GB2113102A - Golf stroke monitoring apparatus - Google Patents

Abstract

Apparatus (10) for monitoring a golfer's golf stroke comprises a display panel (11) having face indicators (12) thereon. Indicators (12) are indirectly driven by sensor devices (20A, 20B, 20C) located in the vicinity of a position (22) arranged to locate a golf ball. Each sensor device is electrooptic being optically influenced by the passage of a golf club head thereover and the electrical output drives a data handling circuit which generates a measure of the speed and face angle of the club head at position (22), indicators (12) displaying such measures. <IMAGE>

Description

SPECIFICATION Golf stroke monitoring apparatus This inventio relates to the game of golf and in particular to golf-stroke monitoring apparatus.

According to the present invention there is provided golf-stroke monitoring apparatus comprising means forming an artificial golfplaying surface incorporating a device for locating a golf ball at a predetermined position on said surface and a plurality of sensor devices mounted on said means at fixed locations with respect to said predetermined position, said sensor devices being respectively adapted to generate signals indicative of the passage thereover of a golf club head, and data-handling means coupled to each of said sensor devices and adapted to provide at least a read-out of club head face angle during travel of a club head through said predetermined position from the signals generated by said sensor devices.

Preferably said sensor devices are three in number, the first of said three sensor devices being located in alignment with said predetermined position but spaced longitudinally therefrom along the expected line of club-head travel through said predetermined position and in advance of said predetermined position. The second of said three sensor devices in this arrangement is laterally offset in one direction from the expected line of club-head travel and aligned with the predetermined position and the third sensor device is aligned with the second sensor device but laterally offset from the club-head line of travel in the opposite direction to that of the second sensor device.In this arrangement the datahandling means can be arranged to provide a read-out of the angle of the golf club face travelling through the predetermined position according to the relative timing of the signals generated by the second and third sensor devices, and can additionally be arranged to provide a read-out of the club head speed traversing the predetermined position.

Conveniently when the apparatus is in operation the first of said three sensor devices is permanently enabled and the signal generated thereby by a passing club head is used to enable the second and third sensor devices for a predetermined time interval. With this arrangement the power consumption of the apparatus is restricted.

Conveniently the data handling means comprises a data memory which is addressed by signals representative of the time difference between the signals generated by the second and third sensor devices and by a signal representative of club head speed, the data memory output being thereby quantitatively indicative of the club head angle.

In an alternative arrangement said sensor devices are four in number and arranged in pairs respective sensor devices of each pair being laterally offset in opposite directions from the expected line of club head travel through said predetermined position, the first of said pairs being in advance of said predetermined position and the second of said pairs being aligned with said predetermined position. in this airangement the data handling means can be arranged to provide a read-out of the angle of the golf club face travelling through the predetermined position according to the relative timing of the signals generated by the sensor devices of said second pair.Conveniently in this arrangement all four sensor devices are permanently enabled and the relative timing of the signals issued by one of the sensor devices of each pair is representative of club head speed.

The sensor devices may take any one of a number of forms depending upon the sensitivity desired. For example each sensor device may simply be a photo-transistor which is activated when ambient light is cut off by the undersurface of the golf club head as it traverses the phototransistor. Preferably however each sensor device is formed by a radiation emitter and receptor pair operating at a predetermined wavelength. It is preferred that the wavelength is in the infrared band. The receptor may be protected by an ambient filter stop.

The means forming the artificial golf-playing surface may take any convenient form but preferably comprises a base panel of rigid plastics material overlaid with an imitation grass fabric, the sensor devices being housed in apertures formed in the base panel and the golf-ball locating device being formed in the base panel, for example in the form of an aperture for holding a peg tee. Conveniently the data-handling means is carried by a support resiliently connected to the base panel so that impacts thereon caused by use of the apparatus are not transmitted to the datahandling means. Alternatively the data-handling means may be supported separately from the base panel, signal transmission being by way of a cable.

Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings in which: Fig. lisa diagrammatic representation of the apparatus according to the present invention; Fig. 2 schematically shows an electrical circuit forming part of the apparatus of Fig. 1; Fig. 3 is useful in understanding the operation of the apparatus; and Fig. 4 illustrates an alternative circuit to that of Fig. 2 for use with apparatus having four sensor devices.

Fig. 1 is a purely diagrammatic representation of apparatus 10 for monitoring a golfer's golf stroke. The apparatus comprises a display panel 11 on the face of which are provided various indicators 12. The various indicators 1 2 fulfil individual functions and are respectively associated with an appropriate legend 1 3. Panel 11 (which may be surrounded by a cowl to improve visibility in high ambient light) is connected to a plinth 1 5 formed by a base panel of rigid plastics material (not shown) overlaid with an imitation grass fabric 1 6 and houses three sensor devices 20A, 208, 20C, fixedly located on the plinth 1 5 with respect to a pre-determined position 22 at which there is provided a device, conveniently in the form of an aperture, for holding a peg-tee so that a golf ball 21 or practise golf ball can be located at position 22 and struck by a golf club head travelling in the direction of the arrows A.

