Positioning systems
3. Electronic positioning systems for players and ball
Many recent applications work the other way around, so to speak: instead of transmitting referee decisions to a control centre, as described in the previous section, they provide referees with electronic aids for decision making.
Figure 4: Real-time determination system for monitoring the positions of ball and players, which are equipped with sensors (FR 2 695 042)
For a person standing on the pitch it is often impossible to judge correctly whether a goal was achieved or whether there was an offside position. This has led to the development of modern positioning systems which make it easier for match officials to correctly assess game situations. Positioning sensors incorporated in the players' outfit and the ball transmit the coordinates of players and ball to a central computer that will determine eg. an offside position immediately and send an alert signal to the match officials. The referee and the assistant referees can then check whether a certain player was actively involved in an action that must be penalised.
| Publication number | Year | Title | Brief description |
|---|---|---|---|
| WO 2007/099502 A2 | 2006 | Method and System for the Automatic Detection of Events in Sports Fields | Camera-based system with quick image processing and real time calculation of trajectories of moving objects for determining the position of the ball near the goal |
| WO 2006/111928 A2 | 2006 | Method and system for the detection and the classification of events during motion actions | Another localisation system for detecting offside positions, in particular |
| DE 10 2005 013 225 A1 | 2005 | Objektverfolgungs- und Situationsanalysesystem | Object tracking and situation analysis system with central positional data processing unit that selectively activates and controls the individual detecting units for tracking specific objects (ball or individual players) |
| WO 03/070336 A1 | 2003 | Sistema de dispositivos electronicos de ayuda abritral para el futbol | System for capturing the positions of players and ball; generates electronic and optical signals to indicate offside positions or goals |
| DE 102 52 934 A1 | 2002 | Verfahren zur kontinuierlichen Echtzeitverfolgung der Position von wenigstens einem mobilen Objekt sowie zugehörigen Sendern und Empfängern | Positioning system for electronic real-time monitoring of actions on a football pitch |
| WO 01/02067 A1 | 2000 | Sistema de deteccion del fuera de juego | Localisation system signalling a possible offside position to the assistant referee, who decides whether or not the signal shall be transmitted to the referee |
| FR 2 726 370 B1 | 1994 | Systeme de controle du positionnement dans le domaine du sport, d'une balle et des joueurs | System for determining the position of players and ball and for detecting offside positions |
| CH 628 192 A | 1978 | Fernsehanlage für die Überwachung und Beurteilung bzw. Leitung von Feldspielen, insbesondere Fussballspielen | Video system for superimposing match images, with coordinates for direct checking of decisions by the referee |
Since the "radio flag" for establishing electronic communication between match officials was adopted by football officials only about 30 years after having been filed with the patent office, we can assume that some ideas, which might be put into practice today, are likely to lie dormant in patent literature for quite some time and will be implemented, if ever, on the long run only.
There is still a contentious debate on whether or not to accept TV replays to aid referees in their decision making. The so-called electronic positioning systems even surpass the accuracy and timeliness of video recordings, since they provide the referee with immediate information on goals or offside positions without requiring the game to be interrupted for decision making (see also section 6 of chapter "The Football" for further optical systems for localising the ball or systems using a "smart football" with sensor chip for these purposes).
Electronic or video-based localisation systems do not only serve to assist referees. They can also be used for general match documentation purposes. This application is increasingly important in practice. They allow to gain valuable information about the players' movements during a match or training unit, or statistical data on ball possession, duels won or shooting precision. These data are used to analyse match tactics and evaluate the players' qualities (see also section 6.4 in chapter "The Football").
A detailed presentation of such (usually computer based) systems would go beyond the scope of this chapter. Representative examples of patent documents relating to this issue are summarised in the "Documents" section, in chapter "Match analysis".