Robot control cuts out

We noticed as we have been practicing that every so often, usually when were pushing our cim motors to the max, the control to the robot cuts out and were stuck for a couple seconds.

Someone mentioned it could be a programming bug or something, but has anyone else had this??

(were using all 5 cims)

We were experiencing this today during some driving practice with a few other teams today in Quincy, Mass. What it ended up being was nothing more than wireless interference, as soon as we changed our wireless channel the cims stopped cutting out. Could this be happening to you?

don’t know how to change the channel, but it was just us driving, no other teams.

If you’ve been driving it a long time, it’s possible that your battery has worn out.

I believe I heard somewhere that the cRIO cuts off all outputs when the voltage supplied to it drops below a certain value.

You can test this by looking at the battery indicator on the DS while driving the robot. If the voltage tends to fall down to 9 volts or less when running full steam, then it’s probably time to change the battery.

How long does control cut out for? Are you using a fully charged battery?

It may be that when you are powering all your CIMs, the cRIO power drops below the cutoff and power cycles.

Where do you have your wireless bridge’s power plugged into? Does it match the Power distribution diagram?

What do the lights on the speed controllers do before, during, and after this happens?

Is your wireless bridge securely connected to it’s dedicated power source on the PDB, as stated above?

When the robot stops moving, does the Driver Station maintain communications with the robot?


All through build, our Robot WIFI has been bothered by other wireless networks causing interruptions/interference around our campus. It really seems to affect the DS. When we’ve lost communications, all system devices except the DS are pingable (is that a word) from another PC. We didn’t have any noticeable effects last year when the DS was hardwired, the only configuration that has changed from 2009.

I’m fairly sure that’s correct, as we had one of our batteries dip very low and the robot simply ceased to move at all. Other than that, I have no solutions, sorry :frowning:

…you could also be tripping the breakers…?
I would look into that…and I am surprised that I was the first to mention it lol

when our controlls cut out due to power drain, it only shuts out for about half a second…

we too are using all 5 cims…
sometimes when pushing full force, the orange light on top of the robot turns completely off haha
I am concerned about power this year.
Nobody really saw how the CRIO and the power distribution took to the harsh world of high current draw…last year we were all sliding around simply spinning the wheels haha

The Crio has a voltage brownout mode where all outputs are disabled. This occurs when the battery is about 5.5 volts and it sensed through the jumper you must add to the analog module in slot 1. This is performed in anticipation of the battery falling to the point at which the 24 volt power supply becomes unstable. Should the battery voltage fall below 4.5 volts the Crio may reboot.

We had fresh batteries, everything is wired right (as far as I know), and it dosent say were loosing comms or watchdog.

What type of motor controllers are you using?

If you are using Jaguars, when you pull more then 60 amps for more then 2 seconds, it disables the motor for ~3 seconds.

If you are running on CAN, you can set the time for fault conditions down to about half a second.
Which is a little better for your drivers,
(Just imagine them shouting about how they would lose control for some period of time).

I’m surprised you’re the first to mention it too.

If the robot is cutting out when you’re pushing, stalling, or near stalling any of the cims, it wouldn’t surprised me if you’re tripping your auto-resetting (3 seconds) breakers, or that you are tripping the internal protection if you are using jags.

If you’re dumping low enough to cause the Crio to reboot, it’s going to take quite a while for it to reset and regain connection. The bridge will take slightly less time, but it will take time.

So next time you are driving, watch your drivers station. When the robot stops, does it reflect a loss of communication (no robot) or a loss of code (no robot code), or does it stay static? That will lead you in the right direction.

If robot communication is not dropped, then I would start considering that you might be pushing the breakers too hard, or your digital sidecar might have the power wired incorrectly.

Is the crio updated to the latest one? Our robot was cutting out for a second here and there until they updated it.

If the snap-action breakers are popping then the 2010 version of the Power Distribution Panel will show a red LED below the Wago connectors that blew (the 2009 PDP does not do this).
P.S. You can test these LEDs by just pulling a breaker from one of your circuits.

A reason to have mounted the PDP where all the LEDs can be seen by the field staff from the sidelines, and something to watch for.