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The collision rule will be reworked. If two robots collide with a relative speed of more than 1.5m/s, the faster robot committed a foul.

Topic: Will robots that brush each other get the same penalty as robots who crash head-on?

We will most likely implement the following criterion: “At the moment of collision, the difference of the speed vector is taken and projected onto the line that is defined by the position of both robots. If the length of this projection is greater than 1.5m/s, the faster robot committed a foul.”

The bar above the goal will be removed to provide better vision in the goal.

Only linear shots can be used to score a goal. If the ball height exceeds the robot height between the last contact of an attacker and the crossing of the goal line, the goal will not be scored.

Topic: Regarding the rule change that states that only linear goal shots will be counted, does that mean that curved goal shots (like Op-Amp did) won’t be scored?

No. The term “linear” was intended to mean that the ball has to stay close to the ground, in contrast to chip kicks. It does not mean that the ball has to be kicked in a perfectly straight line.

In recent games there were some teams with really powerful chip kicking devices. In case of a goal_kick the team simply chipkicked the ball (over a distance of 9m!) directly onto the opponets goalie and then the team awarded a corner kick.

Somehow i think that this is not beneficial to having a nice game / match. It simply leads to standard situation after standard situation, which is not good.

Some years ago we had a rule that did not allow chip kicks across the middle line, I think we abbandoned this rule for exchange of the carpeting rule ?

Of course the oppents goalie could just detect that this shot will not lead to a valid goal and simply let the ball go through. But even then its always a risk and furthermore, I think that since the ball passes the goalLine (inside the goal) no carpeting rule for the shoting team applies anyway ?

This change applies to division A only. To provide enough space for 8 (and later on 11) robots, the field size will be increased. There are no final decisions regarding the concrete dimensions, mostly because we don’t know yet how much space the SSL is allowed to allocate. The current plan is to double the size of the field (to 9x12m) while increasing the width of the goal by 20 percent (to 1.20m). The defense area will also be increased by 20 percent in each dimension compared to the smaller field. Division B will still use a 6x9m field.

Topic: Will the field be increased as soon as 2018?

For the division A, yes. The size of the current field will not be sufficient for 16 robots, at least if we want to provide enough space for concepts like zone defense or passes in the run. We are aware of the fact that barely any team will be able to afford a full-size field in their lab. In fact, we may even decide to further increase the field in the future. A lot of teams already use a partial field since the size got increased back in 2014. It’s part of the challenge to develop a system using only a combination of simulation and partial field testing.

Motivation:

• the referee does not have to remember to halt the game during discussions
• the time needed by the automatic ball placement procedure does not influence the net game time
• the net game time is roughly the same for all games

Disadvantages:

• the total game time may vary a lot more

In order to reduce/prevent unsporting behavior, we want to increase the penalty of yellow and red cards.

When one team collects 10 yellow cards throughout the tournament, a red card is issued automatically.
A red card means that you instantly lose the current game.

The yellow card count does not include things like being partially inside your own defense area, obviously.
If you get a red card during the group stage, you don't get any points/goals awarded for this game.
What happens to the yellow card counter after a team is issued a red card is to be decided.

This change applies to both divisions. Even though the field increases quite a bit for division A, the maximum allowed ball speed will be reduced from 8m/s to 6.5m/s.

Currently, it is very common to score goals from large distance, even against strong teams. The reason is that the ball is fast enough to make it through a hole in the defense without the defenders being able to react in time. This is not a bad thing by itself, the defense should just anticipate passes and future attack maneuvers. However, the offense is currently very one-dimensional. It all boils down to finding or forcing a hole in the defense and exploiting it. There is only little advantage gained by being able to bring the ball towards the opponent goal without losing possession or getting marked. By reducing the maximum ball speed, long distance shots are less likely to succeed resulting in a stronger focus on positional play.

The signature high pace of our league will not be affected by this change. First, the viewer will most likely not even notice the difference in shoot speed and second, the high pace is not affected by the speed of the robots or the speed of the ball, but of the frequency of actions (e.g. passes, goal shots).

It was brought up at the committee meeting that, because the SSL rules never actually define a “kick” and rather define all our rules in terms of a robot “touching” the ball, a yellow robot could kick the ball hard against a blue robot’s shell and cause the blue team to be guilty of carpeting due to the ricochet. This may not be easily fixable, but it should be considered.

