repository·ros2·Indexed 22 days ago
https://github.com/mavlink/mavrosAn extendable communication node for ROS that enables seamless communication between the Robot Operating System (ROS) and MAVLink-enabled flight controllers such as PX4 or ArduPilot. The project includes the core mavros package, mavros_extras for specialized plugins (e.g., gimbal_control, px4flow), the libmavconn library for independent MAVLink connections, and mavros_examples for ROS 2 implementation demonstrations.
MAVROS is a MAVLink-to-ROS 2 bridge designed for PX4, ArduPilot, and other MAVLink-based autopilots. The project is organized into several key packages:
mavros: Contains the core ROS 2 nodes, including the Router, UAS, and standard plugins.mavros_extras: Provides optional plugins for extended functionality.mavros_msgs: Defines the ROS 2 message and service interfaces used for communication.libmavconn: The underlying MAVLink transport library.MAVROS is an extendable communication node for ROS that facilitates MAVLink communication. The repository is organized into several functional packages:
mavconn library, which can be used independently of the ROS environment.mavros_examples package provides hands-on demonstrations for implementing MAVROS services and topics within the ROS 2 ecosystem. It is designed to help users learn how to communicate with autopilot systems running ArduPilot or PX4 firmware using standardized ROS interfaces. The package serves as a practical reference to ensure code complies with the latest MAVROS API specifications and best practices, avoiding issues with deprecated or renamed topics and services.The LandingTargetPlugin (namespace landing_target) is designed to facilitate landing target tracking. It can either publish the location of a landing area (captured via a downward-facing camera) to the Flight Control Unit (FCU) or receive landing target tracking data coming from the FCU.
~/pose_in (geometry_msgs/msg/PoseStamped): Publishes the target pose.~/lt_marker (geometry_msgs/msg/Vector3Stamped): Publishes the landing target marker.~/raw (mavros_msgs/msg/LandingTarget): Receives raw landing target data.~/pose (geometry_msgs/msg/PoseStamped): Receives target pose data.LANDING_TARGET MAVLink message (ID 149, common dialect).LANDING_TARGET MAVLink message (ID 149, common dialect) to the FCU.The OpticalFlowPlugin (part of mavros_extras) allows you to bridge Optical Flow camera data between MAVLink and ROS. It can publish raw optical flow data and ground distance to ROS topics, and can also subscribe to ROS topics to send optical flow data back to the flight controller via MAVLink.
Key Functionality:
OPTICAL_FLOW messages and publishes them to ROS topics.~/raw/send and publishes to MAVLink OPTICAL_FLOW messages.MAVROS handles several types of coordinate transformations:
MAVROS translates Aerospace NED (North-East-Down) frames used by FCUs to ROS ENU (East-North-Up) frames.
Using GeographicLib, MAVROS supports:
earth frame in ECEF local coordinates (per ROS REP 105).map frame in ECEF and calculating the offset to it in ENU.The LocalPositionPlugin (class mavros::std_plugins::LocalPositionPlugin) provides ROS messages representing the vehicle's local position, velocity, and acceleration. It converts MAVLink local position data into standard ROS messages and can also publish transforms (TF) to represent the vehicle's pose in the world frame.
// Implementation reference
// Namespace: local_position
// Class: mavros::std_plugins::LocalPositionPluginmavros::std_plugins::IMUPlugin) is responsible for publishing IMU, attitude, and related sensor data from MAVLink messages to ROS topics. It subscribes to various MAVLink IMU and attitude messages to provide processed sensor readings.PX4FlowPlugin (class mavros::extra_plugins::PX4FlowPlugin) is an extra plugin in MAVROS that bridges PX4Flow camera data to ROS. It subscribes to MAVLink OPTICAL_FLOW_RAD messages and publishes the data as ROS messages, including optical flow rates, ground distance, and temperature.The setpoint_raw plugin (class mavros::std_plugins::SetpointRawPlugin) allows you to send raw position, global, or attitude setpoints to the flight controller. It supports a 'return loop' where the current state is published back to ROS.
Users can control which specific fields are sent to the flight controller by using the IGNORE bits within the message structures. This allows for fine-grained control over whether you are commanding position, velocity, acceleration, or attitude components.
The cam_imu_sync plugin (class mavros::extra_plugins::CamIMUSyncPlugin) is used to synchronize external camera systems with the Flight Control Unit (FCU). It works by publishing a timestamp indicating when the FCU triggered the external camera. By correlating the Sequence ID from the MAVLink message with the image sequence from the camera, you can determine the exact shutter trigger time.
CAMERA_TRIGGER (MAVLink message ID 112, dialect: common).handle_cam_trig handler to process incoming camera trigger messages.distance_sensor plugin enables the bidirectional exchange of distance sensor data between a companion computer (connected via USB/Serial) and the Flight Control Unit (FCU). It allows you to publish distance sensor data to the FCU or subscribe to distance sensor data coming from the FCU.