USING GAZEBO

GAZEBO

 

Gazebo is a part of the Player Project. It is a 3D simulator utilising ODE and OGRE. ROS has incorporated Gazebo into their distributions with some minor modification.

GAZEBO@ROS WITH WORLD FILES - A DETOUR FROM THE USUAL

Gazebo, while it is a part of Player Project is usually used with world files. However, ROS tutorials recommend using Gazebo with launch files - these launch file scripts identify the corresponding world file.

However in the spirit of Player/Stage/Gazebo it is possible to run Gazebo with world files from its executable, located at /opt/ros/diamondback/stacks/simulator_gazebo/gazebo/bin .

Thus using ./gazebo with pioneer2dx.world, which is a well known Player Project world file;

1. Start an instance of roscore - gazebo is built with slight modification, so an instance of master (roscore) is needed. The later scripts search for the master.
   
2. Navigate to the gazebo executables directory ( cd /opt/ros/diamondback/stacks/simulator_gazebo/gazebo/bin)  
3. Start Gazebo with pioneer2dx.world file (./gazebo /path/to/pioneer2dx.world)
4. The following window should pop up,  

Trying the rxgraph to check the ROS nodes at work;

Trying with pioneer2at.world file;

The same works for Stage, the executables at /opt/ros/diamondback/stacks/simulator_stage/stage/bin  can be used in a similar manner. The executables, stage and stageros work same with a world file giving 2D simulations. However stage is the primitive Player Project executable and doesn't need a roscore master while stageros is more 'ROS like', needs roscore and works with ROS nodes. 

NOTE 

1. Tested on ROS 1.4.9 Diamondback (Gazebo 0.10.0 and Stage 3.2.2)     
2. pioneer2dx.world and pioneer2at.world files can be found in Gazebo installation files (viz. gazebo-0.10.0/worlds)
3. An alternative is to use, roscore and rosrun gazebo gazebo /path/to/pioneer2dx.world file

REFERENCES

(1) I thank John Hsu for his help

(2) stage vs. stageros 

(3) launch files for gazebo

(4) N.Koenig, A.Howard,"Design and Use Paradigms for Gazebo, An Open-Source Multi-Robot Simulator"
(5) Gazebo Test at Care-O-Bot webpage