GB2543476A

GB2543476A - System for locating golf balls

Info

Publication number: GB2543476A
Application number: GB1515315.8A
Authority: GB
Inventors: Barrett Alan
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-08-28
Filing date: 2015-08-28
Publication date: 2017-04-26
Also published as: GB201515315D0

Abstract

A system for locating lost golf balls includes a golf ball that incorporates a passive transponder and a finder containing a radio frequency transmitter/receiver capable of exciting the passive transponder by way of an unmodulated RF signal in the HF band and detecting a modulated signal emitted by the transponder. The finder has a handle with a user interface at one end of a shaft and detection means at the other end of the shaft. The shaft can be extendable, collapsible or telescopic. The user interface may indicate signal strength, battery status and/or operation status. The strength of the excitation field may be manually variable. In one embodiment there is no wired connection between the ends of the shaft, with connection made by way of a short-range radio, ultrasonic, optical or through-air optical means. The finder may contain means for mitigating human exposure to the strong RF excitation field source.

Description

System for locating golf balls.

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’ I - Description off the Invention Statement of Invention

According to an aspect of the present invention there is provided a golf-ball finding system according to Claim 1

Brief Description of the Drawings

Embodiments of the present invention will now be described in detail, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a schematic diagram of a golf-ball finding system according to an embodiment of the present invention;

Figure 2 is a schematic diagram of a golf-ball according to an embodiment of the present invention;

Figure 3 is a schematic diagram of a golf-ball central core with transponder according to an embodiment of the present invention;

Figure 4 is a schematic diagram of a transponder according to an embodiment of the present invention, showing the transponder in perspective and plan views;

Figure 5 is a schematic diagram of a finder according to an embodiment of the present invention;

Figure 6 is a schematic diagram of a finder detection module according to an embodiment of the present invention.

Detailed description

This invention is of a system that takes a different approach from that outlined for the systems referred to in the Background to the Invention, which are aimed at being able to detect a bail at a relatively long range.

Instead, the system that this invention comprises concentrates on the essential functional aspect of finding golf balls in the most common scenarios for a missing ball: when the ball 20 is missing in possibly rough, heavily-vegetated and wet terrain 70, but its very approximate general location is known - for which, once the user 10 of the finder device 40 has come to that general location, the capability for long-range detection is not necessary, and a detection-range of just a few metres is adequate to make the search much easier within that general area, particularly when coupled with characteristics that then make it easier to closely locate a missing ball 20 when the view is heavily obscured.

The invention, which is designed, as its fundamental requirement, to achieve such a detection-range of a few metres with the capability for convenient close location, comprises a system of two main physical elements, each of which in turn comprises a number of subsidiary elements.

The first main physical element is a golf-ball 20 that contains a compact passive transponder 22. Being passive (i.e. without its own power supply) rather than active, the transponder 22 permits much lower cost for the ball and an indefinite playing lifetime, and permits simplicity and practicality for the user by avoiding activation/deactivation procedures, the need to follow these procedures, and the consequent need to remember to follow the said procedures. Also by virtue of being passive and so not having a battery, the said transponder 22 has smaller physical volume and smaller physical mass, which make it easier to obtain correct balance and weight for the ball 20 ,

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* I •and the said transponder 22 is able to be more spatially compact so that it fits entirely within the central region 24 of the ball 20 without the compromise to the efficiency of its antenna 28 that the geometry of a battery would entail. Also by virtue of the compactness of the transponder in its entirety, no flexible parts (whether for antenna or anything else) need to be incorporated outside the central region 24 of the ball 20, to simplify as much as possible the manufacture of the ball 20.

The second main physical element is a finder device 40 that enables location of the said golf-ball 20 by detecting the signal 90 emanating from the said golf-ball 20 and providing an indication of its strength by which the user may ascertain when the said finder 40 is getting closer to or further away from the said ball 20.

The said finder device 40 produces a near-omnidirectional unmodulated radio-frequency electromagnetic excitation field 80 that, when strong enough in the vicinity of the golf-ball 20, energises the circuit 26 of the transponder 22 within the golf-ball 20, so that the transponder 22 is able to emit a distinctive and detectable signal 90. By virtue of the excitation 80 not requiring any modulation, the use of a strong excitation source 56 & 57 for maximum range is possible without also creating high levels of modulation side-bands, thereby being able to use a permitted frequency with relatively low limits either side of a narrow main band.

