The Hard-Constraint PINNs for Interface Optimal Control Problems
This addresses a specific issue in computational physics for researchers dealing with interface optimal control, offering an incremental improvement over existing PINN methods.
The authors tackled the challenge of solving optimal control problems with PDEs and interfaces using PINNs, where soft constraints cause training difficulties, by proposing a hard-constraint PINN approach that ensures exact satisfaction of boundary and interface conditions, validated on elliptic and parabolic problems.
We show that the physics-informed neural networks (PINNs), in combination with some recently developed discontinuity capturing neural networks, can be applied to solve optimal control problems subject to partial differential equations (PDEs) with interfaces and some control constraints. The resulting algorithm is mesh-free and scalable to different PDEs, and it ensures the control constraints rigorously. Since the boundary and interface conditions, as well as the PDEs, are all treated as soft constraints by lumping them into a weighted loss function, it is necessary to learn them simultaneously and there is no guarantee that the boundary and interface conditions can be satisfied exactly. This immediately causes difficulties in tuning the weights in the corresponding loss function and training the neural networks. To tackle these difficulties and guarantee the numerical accuracy, we propose to impose the boundary and interface conditions as hard constraints in PINNs by developing a novel neural network architecture. The resulting hard-constraint PINNs approach guarantees that both the boundary and interface conditions can be satisfied exactly or with a high degree of accuracy, and they are decoupled from the learning of the PDEs. Its efficiency is promisingly validated by some elliptic and parabolic interface optimal control problems.