RePReL: Integrating Relational Planning and Reinforcement Learning for Effective Abstraction

Published in "To appear in the Proceedings of the 31st International Conference on Automated Planning and Scheduling"
Harsha Kokel , Arjun Manoharan , Sriraam Natarajan , Balaraman Ravindran , Prasad Tadepalli

State abstraction is necessary for better task transfer in complex reinforcement learning environments. Inspired by the benefit of state abstraction in MAXQ and building upon hybrid planner-RL architectures, we propose RePReL, a hierarchical framework that leverages a relational planner to provide useful state abstractions. Our experiments demonstrate that the abstractions enable faster learning and efficient transfer across tasks. More importantly, our framework enables the application of standard RL approaches for learning in structured domains. The benefit of using the state abstractions is critical in relational settings, where the number and/or types of objects are not fixed apriori. Our experiments clearly show that RePReL framework not only achieves better performance and efficient learning on the task at hand but also demonstrates better generalization to unseen tasks.