Learning from Less: Guiding Deep Reinforcement Learning with Differentiable Symbolic Planning

TL;DR

This paper introduces Dylan, a differentiable symbolic planner that integrates human priors into reinforcement learning, improving efficiency, exploration, and generalization in complex tasks.

Contribution

Dylan uniquely combines symbolic planning with RL to shape rewards and generate policies, enabling more efficient learning and better generalization.

Findings

Dylan improves RL performance across various tasks.

It enables RL agents to learn with fewer interactions.

Dylan enhances generalization to unseen tasks.

Abstract

When tackling complex problems, humans naturally break them down into smaller, manageable subtasks and adjust their initial plans based on observations. For instance, if you want to make coffee at a friend's place, you might initially plan to grab coffee beans, go to the coffee machine, and pour them into the machine. Upon noticing that the machine is full, you would skip the initial steps and proceed directly to brewing. In stark contrast, state of the art reinforcement learners, such as Proximal Policy Optimization (PPO), lack such prior knowledge and therefore require significantly more training steps to exhibit comparable adaptive behavior. Thus, a central research question arises: \textit{How can we enable reinforcement learning (RL) agents to have similar ``human priors'', allowing the agent to learn with fewer training interactions?} To address this challenge, we propose differentiable symbolic planner (Dylan), a novel framework that integrates symbolic planning into Reinforcement Learning. Dylan serves as a reward model that dynamically shapes rewards by leveraging human priors, guiding agents through intermediate subtasks, thus enabling more efficient exploration. Beyond reward shaping, Dylan can work as a high level planner that composes primitive policies to generate new behaviors while avoiding common symbolic planner pitfalls such as infinite execution loops. Our experimental evaluations demonstrate that Dylan significantly improves RL agents' performance and facilitates generalization to unseen tasks.