AirSim + ArduPilot SITL + QGroundControl (Pixi)

Complete isolated simulation environment for AirSim with ArduPilot SITL and QGroundControl using pixi for dependency management.

🎯 Overview

This repository provides a fully isolated simulation environment for AirSim with ArduPilot SITL without polluting your system with manual apt installs. All dependencies are managed through pixi (conda-based), ensuring reproducibility and clean builds.

What's Included

1. AirSim - Unreal Engine-based simulator (AirSimNH environment)
2. ArduPilot SITL - Software-in-the-loop flight controller (ArduCopter)
3. QGroundControl - Ground control station for mission planning

All components downloaded and configured in .airsim_ardupilot/ directory.

📋 Prerequisites

• Ubuntu 22.04 (tested)
• pixi installed (Installation Guide)
• Git

🚀 Quick Start

1. Install Dependencies

Initialize the Pixi environment with all required build tools and Python packages:

pixi install

This will create an isolated simulation environment with:

• Build toolchain (gcc, g++, make, pkg-config, ccache)
• Development tools (git, wget, unzip, zip, rsync)
• Python packages (empy, pexpect, dronecan, pymavlink, MAVProxy, etc.)

2. Activate Pixi Environment

Enter the pixi environment:

pixi shell

All subsequent commands should be run within this shell.

3. Download and Build Components

Download AirSim Environment

pixi run download-airsim

This will:

• Download AirSimNH environment (v1.8.1) from Microsoft AirSim releases
• Extract to .airsim_ardupilot/airsim/AirSimNH/
• Copy configuration from config/airsim/settings.json
• Create symlink at ~/Documents/AirSim/settings.json

Download QGroundControl

pixi run download-qground

This will:

• Download latest QGroundControl AppImage
• Save to .airsim_ardupilot/qgroundcontrol/
• Make executable automatically

Build ArduPilot SITL

Compile ArduCopter for SITL:

pixi run build-ardupilot

This will:

• Clone ArduPilot repository (if not present)
• Update all submodules
• Configure and build ArduCopter binary for SITL
• Output binary at .airsim_ardupilot/ardupilot/build/sitl/bin/arducopter

Build options:

• --clean - Remove previous build artifacts
• --force-clone - Delete and re-clone ArduPilot repository

4. Verify Installation

Check that all components are ready:

pixi run check

This validates:

• ✅ AirSim environment and launcher
• ✅ QGroundControl AppImage
• ✅ ArduPilot SITL binary
• ✅ Pixi environment status

🔧 Configuration

AirSim Settings

Configuration file: config/airsim/settings.json

Key settings:

• Vehicle Type: ArduCopter
• Origin: Lat -7.2823507, Lon 112.7923504, Alt 20m
• Ports: UDP 9003, Control 9002
• Camera: 1280x720, 90° FOV, pitch -90°
• Sensors: Barometer, IMU, GPS, Magnetometer enabled
• ViewMode: FlyWithMe (default)

ArduPilot Parameters

Configuration file: config/ardupilot/airsim.parm

Optimized parameters for AirSim SITL:

• SCHED_LOOP_RATE=180 - Reduced scheduler rate for stability
• WPNAV_SPEED=140 - Limited waypoint speed (5 km/h)
• ANGLE_MAX=1500 - Restricted attitude authority
• WPNAV_ACCEL=50 - Smooth waypoint acceleration
• SIM_SPEEDUP=20 - Simulation speedup factor
• GPS and failsafe thresholds relaxed for testing

🚁 Running the Simulation

Simple Run (Recommended)

Start all components together:

pixi run simulation

Options:

• --no-display - Run AirSim in headless mode (NoDisplay)
• --help - Show usage information

This will:

1. Update ViewMode in settings.json based on display flag
2. Start QGroundControl (background)
3. Start AirSim environment (background)
4. Start ArduPilot SITL with parameter file (foreground)

Press Ctrl+C to stop all components gracefully.

