Saved in:
Bibliographic Details
Main Authors: Jones, Morgan, Peet, Matthew
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2502.15421
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866918404723572736
author Jones, Morgan
Peet, Matthew
author_facet Jones, Morgan
Peet, Matthew
contents Optimal feedback controllers for nonlinear systems can be derived by solving the Hamilton-Jacobi-Bellman (HJB) equation. However, because the HJB is a nonlinear partial differential equation, numerical methods typically provide only approximate solutions. While numerical error bounds on approximate HJB solutions are often available, these bounds do not necessarily translate into guarantees on the suboptimality of the resulting controllers. In this paper, we establish that the suboptimality of the resulting controller is bounded by the $L^\infty$ norm of the HJB residual, which is, in turn, bounded by numerical error in the value function as measured in the Sobolev $W^{1,\infty}$ norm. This implies that convergence of value functions in $W^{1,\infty}$ result in controllers that yield a cost that is arbitrarily close to the true minimum. In contrast, we demonstrate that such guarantees do not hold when the value function error is measured in weaker norms, such as the Sobolev $W^{1,p}$ norm for finite $p$. These results apply to systems governed by Lipschitz continuous dynamics over a finite time horizon with compact input space.
format Preprint
id arxiv_https___arxiv_org_abs_2502_15421
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Bounding the Error of Value Functions in Sobolev Norm Yields Bounds on Suboptimality of Controller Performance
Jones, Morgan
Peet, Matthew
Optimization and Control
Optimal feedback controllers for nonlinear systems can be derived by solving the Hamilton-Jacobi-Bellman (HJB) equation. However, because the HJB is a nonlinear partial differential equation, numerical methods typically provide only approximate solutions. While numerical error bounds on approximate HJB solutions are often available, these bounds do not necessarily translate into guarantees on the suboptimality of the resulting controllers. In this paper, we establish that the suboptimality of the resulting controller is bounded by the $L^\infty$ norm of the HJB residual, which is, in turn, bounded by numerical error in the value function as measured in the Sobolev $W^{1,\infty}$ norm. This implies that convergence of value functions in $W^{1,\infty}$ result in controllers that yield a cost that is arbitrarily close to the true minimum. In contrast, we demonstrate that such guarantees do not hold when the value function error is measured in weaker norms, such as the Sobolev $W^{1,p}$ norm for finite $p$. These results apply to systems governed by Lipschitz continuous dynamics over a finite time horizon with compact input space.
title Bounding the Error of Value Functions in Sobolev Norm Yields Bounds on Suboptimality of Controller Performance
topic Optimization and Control
url https://arxiv.org/abs/2502.15421