Thread: How to determine root cause of robot dropping from Teleop to Disabled during match.
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Unread 24-03-2015, 07:09
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FRC #1718 (The Fighting Pi)
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Location: Armada, Michigan
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Re: How to determine root cause of robot dropping from Teleop to Disabled during matc
Quote:
Originally Posted by tr6scott View Post
At West Michigan.
Match SemiFinal 2
Video of match: https://www.youtube.com/watch?v=ib3zz6QXHbc
Robot in question is 2137 TORC, bottom right hand corner.

We experienced two "field disconnects" in this match, the first one lasted about a second, and the second one lasted about 3/10ths of a second.

This data comes from our logging on the roborio on the bot. Our logging completed on the bot, is only done during autonomous and teleop, so when we dropped to the disabled state, we didn't log data, but I can tell this based on the gaps in the data time stamp. These events are highlighted yellow in the attached robot log file.

I am the lead electrical and programming mentor, but was not at the event. I am doing a postmortem trying to determine the root cause. The team was told by the FTA that the issue was not with the field, and there no basis for a replay. TORC bounced back from this anomaly, and the alliance was able to capture the blue banner.

Based on our log data, I know the roboRio did not lose power or reset. From the length of time of the glitch, only being a second, that the robot radio probably was not the cause, as that is a typical 30 second reboot. Also, the robot worked fine after the comms were re-established, but our elevator carriage had been sprung from the frame, rendering it useless. In the video, you can see the drivers and FTA moving the driver station around, and the robot springing back to life. You can also see the stack light go from solid red, to flashing red, back to solid red.

We should have driver station logs available on Tuesday, when we unpack, so one of the questions is what should I be looking for in the driver station logs for this match? I have not done much with the driver station logs, as we typically try to log what is important to us on the bot itself. Can you point me to a doc that describes driver station log files, and how to read the data?

A couple other questions for my general knowledge, what determines if who is at fault on a FRC field, when a glitch occurs?
What data determines this, and do we have access to this?

Just a general comment about the field at West Michigan. There seemed to be many delays, much more than any of the other fields in Michigan, along with more replays on the West Michigan field than the other two. Just an observation as I watched the other two webcasts play finals, while we were trying to finish quarter finals.

Thanks for any help.
I'm sure you noticed that one of the quarterfinal matches was replayed. It was replayed because all 3 robots on our alliance lost communication with FMS for between 6 and 10 seconds, at the same time. This caused team 226's arm to reset and become unusable for the remainder of the match. I verified the issue by pulling the driver station logs for both teams after the match and comparing the times - both sync up perfectly with the loss of communication. I didn't dig into it any further than that at the time, because the FTA had been informed of the issue and was working hard with FIRST to determine what should happen.

If you can get in touch with your alliance partners and get their logs, you may find a correlation in communication events. There seemed to be a number of gremlins, including the 'you most close and reopen the driver station' between each match or FMS can't see you.