基于Runge-Kutta的自回归物理信息神经网络求解偏微分方程
SELF-REGRESSIVE PHYSICS-INFORMED NEURAL NETWORK BASED ON RUNGE-KUTTA METHOD FOR SOLVING PARTIAL DIFFERENTIAL EQUATIONS
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摘要: 物理信息神经网络离散时间模型(PINN-RK)是深度学习技术与龙格库塔方法相结合的产物, 在求解偏微分方程时具有非常出色的稳定性和较高的求解精度. 但是, 受到龙格库塔算法本身的限制, PINN-RK模型仅能实现单步时间预测, 且计算效率较低. 因此, 为了实现多时间步长预测和提高模型的计算效率, 提出了一种基于龙格库塔法的自回归物理信息神经网络模型(SR-PINN-RK). 该模型基于自回归时间步进机制, 改进了神经网络的训练流程和网络结构, 相比PINN-RK模型, 大幅减少了神经网络的训练参数, 提高了模型的计算效率. 此外, 在自回归机制的作用下, 该模型通过对标签数据的动态更新, 成功实现了对偏微分方程解的多时间步长预测. 为了验证文中模型的求解精度和计算效率, 分别求解了Allen-Cahn方程和Burgers方程, 并与文献中的基准解进行了对比. 结果表明, 模型预测解与基准解之间具有很高的一致性, 求解Allen-Cahn方程和Burgers方程的最大相对误差均低于0.009.Abstract: Physics-informed neural networks discrete-time model (PINN-RK) is a product of combining deep learning techniques with Runge-Kutta method, which has excellent stability and high accuracy in solving partial differential equations. As an emerging computational tool, PINN-RK has been widely applied in solving various complex problems in scientific and engineering fields. However, due to the limitations of the Runge-Kutta algorithm itself, the PINN-RK model can only achieve single-step time prediction and has low computational efficiency. To achieve multi-step time prediction and improve the computational efficiency of the model, this paper proposes a novel self-regressive physics-informed neural networks model based on the Runge-Kutta method (SR-PINN-RK). The SR-PINN-RK model builds upon the PINN-RK model by incorporating a self-regressive time-advancing mechanism which allows the SR-PINN-RK model to learn the temporal dynamics of the partial differential equation more effectively, resulting in improved training performance and accuracy. In SR-PINN-RK model, except for the label data at the initial time given by the user, all other training labels are provided by the neural network model itself. The new PINN-RK model is a significant improvement over the PINN-RK model, with a much smaller number of training parameters and a significant boost in computational efficiency. This makes SR-PINN-RK model much faster and easier to train, while still maintaining the same level of accuracy. The SR-PINN-RK model uses a self-regressive mechanism to dynamically update the label data, which allows it to successfully achieve multi-step time prediction of partial differential equation solutions. This represents a remarkable improvement compared to the PINN-RK model, which is limited to single-step predictions. In order to verify the accuracy and computational efficiency of the SR-PINN-RK model, the Allen-Cahn equation and Burgers equation are solved using the SR-PINN-RK model and the predicted results are compared with the benchmark solutions in the literature. It is shown that the predicted solution of the SR-PINN-RK model is highly consistent with the benchmark solution qualitatively without significant differences. When it comes to the quantitative analysis, it can be observed that the maximum relative error in solving the Allen-Cahn and Burgers equations are both below 0.009, thereby exhibiting a remarkable level of precision in solving partial differential equations.