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WO1998018010A1 - Appareil de mesure des parametres relatifs a la trajectoire et/ou au mouvement d'un mobile - Google Patents

Appareil de mesure des parametres relatifs a la trajectoire et/ou au mouvement d'un mobile Download PDF

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Publication number
WO1998018010A1
WO1998018010A1 PCT/GB1997/002873 GB9702873W WO9818010A1 WO 1998018010 A1 WO1998018010 A1 WO 1998018010A1 GB 9702873 W GB9702873 W GB 9702873W WO 9818010 A1 WO9818010 A1 WO 9818010A1
Authority
WO
WIPO (PCT)
Prior art keywords
light
sensing means
clubhead
article
detection plane
Prior art date
Application number
PCT/GB1997/002873
Other languages
English (en)
Inventor
Norman Matheson Lindsay
Original Assignee
Norman Matheson Lindsay
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from GBGB9621828.4A external-priority patent/GB9621828D0/en
Application filed by Norman Matheson Lindsay filed Critical Norman Matheson Lindsay
Priority to GB9908258A priority Critical patent/GB2334781B/en
Priority to JP10519097A priority patent/JP2001502428A/ja
Publication of WO1998018010A1 publication Critical patent/WO1998018010A1/fr
Priority to US10/090,363 priority patent/US6887162B2/en
Priority to US11/046,914 priority patent/US20050130755A1/en

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
    • G01P3/00—Measuring linear or angular speed; Measuring differences of linear or angular speeds
    • G01P3/64—Devices characterised by the determination of the time taken to traverse a fixed distance
    • G01P3/68—Devices characterised by the determination of the time taken to traverse a fixed distance using optical means, i.e. using infrared, visible, or ultraviolet light

