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RflySim Toolchain Docs

ROS/ROS2 Interfaces

ROS/ROS2 Interface Reference¶

The RflySim toolchain supports communication with the simulation system via ROS 1 (Noetic) and ROS 2 (Humble/Jazzy), and mainly uses MAVROS / MAVROS2 to implement the bridge between PX4 and the ROS ecosystem.

MAVROS Overview¶

MAVROS is a bridge that connects the PX4 autopilot to the ROS ecosystem, responsible for converting MAVLink messages into ROS topics and services:

graph LR
    PX4[PX4 SITL/HITL] <-->|MAVLink<br>UDP| MAVROS[MAVROS]
    MAVROS <-->|ROS Topics/Services| ROS[ROS Nodes]
    ROS --> ALGO[Perception/Planning/Control Algorithms]

Common ROS Topics¶

Subscribed Topics (Read Status)¶

Topic	Message Type	Description
`/mavros/state`	`mavros_msgs/State`	Autopilot connection/arming/flight mode status
`/mavros/local_position/pose`	`geometry_msgs/PoseStamped`	Position and attitude in local coordinate frame
`/mavros/local_position/velocity_local`	`geometry_msgs/TwistStamped`	Velocity in local frame
`/mavros/global_position/global`	`sensor_msgs/NavSatFix`	GPS global coordinates
`/mavros/imu/data`	`sensor_msgs/Imu`	IMU data
`/mavros/battery`	`sensor_msgs/BatteryState`	Battery status

Published Topics (Send Control Commands)¶

Topic	Message Type	Description
`/mavros/setpoint_position/local`	`geometry_msgs/PoseStamped`	Position setpoint
`/mavros/setpoint_velocity/cmd_vel_unstamped`	`geometry_msgs/Twist`	Velocity setpoint
`/mavros/setpoint_raw/local`	`mavros_msgs/PositionTarget`	Raw position/velocity/acceleration setpoint
`/mavros/setpoint_raw/attitude`	`mavros_msgs/AttitudeTarget`	Attitude setpoint

Common Services¶

Service	Type	Description
`/mavros/cmd/arming`	`mavros_msgs/CommandBool`	Arm/Disarm
`/mavros/set_mode`	`mavros_msgs/SetMode`	Switch flight mode
`/mavros/cmd/takeoff`	`mavros_msgs/CommandTOL`	Takeoff
`/mavros/cmd/land`	`mavros_msgs/CommandTOL`	Land

ROS 2 (uXRCE-DDS)¶

PX4 v1.14+ natively supports ROS 2 communication. Through Micro XRCE-DDS Agent, uORB messages are directly converted into ROS 2 topics, no MAVROS required:

graph LR
    PX4[PX4] <-->|uXRCE-DDS| AGENT[Micro XRCE-DDS Agent]
    AGENT <-->|ROS 2 Topics| ROS2[ROS 2 Nodes]

Quick Start¶

ROS 1 + MAVROS¶

# Execute in WinWSL
# Start MAVROS and connect to SITL (default port 14540)
roslaunch mavros px4.launch fcu_url:="udp://:14540@127.0.0.1:14557"

Or use the shortcut RflyTools\MavrosRun.

ROS 2 + MAVROS2¶

# Execute in WinWSL
ros2 launch mavros px4.launch fcu_url:="udp://:14540@127.0.0.1:14557"

Example	Path
MAVROS Function Test	`RflySimAPIs\2.RflySimUsage\0.ApiExps\e6_ROSMavrosReadme`
ROS Visual Perception	`RflySimAPIs\8.VisionPerception\`
ROS Swarm Control	`RflySimAPIs\10.SwarmControl\`