US 3759528 A
This invention is a machine enabling a golfer to practice golf strokes, striking a real golf ball against a net. Light reflected from the ball during flights is detected by directional detectors arranged in vertically and horizontally arranged banks, and a computer displays range achieved, lateral deviation, height deviation, lateral deviation due to spin, new distance to hole, and so on. The first bank of detectors gives information about the left-right position of the ball. The second bank of detectors gives information about the start-height of the ball and initiates a timing cycle for determining ball velocity. The third bank of detectors terminates the timing cycle. For detecting spin, the golf ball may be provided with a super-reflective semi-circular strip which is arranged to extend from top to bottom facing away from the club face. The energization of the detectors is controlled by a sensor which normally receives light radiation but is cut off from the radiation when the ball is on the tee prior to being struck. The machine also includes a club selector unit and a distance of hole selector.
Description (OCR text may contain errors)
United States Patent [1 1 Christophers et al.
[451 Sept. 18,1973
[ APPARATUS FOR SIMULATING THE PLAYING OF GOLF STROKES  Inventors: John Roland Christophers, Kings Mill, Painswick, Gloucestershire;
Derek James, Forest Green, both of England  Assignee: said Christophers, by said James  Filed: Aug. 30, 1971 21 Appl. No.: 175,957
Primary Examiner-George J. Marlo Attorney--Pierce, Scheffler 8!. Parker [5 7] ABSTRACT This invention is a machine enabling a golfer to practice golf strokes, striking a real golf ball against a net. Light reflected from the ball during flights is detected by directional detectors arranged in vertically and horizontally arranged banks, and a computer displays range achieved, lateral deviation, height deviation, lateral deviation due to spin, new distance to hole, and so on. The first bank of detectors gives information about the left-right position of the ball. The second bank of detectors gives information about the start-height of the ball and initiates a timing cycle for determining ball velocity. The third bank of detectors terminates the timing cycle. For detecting spin, the golf ball may be pro vided with a super-reflective semi-circular strip which is arranged to extend from top to bottom facing away 14 Claims, 4 Drawing Figures PATENTEU 3EH3|975 3. 759.526
sum 1 OF 4 I INVENTORS Joan Ram's Cums-nouns APPARATUS FOR SIMULATING THE PLAYING OF GOLF STROKES This invention relates to measuring apparatus, for example apparatus for simulating the playing of golf strokes and measuring the result of a stroke.
According to one aspect of the present invention, apparatus for simulating the playing of golf strokes comprises a bank of directional devices sensitive to radiation reflected from a golf ball in flight, the respective devices being sensitive to radiation received from different directions, the particular device or devices which receive radiation giving information about the position and/or status of the ball and hence about its flight path.
There may he means for illuminating an area through which the ball will pass to give the necessary intensity for illumination after reflection to energise the directional devices which may be opto-electronic devices.
One device or bank of devices may be a start device and another device or bank may be a stop device, and if each responds to passage of the ball through a different one of two parallel planes, the time interval between signals generated by the start and stop devices will be inversely related to the speed and hence the range.
Also banks of devices responsive to radiation received from different directions respectively in a horizontal and a vertical plane can give information about the direction of the flight path horizontally and vertically and whether the actual flight path is at an angle to the optimum flight path.
The apparatus may include computing equipment for giving such information as range, angle of flight, lateral deviation and so on. The ball, when placed on a tee can be arranged to cut-off light from an arm sensor, so that when the ball is driven from the tee, the sensor becomes energised and sets the computer equipment and directional devices.
The apparatus has the advantage that the ball is not captive but can be a free ball struck by a normal club against a net a few feet away after it has passed the directional device and this means the equipment can be used in any room where there is sufficient space to swing a club and this gives much more satisfaction to golfers practising.
In one form of the invention the directional devices, illuminating means and display devices for the computed information are included in a single console mounted on a low platform on which the ball is placed and on which the user can stand.
An aspect of the invention is a speed or range measuring system which can overcome the disadvantage that the time interval between the ball passing first and second parallel vertical planes is smaller for faster speeds and so cannot easily be used with conventional display equipment for displaying range which will, of course, increase with velocity.