Whether or not the circuit 26 of the transponder 22 is energised, the transponder antenna 28 passively re-radiates 90 at the frequency of the excitation field 80 incident upon it, and the said antenna 28 is designed to be resonant at the frequency of the excitation field 80 so that the strength of the re-radiation 90 is maximised and also so that the voltage available for the transponder circuit 26 is maximised.

When the transponder circuit 26 is energised, the transponder creates upon its passive re-radiation 90 of the incident excitation field 80 a preconfigured signal pattern (e.g. a tone, or a pseudorandom bit sequence) that is distinctive and hence identifiable and detectable amidst the background interference (chiefly from the excitation signal 80) by virtue of appropriate signal processing in the detection circuit 58 of the finder 40 that looks exclusively for this pattern. When detecting the said preconfigured signal pattern the finder 40 is so arranged to for parameters of its signal to the user DO to be in dependance of the strength of the detected signal, so that the user may seek out an increasingly stronger detected signal in order to home in on the missing ball 20.

In a preferred embodiment, which involves the greatest simplicity for the user, the said preconfigured pattern is common to all balls 20 of the type to be detected by the finder 40. In an alternative embodiment, where the finder 40 would only detect a single particular ball 20 (or balls 20) on a given occasion, each ball 20 could have its own pseudorandom code, which the finder 40 would have to learn beforehand or otherwise become preprogrammed with.

The finder 40 and golf-ball 20 are designed to operate with an excitation frequency in the HF band where, at the preferred frequency (used for RFID appications), the skin-depth in salt-water is approximately 6cm and significantly more in fresh water, so that the system is tolerant of terrain 70 that may include heavy vegetation 72 and very uneven ground 74 all of which may be wet and can even detect a ball 20 that is shallowly submerged in water, embedded in mud, or a short distance 76 below ground 74, e.g. : in a shallow burrow, covered by wet sand in bunker, or in hole on green.

Golf balls 20 used on courses are usually 2-piece or 3-piece construction. 2-piece is popular among ordinary recreational players, and while the 3-piece offers more control for the expert golfer. The 2-piece comprises an outer cover % and a solid (usually plastic) core, while the 3-piece consists of a solid rubber or liquid spherical inner core 24, layers of elastic winding upon this and then an outer cover 25. Whether for inclusion in a 2-piece or 3-piece ball 20, the transponder 22 needs to be small to occupy only the central region 24 of the ball 20 so that it does not interfere with the playing properties of the ball 20.

The transponder 22 contains a multi-turn loop antpnna 28 formed of wire, foil, conductive film or as t •a printed circuit, or in a combination of any of the foregoing composed of copper or any other suitable material (e.g. graphene). The antenna 28 is tuned to be resonant at the frequency of the excitation field 80 using an arrangement of capacitors 27. Fine adjustment of tuning at production can be facilitated by a variety of potential methods, which may be automated. The antenna 28 is connected to an electronic circuit 26 (an integrated circuit in a preferred embodiment), containing the means to rectify and step up (via charge-pump stages, or otherwise) the voltage available from the antenna 28 sufficient to energise and operate the other parts of the said circuit 26. These said other parts comprise: a means to create a modulation of the antenna 28 properties that would manifest a change in the re-radiation 90 of the excitation 80; containment of the information to generate a preconfigured signal pattern; means to generate and apply the said pattern to the said modulation means in endless unbroken repetition for as long as sufficient power remains available to the circuit; means to accept the preconfiguration information during production. By keeping the level of circuit 26 functionality to the minimum required to produce the requisite modulation, the power required by the integrated circuit 26 in the transponder 22 is minimised, so minimising the field strength required for the transponder 22 to function.

In a preferred embodiment of the said transponder 22, the diameter of the loop antenna 28 is between 10 and 15mm and the tuning capacitors 27, tuning adjustment means and integrated circuit 26 reside within the said antenna loop 28. In the said embodiment, the electronic elements are contained within strong rigid encapsulations 29A & 29B that are dimensionally and dielectrically stable with respect to variation in temperature and humidity. The said transponder is so arranged that when contained within the golf ball, the centre of mass of the ball is at the geometric centre of the ball 20, and so that the moment of inertia of the ball 20 is the same about any axis passing through the said geometric centre.