Definitions

  • This invention relates to apparatus for measuring parameters relating to the trajectory and/or motion of a moving article and in particular, apparatus for measuring and recording the pre-impact and post-impact position and/or motion of a golf clubhead and golf ball during the execution of a golf shot
  • a typical conventional golf swing analyser a plurality of discrete light sensors are arranged in line at regular known intervals with two or more such arrays built into a playing mat and extending transversely to the intended direction of clubhead travel prior to ball impact
  • the light sensors are normally illuminated from a single source at ceiling height so that the effective light beams received by each sensor in an array are approximately parallel and vertical
  • the light sensors detect the shadow of a clubhead as it travels at speed towards a golf ball
  • the present invention aims to provide more extensive and more precise data using only a relatively small number of sensor signals
  • apparatus for measuring parameters relating to the trajectory and/or motion of a moving article
  • the apparatus comprising one or more light sources for providing light emitted from or reflected by the moving article and one or more light sensing means each arranged to provide a signal when the respective sensing means is illuminated by said light, wherein at least one of the light sensing means is arranged to detect when the moving article intercepts a given detection plane wherever the article intercepts the detection plane, the arrangement being such that the position and orientation of the detection plane relative to a reference point is known or can be deduced from the signal provided by the said at least one sensing means
  • the apparatus is provided in combination with one or more articles the movement of which is to be sensed, the or each of the articles being provided with a reflective portion and/or light emitting means
  • the article may comprise a golf club and according to a further aspect of the invention there is provided a golf club for use with the apparatus, the golf club being provided with at least one diffusely reflective region surrounded by a relatively non-reflective region and/or with at least one light emitting means together with a power source therefor
  • the position of a golf ball is fixed (motionless) relative to the apparatus and normally only measurements of the golf clubhead are performed
  • the post-impact measurement phase only measurements of the golf ball motion are normally required but measurements of the post-impact motion of the clubhead can also be obtained to yield additional information on the impact event
  • Apparatus according to the invention may be used to provide fast quantitative measurements of various parameters of a golf shot and is of benefit to golfers in providing feedback relating to important aspects of their shot making skills
  • the apparatus is also useful for purposes of custom club fitting, where measurable parameters of a golfer's swing are used in a decision process to select the properties of various components that comprise a golf club
  • the invention may also be used in golf simulation equipment where it is required to compute the hypothetical free flight of a golf ball off a golf shot in confined, flight restricting environments
  • the purpose of performing measurements on both the clubhead and the golf ball is to obtain data that could not easily be obtained by measuring only the clubhead or only the golf ball
  • the ball When the ball is struck, it initially remains in contact with the clubface and travels a distance of a few millimetres before parting from the club Thereafter, the ball travels through the air in a direction that is primarily determined by the pointing direction of the clubface at initial impact and by the direction of motion of the clubhead at initial impact As it travels through the air, the ball is subject to gravity and to various aerodynamic forces but in the first few metres of flight the combination of all these forces has very little effect on the direction of travel, so the initial flight path can be considered to be straight to within a very small fraction of a degree for all normal full swing golf shots
  • the motion of the clubhead is not rectilinear Prior to impact the clubhead moves in a curvilinear arc and is subject to significant rotation about the shaft axis
  • the curvature and plane of the clubhead arc differ from player to player as does the rate of clubhead rotation
  • This curvature of the clubhead motion leads to significant measurement errors in known apparatus where typically swingpath angles are measured at only two points along a substantial portion of a clubhead path prior to impact
  • apparatus is preferably capable of predicting the motion of the clubhead very near the point of impact and be capable of resolving small angular differences (e g ⁇ 0 5° or better) between the immediate pre-impact motion of a clubhead and the ensuing flight of a ball struck by said clubhead
  • small angular differences e g ⁇ 0 5° or better
  • Many known apparatus in common use provide only relatively coarse resolution (typically l 0° for swingpath angle) and are capable of only two dimensional measurements of horizontal components of motion and orientation
  • important parameters such as attack angle, dynamic loft and dynamic lie are absent
  • Preferred embodiments of the present invention provide equipment which measures clubhead and ball behaviour in the impact region using arrays of electro-optical sensors in conjunction with light aperturing and/or light focusing devices in configurations that provide high quality measurements of all parameters relating to the dynamics of a clubhead-o ⁇ -ball impact and more extensive and more precise data is provided using only a relatively small number of sensors
