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UH-ECE6397 / Swarmathon-ROS

ROS control libraries, 3D models, and scripts for NASA Swarmathon robots
http://nasaswarmathon.com/
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ROS Meeting Wednesday #9

Closed AlpNov closed 8 years ago

AlpNov commented 8 years ago

@UH-ECE6397/students @UH-ECE6397/staff

Hey guys, here's a summary of what happened in the meeting today and preps for the workshop on Wednesday, Mar 02, 11 AM in room S391.

1. ROS tutorials review

As mentioned last week, if you have done the ROS tutorials, I'll be happy to answer any questions you have regarding them. Email me at an.nguyen.vn@ieee.org or open an issue on github and tag me using @AlpNov.

For Wednesday, if you have done something with ROS outside of the tutorial and think that this could be beneficial to the class. Please let me know and we can see about adding it to the workshop.

2. Basics of Swarmathon ROS

After you've gone through the ROS tutorials, we can start looking at the Swarmathon ROS code. This will be the activity for the week. Once you execute ./run.sh, you need to consider the following:

  1. What nodes/topics are established by each robot and the GUI. Use the tools rosnode, rostopic and rqt_graph. It might be helpful to consult the ROS tutorials concerning them as well as their ROS wiki articles.
  2. Which files are executed to start a node? examine the launch files, under the launch folder under rover_workspace.
  3. Write some debugging message. You can use ROS_INFO like printf or like cpp cout style (see rosconsole). With Swarmathon ROS, these messages will not be printed out to the console, you can examine them with rqt_console, the tutorial have mentioned this, and you can read more on rqt_console's wiki article.

We'll brush on this a bit for Wednesday, as well as continue exploring these for the rest of the week.

3. Some news
  1. The swarmie robot are operational when we run roscore and the GUI on the robot's computer. However when roscore and the GUI run on the a central laptop, communicating with the swarmie nodes on the robot, we can get sensor information but no mobility.
  2. There's been a couple of significant update the the Swarmathon code base from UNM, mainly regarding the new API for the competition. We'll need the update our code as well as learn how to use the new API.
  3. The webinar that happened on Friday, Feb 26th was recorded. Please review it. Also review the posts on the Swarmathon forum there are some interesting questions in there.

Thank you,

An Nguyen

AlpNov commented 8 years ago

Meeting Summary

1. ROS Tutorial

Some folks have gotten through the tutorial, and have started on reading the Swarmathon code base, starting with the mobility.cpp file. Some folks are still working through it, bit by bit. Stick with it guys, the learning curve is a bit steep, but it'll be worth it!

Some of the difficulties I've seen so far:

  1. Linux file system navigation, Linux commands
  2. File editing

Talk to your friends to work it out, and feel free to email me if you have questions, troubles, or just don't know where or how to proceed.

2. Swarmathon competition goals

Ultimate goal for this week is to have a general understanding of the state machine in the mobility.cpp. To demonstrate that understanding, I suggest using ROS_INFO and rqt_console to print a message from the robot in one of the handler function.

3. Monday meeting

On Monday we'll talk about the Swarmathon code. Come with questions and suggestions. We might try to do a flow chart of the state machine, then identify some areas we can improve.

Thanks,

An Nguyen