Book Image

TensorFlow Reinforcement Learning Quick Start Guide

By : Kaushik Balakrishnan
Book Image

TensorFlow Reinforcement Learning Quick Start Guide

By: Kaushik Balakrishnan

Overview of this book

Advances in reinforcement learning algorithms have made it possible to use them for optimal control in several different industrial applications. With this book, you will apply Reinforcement Learning to a range of problems, from computer games to autonomous driving. The book starts by introducing you to essential Reinforcement Learning concepts such as agents, environments, rewards, and advantage functions. You will also master the distinctions between on-policy and off-policy algorithms, as well as model-free and model-based algorithms. You will also learn about several Reinforcement Learning algorithms, such as SARSA, Deep Q-Networks (DQN), Deep Deterministic Policy Gradients (DDPG), Asynchronous Advantage Actor-Critic (A3C), Trust Region Policy Optimization (TRPO), and Proximal Policy Optimization (PPO). The book will also show you how to code these algorithms in TensorFlow and Python and apply them to solve computer games from OpenAI Gym. Finally, you will also learn how to train a car to drive autonomously in the Torcs racing car simulator. By the end of the book, you will be able to design, build, train, and evaluate feed-forward neural networks and convolutional neural networks. You will also have mastered coding state-of-the-art algorithms and also training agents for various control problems.
Table of Contents (11 chapters)

Chapter 1

  1. A replay buffer is required for off-policy RL algorithms. We sample from the replay buffer a mini-batch of experiences and use it to train the Q(s,a) state-value function in DQN and the actor's policy in a DDPG.
  2. We discount rewards, as there is more uncertainty about the long-term performance of the agent. So, immediate rewards have a higher weight, a reward earned in the next time step has a relatively lower weight, a reward earned in the subsequent time step has an even lower weight, and so on.
  3. The training of the agent will not be stable if γ > 1. The agent will fail to learn an optimal policy.
  4. A model-based RL agent has the potential to perform well, but there is no guarantee that it will perform better than a model-free RL agent, as the model of the environment we are constructing need not always be a good one. It is also very hard to build an accurate...