nav2_bringup

The nav2_bringup package is an example bringup system for navigation2 applications.

Notes: (December 2018, Crystal Release) * We recommend doing this on a Ubuntu 18.04 installation. We’re currently having build issues on 16.04. (see https://github.com/ros-planning/navigation2/issues/353) * This stack and ROS2 are still in heavy development and there are some bugs and stability issues being worked on, so please do not try this on a robot without taking heavy safety precautions. THE ROBOT MAY CRASH! * It is recommended to start with simulation using Gazebo before proceeding to run on a physical robot

Install and build our code by following this guide: https://github.com/ros-planning/navigation2/blob/master/doc/BUILD.md

Launch Navigation2 in simulation with Gazebo (first time users)

Pre-requisites:

• Gazebo installed on the system
• gazebo_ros_pkgs for ROS2 installed on the system
• A Gazebo world for simulating the robot (see Gazebo tutorials)
• A map of that world saved to a map.pgm and map.yaml (see ROS Navigation tutorials)

Terminal 1: Launch Gazebo and Rviz2

Example: See turtlebot3_gazebo models for details

export GAZEBO_MODEL_PATH=$GAZEBO_MODEL_PATH:<full/path/to/my_robot/models>
ros2 launch nav2_bringup gazebo_rviz2_launch.py world:=<full/path/to/gazebo.world>

Terminal 2: Launch your robot specific transforms

Example: See turtlebot3_gazebo for details

ros2 launch turtlebot3_bringup turtlebot3_robot.launch.py

Terminal 3: Launch map_server and AMCL

# Set the tf publisher node to use simulation time or AMCL won't get the transforms correctly
ros2 param set /robot_state_publisher use_sim_time True
# Launch map_server and AMCL, set map_type as "occupancy" by default.
ros2 launch nav2_bringup nav2_bringup_1st_launch.py map:=<full/path/to/map.yaml> map_type:=occupancy use_sim_time:=True

In RVIZ: * Make sure all transforms from odom are present. (odom->base_link->base_scan) * Localize the robot using “2D Pose Estimate” button.

Terminal 4:

Run the rest of the Navigation2 bringup

ros2 launch nav2_bringup nav2_bringup_2nd_launch.py use_sim_time:=True

Terminal 5:

Set the World Model and the two costmap nodes to use simulation time

ros2 param set /world_model use_sim_time True
ros2 param set /global_costmap/global_costmap use_sim_time True
ros2 param set /local_costmap/local_costmap use_sim_time True

Notes: * Setting use_sim_time has to be done dynamically after the nodes are up due to this bug:https://github.com/ros2/rclcpp/issues/595 * Sim time needs to be set in every namespace individually. * Sometimes setting use_sim_time a second time is required for all the nodes to get updated * IF you continue to see WARN messages like the ones below, retry setting the use_sim_time parameter

[WARN] [world_model]: Costmap2DROS transform timeout. Current time: 1543616767.1026, global_pose stamp: 758.8040, tolerance: 0.3000, difference: 1543616008.2986
[WARN] [FollowPathNode]: Costmap2DROS transform timeout. Current time: 1543616767.2787, global_pose stamp: 759.0040, tolerance: 0.3000, difference: 1543616008.2747

In RVIZ: * Add "map" to subscribe topic "/map" * Add "RobotModel", set "Description Source" with "File", set "Description File" with the name of the urdf file for your robot (example: turtlebot3_burger.urdf)" * Localize the robot using “2D Pose Estimate” button. * Send the robot a goal using “2D Nav Goal” button.

Launch Navigation2 on a Robot (first time users)

Pre-requisites: * Run SLAM or Cartographer with tele-op to drive the robot and generate a map of an area for testing first. The directions below assume this has already been done. If not, it can be done in ROS1 before beginning to install our code. * Publish all the transforms from your robot from base_link to base_scan

Launch the code using this launch file and your map.yaml:

ros2 launch nav2_bringup nav2_bringup_1st_launch.py map:=<full/path/to/map.yaml> map_type:=occupancy

In another terminal, run RVIZ:

ros2 run rviz2 rviz2

In RVIZ: * Make sure all transforms from odom are present. (odom->base_link->base_scan) * Localize the robot using “2D Pose Estimate” button.

Run the rest of the Navigation2 bringup

ros2 launch nav2_bringup nav2_bringup_2nd_launch.py

In RVIZ: * Localize the robot using “2D Pose Estimate” button. * Send the robot a goal using “2D Nav Goal” button.

Advanced 1-step Launch for experienced users

Pre-requisites: * You've completed bringup of your robot successfully following the 2-step process above * You know your transforms are being published correctly and AMCL can localize

Follow directions above except * Instead of running the nav2_bringup_1st_launch.py then the nav2_bringup_2nd_launch.py * You can do it in one step like this:

ros2 launch nav2_bringup nav2_bringup_launch.py map:=<full/path/to/map.yaml>

If running in simulation:

ros2 launch nav2_bringup nav2_bringup_launch.py map:=<full/path/to/map.yaml> use_sim_time:=True
ros2 param set /world_model use_sim_time True; ros2 param set /global_costmap/global_costmap use_sim_time True; ros2 param set /local_costmap/local_costmap use_sim_time True

Future Work

• adding configuration files for the example bringup
• a more complete map for system level testing