GB2091111A

GB2091111A - Mechanical aid

Info

Publication number: GB2091111A
Application number: GB8200594A
Authority: GB
Original assignee: TREDINNICK STEPHEN VISTOR
Current assignee: TREDINNICK STEPHEN VISTOR
Priority date: 1981-01-19
Filing date: 1982-01-08
Publication date: 1982-07-28

Abstract

A mechanical aid apparatus is for assisting the striking of a target with an implement, particularly a golf ball 4 with a golf club 5. An array of transducer elements 7, 8, 9 is provided in a strike mat 6 for measuring the approach of the club to the ball on a tee 18. A servomechanism moves the ball to meet the club head 5 in accordance with the measurements from the transducer elements. <IMAGE>

Description

SPECIFICATION Mechanical aid The invention relates to a mechanical aid to assist the striking of a target with an implement. It is particularly suited to the assistance of striking a golf ball with a golf club. However other uses are envisaged both in sports activities and in non-sporting activities.

When a target such as a golf ball is struck by an implement such as a golf club, there is a spot on the implement which gives the most satisfactory blow to the target. In golf, this spot is known as the sweet spot. Striking the ball with the sweet spot on the club has two closely related effects. Firstly, the ball flies well. Secondly, the shot feels good to the golfer.

It is believed that this good feeling is caused by the absence of any twisting or bending of the golf club shaft, as is present when the ball is not struck at the sweet spot. Further, it is believed that when the ball is struck at the sweet spot, the point of impact is aligned with a line connecting the centre of gravity of the ball and the centre of percussion of the ciub.

When the point of impact is displaced from the sweet spot, the force imparted to the ball will not act along the line connecting these centres and the club head will tend to be angularly deflected from the desired squareness to the ball. This deflection is felt at the grip as an unpleasant reaction, causes a deflection of the ball from the intended flight and absorbs energy which would otherwise be imparted to the ball.

Various previous devices have been produced for aiding golfers in analysing their swing. In particular the Acushnet Company have produced a swing analyser which is described in their US Patents Nos.

4063259 4137566 4160942 4132462 4148096 4136387 4158853 This swing analyser records a golfer's swing and the initial flight of the ball. (As an additional feature it predicts the flight of the ball, thus enabling the equipment to be used indoors and the predicted flight two be projected onto a screen through which the ball is driven). Should the golfer using this swing analyser mis-hit the ball, i.e. in fact not strike the ball on the sweet spot of the club, the fact will be recorded and the swing may be analysed in an attempt to discover what has gone wrong. The golfer may then attempt to correct the fault in his next shot, but there is no guarantee of him getting it right.Until he does by perseverance get it right, he will not experience the feeling of hitting the ball on the sweet spot, i.e. he will not experience the absence of twist at the grip, and he will not get the pleasure of making a good shot.

The approach of the present invention is to move the ball to suit the golfer's swing so that the golfer experiences the pleasant feeling of hitting on the sweet spot even though the ball would not have been hit on the sweet spot had the ball not been moved. Then to improve his play the golfer adjusts his swing to reduce the movement of the ball which was required to hit on the sweet spot. The invention is not restricted to use in this manner. For instance, apparatus of the invention might be programmed for the ball to be struck off the sweet spot. This enables, for example, the position of the sweet spot on a par ticular club to be established or the golfer to assess the feeling of hitting off the sweet spot so that in play he can gauge how far off the sweet spot he is playing and so make the necessary corrections to bring his play back to form.

The mechanical aid apparatus of the invention comprises means for measuring an implements's movement towards a target and means for moving the target to meet the implement.

In another aspect of the invention there is provided a method of assisting the striking of a target with an implement, the method consisting in the steps of: measuring the movement of the implement towards the target; predicting the point of striking of the target; and moving the target to the predicted point of striking of the target.

A variety of measuring means are envisaged.

The measuring means may include one or more arrays of transducer elements, such as photoelectric cells or capacitive proximity detectors. Such an array will primarily give information astro the presence or absence of the implement in a binary mode, though it may operate to a secondary extent in an analogue mode. For example, where the apparatus is for aiding golf and the array comprises a row of photoelectric cells, they will only register the presence or absence of the club head above them according to whether or not they receive light, which may be ambient or artificial. Alternatively, where the array comprises a horizontal row of capacitive proximity detectors, the closeness with which the club head passes over an individual detector may be assessed.

Thus the instanteous position of the club head may be measured in three dimensions.

To give an improved prediction of the position of the club when it strikes the ball, it is preferable to measure the instanteous position of the club head at two discrete points in the swing. Thus account can be taken of any angular misalignment of the swing from the norm.

