What to do when your robot loses Comms

[Jaci]

There's been a lot of cases of "My robot keeps resetting comms during a match" this year. Whether it's faulty wires, faulty components or just bad luck, it seems to be much more common this year than any other, so let's talk about what to do if (and in some cases, when) this happens to you.

This happened to us many times at the Australian Regional, and as the Driver, this made me pretty upset and my heart sunk. It turns out our circuit breaker was faulty and tripped and reset whenever we hit a defense at full throttle (similar to if you lightly press on the circuit breaker, it will lose power and then get power again without tripping the latch). Other teams have experienced dodgy connections, dodgy radios or FMS not agreeing with their robot.

So, what do you do with the 10-60 seconds you have before your robot comes back online?

Do you stare at it, waiting for it to come back on? No.
Do you look at the logs and try to diagnose the issue? No. The logs will still be there after the match. You can't fix it during the match, so just leave it until you get back to the pits.
Do you have a discussion with FTA about how they're sure its not their problem? No.

Use this time effectively. Look at the robots on the field, both in your alliance and your opposing alliance. Look at what they're doing, and make a plan for what you're going to do once your robot comes back on. Up until the time your match begun, you didn't know what everyone on the opposing alliance was going to do, nor did you know for 100% certainty how the match was going to play out. If you can, relay this information to the drive coaches of your alliance, and if in playoffs, your alliance captain. Use this to coordinate your match to give yourself the best possible chance of winning.

[towersda]

This happened a couple of times at both of our regionals to us and our alliance partners. The common fix for us was to have another robot give the robot that lost comms a good push. surpassingly they came back to life 50/50

[rtfgnow]

Do not put down your controls and think you are out of the match. I have stood by the robot and seen it come back up and then looked at the drivers and they were doing nothing. I try to signal them to start driving the best I can but they don't always realize they have control.

[Jaci]

Do not put down your controls and think you are out of the match. I have stood by the robot and seen it come back up and then looked at the drivers and they were doing nothing. I try to signal them to start driving the best I can but they don't always realize they have control.

This is the main reason I say "if you can, notify your other alliance members". Don't pull your hands off the controls, but use this little period to make a plan for the match. If you want to be super sure, get your drive coach or codriver to tap you on the shoulder when the robot is back up and running, or reverse those roles so the drive coach or codriver watches the other teams and tells you the plan/details as they become available.

[JesseK]

I've done a few things in the 2 matches we sat this year.
Look at any D/S logs for errors. Depending on how you're setup/configured, the errors may be gone by the time the robot makes it back to the pit - especially if COMMS comes back. This may provide crucial info to the pit crew in diagnosing the errors.
"Reboot RoboRIO" sometimes works, but could take as long to come back as there is left in the match
Bring up driver's station performance characteristics (taskmgr, custom stuff, etc)
Use the time to specifically coach the HP on a new strategy/technique for rolling the balls
Keep mashing buttons
Tell the partners, discuss what to do next. Answer their questions about your robot "Can I push you?" etc.

[Jaci]

I've done a few things in the 2 matches we sat this year.
Look at any D/S logs for errors. Depending on how you're setup/configured, the errors may be gone by the time the robot makes it back to the pit - especially if COMMS comes back. This may provide crucial info to the pit crew in diagnosing the errors.
"Reboot RoboRIO" sometimes works, but could take as long to come back as there is left in the match
Bring up driver's station performance characteristics (taskmgr, custom stuff, etc)
Use the time to specifically coach the HP on a new strategy/technique for rolling the balls
Keep mashing buttons
Tell the partners, discuss what to do next. Answer their questions about your robot "Can I push you?" etc.


Driver Station logs are saved with a timestamp, they will always remain until you delete them manually.

Reboot RoboRIO won't work if you don't have comms to the radio (which is almost always the issue due to a power cycle as many teams have pointed out)

Getting an alliance partner to push you over the defense is almost always a bad idea. If you lost power because of an impact (i.e. faulty circuit breaker or wiring), getting a second sudden hit from your alliance isn't going to be good news. Not only that, but it takes time away from what they could be doing, like breaching or shooting.

[dsherw00d]

They can tell if it was a complete power cycle, brown out, or if the radio lost comms. In our case, the radio would reboot. Our's was related to a strand of wire that was shorting when getting hit hard. We put a new radio plug/wire on it and it was fine.

I was also told by the CTA that some barrel power connectors are not as good at others. They had a couple issues where it was this. We also hot glued ours in just to be sure. We did notice the new one was a much tighter fit then the one we were using. We also put foam (noodle rings) on top and bottom of the radio to stop vibration/shifting.

Lastly, they stated that with the rough hits, the small fuses ( yellow I think) on the end of the power distribution board would work themselves out slightly. I would push on them every couple of matches along with all the others just to make sure.

If you can power it on in the pits and bang/wiggle every wire you can access. If you loose comms for roughly 1 minute, it's likely the radio. I think a full reboot of the roborio take longer.