The finder device 40 consists of a number of elements: (1) a handle 42 for the user to grip; (2) a user interface 45 in close mechanical conjunction with the handle 42 providing relevant indications to the user 10; (3) a detection module 50 which produces the excitation 80 and performs return signal analysis; (4) a shaft 50, that may be fixed length or extendable/collapsible, separating the handle 42 and user interface 45 from the detection module 50, whereby the handle 42 and user interface 45 are at one end and the detection module 50 at the other.

As well as providing a suitable grip for the user 10, the handle 42 also has two switches 43 & 44 incorporated with it. Both switches 43 & 44 automatically default to 'off1, unless held 'on1. One switch 43 is the main control switch for the finder 40, and finder 40 will only operate while the said switch 43 is its 'on' state. The other switch 44 is a special-purpose override switch, the details concerning which which are elaborated further on in this description.

In a preferred embodiment these switches 43 & 44 would be buttons, with the main control button 43 ergonomically placed for ease of use and the override button 44 placed so that it may be accessed conveniently, but not easily pressed unintentionally, and main power switches for the finder 40 (primarily to prevent accidental operation when not in use) is separately placed at the detection module 50 and the user interface/handle 45/42.

The basic requirement for the user interface 45 is that it has 2-way communication with the detection module 50 and needs to indicate at least the following parameters: strength of return signal; battery status; system status (e.g. 'normal/ok' versus 'warning'). These parameters could be indicated any of the following: by visual signal; by auditory signal; by vibration of the handle 42; via a suitable application on a mobile phone, with communication via wi-fi, near-field communication, or by a plug-in cable; via a lightweight handset, with communication via wi-fi, near-field communication, other wireless link, or by a plug-in cable.

In a preferred embodiment of the finder 40, the user interface 45 signals to the user 10 via a set of bright indicator LED lights. To facilitate convenient viewing, the lights may be on a moveable element 46 that extends/pivots sideways from the body of the shaft/user interface 64/45 as part of the process of extending the shaft 64 for operating the finder 40. Alternatively the lights may be , t * t housed within the body of the shaft/user interface 64/45 and the said moveable element 46 may contain light-guides and/or mirrors so that the light signals appear at places on the said moveable element 46.

The detection module 50 includes: a battery 51 (rechargeable or otherwise); an optional power 52 switch; power conditioning 53; communications to the user interface 55; an excitation field coil 57 and driver module 56 for said coil 57; a detection coil 59 (if different from the excitation field coil 57); detection module 58 for the return signal 90; a control module 54 for managing the communications with the user interface 45, controlling the excitation coil driver circuit 56, and handling the output of the return signal detection module 58. In a possible embodiment, the said excitation field coil 57 and detection coil 59 would fold out when the shaft is extended for operation, in a further embodiment there may be a sequentially-driven multiplicity of excitation field coils 57, for a multiplicity of orientations of the flux of the excitation field 80, in order to reduce the variability in the excitation of the golf-ball 20 due to the orientation of the said ball 20. The elements 51-59 of the detection module 50 are contained within a protective containment or containments and in a preferred embodiment these containments are waterproof. A possible embodiment of the finder has the strength of the excitation field 80 variable in dependence of a manual or automatic control.

Communication between the detection module 50 and the user interface 45 over the length of the shaft 64 may be implemented in various ways: via a single wire or wires internal or external to the shaft 64 ; via a radio link; via ultrasonics; via optical fibre internal or external to the shaft 64; or, in a preferred embodiment ,via an optical link 65 (at infra-red, visible or ultra-violet wavelengths) internal to the shaft 64, passing through the space of the hollow interior of the shaft and reflected by the internal faces of the shaft. Given an extendable shaft 64, with repeated extending and collapsing in repeated use of the finder 40, an inexpensive wired link would have potential for mechanical degradation and consequent risk of failure, whereas a wireless link would avoid this said risk and simplify product assembly. Aside from a probable cost advantage and reliability advantage, an optical link 65 facilitates other functional aspects discussed further on. A wireless linkage between the detection module 50 and the user interface 45 requires the user interface to have its own battery..

The shaft 64 in a preferred embodiment is of tubular construction, and in a further preferred embodimant comprises in its main aspect a telescopic set of hollow tubes 68 which can be extended or collapsed to adjust its length accordingly for operation or stowage.