  • apparatus according to the invention may be used with any standard make of golf club or golf ball and the playing surface or tee-off arrangement can be of unrestricted form as these do not need to form part of the measurement equipment
  • one or more parts of a clubhead are selectively illuminated as the clubhead travels through a region just prior to impact with a golf ball Additionally, one side of the said golf ball is selectively illuminated during part of its initial flight trajectory after impact
  • the above selectively illuminated parts of a clubhead cr ball are hereinafter referred to as highlights
  • Light emitted from each highlight is detected by a plurality of electro-optical sensor devices arranged in sensor arrays with at least one array configured to detect clubhead highlights and a separate array configured to detect the ball
  • the combination of a sensor device with an aperture and/or focusing lens is arranged to provide a wide angle of view in one plane with a narrow angle of view in the orthogonal plane
  • the field of view as a 'detection plane'
  • the wide angle of view of the detection plane preferably extends over at least 5 degrees and in some cases, may extend over at least 120 degrees
  • the narrow angle of view in the orthogonal direction, which determines the thickness of the detection plane preferably extends over 1 degree or less or more preferably over 0 25 degree or less In a typical case, with a divergence of 0 25 degrees and a highlight at a distance of 36 cm from the light sensor the thickness of the detection plane at the point the highlight passes through it will thus be less than 2 mm
  • the detection planes are preferably arranged to traverse the path of a clubhead or ball at various positions along the path and at various angles thereto As a highlight travels into the field of view of a sensor, data capture circuits record the time and amplitude response of the sensor to the received incident light These data are used to compute the speed position and direction of the highlights and thus the clubhead and ball motion
  • the said sensor devices comprise discrete sensors (i e having one signal responsive to light incident on one small photo-sensitive area) and the said apertures and/or lenses comprise slit apertures and/or cylindrical lenses
  • the sensor devices are elongate and may comprise a linear pixel array (e g a CCD array) or an electro-optical one dimensional position sensitive detector (PSD), whereas the apertures are 'pin-hole types (i e small, circular apertures or the like) and the lenses are spherical, focusing to a point
  • the linear pixel array the field of view is composed of a set of overlapping narrow conical beams spread across the detection plane and the linear pixel array is used as a form of position sensitive detector
  • Both the sensing device and the coacting combination of aperture and/or lens may also be elongate When two such elements are combined (e g a slit aperture coacting with a linear CCD array), a set of detection planes are provided corresponding to each of the pixels in the CCD array When the slit aperture and the CCD array are parallel the above set of detection planes are co-planar and overlapping, but offset slightly from each other When the slit aperture and coacting CCD array are not parallel, then the set of detection planes do not overlap
  • the highlights are provided by direct light emission from specially mounted light emitting devices on a clubhead (primary highlights) or by reflection from diffusely reflecting zones (secondary highlights) provided on the clubhead or ball using fixed position primary light emitting arrays to illuminate the reflective zones
  • the highlight from a golf ball is preferably of the latter (secondary) type, and the reflecting zone comprises the hemispherical surface on an illuminated side of said ball
  • the light emission from a highlight may be continuous or pulsed
  • low duty cycle pulsed emissions with a repetition frequency in the range 10kHz to 100kHz are used with measurements coinciding with each pulse This corresponds to providing measurements of a clubhead and ball positions at intervals of a few millimetres to a fraction of a millimetre (In a 'full swing' golf shot the clubhead speed at impact is typically in the range 25m/s to 55m/s, and ball launch speeds are typically 30% to 60% greater)
  • highlights for a clubhead are provided as light emitting devices (LED's) which are mounted at known positions on the clubhead (typically near the heel and near the toe)
  • the LED's are mounted on a small circuit substrate that is detachable from the clubhead and this substrate contains a suitable compact battery power source and means for controlling light emission and power drain
  • a suitable controlling means comprises a light detector and timing circuitry that are also mounted on the circuit substrate The detector converts incident light from an external controlling light source into a signal that enables an on-board timer and this, in turn, powers the LED's for a predetermined period and also allows time multiplexing of highlights when two or more are provided on a clubhead In this manner the average power consumed by the LED's can be significantly limited by being switched on for only a few milliseconds during each swing
  • the LED's and light detector operate in the near infra red (IR) spectrum but visible light or other light wavelengths may be used Using IR wavelengths allows the clubhead mounted assembly
  • highlights for a clubhead are provided as diffusely reflective zones on one or more known positions on the clubface surface
  • the highlights reflect light uniformly across the area of the reflective zone
