Originally Posted by Dave Flowerday (Post 941969)

It appears the FMS does not properly measure time during the matches. It seems to add about 5 seconds to each 2-minute match. I noticed this while watching a webcast of the Milwaukee Regional and doing some timing measurements for something unrelated on my computer, and confirmed it while I was at the Midwest Regional this past weekend (to make sure it wasn't somehow related to the webcast).

I don't really think this is a big deal or anything; it's more of an interesting curiosity. However, I wonder how many matches teams have lost due to something that occurred in the last 5 seconds when the match should have been over? I'm pretty sure this has happened to us more than once. It's a little irritating to think that we may have won some of those matches if FIRST had followed their own rules... ;) (I know, we've probably won some in those last 5 seconds too so it probably evens out...)

Originally Posted by Joe Johnson (Post 941976)

Anyone have a more elegant solution?

Joe J.

Originally Posted by Joe Johnson (Post 941976)

This is interesting. Does this happen every time or does it happen only occasionally.

Originally Posted by Dave Flowerday (Post 941988)

It seems to happen every time. I checked a few matches live during Midwest and Milwaukee, and confirmed it at other events by spot-checking a selection of videos from TBA. You can check yourself by going to TBA and selecting a random match video - just take note of the time in the playback bar when you hear the 3 bells to begin operator control and then fast-forward 2 minutes. In every video I've checked, I've found that exactly 2 minutes later you'll hear the announcer saying "5 seconds left!" I just checked and it appears (based on more TBA video) that this bug was introduced between the 2008 and 2009 seasons.

I wondered if anyone was doing anything like that with timers that would run the length of the match... obviously for anyone trying that this bug is a little more serious. I can't think of any easy way off the top of my head to know how much time is remaining in the match other than what you're doing, so yes, I guess you'd have to wait until 1:22... (think of the upside though - maybe this means we can all be 5 pounds overweight!)

Originally Posted by Joe Johnson (Post 941976)

This is interesting. Does this happen every time or does it happen only occasionally.

The reason I asked is that I have just asked our coders to implement an automatic brake feature that puts the brake on our winch with 3 seconds left - I don't like depending on our drivers to remember in the heat of battle if it is easily fixed. From what our coders have been able to discover, there is no "what is the match time" function available on the cRio -- on the Classmate, yes, but not the cRio. So... no problem. We can watch for the first enable after Auton Mode and start counting seconds. When we get to 117, time to throw the brake with 3 seconds to spare...

...except now do we have to wait until 122?

Hmmm...

Anyone have a more elegant solution?

Joe J.

Originally Posted by Greg Marra (Post 942295)

This is very interesting. I will time some matches during the Boston Regional to confirm this "on the ground". Watching recorded matches may introduce issues with different frame rates due to re-encoding, but it sounds persistent.

Originally Posted by David Brinza (Post 942354)

From Dave Flowerday's post, he timed matches in-person at the Midwest Regional, confirming his observations from the Milwaukee webcast. From the perspective of fairness, if all the matches run the same duration, no advantage is gained or lost* by any teams.

Maybe FIRST will discover a mini-black hole in the FMS that dilates time and create other problems with the field? :p

*Unless, of course, you don't trust your drivers and have automatic timing features in your code that effectively ends your match earlier than the rest of the field. (Sorry, Joe!)

Originally Posted by JVN (Post 941987)

Make your driver do 100 pushups every time he forgets.

-John

Originally Posted by David Brinza (Post 942354)

Maybe FIRST will discover a mini-black hole in the FMS that dilates time and create other problems with the field? :p

Originally Posted by Rob (Post 942432)

<snip>
I wonder how the FMS calculates time...(not a programmer so that may be a rhetorical question...)

Rob

Originally Posted by Tom Bottiglieri (Post 942300)

Is this a bug that should get squashed before this year is up? I know the obvious answer is yes, but technically it would be unfair to teams playing in later weeks.. ;)