145 lines
6.2 KiB
Markdown
145 lines
6.2 KiB
Markdown
# Architecture Overview
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GPS-denied drone landing simulation with multiple operation modes.
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## Operation Modes
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### 1. Standalone Mode (Any Platform)
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Single-process simulation - no ROS 2 or networking required:
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```
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┌────────────────────────────────────────┐
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│ standalone_simulation.py │
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│ ┌──────────────────────────────────┐ │
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│ │ PyBullet Physics + Camera │ │
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│ │ Built-in Landing Controller │ │
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│ │ Rover Movement Patterns │ │
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│ │ Configuration from config.py │ │
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│ └──────────────────────────────────┘ │
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└────────────────────────────────────────┘
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```
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### 2. PyBullet + ROS 2 Mode (Two Terminals)
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```
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Terminal 1 Terminal 2
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┌──────────────────┐ ┌──────────────────────────┐
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│ simulation_host │◄─UDP───►│ run_bridge.py │
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│ (PyBullet) │ │ ┌────────────────────┐ │
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│ Port 5555 │ │ │ ROS2SimulatorBridge│ │
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│ │ │ │ DroneController │ │
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│ │ │ │ RoverController │ │
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└──────────────────┘ │ └────────────────────┘ │
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└──────────────────────────┘
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```
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Data flow:
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- RoverController publishes position → Bridge sends to Simulator
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- Simulator moves rover visually AND sends back telemetry
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- DroneController receives telemetry, publishes commands
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- Bridge forwards commands to Simulator
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### 3. Gazebo + ROS 2 Mode (Two Terminals, Linux/WSL2)
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```
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Terminal 1 Terminal 2
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┌───────────────────────────┐ ┌──────────────────────────┐
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│ ros2 launch ... .launch.py│ │ run_gazebo.py │
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│ ┌─────────────────────┐ │ │ ┌────────────────────┐ │
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│ │ Gazebo (ign gazebo) │ │ │ │ GazeboBridge │ │
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│ │ - Drone (vel ctrl) │ │◄────►│ │ DroneController │ │
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│ │ - Rover (vel ctrl) │ │ ROS │ │ RoverController │ │
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│ ├─────────────────────┤ │ │ └────────────────────┘ │
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│ │ ros_gz_bridge │ │ └──────────────────────────┘
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│ └─────────────────────┘ │
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└───────────────────────────┘
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```
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Data flow:
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- RoverController publishes to `/rover/cmd_vel` → Gazebo moves rover
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- Gazebo publishes odometry → GazeboBridge converts to telemetry
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- DroneController receives telemetry, publishes to `/cmd_vel`
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- GazeboBridge forwards to `/drone/cmd_vel` → Gazebo moves drone
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## Components
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| File | Description |
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|------|-------------|
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| `config.py` | Central configuration (positions, physics, gains) |
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| `standalone_simulation.py` | All-in-one simulation |
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| `simulation_host.py` | PyBullet physics server (UDP) |
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| `run_bridge.py` | PyBullet bridge + controllers |
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| `run_gazebo.py` | Gazebo bridge + controllers |
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| `drone_controller.py` | **Your landing algorithm** |
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| `rover_controller.py` | Moving landing pad |
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| `ros_bridge.py` | ROS-UDP bridge (used by run_bridge.py) |
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| `gazebo_bridge.py` | Gazebo-ROS bridge (used by run_gazebo.py) |
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| `gazebo/launch/drone_landing.launch.py` | ROS 2 launch file for Gazebo |
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| `gazebo/worlds/drone_landing.sdf` | Gazebo world with drone + rover |
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## ROS 2 Topics
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| Topic | Type | Description |
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|-------|------|-------------|
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| `/cmd_vel` | `Twist` | Drone commands from DroneController |
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| `/drone/cmd_vel` | `Twist` | Drone commands to Gazebo |
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| `/drone/telemetry` | `String` | GPS-denied sensor data (JSON) |
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| `/rover/cmd_vel` | `Twist` | Rover velocity to simulator |
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| `/rover/telemetry` | `String` | Rover position (JSON) |
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## Network Configuration
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All components default to `0.0.0.0` for network accessibility.
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### Remote Setup (PyBullet mode)
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**Machine 1 (with display):**
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```bash
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python simulation_host.py # Listens on 0.0.0.0:5555
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```
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**Machine 2 (headless controller):**
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```bash
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python run_bridge.py --host 192.168.1.100
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```
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### UDP Ports
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| Port | Direction | Content |
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|------|-----------|---------|
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| 5555 | Bridge → Simulator | Commands (JSON) |
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| 5556 | Simulator → Bridge | Telemetry (JSON) |
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## GPS-Denied Sensors
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All modes provide the same sensor data:
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| Sensor | Data |
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|--------|------|
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| **IMU** | Orientation (roll, pitch, yaw), angular velocity |
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| **Altimeter** | Altitude above ground, vertical velocity |
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| **Velocity** | Estimated velocity (x, y, z) |
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| **Camera** | 320x240 downward JPEG (base64) |
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| **Landing Pad** | Relative position (x, y, distance) when visible |
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## Configuration (config.py)
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| Section | Parameters |
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|---------|------------|
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| `DRONE` | mass, size, color, start_position, thrust/torque scales |
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| `ROVER` | size, color, start_position, default_pattern, default_speed |
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| `CAMERA` | width, height, fov, jpeg_quality |
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| `PHYSICS` | gravity, timestep, telemetry_rate |
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| `CONTROLLER` | Kp_z, Kd_z, Kp_xy, Kd_xy, rate |
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| `LANDING` | success_distance, success_velocity, height_threshold |
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| `NETWORK` | host, command_port, telemetry_port |
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## Platform Support
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| Mode | Ubuntu | Arch | macOS | Windows | WSL2 |
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|------|--------|------|-------|---------|------|
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| Standalone | ✅ | ✅ | ✅ | ✅ | ✅ |
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| PyBullet+ROS | ✅ | ⚠️ | ❌ | ❌ | ✅ |
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| Gazebo+ROS | ✅ | ⚠️ | ❌ | ❌ | ✅ |
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