Draft rules for RoboCupJunior Soccer 2022 released

Hello everyone,

After a bit of a break (the virtual format of the 2021 competition was indeed quite exhausting for everyone) and much later than we’d like to, we are happy to share with you the draft rules for the 2022 competition. You can find the rules on the links below in two formats (the contents are exactly the same):

Let me also comment a bit on why did it take this long for the rules to get published, even in this draft form. As you can imagine, there are various reasons for it:

  • The changes that were previously announced for 2022 didn’t assume a world which fights with a global pandemic.
  • We haven’t played any (official) matches on the international level for the past two years.
  • There is a lot of uncertainty around what the competition is going to look like in 2022.

That all being said, we completely understand the need for the rules to get released with the school year starting (at least in the Northern Hemisphere) meaning by the end of August / early September. In an ideal world, we’d have at least a draft of the new rules very shortly after the international competition finishes and this is indeed a state we are trying to get to. Sadly, we haven’t really been able to do so this year, which is fully my responsibility. Part of it could certainly be chalked up to a need to wind down after organizing the virtual event but it still would not be the first time this has happened, which seems to be hinting at a more systemic problem than just this year’s situation. Figuring out how to do this well will be a priority for most of 2022.

Finally, I would also like to note that the rules are still in a “Draft” state, meaning they might still change, but we don’t expect the changes to be very significant.

As always, if you have any thoughts / questions / comments, please do not hesitate to let me know – I will do my best to react promptly in here.

Thanks!

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Hi Marek, thanks a lot for posting the new rules!
This is the hardest cut I could imagine for 2vs2: 18cm AND golfball.
However, it will be a challenge and we all have some time to prepare…

Stop blaming yourself for not being ready in September,
having draft rules at the very beginning of October is early enough.

I found some “bits an pieces” while reading the rules:
1 “Preface” change soccer 2vs2 ball from “2.5cm” to “1.5 cm” as mentioned later anyway.
2. If a robot is designed to kick the golfball vertically (at least partially), what about the standard game? Is the robot allowed to lift the ball as well? This could be clarified somewhere.
3. It could be a good idea to design a “golf ball - kick power measuring device” as a kicker that is optimized for a golf ball will hit the IR-Ball at a far below center of gravity - point making the standard measuring device to a “random generator”

These suggestions are no rule changes at all, so there is no hurry, but I thought telling you as early as possible could help.

Greetings,
Roland

Hi @stiebel,

Thank you for your reply! Let me address a couple of them inline

That’s a good catch – thank you for spotting it, I’ll make sure we update it.

It is indeed a good question and something we wanted to clarify. We don’t really have much of a clear idea how to best set it up in the rules but at the very least we really do not want the orange (or any other) ball to move outside of the playing field, meaning away from the walled-in area (which includes anything above the 22cm line denoted by the height of the walls).

Yes, you are very much right – we are currently working on a new design that should make this at least somewhat sensible. We’ll try to post a draft of it soon and as always, would appreciate any feedback :slight_smile:

Hi! Since there is still no information about kick power measuring device for golf ball can you tell us how powerful kickers will be allowed? Or at least how they will compare to old kickers in terms of kick power or ball speed?

Thanks,
Team DOT.

Hi @ilust ,

Thank you for your question!

We are working on a new design of the kick power measuring device as we speak. Although the actual constants are still being determined, we expect the ball speed not to go over 1 meter per second.

Hope this helps!

1 Like

Hi mareksuppa!
Thank you for reply, ~1 m/s helps a lot.

Thanks,
Team DOT.

hi has there been any update so far? when will the new design be released. teams need this information to design their robots

If 1meter per second is still the constant, it is easy to use (almost) the same measuring device and just reduce the gap between the plates to 2cm, so that the golf ball can not slip through. However, the “initial step”, the small vertical line is to high for the golf ball.
If the 1m/s stays the constant I can “design” a new device. Give me a day…

get it here : https://github.com/stiebel/bohlebots/tree/main/kicker_measure
You can change anything you want or just use the zip-file to order at the pcb shop of your choice.
But be aware : This is not the office measurement device but only the BohleBots - device.