According to this aspect of the invention a time interval is established starting and ending when an object is at two positions in a path of movement, a signal level which decays with time is produced over a time period corresponding to the time interval to establish a measured level at the end of the time period which level can be used as a measure of velocity and range. A signal level which increases linearly with time can be produced for a measured time until the increasing signal level reaches the measured level. The measured time will also be a measure of velocity and range.
The decaying signal level could be an exponential function or a series of linear function of different slopes and can start to decay at the beginning of the time interval, the value when the object is at the second position being the measured one. The linearly increasing signal can be arranged not to start until the end of the time interval. This will then give a linearly increasing time for increasing speeds or ranges of the object and this time could possibly be used as the time over which a gate is opened to feed pulses at a known frequency to a counter and display.
Another aspect of the invention is in the manner of computing a function of a flight path of an object from a signal console and according to this aspect of the invention a flight measurer comprises directional, radiation-sensitive devices responsive to radiation reflected from an object asit passes respective positions, means for providing radiation at the positions for such reflection and a computer of the flight path, velocity, and/or consequent range of the object.
It will be appreciated that the measurer does not require lamps and opto-electronic devices on opposite sides of the flight path and does not rely on the interruption of a beam of light or other radiation but by providing the illumination over a certain area and making the detectors directionally sensitive, it can use light or radiation reflected from the object as it passes and this makes for great simplicity in construction and indeed enables all the electrical equipment to be in a single console.
Preferably there are sensitive devices arranged to detect the article as it passes through different parallel planes and to detect the direction in each plane of the object from the detector. In this way vertical and horizontal deviation signals can be obtained as well as velocity signals dependent on the time to travel from one plane to the next.
It was suggested above that it is desirable to generate a decaying signal over a predetermined time interval and a further aspect of the invention is concerned with not losing the accuracy of computation even if the time interval is such that the time signal will have decayed to a low value.
According to this aspect of the invention a device responsive to signal level includes means defining a reference signal level and means responsive to the signal level being beyond the reference level to adjust the signal level automatically, for example by switching in an amplifier to modify the signal by a precisely determined factor.
Amplifiers are available with high known gain and stability which are ideal for this purpose.
The device might be a meter for measuring the signal level or a comparator for comparing it with a reference level and then the reference level would be similarly adjusted automatically when the signal level was adjusted.
The invention may be carried into practice in various ways and one embodiment will now be described by way of example with reference to the accompanying drawings, of which: 7
FIG. I is a sketch showing a golfer using the simulating equipment to practice a stroke;
FIGS. 2A and 2B is a block diagram of the electrical circuits, and
FIG. 3 is a drawing of the display unit.
The simulating apparatus comprises a platform 1 l on which the player 12 can stand to strike a golf ball 13 to hit it into a net 14, perhaps three or four feet from the edge of the platform.
A console 15 mounted on the platform has electrical components for computing the effect that the stroke would have had if played on a golf course and displays pictorially or numerically at 16 information about the range achieved, distance to left or right, height deviation from the optimum and so on. For example, if the player was simulating a drive towards a hole 560 yards distant and it was computed that the stroke he actually played achieved a range of 120 yards, but with a pull of l4 yards to the left, the computer would also compute vectorially the new distance from the lie to the hole and this could be displayed in preparation for the next stroke.
A tee for the ball 13 has a position determined by means of a bank of lamps 21 in the console and an ARM sensor 17 which will be in the shadow of the ball from the lamps when the ball is onthe tee or at the tee position. The tee can be on an area carrying a roll of artificial grass 18 which can be turned so that the ball can be placed on a surface corresponding to being on a tee or on the fairway or in the rough or possibly even in sand. The tee, ARM sensor and roll 18 are in a recess in the top of the platform about 4 inches deep and feet square so that they will be in the same horizontal plane.
The bank or lamps 21 are arranged to provide a wedge 22 of illumination through which the ball will pass if it has been struck on its way to the net 14 even if there is considerable deviation in height and direction from the optimum. As the ball passes through the wedge of illumination 22 light will be reflected on to three banks of opto-electronic devices, constituting a deviation head 24 a start/height head 25, and a stop head 26. Head 25 consists of six opto-electronic devices, head 26 consists of six devices and the deviation head 24 21 devices. These are collimated or masked so that they respond only to light arriving from a restricted area. The heads 25 and 26 are positioned in the console and the head 24 is in the recess in the platform in front of the tee.
