Ardupilot Sitl Plugin with its own model?

[Arthyfice]

Hi Mr. Roy,

I am currently working on a project which uses your great plugin.
To set up the environment, I followed the tutorial of Erle-Robotics (http://docs.erlerobotics.com/simulation/vehicles/erle_copter/tutorial_1).
I succeeded to implement that on an Ubuntu 16 with ROS Kinectic.
All works well, but I'd like to implement my own urdf instead of the Erle model.
I created my urdf file and after that I launch one node which spawns this created model (it's the same node that Erle-Robotics : rover_spawn.launch but with a different urdf spawner corresponding to mine).
But I don't figure out why am I obtained this following error ?
I parsed my urdf file and it works well.

[ INFO] [1529323526.421671909, 0.075000000]: Searching joints... terminate called after throwing an instance of 'gazebo::common::Exception' [INFO] [1529323526.421970, 0.075000]: Spawn status: SpawnModel: Successfully spawned entity Aborted (core dumped) [spawn_rover-3] process has finished cleanly log file: /home/arthy/.ros/log/e16e3740-72ef-11e8-b8e2-2c56dcdcef4a/spawn_rover-3*.log [gazebo-4] process has died [pid 9263, exit code 134, cmd /home/arthy/simulation/ros_catkin_ws/src/gazebo_ros_pkgs/gazebo_ros/scripts/gzserver -u -e ode /home/arthy/simulation/ros_catkin_ws/src/ardupilot_sitl_gazebo_plugin/ardupilot_sitl_gazebo_plugin/worlds/rover_world/rover.world __name:=gazebo __log:=/home/arthy/.ros/log/e16e3740-72ef-11e8-b8e2-2c56dcdcef4a/gazebo-4.log]. log file: /home/arthy/.ros/log/e16e3740-72ef-11e8-b8e2-2c56dcdcef4a/gazebo-4*.log
In the file apm_plugin_gazebo_side.cpp, I don't figure out how I must do different in order to implement my urdf file, or why it didn't work with just modifiying the urdf file.