A Method to Improve the Performance of Reinforcement Learning Based on the Y Operator for a Class of Stochastic Differential Equation-Based Child-Mother Systems
Cheng Yin, Yi Chen
TL;DR
The paper tackles optimal control for systems with stochastic dynamics described by $\\mathcal{SDE}$s, focusing on a child-mother system and the challenge of incorporating stochasticity into value-function estimation. It introduces the $\\mathcal{Y}$ operator, proven equivalent to the Itô generator $\\mathcal{A}$, to transform the time derivative of value-function functionals into partial derivatives of the drift and diffusion terms, enabling the YORL framework. The method integrates the operator into a Critic loss and uses PPO-style Actor updates, augmented by a data-driven NSDE calibration step. Across linear and nonlinear NSDE experiments, YORL outperforms traditional TSRL in convergence and final reward, with flexibility in activation choices and applicability to offline/IRL scenarios, highlighting practical impact for stochastic control with neural RL.
Abstract
This paper introduces a novel operator, termed the Y operator, to elevate control performance in Actor-Critic(AC) based reinforcement learning for systems governed by stochastic differential equations(SDEs). The Y operator ingeniously integrates the stochasticity of a class of child-mother system into the Critic network's loss function, yielding substantial advancements in the control performance of RL algorithms.Additionally, the Y operator elegantly reformulates the challenge of solving partial differential equations for the state-value function into a parallel problem for the drift and diffusion functions within the system's SDEs.A rigorous mathematical proof confirms the operator's validity.This transformation enables the Y Operator-based Reinforcement Learning(YORL) framework to efficiently tackle optimal control problems in both model-based and data-driven systems.The superiority of YORL is demonstrated through linear and nonlinear numerical examples showing its enhanced performance over existing methods post convergence.