Each head responds only to light reflected from one vertical plane and the three vertical planes are spaced from the driving spot in the order 24, 25, 26. In each head each sensitive device is controlled to receive light over an arc and the arcs for neighbouring sensitive devices just adjoin one another or slightly overlap. This means that the position of the ball as it passes the vertical plane concerned can be partly determined in accordance with whichsensitive device (or which two adjacent devices) receive light as it passes.
It will be seen that the deviation head 24 has devices spaced apart horizontally whereas the start/height head has devices spaced apart vertically, The first head 24 gives information about the position of the ball horizontally, and the second 25 about the position vertically. The arm sensor 17 energises the electrical equipment in preparation for passage of the ball through the vertical and horizontal planes as soon as the ball is struck and leaves the tee and the sensor 17 is energised from the lamps 21. The stop head, 26, is merely for giving a stop signal when the ball passes that vertical plane. The deviation 24 and start/height 25 heads have to give further information as will be described in more detail from references made to FIG. 2.
Referring now to FIG. 2, the three heads consisting of opto-electronic devices are indicated at 24, 25, 26 and the different displays-namely the Left/Right and width displays, a high-low deviation display and a distance or range display are shown at 31, 33, 32 and 34 respectively.
Prior to playing his stroke, the player sets manually a Club selector unit 35 and a Distance of Hole" selector 28 controlling an arithemetic unit 29, in accordance with the particular club he is going to use and the distance of tee to hole. The Club selector" unit is designed to supply a reference voltage dependent upon the theoretical height of the ball if correctly struck with that club as it passes the start/height vertical plane corresponding to the head 25. This information has already been calculated for various clubs so that the unit merely acts as a voltage selector and the voltage se lected is compared in a comparator 36 with a signal derived from the start/height head 25 responsive to the actual height of the ball as it passes that vertical plane. The output from the comparator 36 controls the HIGH-LOW display 32 and controls a function generator 37 which is arranged when it receives an initiation signal to generate a decaying variable linear function. The generator 37 can generate a number of different linear functions in accordance with different fixed component values which can be set in and the particular component set in will depend upon the output from the comparator 36. Thus if the height actually achieved corresponds with the theoretically correct height of the ball. passing the start/height electrical plane, a particular linear function will be generated whereas if there is an error whether too high or too low a different linear function will be generated and the particular function will depend upon the amount of vertical deviation and its sense whether too high or too low.
The start/height head 25 is also arranged when the ball passes that vertical plane to' initiate a programmer 38 through a l millisecond-delay circuit, for ensuring that the function generator has been correctly set. The programmer 38 then sends an initiating signal to the generator 37.
When the ball passes the vertical plane for the stop bank 26 a signal is generated which stops the function generator 37 via the programmer 38 and the amplitude of the decaying linear function at that instant remains stored in a level store 39, and this voltage in the level store 39 is fed to one input of a comparator 43. The programmer also initiates the action of a ramp generator 42 and simultaneously opens a gate 41. The generator 42 starts to generate a linearly rising voltage signal which is fed to the other input of the comparator 43. The ramp generator 42 generates its ramp until the ramp voltage corresponds with the voltage held in the level store and then the comparator 43 is arranged to close the pulse gate 41. Appropriate delay circuits are included to ensure that the ramp generated at 42 does not start until the stop signal has been generated at 26 and the level store 39 is holding a final voltage from the function generator. This is a feature of a range expander delay unit 40 and will not be described in detail.
The gate 41, ramp generator 42, and comparator 43 are included in a range integrator 50 controlled by a range control 54.
