Chief Delphi - The communication tides are shifting...

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Re: The communication tides are shifting...

Quote:

Originally Posted by Danny Diaz (Post 1166578)

I have one compare that is comparable - BEST. I have been a coach for BEST Robotics for the past 9 years, and BEST recently (last 2 years) moved to the VEX control system. I have been nothing but disappointed by the VEX system used in BEST. Our robots have had many "communication issues" stemming from random drop-outs to random reboots (all while using the default code), and at least 3 tournaments here in Texas had to go to using tethers because the wireless just could not be trusted - when teams play 8 rounds and have a combined connection time of less than a minute, there's something bad wrong.

I'm not here to blast the VEX system, I'm just here to say it's not the bastion of hope everyone is looking for.

-Danny

Let me put on my "day job" hat. :)
Speaking as the Director of Product Development for VEX Robotics, Inc...
We have been informed that certain BEST hubs had some issues, and are working closely with folks at BEST Robotics, Inc. to improve their customer experience, specifically through education of folks on how to troubleshoot the system.

Danny -- I'd like to think you and me "go way back." I'm not sure exactly what is going on, and I'm wondering why you haven't emailed me already? Have you been in touch with the VEX Support Group? As you should know, we'll work to "make it right." jvn@vexrobotics.com

That said... at VEX World Championship this year (an event with over 600 teams) we played 1,900 tournament matches and over 450+ skills challenge matches with almost no issues.

-John

Re: The communication tides are shifting...

Quote:

Originally Posted by mathking (Post 1164972)

If VEX competitions had 140-150 pound robots racing around at the rate of speed of FRC robots, they would need a more complex field management system to insure the safety of the people and field. And it might well be prone to significantly more problems.

Please explain this quote a bit more. Why does it need to be more complex for it to be robust and safe? Isn't the opposite usually true? Besides, I believe the VEX TMS is already more powerful than the FRC FMS, while also being more stable, easier to use, and less problematic. VEX Worlds ran 1900+ matches and 650+ skills matches without a single problem attributable to VEX TMS.

Quote:

Originally Posted by MAldridge

All in all, we are dealing with a very robust system. The only part of it that is not robust is the FMS program itself. To me, the only solution is to scrap the current VB.NET program entirely, and rewrite it from the ground up in a more sensible language like LabVIEW.

Quote:

Originally Posted by MAldridge

As for a sensible language, I base sensible of of what the guy running it can debug. Since most FTA's do labview, it is sensible that they could troubleshoot it. Also, since the rest of the system is already written in labview, it makes sense to have it all done in one language.

I still don't get this. You define a sensible language as one that an FTA can debug in real time? You honestly want FTAs to dig into labview code during an event? If the problem gets that far, the process to develop a robust FMS has failed big time. I define a sensible language as one that allows the developers to meet the usability & performance requirements of the event, nothing more.

Re: The communication tides are shifting...

Quote:

Originally Posted by MAldridge (Post 1164155)

All in all, we are dealing with a very robust system. The only part of it that is not robust is the FMS program itself.

Even ignoring the still-mysterious loss of control experienced by a number of robots, I think the multiple issues that have been traced to the D-Link wireless bridge contradict any description of the system as "very robust".

Re: The communication tides are shifting...

Quote:

Failsafe systems are rarely simple in implementation. The field management system has to be able to shut down robots, no matter what else goes wrong. From my experience in FRC since 1999, the first purpose of the whole control system is to make sure the robots shut down when they are supposed to shut down.

I can't speak to the VEX world championships, not having been there. But I have seen communications problems at the competitions I have been to. Not as many as at FRC competitions. But I have seen robots not shut down when they were supposed to. And again, I am not bashing VEX. I love the VEX system, and have a bunch of kits in my classroom.

Re: The communication tides are shifting...

I think we may be throwing too much technology at the FMS and hence introducing to much opportunity for bugs to creep in. At the off season scrimmages in Oregon we decided to NOT USE AN FMS because of all the problems. Each team's laptop uses a 802.11n USB dongle (or built-in 5Ghz support) to communicate directly with their robot. The philosophy is if it works in your lab, it will work on the field. Our matches at Girl's Generation and BunnyBots go off without a hitch. If a robot isn't communicating it's the team's problem. There's no mysterious "FMS" that people can point fingers at. The wireless adapters in the 5Ghz band seem to have no problem working out what channel to use and many robots last season were streaming high quality video. You also don't have to set the key on your radios at the event.

In a FIRST competition environment we could do the same thing but have a USB plug for the field to communicate with the driver's stations. That would be how you would disable a robot, how you'd start the match, switch from hybrid to teleop, etc. That USB plug could look like a keyboard to the laptop so you'd have keystrokes for all those things.

While we know this works at a regional with a single field I don't know if it can work at the Championships. We always have the on-deck teams turn on and connect to their robot while waiting to play. That means you'd have 48 teams connecting at the same time in the dome. They won't all be driving so it might be fine.

Anyway, I'd vote for keeping it simple.