Tracking balls in sports

This invention relates to a system and method of tracking balls, possession and actions in sports particularly the various codes of football using oval balls and the various team sports using round balls such as soccer basket ball and netball.

Background to the invention

The idea of locating beacons in balls has been proposed.

USA patent 6117031 discloses a ball with a sound emitter for the visually impaired.

USA patent 5346210 discloses a hockey puck with a transmitter which is turned on when the puck is struck using a shock sensor and turned off using a timer.

USA patent 5976038 discloses a foot ball with a transmitter at each end transmitting different frequencies. These are detected by antennas off the field of play to detect line crossing as in out of bounds or a score.

USA patent 7091863 discloses a football with a readable sensor which can be read by readers located on the periphery of a playing field. The readers communicate with a computer so that the ball can be tracked as it moves over the field. The sensor in the ball may be a transmitter or transceiver and includes GPS, radio frequency tag, infra red or laser transmitter.

These systems are expensive as they rely on powerful transmitters and receivers that need to be located around the playing field. They also use expensive electronic equipment within the balls. Sport balls usually experience rapid wear and tear during a game and need to be replaced often.

USA patents 4762005 and 4824107 disclose a piezo based transducer arrangement to be incorporated into the gloves, headgear or body suit of the participants in martial arts. Wireless transmission of the piezo signals sends the data to a computer for analysis and display. The devices simply measure the number of impacts.

USA patent 5099702 discloses a force pad also for recording impacts.

USA patent 5336959 uses a piezo film to locate the point of impact of a ball.

WO 99/10052 discloses a boxing training system with sensors on gloves or a punching bag to record the number of hits.

WO 07/014702 discloses a system for determining at any time which player has possession of a ball and which players are in close proximity to the ball. An electromagnetic signal and an acoustic signal are transmitted from the ball and received by a data logger worn by each player and the distance between the ball and the player is proportional to the time taken for the electromagnetic signal and the acoustic signal to be received by the data logger.

It is an object of this invention to provide an inexpensive means of locating the travel path of a ball and also detect possessions and the methods by which it is propelled.

Brief description of the invention

The present invention provides a system for tracking balls in a team sport in which players kick, pass, bounce or carry a ball, which system includes:

• a ball equipped with a short range beacon emitting periodic signals; and
• a data logger worn by a player which includes a clock, a receiver for the signals from the beacon and a micro controller arranged to record receipt of signals, which receipt is indicative of the player being in possession of the ball or contesting the ball.

Preferably the data logger worn by the players also includes speed sensors, which enable the micro controller to track the path of the ball from player to player relative to the playing field. A suitable data logger is disclosed in Australian patent 2006222732 which discloses a data logger that can track the movement of a player on a playing field.

Preferably the signals are transmitted at a frequency which is not attenuated by the body of the players. Preferably a wireless beacon pulsing in the 5-10 Hz range may be used. Preferably two beacons are used one with a very short range of 40 -120 cm and the other with a range of 1- 5 metres. These signals are picked up by a data logger worn by the players and used to indicate that the player is either in possession of the ball (short range beacon) or contesting possession(longer range beacon). Alternatively the beacons may generate magnetic fields detected by sensors worn by the players or incorporated in the data loggers.

Instead of tracking the ball directly this system tracks the ball relative to the players and records and tracks possession from player to player. Currently available technology such as GPS (or wireless triangulation) provides the position of the players on the field and allows the player's movements during the game to be tracked. This invention adds information about which player is in proximity to the ball and has had impact with it (for instance a kick) and this enables a computer simulation of the path of the ball during play. This is an inexpensive alternative to the extremely cumbersome methods currently available for direct ball tracking.

The beacons may be powered by a battery or a piezo energy harvester mounted on the football cover which produces current from impacts to power the beacons. The occurrence of impacts can also be used to switch the beacons on and absence of impacts can turn it off.

To provide further information the system may provide a pressure pad integrated with a low power wireless transmitter located on the tongue of the football boot to transmit a signal when a ball is kicked. A kick results in a wireless pulse which is recorded on the data logger worn by the players.

Detailed description of the invention

A preferred embodiment of the invention will now be described with reference to the drawings in which:

• Figure 1 is a schematic circuit diagram for the beacon used in a ball;
• Figure 2 is a schematic circuit diagram of the data logger used in this invention;
• Figure 3 is a schematic of the signals recorded on the data logger;
• Figure 4 is a schematic diagram of players contesting possession of a ball in accordance with this invention.

The system of this invention preferably includes 2 wireless beacons inside the ball, as shown in figure 1; one at 2.5kHz and one at 4kHz. Both beacons will pulse the wireless signal at 5-10Hz. One will have a range of about 40-120cm and the other a range of 1 - 5 metres. The beacons will be powered with a small lithium battery at 3V. As shown in figure 1 an energy harvester may be used instead of a battery.

Corresponding pick up coils inside the data logger device, illustrated in figure 2, worn by the players, will listen for the beacons. A preferred data logger is of the type described in Australian patent application 2006222732.

Since the data logger is worn on the athlete, a pickup of the short range beacon will indicate possession of the ball and a pick up of the longer range beacon will indicate proximity to the "play" (i.e. the athlete was involved in the play). As shown in figure 4 the data collected from the ball beacon can indicate if the player is in possession of the ball or contesting the ball or too far away to be directly involved in the contest for the ball. In combination with the other data streams from the data logger, it is then possible to track possessions, disposals, turnovers (when one team transfers the ball to the other team), and even information like number and time of bounces etc.

Since the electronics used in the ball are low powered, the battery will last longer than the ball. The electronics are also inexpensive so that the cost of the instrumented balls is only a small increment above normal ball cost. If desired a switch on/off functionality via a reed switch in the electronics may be provided. Passing a magnetic wand over one or more balls would switch them on or off.

In one embodiment the ball transmitter uses three timer circuits to produce an out put signal. Timer 1 enables the power for operation of the transmitter and may be set to a suitable interval such as 5 minutes. A trigger circuit based on a shock sensor activates the circuit once the ball is kicked off. The ball then transmits continuously for a maximum period of the selected interval (5 minutes). If the ball is kicked again the timer is reset and starts again. Power is only permanently provided to the trigger circuit. The receiver circuit on the data logger uses two sets of MFB filters used with 90 degrees oriented coils for maximum reception.

An alternative is to have a motion activated on switch. When the ball bounces or experiences impact, the wireless beacon turns on and runs for a set period (such as 5 minutes) at which time it turns off if there have been no further impacts. Another alternative is to power the ball via an energy harvester and super capacitor. For instance a piezo device between the skin and bladder of the ball could generate voltage and charge a super capacitor to provide power to the beacons.

Those skilled in the art will realise that this invention provides a unique system that is able to be used in a range of sports to track the movement of the ball relative to one or more players. Those skilled in the art will also realise that this invention can be implemented in embodiments other than those described without departing from the scope of the appended claims.