Simultaneous Mapping And Localization using 2D LiDAR in ROS2

This project demonstrates 2D mapping and robot localization using LiDAR with slam_toolbox in ROS 2. The package enables autonomous mapping of environments and subsequent robot localization within those maps using a differential drive robot in Gazebo simulation. Check out the 2d mapping and localization here.

System Requirements

• Ubuntu: 24.04 LTS
• ROS 2: Jazzy Jalapa
• Gazebo: Harmonic

Usage

Prerequisites

Install required ROS 2 packages:

sudo apt install ros-jazzy-robot-state-publisher \
                 ros-jazzy-joint-state-publisher \
                 ros-jazzy-xacro \
                 ros-jazzy-teleop-twist-keyboard \
                 ros-jazzy-ros-gz-sim \
                 ros-jazzy-ros-gz-bridge \
                 ros-jazzy-slam-toolbox 

Installation & Setup

1. Create Workspace and Clone Repository

mkdir -p my_ws/src && cd my_ws/src
git clone https://github.com/yashikasharma0301/lidar_2d_mapping.git

2. Build the Workspace

cd ..
colcon build

3. Source the Workspace

source install/setup.bash

Running the Simulation

Phase 1: 2D Mapping

1. Launch Robot with LiDAR in Gazebo

ros2 launch lidar_2d_mapping gazebo_spawn.launch.py

2. Start SLAM Mapping

• In a new terminal:

cd my_ws
source install/setup.bash
ros2 launch lidar_2d_mapping slam_mapping.launch.py

• Wait for a minute and let it load

3. Create the Map

• In Gazebo, open the teleop plugin to control the robot

  

• Move the robot around the environment to generate a comprehensive map

• Monitor the mapping progress in RViz

  

4. Save the Map

• In RViz's "SlamToolboxPlugin" panel, enter the location where you want to save the map infront of the Serialize Map button :

  /home/YOUR_USERNAME/my_ws/src/lidar_2d_mapping/maps/map_serialize
  

  Replace YOUR_USERNAME with your actual username

• Click on Serialize Map to save the generated map

  

• Saving the map in Save Map allows you to use the map for external environments also whearas to use the map with slam_toolbox, you need to save the serialized map

• Close the mapping terminal once mapping is complete

Phase 2: Robot Localization

1. Configure Localization Parameters

gedit ~/my_ws/src/lidar_2d_mapping/params/mapper_params_localization.yaml

• Update the map_file_name parameter with your saved map location
• Optionally, set your preferred initial pose using the map_start_pose parameter
• Save and close the file
• Close all the terminals

2. Launch Localization

• In a new terminal rebuild the workspace and launch the gazebo world again:

cd my_ws
colcon build
source install/setup.bash
ros2 launch lidar_2d_mapping gazebo_spawn.launch.py

• In another terminal:

cd my_ws
source install/setup.bash
ros2 launch lidar_2d_mapping slam_localization.launch.py

3. Test Localization

• Use the Gazebo teleop plugin to move the robot

• Observe how the robot localizes itself within the previously created map

  

Credits & References

Robot Model: This project uses a URDF model adapted from the TortoiseBot example in the OSRF ROS Book. The original model has been modified for ROS 2 Jazzy and Gazebo Harmonic integration with LiDAR sensor capabilities.

Original Authors: Open Source Robotics Foundation (OSRF)