[robocup-small] Rule changes for 2005

[chelberg at endor.cs.ohiou.edu]

Dear Robocuppers,

Here is our team's (RoboCats) response to the proposed rule changes:

In message <1100279875.7178.39.camel at yoda>, Sean Verret writes:
>Change 1:
>
>The dribbling distance will be set at 500mm for both active and passive
>dribblers.

We don't have a problem with this, but would like some justification
for the particular distance (500mm) chosen.

>
>Change 2:
>
>For all restarts where the ball has gone out of bounds and the rules
>state the ball is too be placed ON a boundary line or within 10cm of a
>boundary line, the ball will be instead moved towards the middle of the
>field to an imaginary line that is 10cm any of the boundary lines that
>the ball is within the 10cm wall.  Needs rewording but I think it makes
>sense.
>

Again, we don't have a particular problem with this rule, but we
should be discussing the real reasons behind its introduction (balls
going out of bounds too often.  Raul's suggestion for a slopped wall
might help this problem as well.  If I remember correctly, a ball
isn't out unless it is all the way past the line.  Slopped walls will
help keep balls from going out as easily, even on restarts.

>Change 3:
>
>The referee box will send a neutral restart command 10 seconds after all
>restarts.
>

Sounds good.

>Change 4:
>
>No more bluetooth is allowed in the small-size league, and all other RF
>decisions will be left to the OC based on local conditions.

We strongly support this decision. There is a VERY good reason why
other leagues have banned bluetooth.  Although it is relatively low in
power, it is very bad about coexisting with other 2.4GHz
transmissions.  Mark Goldman (one of my students) already sent a
detailed explanation for why bluetooth is so bad when present near
other 2.4GHz protocols (802.11(b and g)).  In practice, 802.11 cannot
be used on the same field as bluetooth.  It may also interfere with
other league's operating on 2.4GHz as well, e.g. Aibos as small-sized
fields are often within range of their fields.

In addition, there is no provision in bluetooth to be able to "change
channels," so if a team can only play with bluetooth, it is in
violation of the rule that states that teams must have alternate
channels for wireless comm.  802.11b has 4 non-overlapping frequencies
that it can switch between.  In Lisbon, each league requiring 802.11b
was given a different 802.11b frequency to use.  However, the
small-sized league had to share with the humanoid robot league.  This
worked fine, but when bluetooth teams were broadcasting, we had near
100% packet loss!  

>
>Change 5:
>
>Corner kicks will follow with change 3.

See 3 above.

>
>Change 6:
>
>The EC/OC/TC will decide upon ALL yellows, blues, greens, cyans, and
>pinks allowed to be used by robots before the competition and will make
>enough of these colors available at the competition for each team to
>field 6 robots.

We do not see that this has ever been a problem.  We believe that if
we are to move to a more general vision architecture, with available
lighting, eventually moving outdoors, we will have to start dealing
with color variability.  The current setup where teams agree on colors
works quite well.

>
>Change 7:
>
>We will have 6 robots per team

We strongly disagree with this.  We feel that the field will become
too crowded with more robots, after we just opened things up by
creating a larger field.  In addition, the additional cost is not
justified by any issues that come up with 6 robots that do not come up
with 5.

>
>Change 8:
>
>The time of game will include 12 minute halfs, 5 minute half time
>breaks, each team retains its color for the duration of the match and
>colors are decided along with the referee 1 hour before the match.

We have no problem with this rule change.

>
>Change 9:
>
>There will be no chip kicks allowed during any restart.  Chip kicks (of
>any height) will be allowed during all other situations.

We like this rule change, if coupled with the enforcement of the 80%
rule.

 -- Prof. David Chelberg (chelberg at ohiou.edu)
    Team Leader RoboCats (Ohio University)