Wall-follower-in-ROS-using-Python

This was my final project for a robotics course in UMD. (ENPM809E - Python Applications for Robotics)

This algorithm was implemented using the Robot Operating System (ROS) libraries, Gazebo as simulator and Python as programming language.

Task

The goal of this project is to solve a maze problem using only one Turtlebot 3 robot which comes equipped with a laser scanner.

We had to achieve the following tasks:

• Detect a wall
• Follow the wall
• Avoid collision with obstacles
• Find the exit

We had to accomplish the Tasks automatically.

Test Environment

• ROS: Melodic
• Ubuntu: 18.04LTS
• Python: 3.6.9
• (Gazebo: 9.0.0)

Approached Code Structure

To execute the same, I created one python package(FinalProject_ws) which has one module (motion_plan). This module can be used in any catkin space if configured as per the tree below.

.
└── catkin_ws                       # Your simulation workspace
    ├── src                         # Cloned from this directory 
    │   ├── maze
    │   │   ├── launch
    │   │   |   ├── maze.launch 
    │   │   ├── world
    │   │   |   ├── maze.world      # Folder that contains maze 1's definitions
    │   │   |   └── maze2.world     # Folder that contains maze 2's definitions
    │   │   ├── CMakeLists.txt
    │   │   └── pakage.xml
    │   ├── motion_plan          
    │   │   ├── nodes
    │   │   |   ├── follow_wall.py  # Folder that contains motion planning for the robot
    │   │   ├── src
    │   │   |   └── ...
    │   │   ├── CMakeLists.txt
    │   │   └── pakage.xml
    │   └── CMakeLists.txt
    ├── devel                       # Folder created after compilation
    └── build                       # Folder created after compilation

Follow_wall.py:

This program consists of various fiunctions to check if the bot has detected a wall and based on the distance from obstacle on right side and left side, the program will either enter the algorithm for Right wall follower or the Left wall follower.

Instructions to run the code:(In PyCharm)

• Download the 'FinalProject_Nimbekar.zip' folder from Canvas and unzip it.

• Run the roscore command in terminal to start ros.

• Run the maze in terminal one:

roslaunch maze maze.launch

• Then run the Code in terminal two:

rosrun motion_plan follow_wall.py

• Manually stop the code once the maze is cleared.

Built With

• ROS - Set of software libraries and tools used to build the robot
• Gazebo - Tool used to simulation
• Python - Programming language

Author

Nupur Nimbekar