Isaac ROS Visual Global Localization

Source code on GitHub.

Overview

This package includes the ROS node and launch files for visual global localization. It takes the global localization map along with raw or rectified stereo images as inputs and outputs the global pose. The package supports both single and multiple stereo image inputs.

Quickstart

Set Up Development Environment

1. Set up your development environment by following the instructions in getting started.

2. Clone isaac_ros_common under ${ISAAC_ROS_WS}/src.

   cd ${ISAAC_ROS_WS}/src && \
      git clone -b release-3.2 https://github.com/NVIDIA-ISAAC-ROS/isaac_ros_common.git isaac_ros_common
   

3. (Optional) Install dependencies for any sensors you want to use by following the sensor-specific guides.

   Note

   We strongly recommend installing all sensor dependencies before starting any quickstarts. Some sensor dependencies require restarting the Isaac ROS Dev container during installation, which will interrupt the quickstart process.

For Nova Carter Setup follow: Nova Carter Getting Started.

For x86 Rosbag Replay Testing follow:

1. Add your data volume to the Docker container by adding the following line to the .isaac_ros_dev-dockerargs file under scripts, for example:

   echo -e '-v /mnt/nova_ssd/recordings:/mnt/nova_ssd/recordings' > ${ISAAC_ROS_WS}/src/isaac_ros_common/scripts/.isaac_ros_dev-dockerargs
   

2. Add the extra image layer that is needed for mapping and localization. If you are not setting up the Nova Carter robot, remove nova_carter from CONFIG_IMAGE_KEY.

   echo -e "CONFIG_IMAGE_KEY=ros2_humble\nCONFIG_DOCKER_SEARCH_DIRS=(../docker)" > ${ISAAC_ROS_WS}/src/isaac_ros_common/scripts/.isaac_ros_common-config
   

3. Launch the Docker container using the run_dev.sh script:

   cd ${ISAAC_ROS_WS}/src/isaac_ros_common && \
   ./scripts/run_dev.sh
   

Install or Build Isaac ROS Visual Global Localization

Install Binary PackageBuild from Source

1. Install the prebuilt Debian package in the container:

   sudo apt-get update
   

   sudo apt-get install -y ros-humble-isaac-ros-visual-global-localization
   

Localization with Rosbag Replay

We provide an end-to-end ROS launch file for replaying a rosbag and running global localization. It continuously run global localization on incoming frames, even after a localization pose has already been computed. It also activates the 3D Lidar to create a point cloud overlay on the occupancy map using the result poses.

1. Create a map by following Tutorial with Map Creation.

2. Record a localization rosbag with isaac_ros_nova_recorder Quickstart. Please keep the localization trajectory within 1m from the map trajectory’s coverage.

3. Launch container and run the following command to replay the localization rosbag and localize the robot:

   ros2 launch isaac_ros_visual_global_localization run_cuvgl_rosbag_replay.launch.py \
      rosbag_path:=$ROS_BAG_PATH \
      camera_names:='front_back_left_right' \
      vgl_map_dir:=${MAP_DIR}/cuvgl_map \
      occupancy_map_yaml_file:=${MAP_DIR}/occupancy_map.yaml
   

Note

For live testing, please see ISAAC Perceptor Localization

Visualize Results

Visualize the /map, /front_3d_lidar/lidar_points_filtered, and /visual_localization/pose topics in RViz or Foxglove. The alignment between the point cloud and the occupancy map indicates the accuracy of the result pose, which is used to transform the point cloud into the occupancy map frame. The axes shows the localization pose, with the red axes pointing in the the robot’s forward direction.

Try More Examples

To continue your exploration, check out the following suggested examples:

• Tutorial with Map Creation
• Tutorial with Visual Global Localization

Coordinate Frames

This section describes the coordinate frames that are involved in the VisualGlobalLocalizationNode. The frames discussed below are oriented as follows:

1. base_frame: The base frame of the robot or camera rig. It is assumed that all cameras are rigidly mounted to this frame, such that the transforms between the base_frame and the camera_optical_frames can assumed to be static. The estimated odometry and SLAM pose will represent the pose of this frame.

2. map_frame: The frame corresponding to the origin of the map that cuVGL creates or localizes in. The SLAM pose reported by cuVGL corresponds with the transform map_frame -> base_frame.

3. camera_optical_frames: The frames corresponding to the optical center of every camera. The frame is expected to lie at the center of the camera lens and oriented with the z-axis pointing in the view direction and the y-axis pointing to the floor.

Troubleshooting

Isaac ROS Troubleshooting

For solutions to problems with Isaac ROS, please check here.

