This repository contains my Deep Reinforcement Learning solution to one of the stated problems within the scope of the following Nanodegree:

Deep Reinforcement Learning Nanodegree Program - Become a Deep Reinforcement Learning Expert

Deep Reinforcement Learning is a thriving field in AI with lots of practical applications. It consists of the use of Deep Learning techniques to be able to solve a given task by taking actions in an environment, in order to achieve a certain goal. This is not only useful to train an AI agent so as to play videogames, but also to set up and solve any environment related to any domain. In particular, as a Civil Engineer, my main area of interest is the AEC field (Architecture, Engineering & Construction).

This project consists of a Navigation problem, which is contained within the Value Based Methods chapter and is solved by means of Deep Q Learning algorithms.

The environment used for this project is based on the Unity ML-Agents Banana Collector environment from 2018. Nonetheless, the updated corresponding equivalent in 2022 would be the Food Collector Environment.

It consists of a square playground in which there exist both yellow and blue bananas. An agent must then pick the yellow ones, while discarding the blues.

Its characteristics are as follows:

• The state space has 37 dimensions and contains the agent's velocity, along with ray-based perception of objects in front of it.
• The action space consists of 4 discrete actions. Namely: move forward, move backward, turn left and turn right.
• A reward of +1 or -1 is provided when a yellow or blue banana is collected, respectively.

Firstly, the reader is advised to set up the Food Collector Environment instead of the legacy Banana Collector, specially if not following the Nanodegree. This will allow to install recent versions of the libraries and potentially avoid some unfixed bugs from old versions.

Having said that, the exact environment used in this repository for the scope of the Nanodegree can be cloned from the following repository, in which there are also the instructions to install the required dependencies: udacity/Value-based-methods

The previous cloning has been Step 1. In addition, the compressed file corresponding to the user operating system must be downloaded from one of the links below, and placed inside the ./p1_navigation/ folder after unzipping it, which constitutes Step 2:

• Linux: click here
• Mac OSX: click here
• Windows (32-bit): click here
• Windows (64-bit): click here

Once the two previous steps are accomplished, the following step (Step 3) is to clone the current repository and place the folder at the root of the freshly configured Value-based-methods. From there, it only remains to change the environment path to match the file downloaded in Step 2. This path can be changed at the following line of environment.py.

At this point, Step 4 consists of installing Seaborn within the Python environment by running pip install seaborn.

And that's it. After those four steps, the Jupyter Notebook Navigation.ipynb from this repository can already be executed.

My solution to the posed problem can be found in the Solution Report, as well as in the code included within this repository.

It is worth stating that it has been a fascinating exercise which has let me further understand the dynamics of the Deep Q Learning algorithm, along with three of its variants.