KiRo- The autonomous table soccer player.
By Mike Hanlon
February 27, 2006
Meet KiRo- the completely autonomous table soccer playing robot that rivals all but the most nimble foosball freaks.
KiRo was developed at the institute for computer science at the University of Freiburg in Germany and was conceived for the purposes of research into the foundations of robotics and artificial intelligence (nice excuse guys). KiRo is capable of playing table soccer on a competitive level through a combination of various technologies built around a commercially available table soccer table.
It consists of four individually mountable custom made control units, a safety light grid, a camera overlooking the table and a standard personal computer. Using the camera it perceives the playing field and depending upon the current game situation, it decides how the rods under its control should be moved.
To allow the control system to track the ball, the base of the table is made of translucent glass, tinted green. The camera underneath photographs the ball 50 times per second, and sends this data to a built-in computer that maps the ball's position. Intelligent software then works out the effect of one of the figures kicking the ball.
The overlooking camera sends an image to the PC every 20 milliseconds. This information is transformed into an actual point on the playing field by first determining the centre circle and the orientation of the centre line. Regions of previously defined colours (in the form of players and the playing ball) are located in the image and transformed in to positions on the playing field.
The translational and rotational movements of a player's rod are achieved by means of a slide which is coupled to a belt drive and glides on a spline shaft when the belt is moved by a motor. A second motor and belt drive cause the spline shaft, and thus the belt pulleys of the slide, to rotate.
In tests conducted over nine days in which KiRo played against human competitors for around twenty-two hours impressive results were achieved. Amongst beginners and amateurs KiRo won a vast majority of matches. Even against advanced players KiRo managed to win a small number of games. It was only against tournament professionals that KiRo didn't stand a chance losing all of its matches.
"The team is now working on being able to stop the ball and pass it -- a capability that will be essential if the robot is ever going to beat good players" said one of KiRo's creators Bernhard Nebel.
The purpose of KiRo is to gain an insight into a number of research areas, such as sensor interpretation, control, autonomous systems, planning and machine learning. Through publications, knowledge and results are made accessible to the wider research community. The long term goal is to develop methods which can also be applied in other areas such as service robots.
To learn more about KiRo visit: http://www.informatik.uni-freiburg.de/%7Ekiro/english/