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Something different:
There is the rule, that the single camera is not allowed to have a commercial lenses with an angle of more then 140 degrees horizontally.
To get omnivision a “normal” team has to prepare mirrors and seeing a golf ball on a self made cone mirror at the other end of the field is near to impossible. So I wonder if we could change rules for 2023+, not 2022:
either : only one camera (with no reglementations about the field of view to give normal teams the chance to buy fish-eye lenses…
or : field of view is max. 140 degrees. It is not allowed to use any mirrors or lenses to increase the filed of view.
Why that?
Well, either it does not make a difference how to get the omnivision as bought one solutions are cheaper than good made ones,
or the challenge is especially not to have omnivison to increase the software skills and creativity to find out where to find the ball with a “human-like” field of view.
What do you think ?
(And again, this is not suggested for 2022, the rules have changed enough…)

Hi!
It’s worth noting that ability to see golf ball across full field is depends on your ball color. We bought balls from 2 different brands, one is much more brighter than other. And our robots can easily detect brighter one, but struggles with darker.

Allowance to use fish eye lenses (while remaining allow to use mirrors) might be good idea to give teams more choice and easier access to omnidirectional viewing systems. Though I don’t see how complete ban of all types of such a systems can improve gameplay.

Hi @mareksuppa! Thanks for your clarification on the 1ms⁻¹ ball speed cap.

We do have a few follow-up questions, namely:

  1. Would the “chip kick” be intended for gameplay, or is it just housed as a separate TC in section 9.3.C?
  2. Building on (1), and given that such a TC exists, we find it unlikely that the intention would be to ban “chip kicking” during gameplay. Noting this scenario, would a 1ms⁻¹ ball speed cap still be feasible, or would there be a change in criterion? Based on our theoretical calculations, the ball seems to only be able to reach a height of 2.55cm at a 45º angle, and 5.10cm at a 90º angle, assuming a maximum 1ms⁻¹ ball velocity. This would defeat the purpose of the “chip kick” and render it rather useless during gameplay.
  3. Furthermore, based on a 1ms⁻¹ ball velocity, the possible horizontal travel of the ball kicked at an angle of 45º would be around 10.2 cm, which would make it impossible to do TC 9.3.C as the distance from the midpoint of the field to the white line of the penalty area is 26.5cm.
  4. Notwithstanding the aforementioned, how might the velocity of the ball be measured?

It would be great if we could get an update soon on the actual ruling for “kicker” power as teams are likely finalising designs for regional competitions, and the impact of “kicker” design and size are rather significant in view of the 18cm robot size cut. Thanks!

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Hi @stiebel ,

These are all good questions – let’s try to spin a discussion on them in a separate thread :slight_smile:

Hi @ilust ,

This is indeed something to keep in mind and also something that the rules have a very hard time regulating. In principle, we could add a sentence stating something like “the ball should be colored in bright orange” but what actually constitutes “bright” and “orange” is still rather subjective.

This will be the case at least for the time being (that is, the 2022 rules), and potentially beyond as well.

Hi @neohaojun ,

As it currently is, the “chip kick” is in a separate section so that it can be easily referred to and perhaps to plant a seed, so as where could the league be headed in the future. It is not “officially” part of the gameplay part of the rules, in the sense that it would be necessary for it to be specifically regulated.

Thank you for these back-of-the-napkin calculations! Would you mind sharing the steps that led you to the results you presented?

In principle, however, you are indeed right that 1 m/s essentially renders the whole idea rather useless. That said, as we currently do not have much experience with matches that would make use of the golf ball, the intention of the rules is to lean on the safe side, even at the expense of “chip kick” not being possible as part of the normal gameplay (at least for now).

Let me assure you that we (the Soccer Committee) have spent a massive amount of time discussing that and finding a solution that would be

  1. Simple to administer
  2. Cheap to build
  3. Accurate enough

seems to be quite a tough challenge. For the time being, it seems we’ll try to utilize a similar kick testing mechanism as was used in the past versions of the rules. We’ll have the final draft soon – I’d be happy to go into details then.

Hope this helps!

Hi.

I read in the draft version of the rules that the voltage will be 9V starting in 2023.
If the purpose of this rule is to reduce the speed of the robot, I think it would be better to include a current limit in the rule instead of a voltage limit. Motor power is proportional to current.
For example, a 10A blade fuse is mandatory for the open class, and a 5A blade fuse is mandatory for the lightweights. (Glass tube fuses should not be allowed to be used because they do not respond well to overcurrent.)
For athletes, replacing batteries is a huge expense. I think it would be better to impose a current limit instead of a voltage change.

Thanks.

2 Likes

Hi @seizo_mori ,

Thank you for your feedback.

We’ve spent quite some time debating this issue within the Committee and our assessment was that if we required something like a mandatory fuse, this simply prevents a large number of newcomers from participating (i.e. thing LEGO or FisherTechnik-based robots). If possible, we’d very much like not to prevent them from competing by default.

