[DISCUSSION] Adjusting height limits between Kid and Adult

Rules and Roadmap
1

The aim of this topic is to discuss the different options and ideas relevant to adjusting the height limits between Kid and Adult. A proposal of vote options is shown to give the highlight of how this would be presented to the league. Finally a rudimentary context on the vote is given which can be completed based on the discussion in this forum.

Proposal for vote:

  1. Should we allow a gap between max height for KidSize and min height for AdultSize? Yes/No
  2. If 1, what should be the max height for KidSize? 90/100/110/120/130 cm KidSize only
  3. If 1, what should be the min height for AdultSize? 90/100/110/120/130 cm AdultSize only
  4. If gap is not allowed, what should be the height limit between KidSize and AdultSize? 90/100/110/120/130 cm

Context:

With the merge of TeenSize in KidSize and AdultSize, one of the problem which appeared is the following: On one hand, lowering the minimal height for AdultSize is taking a step back both from a research and from a public point of view. On the other hand, increasing drastically the upper limit for KidSize is problematic for small robots.

Active questions:
In case there is no gap, how to be fair for Q4 given the fact that there are far more teams in KidSize than in AdultSize.

EDIT: Clarifying that it is not a vote, but an open space for discussion.

2

_1. No
_4. 100/110

Ad 1. The size overlap in the previous rules (with teensize) was there intentionally, so that teams could gradually “upgrade” into the bigger size classes. Banning robots of certain size is the worst possible solution.

Ad 4. Either 100 as it’s a natural size barrier (meters instead of centimeters) or 1.1m as thats exactly in the middle of the previous teensize description (80-140)

Regarding:

Context:
With the merge of TeenSize in KidSize and AdultSize, one of the problem which appeared is the following: On one hand, lowering the minimal height for AdultSize is taking a step back both from a research and from a public point of view. On the other hand, increasing drastically the upper limit for KidSize is problematic for small robots.

I don’t really see the reasoning here, you want to be fair to one class, while argumenting it with a step back for the other. We can turn the argument around and say that having larger robots allowed in kidsize is a step forward for kidsize, while having slightly smaller robots in adultsize is a problem for large robots which cannot get up, need to move less mass with the same sized actuators and so on.
What are the exact problems for small robots? Because I cannot see any arguments written apart from “it’s problematic”.

It is always a design decision which constitutes a trade-off. Do you want to have robust robots that dont break when falling down? Build small robots then. Do you want to walk faster, but require more actuating power? Build bigger robots.
Honestly, teensize teams in 2019 were not that fast, they had problems walking without falling in open space, getting up and couldnt kick well, I am pretty sure they would not do better than kidsize teams. These are the exact reasons teensize was removed, therefore it is not an argument.

In any case I see this as an opportunity for kidsize team to literally “grow” and take advantage of the possible size increase to gradually develop larger platforms that can walk faster due to the increased size, which comes with its own difficulties.

Regarding the step back for adultsize: I am pretty sure we will not cut our OP2X robots head off, just to be smaller and have an easier time doing whatever. I am almost sure other teams with existing robots will not modify them as well.

Active questions:
In case there is no gap, how to be fair for Q4 given the fact that there are far more teams in KidSize than in AdultSize.

The number of teams is not an argument. It is fluid, and is a result of the rules. In any case, a gradually growing (year by year) minimum robot height for kidsize should be enforced.

PS: On a side note, I personally find it sad that changes are being made again, without even having evaluated the previous ones for 2020 (due to obvious reasons).

3

I just want to elaborate on this point a bit further. Last year, due to the time constraints of making that decision before the Call for Participation is sent out (in the beginning of October), we took the decision on the height update within the TC and without asking the league for their vote on this matter. As it was later pointed out by Sven Behnke and Oskar von Stryk (the Trustee responsible for our league), this decision has potentially major impacts on the scientific progress of the league and should not be taken without asking the league first. Hence, we are opening this discussion topic properly again to take a decision that reflects the opinion of the league better.

And just a reminder for everyone: This is still only the discussion on this topic (and Ludovic proposed the potential voting topics), there is no need to vote on the forum. We will have a proper vote on this later in the fall.

4

Thanks to NimbRoAdult for opening the discussion and thanks Maike for pointing out that this is not an official vote but rather an option to discuss the topic before voting, I updated the initial post to make it more clear.

Regarding the context and the vote options, I mainly extracted what was proposed during the roadmap discussion, this does not reflect my personal opinion and is rather the idea of not starting by influencing the debate based on what I would like to see as an output.

Here, I will give some personal thoughts about this:

  • I understand the concern raised by Sven Behnke and Oskar Von Stryk that reducing the minimal size for adult-size is taking a step-back, not because teams would cut the head of their robots, but because new teams might enter the league with smaller robots. Having slightly above 1m tall robots in the Adult Size would not be positive for the image but also it would reduce the requirements of working with real-scale robots. Therefore I’m inclined to keep a high minimal height in AdultSize.
  • I do understand that the risk of damage for small robots when playing against robot more than twice their size is huge. However I think that it is already an existing problem and that it’s the design choice which matters most. If it gives an incentive for KidSize team to build taller robot, I am perfectly fine with it, as long as they do not suddenly become forbidden on the league because of a rule change.
  • I am definitely not in favor of having rules which ban robots of a certain size (although we have it for robots too small for KidSize or to tall for AdultSize already). However, if the only available option to avoid this gap is having a height limit which is not desired by either KidSize or AdultSize teams, I still think that this would not be the worst option.

Regarding the number of teams, I think that this is definitely an argument because we just take a majority vote now and opinions are highly correlated with the size class, this would mean that we allow KidSize to impose its rules to AdultSize. That doesn’t sound fair to me at all.

5

NUbots believe that the best way to solve this is to reinstate TeenSize.

If there are issues with having such a large range for KidSize (i.e. larger robots damaging smaller robots, smaller robots not having any chance against competent larger robots), then it would make sense to not have such a large range.

The idea of encouraging teams to grow, or even enforcing it in the rules, could be an issue for new teams trying to get into the league, and for current teams that cannot afford to grow.

The gap is problematic because it further restricts the types of robots allowed, excluding robots which are valid in every way apart from their height. This is relevant if a humanoid robot was not explicitly designed for RoboCup and a team wants to use it in RoboCup.

A gap makes it harder for teams to grow since they are unable to create a larger robot or modify an existing robot and test changes before starting in a new league.

Alternatively, if TeenSize is not an option, we would be open to the maximum for KidSize and minimum for AdultSize increasing to 130cm. We would also be interested in seeing an overlap in the leagues (e.g. KidSize at 135cm maximum) to support our previous point of teams growing.