  • the reflective zones may be circular, but advantageously the zones are specially shaped to enhance the time varying amplitude response of the received sensor signals and to provide features that indicate the orientation and/or position of the highlight relative to a detection plane
  • One or more primary light sources are preferably provided adjacent to the clubhead-on-ball impact zone and positioned to efficiently illuminate the diffusely reflective zones as the clubhead approaches the ball resting position, but also positioned a safe distance e g at least 20 cm away from possible contact by a clubhead during a normal golf shot
  • An associated sensor array is configured to accept light from such a highlight and means are preferably provided to substantially exclude from the collective field of view of the sensor array, reflected light from other parts of the clubhead and also from background reflections
  • the clubhead surface closely adjacent to a highlight is provided with a non-reflective coating
  • Other parts of the clubhead surface can advantageously comprise polished or mirror-like reflecting surfaces, providing that such surfaces reflect the primary light source in directions other than into the collective field of view of the sensor array, taking account of the directional characteristics of the primary light source
  • Figure 1 is a schematic diagram in plan view of a clubhead a golf ball and apparatus according to one embodiment of the invention at an instant of a swing just prior to impact,
  • Figure 2 shows a rear end view of the arrangement in Figure 1
  • Figure 3 shows a side view of the arrangement in Figure 1 at an instant of a swing following impact
  • Figures 4A and 4B show details and views of two types of clubhead adapted for use with the invention
  • Figure 5 is a schematic diagram of an arrangement of detection planes for measuring the initial launch trajectory of a golf ball
  • Figure 6 shows time dependent waveforms of typical signals that are generated by the arrangement of Figure 5
  • Figure 7 shows a scale drawing in plan view of preferred additional mechanical details of the arrangement of Figure 1 ,
  • Figure 8 shows a front view of the arrangement of Figure 7
  • Figure 9 is a schematic diagram of an arrangement of discrete sensors and slit aperture to provide two coplanar detection planes, according to another embodiment of the invention, Figure 10 shows time dependent waveforms typical of signals that are generated in the arrangement of Figure 9
  • Figure 11 is a diagrammatic plan view illustrating the combination of a PSD device and a slit aperture used in further embodiment of the invention.
  • Figure 12 is a diagrammatic side view of the arrangement shown in Figure 11
  • X Y and Z are shown in the drawings
  • the Z axis is vertical and points upwards
  • the Y axis is horizontal and points along the general azimuth direction of ball travel
  • the X axis is orthogonal to Y and Z and points in the general 'heel-to-toe' direction of a clubhead at ball address
  • a golf ball 1 rests on a rubber tee 2 (shown by dotted circle)
  • the tee 2 is semi-permanently fixed to a playing surface or play-off mat 3
  • Other ball placement arrangements may be adopted, for example the ball can be placed directly on a mat or on turf provided that the placement spot is nominally on a known vertical axis in relation to the apparatus
  • An IR transmitting and receiving (TX/RX) assembly 4 is provided in a known position and orientation relative to the resting position of the golf ball 1
  • a signal and power cable 5 connects the TX/RX assembly 4 to signal control, data capture and display unit 6 which can be implemented either as a dedicated control and display module or (via suitable interfacing) as a general purpose stand-alone computer such as a 'PC system
  • IR emitters 25 on the TX RX assembly emit a beam or beams of IR light towards the toe end of a clubhead 7
  • the IR emission is preferably pulse modulated with a repetition frequency of the order of 50kHz or higher so that ac coupled signal amplification can be applied thus rejecting low frequency background light interference
  • Some of the pulse modulated light is reflected back towards the TX/RX assembly where it passes through a series of slit apertures 23 60 61 (see Fig 3) provided on the front face 8 of the TX RX assembly
  • light reflects off a specially designed diffusely reflecting zone provided on the toe end 9 of the clubhead Light from this diffusely reflecting zone is intended to be the dominant component of back reflected light from the clubhead This dominant reflecting zone is referred to herein as a highlight
  • a signal proportional to the instantaneous quantity of light incident on the sensor is generated and stored as data Analysis of the data allows accurate estimation of the instant in time when the centre of the highlight was positioned along the major plane of the field of view of a given sensor For convenience, such a plane is referred to hereinafter as a detection plane Knowing the relative positions and angles of all the detection planes, parameters such as the clubhead speed and swingpath angle can be found from analysis of the highlight time and position data
  • a second IR TX/RX assembly comprising a TX array 14 and RX array 15 with corresponding signal and power cables 16 17 for connection to the data capture and display unit 6
  • the TX and RX arrays are shown for clarity as separate units, but in practice these would advantageously be combined into a single assembly
  • the TX array comprises a number of small area IR emitters 18 mounted at approximately equal spacing along a line parallel to the X axis
