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2005
Conference Paper
Titel
A microwave based tracking system for football
Abstract
To enable real time localisation and tracking of balls and players the "Cairos" system has been designed and set-up by Fraunhofer IIS, Erlangen, Germany on behalf of the Cairos technologies AG, Munich, Germany. System tests are currently being performed in Nuremberg's "Frankenstadion". Similar to the method used in GPS the position is determined by hyperbolic triangulation based on signal delay differences between transmitters and receivers. Whereas in GPS the position of the receivers (e.g. handheld device) is to be determined while the transmitters move on exactly defined satellite trajectories, the "Cairos" system works vice versa: the receivers are installed within the stadium on exactly defined coordinates and the objects to be localized are miniaturized transmitters mounted inside the balls or attached to the shin pad of the players. The carefully chosen dimensioning of the systems results in an accuracy within the cm range over the regional observation area of the football field while also allowing to resolve high speed movements of the ball. Locating the ball and the players via radio: Miniaturised transmitter are located at the objects to be localized. The core of the miniature transmitters consists of a two-chip ASIC solution, which sends up to 2000 brief code sequences per second in the ISM band at 2.4 GHz. For a sufficient monitoring of the pitch, up to twelve receivers per system are deployed that have to be placed in various heights above ground. These receivers are fixed at the floodlights and at different facilities inside the stadium. These synchronized receivers per stadium pick up the bursts and process them in order to obtain time-of-arrival-values. These are then handled by a computing cluster made up of Linux PCs to derive position data streams with an update rate of that of the burst rate. The system can handle more than 100 transmitters on the field. The locating system offers worldwide the first possibility to analyse all matches and players objectively with the same evaluation basis. To offer the public more attraction during the match, a lot of information from the running speed of a player to the length of a pass can be provided automatically. Soon, transmissions of football matches on TV can be enriched with a lot of information. Then, we will see and hear: The ball flew 12 centimetres above the crossbar. Or: The striker was very effective during the match with a running performance of 9.4 kilometres. This way, there is a new possibility for media companies to make the game more attractive and to awake a higher interest among the audience. Applications in other sport areas are also possible. The trajectory of a ski jumper could be observed and evaluated, for example. A very interesting field of application is the Formula 1 where the route of the racing cars could be examined. The range of further fields of application beyond sports are various. Exact position findings, for example, optimise the robot navigation in production halls or the logistic flows of goods.