Maze Rules 2023: Rescue kit and blue tiles

Hi there,
two questions:

  1. Is there a reason behind the circumstance, that it is no longer ok for the rescue kits to have a volume of 1cm^3 ? It says in the draft rules that the rescue kits must now each have a size of 1cm in each dimension, which complicates the build at some point, e.g. if we carry 12 rescue kits in a stack we have to use a stack of at least 12cm of height. Just wondering if this is correct in the new rules and if yes, what reason is there behind this decision.
  2. When do we have to stop on the blue tiles or does that matter in any way. Should we stop right in the middle/before we stand with more than 1/2 of the robot on the tile (like we should on the black tiles)?
    Really looking forward for an answer.
    Best regards,
    Leo

Hi @leo1,

Thank you for your questions. Here are the answers:

  1. Carrying and deploying rescue kits should be equally challenging hardware and software problem, both of which are being made way easier by making rescue kits extremely flat which proved to be optimal solution to original restriction (1 cm^3 volume), as it allows easy hardware solution since it can be just a couple of cm tall, as well as a easy software solution since robot won’t “kick” these flat rescue kits away after deploying them.
    However, it is impossible to fit a typical content of real life rescue kit inside such a flat box, let alone a kit supposed to aid a victim of a big disaster. So, yes this is the change we intended to make the challenge more realistic and, hopefully, inspire competitors to come up with new creative solutions to this part of the challenge.

  2. So unlike black tiles, robot is allowed to enter blue tiles. Only thing that matters is that robot stops before doing any sorts of adjustments (and exiting the tile of course). So stopping as soon as it detects blue tile and then performing any actions it likes is ok. Entering a blue tile completely, stopping than performing any movement is ok too. Entering, wiggling around, then stopping will result in LoP. Entering and going straight out without stopping is also LoP.
    So both situations you mentioned in your questions are good.

Hope this answers your questions,

Matej
2023 committee

Hello @Matej

I have a question about your answer

Entering, wiggling around, then stopping will result in LoP.

Why is this LOP?
Which rule says this will be a LOP?
please teach it

Best regards,
MASA

Hi @MASA,

It is something “written between the lines” - once the robot stops it should stay stationary for 5 seconds → then it is allowed to move freely until it exits the tile.
We realized that blue tiles restrictions are not very clearly explained. We are preparing rules supplement (as judge training guideline) that would go more in detail about most of the situations not clearly defined in the rules, especially in this area, which would be too broad to include in the rules themselves.
We plan to publish this supplement in the coming weeks.

Matej
2023 committee

Hello @Matej

thank you reply.
but I don’t understand your explanation.

I’ve seen in this article that a LOP occurs when exiting blue tiles.
https://junior.forum.robocup.org/t/rescue-maze-4-5-1-c-lop-at-blue-tile/2911

Entering, wiggling around, then stopping will result in LoP.

Why does stopping on a blue tile cause a LOP?
A LOP occurs when the robot exits the blue tile, right?

and one more

I have another question for your answer

Only thing that matters is that robot stops before doing any sorts of adjustments (and exiting the tile of course).

If a robot that visits a blue tile rotates before stopping for 5 seconds, will a LOP occur?

for example
Do the following situations cause LOP?
1-1 Robot enters blue tile
1-2 The robot advances to the center of the blue tile
1-3 Robot stops for 5 seconds
1-4 Rotate the robot 90 degrees to the right
1-5 The robot advances to the next tile on the right
I think this is not LOP.

Do the following situations cause LOP?
2-1 Robot enters blue tile
2-2 The robot advances to the center of the blue tile
2-3 Rotate the robot 90 degrees to the right
2-4 Robot stops for 5 seconds
2-5 The robot advances to the next tile on the right
At what point do LOPs occur?

