HJ inequalities involving Lie brackets and feedback stabilizability with cost regulation

TL;DR

This paper introduces a generalized control Lyapunov function involving Lie brackets and cost considerations, enabling feedback stabilization with cost regulation for control systems.

Contribution

It extends classical dissipative relations to a weaker differential inequality involving Lie brackets and cost, defining degree-k Minimum Restraint Functions for stabilization.

Findings

Existence of degree-k Minimum Restraint Functions implies stabilizability.

Provides a Lie-bracket-based feedback law for stabilization.

Ensures uniform cost regulation during stabilization.

Abstract

With reference to an optimal control problem where the state has to approach asymptotically a closed target while paying a non-negative integral cost, we propose a generalization of the classical dissipative relation that defines a Control Lyapunov Function to a weaker differential inequality. The latter involves both the cost and the iterated Lie brackets of the vector fields in the dynamics up to a certain degree k greater than or equal to 1, and we call any of its (suitably defined) solutions a degree-k Minimum Restraint Function. We prove that the existence of a degree-k Minimum Restraint Function allows us to build a Lie-bracket-based feedback which sample stabilizes the system to the target while regulating (i.e., uniformly bounding) the cost.