Tutorial: Integrating Isaac Perceptor with Nav2 on a robot with the Nova Orin Developer Kit

This will guide you through the most important steps to using the Nova Orin Developer Kit with Nav2 on your own robot.

Benefits of integrating Isaac Perceptor with a Navigation Stack

By integrating Isaac Perceptor` with your navigation stack you can benefit from all advantages of camera-based perception:

Enhanced Obstacle Detection: Isaac Perceptor leverages camera-based local perception, allowing for the detection of low-lying obstacles that traditional 2D LiDARs may miss. This capability enhances the robot’s ability to navigate complex environments safely and efficiently.
Cost-Effective Solution: Cameras are significantly cheaper than 3D LiDARs, making Isaac Perceptor a cost-effective alternative without compromising on the quality of perception. This cost efficiency allows for broader deployment of advanced perception capabilities in various robotic applications.
Improved Semantic Understanding: Unlike LiDARs, cameras can provide rich semantic information about the environment. Isaac Perceptor can classify and identify specific objects, such as humans, and determine their positions. This advanced scene understanding enables more intelligent and context-aware navigation, crucial for applications in dynamic environments.
Future-Proofing: By incorporating camera-based perception, you are positioning your robotic system for future advancements in computer vision and AI. This approach ensures that your system remains adaptable and can take advantage of the latest innovations in perception technology.

Prerequisites

For this tutorial, you must have completed the Tutorial: Running Camera-based 3D Perception with Isaac Perceptor It is also assumed that you are familiar with Nav2 and that you are able to use it for lidar-based autonomous navigation on your robot. In this tutorial, we will guide you through essential steps to replace the lidar-based local perception with camera-based 3D perception from Isaac Perceptor.

Lastly, it is assumed that you have rigidly mounted the Nova Orin Developer Kit on your own robot and successfully completed extrinsic calibration.

Instructions

Install the required apt-packages into your environment

sudo apt-get update

sudo apt-get install -y ros-humble-nova-developer-kit-bringup

Add Isaac Perceptor to your existing Nav2 launch file by including the perceptor.launch.py of the nova_developer_kit_bringup package.

A rough example of the resulting launch filed is as follows. Please note that this launch file is incomplete and requires modifications and additions specific to your setup.

from launch import LaunchDescription
from launch.actions import IncludeLaunchDescription
from launch.launch_description_sources import PythonLaunchDescriptionSource
from launch_ros.substitutions import FindPackageShare

def generate_launch_description():
    # Create the LaunchDescription object.
    launch_description = LaunchDescription()

    # Include the perceptor.launch.py from the nova_developer_kit_bringup package
    perceptor_launch = IncludeLaunchDescription(
        PythonLaunchDescriptionSource([
            FindPackageShare('nova_developer_kit_bringup'),
            '/launch/perceptor.launch.py'
        ]),
        launch_arguments={'stereo_camera_configuration': 'front_left_right_configuration'}.items()
    )
    ld.add_action(perceptor_launch)

    # Add any other ROS nodes you might need here.
    ld.add_action(...)

    # Include the Nav2 lidar localization:
    localization_launch = IncludeLaunchDescription(
        PythonLaunchDescriptionSource([
            FindPackageShare('nav2_bringup'),
            'launch/localization_launch.py',
        ]),
        # Make sure to replace the parameters below with valid paths.
        launch_arguments={
            'map': 'path/to/map/yaml',
            'params_file': 'path/to/nav2/parameters'
        }.items(),
    )
    ld.add_action(localization_launch)

    # Include the Nav2 launch file:
    nav2_launch = IncludeLaunchDescription(
        PythonLaunchDescriptionSource([
            FindPackageShare('nav2_bringup'),
            'launch/navigation_launch.py',
        ]),
        # Make sure to replace the params_file below with a valid path.
        launch_arguments={'params_file': 'path/to/nav2/parameters'}.items(),
    )
    ld.add_action(nav2_launch)

    return launch_description

Note

You can customize the sensor configuration of Isaac Perceptor by providing the stereo_camera_configuration launch argument. For a detailed description of all available configurations refer to Tutorial: Stereo Camera Configurations for Isaac Perceptor.

Note

If you are using node composition please make sure to use separate ROS 2 component containers for the Perceptor nodes and the Nav2 nodes. The Perceptor nodes have to be in a component_container_mt container, whereas the Nav2 nodes cannot be in a component_container_mt node due to a race-condition in ROS 2 humble’s action server.

Update your Nav2 parameters to include Isaac nvblox as a layer in the local costmap. We assume you have the Nav2 parameters stored in a YAML file. You will have to add the definition of the Isaac nvblox costmap layer to the parameters of your local costmap:

local_costmap:
    nvblox_layer:
    plugin: "nvblox::nav2::NvbloxCostmapLayer"
    enabled: True
    nav2_costmap_global_frame: odom # must match with global_frame of local_costmap
    nvblox_map_slice_topic: "/nvblox_node/static_map_slice"
    convert_to_binary_costmap: True

Additionally then also include the new nvblox_layer in the plugins parameter of the local costmap next to any other layers you may already have:

plugins: ['nvblox_layer', '<any-additional-layers-you-may-have>']

In summary, the parameters of your local costmap should now look something like this (you will most likely have additional costmap plugins and different parameters):

local_costmap:
    local_costmap:
        ros__parameters:
            footprint_padding: 0.03
            update_frequency: 5.0
            publish_frequency: 2.0
            global_frame: odom
            robot_base_frame: base_link
            rolling_window: true
            width: 5
            height: 5
            resolution: 0.05
            transform_tolerance: 0.3
            footprint: "[ [0.14, 0.25], [0.14, -0.25], [-0.607, -0.25], [-0.607, 0.25] ]"
            mark_threshold: 2
            always_send_full_costmap: True
            plugins: ['nvblox_layer', 'inflation_layer']
            inflation_layer:
                plugin: "nav2_costmap_2d::InflationLayer"
                enabled: True
                cost_scaling_factor: 10.0
                inflation_radius: 0.8
            nvblox_layer:
                plugin: "nvblox::nav2::NvbloxCostmapLayer"
                enabled: True
                nav2_costmap_global_frame: odom # must match with global_frame of local_costmap
                nvblox_map_slice_topic: "/nvblox_node/static_map_slice"
                convert_to_binary_costmap: True

Integration Reference Example

For a complete example of how to integrate Isaac Perceptor with Nav2 we recommend taking a look at the navigation launch file for the Nova Carter robot.