Semi-Automatic Offside Technology (SAOT) is a support tool for video match officials and field officials, helping them make faster and more accurate offside decisions. In the opening match between host Qatar and Ecuador, this technology has a sense of presence. Only 3 minutes into the game, Ecuador scored a goal, but the semi-automatic offside technical judgment made the goal invalid.
The technology includes three parts: camera, sensor and artificial intelligence software. Twelve cameras located on top of the stadium track the ball and 29 data points on each player. This system will use artificial intelligence to assist the referee to make more accurate offside judgments, minimizing the occurrence of offside misjudgments.
In this World Cup, there is a CTR-CORE in the center of each game ball, that is, a central chip is implanted inside the football. Although similar technologies have long been used in basketball, tennis and other sports, it is still Used for the first time in football.
In order to make the football have excellent anti-seismic performance, the new suspension system in the inner tank of the official World Cup ball "Al Rihla" uses multiple connecting columns to fix the chip in the capsule shell at the center of the ball, thus ensuring the balance of the ball Not affected. At the same time, the suspension system is also equipped with built-in motion sensors, making this technology imperceptible to players and will not affect any sports performance. The device, which is said to weigh 14 grams, is actually an integration of two independent sensors that work simultaneously, one of which is an ultra-wideband (UWB) sensor that can track and acquire precise position data of the football, and can also transfer the data Real-time transmission to the background system. In the process of judging whether Ronaldo's head touched the football this time, the inertial measurement unit (IMU) sensor is used to detect the subtle movement of the football.
Through the above content, we will find that the protagonist of the "black technology" here is the inertial measurement unit (IMU). An inertial measurement unit is a device that measures the three-axis attitude angle (or angular rate) and acceleration of an object. Physical motion can be converted into electrical signals, amplified and processed by electronic circuits. Generally, an IMU includes three single-axis accelerometers and three single-axis gyroscopes. The accelerometer detects the acceleration signals of the three-axis independent object in the carrier coordinate system, and the gyroscope detects the angular velocity signal of the carrier relative to the navigation coordinate system. Measure the angular velocity and acceleration of an object in three-dimensional space, and use this to calculate the attitude of the object.
In actual work, due to various unavoidable interference factors, the gyroscope and accelerometer produce errors. From the initial alignment, the navigation error increases with time, especially the position error. This is the inertial navigation system. major drawback. Therefore, it is necessary to use external information for assistance to realize integrated navigation, so as to effectively reduce the problem of error accumulation over time. To increase reliability, it is also possible to equip more sensors per axis. Generally speaking, the IMU should be installed on the center of gravity of the measured object.
IMUs are mostly used in devices that require motion control, such as cars and robots. It is also used in occasions where attitude is required for precise displacement calculation, such as inertial navigation equipment for submarines, aircraft, and spacecraft.
