HURBA: SLAM tutorial II.

Dependencies:

• ROS Melodic
• Gazebo 9
• RViz
• Teleop twist keyboard
• Hector SLAM
• GMapping
• RTAB-Map
• AMCL
• Map server
• PGM Map Creator

Project build instrctions:

1. Clone this repo inside the src folder of a catkin workspace with the PGM Map Creator submodule: git clone --recurse-submodules https://github.com/hungarianrobot/Project-2-Mapping
2. Install libignition-math2-dev and protobuf-compiler to compile the map creator: sudo apt-get install libignition-math2-dev protobuf-compiler
3. Build workspace: catkin_make
4. Source environment: source devel/setup.bash

Test the simulation

1. Start the Gazebo simulation: roslaunch hurba_mapping world.launch
2. Start the teleop package: roslaunch hurba_mapping teleop.launch
3. Start RViz and open the basic_view.rviz configuration.
4. Drive the robot inside the simulated environment. Note: this time the robot is omnidirectional instead of the previous diff drive!

Save the ground truth map

1. Successfully build PGM Map Creator.
2. Copy the building.world Gazebo world file into src/pgm_map_creator/world/ folder.
3. Add <plugin filename="libcollision_map_creator.so" name="collision_map_creator"/> before the </world> tag.
4. Run Gazebo server with: gzserver src/pgm_map_creator/world/building.world.
5. Save the map with PGM Map Creator: roslaunch pgm_map_creator request_publisher.launch.
6. Copy the saved map.pgm to maps folder of the my_robot package and create a map.yaml with default values (see hurba_mapping/maps folder).

Hector SLAM

1. Start the Hector SLAM: roslaunch hurba_mapping hector_slam.launch
2. Start the teleop package: roslaunch hurba_mapping teleop.launch

GMapping

1. Start the GMapping package: roslaunch hurba_mapping gmapping_slam.launch
2. Start the teleop package: roslaunch hurba_mapping teleop.launch

RTAB-Map

1. Start the RTAB-Map package: roslaunch hurba_mapping rtab_map_slam.launch
2. Start the teleop package: roslaunch hurba_mapping teleop.launch

RTAB-Map Viz

Un-comment the rtabmapviz node in the rtab_map_slam.launch file. In the visualizer tool of RTAB-Map we can see the RGBD pointcloud of the environment:

Evaluating the RTAB-Map database

After the mapping is done we can evaluate the database with RTAB-Map's database viewer, that can be started with the following command:

rtabmap-databaseViewer ~/catkin_ws/src/Project-2-Mapping/hurba_mapping/maps/database/rtabmap.db

Once open, we will need to add some windows to get a better view of the relevant information, so:

• Say yes to using the database parameters
• View -> Constraint View
• View -> Graph View

We can check the number of loop closures during the mapping using the bottom left information:

(283, 0, 29, 0, 0, 0, 0, 0, 0) Links(N, NM, G, LS, LT, U, P, LM, GR)

Where G means the number of Global Loop Closures. The codes stand for the following: Neighbor, Neighbor Merged, Global Loop closure, Local loop closure by space, Local loop closure by time, User loop closure, and Prior link.

Project structure:

 tree -L 3

├── README.md
├── documentation
│   ├── database.png
│   ├── frames.png
│   ├── gazebo.png
│   ├── gmapping.png
│   ├── hector.png
│   ├── rosgraph.png
│   ├── rtabmap.png
│   ├── rtabmapviz.png
│   └── rviz.png
├── hurba_mapping
│   ├── CMakeLists.txt
│   ├── launch
│   │   ├── amcl_localization.launch
│   │   ├── gmapping_slam.launch
│   │   ├── hector_slam.launch
│   │   ├── robot_description.launch
│   │   ├── rtab_map_slam.launch
│   │   ├── teleop.launch
│   │   └── world.launch
│   ├── maps
│   │   ├── database
│   │   ├── map_hector.yaml
│   │   ├── map.pgm
│   │   └── map.yaml
│   ├── meshes
│   │   ├── chassis.dae
│   │   ├── chassis.SLDPRT
│   │   ├── chassis.STEP
│   │   ├── hokuyo.dae
│   │   ├── wheel.dae
│   │   ├── wheel.SLDPRT
│   │   └── wheel.STEP
│   ├── package.xml
│   ├── rviz
│   │   ├── amcl.rviz
│   │   ├── basic_view.rviz
│   │   ├── gmapping_slam.rviz
│   │   ├── hector_slam.rviz
│   │   └── rtab_slam.rviz
│   ├── urdf
│   │   ├── hurba_mecanum.gazebo
│   │   └── hurba_mecanum.xacro
│   └── worlds
│       ├── basic_world.world
│       ├── building.model
│       ├── building.world
│       └── empty.world
└── pgm_map_creator
    ├── CMakeLists.txt
    ├── launch
    │   └── request_publisher.launch
    ├── LICENSE
    ├── maps
    │   ├── example_map.pgm
    │   └── map.pgm
    ├── msgs
    │   ├── CMakeLists.txt
    │   └── collision_map_request.proto
    ├── package.xml
    ├── README.md
    ├── src
    │   ├── collision_map_creator.cc
    │   └── request_publisher.cc
    └── world
        ├── building.world
        ├── MyWorld.world
        └── udacity_mtv