Gazebo Sitl Plugin

A ROS-independent Gazebo plugin for Ardupilot's SITL.

Requirements

* Python 2.7+ (to generate mavlink headers)
* MavProxy (https://github.com/Dronecode/MAVProxy)
* Ardupilot (https://github.com/ArduPilot/ardupilot)

Build

1. Make sure you have initialized and updated the Mavlink submodule at least once with:

   git submodule init
   git submodule update
   

2. Create a build folder and make using CMAKE as follows:

   mkdir build
   cd build
   cmake ..
   make
   cd -
   

3. Download Gazebo models if necessary:

   Gazebo automatically searches and downloads models referenced in the .world file that are not already present in ~/.gazebo/models or in GAZEBO_MODEL_PATH. However, in some cases the download might take a long time for no apparent reason. Download the Quadrotor model manually with:

   mkdir -p ~/.gazebo/models
   curl http://models.gazebosim.org/quadrotor/model.tar.gz | tar xvz -C ~/.gazebo/models
   

Run

1. Open a second terminal and run Ardupilot:

   ${ARDUPILOTDIR}/build/sitl/bin/arducopter-quad --model x
   

2. In a third terminal, run Mavproxy:

   mavproxy.py --master tcp:127.0.0.1:5760 --out udp:127.0.0.1:14556 --streamrate -1
   

   Load the Parameters on Mavproxy Prompt:

   param load ./parameters/gzsitl.parm
   

3. Set environment variables and open the Gazebo gzsitl_drone_target world file with the following command:

   GAZEBO_PLUGIN_PATH=${GAZEBO_PLUGIN_PATH}:${PWD}/build/gzsitl GAZEBO_MODEL_PATH=${GAZEBO_MODEL_PATH}:${PWD}/models gazebo ./world/gzsitl_drone_target.world --verbose
   

Interaction

The Plugin first detects if the vehicle being simulated on SITL is Landed or already Airborne.

• If Landed, store the initial position as home, set flight mode as guided and request take-off.
• If Airborne, request home position, and keep the current flight mode.

When Airborne, the vehicle follows the transparent sphere (target).

Throubleshooting

Gazebo might fail to open if the needed models or plugins are not found. If that happens, make sure the environment variable GAZEBO_PLUGIN_PATH is correctly pointing to the build folder and that the environment variable GAZEBO_MODEL_PATH is pointing to the models folder. The Gazebo --verbose terminal output is useful for determining wether a plugin or a models has not not been found.