| Skin antenna is a kind of high-density active phased array antenna,which integrates radio frequency components and sensing elements into various platform surface structures.Skin antenna can carry loads as well as transmit and receive electromagnetic waves which is usually mounted on the structural surfaces of aircraft,warships and armored vehicles.The surfaces of antenna array will be deformed due to wind,snow,vibration,external impact and other force majeure factors in the service environment,which will lead to serious deterioration of the electrical performance of the skin antenna.In order to solve this problem,this paper proposes a skin antenna embedded in fiber Bragg grating(FBG),which can be used as a mechanically supported mechanical structure and an antenna that transmits and receives electromagnetic waves.At the same time,deformable sensing and adaptive electrical compensation are available in service.The electrical compensation is based on the sensing of antenna array deformation,which can solve the deterioration of electrical performance caused by antenna array deformation.Therefore,this paper focuses on the deformation sensing of the antenna array,including the optimal sensor placement methods and structural deformation reconstruction method.The specific work is as follows:1.A skin antenna structure embedded with FBG is proposed.The structure and working principle of skin antenna are introduced.Based on the relationship between strain and displacement in modal method,the coupling relationship between measured strain and phase compensation is derived.Based on the coupling relation,the excitation current phase of each antenna unit is adjusted adaptively according to the measured strain of the antenna array,and the radiation pattern of the deformed skin antenna is restored to the ideal working state.2.Sequence strain sensor placement method based on modal reconstruction is proposed.In this method,the initial sensor locations are determined based on clustering criteria,and then a new location is sequentially added into the initial sensor locations one by one by minimizing the relative reconstruction error considering spatial correlation of sensor positions until the number of sensors required is obtained.The proposed method is applied to simulation experiments of a phased array experiment platform and skin antenna model,comparing CNM and EEM methods.The results show that the proposed method not only has higher computational efficiency and reduces the redundancy of sensor information,but also solves the problem of locally concentration of sensor position while ensuring the accuracy of reconstruction.3.A deformation reconstruction method based on modal-transfer learning is proposed.Compared with the modal reconstruction,the hybrid method reduces the model error between the simulation model and the real model as well as the measurement error caused by the measurement environment.In this method,the gap between the simulation model and the experimental model is initially narrowed through affine transformation,and then the deformation pseudo-prediction model of the antenna sample is obtained through adaptive weighting algorithm and ELM model.The error correction model is constructed according to the error between the pseudo-prediction model and the simulation model.The error correction model was combined with the modal reconstruction equation to establish the mixed deformation reconstruction equation.The mixed equations are applied to deformation reconstruction experiments and compared with the modal equation,the reconstruction results show that the reconstruction displacement of the mixed method is closer to the photogrammetric results,and its reconstruction accuracy is higher,which verifies the effectiveness of the proposed method for model error correction.4.The fabrication method of skin antenna sample embedded with FBG is studied.The experimental system of skin antenna for dynamic deformation reconstruction and the electric compensation system are designed,and the experimental verification of the deformation sensing and adaptive electric compensation of the antenna sample is completed.The results of experimental verify the validity of the sensor placement method and deformation reconstruction method proposed in this paper.The conclusion shows that the skin antenna embedded with FBG can be used for adaptive electrical compensation. |
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