Requirements

• ROS 2 Humble
• Gazebo classic
• Rviz2

To run the simlation

Clone the following repository.

git clone https://github.com/HBRS-SDP/ss23-youbot_ros2_nav.git

Copy all folders to ros_ws/src folder

In a terminal, go to root of ros_ws and run the following command to build the packages

colcon build

Terminal 1

source ~/ros_ws/install/setup.bash 
ros2 launch youbot_gazebo start_world.launch.py

The top view of the gazebo world will look like the image shown below

Terminal 2

source ~/ros_ws/install/setup.bash
ros2 launch youbot_gazebo spawn_youbot_ros2.launch.xml

Terminal 3

source ~/ros_ws/install/setup.bash
ros2 run rviz2 rviz2

The rviz config file is present in the location ~/src/youbot_description/rviz/navigation.rviz

Terminal 4

source ~/ros_ws/install/setup.bash
ros2 run teleop_twist_keyboard teleop_twist_keyboard

From Terminal 4 you can control the robot.

For Mapping

Terminal 5

source ~/ros_ws/install/setup.bash
ros2 launch youbot_navigation online_async_launch.py

Terminal 6

Save the generated map using the following command

cd ~/ros_ws/src/youbot_navigation/maps
source ~/ros_ws/install/setup.bash
ros2 run nav2_map_server map_saver_cli -f {file_name}

Terminal 7

To publish the saved map for navigation

source ~/ros_ws/install/setup.bash
ros2 launch youbot_navigation youbot_nav2_bringup.launch.py

For Navigation on a saved map

Kill all the executing commands and close all the opened terminals. Then redo the steps from Terminal 1 and Terminal 2. Then run the following commands.

Terminal 3

source ~/ros_ws/install/setup.bash
ros2 launch youbot_navigation youbot_nav2_bringup.launch.py

Terminal 4

source ~/ros_ws/install/setup.bash
ros2 launch youbot_navigation localization.launch.py

After running the above command in terminal 4 use pose estimate in RVIZ to point the robot is the same direction and position where it is present in the gazebo world.

After localizing the youbot in rviz2, the resultant view is shown below

Terminal 5

source ~/ros_ws/install/setup.bash
ros2 launch youbot_navigation navigation.launch.py

Then in RVIZ window give a 2D Nav Goal and the robot will navigate to the goal.

To navigate the robot to the pre-defined goals (multi-goal navigation) in the map use below commands. The goal coordinates can be found in the .yaml file located at

• youbot_navigation/maps/navigation_goals_sim.yaml (for simulation)
• youbot_navigation/maps/navigation_goals.yaml (for real world)

Single Goal Navigation

Terminal 6

source ~/ros_ws/install/setup.bash
ros2 run youbot_navigation single_nav_goal.py

single-goal_rviz2.mp4

Multi Goal Navigation

Terminal 6

source ~/ros_ws/install/setup.bash
ros2 run youbot_navigation multi_nav_goal.py

multi-goal_rviz2.mp4