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)

Understanding dueling network architectures

We will now understand the use of dueling network architectures. In DQN and DDQN, and other DQN variants in the literature, the focus was primarily on algorithms, that is, how to efficiently and stably update the value function neural networks. While this is crucial for developing robust RL algorithms, a parallel but complementary direction to advance the field is to also innovate and develop novel neural network architectures that are well suited for model-free RL. This is precisely the concept behind dueling network architectures, another contribution from DeepMind.

The steps involved in dueling architectures are as follows:

  1. Dueling network architecture figure; compare with standard DQN
  2. Computing Q(s,a)
  3. Subtracting the average of the advantage from the advantage function

As we saw in the previous chapter, the output of the Q-network...