrated to a rotation angle of 0.05° and a displacement of 1mm. The offset of the final position of the feed component relative to its theoretical position is calculated using the following formula: in, （ ） This is the offset. In the test coordinate system Offsets in the y and z axes 、 、 In the test coordinate system y, z Displacement compensation coefficient in the axial direction, 、 For the sub-reflector in the test coordinate system y, z Displacement deviation in the axial direction This is the angular deviation of the subreflector. In terms of the direction of angular deviation, The distance from the fitting focus of the main reflector to the origin of the test coordinate system; Using the main reflector as a reference, a high-precision six-degree-of-freedom platform is used to adjust the position of the feed component based on the offset so that the feed component is in the final position.

2. The method as described in claim 1, characterized in that, The feed assembly is provided with a calibration hole, which is set on the conical cylindrical plane that is integrally machined with a square-round transition. The calibration hole is used to characterize the position of the feed assembly.

3. The method as described in claim 1, characterized in that, A reference hole is provided on the edge of the main reflector to characterize the position of the main reflector.

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