Bayesian Generational Population-Based Training

Abstract

Reinforcement learning (RL) offers the potential for training generally capable agents that can interact autonomously in the real world. However, one key limitation is the brittleness of RL algorithms to core hyperparameters and network architecture choice. Furthermore, non-stationarities such as evolving training data and increased agent complexity mean that different hyperparameters and architectures may be optimal at different points of training. This motivates AutoRL, a class of methods seeking to automate these design choices. One prominent class of AutoRL methods is Population-Based Training (PBT), which have led to impressive performance in several large scale settings. In this paper, we introduce two new innovations in PBT-style methods. First, we employ trust-region based Bayesian Optimization, enabling full coverage of the high-dimensional mixed hyperparameter search space. Second, we show that using a generational approach, we can also learn both architectures and hyperparameters jointly on-the-fly in a single training run. Leveraging the new highly parallelizable Brax physics engine, we show that these innovations lead to dramatic performance gains, significantly outperforming the tuned baseline while learning entire configurations on the fly.

Publication
Proceedings of the 1st International Conference on Automated Machine Learning

A preliminary version of this paper appeared at the ICLR 2022 Workshop on Agent Learning in Open-Endedness (ALOE).

This work was featured in the AutoML Seminars.

Xingchen Wan
Xingchen Wan
Research Scientist

My research interests include Bayesian optimization, AutoML, graphs & large language models.