.. _isaac_sim_app_tutorial_ros_multi_navigation: ============================== Multiple Robot ROS Navigation ============================== Learning Objectives ======================= In this ROS sample, we are demonstrating |isaac-sim| integrated with the ROS Navigation stack to perform simultaneous multiple robot navigation. Getting Started =========================== **Prerequisite** - The ROS Navigation stack is required to run this sample. Install the ROS Navigation stack: .. code-block:: bash sudo apt-get install ros-$ROS_DISTRO-navigation - This tutorial requires ``carter_2dnav``, ``carter_description``, and ``isaac_ros_navigation_goal``. The packages are located under the directory ``/src/navigation/``. They contain the required launch file, navigation parameters, and robot model. Complete :ref:`isaac_sim_app_install_ros`, make sure ROS environment is setup correctly and those packages are inside your ``ROS_PACKAGE_PATH``. - Completed :ref:`isaac_sim_app_tutorial_ros_navigation` tutorial for a single robot. - ``roscore`` is running before running |isaac-sim|. Hospital Environment Setup: ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ In this scenario, an occupancy map is required. For this sample, we are generating the map of both the Hospital and Office environments using the :ref:`Occupancy Map Generator extension ` within |isaac-sim|. 1. In a new stage, go to `Create -> Isaac -> Environments -> Hospital`. 2. At the upper left corner of the viewport, click on `Perspective`. Select `Top` from the dropdown menu. Select the `Hospital` prim and press `F` to zoom to selection. Adjust the camera view as needed. 3. Next, go to `Isaac Utils -> Occupancy Map`. 4. In the Occupancy Map extension, ensure the Origin is set to ``X: 0.0, Y: 0.0, Z: 0.0``. For the lower bound, set ``Z: 0.1``. For the Upper Bound, set ``Z: 0.62``. Keep in mind, the upper bound Z distance has been set to 0.62 meters to match the vertical distance of the lidar onboard Carter with respect to the ground. 5. Select the `Hospital` prim in the stage. In the Occupancy Map extension, click on ``BOUND SELECTION``. The bounds of the occupancy map should be updated to incorporate the selected `Hospital` prim. The map parameters should now look similar to the following image: .. figure:: /content/images/isaac_sample_ros_multiple_robot_nav_1.png :align: center :width: 600 :alt: Occupancy Map Properties UI Window for Hospital Environment A perimeter will be generated and it should resemble this image (Top View): .. figure:: /content/images/isaac_sample_ros_multiple_robot_nav_2.png :align: center :width: 600 :alt: Top View of Hospital with Occupancy Map Office Environment Setup: ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 1. In a new stage, go to `Create -> Isaac -> Environments -> Office`. 2. At the upper left corner of the viewport, click on `Perspective`. Select `Top` from the dropdown menu. Select the `Office` prim and press `F` to zoom to selection. Adjust the camera view as needed. 3. Next, go to `Isaac Utils -> Occupancy Map`. In the Occupancy Map extension, set the map parameters to be similar to the following image: .. figure:: /content/images/isaac_sample_ros_multiple_robot_nav_3.png :align: center :width: 600 :alt: Occupancy Map Properties UI Window for Office Environment Keep in mind, the upper bound Z distance has been set to 0.62 meters to match the vertical distance of the lidar onboard Carter with respect to the ground. A perimeter will be generated and it should resemble this image (Top View): .. figure:: /content/images/isaac_sample_ros_multiple_robot_nav_4.jpg :align: center :width: 600 :alt: Top View of Office with Occupancy Map | | 4. Once the setup for either environments is complete, click on ``CALCULATE`` followed by ``VISUALIZE IMAGE``. A Visualization popup will appear. 5. For `Rotate Image`, select 180 degrees and for Coordinate Type select ``ROS Occupancy Map Parameters File (YAML)``. Click ``RE-GENERATE IMAGE``. Occupancy map parameters formatted to YAML will appear in the field below. Change the image name to your preference. Copy the full text. 6. Create a YAML file for the occupancy map parameters called ``carter_hospital_navigation.yaml`` and place it in the map directory which is located in the sample ``carter_2dnav`` ROS package (``carter_2dnav/map/carter_hospital_navigation.yaml``). 7. Insert the previously copied text in the ``carter_hospital_navigation.yaml`` file. .. note:: For the office environment, follow the previous steps however create a YAML file called ``carter_office_navigation.yaml`` instead. 8. Back in the visualization tab in |isaac-sim|, click ``Save Image``. Set the same image name as in the map parameters and choose to save in the same directory as the map parameters file. - The final saved image of the Hospital environment will look like the following: .. figure:: /content/images/isaac_sample_ros_nav_hospital_map.png :align: center :width: 500 :alt: Sample Occupancy Map generated from hospital stage - The final saved image of the Office environment will look like the following: .. figure:: /content/images/isaac_sample_ros_nav_office_map.png :align: center :width: 500 :alt: Sample Occupancy Map generated from office stage An occupancy map is now ready to be used with Multiple Robot ROS Navigation! Multiple Robot ROS Navigation Setup ====================================== Open hospital scene by going to `Isaac Examples -> ROS -> Multi Robot Navigation -> Hospital