Feedback on possible changes to camera rules

[david]

Hello everybody,

first off: This is not (yet) an official rule change, just something we were prompted to think about by posts here in the forum (specifically Draft rules for RoboCupJunior Soccer 2022 released - #10 by stiebel) . Should a proposal like this go forward we would try to run it as a technical challenge in 2022 and depending on how it goes maybe include it in the 2023 rules.

Omnivision cameras are no longer significantly expensive (fisheye lenses for smartphones are available at around 15US$ and will fit most camera modules). Therefore we are thinking about dropping the requirement for teams to manufacture their own mirrors to achieve 360° field of view.

At the same time to keep it interesting one idea is to allow 360° for only one of the robots and restrict the other robot to something like 140° horizontal FoV so that there is something to be gained from tactically looking the right direction and/or sending information from the all-seeing robot to the other one.

What do you think?

Allowing of commercially available optical components

• Yes, please allow buying optical components (mirrors, lenses, camera modules with large FoV)
• Don’t care either way
• No, please continue to require teams make mirrors themselves
• Something else (please post your suggestions if you choose this option)

Restriction of one robot to a smaller field of view

• Yes, go ahead, one 360° and one 140° FoV seem like a good idea
• Yes but different: Please choose different fields of view for the robots (please post your suggestion below if you choose this option)
• No, please let us have 360° on both robots
• No, please restrict both robots’ FoV to less than 360°

Any other feedback and/or ideas on this topic or other aspects of the rules are always welcome, we do read all it.

Best regards
David

[ilust]

Hello!

In my opinion 360 FoV optical system is the only one data source that allows robots to navigate on the field and precisely position themselves. Thus if overall FoV (I am not talking about the camera here, because conical mirror gives 360 FoV with almost any camera) for one of the robots will be restricted, robot itself will never be able to detect all objects on field (both goals and ball) simultaneously. And since both goals are crucial for navigation, gameplay will badly suffer from such a restriction.
Communication between robots can not fully replace proper vision system. For example there are often a situation when one of the robots is out of the gameplay. In this case due to the lack of the data robot with restricted FoV automaticly will be in a losing position compared to the opponents.
And finaly talking about communication. I believe that even now good communication between robots and proper tactics using both of them gives huge advantage even with 360 FoVs.

So i think we should not make any restrictions on robots FoVs but give teams more ways to using omnivision systems (by dropping requirement to manufacture own mirrors)

Thanks.

Team DOT.

[david]

@ilust

In my opinion 360 FoV optical system is the only one data source that allows robots to navigate on the field and precisely position themselves.

LIDAR is one alternative, sensor fusion (Kalman filters etc.) are another.
In RoboCup Major SPL Humanoid league the Aldebaran NAO robots have successfully solved the positioning task with a two cameras with a total horizontal FoV of 60.97°.

@ilust

Thus if overall FoV (I am not talking about the camera here, because conical mirror gives 360 FoV with almost any camera) for one of the robots will be restricted, robot itself will never be able to detect all objects on field (both goals and ball) simultaneously.

This is true; it is also why we are proposing this rule: It intruduces some of the challenge humans face in dealing tactically with limited FoV.

@ilust

And since both goals are crucial for navigation,

Using both goals for navigation is the easiest way to get positioning out of a camera but by no means the only way. The NAO SPL teams mentioned above do it reliably with 60° of FoV by using field lines, goal posts and the fact that robots do not teleport (i.e. Kalman filters mostly) and have been getting reliably positioning out of 800MHz and 256MB RAM for 10+ years.

@ilust

gameplay will badly suffer from such a restriction.

Please specify what you mean by “suffer”. If robots cannot immediately go for the ball but need to tactically look around and position themselves first that would in my view be a change to but not a detirioration of gamelay. Generally speaking I (speaking only for myself as a referee here) would welcome changes that devalue high power high speed motors and increase the value of good perception and tactics.

@ilust

Communication between robots can not fully replace proper vision system.

It is not supposed to 100% replace 360° vision, but it can offer some things 360° vision cannot. For example if a robot occludes the FoV of Bot A but Bot B can see what’s happening behind that is something not even 360° Vision on Bot A would afford you opening up tactical advantages for effective communication.

@ilust

For example there are often a situation when one of the robots is out of the gameplay. In this case due to the lack of the data robot with restricted FoV automaticly will be in a losing position compared to the opponents.

While this is true good positioning can be achieved even with limited FoV, just with different methods (mostly Kalman filters) than 360° vision would use. But this advantage would be symmetrical, i.e. the same to all teams so no unfair (dis-)advantage to any team would occur, just the existing advantage of more reliable robots having better chances.

@ilust

And finaly talking about communication. I believe that even now good communication between robots and proper tactics using both of them gives huge advantage even with 360 FoVs.

This is an interesting point, could you go into some more detail on this? We all haven’t built robots in a while and are not up to speed on the details of how communication is being used these days.

@ilust

So i think we should not make any restrictions on robots FoVs but give teams more ways to using omnivision systems (by dropping requirement to manufacture own mirrors)

Dropping the self-made requirement is likely to happen even if FoV restrictions don’t get adopted.

Thank you for your feedback and I’m looking forward to hearing from you on the detail-questions
Best Regards
David

[david]

For completeness I’ll cross-post @stiebel 's response here as well. The WiFi/UWB-topic isn’t strictly about the camera but a couple other remarks are.