  • the direction of peak emission for all the IR emitters 18 is typically vertically upward and the individual beams merge so that at some distance away from the emitters, the beams merge so as to effectively provide a single wedge-shaped beam extending some way on either side of the general ball flight path and with the wedge angle large enough to include the volume occupied by detection planes 19, 20 (see Figure 3) at ball trajectory height
  • the beams axes may be tilted in the Y-Z plane away from the ball rest position 1 This alternative arrangement improves the spatial separation of a launched golf ball 1 * (see
  • the RX array 15 comprises a top part which contains a plurality of narrow, elongate apertures 10, 11 12 and coacting with these apertures a plurality of sensor devices with associated circuitry arranged below the apertures and inside the RX array 15 so as to form a series of detection planes for measuring the direction and velocity of a launched golf ball 1 *
  • the sensor devices are photo-electric sensors, such as light-detecting diodes
  • Three apertures 12 are co-linear and these are each used in conjunction with a respective pair of sensor devices to form two detection planes that are transverse to the Y direction (i e transverse to the general direction of ball flight)
  • the two detection planes each comprise three smaller planes associated with the three co-linear apertures 12, and these smaller planes are nominally co-planar and merge to form the overall detection plane
  • the purpose of using three smaller planes is to increase the detection zone to ensure that all ball trajectories pass through part of the overall detection plane This is particularly required for low trajectory shots where a single central aperture would not cover off-line shots
  • the two main detection planes are shown (illustratively) by dotted lines 19 20 in Figure 3
  • the detection plane denoted by dotted line 19 is vertical whereas that denoted by dotted line 20 is at an angle to the vertical
  • both planes can be at equal or different angles to the vertical and tilted in opposite directions in the Y- Z plane
  • FIG. 5 A schematic view of an arrangement for analysing ball flight using such detection planes is shown in Figure 5
  • Two detection planes denoted by dotted lines 19 and 20 are normal to the page of the diagram
  • a launched golf ball 1 * passes through the planar light beam generated by the TX assembly 14, it reflects light back throughout a wide angle Some of this reflected light is incident on the RX array and passes through an aperture 12 to form a narrow slit of light
  • Light sensors 50 51 are positioned below the aperture 12 and the fields of view that pass through the aperture from the two sensors form the detection planes centred along the dotted lines 19, 20 respectively
  • After launch the golf ball 1 * flies above and over the RX array 15 and first passes through the detection plane denoted by dotted line 19 and then through the detection plane denoted by dotted line 20
  • Waveform 52 exhibits a peak 53 corresponding to the instant in time when the ball 1 * is oositioned centrally in the detection plane denoted by dotted line 19
  • waveform 54 exhibits a peak at 55 when the ball is central in the detection plane denoted by dotted line 20
  • the waveform maxima are nearly flat and thus their exact time of occurrence are difficult to determine accurately by direct timing
  • the timing of the peaks is measured by capturing data from the rising and falling edges of the pulse waveform (on either side of a peak) and assuming that the pulse shape is symmetrical about its peak
  • the maxima can be found to the necessary accuracy using only sparse data such as the timings of transitions above and below a fixed threshold on the rising and falling edges
  • the pulse width durations pw1 and pw2 correspond to the passage of the ball 1 * through detection planes 19 and 20 respectively
  • pw2 is greater than pw1 because the ball takes longer to pass through detection plane 20 as this plane is more oblique (than detection plane 19) to the ball trajectory
  • the pulse widths are proportional to the diameter of the ball 1 * and inversely proportional to the ball speed and to the sine of the angle subtended between the ball flight path and the detection plane
  • the time separation (t2 - t1 ) between the pulse waveform peaks is also inversely proportional to ball speed and increases with the launch angle of the ball
  • the ball speed and launch angle can be calculated by solving three simultaneous equations equating ball speed, ball diameter and launch angle with the measured values of pw1 , pw2 and (t2 - 11 )
  • a simpler calculation is obtained if the time of initial launch of the ball is known
  • the initial launch time t0' is (to within a very small and determin
  • ⁇ is the ball launch elevation angle
  • ⁇ is the angle of detection plane 20 relative to the horizontal
  • K is equal to (t2 - t1 )/(t1 - tO)
  • Ys is the distance between the ball resting spot and the vertical detection plane 19
  • the slit apertures 10 and 11 are arranged at oblique angles relative to the series of three collinear apertures 12 Coacting with each of the apertures 10 11 , there are provided one or more light sensors positioned vertically below the corresponding aperture so as to form one vertical detection plane for each aperture 10, 11
  • two nominally vertical detection planes are provided at oblique angles relative to the vertical X-Z plane
  • dotted lines 19 21 and 22 denote the positions of vertical detection planes corresponding to apertures 12, 10 and 11 respectively It can be seen that this group of detection planes form a triangle with the planes also extending beyond the sides of the triangle
  • the azimuth direction of ball flight can be calculated in a similar manner to the calculation shown above for elevation angle