Scene`. For operating multiple robots in the same environment, namespaces are utilized. This modifies the rostopic and rosnode names as well as frame ID's for different ROS packages, allowing for multiple instances of the same ROS node to run simultaneously. To publish and receive ROS messages under namespaces, the ``node_namespace`` |omnigraph_short| node found in each of the ``ActionGraph`` and ``ROS_Cameras`` graphs under ``Carter_ROS`` has been set to the corresponding robot names. The ``multiple_robot_carter_navigation.launch`` file found in the sample ``carter_2dnav`` ROS package is also configured with the same robot namespaces. Running Multiple Robot ROS Navigation ====================================== 1. Load scenario: - For hospital environment, go to `Isaac Examples -> ROS -> Multi Robot Navigation -> Hospital Scene`. - For the Office scenario, go to `Isaac Examples -> ROS -> Multi Robot Navigation -> Office Scene`. 2. Click on ``Play`` to begin simulation. 3. In a new terminal, run the ROS launch file and set the `env_name` parameter to either `hospital` or `office` to begin Multiple Robot Navigation with the desired environment. .. code-block:: bash roslaunch carter_2dnav multiple_robot_carter_navigation.launch env_name:=hospital OR .. code-block:: bash roslaunch carter_2dnav multiple_robot_carter_navigation.launch env_name:=office RViz will open and begin loading urdf models of three NVIDIA Carter robots, the global occupancy map, as well as the local costmaps of each robot. 4. To verify that all of the transforms are broadcasting, run the following command in a new terminal to visualize the ROS TF frame tree: .. code-block:: bash rosrun rqt_tf_tree rqt_tf_tree The generated graph should look similar to the one shown below. .. figure:: /content/images/isaac_sample_ros_multiple_robot_nav_5.jpg :align: center :width: 2000 :alt: ROS TF frame tree Since the positions of each robot is defined in ``multiple_robot_carter_navigation.launch``, the robots should already be properly localized. 5. In RViz, click on `Tool Properties -> 2D Nav Goal -> Topic`, and set the topic namespace to either ``/carter1``, ``/carter2`` or ``/carter3`` corresponding to specific robot you wish to set the navigation goal for. 6. Next, click on the ``2D Nav Goal`` button and then click and drag at the desired location point in the map. The ROS Navigation stack will now generate a trajectory and the specified robot will start moving towards its destination! Repeat this process for every other robot. .. raw:: html
.. note:: The ROS Image publishers are disabled by default to improve performance. To start publishing images, open the ``ROS_Cameras`` graph found under each of the Carter_ROS prims and enable the branch nodes as desired. To learn more see :ref:`isaac_sim_app_carter_ros_omnigraph`. Running in python directly ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Alternatively, to load this sample environment from python directly, follow the steps outlined :ref:`here`. .. _isaac_sim_app_tutorial_ros_multi_nav_goals: Sending Goals Programmatically for Multiple Robots ==================================================== The ``isaac_ros_navigation_goal`` ROS package can be used to set goal poses for multiple robots simultaneously. Refer to :ref:`isaac_sim_app_tutorial_ros_nav_goals` to learn about the configurations and parameters of this package. To send navigation goals to multiple robots simultaneously, setting up ROS namespaces are required. In a launch file, we can easily setup namespaces by wrapping the required params and node with the ```` tag. Refer to this page to learn more about `the group tag `_. #. Set up the namespace "carter1" by adding group tags around the parameters and node defined in ``isaac_ros_navigation_goal/launch/isaac_ros_navigation_goal.launch``. The resulting launch file should resemble the following: .. code-block:: xml :emphasize-lines: 2,11 [0, 0, 0, 0, 0, 1, 0] Remember to update the map yaml file path and the initial pose of `carter1` for either the hospital or office scenario. .. note:: If goal generator type is set to ``RandomGoalGenerator`` then a goal text file will not be used. #. Duplicate the `carter1` group configuration and modify them for `carter2` and `carter3` namespaces. The map yaml file path can be identical in all three groups. Make sure to update the initial poses of `carter2` and `carter3`. .. note:: If goal generator type is set to ``GoalReader`` then a separate goal text file must be created for each namespace group. #. To run the newly modified launch file, use the following command: .. code-block:: bash roslaunch isaac_ros_navigation_goal isaac_ros_navigation_goal.launch .. note:: Due to the higher complexity of the hospital or office scenes it may take up to 5 minutes for initial goals to be automatically set. Summary ======== In this tutorial, we covered running multiple robots with the ROS navigation stack. Next Steps ^^^^^^^^^^^^^^^^^^^^^^ Go to the next tutorial :ref:`isaac_sim_app_tutorial_ros_manipulation` to learn how to move a manipulator using direct joint control. Further Learning ^^^^^^^^^^^^^^^^^^^^^^ - To learn more about ROS Navigation refer to the ROS website: ``_ - ROS name conventions refer to the website: ``_. - Standalone python scripting version: :ref:`isaac_sim_app_tutorial_ros_python_multi_navigation`. With this approach you have the ability to manually control the timestep and rate at which ROS components are published.