SM23-AI-ROS-02

Download Turtlebot3 with SLAM packages with compatible ROS packages to create a map and save it while simultaneously make the robot model determine the environment based on its position.

SLAM Definition

Simultaneous localization and mapping (SLAM) is an algorithmic approach used in robotics to solve the computational problem of constructing or updating a map of an unknown environment while simultaneously keeping track of an agent's(robot) location within that environment.

The basic idea behind SLAM is to use sensor data from the robot's environment, such as laser range finders, cameras, or sonar sensors, to build a map of the environment and at the same time, use this map to estimate the robot's position. This is done by incrementally updating the map and the robot's position based on new sensor data as the robot moves through the environment.

Using a wide range of algorithms, computations, and other sensory data, SLAM software systems allow a robot or other vehicle—like a drone or self-driving car—to plot a course through an unfamiliar environment while simultaneously identifying its own location within that environment.

SLAM algorithms are widely used in robotics for applications such as autonomous vehicles, unmanned aerial vehicles, and mobile robots. They are essential for enabling robots to navigate and interact with their environments autonomously.

1- Install-ROS-on-Remote-PC:

After installing ubuntu and compatible ROS packges with ubuntu version downloaded.

Open the terminal and enter below commands in order only one time:

$ sudo apt update

$ sudo apt upgrade

$ wget https://raw.githubusercontent.com/ROBOTIS-GIT/robotis_tools/master/install_ros_noetic.sh

$ chmod 755 ./install_ros_noetic.sh

$ bash ./install_ros_noetic.sh

2- Install-Dependent-ROS-Packages:

This commands is for ROS melodic version "change the version name if you use deferent ROS version than melodic"

$ sudo apt-get install ros-melodic-joy ros-melodic-teleop-twist-joy \
  ros-melodic-teleop-twist-keyboard ros-melodic-laser-proc \
  ros-melodic-rgbd-launch ros-melodic-depthimage-to-laserscan \
  ros-melodic-rosserial-arduino ros-melodic-rosserial-python \
  ros-melodic-rosserial-server ros-melodic-rosserial-client \
  ros-melodic-rosserial-msgs ros-melodic-amcl ros-melodic-map-server \
  ros-melodic-move-base ros-melodic-urdf ros-melodic-xacro \
  ros-melodic-compressed-image-transport ros-melodic-rqt* \
  ros-melodic-gmapping ros-melodic-navigation ros-melodic-interactive-markers

3- Install-TurtleBot3-Packages:

Install TurtleBot3 via Debian Packages with compatible ROS version ( This commands is for ROS melodic version) "change the name if you use deferent version than melodic"

$ sudo apt install ros-melodic-dynamixel-sdk

$ sudo apt install ros-melodic-turtlebot3-msgs

$ sudo apt install ros-melodic-turtlebot3

4- Gazebo-Simulation:

Install Simulation Packages:

The TurtleBot3 Simulation Package requires turtlebot3 and turtlebot3_msgs packages as prerequisite. Without these prerequisite packages, the Simulation cannot be launched.

Before launching the simulation follow the PC Setup instructions below to install the required packages, if you already did not install required packages and dependent packages.

$ cd ~/catkin_ws/src/

$ git clone -b noetic-devel https://github.com/ROBOTIS-GIT/turtlebot3_simulations.git

$ cd ~/catkin_ws && catkin_make

5- Launch Simulation World:

Three simulation environments are prepared for TurtleBot3. Please select one of these environments to launch Gazebo.

"Make sure to completely terminate other Simulation world before launching a new world".

Use the proper keyword among burger , waffle , waffle_pi for the TURTLEBOT3_MODEL parameter before lunching TurtleBot3 world.

TurtleBot3 World lunch:

$ export TURTLEBOT3_MODEL=waffle

$ roslaunch turtlebot3_gazebo turtlebot3_world.launch

6- Run SLAM Simulation

Open a new terminal from Remote PC and run the SLAM node. Gmapping SLAM method is used by default.

Use the proper keyword among burger , waffle , waffle_pi for the TURTLEBOT3_MODEL parameter when you have lunched the TurtleBot3 World.

$ export TURTLEBOT3_MODEL=waffle

$ roslaunch turtlebot3_slam turtlebot3_slam.launch slam_methods:=gmapping

7- Run Teleoperation Node

Open a new terminal from Remote PC and run the teleoperation node from the Remote PC.

Use the proper keyword among burger , waffle , waffle_pi for the TURTLEBOT3_MODEL parameter when you have lunched the TurtleBot3 World.

$ export TURTLEBOT3_MODEL=waffle

$ roslaunch turtlebot3_teleop turtlebot3_teleop_key.launch

8- Saving the Map

When the map is created successfully, open a new terminal from Remote PC and save the map with the following command line.

$ rosrun map_server map_saver -f ~/map

Test the map and robotModel node movement

Testing the map with the robot model to determine the environment based on its own position.

How to move: in step seven "Run Teleoperation Node" terminal press the following to move the robotModel node ( forward= w, left= a, right= d, backward= x, force stop= s or space key)

Note: you can only move the robotModel node from the terminal used in step number seven (step 7: Run Teleoperation Node).

Resources

• turtlebot3 quick start guide: https://emanual.robotis.com/docs/en/platform/turtlebot3/quick-start/

• run slam and saving the map: https://emanual.robotis.com/docs/en/platform/turtlebot3/slam/

• hector_slam metapackage: http://wiki.ros.org/hector_slam

• cartographer: http://wiki.ros.org/cartographer

• gmapping package: http://wiki.ros.org/gmapping

• for more application information check this tutorial: https://youtu.be/JXnXnAXrYj8