Skip to content
Preprint

Policy Iteration for Linear-Quadratic Stochastic Differential Games with State- and Control-Dependent Noise

Aug 2026 · 1 citation · 43 references
Engineering Computer Science

TL;DR

The resulting characterization reveals how control-dependent noise, policy-evaluation sensitivity, and update ordering govern local error propagation, and yields explicit sufficient conditions for local linear convergence.

Abstract

This paper presents a novel sequential policy iteration (PI) method for stochastic differential games with state- and control-dependent noise. The updates preserve mean-square stability, so that the iteration is well posed. We further derive a closed-form expression for the Fr\'echet derivative of the sequential PI map at a Nash equilibrium. The resulting characterization reveals how control-dependent noise, policy-evaluation sensitivity, and update ordering govern local error propagation, and yields explicit sufficient conditions for local linear convergence. Since finding an initial stabilizing solution is a major challenge in policy iteration, we also propose a homotopy-based initialization that ensures a valid starting point. The effectiveness of the proposed PI algorithm and the analytical results are verified through a numerical example.

View source

Similar papers

Preprint Aug 2026

Infinite-Horizon Inverse Linear-Quadratic Differential Games with State- and Control-Dependent Noise

This paper presents a method to solve the inverse problem for N-player infinite-horizon linear-quadratic (LQ) differential games with state- and control-dependent noise. For this stochastic setting, we derive necessary and sufficient conditions for linear feedback Nash equilibria, which take the form of coupled stochas...

Lucas Günther, Karl Handwerker, Felix Thömmes et al. · 1 citation
Preprint Aug 2026

Stabilizer Design for Policy Iteration in Stochastic Linear Quadratic Control: A Spectrum-Assignment Approach

A novel spectrum assignment method is proposed to obtain an initial stabilizer for PI in continuous-time indefinite stochastic linear quadratic control with the help of the Lyapunov-type operator's spectrum, which is gradually approximated from the stable auxiliary system by adjusting a cumulative factor, thereby obtai...

Xinyu Cao, Bing-Chang Wang, Ying Cao · 0 citations
Preprint Sep 2026

Policy Iteration for Domain Randomized Linear Quadratic Systems

In this work, we study policy optimization under domain randomization for linear quadratic control, focusing on learning a single state-feedback controller that minimizes the average cost across systems with uncertain dynamics. We propose a policy iteration algorithm with a step-size rule that preserves stability acros...

Abbas Pasdar, F. Yaghmaie · 0 citations
Sep 2026

Carleman approximation based adaptive optimal control design of nonlinear systems: A three-phase policy iteration approach.

A novel adaptive optimal controller design scheme for continuous-time nonlinear systems through neural network-based policy iteration through Carleman linearization, which allows the optimal feedback control to be derived from a state-dependent Riccati (SDR) equation rather than the Hamilton-Jacobi-Bellman equation.

Jian-Guo Zhao, Zhi-Jiang Gao, Chun-Yu Yang et al. · 0 citations
Preprint Sep 2026

Critic-Free Policy Iteration for Continuous-Time Zero-Sum Games: A Policy-Space Riccati Approach

This paper develops a critic-free policy iteration (PI) method for continuous-time linear zero-sum games. The central idea is to characterize the saddle-point policies directly in the joint policy space, rather than treating the quadratic value matrix as an iterative variable. A policy game Riccati equation (PGRE) is i...

Jia-Cheng Wu, Yang Zhu, Hong-Ye Su · 0 citations

We use cookies to run the site and, with your consent, for analytics and to show ads. See our Cookie Policy.