The shaft 64 serves a number of purposes. The first purpose is to extend the effective detection range of the finder 40, so that if, for example, the finder 40 can detect a golf-ball 20 2 metres in any direction from its excitation antenna 57, with a shaft 64 extended to 1.5m length and due allowance for the handle 42 and the comfortable reach of the average user 10, a range from the user 10 of 4.2m may be obtained. A further purpose is to diminish the level of strength of the excitation field 80 that the user 10 is exposed to, thereby enabling the excitation field 80 generated to be stronger and/or the duty cycle of the said field 80 to be increased for improved detection.

Further, the shaft 64 improves the convenience and ergonomics of homing in on a ball 20 that the user 10 has been able to come dose to, but is still unable to see, typically because of the nature of the rough in which the ball 20 is located, or because of being covered, or embedded in soft ground. The detection module 50 on the far end of the shaft 64 can be moved around in the general vicinity of the ball 20 seeking a maximum return signal 90 signifying that the end of the shaft 64 is within a few centimetres of the ball 20, while the user 10 remains in a reasonably comfortable standing position.

Further still, the shaft-based format of the finder 40 makes it convenient to stow the said finder 40 i •. in a golf-bag in the club-compartment among the clubs, and also to conveniently retrieve the said finder 40 from the said compartment.

In order to maximise detection performance while keeping the exposure to the excitation field 80 of the user 10 within recommended limit at the frequency of operation, various exposure mitigation and protection measures are employed. The first measure is, as already mentioned, to remove the excitation field 80 source 57 from the user 10 by virtue of the length of the shaft 64, which reduces the peak intensity of the RF field 80 at the user 10.

The second measure is to limit the duty cycle of the excitation field 80 so that the average RF power incident upon the user 10 is within the said recommended limit. In a preferred embodiment the duty cycle is adjustable according to the length of the shaft 64 (automatically or otherwise), so that with a greater length a higher duty-cycle is permitted, which in turn facilitates searching while the detection module 50 antennas 57 & 59 move over the terrain at a faster speed consistent with sweeping with a longer shaft 64. In order to determine the appropriate duty cycle as the length of the shaft 64 is varied, one method is for the user interface 45 to sense the level of the excitation field 80 at that point and feed back to the detection module 50.

Thirdly, the excitation field 80 is only able to be produced when the shaft 64 is at least extended to a minimum operating length. If an internal optical link 65 is used in the shaft 64 then the minimum extension of the shaft 64 can be detected via the said optical link 65 if this results in the removal or opening of a physical obstruction to the optical signals 65, to enable operation of the optical link 65 only when the shaft 64 is correctly extended.

Fourthly, the excitation field 80 is only generated when the handle 42 is being held (for the main switch 43 at the handle to be operated) provided the shaft 64 is extended to at least its minimum operating length; if the shaft 64 is not sufficiently extended, a warning is signalled to the user 10 by the user interface 45.

Further measures are designed to ensure that the detection module 50 is away from other persons when it operates, and can include: detection of tilt, so that the excitation-field 80 is only generated when the shaft 64 is angled towards the ground and so thereby not towards the trunk or head of any persons; ground proximity detection, perhaps by a low-power microwave sensor, so that the excitation-field 80 is only generated when the antenna assembly 57 & 59 is near the ground and so not near the trunk or head of any persons; detection of proximity to person(s), possibly by a low-power microwave proximity detector located near to the excitation antenna 57. When any of these measures detects a non-permitted state during attempted use, the user interface 45 signals a warning to the user 10.

Given that circumstances will arise when a non-permitted state is detected in error (e.g. the person-proximity detection responds to a substantial object that is not a person) or the detection module 50 is desired to be used away from the ground, an override function is provided via the special-purpose override switch 44 at the handle. To prevent routine use of the override function, in a preferred embodiment, the said function will only be accessible when a warning is being signalled, and attempted use at other times will inhibit operation; furthermore, once accessed, the function will only remain in operation for a limited time, after which it will need to be re-accessed.

