Deep Belief Nets as Function Approximators for Reinforcement Learning

We describe a continuous state/action reinforcement learning method which uses deep belief networks (DBNs) in conjunction with a value function-based reinforcement learning algorithm to learn effective control policies. Our approach is to first learn a model of the state-action space from data in an unsupervised pretraining phase, and then use neural-fitted Q-iteration (NFQ) to learn an accurate value function approximator (analogous to a “fine-tuning” phase when training DBNs for classification). Our experiments suggest that this approach has the potential to significantly increase the efficiency of the learning process in NFQ, provided care is taken to ensure the initial data covers interesting areas of the state-action space, and may be particularly useful in transfer learning settings.