## 1 Introduction
[PERSON] [19] used the 3D LDV to achieve single-point and surface quality assessment of continuous production, but at the same time, he pointed out that the 3D LDV can be especially useful for measurements of small, lightweight, or very fragile elements. In addition, non-contact test systems such as 3D LDV are more expensive and have higher requirements on the environment during use, so they are mainly used in indoor testing. At present, the contact test such as an accelerometer is still used in the vibration test of indoor and outdoor testing for large structures [20,21]. The modal frequency has the advantages of easy measurement, accuracy and reflecting the global characteristics of the structure. However, because it is difficult to excite the high-order modes in the actual testing of large structures such as offshore platforms, only the low-order modes can be obtained. When the updating parameters are too many, the ill-posed problem of the modified equation will be caused [22]. Therefore, it is necessary to increase other characteristic quantities to ensure the satisfiability of the modified equation. Although the direct or indirect use of the mode shape is a good supplement to the modal frequency, for the actual large-scale complex structures such as offshore platforms, it is impossible to arrange too many measuring points due to the limitations of test conditions such as underwater structure, and there is the computational mode reduction or the experimental mode expansion in the updating process, which causes correction errors. Although the antiresonant frequencies [23] were originally applied to mechanical structure vibration reduction, it was gradually applied to the finite element model updating because it has the advantages of easy testing and accurate results as the resonance frequency, and it varies with the location of measuring points to reflect the local information of the structure [24, 25, 26]. However, the current methods are mainly based on theoretical research and a small number of experimental verification studies with multiple measurement points,which do not meet the application needs of actual large complex structures. In the study of optimization algorithms, [PERSON] [27] concludes that the iterative method can obtain more accurate updating results than the direct method. Sensitivity analysis is a common iterative method. However, it is difficult to effectively express the mapping relationship between the modified parameters and the characteristic quantities in the updating process by functional expression, and the high-dimensional and nonlinear optimization problems need to be solved in the iterative process, which is prone to problems such as the low computational efficiency and falling into the local optimal solutions [28]. Artificial neural networks (ANN) have recently been introduced as an alternative to optimization algorithms [29; 30]. In the application of model updating, [PERSON] and [PERSON]. [31] studied the structural damage assessment based on ANN and antiresonance frequencies with an 8-DOF mass-spring system. He pointed out that antiresonant frequencies can be identified more easily and more accurately than mode shapes. However, he only used the seven antiresonant frequencies identified by the point frequency response function of the first mass as the characteristic quantities of the objective function. Although good results are achieved, it is difficult to apply to large structures that can only be excited by the low-order modes. Detailed information about the method of using ANN to update the structural finite element model is shown in Ref. [1]. Among them, the radial basis function (RBF) neural network is applied to finite element model updating due to its advantages such as the short training time, high prediction accuracy, as well as the ability to withstand the presence of noise in experimental data and approximate any continuous functions with arbitrary precision [32; 33].