Bahia2D – Team Description Marco A. C. Simões 1, 2 , Helder Guimarães Aragão 2 , Victor Souza 1 , Simon Viegas 2 , Hugo da Luz Silva 1 , Jessica Meyer 1 1 Computer Architecture and Operating Systems Group(ACSO) State University of Bahia (UNEB) Rua Silveira Martins, 2555, Cabula. Salvador – BA – Brazil 2 Intelligent Computing Research Group(GPCI) University Center of Bahia (FIB) Rua Xingu, nº. 179, Jardim Atalaia/STIEP. Salvador – BA – Brazil marcosimoes@fib.br , {helderfib, okvictorok, simonpiata}@yahoo.com.br , {hugodaluz, jessy.meyer}@gmail.com Abstract. This paper presents the initial research from Bahia Robotics Team. This is a new research group created to investigate the application of artificial intelligence methods in the standard problem of robotics soccer. In this work, fuzzy controllers are used to improve some abilities of the players. In the case of the attackers, the kick and the positioning ability were improved. The midfielders had their positioning and passing ability improved. The goalkeeper and the defenders had their positioning ability improved. The generated Bahia2D soccer team was tested in matches against some victorious teams from Robocup Brazil Open 2006 and from previous editions of the Robocup World Competition, validating that fuzzy controllers are a good solution for the robotics soccer. The positive results achieved and the ongoing works to improve the current limitations are also presented. 1. Introduction The Bahia2D team is entering into its first year of competition. It has been developed by Bahia Robotics Team(BRT) consortium since the second semester of 2006. BRT represents the union of the Computer Architecture and Operating Systems Group(ACSO) and the Intelligent Computing Research Group(GPCI), in order to investigate the application of artificial intelligence methods to autonomous robots, as proposed by Robocup international research initiative. At this moment, BRT is working on the development of a team for the 2D Soccer Simulation League. Our goal is to develop fuzzy controllers for specialized agents in the positions: goalkeeper, center defender, wing defender, defensive midfielder, offensive midfielder and attacker. As a first work, the focus is only at kicking, passing, positioning and decision taking abilities at the controllers. At this stage, the Bahia2D team is composed by reactive agents. Our study is not worried about environment modeling details. For this reason, a base team to treat environment modeling and communication details was chosen. The UvA Base source code is used as base team, it was chosen because of its availability, quality of its world model and good abstract interface to send commands to simulator. The first problem handled was the attacker ability to kick to opponent goal. In the base code, there were no analysis of the opponent’s goalkeeper position and kicker position. Fuzzy logic was used to deal with these variables. The second problem was the attackers positioning because these agents frequently became in offside position. To make it easier for attackers to receive the ball without staying in offside position, the base world model and fuzzy logic were used. Based on the experience with these two problems, solutions for the positioning of the other players were also proposed. The last focused problem was the decision taking. Players with ball possession, can decide whether to kick to opponent goal, to pass the ball to the best positioned teammate, or to keep the ball. Defenders area slightly different because when they can't pass, they always clear the ball. Solutions to deal with this decision taking problem are presented.