The gate 41, while it is open, passes output signals from a crystal oscillator 44 to a counter 45 arranged to drive the range display 34 through a conventional binary coded decimal unit. It will be appreciated that the gate is open for a time corresponding to the time for the ball to travel through the vertical plane corresponding to the start head 25 to the vertical plane corresponding to the stop head 26 and this time will be a measure of the velocity of the ball and will be directly indicated by a number of pulses that have passed the gate 41. It only requires conventional electrical techniques to translate this velocity into yards of range for direct display at 34 in dependence on the particular club used which has been set in at 35. A further display 46..of the distance from the lie to the hole can be driven from the arithmetic unit 29.
The deviation head 24 determines whether the ball has been struck straight or has been sliced or pulled and it is a simple matter to control display 31 to indicate slices or pulls. The output from the head 24 is also supplied to control a divider 47 which receives the pulses from crystal oscillator 44 and divides them by a factor dependent on the degree of deviation as determined by the opto-electronic devices in the head 24. These pulses are counted in a counter 48 for direct display on the Left/Right width display 33 in terms of yards of deviation to left or right from a direct line from the tee to the hole. It will be clear that this measurement can be obtained by simple division at 47 and by use of an input from the range measuring system because the greater the degree of deviation horizontally and the greater the range of stroke the further will the ball deviate from the straight line.
A feature of the invention is the method of obtaining accurate computation even if the function generated at 37 has decayed to a small value by the time the stop signal is received from the stop head 26. Thus the output from the function generator 37 is supplied as one input to a comparator 51 whose other input receives a reference voltage from 52 corresponding to a voltage level of the function below which it may be difficult to get accurate comparison and computation. Once the function has decayed to this low voltage the comparator 51 produces an output to operate an electronic switch shown diagrammatically at 53 which is arranged to connect the output from the function generator 37 to the comparator 43 through an amplifier in the control 54 instead of directly and to connect the output from the ramp generator 42 to the comparator 43 through an amplifier 55 in the control 54 instead of directly.
The range control 54 and amplifier 55 given an accurate stable known gain of perhaps :1 so that the signals to be compared at 43 are still accurately related to each other but are of a magnitude enabling a more accurate comparison to be made.
It will be appreciated that the machine or apparatus can be used anywhere where there is room to swing a club and a supply of electricity and that the player strikes a real ball with a real club, which is a very desirable feature in a simulating apparatus but which nevertheless enables accurate computation to be achieved.
It is also possible to detect the rate and sense of spin on the ball by a detector 58 which responds to light reflected from the golf ball as it spins.
The ball carries a "super-reflective semi-circular strip which is arranged to extend from top to bottom facing away from the club-face, when the ball is on the tee and pulses are reflected from it to the sensor as the ball spins about an axis with a vertical component. The spindetector 58 is switched on by the arm sensor 17 and switched off by the first pulse reflected from the ball as it spins. The sensor is adjusted to be only responsive to a pulse received from the super-reflective strip. The time between striking the ball. and reception of the first pulse is dependent on the rate of spin about a vertical axis, being shorter for higher spin rates.
Pulses from the oscillator 44 are counted drawing the measured period, the number counted being smaller for higher spin rates.
Counts so high as to represent a spin of less than 60 revolutions per second are considered to produce no appreciable spin, and the system does not respond to such high counts.
In order to achieve a signal which increases with spin rate for display in conjunction with the Left/Right display due to pull or slice, the spin unit 60 and divider 47 are coupled with the integrate 50 and ramp generator 42 arrangement in the same manner as described for measuring range.
The spin system is based on the assumption that we are only interested in spin afiecti'ng ball movement in the horizontal plane. Spin in the vertical plane is already taken care of by the error" in the angle that the ball takes off at in the vertical plane when the ball is incorrectly hit. This simple arrangement produces a fairly accurate answer.
The display is a combination of accumulated deviation due to direction of striking and accumulated deviation due to spin.
