[robocup-small] Ideas for 2007 Rules

[Paulo Costa]

A few quick comments:


>- Move to a partially automatic ethernet-based referee box
>...
>
>We could try to develop an ethernet+serial referee box during the
>    transition period.  I would be willing to help out in that effort.

I think it is a good idea to have both systems. I suggest that the ethernet 
system uses UDP with broadcast. The MSL modified our referee box to use TCP 
and it's very awkward. With an UDP broadcast the referee commands are 
"public" like a real referee and there is no connect/disconnect problems 
and nagle tweaking.

>- Are chip kicks now too powerful for the goalie?
>
>    Proposal: allow a second defender to enter the defense area for a
>    limited time (3 seconds perhaps?)
>    Alternate Proposal: split the defense area into a small "no two
>    defenders" area, and a larger "no goalie touching" area.  This will
>    allow defenses a better chance of blocking while still preventing
>    walls across the entire goal.
>...
>

The second defender for a limited time (counting only after the ball is 
play) seem a good option anti deadly corner kick.


>- Teams must prove kickers are legal
>
>    Right now, there are a lot of chip kicker designs, including
>    short-travel wedges (the FU-Fighters 2005 design), wedges that
>    travel near the robot, and "scoops" that sweep outward from the
>    robot.  Some are easy to prove legal, such as the short travel
>    wedge, since the ball cannot ever violate the 20% rule throughout
>    the travel.  Scoop kickers are a bit more problematic, as legality
>    depends on the dynamics.  The ball *could* become illegal, but its
>    unclear if it *does*.  At the last competition the rules committee
>    ended up having to show kickers were illegal, when really the burden
>    should be on the teams.

A clarification, the team must prove that it is legal on the general case 
or in every case? Like when another robot is pushing the ball against our 
kicker in the exact moment that its kicks or when a bouncing ball hits our 
robot while we are trying to kick or when a high ball falls over to top of 
the robot and then rolls to the field (Officially, every robot violates the 
20% rule in this case)...


>- General kick speed limitation?
>    Maybe we should limit kicks to some reasonable upper limit, such as
>    10 m/s (CMDragons was using 15 m/s for the last three games).  What
>    is needed however is some way of enforcing this.  I don't have any
>    good ideas on this, but maybe someone else does.

More out of general safety this would be a good idea but I fear that 
currently, it is practically unenforceable.


>- Increase team size to 6 robots
>    I think this might be the year to increase the number of robots, to
>    add more possibilities for passing, and to get closer to 11-vs-11 in
>    a manageable way.  Teams are scoring now, so we don't have the
>    situation of a few years ago with many 0-0 or 1-0 games.  However,
>    in order to prevent teams from stacking to defense too much, we
>    could *require* that at least one robot stay as a forward at all
>    times (i.e. a team must keep one robot on the offense side of the
>    field at all times).  This is kind of a reverse-offsides rule.

It doesn't look a good idea. From the beginning, the field was too small 
for the size versus number of robots and we had to enlarge the field *a 
lot* to make it sane (also, the chip kicker helped open the game). Let's 
not make the mistake of crowding it again.
Also I think that it is fair that a team can increase their passing 
possibilities by bringing more robots from their defense. An offensive play 
should weaken the defense. Increasing the number of robots encourages teams 
to keep 2 or 3 robots forming an extended goal keeper.


>- small field size increase (outer size unchanged)
>
>    With kicks now given 100mm from the border, the outer 300mm border
>    is not really necessary.  Thus, without any changes to vision
>    systems, we could decrease the outer border to 200mm on each side,
>    enlarging the field by 200mm in both dimensions.
>...

Another option would be to start taking the kicks with the ball over the 
line. That would be easier for the referees and there would be less 
variance on the place where the ball is put.

Paulo Costa