One may easily recall Frank Lampard’s disallowed goal in the match between England and Germany in the 2010 World Cup knockout stage where the ball clearly bounced behind the goal line but the Uruguayan referee waved play on.
Over recent years, Fifa has started to push for the introduction of Goal-Line Technology (GLT). Through the International Football Association Board (IFAB), Fifa started to explore currently available goal-line technology. Following an initial testing phase back in 2011, eight candidate technologies with the required fitness and readiness level were evaluated. Two technologies passed the first test phase – Hawk-Eye and GoalRef.
The system can capture the 3D position of the ball with high precision
Hawk-Eye is the invention of British engineer Paul Hawkins. Utilising his academic know-how, his entrepreneurial skills and his passion for sport, Hawkins developed a system, initially for cricket, which could track the ball’s trajectory. The system, largely software based, utilises multiple high-speed video cameras mounted at different locations around the area of play. It is based on the principle of triangulation, which is the process of determining the position of an object from the known position of two other objects.
Triangulation has various other applications, such as the Global Positioning System (GPS) and Earthquake localisation.
The GoalRef system was developed by German research institute Fraunhofer and Danish sports equipment manufacturer Select Sports. It is based on the principle of electromagnetic induction, discovered by British scientist Michael Faraday 200 years ago. A low-frequency magnetic field is generated around the goal. This magnetic field is monitored via coils installed in the goal posts and crossbar. A passive electronic circuit is integrated in the ball.
As the ball passes through the goal, the passive electronic circuit interacts with the generated magnetic field and alters the properties of the latter, which is monitored by a system computer.
Once a goal is detected, both the Hawk-Eye and the GoalRef systems send an encrypted radio message to a wristwatch worn by the referee, vibrating and displaying that a goal was scored.
The second IFAB testing phase conducted in 2012 tested the limits of both Hawk-Eye and GoalRef. The field tests involved sessions with real players, simulating goal situations and goal line incidents even in difficult scenarios such as obstructed goal line views, and bad climatic and visibility conditions.
In April 2013, Fifa announced that German company GoalControl GmbH had won the bid as the goal line technology provider for the 2014 World Cup. Its system, called GoalControl 4D, uses 14 high-speed cameras (seven on each goal), mounted on the roof of the stadium. Utilising the same principle as Hawk-Eye, the system can capture the 3D position of the ball with high precision.
The system also provides the capability of rendering the trajectory taken by the ball and hence providing the fourth time dimension. France was the first 2014 World Cup team to be awarded a goal with the use of goal-line technology during their match with Honduras.
The world’s engineers are involved in creative technologies that make important events like the World Cup possible. However, they are also involved in the making of devices and equipment that we use on a daily basis and take for granted.