  • Each detection plane is coplanar with a slit aperture and at least one coacting light sensor Where two or more light sensors are used to form a detection plane, the signals from each sensor are combined to make one composite signal Two or more detection planes may also be formed using a single slit aperture (as exemplified in Figure 5)
  • the side of the TX/RX assembly 4 shows a series of vertical slit shaped apertures 23 on the front face 8 of the TX/RX assembly
  • These apertures allow light reflected off the toe of a clubhead (during a pre- impact phase) to be incident on corresponding light sensors placed at appropriate positions at some distance behind the front face 8
  • the primary light source that provides the incident light on the clubhead comprises high intensity IR emitters 25 and these may be mounted on the front face 8 so that only back reflected light from the emitters is incident on light sensors behind the front face
  • the emitted IR light may be continuous or pulsed
  • two modes of light emission are provided in a standby mode, very short duration pulses are emitted from at least one emitter and operating in low duty cycle so as to conserve standby power
  • a wide angle photodiode 26 with appropriate fast response detection circuitry monitors the level of any light reflected back from an object in the field of view If this level is above a threshold indicating the presence of reflection from a clubhead or equally reflective object the system switches into data capture mode with longer pulse duration and/or higher duty cycle
  • the data capture mode is maintained for a duration greater than the maximum dwell time of a clubhead in the measurement zone taking account of the slowest expected swing speeds Alternatively, the data capture mode may be stopped by an interrupt that is generated from an acoustic sensor or other means when the clubhead impacts the ball
  • the receiver part of the TX/RX assembly 4 operates in a similar manner to the RX array 15 described above, except that the ball is replaced by a circular reflector zone or highlight 27 attached to the toe 9 of a clubhead 7 and this moves in a direction approximately parallel to the row of apertures 23
  • the highlight 27 passes through a series of detection planes formed by the apertures 23 and associated light sensors, and this enables the clubhead speed, swingpath angle and off-centeredness (impact point) to be determined
  • Two additional slit apertures 60, 61 are orientated at an angle to the vertical and in conjunction with light sensors placed some distance behind, provide two detection planes (denoted by dotted lines 62 63) that are normal to the Y-Z plane but tilted at a known angle (or angles) to the vertical
  • the detection planes 62 63 enable measurements of clubhead elevation path (attack angle) and height at impact
  • FIG. 7 shows the relationship between a golf ball 1 and apparatus comprising a TX/RX assembly 4 and a cover 70
  • Figure 7 also shows the nominal positions of four vertical detection planes that are necessary to implement measurements of clubhead speed, swingpath and impact offset These detection planes are denoted by dotted lines 64, 65, 66 67
  • the overall height 'h' is preferred to be not greater than the height of the centre of the golf ball 1 on its tee 2 (i e 30mm or less)
  • the separation 'd' between the tee spot and the top edge of the apparatus is typically 24cm or greater, giving a generous margin of clearance so that the apparatus is well out of range of wayward clubhead swingpaths
  • the size of the slit apertures used will depend on the required geometry of the system but they will typically have a length in the range 5 - 30 mm and a width of 1 mm or less and preferably 0 25 mm or less
  • the apertures 23 are preferably formed at or near the same distance d from the tee spot, and the associated light sensors are typically a further 0 5d beyond the apertures so that the overall distance from tee spot to light sensing devices is typically 36cm
  • the distance between the sensors and apertures would be typically 25mm with the distance between the ball and apertures in a range from a few centimetres to 50cm or more This greater ratio of distances (compared with the clubhead measuring system TX/RX 4) is allowed because the required accuracy of ball position measurement is proportionally less
  • the front cover 71 must be sufficiently transparent to IR light to allow proper operation of the TX/RX assembly 4
  • the whole cover assembly 70 is fabricated from a high impact and scratch resistant plastic containing a dye that forms an IR transTnissive filter while being virtually opaque to visible light
  • the cover can be provided with a cladding that acts both as an impact cushion and a cosmetic covering In this case the cladding must be selectively removed where necessary to permit correct reception and transmission of IR light to and from the TX/RX assembly 4
  • the TX array 14 and RX array 15 are protected from damage by ball impact using a form of impact deflector suitably positioned to cushion and/or deflect low trajectory balls that could result from 'topped' shots
  • the height (i e the thickness) of the tee-off mat 3 is typically 30mm or greater the overall height of the TX array is preferably made equal or less than this height so that a 'topped' golf ball flies clear of the TX array
  • the arrays 14, 15 are preferably constructed as an integral unit and mechanically linked to the TX/RX assembly 4 so as to maintain correct alignment
  • TX/RX assemblies 4 and 14, 15 may be positioned at the edges of a tee-off mat and that with the arrangement described, no emitters or sensors are required in the mat