Continuity of measurement is limited when an array of transducer elements is used, since the position of the club head can only be determined when it is at one of the elements. It is envisaged that the position of the club head may be tracked continuously by for instance the use of an electro-optical sensing system. It may be necessary to provide artificial light, to enhance the reflectivity of the club and to use a higher than usual refresh frequency. Alternatively, the club head may be provided with a light-emitting diode, which may be pulsed to facilate recognition of its image in the camera.

By using continuous tracking and to a lesser extent by using a plurality of row-arrays, or indeed a two dimensional array, of transducer elements, it is pass ible to monitor the movement of the club h?ad over an appreciable proportion of the swing. In particular, monitoring of the early part of the swing may give a rough estimate of the amount by which the moving means has to move the target, e.g. a golf ball, whereas fine adjustment is only possible from measurement of the club head during its final approach to the ball. To effect such dual measurements, photographic monitoring may be employed for the early part of the swing and an array or arrays of transducer elements may be employed for the final approach.Such an arrangement may enable the moving means to make substantial movements for which there would not be time if they had to be made entirely during the final approach. For such combined monitoring, it is not in fact necessary for a combination of continuous and discrete monitoring to be employed. Radar might be employed for the entire monitoring operation ortwo sets of arrays could be employed, one half-way down the swing and the other during the final approach.

Where the target is a golf ball, the moving means includes a servo-mechanism and a tee which is movable by the servo-mechanism and adapted to hold the ball for rapid movements transverse to the direction of striking of the ball. The servomechanism may be an electro-hydraulic or electropneumatic actuator or it may be an electro-magnetic induction device. The tee may be adapted to hold the ball by releasable means such as a vacuum or it may have hinged-down fingers abutting each side of the ball which hinge down on striking of the ball.

To help understanding of the invention, various specific embodiments will now be described with reference to the accompanying drawings in which: Figure lisa perspective view of a golfer using a mechanical golfing aid according to the invention, Figure 2 is a plan view of the strike mat of the mechanical golfing aid of Figure 1, Figure 3 is a diagrammatic view of the connections to the control unit of the mechanical golfing aid of Figure 1, Figure 4 is a side view of the servo-mechanism of the mechanical golfing aid of Figure 1, Figure 5 is a perspective view of another mechanical golfing aid of the invention, and Figure 6 is a perspective view of a third mechanical golfing aid according to the invention.

Referring nowt the drawings, Figure 1 shows a golfer 1 holding a club 2 during a swing to hit a ball 4 with the club head 5. A strike mat 6 has three row arrays 7,8,9 of transducer elements 10 set in it, up-strike of the ball. In the first row 7, the transducer elements 10 are photoelectric cells, activated by ambient light (Artificial overhead light may be used if the ambient light is insufficiently intense). The transducer elements feed information as to which of them was switched off by the passage of the club head over them to a control unit 11. Usually the element furthest from the golfer which is switched off will be regarded as the critical element since the handle 12 of the club may switch off various nearer s!3;nents as well as those switched off by the passage over head of the club head.

The critical element will give an indication of where the sweet spot 13 on the club face will pass over a tee slot 14 in the strike mat 6. It should be noted that different golfers will have different swings, thus the same critical element being switched off for different golfers will not necessarily indicate that the sweet spot will pass over the tee slot 14 at the same place. The control unit 11 may be made capable of being programmed to take account ofthe difference by remembering the angle a of approach (see Figure 2) which the golfer's previous swing 15 made to an ideal swing 16. The angle of approach may be set manually or calculated by the control unit.For this purpose a further row 17 of photoelectric cells may be provided in the strike mat "down-strike" of the ball. This row may also be used to monitor whether the golf-club head actually passed the tee slot 14 at the predicted place. The ele ments in row 17 are connected to a memory 17a in the control unit.

The transducer elements in the row 8, which is closer to the tee slot 14 than the row 7, are also photoelectric cells. A different element may be the critical element on this row when the club head passes overhead, if the angle of approach of the swing is large. The information as to which is the critical element in row 8 is fed to the control unit to enable itto more accurately predict the place at which the sweet spot 13 will cross the tee slot.

The ball 4 is supported at the slot by a tee 18 which is positioned by a servomechanism 19 under the control of the control unit 11. As soon as the club head passes the first row 7, the servo-mechanism begins to move the ball to the place at which the sweet spot is predicted to pass over the tee slot 14, the place being predicted in accordance with whichever is the critical element and the memorized angle of approach. As soon as the club head passes the second row the prediction is refined.