Manual Component Startup

If you prefer to start components individually:

# Terminal 1: QGroundControl
.airsim_ardupilot/qgroundcontrol/QGroundControl-x86_64.AppImage

# Terminal 2: AirSim
.airsim_ardupilot/airsim/AirSimNH/LinuxNoEditor/AirSimNH.sh

# Terminal 3: ArduPilot SITL (in pixi shell)
cd .airsim_ardupilot/ardupilot
python3 Tools/autotest/sim_vehicle.py -v ArduCopter --model airsim-copter \
  --console --map --out=127.0.0.1:14550 --out=127.0.0.1:14551 \
  --add-param-file=../../config/ardupilot/airsim.parm

⚙️ Environment Variables

• AIRSIM_HOME - Base directory for all components (default: ./.airsim_ardupilot)
• AIRSIM_ENV_RELEASE - AirSim release tag (default: v1.8.1)
• ARDUPILOT_REPO_URL - ArduPilot repository URL
• QGC_URL - QGroundControl download URL

📁 Directory Structure

airsim-qgroundcontrol-ardupilot-sitl-pixi/
├── pixi.toml                        # Pixi environment configuration
├── pixi.lock                        # Locked dependencies
├── README.md                        # This file
├── config/                          # Configuration files
│   ├── airsim/
│   │   └── settings.json            # AirSim settings template
│   └── ardupilot/
│       └── airsim.parm              # ArduPilot parameters
├── scripts/                         # Build and utility scripts
│   ├── download-airsim.sh           # Download AirSim environment
│   ├── download-qground.sh          # Download QGroundControl
│   ├── build-ardupilot-sitl.sh      # Build ArduPilot SITL
│   ├── check-simulation.sh          # Verify installation
│   └── run-simulation.sh            # Run all components
└── .airsim_ardupilot/               # Workspace (created by scripts)
    ├── airsim/
    │   ├── AirSimNH/                # Unreal Engine environment
    │   └── settings.json            # Active AirSim configuration
    ├── qgroundcontrol/
    │   └── QGroundControl-x86_64.AppImage
    └── ardupilot/
        ├── build/sitl/bin/arducopter
        └── Tools/autotest/sim_vehicle.py

🔧 Pixi Environment Details

The simulation environment defined in pixi.toml provides:

From Pixi (conda environment)

• Python 3.11-3.12
• Build toolchain (gcc, g++, make, pkg-config, ccache)
• Development tools (git, wget, unzip, zip, rsync)

PyPI Packages

• empy 3.3.4 (template engine for ArduPilot waf)
• pexpect (process automation)
• dronecan (DroneCAN/UAVCAN support)
• future (Python 2/3 compatibility)
• pymavlink (MAVLink protocol library)
• MAVProxy (MAVLink proxy and command shell)
• pyserial (serial communication)
• packaging, monotonic (utility libraries)

🆘 Troubleshooting

Build Errors

If ArduPilot build fails:

pixi run build-ardupilot --clean

Missing Dependencies

Ensure you're in the Pixi environment:

pixi shell

Settings Not Applied

Re-run the download script to reset settings:

rm -rf .airsim_ardupilot/airsim/settings.json
pixi run download-airsim

📝 Notes

• Isolation: All components installed in .airsim_ardupilot/ directory
• No System Pollution: No manual apt install required
• Reproducible: pixi.lock ensures identical dependency versions
• Auto Configuration: ArduPilot parameters automatically loaded on startup
• MAVLink: QGroundControl connects on port 14550, telemetry on 14551

📚 References

• AirSim GitHub
• ArduPilot Documentation
• QGroundControl User Guide
• Pixi Documentation
• MAVLink Protocol

📄 License

Follow respective licenses of:

• ArduPilot: GPLv3
• AirSim: MIT License
• QGroundControl: Apache 2.0 / GPLv3
• This build system: Use freely

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Built with ❤️ using Pixi for clean, reproducible simulation environments