Saved in:
Bibliographic Details
Main Authors: Goertzen, Andrea, Alim, Kaveh, Min, Youngjae, Azizan, Navid
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2604.19669
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866917537400225792
author Goertzen, Andrea
Alim, Kaveh
Min, Youngjae
Azizan, Navid
author_facet Goertzen, Andrea
Alim, Kaveh
Min, Youngjae
Azizan, Navid
contents Enforcing constraint satisfaction in neural network outputs is critical for safety, reliability, and physical fidelity in many control and decision-making applications. While soft-constrained methods penalize constraint violations during training, they do not guarantee constraint adherence during inference. Other approaches guarantee constraint satisfaction via a projection layer, but often rely on the existence of a tractable projection onto the feasible set, limiting their utility in more general problem settings. Many real-world problems of interest are nonlinear and lack the special structure admitting a tractable projection, motivating the development of methods that can enforce general nonlinear constraints. To this end, we introduce HardNet++, a constraint-satisfaction method that enforces linear and nonlinear equality and inequality constraints. Our approach iteratively adjusts the network output via damped local linearizations of the constraints. Each iteration is differentiable, admitting an end-to-end training framework, where the constraint satisfaction layer is active during training. We show that under certain regularity conditions, this procedure enforces nonlinear constraint satisfaction to arbitrary tolerance. Finally, we demonstrate tight constraint adherence without loss of optimality in a learning-for-optimization context, where we apply this method to a nonlinear model predictive control problem.
format Preprint
id arxiv_https___arxiv_org_abs_2604_19669
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle HardNet++: Nonlinear Constraint Enforcement in Neural Networks
Goertzen, Andrea
Alim, Kaveh
Min, Youngjae
Azizan, Navid
Machine Learning
Enforcing constraint satisfaction in neural network outputs is critical for safety, reliability, and physical fidelity in many control and decision-making applications. While soft-constrained methods penalize constraint violations during training, they do not guarantee constraint adherence during inference. Other approaches guarantee constraint satisfaction via a projection layer, but often rely on the existence of a tractable projection onto the feasible set, limiting their utility in more general problem settings. Many real-world problems of interest are nonlinear and lack the special structure admitting a tractable projection, motivating the development of methods that can enforce general nonlinear constraints. To this end, we introduce HardNet++, a constraint-satisfaction method that enforces linear and nonlinear equality and inequality constraints. Our approach iteratively adjusts the network output via damped local linearizations of the constraints. Each iteration is differentiable, admitting an end-to-end training framework, where the constraint satisfaction layer is active during training. We show that under certain regularity conditions, this procedure enforces nonlinear constraint satisfaction to arbitrary tolerance. Finally, we demonstrate tight constraint adherence without loss of optimality in a learning-for-optimization context, where we apply this method to a nonlinear model predictive control problem.
title HardNet++: Nonlinear Constraint Enforcement in Neural Networks
topic Machine Learning
url https://arxiv.org/abs/2604.19669