Smart Drone System

A simulated drone system built with ROS 2 Lyrical on Fedora 44. This project demonstrates core ROS 2 concepts through a multi-node drone simulation with publishers, subscribers, services, actions, custom messages, parameters, and launch files.

Architecture

                         /drone/sensors
 sensor_node ─────────────────────────────► state_machine_node
 (Python)     ─────────────────────────────► ground_station_node
                    /drone/state
                                                    │
 command_node ──── takeoff/land ──► state_machine_node
 (Python)        ── goto ─────────► controller_node
                         /drone/cmd_waypoint (action)

Nodes

Node	Language	Description
sensor_node	Python	Publishes simulated sensor data (altitude, battery, GPS, temperature) at 10Hz
state_machine_node	Python	Manages drone state transitions (IDLE, TAKING_OFF, FLYING, etc.)
controller_node	Python	Executes movement commands and handles waypoint navigation action
ground_station_node	Python	Monitors telemetry and displays a formatted dashboard
command_node	Python	CLI tool to send commands (takeoff, land, goto, emergency)

Custom Interfaces

Type	Name	Fields
Message	SensorData	altitude, battery, latitude, longitude, temperature, voltage
Message	DroneState	state, battery, altitude, latitude, longitude
Service	Takeoff	Request: target_altitude; Response: success, message
Service	Land	Request: confirm; Response: success, message
Service	EmergencyStop	Request: reason; Response: success, message
Action	GoToWaypoint	Goal: latitude, longitude, altitude; Feedback: current_lat/lng/alt, distance_remaining; Result: success, message

Prerequisites

• Fedora 44 (KDE Plasma or other desktop)
• ROS 2 Lyrical desktop (installed via COPR, includes ros2 CLI and dev tools)
• GCC/G++ compiler
• Python 3.10+

Installation

1. Install ROS 2 Lyrical via COPR

# Enable the COPR repository (flagship for Fedora 44)
sudo dnf copr enable hellaenergy/ros2

# Install ROS 2 desktop (includes ros2 CLI, launch, demo nodes, rqt)
sudo dnf install ros-lyrical-ros-desktop

# Install interface generators (required for custom .msg/.srv/.action)
sudo dnf install ros-lyrical-rosidl-default-generators ros-lyrical-rosidl-default-runtime

# Source ROS 2 (add to ~/.bashrc for persistence)
echo "source /opt/ros/lyrical/setup.bash" >> ~/.bashrc
source /opt/ros/lyrical/setup.bash

2. Install Build Tools

sudo dnf install -y gcc-c++ cmake python3-colcon-common-extensions python3-rosdep

3. Verify ROS 2 Installation

# Check ROS 2 is working
ros2 --help

# Run the talker/listener demo to verify
# Terminal 1:
ros2 run demo_nodes_cpp talker

# Terminal 2:
ros2 run demo_nodes_py listener

4. Clone and Build

# Clone the repository
git clone https://github.com/Je0Dev/ros2-tutorial-drones.git
cd ros2-tutorial-drones

# Build drone_interfaces first (custom interfaces must be built before drone_system)
colcon build --packages-select drone_interfaces
source install/setup.bash

# Build drone_system (Python nodes)
colcon build --packages-select drone_system
source install/setup.bash

# Fix ros2 run: create wrapper scripts (required due to missing ament_python in Lyrical)
chmod +x install/drone_system/lib/drone_system/* 2>/dev/null

Usage

Launch the Full System

Note: ros2 launch is not available in this Lyrical build. Use the wrapper script instead:

./build.sh   # builds and creates ros2 run wrappers
# Then run individual nodes in separate terminals (see below)

Run Individual Nodes

# Terminal 1: Sensor data
ros2 run drone_system sensor_node

# Terminal 2: State machine
ros2 run drone_system state_machine_node

# Terminal 3: Controller
ros2 run drone_system controller_node

# Terminal 4: Ground station monitor
ros2 run drone_system ground_station_node

Send Commands

# Takeoff to 10 meters
ros2 run drone_system command_node takeoff 10.0

# Navigate to a waypoint
ros2 run drone_system command_node goto 37.7749 -122.4194 15.0

# Land
ros2 run drone_system command_node land

# Emergency stop
ros2 run drone_system command_node emergency "Low battery"

View ROS 2 Graph

ros2 node list
ros2 topic list
ros2 service list
ros2 action list

Project Structure

ros2-tutorial/
├── README.md
├── LICENSE                    # Apache 2.0
├── CONTRIBUTING.md
├── AGENTS.md                  # AI agent instructions
├── CONSTRAINTS.md             # Safety guardrails
├── .gitignore
└── src/
    ├── drone_interfaces/      # Custom message, service, action definitions
    │   ├── msg/
    │   ├── srv/
    │   ├── action/
    │   ├── CMakeLists.txt
    │   └── package.xml
    └── drone_system/          # All node implementations (Python)
        ├── drone_system/      # Python nodes
        ├── launch/            # Launch files
        ├── config/            # Parameter files
        ├── test/              # Tests
        ├── setup.py
        └── package.xml

ROS 2 Concepts Covered

Concept	Implementation
Publishers	sensor_node publishes SensorData on /drone/sensors
Subscribers	state_machine_node, ground_station_node subscribe to topics
Services	Takeoff, Land, EmergencyStop service servers
Actions	GoToWaypoint action server in controller_node
Custom Messages	SensorData, DroneState
Custom Services	Takeoff, Land, EmergencyStop
Custom Actions	GoToWaypoint
Parameters	battery_warn_threshold, max_altitude, sensor_rate, etc.
TimerCallbacks	sensor_node uses timers for periodic publishing

Configuration

Parameters are defined in src/drone_system/config/params.yaml:

sensor_node:
  ros__parameters:
    sensor_rate: 10.0
    initial_altitude: 0.0
    initial_battery: 100.0
    battery_drain_rate: 0.1

state_machine_node:
  ros__parameters:
    battery_warn_threshold: 20.0
    battery_critical_threshold: 10.0
    max_altitude: 120.0

License

This project is licensed under the Apache License 2.0 - see the LICENSE file for details.

Contributing

See CONTRIBUTING.md for guidelines on how to contribute.