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2026-01-02 21:45:16 +00:00

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ArduPilot SITL + Gazebo Integration

This guide explains how to run the drone simulation with ArduPilot Software-In-The-Loop (SITL) and MAVProxy, providing a realistic flight controller stack.

Overview

The ArduPilot integration replaces the simple velocity control with a full ArduPilot flight stack:

┌──────────────────┐     ┌─────────────────┐     ┌──────────────────┐
│  ArduPilot SITL  │◄───►│  Gazebo + Plugin │◄───►│  MAVLink Bridge  │
│  (Flight Control)│ JSON│  (Physics Sim)   │ ROS │  + Controllers   │
└──────────────────┘     └─────────────────┘     └──────────────────┘
        ▲                                                    │
        │ UDP                                               │
        │                                                    ▼
┌──────────────────┐                              ┌──────────────────┐
│    MAVProxy      │◄────────────────────────────►│ DroneController  │
│    (GCS)         │     MAVLink Commands         │ (Your Algorithm) │
└──────────────────┘                              └──────────────────┘

Components

Component	Description
ArduPilot SITL	Full autopilot firmware running in simulation
ardupilot_gazebo	Plugin connecting Gazebo physics to ArduPilot
MAVProxy	Ground Control Station for monitoring/commands
MAVLink Bridge	ROS 2 node bridging MAVLink ↔ ROS topics
Drone Controller	Your landing algorithm

Prerequisites

1. ArduPilot SITL

Install ArduPilot development environment:

# Ubuntu/Debian
git clone https://github.com/ArduPilot/ardupilot.git ~/ardupilot
cd ~/ardupilot
git submodule update --init --recursive
Tools/environment_install/install-prereqs-ubuntu.sh -y
. ~/.profile

# Set environment
echo 'export PATH=$PATH:$HOME/ardupilot/Tools/autotest' >> ~/.bashrc
echo 'export ARDUPILOT_HOME=$HOME/ardupilot' >> ~/.bashrc
source ~/.bashrc

2. ArduPilot Gazebo Plugin

Install the ardupilot_gazebo plugin:

# For Gazebo Garden/Harmonic
git clone https://github.com/ArduPilot/ardupilot_gazebo.git ~/ardupilot_gazebo
cd ~/ardupilot_gazebo
mkdir build && cd build
cmake .. -DCMAKE_BUILD_TYPE=Release
make -j4

# Add to Gazebo plugin path
echo 'export GZ_SIM_SYSTEM_PLUGIN_PATH=$HOME/ardupilot_gazebo/build:$GZ_SIM_SYSTEM_PLUGIN_PATH' >> ~/.bashrc
echo 'export GZ_SIM_RESOURCE_PATH=$HOME/ardupilot_gazebo/models:$HOME/ardupilot_gazebo/worlds:$GZ_SIM_RESOURCE_PATH' >> ~/.bashrc
source ~/.bashrc

3. pymavlink

pip install pymavlink

Quick Start

Option 1: Integrated Launch (Recommended)

This starts everything together:

# Terminal 1: Start Gazebo
ros2 launch gazebo/launch/ardupilot_drone.launch.py

# Terminal 2: Start SITL
cd ~/ardupilot
sim_vehicle.py -v ArduCopter -f gazebo-iris --model JSON --console --map

# Terminal 3: Run bridge + controllers
python run_ardupilot.py --no-sitl --pattern circular

Option 2: Manual Setup

# Terminal 1: Start Gazebo world
gz sim -r gazebo/worlds/ardupilot_drone.sdf

# Terminal 2: Start ArduPilot SITL
cd ~/ardupilot
sim_vehicle.py -v ArduCopter -f gazebo-iris --model JSON --console

# Terminal 3: Run MAVLink bridge + controllers
python run_ardupilot.py --no-sitl

Option 3: Full Automatic

# Starts everything (requires SITL installed)
python run_ardupilot.py --pattern circular --console --map

Flight Operations

Using MAVProxy Commands

Once connected, use MAVProxy to control the drone:

