Re: Field Static Solutions
 

Kyle,
The FTA was handling the spray. Is it possible it was done without your knowledge?

Re: Field Static Solutions
 

Don't forget that the weather is changing too. Our team has had major static issues with robots in the past (2003 was the worst), but they always cleared up in the first couple weeks of regionals as the weather got warmer and humidity increased.

Re: Field Static Solutions
 

I am 100% sure that our Static Guard spray never left crate #8.

Also, our field was over a basketball court, not an ice rink.

Re: Field Static Solutions
 

Here at the CT Regional, we have gone through 2 DS....but only when tethered. We feel we are discharging through the ethernet cable because there is no common ground. Once was when we were on the practice field....we were running our ball collector for a while, then went to move on the Regolith. At that point, comms dropped. A replacement DS was able to work. The second time was in our pit. We were running the ball-collector on the cart for a considerable period of time when comms failed again. Again, a replacement DS worked. We are trying grounding connectors between the DS and the robot. Our cRio itself is mounted on our wood chassis.

Any other thoughts out there?

Re: Field Static Solutions
 

At SBPLI today we had only one apparent ESD incident where a cRIO rebooted itself. Staticide has been applied since to the robot and there hasn't been a recurrence.
No DS's have failed on the field during a match due to ESD.

Spare Parts here has been busy with a lot of DS failures though (maybe ten), some due to physical ethernet port damage, but several I'd attribute to damage from ESD. Some may be repairable with a software reload, but I haven't had time to look at them.
Several DS's were dead when the team arrived and hooked up to the field for their next match. We swapped them out before the match started and haven't had a single robot forced to sit out a match.

We have not been wetting the carpet here, however, this is Long Island and it's normally humid. The weather, although cold in the mornings, has been warming during the day.

Re: Field Static Solutions
 

In the LV regional they told us to ground ourselves onto the aluminum before touching the DS or the cables. I have not heard of any DS's dieing here, although we may have gotten lucky.

Re: Field Static Solutions
 

The FTA for the Los Angeles applied Staticide to the entire field (regolith included). There was no perceptible change in the traction for the robots (as compared to what I witnessed in San Diego and OKC).

Al Skierkiewicz' comment above about regolith being a good insulator is true. When treated with Staticide , the trace amount of ammonium salt left on regolith surface provides a leakage path for the charge. The charge can now bleed from the robot, into the trailer, down the chain, onto the regolith surface where it is dissipated across the floor to the carpet, field boundary and finally, earth ground.

Re: Field Static Solutions
 

Solid grounding in multiple points might create other problems due to ground loops. You can get large currents flowing through low impedance paths that can create undesirable results. I think that bleed resistors (1-10 MOhm) within the robot will help avoid differential charging between the electronics and the chassis. FIRST is not recommending this practice until a better understanding of the problem and mitigation is reached.

Re: Field Static Solutions
 

I was FTAA in Connecticut this weekend. Well, there were some issues in Connecticut, but not with the FRP on the field. The chains seem to have done the trick. What was noticed is that driver stations, particularly made with FRP, or lexan were causing the most problems, We were spraying the carpet @ the drivers stations. Theory has it the while walking up to the station, the DR platforms were rubbing against the team member in charge of hooking it up. This created static in the FRP or lexan. When the power or ethernet cable were installed without prior grounding of the the human, the static was discharged from the FRP into the cable. We went through a few DS units.

Please ground yourselves to the driver station framework prior to touching either the cables, or the DS unit.