Each sensor device 20A, 208, 20C, incorporates an electro-optical element the electrical output of which is fed to a data handling circuit 25 shown in block form in Fig. 2. This circuit 25 is capable of calculating the angle of the club head face during the travel of the club head in the direction of arrows A and adjacent position 22 and depending on the orientation and the magnitude of this angle selected ones of the indicators 12 in display panel 11 are illuminated.

Furthermore circuit 25 is capable of determining the club head speed as it traverses position 22, the result of which is displayed in a further indicator 12 which is in the form of a segmented LED read-out 12A.

The operation of circuit 25 is as follows. When the apparatus is switched on the 9 volt power supply is applied to the clock generator and power clear-up unit 25A which resets all the bistables in units 258, 25C, thereby causing circuit 25 to enter a waiting state. Sensor device 20A is directly energised by switching on of the power supply whereas sensor devices 20B, 20C are not. When a club head traversing path A is sensed by sensor device 20A the electrical output signal generated by device 20A is fed to speed counter 25D of circuit 25 which commences counting down from a high present value.At a fixed time interval later, conveniently 500 ,us, sensor devices 208 and 20C are enabled so that these sensor devices are enabled sufficiently early to detect the passage thereover of a club head travelling at the maximum anticipated speed produced by a golfer.

This delay in enabling sensor devices 20B, 20C, restricts the power consumption of the apparatus.

A further restriction in power supply is achieved by delaying energisation of the latches 25E which receive the outgoing electrical signals from sensor devices 208, 20C, and it is preferred that this further delay is of the order of 7 ms.

When the first or both of sensor devices 20B, 20C detects the club head passing thereover speed counter 25D is stopped and the result transmitted to the LED read-out 1 2A via a BCD/7 segment decoder 25F. In the event that the speed counter 25D has counted down to a low present value prior to the first or both of sensor devices 208, 20C detecting the club head counter 25D is stopped and reset to its initial state without driving the decoder 25F and accordingly without providing a visible legend in LED read-out 12A.

Conveniently this low preset value is equivalent to a club head speed of only 1 9 mph which is very much less than would be expected from the golf club swung by a golfer in normal manner.

However this inhibition of read-out 1 2A facilitates use of the apparatus to practice a golfer's putting stroke in which case club head speed is of no significance.

In order to determine club face angle circuit 25 incorporates a pre-programmed read only memory (ROM) 25G which is addressed by speed counter 25D and angle counter 25H, the latter being connected to latches 25E and operating to determine the order and time interval between sensor devices 208 and 20C detecting the club head. The club face angle is obtained from the preprogrammed lookup table of the ROM 25G and the output thereof is applied to bistables 25C to illuminate, in combination with bistables 25B, the appropriate indicators 1 2.

This arrangement of calculating club face angle is dependent on the geometry of the system as indicated in Fig. 3 from which it will be seen that the club head face angle 0 would be O if sensor devices 20B, 20C simultaneously detected the club head whilst for non simultaneous detection tan 0 = the ratio of distance X to distance Y.

Distance Y is predetermined by the location of sensor devices 208, 20C whereas distance X is a function of the time interval between detection of the club head by sensor devices 20B, 20C and the club head speed.

To simplify programming of the ROM 25G the club head face angle 0 is only indicated on display panel 11 to within an angular range, namely 3--60 or 6--100 or 10--1 50 or greater than 15 . Furthermore the order of operation of sensor devices 20B, 20C is indicative of whether the club head face is open or closed, that is whether angle o in Fig. 3 is positive or negative and this is indicated on the appropriate indicator 12 in display panel 11 by operation of the bistables 25B.In the extreme case where the intended line of travel of the club head intercepts the location of sensor device 20A and only one of sensor devices 20B, 20C, this is indicated by the appropriate indicator 1 2 in panel 11 by means of the bistables 258. Thus sensor device 208 detecting the club head in the absence of sensor device 20C would illuminate indicator 12 associated with the "heel" legend 1 3 and sensor device 20C detecting club head in the absence of sensor device 20B doing likewise would illuminate the indicator 12 associated with the "toe" legend 1 3.

In order to minimise drain on the battery power source circuit 25 is arranged to restrict the duration of operation of the indicators 12 in panel 11. Conveniently the illumination is limited to less than 10 seconds.

