A* Search Algorithm

A* is one of the more popular algorithms used in path search, and as such is extensively used in robot trajectory planning/object avoidance. This project is intended to simulate the working of the A* algorithm and we make use of ROS to visualize the same. First, let us go over the dependencies.

Installing Dependencies

This package was built using Python 3.7 and C++ 14 on Ubuntu Kernel 20.04. Follow the instructions on this page to install ROS (Noetic) and this page to setup OpenCV for Ubuntu.

Running the Package

First, source your ROS environment using

source /opt/ros/noetic/setup.bash

Now, create and build a catkin workspace:

mkdir -p ~/catkin_ws/src
cd ~/catkin_ws/
catkin_make

Download the tbot package into the src folder. Open the terminal and enter the following command:

cd src
git clone git@github.com:latent-pixel/A-Star-Algorithm.git

Rename the package, just to make it easy going ahead:

mv A-Star-Algorithm astar

Build the package and launch turtlebot in a gazebo environment:

catkin build astar
roslaunch astar turtlebot3_prjct3.launch

Open another terminal window and use following commands to start the path planner. You can visualize the output on the gazebo window.

cd ~/catkin_ws/src/astar/src
chmod +x Navigator.py
python3 Navigator.py

Output

Upon running the package, you can visualize the A* algorithm in action,

Figure: Path planner output.

Video: Gazebo Visualization