@stiebel

Hi david,
I very much appreciate the idea to drop of general camera restrictions.
And my first thought was to drop it at all, but I really love the idea to have two rules.
One robot with no restrictions and the other with a fov of 140° and absolutely no increasing allowed whatsoever would bring an absolutely new task to the game: communication. having one robot “seeing it all” and the other one “seeing in only one direction” would force the teams to build two different robots and to think about communication to pass the information from one robot to the other.
Great idea!
(We could think about dropping the restrictions to bluetooth as well as espnow or other peer2peer wifi as well as UWB could offer some more and interesting features with this now need of transferring data…

[stiebel]

Hello again,
we had the Robocup Junior German Open a few weeks ago and we experienced a new situation: The golf ball is smaller than most omniwheels. The camera - mirror construction mounted on top of most robots could not see the ball, once it was close enough as the mirror could not be mounted high enough to get a better angle.

So if we think about dropping camera restrictions regarding mirrors and lenses, what about dropping any restrictions at all?
We then would see optical orientation with a 360° Camera and a precision-view for ball and goal-direction with a front camera.
And for those who feel the desire to calibrate even more cameras they could use two fish eye cams facing front and back instead of building a 360° mirror…

[Mike]

@stiebel thank you for the info and great visualization. I added it to the committee’s sheet with all the notes we took considering the changes to the camera rules for next season.

[mareksuppa]

Thank you for your suggestion @stiebel!

@stiebel

So if we think about dropping camera restrictions regarding mirrors and lenses, what about dropping any restrictions at all?

There is a standard counterpoint that we normally get to suggestions like this (and let me tell you, there have been quite a few of them internally) is the question of “doesn’t this make RCJ Soccer a money game” to which we usually lack a good answer. Would you happen to have some ideas around that?

Thanks!

[stiebel]

Hi Marek,
I absolutely agree that robocup shall not be a money game.
So let’s face it: the cheapest camera/object-detection is the pixy cam for 70$ (or Euro if you like).
with a 320x200 pixel for detection you are fine to see a golf ball when facing to it.
If you want to have omnivision you need a mirror. Even if you have a good one (for around 100$) you have to see the whole field with both goals and the center of the image is useless as it sees the own robot from the top. There are just to few pixels left to see the golf ball on the other side of the field or just near the robot. So you have to switch to a better camera and a perfect lense. We have a full hd cam with an intel myriad chip and a raspberry pi to achieve this task. It works, but it costs a couple of hundreds of Dollars to do so.
Having one pixy looking up to a self made mirror to see the two goals for orientation and a pixy looking forward to see the ball is far cheaper.
And sure, you can always get better results with better tools, but having more expensive robots does not lead to an instant win.
With every additional camera the hassle to calibrate it increases, so I am sure there will not be a “camera battle” in numbers, but there could be an downsizing of the cameras if there is no need for a 4k image to see all that you want.
When I asked my teams about this issue they they have spontaneously favored a two fisheye solution, one to the front, one to the back, both pixys. That solution would see goals, balls, robots and would cost less then one pixy and one expensive mirror.
Best regards,
Roland

[mareksuppa]

Thanks for sharing your reasoning @stiebel!

[david]

Hello everybody who follows this thread: We have merged the pull request into the current draft rules (see this thread for current 2023 draft). This pull request is still open for discussion, what do you think, are expensive ready made mirrors still a big advantage if multiple cameras and fisheye lenses are also allowed or are they just an expensive way to do the same thing then?

Best Regards
David

[david]

For the sake of compleness let me copy/paste the current state of discussion from the PR to here:

aquahika:

Please describe your change in one or two sentences

Omnidirectional lenses must be designed and manfactured by students.

Please explain why do you think this change should be in the rules

Some of the team designed an omnidirectional lens by themselves but delegated manufacturing to >professional metal processing and polishing companies. The prices in various but around hundreds of >euros or dollars. It’s still not “commercial”, but also not made by students.

My idea is we argue that the omnidirectional lens must be designed and produced including polishing >by students and prohibit outsourcing production to other companies or adults.

[misunderstanding about mirrors and lenses omitted for brevity]

dbscoach (me):

Oh, I see. Do we think there is a serious advantage to be gained by means of expensive mirrors if cheap cameras + fisheye lenses allow having reasonable resolution for much cheaper?

JavadRah:

I think we must change our perspective.
It does not mean that we force the students to polish the mirror themselves.
Everyone relies on a part of the robot according to their requirements, some of them have good electronics, another team for accurate shooting, Another team works on the communication between their two robots, and a team on their mirror. Normally, the student cannot reach all these matters with the limited time he has and only focuses on one or two parts.
This is the feature of RoboCup Junior that allows creativity to grow. Putting extra rules will only kill creativity.
We do not want to force students in the direction we want. We must respect their freedom of action.

dbscoach (me):

@JavadRah Consider this: The current draft of the rules (see 2023 Draft Rules Public Discussion #soccer-rules-2023) contains language permitting multiple cameras, fisheye lenses and any kind of bough optical components. We know for a fact that very good but very expensive ready-made mirrors exist. The question is now wether these will give teams that are able to buy them an unfair advantage over teams that use the new freedoms in vision system components but with less available money. If that is the case we would want to prohibit using these expensive mirrors by way of the changes introduced in this PR. What do you think? Will expensive mirrors be used and will they be so effective as to be an unfair advantage over teams that have only cheaper cameras and fisheye lenses?

[david]

Hi everybody,

in the final rules (out now) we did end up dropping all camera limitations. If teams gain an unfair advantage by buying or getting sponsored with extremely expensive optics we might have to think about restricting that in some way but for 2023 everything goes. We’re excited to see what solutions teams come up with.

Best Regards
David