Files
simulation/README.md
2026-02-09 03:49:39 +00:00

254 lines
8.6 KiB
Markdown

# UAV-UGV Gazebo SITL Simulation
## GPS-Denied Navigation with Geofencing
A complete simulation environment for UAV (drone) and UGV (ground vehicle) development using **GPS-denied navigation** with vision-based localization, while maintaining GPS-based geofencing for safety.
## Key Feature: GPS-Denied Navigation
**Navigation Mode**: All vehicles navigate using **relative positioning** only:
- Visual odometry from cameras
- Optical flow sensors
- IMU integration
- Visual landmark tracking
- Local coordinate frames
**GPS Usage**: GPS is ONLY used for:
- Geofencing (safety boundaries)
- Initial position reference (optional)
- NOT used for waypoint navigation
- NOT used for position control
This simulates real-world GPS-denied environments like:
- Indoor spaces
- Urban canyons
- GPS-jammed areas
- Under bridges/tunnels
## Features
- **Iris quadcopter** with dual cameras (forward + downward)
- **Ground vehicle (UGV)** with vision sensors
- **Visual odometry** - camera-based position estimation
- **Optical flow** - velocity estimation from downward camera
- **Landmark navigation** - visual feature tracking
- **GPS geofencing** - safety boundaries only
- **Single command launch** - everything runs from one script
- **NVIDIA GPU acceleration** support
- **Python virtual environment** for isolated dependencies
- **GPS-denied worlds** - indoor and urban environments
## System Requirements
- **Ubuntu 22.04 LTS** (or 24.04 with ROS 2 Jazzy)
- **Python 3.10+**
- **ROS 2 Humble** (or Jazzy for Ubuntu 24.04)
- 8GB RAM minimum (16GB recommended)
- NVIDIA GPU recommended
### WSL2 Support (Windows)
This project supports **Windows Subsystem for Linux (WSL2)**:
- Windows 10 (21H2+) or Windows 11
- WSL2 with Ubuntu 22.04
- GUI support via WSLg (Windows 11) or VcXsrv (Windows 10)
- See [WSL Setup Guide](docs/wsl_setup_guide.md) for detailed instructions
## Quick Start
### Linux (Native)
```bash
# 1. Clone repository
cd ~/ros2_ws/src
git clone https://git.sirblob.co/SirBlob/simulation.git uav_ugv_simulation
cd uav_ugv_simulation
# 2. Run setup (installs everything)
bash setup.sh
# 3. Restart terminal or reload bash
source ~/.bashrc
# 4. Activate virtual environment and run
source activate_venv.sh
bash scripts/run_simulation.sh
```
### WSL2 (Windows)
```bash
# 1. Clone repository
cd ~
git clone https://git.sirblob.co/SirBlob/simulation.git uav_ugv_simulation
cd uav_ugv_simulation
# 2. Run WSL-specific setup
bash scripts/setup_wsl.sh
# 3. Restart terminal
exit
# Reopen WSL terminal
# 4. Run simulation
cd ~/uav_ugv_simulation
source activate_venv.sh
bash scripts/run_simulation.sh
# If graphics are slow, use software rendering:
bash scripts/run_simulation.sh --software-render
```
## GPS-Denied Navigation Architecture
```
┌─────────────────────────────────────────────────────┐
│ Vision Sensors │
│ Forward Camera + Downward Camera + Optical Flow │
└─────────────────┬───────────────────────────────────┘
┌─────────────────────────────────────────────────────┐
│ Visual Odometry & Feature Tracking │
│ Estimates relative position from camera motion │
└─────────────────┬───────────────────────────────────┘
┌─────────────────────────────────────────────────────┐
│ Position Estimator (EKF Fusion) │
│ Fuses: Visual Odom + Optical Flow + IMU │
│ Output: Local position estimate (relative) │
└─────────────────┬───────────────────────────────────┘
┌─────────────────────────────────────────────────────┐
│ Navigation Controller │
│ Commands: "Move 5m forward, 3m right" │
│ (Relative coordinates only, NO GPS waypoints) │
