An Online Measurement and Calibration Method for a Radio Telescope Sub-Reflector Support Structure Using Fiber Bragg Grating
The position and altitude of a sub-reflector have an important influence on the pointing accuracy of a radio telescope. With the increase of the antenna aperture, the stiffness of the support structure for the sub-reflector decreases. This causes deformation of the support structure when environment...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-05-01
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| Series: | Micromachines |
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| Online Access: | https://www.mdpi.com/2072-666X/14/5/1093 |
| _version_ | 1797598971079688192 |
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| author | Qian Xu Hong Bao |
| author_facet | Qian Xu Hong Bao |
| author_sort | Qian Xu |
| collection | DOAJ |
| description | The position and altitude of a sub-reflector have an important influence on the pointing accuracy of a radio telescope. With the increase of the antenna aperture, the stiffness of the support structure for the sub-reflector decreases. This causes deformation of the support structure when environmental loads, such as gravity, temperature, and wind load, are applied to the sub-reflector, which will seriously influence antenna pointing accuracy. This paper proposes an online measurement and calibration method for assessing the deformation of the sub-reflector support structure based on the Fiber Bragg Grating (FBG) sensors. Firstly, a reconstruction model between the strain measurements and the deformation displacements of a sub-reflector support structure is established based on the inverse finite element method (iFEM). In addition, a temperature-compensating device with an FBG sensor is designed to eliminate the effects of temperature variations on strain measurements. Considering the lack of the trained original correction, a non-uniform rational B spline (NURBS) curve is built to extend the sample data set. Next, a self-structuring fuzzy network (SSFN) is designed for calibrating the reconstruction model, which can further improve the displacement reconstruction accuracy of the support structure. Finally, a full-day experiment was carried out using a sub-reflector support model to verify the effectiveness of the proposed method. |
| first_indexed | 2024-03-11T03:29:04Z |
| format | Article |
| id | doaj.art-29954a2c7fce4c628eb76693c8a69be6 |
| institution | Directory Open Access Journal |
| issn | 2072-666X |
| language | English |
| last_indexed | 2024-03-11T03:29:04Z |
| publishDate | 2023-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Micromachines |
| spelling | doaj.art-29954a2c7fce4c628eb76693c8a69be62023-11-18T02:31:37ZengMDPI AGMicromachines2072-666X2023-05-01145109310.3390/mi14051093An Online Measurement and Calibration Method for a Radio Telescope Sub-Reflector Support Structure Using Fiber Bragg GratingQian Xu0Hong Bao1XinJiang Astronomical Observatory, Chinese Academy of Sciences, Urumqi 830011, ChinaKey Laboratory of Electronic Equipment Structure Design, Ministry of Education, Xidian University, Xi’an 710071, ChinaThe position and altitude of a sub-reflector have an important influence on the pointing accuracy of a radio telescope. With the increase of the antenna aperture, the stiffness of the support structure for the sub-reflector decreases. This causes deformation of the support structure when environmental loads, such as gravity, temperature, and wind load, are applied to the sub-reflector, which will seriously influence antenna pointing accuracy. This paper proposes an online measurement and calibration method for assessing the deformation of the sub-reflector support structure based on the Fiber Bragg Grating (FBG) sensors. Firstly, a reconstruction model between the strain measurements and the deformation displacements of a sub-reflector support structure is established based on the inverse finite element method (iFEM). In addition, a temperature-compensating device with an FBG sensor is designed to eliminate the effects of temperature variations on strain measurements. Considering the lack of the trained original correction, a non-uniform rational B spline (NURBS) curve is built to extend the sample data set. Next, a self-structuring fuzzy network (SSFN) is designed for calibrating the reconstruction model, which can further improve the displacement reconstruction accuracy of the support structure. Finally, a full-day experiment was carried out using a sub-reflector support model to verify the effectiveness of the proposed method.https://www.mdpi.com/2072-666X/14/5/1093sub-reflectorFiber Bragg Grating (FBG) sensorself-structuring fuzzy networkmeasurement model calibrationB-spline functions |
| spellingShingle | Qian Xu Hong Bao An Online Measurement and Calibration Method for a Radio Telescope Sub-Reflector Support Structure Using Fiber Bragg Grating Micromachines sub-reflector Fiber Bragg Grating (FBG) sensor self-structuring fuzzy network measurement model calibration B-spline functions |
| title | An Online Measurement and Calibration Method for a Radio Telescope Sub-Reflector Support Structure Using Fiber Bragg Grating |
| title_full | An Online Measurement and Calibration Method for a Radio Telescope Sub-Reflector Support Structure Using Fiber Bragg Grating |
| title_fullStr | An Online Measurement and Calibration Method for a Radio Telescope Sub-Reflector Support Structure Using Fiber Bragg Grating |
| title_full_unstemmed | An Online Measurement and Calibration Method for a Radio Telescope Sub-Reflector Support Structure Using Fiber Bragg Grating |
| title_short | An Online Measurement and Calibration Method for a Radio Telescope Sub-Reflector Support Structure Using Fiber Bragg Grating |
| title_sort | online measurement and calibration method for a radio telescope sub reflector support structure using fiber bragg grating |
| topic | sub-reflector Fiber Bragg Grating (FBG) sensor self-structuring fuzzy network measurement model calibration B-spline functions |
| url | https://www.mdpi.com/2072-666X/14/5/1093 |
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