This change applies to division A only. The intermediate-term goal of the SSL is to be the first league to play 11v11 with actual robots (discounting the simulation leagues). To achieve this goal, division A will play with 8 robots per team by 2018 and with 11 robots by 2019 or 2020.

In the last years, slightly touching the ball twice, without significantly moving it was penalized with a double touch.
From my point of view, the rule should mainly enforce a pass to enhance the gameplay, but not punish inaccurate movement.
I would suggest to define a double touch more precisely, e.g. the ball has to be >50mm away from the touching robot between two intermediate touches.
This has the following advantages:

• More fluent gameplay due to less stoppages, especially for new teams
• An autoreferee can not detect slight touches and would profit from a clear definition of double touch.

The rules currently state: "For both direct and indirect free kicks, the ball must be stationary when the kick is taken and the kicker does not touch the ball a second time until it has touched another robot." (free-kicks.tex:6)

Some aspects of the kick-off need clarification.

First,
all robots are in their own half of the field
Many teams partially cross the center line to pass to another robot. It's not obvious whether such a behavior is even covered by the rules or not. I would suggest to change the rule so that it is not allowed to even touch the center line. However, the team that performs the kickoff should be allowed to move freely inside the center circle.

Second,
the ball is in play when is kicked and moves forward
Does this mean that it is illegal to pass to a robot that is standing in the own half of the field? Or does the move forward part just mean that the ball has been shot? Either way that point should be phrased more clearly.

see #17

If two teams want to collaborate and appear and participate as one, they will now be able to register as a joint team.

Topic: What do you mean with “Joint Teams”?

We want to make it possible to cooperate and use multiple systems within one team. This means that a joint team is explicitly allowed to use multiple forms of strategies and robots within one single team. The team will be treated as one, which means that it will only hand in one TDP and can only get one trophy. The limitations of the Mixed Team Challenge do not apply here.

Topic: Why should people even want to form joint teams?

The idea of allowing joint teams is the result of a lengthy discussion about team collaboration in general. There is interest from some teams in focusing on the AI and multi-agent coordination, rather than building and maintaining a large team of robots. The strategy of forming joint teams will thus allow such teams to compete together in games with up to 11 robots per team. Joint teams may choose to adopt any of a variety of coordination strategies, ranging from the standard command protocol, to mixed AI teams, to a hybrid high-level strategy from one team with low-level control from the other. This is again intended to alleviate the high barrier to entry while simultaneously pushing the state of the art in the league.

The current rules read:

No kind of commercial advertising, whether real or virtual, is permitted on the field of play
and field equipment (including the goal nets and the areas they enclose) from the time the
teams enter the field of play until they have left it at half-time and from the time the teams
re-enter the field of play until the end of the match. In particular, no advertising material of
any kind may be displayed inside the goals or walls. No extraneous equipment (cameras,
microphones, etc.) may be attached to these items.

This does not include or exclude team equipment like robots explicitly. Many teams use sponsor logos on their robots to finance their projects, so it should be clearly stated, that this is allowed as long as it is not forbidden through another instance.

We could also add the implicit rule, that no national flags are allowed on the field (or even venue?) at all.

It was identified at the committee meeting at RoboCup that it is unclear whether a kickoff (or other restart that starts with the ball on the mid-line) that reaches the end of the field constitutes carpeting or not. It does not, but the rules should identify this more clearly.

As an implication of the mandatory ball placement, the autoreferee must become mandatory, too, to efficiently send the ball placement position.

There are multiple implementations listed in the SSL wiki that were used and tested in previous RoboCups: http://wiki.robocup.org/Small_Size_League/Open_Source_Software

There is also a consensus application under development that aims at combining the decisions of multiple auto refs to make it more robust:
https://github.com/RoboCup-SSL/ssl-autoref-consensus

Is there any auto-ref that actually compatible with this new rules?
which auto-ref will be used for this year?

Automatic ball placement becomes mandatory for division A.

This change applies to both divisions. Speaking of the defense area, it is time to introduce some changes there. Every single team uses some sort of defenders that always move along the defense area. It is obviously a very effective defense strategy and rather easy to implement. To make the defense more interesting, the shape of the defense area will be changed to a rectangle (2.40x1.20m for the large field, 2.00x1.00m for the small field). The rules regarding the defense area will stay the same. This means that attackers and defenders are still allowed to move through the defense area as long as they don’t touch the ball.