tutorial01

Tutorial 1) Running ED with a configuration file

Prerequisites

• https://github.com/tue-robotics/ed.git
• https://github.com/tue-robotics/ed_gui_server.git
• https://github.com/tue-robotics/ed_rviz_plugins.git

Tutorial

ED strongly relies on plugins to integrate sensor data, estimate object positions, recognize objects, etc. The plugins are discovered by the exports from the package.xml files. To get an overview of all defined plugins, use the list_plugin tool:

rosrun ed list_plugins

You can start ED by running:

rosrun ed ed

This will start the ED server which holds the world data structure. However, no world data is loaded, so the ED instance is quite useless at the moment. The world data that should be loaded and the plugins that should be started can be specified in a configuration file. Then, it's simply a matter of running ED like this:

rosrun ed ed CONFIG-FILE

The configuration file should be written in a YAML-format and mainly consists of two parts: a world specification, and a list of plugins. The first determines what the world looks like, the second what we want to do with the world representation. Create a file called 'my-ed-config.yaml' and put this in:

world:
- id: block1
  pose: { x: 2, y: 0, z: 0.5 }
  shape:
    box:
      size: { x: 0.5, y: 0.5, z: 1 }
- id: block2
  pose: { x: 3, y: 2, z: 0.75 }
  shape:
    box:
      size: { x: 0.5, y: 0.5, z: 1.5 }

plugins:
  - name: gui_server
    type: ed_gui_server/gui_server

Take some time to try to understand what the config file states. A world is specified consisting of two objects - we'll call these entities. Both entities have an ID, a position in the world, and a shape. The shape is described as being a box with a certain size. Furthermore, we specify that we want to run the gui_server plugin. This will allow us to visualize the world in RViz.

Now, run ED and point it to the configuration file created above, like:

rosrun ed ed <path/to/my-ed-config.yaml>

For example, if we are still in the same folder as the configuration file:

rosrun ed ed my-ed-config.yaml

You probably won't see a lot happening. But ED is running. To visualize the world we have described, we need to run another node. This is some sort of proxy which communicates over a low-bandwidth channel with the ED GUI server plugin and generates visualization markers, which are typically high-bandwidth. This is useful: when running ED on the robot, make sure you run the proxy on a local machine. The local machine will communicate with the robot over a low-bandwidth topic, while RViz will 'listen' to the high-bandwidth visualization markers which are produced on the same local machine. To run the proxy:

rosrun ed_gui_server ed_rviz_publisher

Now start RViz, and listen to the Marker topic /ed/rviz. You should see two blocks appearing: the blocks you specified in the configuration file. Or use the rviz_plugin from the ed_rviz_plugins package to visualize.

You can also use the rviz plugin: Start rviz and add the ed_rviz_plugins/WorldModel display. Configure the service for querying the meshes and the ED entities topic, e.g. /ed/gui/entities and /ed/gui/query_meshes.