Pathfinding robot in a maze

_{Finding the shortest path outside a maze following a wall}

Documentation

Contents

---

1. Installing Webots
2. Extracting the .zip file
3. Opening the world file
4. Before running the simulation
5. Running the simulation
6. How it works
7. Editing the source code
8. Structure of the code
9. The enviroment

---

1. Installing Webots

• On Linux, run the command sudo apt install webots in terminal to install the Webots app.
• On Windows, install the official executable file from the Webots website and run it.

2. Extracting the .zip file

Extract the .zip file. It contains two folders:

• worlds folder containing the world files
• controllers folder with the actual source code for the controller of the e-puck

3. Opening the world file

To open the world file of this particular simulation you have to first

1. open Webots, then
2. go to File and
3. click the Open World button.
4. navigate then in the location where you extracted the .zip file
5. go to Worlds and
6. select one of the two simulation.

4. Before running the simulation

In some cases it may be neccesary to give running permission to the executable of the code manually.

If you run the simulation and the Webots console prompts you to do this:

• open up a console
• type $cd /location_of_the_extracted_folder/controllers/Comenzi
• then to give executing permission type chmod u+x Comenzi

5. Running the simulation

To run the simulation simply click the play button from the above or press Ctrl+2

To increase the speed of the simulation press the button next to the play button or Ctrl+3

A console should pop-up in the bottom of the screen, if not, it can be activated using Ctrl+N

Running the simulation

6. How it works

-The robot must always begin from the left side (the left wall).

-The start line and the finish line are physically denoted by two small black tapes on the floor.

-The robot has four phases:

1. Following the left wall from the start towards the finish line.
2. Once arrived at the finish line, it stores the distance from the start line to the finish using left wall. It then continues its run along the same left wall.
3. At the start line once again in stores the distance of the right wall.
4. A last run is made following the shortest wall found towards the finish line.

6. Editing the source code

If you want to change the source code, select edit from the controller menu

• Select the file you wish to edit then press open

• Edit the code then build the code by pressing the button ( don't forget to save it before)

• Press Reset the start the simulation

  7. Structure of the code

  The code is modularized in 4 different modules that are connected through an header file with the main source as shown below

  

  More about every module can be found here

  8. The enviroment

  There are two world files included in the worlds folder, each one containing a maze.

  More about the world files can be found here