06. Debugging in ROS - rqt common plugins

Debugging with rqt common plugins

RQT common plugins are a suite of tools you have seen before. We will mention several tools that you have seen before, but also learn several new ones as well!

Errors in ROS

rqt console

ROS errors can be broken down into certain verbosity levels. This is helpful when trying to decide which problems to address first. The types are as follows:

  • DEBUG
  • INFO
  • WARN
  • FAILURE
  • FATAL

Examples of each can be found here.

With all of these errors flying around all over the place, it can be hard to isolate a particular issue. In comes rqt_console. It aggregates all of the log messages and allows you to sort them.

Per documentation each message includes:

  • Message: The message specified by the user
  • Severity: The severity level of the message, e.g. Debug, Info, etc.
  • Node: The name of the node which broadcast the message
  • Time: The time at which the message was broadcast
  • Topics: The topics advertised by the node broadcasting the message
  • Location: Combines the file, function and line using colons

Source

To catch all of the messages, be sure to start rqt_console before launching any other ROS related code.

rqt_image_view

This is a great tool to visualize images streaming from camera and depth maps from sensors. Use it to make sure you are properly receiving the data you want on its specific topic.

rqt _graph

As you saw in the previous project rqt graph is a great tool to visualize the connections of your robotic system. Be sure to use this to check that everything is working in its intended fashion.

Here is an example output from your previous SLAM Lab:

Further Resources: rqt_common_plugins