# ArduPilot GPS-Denied Simulation

Realistic flight controller simulation without GPS.

## Quick Start (2 Terminals)

**Terminal 1:**
```bash
./scripts/run_ardupilot_sim.sh camera
```

**Terminal 2:**
```bash
sim_vehicle.py -v ArduCopter -f gazebo-iris --model JSON --console

# GPS-denied mode:
param set ARMING_CHECK 0
mode stabilize
arm throttle force
```

## Installation

```bash
./setup/install_ardupilot.sh
source ~/.bashrc
```

Installs: ArduPilot SITL, Gazebo, ardupilot_gazebo plugin, MAVProxy

## GPS-Denied Configuration

In MAVProxy console:

```bash
# Disable all pre-arm checks
param set ARMING_CHECK 0

# GPS-free flight modes
mode stabilize      # Manual with stabilization
mode alt_hold       # Altitude hold
mode guided_nogps   # Guided without GPS
```

## GPU Support

The launcher auto-detects your GPU:

| GPU | Status |
|-----|--------|
| NVIDIA | Best performance |
| Intel integrated | Good for laptops |
| AMD | Good performance |
| Software | Works but slow |

## Camera Feed

### In Gazebo GUI
Click camera icon → Select drone camera

### Using camera_viewer
```bash
ros2 run ros_gz_bridge parameter_bridge /drone/camera@sensor_msgs/msg/Image[gz.msgs.Image
python camera_viewer.py --topic /drone/camera
```

## World Options

```bash
./scripts/run_ardupilot_sim.sh runway   # Default
./scripts/run_ardupilot_sim.sh camera   # With camera
```

## MAVProxy Commands

```bash
mode stabilize     # Manual mode
mode guided_nogps  # Autonomous (no GPS)
arm throttle force # Arm motors
takeoff 5          # Takeoff 5m
mode land          # Land
```

## Troubleshooting

### Simulation laggy
```bash
glxinfo | grep "OpenGL renderer"
# Should show GPU, not "llvmpipe"
```

### Can't arm
```bash
param set ARMING_CHECK 0
arm throttle force
```

### No camera
Use `./scripts/run_ardupilot_sim.sh camera` for camera world.