We did have 2 smoking robots at FLR - one looked pretty bad - melted a big bundle of wires.

[JesseK]

Driver Station logs are saved with a timestamp, they will always remain until you delete them manually.

Reboot RoboRIO won't work if you don't have comms to the radio (which is almost always the issue due to a power cycle as many teams have pointed out)

Getting an alliance partner to push you over the defense is almost always a bad idea. If you lost power because of an impact (i.e. faulty circuit breaker or wiring), getting a second sudden hit from your alliance isn't going to be good news. Not only that, but it takes time away from what they could be doing, like breaching or shooting.

Well, then I suppose I shouldn't have replied. I suppose the nuances of why we do what we do are too specific to be generalized into the answer you're looking for.

[hectorcastillo]

http://i.imgur.com/AdiBPrO.jpg?fb

[Sperkowsky]

This year we had a tiny 3/4" stroke cylinder. If you pressed retract and push on the controller at the same time it rapidly moved and caused a lot of noise. So, if we lost comms (never happened in a real match) I would just press them both down and talk until I started to hear it.

[IronicDeadBird]

This year we had a tiny 3/4" stroke cylinder. If you pressed retract and push on the controller at the same time it rapidly moved and caused a lot of noise. So, if we lost comms (never happened in a real match) I would just press them both down and talk until I started to hear it.

That'd be sweet if we could do that with LED feedback.

[hectorcastillo]

That'd be sweet if we could do that with LED feedback.

Isn't that what the signal light is for?

[IronicDeadBird]

Isn't that what the signal light is for?

Yeah the signal light is practical, a suhweet lightshow on comms outage isn't however...
Actually what would be super practical is force feedback on a controller that'd wake the drivers up.

[hectorcastillo]

Yeah the signal light is practical, a suhweet lightshow on comms outage isn't however...
Actually what would be super practical is force feedback on a controller that'd wake the drivers up.

I'm pretty sure xbox controllers have built in vibration. Not sure about Logitech, though. That would be really cool.

[Bryan Herbst]

As someone frequently assisting with robots dropping out on the field, here are some things I wish drivers would not do:


Unplug the ethernet cable to their driver station
Restart the driver station software
Restart the driver station laptop


I understand the frustration. I also know that for most teams, the most immediate feedback available is simply that the driver station can no longer can communicate with their robot.

However, unless you are pretty confident that one of these three things is the problem, doing them makes it much more difficult to diagnose and solve the problem.

The key reason these things hinder troubleshooting is that the FMS cannot talk to your robot if it cannot talk to your driver station. As long as your driver station is rebooting or unplugged, we can't see whether the radio has reconnected, the roboRIO rebooted, or that the field itself is indeed causing a problem.

All too often I see a momentary loss of comms turn into a much more prolonged loss of comms because a team panicked and decided the best course of action was to reboot their laptop or the driver station software.

Instead, take a deep breath. Look at your robot (and the more detailed diagnostics tab on the DS) to determine what the problem is. If your DS can still see the robot's radio, then doing anything on the laptop most certainly won't help. If you can see your radio and see no lights on it, again, you can't do anything from the driver station to fix it.

As a bonus, if you start trying to use the feedback indicators on your robot to help you, you are much more likely to put those indicators (such as the radio and the RSL) where you can actually see them. This in turn makes it much easier for the field staff to see them and help you.

[protoserge]

As a bonus, if you start trying to use the feedback indicators on your robot to help you, you are much more likely to put those indicators (such as the radio and the RSL) where you can actually see them. This in turn makes it much easier for the field staff to see them and help you.

QFT.

The RSL is the first indicator you should at. Learn how to read it. If you see FTA(A)s looking at your robot, that is where the problem is. If the FTA(A) comes to you first, it is your driver station.

[plnyyanks]

As a bonus, if you start trying to use the feedback indicators on your robot to help you, you are much more likely to put those indicators (such as the radio and the RSL) where you can actually see them. This in turn makes it much easier for the field staff to see them and help you.

So much this. There were so many times this year when I'd see a robot drop communication, but the radio/roboRIO were hidden deep in the robot such that you couldn't see any of the status lights. The most I can do to help in that situation is shrug and look at it after the match (which is less helpful than being able to watch the lights while the issue is occurring). This seemed be a larger problem this year with the smaller radio and smaller robots, where the electronics were crammed in anywhere they could fit.

[Sperkowsky]

I'm pretty sure xbox controllers have built in vibration. Not sure about Logitech, though. That would be really cool.
We have used the Xbox controller vibration but found its a little Finneky and behaves differently from a test Match to a real match. (we tried to make the controller vibrate during the last 20s). In the end we did use the vibration motors for fun when you pressed the shooter wheel button.

[Mark McLeod]

One thing I tell drivers when some component of their robot reboots during a match is to take it easy on the driving when it finally comes back.
If the robot has already died once from loose wires or poor power, then drive more gently, don't jam on the controls as soon as it comes back up.