Usage of passive ball

Will light weight league allow teams to use the Orange Passive Ball in 2018 game ? -

I believe that LightWeight league is supposed to be something like introduction to robotic soccer for children and therefore replacing IR ball with Passive one would make it very difficult for kids to start. But that’s just my opinion, let’s see what TC thinks about this.

I am referring to the Secondary level teams. I think being Light weight not necessarily mean the kids are less knowledgeable. Kids in light weight can create quite impressive algorithm and mechanical design.

Switching to the passive ball will be great, as they don’t have to invest on an expensive device … almost $100 for just the ball. I have had 2 stopped working.

this will encourage the kids to learning opencv as well. I truly hope the CT will decide to allow the Light Weight or at least the Light Weight - Secondary League to use the passive ball.


There are three main reasons which make it important for teams to know ASAP whether they will use the passive ball or not :

  1. for those who have been doing primary for a few years and moving onto secondary level, it will be good for them to learn additional ball recognition avenue. Using computer vision is awesome learning path for them.

  2. Usually rule is not released until February or March. This will give them very little to learn a new platform and OpenCV concept as national one usually takes place in April.

  3. IR Ball simply is really expensive to replace. As I said, I had 2 stopped working; and back then, it cost over $79 per ball. Manufacturer refused to replace or repair. Even now, they finally dropped to $50, still really a high cost.

Hello @elizabeth.mabrey and @adrianmatejov,

I am very sorry for my late reply here.

The plan (as announced in the Big Changes to the Regional Representatives) is that there will be just two Soccer categories (at the international competition), that is Soccer Lightweight and Soccer Open. Soccer Lightweight will still use the IR ball, Open will play with the orange one.

Let me stress that I do understand your concerns, and your provide very valid reasons for a push for using vision, especially on the secondary level. Since the age requirements of the leagues have been removed, what @adrianmatejov mentioned above is indeed the idea behind the two categories: Lightweight being sort of an introductory league and Open the one being closer to the Major leagues. Given these constraints, at least in the interim period of this year the lightweight category will still need to use the IR ball.

Hope this helps. Please feel free to ask more questions if I missed/confused something. I’ll do my best to respond in a more timely manner next time.

Kind regards,

Thank you for the confirmation. Only the Open League will change to use the orange ball in the coming 2018, correct? I am planning their learning path to ensure the kids will participate the competition for the sake of the learning but not just the competition - the same goal of RCJ.

Thank you again for taking the time out to organize this.

That is indeed the plan. If the Lightweight league was to use the orange passive ball in the coming year’s rules, we would most probably see this as a big change and would have announced it among those.

Thanks, it is always very nice to realize there are people out there who appreciate the work we do here :slight_smile:

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I know that this thread is pretty much over, but I would like to add a little to it. As a “kid” myself, I can confirm that learning opencv at the age of 13 wasn’t that easy, but the reward was huge, thus I absolutely recommend it to everyone. However, on the other hand the league is called lightweight because the weight limit is much much smaller. Adding a microcomputer such as a raspberry pi onto a robot with a power supply (unless a BEC or UBEC is used) and all ads quite some weight to the robot, and teams tend to have a 1 gram reserve. There are numerous solutions to this. One of them is pixy, but pixy basically does everything for you, so you don’t learn anything. Another solution would be using a faster chip, something like an STM32 or ARM. However just designing a schematic for those chips and programming them is tremendously complex. Especially using their USB/Camera interfaces. Also lego users would be absolutely hopeless. Personally, I think that a soccer Open Primary and Secondary should be opened. The primary would still use a passive ball, but some rules could be eased up a little to make entry easier for the younger participants. Either way I think that robocup is an amazing competition and I thank all the organisatior and staff, as well as the participants.


“… Also lego users would be absolutely hopeless. …” Well put Zvono.

In mechanical aspect, creating a competitive soccer bot to do in Lightweight is actually so much more difficult than in OpenWeight; because they try to squeeze controllers + kicker + dribbler are very difficult due to the weight limit.

I fully understand that the “Light” was initially meant for lower grades. Unfortunately, judging by the complexity in software portion, it is no easier than Openweight bot. The greatest disparity seems to be in the cost of the bots between the leagues.

– my 2 cents thought