Continuous Episodic Control

Non-parametric episodic memory can be used to quickly latch onto high-reward experience in reinforcement learning tasks. In contrast to parametric deep reinforcement learning approaches, these methods only need to discover the solution once, and may then repeatedly solve the task. However, episodic control solutions are stored in discrete tables, and this approach has so far only been applied to discrete action space problems. Therefore, this paper introduces Continuous Episodic Control (CEC), a novel non-parametric episodic memory algorithm for sequential decision making in problems with a continuous action space. Results on several sparse-reward continuous control environments show that our proposed method learns faster than state-of-the-art model-free RL and memory-augmented RL algorithms, while maintaining good long-run performance as well. In short, CEC can be a fast approach for learning in continuous control tasks, and a useful addition to parametric RL methods in a hybrid approach as well.