The advantage of utilizing a remembered angle of approach is that movement of the ball can be started as soon as the first row 7 is passed. However it should be noted that the feature of remembering the angle of approach may be dispensed with and the second row 8 utilized to assess the angle of approach. In a much simpler alternative only a single row of transducer elements may be used and the angle of approach is assumed to be normal.

The third row of transducer elements are proximity detectors for measuring how high the club head 5 is passing over the strike mat 6. These height measuring transducers are as near to the tee slot 14 as possible, consistent with the servo-mechanism having time to move the ball to meet the sweet spot, since the height of the club head is continually varying along its curved trajectory. As with the other rows 7,8 information is fed from certain of the elements over which the club head passes to the control unit which in turn controls the servomechanism to move the ball to the predicted height of the sweet spot at the tee slot. As may be seen in Figure 3, the transducer elements in rows 7,8 are connected to a "horizontal movement" portion 20 of the control unit which in turn controls a "horizontal movement" por tion 21 of the servo-mechanism.Similarly the transducer elements in row 9 are connected to a "vertical movement" portion 22 of the control unit which in turn controls a "vertical movement" portion 23 of the servo-mechanism. However, the transducer elements in row 9 are also connected to the "horizontal movement" portion 20 of the control unit, to give further refinement of the predicted place at which the sweet spot passes the tee slot 14.

In an alternative embodiment, the second row 8 of transducer elements may be dispensed with and the row 9 of transducer elements utilized for both vertical and horizontal measurements.

The servo-mechanism 19 is shown in more detail in Figure 4. The horizontal movement portion consists of an electro-hydraulic actuator 24 having a horizontal control rod 25 which is moved under control of the horizontal movement portion 20 of the control unit. The remote end of the control rod is connected to the vertical movement portion consisting of a further electro-hydraulic actuator 26 having a vertical control rod 27. The actuator 26 is mounted on slides 28 for bodily movement by the actuator 24.

The control rod 27 extends through the tee slot 14 in the strike mat 6, and is in effect the tee. A cradle 29 of touch plastics material weakened at 30 to enable it to hinge down when struck by the club head holds the ball.

In operation, the arrays 7,8 measure the horizontal approach of the club head and the control unit controls the actuator 24 to move the ball 4 accordingly.

Similarly the array 9 measures the vertical approach of the club head and the control unit controls the actuator 26 to move the ball accordingly. Thus the ball is moved to meet the approaching club head with the sweet spot of the club striking the ball.

Figure 5 shows an alternative embodiment wherein the measuring means is an electro-optical system 31, including a pair of television cameras 32, 33, which can monitor the entire swing of the club head 5 and feed information to the control unit 11 for controlling the servomechanism 19 in a similar manner to the previous embodiment. One camera 32 is positioned behind the club head 5 as it approaches the ball 4. This camera measures both the height of the club head and its horizontal deviation from the ideal swing. The other camera 33 is positioned on the opposite side of the swing from the golfer to measure progress of the swing so that the three dimensional position of the club head can be measured during approaches to the ball. Thus the angle of approach may be computed in the control unit 11 and the servo mechanism controlled to move the ball 4 to meet the sweet spot 13.

To enable the cameras to distinguish the club head, it is provided with enhanced reflectivity tape 34 fixed to it. It is anticipated that the club head may be moving at speeds in excess of 160 km. per hour (100 mph) on striking of the ball and that the club will be tracked for the preceding 50 milliseconds. To obtain a significant number of measurements, the cameras may be operated at a refresh frequency higher than the usual 50 Hertz.

Figure 6 shows another alternative embodiment using an alternative electro-optical sensing system.

Again two cameras 35,36 are used. The club head is equipped with one or more light emitting diodes 37.

These are pulsed by a pulsing circuit connected to the cameras to enable them to recognise the light emitting diode(s). Such a system is available in the SelcomiTrack kinematic acquisition system. A row 38 of transducer elements is provided in the strike mat 6 to enable final fine adjustment of the position of the ball to be mada In this embodiment, the ball 4 is retained on the tee 18 prior to striking by a vacuum applied from a vacuum pump 39, the tee being hollow.

With all the above described embodiments, the control unit 11 feeds the control signals not only to the servo-mechanism 19 but also to a printer 40 which prints out details of how much the ball was moved from the ideal position to meet the sweet spot.

The invention is not intended to be restricted to the above described embodiments. tor instance electro-magnetic servomotors could be used in the servo-mechanism.

Claims

1. Mechanical aid apparatus for assisting the striking of a target with an implement, the apparatus comprising: means for measuring movement of the implement towards the target, and means for moving the target to meet the implement.

2. Mechanical aid apparatus as claimed in Claim 1 wherein the measuring means comprises means for continuously measuring the movement of the implement.

