Application Research On Deformation Measurement Of Antenna Array Based On Strain Measurement Technology Of Fiber Grating

During the service process of large antenna array,the structure of the array will be deformed under the influence of random pulsating wind,high temperature in extreme environment and large diameter weight,etc.,which will lead to the position deviation of the antenna unit,and then the antenna beam direction will be deflected,resulting in the deterioration of the electrical performance of the antenna.Therefore,in order to ensure the performance of the antenna in service,it is necessary to monitor the deformation of the antenna array structure and reconstruct the displacement field,so as to obtain the information of the antenna array quickly and accurately,and to compensate the electrical performance according to the deformation of the antenna.In the aspect of antenna deformation measurement,optical fiber sensing technology has the unique advantages such as high measurement accuracy,strong anti-interference ability,long signal transmission distance and so on.It makes up for the defects of traditional detection technology and is very suitable for the detection of communication optical fiber and other engineering facilities.In the field of antenna displacement field reconstruction,modal method is one of the most common methods.Modal reconstruction technology has the advantages for instance,it has stable solution and high reconstruction accuracy,and only a small amount of sensor information is needed to realize structural deformation reconstruction.This topic is on the background of real project,according to the need of real-time online monitoring antenna array surface deformation and the structure characteristics of the antenna itself,combinate the deformation measurement technology and the deformation reconstruction theory and establishes a set of on-line monitoring system,to realize the realtime feedback and fast accurate inversion of deformation of antenna structure deformation condition,moreover to achieve the purpose of the compensation for the antenna signal quantity,so as to enhance antenna detection power,improve the detection precision.The main work of this paper is as follows:First of all,according to the actual needs of the project,the strain measurement technology of the fiber grating is studied,the spectral characteristics of the fiber grating sensor and the principle of temperature compensation are analyzed,and the layout and installation plan of the fiber grating sensor are designed.On this basis,based on the strain-displacement conversion relationship of the modal method and the strain information measured by the fiber Bragg sensor,the displacement field of the antenna array was reconstructed,and the real-time online monitoring of the antenna array was realized.Secondly,Visual Studio development platform is used to complete the development of online monitoring software platform for antenna array deformation according to the design scheme.The software consists of five functional modules:(1)data transmission module: the software use Socket and demodulator protocol to realize data transceiver and remote control between the upper computer and the FBG demodulator;(2)Data processing module: based on UDP protocol,data collection,analysis and processing are realized,and modal algorithm is called to reconstruct the displacement field;(3)Data display module: real-time demonstration of data collected and arrays reconstructed in the form of tables and images respectively;(4)Database module: the software completes the design of the data table,and improves and optimizes the data storage function;(5)Device parameter configuration module: the software realizes the configuration of hardware device parameters.Finally,the on-line monitoring system of the antenna array deformation is built,and the integrated test and verification are carried out,including the accuracy verification of displacement reconstruction and the test of the function and performance of the monitoring software.The results of industrial photogrammetry which are as truth values are compared with the reconstructed results using modal method.The test results show that this monitoring scheme is feasible and has high reconstruction precision and sensitivity.