Parameterized Projected Bellman Operator: A Novel Approach in Reinforcement Learning

Основні поняття

Proposing a novel approach, the Projected Bellman Operator (PBO), learns an approximate version of the Bellman operator to improve efficiency in reinforcement learning.

Анотація

The article introduces the Parameterized Projected Bellman Operator (PBO) as an alternative approach in reinforcement learning. It addresses issues with traditional Bellman operators by learning an approximate version directly from transition samples. The PBO eliminates the need for computationally intensive projection steps and generalizes across transition samples. The article provides theoretical analysis, algorithmic implementations, and empirical results showcasing the benefits of PBO in various RL problems.

Abstract

• Approximate value iteration (AVI) aims to obtain an approximation of the optimal value function.
• The Bellman operator leverages transition samples to update value functions.
• Proposal of a novel operator, Projected Bellman Operator (PBO), to learn an approximate version of the Bellman operator.

Introduction

• Value-based RL computes value functions through iterated applications of the Bellman operator.
• Empirical Bellman operator is used when dealing with problems with unknown models.
• AVI approaches require costly function approximation steps.

Projected Bellman Operator

• PBO directly computes updated parameters of the value function without projection steps.
• Formulation of an optimization problem to learn PBO for sequential decision-making problems.
• Theoretical analysis of PBO's properties in two representative classes of RL problems.

Learning Projected Bellman Operators

• Approximation of PBO with a parameterized approach differentiable w.r.t. its parameters.
• Formulation of an empirical version of the optimization problem to optimize PBO.
• Devising algorithms for offline and online RL to learn PBO using neural network parameterizations.

Experiments

• Evaluation of ProFQI and ProDQN against their regular counterparts in offline and online settings.
• ProFQI showcases improved performance in car-on-hill problem compared to FQI.
• ProDQN demonstrates enhanced performance in bicycle balancing and lunar lander tasks.

Статистика

PBO는 최적 가치 함수의 근사값을 얻기 위한 새로운 접근 방식입니다.
AVI 접근 방식은 최적 가치 함수의 근사값을 얻기 위해 사용됩니다.
PBO는 투영 단계 없이 가치 함수의 업데이트된 매개변수를 직접 계산합니다.

Цитати

"The advantages of our approach are twofold: (i) PBO is applicable for an arbitrary number of iterations without using further samples, and (ii) the output of PBO always belongs to the considered value function space."
"We show how to estimate PBO from transition samples by leveraging a parametric approximation which we call parameterized PBO."

Ключові висновки, отримані з

Parameterized Projected Bellman Operator

by Théo... о arxiv.org 03-07-2024

https://arxiv.org/pdf/2312.12869.pdf

Глибші Запити

How does the proposed PBO approach compare to traditional Bellman operators in terms of computational efficiency and convergence speed

Proposed PBO approach offers significant advantages over traditional Bellman operators in terms of computational efficiency and convergence speed. Unlike traditional Bellman operators that require costly projection steps onto the space of action-value functions, PBO directly maps parameters of action-value functions to others. This eliminates the need for the computationally intensive projection step, leading to faster convergence and improved computational efficiency. Additionally, PBO can generate a sequence of parameters that progressively approach the optimal action-value function, allowing for more efficient learning and faster convergence to the optimal solution.

What are the potential limitations of using PBO in deep reinforcement learning with large neural networks

While PBO shows promise in reinforcement learning, there are potential limitations when applying it to deep reinforcement learning with large neural networks. One limitation is scalability, as the size of the input and output spaces of PBO depends on the number of parameters of the action-value function. This can pose challenges when dealing with deep neural networks with millions of parameters, making it difficult to scale PBO to such complex systems. Additionally, the complexity of training PBO with large neural networks may require extensive computational resources and time, limiting its practical applicability in deep reinforcement learning settings.

How can the concept of PBO be extended to other domains beyond reinforcement learning, such as optimization or control systems

The concept of PBO can be extended to other domains beyond reinforcement learning, such as optimization or control systems, by adapting the idea of directly mapping parameters to achieve desired outcomes. In optimization, PBO can be used to efficiently update parameters in iterative optimization algorithms, leading to faster convergence and improved performance. In control systems, PBO can be applied to dynamically adjust control parameters based on feedback, enabling more adaptive and efficient control strategies. By leveraging the principles of PBO in these domains, it is possible to enhance optimization processes and control systems for better performance and efficiency.