Vision tetras - can the bot pick up red or blue?

Competition Rules/Strategy
#1

Hi,

This sounds like a daft point but I couldn’t find anywhere in the rules that states that the vision tetra has to be your own alliance colour, when it’s picked up and put on the goal, for it to get you the bonuses during autonomous mode.

It’s just that the camera module can only track one colour at a time so if looking for the green band around a tetra there’s not much stopping the robot picking up a wrong one (unless it looks for red/blue once you reach the tetra). I guess your own ones are nearer so more likely to be spotted but still…

I’m assuming that the vision tetra DOES have to be your own colour. Anyone know for definate if the rules say anything about this?

cheers,
Justyn

p.s. translation: colour=color.

#2

I do believe that the vision tetras are blue and red colors with the green strip on them… So it has to be your own color to get YOU the bonus tetras and points. If you picked up your alliance’s vision tetra and stacked it, you’d be giving them their bonus tetra and 3pts.
If it weren’t this way, they wouldn’t be able to count up the score accurately.

#3

The color(stupid UK spellings with their U’s :stuck_out_tongue: j/k) of the tetra determines who the bonus tetras and the points goto, but whether or not you score the tetra is another story. First off, being able to pick up the tetra across the field before your opponent is questionable if they go for it, so you may end up chasing them around. Secondly, depeding on the speed of your robot, if you do manage to pick it up, will you have enough time left in the 15 seconds to cap.
Also, my team has thought of defensive strategies that could apply by tracking the opponents tetra. With enough speed, especially if the vision tetra is not their sole purpose in the auto phase(say if they take time knocking off the hanging tetras), it MIGHT be possible to beat them to the tetra and push it around the field as to keep them from using it. If they beat you to it, because you are still following it around the field, you should be able to at least nudge up against their robot before they cap(because they are in possession of the green object you are following, you’d follow them), or while they are capping. And depending on the force of this “nudge”(or the number of nudges) you might be able to hold them up for long enough to not allow them to cap during the auto phase.

#4

Hmm I don´t think there´s any rule against this, but I personally don´t see any advantage in doing so. It would be interesting, however, if your team decides on an offensive and not a defensive strategy. I could be wrong, but I think very VERY few teams will be able to do much with vision tetras.

#5

Oi, who invented english first :stuck_out_tongue:

#6

Thanks, but I didn’t really mean I was thinking of an offensive strategy - I don’t WANT the robot to pick up the other team’s tetras.

What I meant was do you still get the points whether the vision tetra is your alliance colour or not. I think the answer is clearly NO (which is good news otherwise the game would make a bit less sense) I was just confused because the rules didn’t seem to state it.

My other point was: won’t the robots, set to track green, pick up the other alliance vision tetras by accident?

I’m surprised that tribotec thinks few teams will be able to get the vision tetras when the camera module tracks them for you, more or less (apart from the problem above). Is it because the module isn’t very good, problems with picking up and stacking tetras autonomously, doing all this in 15 seconds, or just that people won’t be bothered?

Justyn.

p.s. Denman - Americans spell through as thru which makes tons more sense. But we did invent soccer so we rock.

#7

Well, there are only 4 vision tetras on the field, so the only problem you might have is if your opposing alliance doesn’t do autonomous at all. You could just set it to detect the neon green, then if your alliance colour is nearby (depending on what side you’re on, red or blue), then it picks it up, if not, then it ignores it.

p.s. Justyn - We spell it interchangeably, normally ‘thru’ when it’s casual, but it’s ‘through’ when we’re writing formally. Also, what is this game you call ‘soccer’? Are you referring to the game of Football by any chance?
p.p.s. Liverpool FC rocks! :smiley:

#8

Yeah that’d do it - I’m guessing you mean that it takes the coordinates for the green it’s found then looks for red/blue in nearby coordinates to verify whether it is your tetra or not.

But there are other tetras about (on loading stations) and probably other red(/blue) objects, ie. the flashing lights for each robot on your alliance. There is a good chance that the module will pick up those reds(/blues) unless they are different enough from the red(/blue) of the tetra. As far as I know, the camera module can only output one set of coordinates when you tell it to track a colour.

That sounds a bit confusing. What I mean is:

  1. You tell the camera module to track green, which it duly does. Other robots aside, there isn’t any other green in the arena. It returns a coordinate of the centre value of a tetra.
  2. Now you want it to look for red or blue, to see if this coordinate is near the previous one. But there are plenty of these reds and blues about in the form of the tetras on the tetra loading stations, and flashing lights from other robots. You can’t specify a specific area for the module to look in.

The alternative is to go right up to the tetra and see if it is the right colour, but this wastes critical time in your 15-seconds.

Actually, this makes me think of another possible problem, to do with how the module locates colour. It returns the centre value of a box that bounds all the pixels its found of your colour. So if you’re looking for green, won’t it pick up both your alliance’s vision tetras and give a value somewhere in between the two (and thats not even considering the other alliance’s vision tetras)?

Justyn.

p.s. sorry to hear that even the you-ess of aye appends useless letters to otherwise perfectly serviceable words.
p.p.s. didn’t want to say “football” lest it be mistaken for an american pastime of the same name, which involves lots of men who want to play rugby but are too scared and pad themselves up until they look really silly.
p.p.p.s. You been to Britain then nartak?

#9

Thought of semi-solutions to some of my own questions.

  1. If the camera picks up only your own alliance’s tetras it will draw a box around the two of them and return both the centre coords of this box and also the coords of the corners of the box. So your robot can assume that there is a tetra at each edge of this box.

  2. You CAN constrict the camera module’s viewing window and so therefore tell it only to look at the place where you think the tetra is. From here you can both determine whether its your own tetra and more accurately where it is by taking the centre value.

So I think I’m more or less satisfied about the whole vision tetra issue(s). Thanks to all for the help.

Justyn.