3. Mechanical aid apparatus as claimed in Claim 1 wherein the measuring means comprises means for discretely measuring the movement of the implement at at least one discrete position.

4. Mechanical aid apparatus as claimed in Claim 1 wherein the measuring means comprises means for measuring the movement of the implement both continuously and discretely.

5. Mechanical aid apparatus as claimed in Claim 2 or Claim 4 wherein the continuous measuring means is adapted to measure the trajectory of the implement in three dimensions.

6. Mechanical aid apparatus as claimed in Claim 2, Claim 4 or Claim 5 wherein the continuous measuring means is a radar apparatus.

7. Mechanical aid apparatus as claimed in Claim 2, Claim 4 or Claim 5 wherein the continuous measuring means is an electro-optical sensing system.

8. Mechanical aid apparatus as claimed in Claim 7 wherein the implement is provided with enhanced reflectivity material for aiding recognition of the implement by the electro-optical sensing system which comprises television cameras operating at a high refresh frequency.

9. Mechanical aid apparatus as claimed in Claim 7 wherein the implement is provided with a pulsed light-emitting diode for aiding recognition of the implement by the electro-optical sensing system.

10. Mechanical aid apparatus as claimed in Claim 3 or Claim 4 wherein the measuring means com prises at least one discrete row array of transducer elements arrayed across the path of movement nf the implement towards the target.

11. Mechanical aid apparatus as claimed in Claim 10 wherein a plurality of row arrays of transducer elements are provided and at least the row array nearest the target measures height of the implement and the other row arrays measure the horizontal position of the implement

12. Mechanical aid apparatus as claimed in Claim 10 or Claim 11 including a further row array of transducer elements beyond the target for measuring the position of striking of the target.

13. Mechanical aid apparatus as claimed in any preceding Claim including a memory for comparing a present strike at the target with a previous strike at the target.

14. Mechanical aid apparatus as claimed in any preceding Claim wherein the target moving means is a servomechanism.

15. Mechanical aid apparatus as claimed in Claim 14 wherein the servomechanism is adapted to move the target both vertically and horizontally.

16. Mechanical aid apparatus as claimed in Claim 15 wherein the servomechanism comprises: a horizontal movement portion having a fixed actuator and a horizontal control rod movable horizontally by the fixed actuator and a vertical movement portion having an actuator movable horizontally with the horizontal control rod and a vertical control rod movable vertically by the movable actuator, the target being supported on a free end of the vertical control rod for horizontal and vertical movement to meet the implement.

17. Mechanical aid apparatus as claimed in any preceding Claim, and adapted for use in assisting the striking of a golf ball with a golf club, including a strike mat having a tee slot oriented across the direction of swing of the club at the ball and a tee movable by the moving means at the tee slot.

18. Mechanical aid apparatus as claimed in Claim 17 asappendentto Claim 10 wherein the transducer elements are arrayed in the strike mat.

19. Mechanical aid apparatus as claimed in Claim 17 or Claim 18 wherein the tee has a cradle of tough plastics material provided with fingers for abutting each side of the ball, the fingers being weakened to hinge down on striking of the ball.

20. Mechanical aid apparatus as claimed in Claim 17 or Claim 18 wherein the tee is provided with vacuum means for retaining the ball on the tee until striking of the ball.

21. Mechanical aid apparatus as claimed in any preceding Claim including a printer for printing out a record of how much the target was moved to meet the implement.

22. A method of assisting the striking of a target with an implement, the method consisting in the steps of: measuring the movement of the implement towards the target; predicting the point of striking of the target; and moving the target to the predicted point of striking of the target.

?3. A method as claimed in Claim 22 wherein the measurement is effected at an early position in the implement's approach to the target to allow substantial movements of the target and at a late position to allow fine movements of the target.

24. A method as claimed in Claim 23 wherein the measurement at the early position includes a measu rement of angle of the implement's approach to the targettoallowaccountto be taken of the said angle in the prediction of the point of striking of the target.

25. A method as claimed in Claim 24 wherein the angular measurement is made during a previous strike at the target.

26. A method as claimed in any one of Claims 22 to 25 wherein the measuring means includes at least one row array of transducer elements arranged across the path of movement of the implement towards the target and the measurement is taken from a "critical" element which is the elementfurthestfrom an individual making the strike which detects passage of the implement.

27. Mechanical aid apparatus for assisting the striking ofatargetwith an implement substantially as herein before described with reference to Figures 1 to 4, Figure 5 or Figure 6 of the accompanying drawings.

28. A method of assisting the striking of a target with an implement substantially as hereinbefore described with reference to Figures 1 to 4, Figure 5 or Figure 6 of the accompanying drawings.