ROSbot 3 - ROS 2 API

Detailed information about content of rosbot package for ROS2.

ROS API

Available Nodes

🤖	🖥️	NODE	DESCRIPTION
✅	✅	controller_manager	Controller Manager performs two main functions. First, it manages controllers and their required interfaces, handling tasks like loading, activating, deactivating, and unloading. Second, it interacts with hardware components, ensuring access to their interfaces. controller_manager/controller_manager
✅	✅	ekf_node	Used to fuse wheel odometry and IMU data. Parameters are defined in rosbot_bringup/config/ekf.yaml robot_localization/ekf_node
❌	✅	/gz_bridge	Transmits Gazebo simulation data to the ROS layer ros_gz_bridge/parameter_bridge
❌	✅	gz_ros_control	Responsible for integrating the ros2_control controller architecture with the Gazebo simulator. gz_ros2_control/gz_ros2_control
✅	✅	imu_broadcaster	The broadcaster to publish readings of IMU sensors imu_sensor_broadcaster/imu_sensor_broadcaster
✅	❌	imu_sensor_node	The node responsible for subscriptions to IMU data from the hardware rosbot_hardware_interfaces/rosbot_imu_sensor
✅	✅	joint_state_broadcaster	The broadcaster reads all state interfaces and reports them on specific topics joint_state_broadcaster/joint_state_broadcaster
✅	✅	laser_filter	This is a filter that removes points in a laser scan inside of a cartesian box laser_filters/scan_to_scan_filter_chain
✅	✅	robot_state_publisher	Uses the URDF specified by the parameter robot*description and the joint positions from the topic joint*states to calculate the forward kinematics of the robot and publish the results using tf robot_state_publisher/robot_state_publisher
✅	❌	rosbot_system_node	The node communicating with the hardware responsible for receiving and sending data related to engine control rosbot_hardware_interfaces/rosbot_system
✅	✅	rosbot_base_controller	The controller managing a mobile robot with a differential or omni drive (mecanum wheels). Converts speed commands for the robot body to wheel commands for the base. It also calculates odometry based on hardware feedback and shares it.DiffDriveController or MecanumDriveController diff_drive_controller/diff_drive_controller
❌	✅	rosbot_gz_bridge	Transmits data about the robot between the Gazebo simulator and ROS. ros_gz_bridge/parameter_bridge
✅	❌	/stm32_node	Node responsible for communication with hardware. micro_ros_agent/micro_ros_agent

Available Topics

🤖	🖥️	TOPIC	DESCRIPTION
✅	❌	/battery_state	Provides information about the state of the battery. sensor_msgs/BatteryState
✅	✅	cmd_vel	Sends velocity commands for controlling robot motion. geometry_msgs/Twist
✅	✅	diagnostics	Contains diagnostic information about the robot's systems. diagnostic_msgs/DiagnosticArray
✅	✅	dynamic_joint_states	Publishes information about the dynamic state of joints. control_msgs/DynamicJointState
✅	✅	imu_broadcaster/imu	Broadcasts IMU (Inertial Measurement Unit) data. sensor_msgs/Imu
✅	✅	imu_broadcaster/transition_event	Signals transition events in the lifecycle of the IMU broadcaster node. lifecycle_msgs/TransitionEvent
✅	✅	joint_state_broadcaster/transition_event	Indicates transition events in the lifecycle of the joint state broadcaster node. lifecycle_msgs/TransitionEvent
✅	✅	joint_states	Publishes information about the state of robot joints. sensor_msgs/JointState
✅	✅	odometry/filtered	Publishes filtered odometry data. nav_msgs/Odometry
✅	✅	robot_description	Publishes the robot's description. std_msgs/String
✅	✅	rosbot_base_controller/odom	Provides odometry data from the base controller of the ROSbot XL. nav_msgs/Odometry
✅	✅	rosbot_base_controller/transition_event	Indicates transition events in the lifecycle of the ROSbot XL base controller node. lifecycle_msgs/TransitionEvent
✅	✅	scan	Publishes raw laser scan data. sensor_msgs/LaserScan
✅	✅	scan_filtered	Publishes filtered laser scan data. sensor_msgs/LaserScan
✅	✅	set_pose	Sets the robot's pose with covariance. geometry_msgs/PoseWithCovarianceStamped
✅	✅	tf	Publishes transformations between coordinate frames over time. tf2_msgs/TFMessage
✅	✅	tf_static	Publishes static transformations between coordinate frames. tf2_msgs/TFMessage

Hidden topic:

TOPIC	DESCRIPTION
/_imu/data_raw	raw data image from imu sensor sensor_msgs/Imu
/_motors_cmd	desired speed on each wheel std_msgs/Float32MultiArray
/_motors_responses	raw data readings from each wheel sensor_msgs/JointState

Package Description

rosbot

Metapackage that contains dependencies to other repositories. It is also used to define whether simulation dependencies should be used.

rosbot_bringup

The main package responsible for running the physical robot.

Available Launch Files:

• bringup.launch.py - is responsible for communicating with firmware and activating all logic related to the robot's movement and processing of sensory data.
• microros.launch.py - establishes connection with the hardware using microROS agent.

rosbot_controller

ROS2 hardware controller for ROSbot. It manages inputs and outputs data from ROS2 control, forwarding it via ROS topics to be read by microROS. The controller.launch.py file loads the robot model defined in rosbot_description along with ROS2 control dependencies from rosbot_hardware_interfaces.

Available Launch Files:

• controller.launch.py - starts controllers related to ros2_control responsible for driving, communication with imu and joint_states publications

rosbot_description

URDF model used for both simulation and as a source of transforms on physical robot. It was written to be compatible with ROS Industrial and preconfigured for ROS2 control.

Available Launch Files:

• load_urdf.launch.py - starts controllers related to ros2_control responsible for driving, communication with imu and joint_states publications
• rviz.launch.py - Launches the ready-made RViz configuration

Main Description Files:

• rosbot.urdf.xacro - Final configuration of ROSbot.
• rosbot_xl.urdf.xacro - Final configuration of ROSbot XL.

rosbot_gazebo

Launch files for Gazebo working with ROS2 control.

Available Launch Files:

• simulations.launch.py - Runs simulations with a defined robot and all sensors on it.
• spawn_robot.launch.py - Allow to spawn new robot in already running simulation.

rosbot_localization

A package related to the logic responsible for performing sensor fusion.

Available Launch Files:

• ekf.launch.py - Runs ekf filter which fuse wheel odometry with imu data.

rosbot_utils

A package containing auxiliary filters that integrate simple external packages.

Available Launch Files:

• laser_filter.launch.py - launch laser filter responsible for filtering out the laser scan points located inside the robot base.