Testing Explore-Lite

This page will provide a brief overview of my testing process for the explore-lite package.

Before you try to follow any of the instructions in this guide, make sure you have completed the steps in Software Setup. Otherwise, none of this will work, and you probably will get a few weird errors.

Overview

Using the multi-agent-mapping repository, it is very easy to test the explore-lite package, as well as other cooperative mapping packages. This guide will specifically focus on the setup I have configured for the explore-lite package, but feel free to use this as a starting point for other mapping packages. To help simplify matters, I have created an explore-lite launch file in the repository that automatically starts the nodes on the turtlebots. However, there a few disclaimers to note:

1. At the time of this publication, I have not yet been able to configure the local costmaps of the robots. While the global costmaps seem to function normally, the turtlebots are not able to access the /scan messages and build their own local costmaps. Therefore, the explore-lite package circumvents this issue by subscribing to /map messages instead of looking for a specific costmap.

2. Similarly, I have not yet been able to create a launch file that launches rviz with the correct configuration files. Therefore, my workaround is to use rosrun in two additional terminals to launch rviz before I launch the explore-lite nodes.

I plan on fixing these issues later as we continue our research into multi-agent SLAM.

Launching Explore-Lite

To launch explore-lite, you will need four terminals open on your system. Follow the below commands and explore-lite, along with rviz, should open on your machine. Make sure that you are in your repository's directory before running these commands.

# Terminal A
roslaunch multi-agent-mapping multi-agent-mapping.launch

# Terminal B
rosrun rviz rviz -d rviz/multi-agent-mapping.rviz

# Terminal C
rosrun rviz rviz -d rviz/multi-agent-mapping-2.rviz

# Terminal D
roslaunch multi-agent-mapping explore-lite.launch

With these commands ran, you should now see something similar to this on your computer screen. Additionally, the robots should begin moving and exploring more of the turtlebot house. On the left side of your screen, you will notice that the rviz window is subscribed to the individual maps. Meanwhile, on the right side of your screen, you will notice that the rviz window is subscribed to the global map that is being merged together. With this setup, you can visualize the progress that the robots are making on piecing together the global map. You can also begin to see where the overlapping scans are, which is useful for the map-mergingnode as it requires those to create a confident map.

Do not worry about the terminal, I moved it there manually.