Basic Turtlebot Navigation Guideline

To download the turtlebot simulator

sudo apt-get install ros-indigo-turtlebot-simulator


To load the turtlebot simulation

source /opt/ros/indigo/setup.bash
roslaunch turtlebot_gazebo turtlebot_world.launch


To launch the turtlebot

 roslaunch turtlebot_bringup minimal.launch

To move the turtlebot

roslaunch kobuki_keyop keyop.launch

***OR***

roslaunch turtlebot_teleop keyboard_teleop.launch
 
To download the turtlebot navigation

sudo apt-get install ros-indigo-turtlebot-navigation

This installs gmapping and amcl required for the navigation

To start map building

roslaunch turtlebot_gazebo gmapping_demo.launch


Use RViz to visualize the map building process

roslaunch turtlebot_rviz_launchers view_navigation.launch –screen


Finally, save the map to disk

rosrun map_server map_saver -f <your map name>


Navigating the Background

To be sure that all will run as expected, kill all you launched in the previous section and repeat all steps except the map building. Instead, type:

roslaunch turtlebot_gazebo amcl_demo.launch map_file:=<full path to your map YAML file>

Or if you prefer to use an already created map, just omit the map_file argument.

To use the map that you saved – first close everything. Then,

Load the turtlebot simulator again:

source /opt/ros/indigo/setup.bash
roslaunch turtlebot_gazebo turtlebot_world.launch
**Need to make sure that you ALWAYS source the bashrc file before launching the turtlebot gazebo simulator
Run the navigation demo app passing in your generated map file.

roslaunch turtlebot_navigation amcl_demo.launch map_file:=/tmp/my_map.yaml

**When launching the map, make sure you put the full path, i.e. /home/turtlebot/map1.yaml (this path should be after ‘=’)

Launch RViz to visualize the map building process

roslaunch turtlebot_rviz_launchers view_navigation.launch

Localize the Turtlebot

When starting up, the TurtleBot does not know where it is. To provide it its approximate location on the map:

  1. Click the “2D Pose Estimate” button

  2. Click on the map where the TurtleBot approximately is and drag in the direction the TurtleBot is pointing.

You will see a collection of arrows which are hypotheses of the position of the TurtleBot. The laser scan should line up approximately with the walls in the map. If things don’t line up well you can repeat the procedure.

Send a navigation goal

With the TurtleBot localized, it can then autonomously plan through the environment.

To send a goal:

  1. Click the “2D Nav Goal” button

  2. Click on the map where you want the TurtleBot to drive and drag in the direction the TurtleBot should be pointing at the end.

This can fail if the path or goal is blocked.

If you want to stop the robot before it reaches it’s goal, send it a goal at it’s current location.


On your Workstation

This assumes you have ROS on your workstation and ROS_MASTER_URI has been set to point to your turtlebot.

Launch rviz:

# Pre-Groovy

rosrun rviz rviz -d `rospack find turtlebot_navigation`/nav_rviz.vcg

# Groovy or later

roslaunch turtlebot_rviz_launchers view_navigation.launch –screen