A system-functioning indicator 61 is shown in FIG. 2 and 3. It has three lamps arranged to be lit when signals are received respectively from the arm sensor 17, and the start and stop heads 25 and 26, and when all three are alight, the user knows that operation is satisfactory.
lt will be clear that the apparatus lends itself to further development. For example, the information derived in the computer can be displayed remotely and can indeed be used in conjunction with visual presentation so that the player can see projected on a screen a picture of the hole both as seen from the tee and from lies in a number of different directions, all of which could have been pre-recorded on an actual golf course and the selected one of which could be projected for the next stroke in accordance with the lie. It is aso a simple matter to add into the computer a factor representing a desired wind speed and direction and of course if the width of the fairway is fed into the computer it can also give an indication whether the ball has landed on the fairway or in the rough so that the lie selected at 18 for the next shot can be correctly arranged. Bunkers can be set in and the computer will determine whether the ball has ended in a bunker. The information can also be recorded for subsequent analysis and game play.
What we claim as our inventionand desire to secure by Letters Patent is:
1. Apparatus for simulating the playing of golf strokes comprising a first bank of differently directed directional devices sensitive to radiation reflected from a golf ball in flight, and first electrical connections from the first bank for giving a first electrical signal representing a first characteristic of the: trajectory of the golf ball, a second bank of differently directed directional devices snesitive to radiation reflected from a golf ball in flight, and second electrical connection from the second bank for giving a second electrical signal representing a second characterisitc of the trajectory of the golf ball, directional devices sensitive to radiation reflected from a golf ball in flight spaced apart in the direction of flight, for deriving start and stop signals, and means for determining from the start and stop signals a range signal related to the velocity of the ball, and a computer responsive to the first and second electrical signals and the range signal for computing what would be the termination of the flight of the ball.
2. Apparatus as claimed in claim 1 including means directing radiation at the area through which the ball will pass after being struck.
3. Apparatus as claimed in claim 1 including start and stop devices respectively sensitive to radiation received from two different vertical planes spaced apart along the flight path.
4. Apparatus as claimed in claim 3 including means arranged to measure the time interval between reception of radiation by the respective start and stop devices.
5. Apparatus as claimed in claim 3 including a generator of a decaying function commencing when the start device receives radiation, and ending when the stop device receives radiation, with the function at a measured level.
.6. Apparatus as claimed in claim 5 including a generator of a ramp function which increases linearly with time, and means responsive to increase of the function to a value corresponding to the said measured level.
7. Apparatus as claimed in claim 6 including a pulse generator and means responsive to the number of pulses generated over the time necessary for the ramp function to reach the said corresponding value for giving an indication of ball velocity or range.
8. Apparatus as claimed in claim 7 including a divider arranged to use a proportion of the said number of pulses to give an indication of deviation to left or right of a desired flight path, the proportion being dependent on which of the bank of horizontally spaced devices receives radiation from the ball as it passes the plane of that bank.
9. Apparatus as claimed in claim 5 including means defining a reference signal level and means responsive to the measured level being belowthe reference signal level to adjust the signal level automatically.
10. Apparatus as claimed in claim 9 in which the automatic adjustment is effected by switching in an amplifier operating with a precisely determined gain.
11. Apparatus as claimed in claim 1 including a sensor which normally receives radiation but is cut off from the radiation when the ball is on a tee prior to being struck, which sensor operates to render devices operative when the ball leaves the tee.
12. Apparatus as claimed in claim 1 including a platform for supporting the golfer and the golf ball prior to its being struck and a net for stopping the golf ball after it has been struck, the devices being sensitive to radiation received from different directions in vertical planes between the striking place and the net.
13. Apparatus as claimed in claim 1 including a sensor responsive to pulses of radiation received from the ball in flight as'it spins about an axis with a vertical component, and means for providing from the sensor a signal related to the lateral deviation of the flight path due to the spin.
14. Apparatus as claimed in claim 13 including means for superimposing the deviation due to spin on the flight deviationdue to the direction in which the ball is struck being to right or left of the desired direction.
Patent 3, 759,528 Dated September 18 1973 John Roland Christophers et a1. Inventor(s) a I It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Claim 1, line" 1 (column 7) "'snesitive" should read sensitive line 2 (same column) "connection" should read connections Signed and sealed this 19th day of February 1974.
(SEAL) =1 Attest:
EDWARD M.PLET CHER,JR. A HALL DANN Attesting Offi Commissioner of Patents FORM PO-1050UO'69) uscoMM-oc: 60376-P69 Y US. GOVERNMENT PRINTING OFFICE "I! O3S33l,