# Set GUIDED mode for algorithm control
mode guided

# Arm motors
arm throttle

# Take off to 5 meters
takeoff 5

# Land
mode land

# Disarm
disarm

Using the MAVLink Bridge API

From Python, you can control the drone directly:

from mavlink_bridge import MAVLinkBridge

# Create bridge
bridge = MAVLinkBridge(sitl_port=14550)

# Arm and takeoff
bridge.set_mode('GUIDED')
bridge.arm()
bridge.takeoff(altitude=5.0)

# Land
bridge.land()

Files

File	Description
`mavlink_bridge.py`	ROS 2 ↔ MAVLink bridge
`run_ardupilot.py`	Integrated launcher
`gazebo/worlds/ardupilot_drone.sdf`	Gazebo world with ArduPilot plugin
`gazebo/launch/ardupilot_drone.launch.py`	ROS 2 launch file

Configuration

Edit config.py to adjust ArduPilot settings:

ARDUPILOT = {
    "vehicle": "ArduCopter",      # ArduCopter, ArduPlane, APMrover2
    "frame": "gazebo-iris",       # Gazebo frame
    "sitl_host": "127.0.0.1",
    "sitl_port": 5760,
    "mavproxy_port": 14550,
}

MAVLINK = {
    "system_id": 1,
    "component_id": 191,
    "heartbeat_timeout": 5.0,
}

Telemetry Format

The MAVLink bridge publishes telemetry in the same format as other modes:

{
    "imu": {
        "orientation": {"roll": 0.0, "pitch": 0.0, "yaw": 0.0},
        "angular_velocity": {"x": 0.0, "y": 0.0, "z": 0.0}
    },
    "altimeter": {
        "altitude": 5.0,
        "vertical_velocity": 0.0
    },
    "velocity": {"x": 0.0, "y": 0.0, "z": 0.0},
    "position": {"x": 0.0, "y": 0.0, "z": 5.0},
    "landing_pad": {
        "relative_x": 0.5,
        "relative_y": 0.2,
        "distance": 4.8,
        "confidence": 0.95
    },
    "battery": {"voltage": 12.6, "remaining": 100},
    "armed": true,
    "flight_mode": "GUIDED",
    "connected": true
}

Troubleshooting

SITL Not Starting

# Check if SITL is installed
which sim_vehicle.py

# Set ArduPilot path
export ARDUPILOT_HOME=~/ardupilot
export PATH=$PATH:$ARDUPILOT_HOME/Tools/autotest

Gazebo Plugin Not Found

# Check plugin path
echo $GZ_SIM_SYSTEM_PLUGIN_PATH

# Verify plugin exists
ls ~/ardupilot_gazebo/build/libArduPilotPlugin.so

No MAVLink Connection

# Check if SITL is listening
netstat -tuln | grep 14550

# Test with mavlink console
python -c "from pymavlink import mavutil; c = mavutil.mavlink_connection('udpin:127.0.0.1:14550'); print(c.wait_heartbeat())"

Drone Won't Arm

Common issues:

Pre-arm checks failing - Check MAVProxy console for errors
GPS required - In simulation, you may need to wait for GPS lock
EKF not ready - Wait for EKF to initialize

Disable pre-arm checks for testing (not recommended for real flights):

# In MAVProxy
param set ARMING_CHECK 0

Flight Modes

Mode	Description
GUIDED	Accept velocity/position commands from controller
LOITER	Hold position (GPS required)
ALT_HOLD	Maintain altitude, manual horizontal
LAND	Automatic landing
STABILIZE	Attitude stabilization only

For autonomous landing, use GUIDED mode.

Architecture Comparison

Feature	Simple Gazebo	ArduPilot + Gazebo
Flight Controller	Velocity control	Full ArduPilot
Stabilization	Manual PD	Inbuilt EKF + PID
Flight Modes	None	All ArduPilot modes
Arming	Not required	Safety checks
Failsafes	None	Battery, GPS, etc.
MAVLink	No	Full protocol
GCS Support	No	QGC, Mission Planner
Realism	Low	High

7.5 KiB Raw Blame History