This week, most of the graduate students and Dr. Adamczyk were absent. They attended a conference where they presented their projects to other scientists. Our goal for this week was to test the TorsoBot with the motion capture and get the kicker to work. Unfortunately, the interns are not super knowledgeable about how the motion capture works. We all learned how to set it up, but we started having errors that we didn't know how to solve. So, we shifted our focus to the kicker. We detached the legs on the kicker and moved them a little bit more clockwise. However, the more we messed with the robot, the less it seemed to work.
I also made more progress on the robotic arm. To find where the errors were coming from, I made a copy of our launch file and deleted nodes line by line until the errors disappeared. The errors seem to be coming from a program called set_waypoints_from_svg. This program has a couple different nodes and topics so I spent a day testing each topic to see what messages were being published to them. I found a couple of different problems through this process. One, that a node called set_waypoints did not appear to exist and two, that the waypoint_complete topic always publishes true. The first is a big problem as the set_waypoints node is what tells the robot where it needs to move to. The second is a problem because the waypoint_complete topic is what tells the robot that it has moved to the waypoint. If this topic always publishes true, the robot will think that it has reached its target even if it hasn't.
I took time to read more books on python and ROS hoping that I would find a solution to these issues. Although the problems persisted, I learned many new things. For example, I learned terminal commands for python and the different ways you can use rospy.log. This module (rospy.log) can be used to send messages to a special and universal topic called /rosout. Also, rospy.log can choose a level of severity for its message. The message could be fatal (ie: rospy.logfatal) or debug (ie: rospy.logdebug) or any of the other levels in between like error, info, and warn. I thought that this module was the key to printing variable values, but I still was unable to get it to function properly. Although, I did learn that it requires a second argument other than the message you want to send. I worked on figuring out what should be filled in that second argument.
If you know a lot about ROS and have any suggestions, feel free to use the contact form on my home page or leave a comment on my ROS answers query here.
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