基于稀疏神经核的多保真度代理模型

Exploring multi-fidelity model with sparse neural kernel

  • 摘要: 在航空航天技术领域,为平衡代理模型的训练成本与预测精度,需要发展能够有效挖掘多保真度数据间潜在相关性的建模方法。针对现有模型依赖预设核函数、缺乏数据自适应性的问题,提出了一种基于稀疏混合专家神经核(mixture of experts neural kernel, MoENK)的多保真度代理模型。MoENK通过线性混合和乘积混合基本单元构造新核函数,选择性屏蔽中间结果以过滤噪声,并应用于多任务高斯过程中。将该方法应用于算例3个函数示例和2个翼型算例中,结果表明该方法的预测精度有较大的提升,尤其在NACA0012翼型阻力系数的预测中相较于次佳方法LR-MFS的RMSE和MAE分别降低了40.42%和44.70%。证实了所提出的MoENK核函数能够不依赖预设核函数进行自适应预测,具有良好的泛化能力和鲁棒性,为工程系统的代理模型构建提供了新的工具。

     

    Abstract: Surrogate models play a crucial role in aerospace technology. To offer a trade-off between training costs and model accuracy, we introduce multi-fidelity surrogate models based on Gaussian processes. These models leverage data with varying levels of fidelity, to enhance predictive performance while simultaneously minimizing computational expenses. By integrating information from both high-fidelity and low-fidelity datasets, multi-fidelity models can achieve higher accuracy without the need for extensive high-fidelity data, which is often costly and time-consuming to obtain. However, existing multi-fidelity GP models predominantly rely on empirically predetermined kernel functions. These kernel functions are typically selected based on prior experience and general assumptions about the data, without considering the specific characteristics and underlying structures of the datasets at hand. As a result, these kernels are not tailored to the data. To overcome these challenges, this paper introduces a novel approach to constructing kernel functions that are specifically designed to uncover and exploit the latent correlations between datasets of different fidelities. To address these issues, we first propose the Mixture of Experts Neural Kernel (MoENK) which construct a more powerful kernel based on some basic kernels. In MoENK, we use two primary components: MoE-Linear and MoE-Product to selectively mask intermediate results, thereby effectively filtering out noise which may introduce negative transfer. This is then applied to multi-task Gaussian processes, which allows for the sharing of information across different fidelity levels, thereby improving the robustness and accuracy of the surrogate models. To rigorously evaluate the performance of the proposed method, we conducted a series of experiments using three benchmark function examples and two airfoil cases. It exhibited particularly notable advantages in predicting the high-dimensional drag coefficient scenario of the NACA0012 airfoil, reducing RMSE and MAE by 40.42% and 44.70%, respectively, compared to the suboptimal method, LR-MFS. These results confirm that the proposed MoENK kernel function can adaptively predict without relying on predefined kernels, offering strong generalization capabilities and robustness. This provides a new tool for constructing surrogate models in engineering systems.

     

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