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arXiv · 1903.04193

Sample-Efficient Model-Free Reinforcement Learning with Off-Policy Critics

Denis Steckelmacher·Hélène Plisnier·Diederik M. Roijers·Ann Nowé
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Abstract

Value-based reinforcement-learning algorithms provide state-of-the-art results in model-free discrete-action settings, and tend to outperform actor-critic algorithms. We argue that actor-critic algorithms are limited by their need for an on-policy critic. We propose Bootstrapped Dual Policy Iteration (BDPI), a novel model-free reinforcement-learning algorithm for continuous states and discrete actions, with an actor and several off-policy critics. Off-policy critics are compatible with experience replay, ensuring high sample-efficiency, without the need for off-policy corrections. The actor, by slowly imitating the average greedy policy of the critics, leads to high-quality and state-specific exploration, which we compare to Thompson sampling. Because the actor and critics are fully decoupled, BDPI is remarkably stable, and unusually robust to its hyper-parameters. BDPI is significantly more sample-efficient than Bootstrapped DQN, PPO, and ACKTR, on discrete, continuous and pixel-based tasks. Source code: https://github.com/vub-ai-lab/bdpi.

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Denis Steckelmacher, Hélène Plisnier, Diederik M. Roijers, Ann Nowé. 2019-03-11. Sample-Efficient Model-Free Reinforcement Learning with Off-Policy Critics. https://arxiv.org/abs/1903.04193

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