  • Figures 4A and 4B show toe-side views of an iron' type clubhead 28 and a 'wood' type clubhead 29 modified for use with the invention
  • Diffusely reflecting highlights 30 31 are positioned on or near the extreme toe parts of the clubheads Matt black surface areas 32, 33 surround these reflecting highlights and cover the parts of the toe regions that could direct strong reflections from the IR emitters 25 back towards the TX/RX assembly 4
  • the matt black surface areas 32, 33 are designed to have as low a reflectivity to incident IR light as is practical, and any surface form that achieves this aim may be used
  • the reflecting highlights 30 31 are typically brilliant white surfaces or they may be highly reflecting polished surfaces with an overlay of translucent light diffusing material The reflecting highlights should ideally emulate the characteristics of a perfectly diffusing reflector with a lambertian pattern of reflected light intensity
  • the clubhead 29 is typical of the clubhead used in Figure 1
  • the highlight 31 is in the form of a circular area with two lateral triangular segments removed It will be appreciated that the quantity of light reflected from this form of highlight increases in approximately a linear manner as the centre of the highlight 31 passes into a detection plane, and then decreases in a similar manner as it passes beyond the plane so as to provide a signal with more clearly defined maxima compared to that shown in Figure 6
  • the clubhead rotates about the X axis (for small angular rotations, typical of clubhead behaviour) the same general shape and peak amplitude of response is maintained
  • the purpose of removing the triangular segments from the circle is to shape the obtained signal response and increase the detectability of the centre of the highlight
  • the modification to a standard clubhead comprising the reflecting and non-reflecting portions can be provided as a self adhesive printed label, but other forms of modification can be provided
  • lightweight rubber or plastic moulded attachments can be provided, and this also allows modification of the surface profile to optimise the light source characteristic
  • a second highlight on a clubhead it is preferable to position this remote from the toe highlight, for example on the back of a clubhead and near the heel or on the hosel This allows measurement of clubface angle and rotation providing the positions of the highlight centres are accurately known in relation to the clubface
  • the outputs from discrete sensors 100, 101 are amplified and give rise to signals V3 and V4 respectively
  • the two sensors are positioned in vertical relationship and receive light through an aperture stop 102 that provides a vertical slit aperture
  • the resulting combined angle of view contains two detection planes that are coplanar, vertical and overlap in the region 103 (shown shaded) It will also be noted that the detection plane defined by sensor 100 terminates just above the surface of the tee-off mat 3.
  • a clubhead 28 is provided with a vertical triangular shaped highlight 30 (as illustrated in Figure 4B)
  • the highlight 30 is symmetric about the vertical when the clubhead 28 is in properly grounded position As the clubhead passes through the overlapping detection planes part of the highlight 30 extends beyond at least one of the two planes
  • Comparison of the signal waveforms V3, V4 allows an estimate of the height of the clubhead as it passes through the detection planes
  • the relative slope of the leading and trailing edges of the signal waveforms allows an estimate of the clubhead dynamic loft (i e rotation about the X axis)
  • two sensors 100, 101 are used with a single slit aperture as shown in Figure 9 and the clubhead is provided with a first highlight 30 on the toe as described above and a second highlight 30A on the hosel If the spacing between the sensors 100 101 corresponds to the length of the slit aperture eg both being around 15 mm the overlap region 103 will have parallel sides and if the width of this region is less than the vertical dimension of the highlight 30 this ensures that the signals received by the two sensors 100, 101 differ so information on the vertical position of the clubhead can be deduced therefrom As indicated above, measurement of the waveform produced by the highlight 30 allows the dynamic loft of the clubhead to be estimated The data received from the two highlights 30, 30A also enables the dynamic lie of the clubhead le its rotation about the Y axis to be estimated
  • typical waveforms for V3 and V4 show how height and tilt of the clubhead 28 can be measured
  • the rate of rise of the leading edges 104 105 of the waveforms are steeper than the respective trailing edges 106 107 and this indicates that the clubhead was de-lofted as it passed through the detection planes
  • the waveform shapes show that only a lower part of the highlight 30 passed through the field of view of sensor 100, and that most of the highlight, including the upper portion passed through the field of view of sensor 101 Detailed analysis of the waveforms allows precise measurement of the height and dynamic loft of the clubhead through the detection planes
  • PSD position sensitive detector
  • D is the separation between the aperture 142 and the photosensitive surface of the PSD
  • the emitters may instead be arranged to emit light only in a given plane and wide angle sensors used to detect when light is reflected from this plane
  • the light emitters define the detection plane e g by use of a slit aperture adjacent a light source, rather than the light sensors If more than one detection plane is used in this arrangement, it may be necessary to time complex the emitters to avoid signals from the different detection planes interfering with each other

