Ball speed testing after matches
 

At the Portland Regional on more than one occasion the head referee announced that a robot was going to have the ball speed checked after a match had been completed. Did this happen at other regionals? I never heard if the speed was excessive or if a score was changed.

Ken

PS Steve and Glenn, we stopped by the 254 pit and were told you are not working with them this year. I hope you are both involved with other teams. FIRST needs both of you.

Re: Ball speed testing after matches
 

At New Jersey this happened on 3 occasions that I can remember, 25, 293, 303 all were tested on Friday some time. 25 and 303 both were shooting around 11.7 m/s and 293 set the new land speed record at a whooping 15.7 m/s which they later turned down to about 11.5 m/s

The test unit consists of 2 light sensors that are spaced 1 meter apart and are connected to a computer where the time intervals were captured and then the speed calculated. The unit itself is then held right at the exit point of the ball. The only teams that tested were the ones that the ref's felt may be shooting at an excessive speed.

Re: Ball speed testing after matches
 

Those three tests you speak of happened late Thursday night. We werent in question, but just out of curiousity, we decided to check it. The head ref said we were never in question at any point. I know the bots they had checked after matches on thursday, three of them, were all clocked too fast, and all had to slow down their system.

Re: Ball speed testing after matches
 

At the VCU Regional, I know team 435, Robodogs, were speed tested at least once. I stood 20 feet away as a tape measure was laid out and their robot was tilted forward at an angle and test fired. There did not appear to be any problems found. I believe it was done on day 2 of competition and the procedure took at least 20 minutes. Their robot design is excellent and a pleasure to watch. :)

Re: Ball speed testing after matches
 

I have a really stupid question... and yes, I know some of this goes on GP, but how are they really going to know how fast a ball is going during a match if they test the robot after?

For example, our shooter at full speed can shoot nearly 65 feet. We are trimming it down in software so that it only goes the 12m/s or 35ish feet... but what prevents us or any other team with that capability from modifying our code or using some button to "show" the judges it only goes a certain distance? On top of that, our shooter has variable speed controlled by the driver, so our intention is to have max variation at 12m/s, but how are the refs going to know if we are at max speed or above?

My guess is the whole answer is GP... but I know a lot of teams, it might just be ignorance... many teams probably never really got to test the real speed of their shooter... distance would be the only predictor.

And dont get me wrong, we are going to do everything possible to make sure we are under the 12m/s, but it just seems if our team has the capability, what prevents any of us from doing it intentionally or unintentionally?

To me... other than for safety reasons, it seems like this is a really really difficult rule to enforce.

Re: Ball speed testing after matches
 

It is. Its almost impossible to enforce, or it seemed like it at points. That might just be me though. How can one accurately tell from eyeballing if something is relatively close to 12m/s. Sure, you might be able to tell if something is going insanely fast, but its very difficult to actually say for certain that yes, that robot is violating the speed rule. And its possible that it will be left up to the decision of the referees whether to call somebody for violating the speed rule or not.

Re: Ball speed testing after matches
 

Well, if your shooting it 65 fps, you'll be hitting shots from about 3/4 court, which might be a tip off :yikes: :p
But otherwise, yeah, it's an issure of GP and honesty.

Re: Ball speed testing after matches
 

well alot of this is all on GP but there are some ways to tell. The distance away from the goal, the height of the ball, the trajectory (flat or parabolic), etc. Once you have seen something shoot at proper speed it becomes instantly apparent if you are over speed.

Re: Ball speed testing after matches
 

Wow, I'm blushing, thanks for the compliment. Our robot was actually tested twice. The first time it was tested while sitting level and we passed the test, but then we were contested a second time because we shoot at a 60 degree angle rather than 30 degrees, so they placed us on a 30 degree slope to fire and we came in about a foot under the maximum distance. It was really more an optical illusion with our robot, because our flywheel maintained the momentum we could rapid fire a continuous stream of balls.

Re: Ball speed testing after matches
 

At the portland Regional, our robot was tested for 'shooting' velocity(we scored about 30 points in one dump, on the low goal). Turned out we rolled balls out at 1.2 m/s -_-

Re: Ball speed testing after matches
 

A ball speedometer will be available at each regional in the future. It will take the guess work out of shooting for distance. As many teams have already figured out, back spin on these balls cause the trajectory to flatten out. If you are unsure of your ball speed and are prepared to trim the speed down to specification, you will have the chance with the speedometer.

Re: Ball speed testing after matches
 

This is true enough, and it was obvious in some cases. But when the speed was close it was difficult to tell if they were a smidge over or not. And yes, in a lot of cases it was possible to tell when the robot was over. And some were caught because their shots were obviously travelling too far for the angle shot at etc. There was one at PNW that was only .6-.8 M over. And while it was possible to tell, I must admit it was much much harder to see.

Re: Ball speed testing after matches
 

Somebody asked us to be tested after our first match. The funny thing is we had only passed the speed test right before that match. We shot 11.5 both times.

Re: Ball speed testing after matches
 

I manned the speed trap at Florida for a few hours, testing the teams as the refs asked. Two teams that I tested had a little too much pepper on their shots, but it was fixed pretty quickly.

The speed trap itself is a little clumsy to use, mainly due to the length (a smidge under a meter) between the two photogates. I think we had to test 233 about fifteen times because we couldn't get a reading without balls whacking the exit of the chute. :ahh:

Re: Ball speed testing after matches
 

At FLR they pretty much tested everyone it seemed, I know we were tested twice already at 11.27m/s so it would have been nice if they made the plans available for teams to build the same measuring device that they are being checked with earlier so to avoid the unncecesary guesses and tension during practice / inspection day.

Just my 2 cents to make things more efficient.

Ellery