Best regards,
MASA

Hi @MASA,

to your question: “If a robot that visits a blue tile rotates before stopping for 5 seconds, will a LOP occur?”.
Yes, this is LoP. This is to make it easier and clear for judges to know, when to start counting down the 5 seconds. In short, the first time robot stops inside the blue tile (and before making any lateral movement), it has to stay stationary for 5 seconds. After that it can move freely until leaving that blue tile.

So for your examples:

1 your opinion is correct. This is expected behavoiur → no LoP.
2 LoP occurs at 2-3.

Best,
Matej
2023 committee

Hello @Matej

Thank you reply

In short, the first time robot stops inside the blue tile (and before making any lateral movement), it has to stay stationary for 5 seconds. After that it can move freely until leaving that blue tile.

I understand this.

Two things are not clear
Q.1 In what range should the robot that entered the blue tile stop?
Please tell me the range where the robot should stop on the blue tiles.
Q.2 You wrote that LOP occurs when the robot rotates before it stops.
As the robot enters the blue tile, what movements will cause LOP before it stops?

Best regards,
MASA

Hi @MASA,

Q.1 Anywhere inside the tile fine as long as the robot doesn’t visit adjecent tiles before stopping.

Q.2 Movements that will cause LoP once robot visited the blue tile:
a) forward velocity < 0 (moving backwards)
b) forward velocity ~ 0 AND angular velocity != 0 (turning in place)
c) forward velocity ~ 0 AND sideways velocity != 0 (omni/mecanum wheels)

I think these restrictions should cover it all.

Best,
Matej
2023 committee

Hello @Matej

thank you reply.

b) forward velocity ~ 0 AND angular velocity != 0 (turning in place)

Please tell me the meaning of the symbol “~”.

and, your old answer

Entering, wiggling around, then stopping will result in LoP.

Which of a) b) c) is the above situation?

Best regards,
MASA

Hi @MASA,

I used ~ as “close to” or “approximately”.

I assume you are mostly confused by “wiggling”. The movement I had in mind when writing that answer was the following:
A majority of teams stop after moving one tile forward and then proceed to adjust their distance from the walls. This should be done after serving the 5 seconds penalty. Therefore, to move closer/further from the wall teams often perform one of two actions:

  1. if they have mecanum wheels they can just move sideways. This would automatically be LoP due to c).
  2. other teams do short “wiggly” movement forward and then back. In this case, LoP would be called once robot starts moving backwards.

Best,
Matej
2023 committee

Hello @Matej

Thank you reply.

I used ~ as “close to” or “approximately”

I understand.

  1. if they have mecanum wheels they can just move sideways. This would automatically be LoP due to c).
  2. other teams do short “wiggly” movement forward and then back. In this case, LoP would be called once robot starts moving backwards.

It seems difficult for the referee to observe the subtle movements of the robot and judge them as LOP.
If the robot moves back or rotates even just a little bit, LOP will occur, right?

For example, there is a robot that repeats the following actions to maintain a constant distance from the wall as shown in this picture: move forward, stop, rotate a little, move forward, stop, rotate a little.
If this robot enters the blue tile, LOP will occur.

Similarly, there are robots that move while touching the wall. This robot moves in a curved path, stops when it touches the wall, rotate a little, and repeats the process of moving in a curved path. If this robot the blue tile, LOP will also occur too.

these subtle wiggling movements. I am concerned that there may be disputes between the teams (and the audience who watched the game) and the referee regarding the judgment. Would it be possible to have clearer rules that would make the judgment obvious to everyone?

Best regards,
MASA

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Hi @MASA and @leo1,
we discussed this within the committee and decided to completely change how this will work. Official rules are still the same and will be updated, but please disregard my answers in this thread. Please find official ruling in this thread: Maze Rules 2023: official blue tiles expected behaviour clarification

Sorry for the confusion, and I hope our new ruling is clear and easy to understand.

Best,
Matej
2023 committee

Hello @Matej

Thank you reply.
I read the new rules thread. The criteria for blue tiles is now very clear.
Thank you for your efforts. :heart:

Best regards,
MASA

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