└─────────────────────────────────────────────────────┘
SEPARATE SAFETY LAYER (GPS-based):
┌─────────────────────────────────────────────────────┐
│ Geofence Monitor │
│ GPS position → Check against boundaries │
│ If outside: Emergency RTL or hold │
└─────────────────────────────────────────────────────┘
```
## Navigation Modes
### 1. **Vision-Only Mode** (Default)
- Uses camera for all position estimates
- Suitable for structured environments
- Requires good lighting and visual features
### 2. **Optical Flow Mode**
- Uses downward camera for velocity
- Works well at low altitudes
- Good for hovering and slow flight
### 3. **Hybrid Mode**
- Combines visual odometry + optical flow + IMU
- Most robust approach
- Recommended for complex missions
## Geofencing Configuration
Edit `config/geofence_params.yaml`:
```yaml
geofence:
enabled: true
use_gps: true # GPS ONLY for geofence
# Define boundaries (GPS coordinates)
fence_type: "polygon" # or "circle"
# Polygon fence (lat/lon points)
polygon_points:
- {lat: 47.397742, lon: 8.545594} # Point 1
- {lat: 47.398242, lon: 8.545594} # Point 2
- {lat: 47.398242, lon: 8.546094} # Point 3
- {lat: 47.397742, lon: 8.546094} # Point 4
# Or circle fence
center_lat: 47.397742
center_lon: 8.545594
radius_meters: 100
# Actions on breach
action: "RTL" # Return to launch
max_altitude: 50 # meters
```
## Example Mission (Relative Coordinates)
```python
# Example: Navigate to visual landmark
# Define mission in RELATIVE coordinates
mission_waypoints = [
{"x": 0, "y": 0, "z": 5}, # Takeoff to 5m
{"x": 10, "y": 0, "z": 5}, # Move 10m forward
{"x": 10, "y": 5, "z": 5}, # Move 5m right
{"x": 0, "y": 5, "z": 5}, # Return to start (offset)
{"x": 0, "y": 0, "z": 5}, # Back to takeoff point
{"x": 0, "y": 0, "z": 0}, # Land
]
# GPS is NEVER used for these waypoints
# Position estimated from visual odometry
```
## Project Structure
- `launch/` - ROS 2 launch files
- `worlds/` - Gazebo world files (indoor, urban)
- `models/` - Robot models (Iris with cameras, UGV)
- `src/vision/` - Visual odometry, optical flow
- `src/localization/` - Position estimation, sensor fusion
- `src/navigation/` - Path planning (relative coordinates)
- `src/safety/` - Geofencing (GPS-based)
- `config/` - Configuration files
## Documentation
- [Setup Guide](docs/setup_guide.md) - Linux installation
- [WSL Setup Guide](docs/wsl_setup_guide.md) - Windows WSL2 installation
- [Usage Guide](docs/usage.md)
- [Architecture Overview](docs/architecture.md)
- [GPS-Denied Navigation](docs/gps_denied_navigation.md)
- [Troubleshooting](docs/troubleshooting.md)
## Key Differences from GPS Navigation
| Aspect | GPS Navigation | This Project (GPS-Denied) |
|--------|---------------|---------------------------|
| Position Source | GPS satellites | Visual odometry + sensors |
| Waypoint Type | GPS coordinates | Relative coordinates (x,y,z) |
| Reference Frame | Global (lat/lon) | Local (relative to start) |
| Indoor Capability | No | Yes |
| Drift | Minimal | Accumulates over time |
| Geofencing | GPS-based | GPS-based (safety only) |
| Use Cases | Outdoor, open sky | Indoor, urban, GPS-jammed |
## Running Different Scenarios
```bash
# Indoor warehouse (no GPS available)
bash scripts/run_simulation.sh --world worlds/indoor_warehouse.world
# Urban canyon (degraded GPS)
bash scripts/run_simulation.sh --world worlds/urban_canyon.world
# Open outdoor (GPS available but not used for nav)
bash scripts/run_simulation.sh --world worlds/empty_custom.world
```
## License
MIT License
## Contributing
Contributions welcome! Please ensure all navigation remains GPS-denied (except geofencing).