We are a long way from the days when people hunted for a bicycle pump to inflate their soccer ball. A photo posted on Reddit shows the "Al Rihla" balls , before a game, attached to a multi-socket for recharging as if they were smartphones .
Produced by Adidas, the ball, which takes its name from the Arabic word "Al Rihla" (the journey), provides data such as speed and direction and allows offside calls by the VAR (Video Assistant Referee).
Al Rihla: the hi-tech ball with inertial sensors
The system integrates an inertial measurement unit (IMU) and is inspired by a fairly widespread navigation application in the avionics sector. The sensor measures velocity, orientation, and magnetic field using an accelerometer, gyroscope, and magnetometer to obtain an object's direction, acceleration, and position in space.
The IMU system is powered by a small battery , which Adidas says can last for six hours of active use, or up to 18 days when the ball is not in use. The sensor, which weighs just 14 grams, provides real-time ball tracking and cameras positioned around the pitch help referees determine offsides with greater accuracy.
Data sampling takes place 500 times per second and is able to detect the movement and speed variation of the ball. Data is sent in real time from the sensors to a local positioning system (LPS), which requires a setup of antennas installed around the playing field, in order to collect and store the data for immediate use. When the ball goes out of bounds and a new ball is in play, KINEXON 's backend system automatically switches to the new ball data input without the need for human intervention.
Hi-tech balloons and tracking system
To efficiently plan and execute trajectories, the use of a drone is essential for an accurate representation of the ball's position in a Cartesian frame of reference. Indeed, the balloon uses a Marvelmind configuration to estimate the X and Y coordinates. Finally, a Lidar physically attached to the drone is used to determine the height (Z coordinate).
Marvelmind Robotics is a company that develops GPS systems for indoor location using ultrasound beacons . These systems can easily be adapted for outdoor environments such as states where four fixed beacons are positioned at a height of approximately 1 meter in each corner of the field. A fifth mobile beacon is attached to the drone whose position is tracked by the fixed beacons. In this application, the data is accessed via a modem using a program written in the C language. This algorithm decodes the data and transmits it to a MATLAB/Simulink program via Universal Datagram Protocol (UDP). All of this runs on Intel Nuc mini PCs.
Finally, the detection system is supported by optical tracking created with twelve Hawk-Eye cameras installed throughout the stadium to follow the ball and the players. The combination of these two technologies allows to accelerate the VAR decision-making process , in order to make offside decisions more accurately, but also faster than in the past, a key priority for FIFA in this world championship.
FIFA has called this technology “Semi-Automatic Offsides” , which is largely managed by artificial intelligence, but which retains the fundamental element of human verification.
The article Al Rihla: this is how the super hi-tech ball of Qatar 2022 works was written on: Tech CuE | Close-up Engineering .