Simulation (Gazebo + ArduPilot / PX4 SITL)¶

Fly the same missions you run on hardware, in Gazebo with ArduPilot or PX4 SITL — no vehicle required. Install once per firmware, then start the simulator and the ROS bridge in two terminals.

Install¶

One install command per firmware. ArduPilot pulls ArduCopter SITL, Gazebo, the ros_gz bridge, and the ArduPilot Gazebo plugin (auto-selecting the Gazebo version per ROS distro; per-distro table in the Docker guide). PX4 pulls PX4-Autopilot and Gazebo and symlinks the Nectar shared assets into the PX4 tree.

ArduPilotPX4BothPX4 native (uXRCE-DDS)

make sim-install FIRMWARE=ardupilot   # ArduCopter SITL + Gazebo + plugin

make sim-install FIRMWARE=px4          # PX4 SITL + Gazebo + Nectar assets

make sim-install FIRMWARE=all          # ArduPilot + PX4

For PX4 uXRCE-DDS (PROTOCOL=dds), also install the native agent and px4_msgs once:

make sim-install FIRMWARE=px4 ARGS=--native

Docker with Gazebo¶

INSTALL_GAZEBO=true make docker-build
INSTALL_GAZEBO=true ROS_DISTRO=jazzy make docker-build

See the Docker guide for more options.

Running the simulation¶

Two terminals, the same pattern for both firmwares: the simulator (terminal 1) plus the ROS stack (terminal 2). Choose FIRMWARE / ENV / PROTOCOL (defaults: ardupilot / outdoor / mavros).

Match ENV between terminals

Use the same FIRMWARE and ENV in terminal 1 (sim-start) and terminal 2 (sim-bridge). Indoor adds the vision pipeline; outdoor uses GPS.

Setup	Terminal 1 (simulator)	Terminal 2 (ROS stack)
ArduPilot outdoor / MAVROS (default)	`make sim-start`	`make sim-bridge`
ArduPilot outdoor / direct MAVLink	`make sim-start FIRMWARE=ardupilot ENV=outdoor`	`make sim-bridge FIRMWARE=ardupilot ENV=outdoor PROTOCOL=mavlink`
ArduPilot indoor (vision)	`make sim-start FIRMWARE=ardupilot ENV=indoor`	`make sim-bridge FIRMWARE=ardupilot ENV=indoor`
PX4 outdoor / MAVROS	`make sim-start FIRMWARE=px4 ENV=outdoor`	`make sim-bridge FIRMWARE=px4 ENV=outdoor`
PX4 outdoor / direct MAVLink	`make sim-start FIRMWARE=px4 ENV=outdoor`	`make sim-bridge FIRMWARE=px4 ENV=outdoor PROTOCOL=mavlink`
PX4 outdoor / uXRCE-DDS	`make sim-start FIRMWARE=px4 ENV=outdoor`	`make sim-bridge FIRMWARE=px4 ENV=outdoor PROTOCOL=dds`
PX4 indoor (onboard VIO)	`make sim-start FIRMWARE=px4 ENV=indoor`	`make sim-bridge FIRMWARE=px4 ENV=indoor`
PX4 indoor / direct MAVLink	`make sim-start FIRMWARE=px4 ENV=indoor`	`make sim-bridge FIRMWARE=px4 ENV=indoor PROTOCOL=mavlink`

PX4 direct MAVLink (PROTOCOL=mavlink): terminal 2 skips MAVROS and starts camera bridges only; the mission connects to PX4 offboard UDP 14540 itself (px4_mavlink backend).

PX4 uXRCE-DDS (PROTOCOL=dds): terminal 2 runs MicroXRCEAgent on UDP :8888; use the px4_dds backend in your mission. Requires the one-time ARGS=--native install above.

Stop everything (both firmwares) with make sim-stop.

Then run a mission against it, e.g.:

nectar-activate
python3 nectar/nectar/examples/control/basic.py --drone mavros --mode position --side 2.0

See the Simulation module for the full matrix, the vision pipeline, and the automated test suite.