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  • Length Measuring Devices By Optical Means (AREA)

Abstract

L'appareil comprend une ou plusieurs sources (18; 15) de lumière fournissant la lumière émise ou reflétée par le mobile et un ou plusieurs moyens (15; 12, 50, 51) de détection disposées de manière à émettre un signal lorsque ladite lumière vient les éclairer, un des moyens (15; 12, 50, 51) de détection au moins ayant été disposé de manière à détecter le moment où le mobile intercepte un plan (19, 20, 21, 64, 65, 66, 67) de détection connu, quel que soit l'endroit où le mobile intercepte le plan. Pour définir un plan de détection, les moyens de détection peuvent comprendre une ouverture (10, 11, 12, 23, 60, 61) en forme de fente et/ou des lentilles cylindriques. L'appareil peut être utilisé pour mesurer la position et/ou le mouvement précédant ou suivant l'impact d'une tête de club de golf (7) et/ou d'une balle de golf lors d'un coup de golf.
PCT/GB1997/002873 1996-10-19 1997-10-17 Appareil de mesure des parametres relatifs a la trajectoire et/ou au mouvement d'un mobile WO1998018010A1 (fr)

Priority Applications (4)

Application Number Priority Date Filing Date Title
GB9908258A GB2334781B (en) 1996-10-19 1997-10-17 Apparatus for measuring parameters relating to the trajectory and/or motion of a moving article
JP10519097A JP2001502428A (ja) 1996-10-19 1997-10-17 移動している物品の軌道及び／又は運動に関連するパラメータを測定するための装置
US10/090,363 US6887162B2 (en) 1996-10-19 2002-03-04 Apparatus for measuring parameters relating to the trajectory and/or motion of a moving article
US11/046,914 US20050130755A1 (en) 1996-10-19 2005-01-31 Apparatus for measuring parameters relating to the trajectory and/or motion of a moving article

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
GBGB9621828.4A GB9621828D0 (en) 1996-10-19 1996-10-19 Impact analysers for golf
GBGB9705589.1A GB9705589D0 (en) 1996-10-19 1997-03-18 Impact analysers for golf
GB9621828.4 1997-03-18
GB9705589.1 1997-03-18

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US29127399A Continuation-In-Part 1996-10-19 1999-04-14

Publications (1)

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WO1998018010A1 true WO1998018010A1 (fr) 1998-04-30

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PCT/GB1997/002873 WO1998018010A1 (fr) 1996-10-19 1997-10-17 Appareil de mesure des parametres relatifs a la trajectoire et/ou au mouvement d'un mobile

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Country Link
JP (1) JP2001502428A (fr)
GB (1) GB2334781B (fr)
WO (1) WO1998018010A1 (fr)

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DE102005046085A1 (de) * 2005-09-26 2007-03-29 Haag Elektronische Meßgeräte GmbH Messvorrichtung und Verfahren zur Messung von Treffmomentfaktoren eines Golfschlägers
GB2478059A (en) * 2010-02-18 2011-08-24 Norman Matheson Lindsay Determining motion of a projectile such as a golf ball
DE102005027593B4 (de) * 2004-06-14 2012-11-29 Hgm Gmbh - Haag Golf Messtechnik Vorrichtung und Verfahren zur Messung der Schlägerkopfgeschwindigkeit eines Golfschlägers
CN112699979A (zh) * 2021-01-04 2021-04-23 北京国腾联信科技有限公司 一种货物移动检测方法、装置及电子设备

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US6254492B1 (en) * 2000-08-02 2001-07-03 Michael Taggett Sports training system and sports video game
GB2411127A (en) * 2004-02-18 2005-08-24 Norman Matheson Lindsay Methods and systems using prediction of outcome for launched objects
KR101026518B1 (ko) 2009-04-07 2011-04-01 주식회사 위너골프텍 스크린 골프연습장용 센서장치
WO2011036774A1 (fr) * 2009-09-25 2011-03-31 富士通株式会社 Programme de génération de lieu et dispositif de génération de lieu
KR101826837B1 (ko) * 2016-08-12 2018-02-08 주식회사 골프존 볼의 비행정보 연산장치, 볼의 비행정보 연산방법 및 이를 기록한 컴퓨팅장치에 의해 판독 가능한 기록매체
KR102145590B1 (ko) * 2017-07-28 2020-08-28 하태호 스마트 거리 센서 바

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102005027593B4 (de) * 2004-06-14 2012-11-29 Hgm Gmbh - Haag Golf Messtechnik Vorrichtung und Verfahren zur Messung der Schlägerkopfgeschwindigkeit eines Golfschlägers
DE102005046085A1 (de) * 2005-09-26 2007-03-29 Haag Elektronische Meßgeräte GmbH Messvorrichtung und Verfahren zur Messung von Treffmomentfaktoren eines Golfschlägers
WO2007033664A2 (fr) 2005-09-26 2007-03-29 Hgm Gmbh Haag Golf-Messtechnik Dispositif de mesure pour mesurer des facteurs de moment d'impact d'une canne de golf et dispositif d'etalonnage pour mesurer des ecarts angulaires
DE102005046085B4 (de) * 2005-09-26 2007-08-16 Hgm Gmbh - Haag Golf Messtechnik Verfahren zur Messung von Treffmomentfaktoren eines Golfschlägers
US8142301B2 (en) 2005-09-26 2012-03-27 Hgm Gmbh - Haag Golf Messtechnik Measuring device for measuring hitting parameters of a golf club and associated calibration device
GB2478059A (en) * 2010-02-18 2011-08-24 Norman Matheson Lindsay Determining motion of a projectile such as a golf ball
CN112699979A (zh) * 2021-01-04 2021-04-23 北京国腾联信科技有限公司 一种货物移动检测方法、装置及电子设备

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GB2334781A (en) 1999-09-01
GB9908258D0 (en) 1999-06-02
JP2001502428A (ja) 2001-02-20

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