Electrical & Electronics Engineering DepartmentProject No: 1

Development of Multi-Agent Robot Systemsfor Robotic Soccer

byİbrahim Can Yılmaz

AdvisorAsst. Prof. Dr. Ahmet Özkurt

RoboCup Small-Size League The RoboCup Small-Size robot soccer League (SSL) is a research domain to study multi-robot planning and execution under the uncertainty of real-time perception and motion in an adversarial environment. The RoboCup SSL is set as a soccer game between two teams of six robots each, playing with an orange golf ball in a field of predefined size with line markings. The top of each robot is a unique colored-coded pattern to enable a set of overhead cameras to determine the position and orientation of each robot.

Contents of Project This part of the Project includes hardware implementation of fast response robots, processing of football field, detection and classification of objects in the field, converting image into marks that represent only necessary objects (like robots, ball, goal etc.), preparing a user interface to do some basic movements (displacement, shooting, passing etc.) with selected robots

How It Works? System is running in a infinete loop -of course while program is running- that working between computer, camera and field. Camera takes a view from the field and sends the data to computer. Computer processes data and calculate states of objects. It sends a command to robots with radio signals. Robots move in the guidance of computer. Positions and orientations of objects are changed and everything starts over again.

Hardware Design

Server: It consists of Arduino UNO and an RF transmitter. It takes information from Matlab via serial port and sends it to the robots.

Robot implementation was performed by using an Arduino UNO, RF receiver and dual motor driver carrier.

Filtering Filtering can be called as «thresholding», because some thresholds are set and the image re-formed by respect to these thresholds. For example, RGB code of orange is [255 127 0]. It means the color include full red, semi green and no blue components. And some intervals are set by respecting to this values and the pixels are set as ‘0’ or ‘1’.

Dokuz Eylül Üniversitesi, Mühendislik Fakültesi, Elektrik-Elektronik Mühendisliği bölümüKaynaklar Yerleşkesi, 35160 Buca/İZMİR, TÜRKİYE

Tel: +90 232 301 7155

Object Detection While acquiring live-image instantaneously, these colors on the robots are processed and all of them labeled in a matlab struct. First of all, acquired image to be subjected thresholding and it is converted black and white image. After that operation, small groups of pixels are neglected by using ‘bwareaopen’ command. Eventually, connected components, in other word pixel groups that are neighbor with each other, aligned as objects and their some feature, like area, color or central coordinates etc., can besaved in a struct.

Converting real-image to virtual-image

Mathematical expressions of shooting

Conclusion The main idea of this project is to design a well-orginezed multiple robot team which can move in dynamic environment. The system built on colors and positions of robots and ball. Robotic Soccer is a highly complex domain that has largecomplication for movements of robots in either robotics or path planning strategy. Mobile robots in the project are designed as differential-drive robots and it makes running on a straight line very difficult. After making sure that ball casters ann motors are well-placed, movement of robot is controlled instantaneously from vision system. It must be straightened if it deviates from virtual path. Global vision is the most important part of this project, because everything recognized from colors and every movement calculated base on colors. So, the lightning of field come into prominence, because the lightning change too much the difference between real color and perceived one from camera. Shortly, constant lightning system must be used to decreasing the faults.