2.7 KiB
2.7 KiB
PyBullet Simulation
Running the GPS-denied drone simulation with PyBullet.
Quick Start
Terminal 1 - Simulator:
source activate.sh
python simulation_host.py
Terminal 2 - ROS Bridge:
source activate.sh
python ros_bridge.py
Terminal 3 - Controllers:
source activate.sh
python controllers.py --pattern circular --speed 0.3
Remote Setup
Run simulator on one machine, controllers on another.
Machine 1 (with display):
python simulation_host.py
Machine 2 (headless):
source activate.sh
python ros_bridge.py --host <MACHINE_1_IP>
python controllers.py
Simulation Parameters
| Parameter | Value |
|---|---|
| Physics Rate | 240 Hz |
| Telemetry Rate | 24 Hz |
| Drone Mass | 1.0 kg |
| Gravity | -9.81 m/s² |
GPS-Denied Sensors
The simulator provides:
| Sensor | Description |
|---|---|
| IMU | Orientation (roll, pitch, yaw), angular velocity |
| Altimeter | Barometric altitude, vertical velocity |
| Velocity | Optical flow estimate (x, y, z) |
| Camera | 320x240 downward JPEG image |
| Landing Pad | Vision-based relative position (60° FOV, 10m range) |
Camera System
PyBullet renders a camera image from the drone's perspective:
| Property | Value |
|---|---|
| Resolution | 320 x 240 |
| FOV | 60 degrees |
| Format | Base64 encoded JPEG |
| Update Rate | ~5 Hz |
| Direction | Downward-facing |
The image is included in telemetry as camera.image.
World Setup
| Object | Position | Description |
|---|---|---|
| Ground | z = 0 | Infinite plane |
| Rover | (0, 0, 0.15) | 1m × 1m landing pad |
| Drone | (0, 0, 5) | Starting position |
UDP Communication
| Port | Direction | Data |
|---|---|---|
| 5555 | Bridge → Sim | Commands (JSON) |
| 5556 | Sim → Bridge | Telemetry (JSON with camera) |
ROS Bridge Options
python ros_bridge.py --help
Options:
--host, -H Simulator IP (default: 127.0.0.1)
--port, -p Simulator port (default: 5555)
Building Executable
Create standalone executable:
source activate.sh
python build_exe.py
Output: dist/simulation_host (or .exe on Windows)
Troubleshooting
"Cannot connect to X server"
PyBullet requires a display:
- Run on machine with monitor
- Use X11 forwarding:
ssh -X user@host - Virtual display:
xvfb-run python simulation_host.py
Drone flies erratically
Reduce control gains:
Kp = 0.3
Kd = 0.2
No telemetry received
- Check simulator is running
- Verify firewall allows UDP 5555-5556
- Check IP address in ros_bridge.py
Camera image not appearing
Ensure PIL/Pillow is installed:
pip install pillow