Troubleshooting Suggestions

1. If localization frequently fails to return a pose, consider relaxing the rejection criteria, allowing it to return less confident results, by setting: vgl_localization_precision_level:=0.

2. To print more debug messages from the localization node, use launch parameters: vgl_verbose_logging:=True vgl_init_glog:=True vgl_glog_v:=1.

API

Usage

ros2 launch isaac_ros_mapping_and_localization isaac_ros_visual_global_localization_node.launch.py

ROS Parameters

ROS Parameter	Type	Default	Description
Functional Parameters
num_cameras	int	2	Number of cameras used. Set to 2 for single stereo camera.
stereo_localizer_cam_ids	std::string	0,1	Camera ids for stereo camera pairs, in the form of “stereo0_left_camera_id,stereo0_right_camera_id,stereo1_left_camera_id…”.
image_sync_match_threshold_ms	double	5.0	Maximum duration between image timestamps to still consider them synced.
enable_rectify_images	bool	false	If enabled, will do rectification for the incoming images.
enable_continuous_localization	bool	true	Whether or not to continue triggering localization after a localization pose is successfully computed.
use_initial_guess	bool	false	If use_initial_guess is true, the localizer will do cuSFM-based localization. If it is false, the localizer will do global localization.
map_dir	std::string	""	Required, the directory of cuVGL map files.
config_dir	std::string	""	Required, the directory of config files, which should include keypoint_creation_config.pb.txt and localizer_config.pb.txt.
model_dir	std::string	""	The directory of model file. This value can be set in config file.
input_image_topic_name	std::string	visual_localization/image	The topic name of the input image.
input_camera_info_topic_name	std::string	visual_localization/camera_info	The topic name of the input camera info.
localization_precision_level	int	2	The localization precision level: 0 for lowest precision, returning more poses; 1 for medium precision; 2 for highest precision, returning fewer poses.
Frame Parameters
map_frame	std::string	vmap	The frame name associated with the map origin.
base_frame	std::string	base_link	The frame name associated with the base of the robot or camera rig.
camera_optical_frames	std::vector<std::string>	[]	The frame names associated with the cameras’ optical frames. Using ROS optical frame conventions, i.e. z-axis front, y-axis down. If not specified will use the frames from the camera info messages.
Message Parameters
image_buffer_size	int	100	Buffer size used by the image synchronizer.
image_qos_profile	std::string	DEFAULT	QoS profile for the image subscribers.
Output Parameters
publish_map_to_base_tf	bool	true	Enable tf broadcaster for map_frame -> odom_frame transform.
invert_map_to_base_tf	bool	false	Invert the map_frame -> odom_frame transform before broadcasting to the tf tree.
Debug/Visualization Parameters
debug_dir	std::string	false	If it is set, will generate debug images to this folder.
debug_map_raw_dir	std::string	""	Optional, the directory that saves the raw images of the map frames.
publish_rectified_images	bool	false	Optional, if to publish the rectified images. This flag is used only when enable_rectify_image is true.
verbose_logging	bool	flase	Optional, if to print more verbose ROS logs.
init_glog	bool	flase	Optional, if to initialize glog. Note that glog can be initialized only once per process, otherwise it raises error.
glog_v	int	0	Optional, the verbose level for glog.

ROS Topics Subscribed

ROS Topic	Interface	Description
visual_localization/image_{i}	sensor_msgs/Image	Image from the i-th camera in grayscale (i is in range [0, num_cameras-1]).
visual_localization/camera_info_{i}	sensor_msgs/CameraInfo	Camera info from the i-th camera (i is in range [0, num_cameras-1]).
visual_localization/trigger_localization	geometry_msgs/PoseWithCovarianceStamped	Pose used as tick for localizing in an existing map. Every received message will trigger a localization.

ROS Topics Published

ROS Topic	Interface	Description
visual_localization/pose	geometry_msgs/PoseWithCovarianceStamped	Current pose with covariance of the base_frame.
visual_localization/debug_image	sensor_msgs/Image	Image for debugging.
visual_localization/camera_{i}/image_rect	sensor_msgs/Image	Rectified images from visual localization node, published only when enable_rectify_images and publish_rectified_images are set true.
visual_localization/camera_{i}/camera_info_rect	sensor_msgs/CameraInfo	Camera info for the rectified images, published only when enable_rectify_images and publish_rectified_images are set true.
/diagnostics	diagnostic_msgs/DiagnosticArray	Diagnostic message. Similar to status topic but in a different format.

ROS Services Advertised

ROS Service	Interface	Description
visual_localization/trigger_localization	std_srvs::srv::Trigger	A service to trigger localization the node.