Soccer Simulation Demo 2022 - Do you want to participate?

After quite a successful trial run of the Demo competition this year (Soccer Simulation Demo 2021 - Do you want to participate?), we’d like to see if there is interest in doing something similar in the upcoming one.

The setup will be quite similar – we’ll still use Webots and the robots will be programmed in Python – but the code of the simulator will most probably change a bit, so that the matches are at least a bit closer to what the RoboCuJunior Soccer looks like in the real world (i.e. it’ll be close to the Lightweight league). You can see a sneak peak of what it may look like in the end at How to program your robot - RCJ Soccer Sim

Although no dates have been set yet, we tentatively plan this event for January 2022 and as always, we are inviting all RCJ Soccer teams with members under the RCJ age limit around the world to participate!

Do let us know if you plan to join us in the form below – it will have direct impact on whether we’d actually do it (you know how it is…).

As always, should you have any questions, please do not hesitate to send them here to this forum thread.

We hope to see you (and your code!) at the event! :slight_smile:

Hi @mareksuppa !

May I have a few questions?

  1. Shall this competition still be in “Demo” status, or will it be an “Official” competition?
  2. Can members of the Simulation team also participate in either a Soccer Open or a Soccer Lightweight team?
  3. Will the Soccer Simulation Demo Competition 2021 final’s source codes from the teams be shared?

Thank you,

Hi @rlaszlo ,

Sure, let me respond inline:

This will still be a Demo competition, one in which we’ll try out the simulator’s environment that we would most probably use in the Summer, should the situation warrant it.

Absolutely, this being a Demo competition, we do not have any specific limits with regards to the other leagues.

There are no concrete plans for that yet but since sharing is very much part of the culture around RoboCupJunior competitions, I do think we would lean towards sharing it.

Hope this helps!

– Marek

I would say we will not share demo source codes before the actual RCJ championship in July (of course if SoccerSim league will be part of the competition), similarly to last year.

I can only second @adrianmatejov’s view – the source code would only get released well after this year’s competition finishes.

Hello @mareksuppa ,

We are Team Reset from Taiwan.

We are wondering that as there are more limits added to the robot (robots are no longer able to get the coordinate of the ball) if there is a possibility to add an arc at the front of the robot (like in the physical competition) so that robots are able to manipulate the ball more and if additional sensors like a distance sensor can be added.

Thank you!

Team Reset

Hi @thomastseng0380,

…if additional sensors like a distance sensor can be added.

Currently, all robots are equipped with GPS sensor, which basically provides the exact coordinates like you would read before from supervisor - that’s why the distance sensor is not necessary.
We have tried to experiment with Lidar sensor but unfortunately, it decreases Webots performance significantly and it is not possible to run the simulation in fast mode (at least on my computer). However, we might experiment with Distance sensors of type “sonar” and “laser”. If such sensor works, we will consider changing GPS with distance sensors.

…if there is a possibility to add an arc at the front of the robot

This year we focused mainly on implementing sensors, so the shape of the robots stayed the same. But your suggestion seems reasonable. Have you experimented with the arc (or generally the shape) in Webots? If you have some design ready, feel free to notify us here or directly at GitHub.


Hello @adrianmatejov ,

Thank you for the reply. We will try to look into designing a robot with an arc in Webots if we have time before the demo competition and tell you how it goes on this forum (if we do end up working on it).

Additionally, we would also like to ask whether there is a possibility for teams to know the locations of their opponent’s robots. After experimenting with this year’s new rules, it seems as though there are certain limits with the IR sensors that make it pretty difficult for robots to detect the ball (if a robot’s angle to the ball is blocked, it would completely not be able to see the ball). Without having additional distance sensors (in addition to the GPS sensor) or the ability to know the opponent’s location, when the opponent’s robots cover the ball, the ball would completely go undetected. This would make it even more difficult for robots to detect the ball compared to the physical leagues as robots are typically able to detect the IR ball in Lightweight and extra sensors can be used to somewhat get the location or proximity of the opponent’s robots in Open League (if in the case that the ball is covered or blocked).

We highly suggest making it slightly “easier” for robots to detect the ball. However, if there is no way for additional sensors to be added or the location of the opponent’s robots to be known, that is still fine as it would be an interesting challenge for teams.

Finally, as we have begun to prepare for the demo competition, we would like to know whether or not the demo competition is going to happen (or if you foresee the demo competition happening) and if so, around what week or day of January the demo competition would happen.

Thank you!

Team Reset


I’ll try to implement the sonar/laser distance sensors and see if that works in terms of performance. Will let you know about the result of my experiments.

Thanks for your great contributions! We really appreciate it.

The demo competition will most probably happen during the beginning of the next year. We haven’t set the exact dates yet, but will certainly announce it in advance.


Hello @adrianmatejov ,

Again, thank you for the reply.

As we would like to try to experiment with the arc and the shape of the robot, are there any hardware restrictions that we should be aware of? These hardware restrictions can include the number of motors that we are allowed to implement and the positioning of those motors.

Additionally, if a design was to be made, how should we send it?

Thank you!

Team Reset

Hi @thomastseng0380,

we currently do not have any strict restrictions. You can even try to model rounded (cylindrical) robot with 3 or 4 motors if that works.

You can submit the soccer world file for example by opening the pull request in rcj-soccer-sim github repository.


Hello everyone,

We have created a draft for distance sensors. Feel free to check it out at our github page
You can find some docs at

Let us know about anything that you encounter (bugs, suggestions for improvements) while testing that. Thanks.


@thomastseng0380, I’m just curious, have you managed to experiment with the arc / shape of the robot? If so, do not hesitate to let us know about the results. Thanks :slight_smile:


Hello @adrianmatejov,

Sorry, we have not completed a new design yet and are still trying to test things out (as we have mainly been preparing for the Demo Competition lately). If we do end up coming up with something, we will inform you on this forum immediately.

Additionally, is there a predicted date for when the Demo Competition will happen?

Thank you!

Team Reset

Hello, no worries :slight_smile:

Demo competition deadline will be around 15th of February, the exact date has not been decided yet.


I had some questions about competitions
1- Will the teams receive a quota for the RoboCup World Cup if they win this match?
2- What are the quotas for Iranian teams?

Hi @Kevin2000,

As the name suggests, this Demo competition is essentially a demo of the competition that we plan to hold later in the year, close to the World Cup that will take place in July. Hence, these are completely different competitions – the World Cup will have a separate qualification process.

Hope this helps!

– Marek

Hello, I am Horiuchi from Japan.
When will the soccer simulation 2022 be held?
Please tell me.

Hello @Horiuchi,

yes, but it is not part of the official RCJ event. See this topic SoccerSim World Championship 2022 for more information.


1 Like