That said, we are looking at ways of trying to limit the robot speed in ways that would make it

  1. easy to measure
  2. not difficult to implement in all sorts of robots
  3. possible for the gameplay to be a bit slower but still interesting

While our current thinking does indeed revolve around limiting the voltage but we’d very happily consider other suggestions along the guidlines outlined above – that’s also partially why the note is there :slight_smile:

If you could think of some interesting ideas, please do not hesitate to let us know in – they may easily end up making it to the rules.

Thanks!

One more thing about voltage: It lowers either your torque or your max rpm for motors of same shape, size, weight. This is due to back-emf: With increasing motor speed magnets induce a voltage that counters battery voltage and reduces the voltage effective in creating torque. Therefore with less voltage the same motor produces less stall torque and to get to the same stall torque you have to switch to motors with lower kv that have steeper torque drop-offs with rpm. Look up “back emf” for a better description. This is a step we can take to cut off “stupid fast” agility that is fairly easy to implement for both teams and event organizers. If we see that robots have too much force (i.e. torque) available and that impedes game play a fuse might be a good addition.

@seizo_mori I will bounce off of Marek’s response and bring up some of the concerns about fuses we brought up to see if you (or anyone reading this thread) may have more insights:

  • Battery voltage is a simple test with a voltmeter or at the very least reading a label off of a battery/cells. How can one ensure inspectors are seeing a fuse inline with the main power supply especially if integrated into a printed circuit board with several layers? To avoid modifying standard battery connections, we could ask for the inline fuse to be plugged directly to the positive end of the battery, but that could also cause some teams to struggle to find the appropriate cables/connectors.

  • How can we know that all fuses are the correctly rated/typed? Even if we use standard automotive fuses (which may be available internationally), there may be significant differences in tolerances/types/availability to cause similar issues we found with the field carpet. Asking event organizers to supply fuses could allow for all teams at the event having the same fuse but that may lead teams open to blame “bad fuses” if they are handed out (I’ve seen this back in the day when we used to hand out radio crystals at another robotics competition).

  • Exceptions could be made for kit bots like Lego (which probably have their own circuit protection integrated already) - but how do we keep and maintain a valid list of exceptions to the inline fuse rule with so many different options?

I’m open to having some sort of current limitation, just don’t see a practical way of implementing it just yet.

Hi @Mike

Here are some of my thoughts.

  • Battery voltage is a simple test with a voltmeter or at the very least reading a label off of a battery/cells. How can one ensure inspectors are seeing a fuse inline with the main power supply especially if integrated into a printed circuit board with several layers? To avoid modifying standard battery connections, we could ask for the inline fuse to be plugged directly to the positive end of the battery, but that could also cause some teams to struggle to find the appropriate cables/connectors.

The person in charge of inspecting the car should be able to see that the power does not turn on after removing the fuse. I don’t think it’s necessary to examine the circuit too closely. Even now, even if they put a boost circuit on, there is no way to check it.
(It is the mentor’s job to correct the player’s injustice.)

  • How can we know that all fuses are the correctly rated/typed? Even if we use standard automotive fuses (which may be available internationally), there may be significant differences in tolerances/types/availability to cause similar issues we found with the field carpet. Asking event organizers to supply fuses could allow for all teams at the event having the same fuse but that may lead teams open to blame “bad fuses” if they are handed out (I’ve seen this back in the day when we used to hand out radio crystals at another robotics competition).

I am aware that there are only three different size standards for automotive fuses. They are usually color-coded by current value, so it is good to be able to recognize them at a glance.

It is natural for products to have tolerances, but I don’t know if that is a big problem in robotics competitions. If you can show us the data, I think we can have a better discussion.

I don’t know about the carpet problem, but the mainstream thinking of Japanese teams is to design and build robots to work on any carpet. Is it different in other countries?

If the competition organizers were to distribute fuses, there would be no problem if they distributed multiple fuses to each team.
Fuses and crystal oscillators are not comparable in their effects on robots.

  • Exceptions could be made for kit bots like Lego (which probably have their own circuit protection integrated already) - but how do we keep and maintain a valid list of exceptions to the inline fuse rule with so many different options?

I don’t think there are many robot kits that can’t incorporate a fuse between the battery and the main body. If there is something other than LEGO that applies, why don’t we have each country report it to us ?
The International Committee doesn’t have to look into everything.

Thanks for the opportunity for a good discussion.