Claims

Claims CLAIM 1 A system for locating missing golf balls comprising a golf ball that contains a passive RF transponder (i.e. an RF transponder with no power supply source within the ball) and a finder that emits an excitation signal and receives a return signal from the ball; the system characterised by operating with RF signals in the HF band for operation tolerant of rough and wet terrain (including under water), with the excitation signal unmodulated so that a strong signal may be emitted within a narrow frequency allocation, and with near-omnidirectional detection: the transponder comprising an antenna made resonant at the frequency of the excitation signal and a circuit that is powered by and modulates the radio-frequency properties of the antenna; the transponder, in the presence of a sufficient unmodulated excitation field at the resonant frequency, producing a continuous repeating modulation of its re-radiation of said excitation according to a preconfigured pattern to manifest the presence of an RF signature in the form of signal-level in a sub-band of said re-radiation, detectable by a suitable receiver circuit; the transponder embedded and entirely contained within and concentric with a solid central core to the golf ball; the finder comprising a shaft (fixed length or extendable/collapsible), having one end attached to a user handle and user interface arranged with control actuation means and means to signal to the user, having the other end of said shaft attached to a detection module, and having means, by wires or otherwise, of communication of signals and transferring power between the ends of said shaft; the said detection module comprising a circuit, emission antenna and reception antenna, where the antennas may be separate or in combination, and protective containments for the respective parts; the arrangement of the finder being such that the maximum distance from the user at which a ball may be detected is extended by virtue of the length of the shaft; the arrangement of the finder also being such that by virtue of its elongated format it is convenient and ergonomic for a user who is standing to bring the detection module antennas to the immediate location (e.g.within 10cm) of the ball even in places of obstructed visibility, and it is also convenient and ergonomic to stow the said finder in, carry in and retrieve from the clubs compartment of a golf-bag; the arrangement of the finder further being such that the exposure of the user to the excitation field is mitigated through the extended physical separation afforded by virtue of the length of the shaft. CLAIM 2 A finder as in claim 1, wherein there is a plurality of emission antennas that may be arranged with different orientations, and there is either one reception antenna, or plurality of reception antennas that may be arranged with different orientations. CLAIM 3 A finder as in any of the preceding claims, wherein the shaft is collapsible to a very short length to provide additional stowage/portability options. CLAIM 4 -. A finder as in any of the preceding claims, wherein the shaft is of tubular construction. CLAIM 5 A finder as in any of the preceding claims, wherein the shaft is in the form of a telescopic set of tubes. CLAIM 6 A finder as in any of the preceding claims, wherein the user interface would provide any of the following indications: signal strength indication, finder battery status, finder operation status. CLAIM 7 A finder as in any of the preceding claims, wherein the strength of the excitation field is manually variable. CLAIM 8 A finder as in any of the preceding claims, wherein there is no wired connection between the ends of the shaft and hence there are separate power sources at each end: with a short-range radio link between ends of the shaft; or, with an ultrasonic link between ends of the shaft; or, with an optical link between ends of the shaft routed externally or internally to the shaft, via fibre; or, with a through-air optical link between ends of the shaft routed through the internal space of the shaft. CLAIM 9 A finder as in any of the preceding claims, as applicable, with additional mitigation measures re human exposure to the strong RF excitation field source, that include any of the following :- (1) a low duty cycle for the excitation field so that the average RF power incident upon the user is within recommended limits; (2) the said duty cycle is adjustable according to length of shaft (automatically or otherwise), so that with a greater length a higher duty-cycle is permitted, which in turn facilitates searching while the detection antennas move over the terrain at a faster speed consistent with sweeping with a longer shaft; (3) in order to determine the appropriate duty cycle or strength of excitation field in accordance with the length of shaft, the strength of excitation field at the handle/user inerface is measured by a circuit at the handle/user interface; (4) detection of tilt, so that the excitation-field is only generated when the shaft is angled towards the ground and so thereby not towards the trunk of any persons, optionally with a temporary override function when searching is desired at some distance above ground; (6) ground proximity detection to so that the excitation-field is only generated when the antenna assembly is near the ground and so not near the trunk of any persons, optionally with a temporary override function when searching is desired at some distance above ground; ' ί * (7) detection of proximity to person(s), by a low-power microwave proximity detector located near to the excitation antenna or other means, optionally with a temporary override function for when proximity detection is erroneous; (8) the excitation field is only generated when the handle is being gripped (e.g a button in the handle is pressed), optionally with the additional condition that shaft is extended to at least a minimum operating length; (9) if an internal optical link is used in the shaft then the minimum extension of the shaft is detected via the said optical link whereby sufficient extension results in the removal or opening of a physical obstruction to the optical signals, to enable operation of the optical link only when the shaft is correctly extended.