text_nav_bridge

Text-command-driven robot navigation for ROS 2. Reads text landmarks generated by TextMap (Phase 1) and converts user text commands into Nav2 NavigateToPose actions.

Dependencies

• ROS 2 Humble
• navigation2
• rtabmap_ros
• textmap (provides shared text_similarity.hpp)
• yaml-cpp, tf2, rclcpp_action

sudo apt install ros-humble-navigation2 ros-humble-nav2-bringup ros-humble-rtabmap-ros

Build

cd ~/ros2_ws
colcon build --packages-select text_nav_bridge
source install/setup.bash

Usage (Phase 2: Navigation)

Requires Phase 1 outputs: rtabmap.db (map) and landmarks.yaml (text landmarks).

1. Launch navigation stack

ros2 launch text_nav_bridge text_nav.launch.py landmark_file:=/path/to/landmarks.yaml

2. Play rosbag or run real camera

# Rosbag
ros2 bag play <your_bagfile> --clock

# Or real camera
ros2 launch rtabmap_ros realsense_infra_for_record.launch.py

This launches:

• Static TF (RealSense D435i)
• IMU filter
• RGBD odometry
• RTAB-Map localization mode (uses existing rtabmap.db)
• Nav2 navigation stack
• text_nav_bridge node
• RViz

3. Send a text command

ros2 topic pub --once /text_nav/command std_msgs/msg/String "data: 'restroom'"

The node will:

1. Find the best matching landmark from landmarks.yaml
2. Compute a goal point approach_distance meters in front of the landmark
3. Send a NavigateToPose goal to Nav2

4. Monitor status

ros2 topic echo /text_nav/status

data: "NAVIGATING: heading to 'restroom'"
data: "NAVIGATING: distance_remaining=2.31m"
data: "SUCCESS: Navigation completed"

Launch Arguments

Argument	Default	Description
landmark_file	(required)	Path to landmarks.yaml
use_sim_time	true	Use simulation time (true for rosbag)

Node Parameters

Parameter	Default	Description
landmark_file	(required)	Path to landmarks.yaml
match_threshold	0.5	Text similarity threshold (0~1)
approach_distance	1.5	Stop this many meters before the landmark
robot_frame	camera_link	Robot base frame
world_frame	map	World coordinate frame

Topics

Subscriptions

Topic	Type	Description
/text_nav/command	std_msgs/String	Text command to navigate to
/textmap/markers	visualization_msgs/MarkerArray	Landmark markers for visualization

Publications

Topic	Type	Description
/text_nav/status	std_msgs/String	Navigation status updates
/text_nav/goal_marker	visualization_msgs/Marker	Goal visualization in RViz

RViz Displays

The provided text_nav.rviz config includes:

Display	Topic	Description
Map	/map	2D occupancy grid
TF	—	Robot position
Global Plan	/plan	Path to goal
Local Plan	/local_plan	Obstacle-avoidance path
Local Costmap	/local_costmap/costmap	Cost map around robot
Nav Goal Marker	/text_nav/goal_marker	Goal arrow marker
Text Landmarks	/textmap/markers	Text landmark labels

License

Apache License 2.0