Reactive wall following robot with laser scanner sensor

This project implements a wall-following algorithm in python for an autonomous mobile 2 wheeled robot with a laser scanner sensor using the Robot Operating System (ROS) libraries, Gazebo as simulator and Python as programming language. The proposed wall-following algorithm makes a robot wander at random until a wall is found, then follows the wall - through an implemented proportional control to keep a constant distance from it - in the outside and inside of a “V" and "W" shaped wall, respectively.

Getting Started

These instructions will get you a copy of the project up and running on your local machine for development and testing purposes.

Test Environment

• ROS: Indigo
• Ubuntu: 14.04LTS
• Python: 2.7.6
• (Gazebo: 7.12.0)

Project structure

Catkin Workspace Folder

.
├── catkin_ws               # Catkin Workspace
│   ├── src                 # Source files 
│   │   ├── two-wheeled-robot-motion-planning
│   │   │   ├── scripts     # Folder that contains the follow wall scripts
│   │   │   └── ...
│   │   └── ...
│   ├── devel               # Folder created after compilation
│   │   ├── setup.bash      # Shell Script to add environment variables to your path
│   │   └── ...             # etc.
│   └── build               # Compiled files
└── simulation_ws

Simulation Workspace Folder

.
└── simulation_ws           # Simulation Workspace
    ├── src                 # Source files 
    │   ├── two-wheeled-robot-simulation
    │   │   ├── m2wr_description    # Folder that contains the robot definition
    │   │   ├── my_worlds           # Folder that contains world's definitions
    │   │   └── ...
    │   └── ...
    ├── devel               # Folder created after compilation
    │   ├── setup.bash      # Shell Script to add environment variables to your path
    │   └── ...             # etc.
    └── build               # Compiled files

Setup

After clone the project navigate to the project folder

cd ros-wall-follower-2-wheeled-robot-master

Navigate to Catkin Workspace and run catkin_make

cd catkin_ws
catkin_make

Return to the project folder

cd ..

Navigate to Simulation Workspace and run catkin_make

cd simulation_ws
catkin_make

Running the tests

To run the tests it will be necessary to use 3 different terminals. Follow the steps starting at project root folder.

First Terminal

Do not close this terminal

1. Run the command to setup the environments variables on this terminal:

source simulation_ws/devel/setup.bash

2. Choose and launch the World that you want to simulate:

roslaunch my_worlds V_world.launch

or

roslaunch my_worlds W_world.launch

Second Terminal

1. Run the command to setup the environments variables on this terminal:

source simulation_ws/devel/setup.bash

2. Spawn the Mobile 2 Wheeled Robot on the World:

roslaunch m2wr_description spawn.launch y:=1

Third Terminal

Do not close this terminal

1. Run the command to setup the environments variables on this terminal:

source catkin_ws/devel/setup.bash

2. Run the wall-following script:

rosrun two-wheeled-robot-motion-planning follow_wall.py

Built With

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

Authors

• Ana Rafael
• Cássio Santos