🤖 AI Summary
This study addresses the limitation of conventional port-Hamiltonian neural networks, which can represent only a single attractor and thus fail to model multistable systems. We propose a modeling framework that supports multiple asymptotically stable equilibria by parameterizing the Hamiltonian as a product of Bregman divergences. By integrating input-convex neural networks with port-Hamiltonian theory, our approach overcomes the restriction to a single global minimum. We rigorously establish local Lyapunov stability and almost-everywhere convergence. Experimental results demonstrate that the proposed model successfully recovers the characteristics of multistable energy landscapes, achieving convergence speeds 1.8 to 8.5 times faster than baseline methods.
📝 Abstract
Stable port-Hamiltonian neural networks certify asymptotic stability by construction. Yet, their Hamiltonian is a global Lyapunov function with a single global minimum, so they can represent only dynamic systems with {one} attractor. We demonstrate that this excludes even simple systems with energy landscapes forming a double well, and we overcome the restriction by parametrising the Hamiltonian as a {product} of Bregman divergences generated by one input-convex network. We prove that the resulting model is locally Lyapunov stable, that the coexistence of stable equilibria forces additional non-asymptotically-stable equilibria to exist, that all equilibria lie in a bounded region, and under a hyperbolicity assumption that almost-everywhere stability holds. On three systems our approach is able to recover the energy surface characteristics and improve the convergence speed by 1.8$\times$-8.5$\times$.