Patent ID: 10953279

Abstract:
The system (10) of FIG. 1 uses fixedly-located master and slave smartphone devices (12, 14) to determine a player position of a player (20) within playing arena, such as a tennis court. The master device (12) makes a local determination of the speed of sound using an audible ping to the slave device displaced from the master device by a known distance. The slave device (14) also responds with a time stamp associated with the receipt of one or more pings. Correlation over successive RF-reported time stamps allows the master device (12) to assess, relative to its own internal reference clock, a time offset and drift for a local clock in the slave device (14). A RF connection to a communications circuit and sensor (18) arrangement located in a racket held by a player permits the master device (12) to assess a time offset and drift for a local clock associated with the sensor. The sensor (18) further includes a gyroscope, accelerometer and magnetometer that cooperate to record movement or orientation of the racket, and which information is uplink reported over the RF connection to the master device. When an amplitude or modelled sound profile for a “hit” event (24) is detected by both the master and slave devices (12, 14) and the hit event time-stamped by the devices in the system and reported to the master by the communications circuits of the racket and slave units, the master unit is able to triangulate the position of the hit event relative to known dimensions of the playing arena. Continuous reporting of movement of the racket relative to the previous hit event can therefore be displayed to show movement of the player around the court relative to detected sound events.