[robocup-small] SSL 2009 Rules

[Stefan Zickler]

Hi All,

the TC has finished discussing the 2009 rules.
The new rules and field dimensions are now available on the web:

http://small-size.informatik.uni-bremen.de/rules:main

Here is a summary and explanation of the changes:

1) Field size
After the decision of the RoboCup trustees to unify field sizes among
SSL, SPL, and Humanoids League, all leagues have finally come to an
agreement on field size. We are adopting the carpet size and field
boundary location of the humanoid league. Effectively this means that
the inner playing surface shrinks a very small bit, while the outer
runoff area grows a lot. All inner field lines (defense, center
circle, goals...) stay the same. Furthermore, all lines stay at the
same 1cm width. Since we do not really require a 675mm runoff area,
the TC has decided to designate the outer 425mm of that area for the
referees to walk on during games. This should actually be beneficial
because at past RoboCups it has been quite challenging for referees to
walk around the field as teams tend to put their cables and equipment
there. Teams should not need to worry to cover this referee walking
area with vision systems, as long as their robots are well enough
controlled not to enter this area accidentally.

2) Game time
The game time has been reduced from 15 minutes per half to 10 minutes
per half. The reasoning is that most RoboCup games tend to either be
fairly unbalanced where a clear winner is easily determined within 20
minutes, or that neither of the teams is able to score at all which
often leads to painfully long games without any activity at all. To
keep games more interesting, the TC has decided to reduce the game
time.

3) Total time allotted for timeouts
The total time available for timeouts has been reduced from 10 minutes
to 5 minutes. The main reasoning here is that the public often loses
interest during long timeout periods. The TC agrees that timeouts
should be intended for quick fixes and adjustments, not for attempts
to implement new features (which usually don't succeed during a
timeout anyhow). The total number of timeouts stays the same however.

4) Clarification on the term "game stoppage"
As was brought up during public discussion, there was some ambiguity
in the rules as to when it is ok to request things from the referee,
and what exactly defines a "game stoppage". This has now been
clarified in the rules.

5) Change of the prohibited area when ball enters play
In the original 2008 rules, there is a rule prohibiting robots to be
closer than 700mm to the defending team's goal-mid-point when the ball
enters play. This rule was changed to 900mm at RoboCup 2008 due to the
fact that we had a non-circular defense area. For 2009 we have now
changed this rule to represent the area 200mm away from the defense
area.

6) Referees are requested to wear non-marker-like clothes
A sentence was added to request that referees should not wear clothes
+ shoes which represent marker colors.

7) Removal of robot height exception for on-robot vision systems
The robot-height exception in the rules which was intended for local
on-robot vision has been removed. To the TC's awareness, no team has
ever made use of this rule, so this should not be a problem.


Best regards,

Stefan (on behalf of the SSL TC)