Sensor devices 20A, 20B, 20C, previously mentioned are preferably formed by a radiation emitter and receptor pair. An infrared emitter is provided by an ITL 32 device and an infrared receptor by an MEL 12 device. Alternatively the emitter may be a CQY36N and the receptor a BPW16N. It will be appreciated that it may be necessary for amplifiers to be provided between the output of the sensor devices and the latches 25E of circuit 25.

The plinth 1 5 which preferably incorporates a rigid plastic base panel conveniently supports the printed circuit board incorporating the sensor devices 20A, 20B, 20C, this board being provided with conventional edge connectors to facilitate connection of the sensor devices to the logic circuit 25 which is preferably remote from the predetermined position 22 on surface 1 6 thereby to isolate circuit 25 from the effects of the golf club head impact on the golf ball 21. The position 22 may simply be formed by a circular hole to accommodate a peg-tee but the hole may be elongated in the direction of the arrow A at least to a limited extent since precise positioning of sensor devices 208, 20C relative to the golf ball 21 is not overly critical in operation of the apparatus.

It will be understood that the angular range of angle 0 which is displayed need not be as previously identified. For example it may be found more meaningful to separate the angular range into the following steps: 030, 370, 7130, 13--200, > 200 and of course the data handling means must be programmed accordingly.

Furthermore at least the LEDs 12 which denote club face angle may conveniently take elongated form mutually orientated to illustrate visually the club-face angle. In this case zero angle club face would be vertical whilst the open and closed club face angles would be angularly offset on opposite sides therefrom.

The arrangement illustrated in Fig. 4 is similar to that of Fig. 2 but is arranged to operate with four sensor devices 30A, 31A, 30B, 30C, where sensor devices 30A and 31 A replace sensor device 20A of Fig. 1 laterally offset in opposite directions from the line A whilst sensor devices 308 and 30C are located in the same positions as devices 208, 20C respectively. With this arrangement the signals from sensor devices 30A, 31A are delivered to speed counter 25D which, on receipt of the first such signal counts down from its preset high value until it is stopped by the first signal arising from sensor devices 308, 30C via the latches 25E which were previously enabled by counter 25D.If a time interval of more than about 500 ms is exceeded the counter 25D is reset without issuing a signal to display 1 2A as being indicative of a putting stroke where club head speed is of no concern. In its normal operation counter 25D drives binary counter 25J to count down from 1 5 (with the 1 Os clock of counter 25D). When counter 25D is stopped counter 25J contains a number representative of club head speed. Counter 25J controls the frequency output of binary rate mutliplier 25L which in turn controls a decade counter 25K only during the time interval between the sensor devices 30B and 30C issuing output signals so that counter 25K represents club-face angle and the output thereof operates display drivers 25C as previously.

It will be understood that the sensor devices need only be spaced apart by a distance which is of the order of the diameter of a conventional golf ball and that there is no requirement for any substantially greater spacing between the various sensor devices. By way of a specific example relating to Fig. 4 devices 30A and 31 A may be mutually separated by a distance of 1.75 inches.

Sensor devices 30B and 30C may also be mutually separated by a distance of 1.75 inches.

Devices 30A, 31 A, may be separated along the expected line of travel of a golf ball head by a distance of 2.0 inches from the devices 308, 30C.

As is known the diameter of a conventional golf ball is 1.62 inches (British standard) or 1.68 inches (U.S. standard).

Claims (7)

1. Golf-stroke monitoring apparatus comprising means forming an artificial golf-playing surface incorporating a device for locating a golf-ball at a predetermined position on said surface and a plurality of sensor devices mounted on said means at fixed locations with respect to said predetermined position, said sensor devices being respectively adapted to generate signals indicative of the passage thereover of a golf club head, and data-handling means coupled to each of said sensor devices and adapted to provide at least a read-out of club head face angle during travel of a club head through said predetermined position from the signals generated by said sensor devices.

2. Apparatus as claimed in claim 1 , wherein said plurality of sensor devices includes two sensor devices which are mutually separated in the direction of the expected line of club-head travel and the data-handling means is arranged to provide a read-out of club head speed from the relative timing of the signals generated by said two sensor devices.

3. Apparatus as claimed in claim 2, wherein said plurality of sensor devices further includes two sensor devices which are mutually separated laterally of the expected line of club-head travel and said plurality is three in number.

4. Apparatus as claimed in claim 2, wherein said plurality of sensor devices further includes two sensor devices which are mutually separated laterally of the expected line of club-head travel and said plurality is four in number.

5. Apparatus as claimed in any preceding claim, wherein each said sensor device comprises a radiation emitter and receptor pair operating at a predetermined wavelength.

6. Apparatus as claimed in claim 5, wherein said wavelength is in the infrared band.

7. Golf-stroke monitoring apparatus substantially as hereinbefore described with reference to any one of the embodiments illustrated in the accompanying drawings.