RDC_Simulation/docs/architecture.md

Architecture Overview

Operation Modes

1. Standalone (Any Platform)

Single process, no ROS 2 required:

python standalone_simulation.py --pattern circular

┌────────────────────────────────────────┐
│      standalone_simulation.py          │
│  ┌──────────────────────────────────┐  │
│  │  PyBullet Physics + Camera       │  │
│  │  Built-in Controller             │  │
│  │  Rover Movement                  │  │
│  └──────────────────────────────────┘  │
└────────────────────────────────────────┘

2. Gazebo + ROS 2 (2 Terminals)

Terminal 1:

ros2 launch gazebo/launch/drone_landing.launch.py

Terminal 2:

python run_gazebo.py --pattern circular

Terminal 1                    Terminal 2
┌───────────────────┐        ┌───────────────────┐
│ Gazebo + Bridge   │◄──────►│ run_gazebo.py     │
│ (Physics)         │  ROS   │ + Controllers     │
└───────────────────┘        └───────────────────┘

3. ArduPilot SITL (2 Terminals)

Terminal 1:

ros2 launch ardupilot_gz_bringup iris_runway.launch.py

Terminal 2:

mavproxy.py --console --map --master=:14550

┌─────────────────────────────────────────────┐
│        Single Launch Command                │
│   (Starts SITL + Gazebo + RViz)            │
├─────────────────────────────────────────────┤
│  ArduPilot SITL ◄──► Gazebo ◄──► ROS 2     │
│       ▲                                     │
│       │ /ap/* topics                        │
│       ▼                                     │
│  MAVProxy (GCS)                            │
└─────────────────────────────────────────────┘

Key Components

Component	Description
drone_controller.py	Your landing algorithm
gazebo_bridge.py	Gazebo ↔ ROS bridge
mavlink_bridge.py	MAVLink commands
camera_viewer.py	Camera display

ROS 2 Topics

Topic	Direction	Description
/drone/telemetry	←	Sensor data (JSON)
/cmd_vel	→	Velocity commands
/drone/camera	←	Camera images
/rover/telemetry	←	Landing pad position

ArduPilot Topics

Topic	Type
/ap/pose/filtered	Position
/ap/twist/filtered	Velocity
/ap/imu/filtered	IMU
/ap/battery	Battery