JP5034731B2 - Evaluation method of swing - Google Patents

Description

  The present invention relates to a swing evaluation method for classifying golf club swings of a golfer, and more particularly to a swing evaluation method for classifying a swing in consideration of the rotation of a golf club head.

Conventionally, the head speed has been widely used as a parameter characterizing a golfer's swing. This head speed represents the magnitude of the power of the entire swing, and depends on the arm strength of the golfer.
Further, as a parameter characterizing a golfer's swing, a grip turn is used in addition to the head speed, and a wrist turn ratio represented by a ratio between the head speed and the grip speed is proposed. This wrist turn ratio is a means for determining how to use the list immediately before the impact.
Thus, at present, there are two parameters that characterize the golfer's swing: head speed and wrist turn ratio.
A golf club corresponding to a golfer's swing is selected using these two parameters. However, depending on the golfer, even a golf club selected from two parameters may not always be sufficiently satisfactory. Thus, the swing behavior is analyzed in consideration of parameters other than the above two types (see Patent Document 1).

According to Patent Document 1, it is possible to analyze the head face surface at the time of impact without repeating the trial production and trial hitting of the golf club and taking into account the influence of the bending and twisting of the golf club. Further, a golf swing simulation method for obtaining an analysis result of a golf club with high accuracy is disclosed.
This Patent Document 1 measures the swing behavior of a golfer using the actual golf club, time history data of the coordinates of the grip of the golf club, time history data of the tilt angle of the grip, Obtain the time history data of the rotation angle of the grip around the shaft axis, which is the geometrical central axis, and give the golf club model a swing motion based on the above three time history data and consider the torsion of the golf club model Thus, the behavior of the golf club model is analyzed by simulation.
In Patent Document 1, it is possible to know the behavior of the golf club model, such as the deflection and twist of the shaft, the orientation of the face surface of the head of the golf club model at the time of impact, and once the swing data of each golfer is taken, It is disclosed that each golfer can select a golf club corresponding to an individual swing by using a simulation result without swinging the actual object.

JP 2002-331060 A

In Patent Document 1, as a parameter characterizing a golfer's swing, the direction of the face surface of the head at the time of impact is analyzed in consideration of the effect of torsion around the shaft axis. However, in the golf club shaft, the twist at the tip of the golf club head is delayed with respect to the vicinity of the grip, so that the direction of the face surface at the time of impact can be determined simply by considering the torsion around the shaft axis. It is difficult to analyze and it is necessary to actually measure. For this reason, in patent document 1, each golfer cannot necessarily select the golf club according to each swing.
Thus, as a parameter characterizing the swing of the golfer for analyzing the swing of the golf club, the torsion around the shaft axis is considered, but simply measuring the torsion around the shaft axis is suitable for the golfer. It is not always possible to select a golf club. Furthermore, the relationship between the torsion around the shaft axis and the swing characteristics is unknown, and no method has been proposed for discriminating the golfer's swing characteristics from the torsion around the shaft axis.

  An object of the present invention is to provide a swing evaluation method for solving the problems based on the above-described prior art and classifying the swing in consideration of the rotation of the golf club head.

  In order to achieve the above object, the present invention provides a golf club swing evaluation method having a golf club head provided with a hosel part to which a golf club shaft is mounted at a crown part, wherein the golf club head is In a state where the golf club shaft is disposed on a horizontal plane, two points at least 10 mm apart on an intersecting line that includes the axis of the golf club shaft and intersects the plane perpendicular to the horizontal plane and the crown portion of the golf club head. The present invention provides a swing evaluation method characterized by measuring the speed of a golf club during a swing and evaluating the swing based on the speed of each point.

In the present invention, it is preferable that a difference in speed between the points is used for the evaluation of the swing pattern.
In the present invention, it is preferable that the evaluation of the swing pattern uses a speed ratio of each point.
Further, in the present invention, the evaluation of the swing pattern may use a ratio represented by δ / H, where H is the head speed during the swing and δ is the speed difference between the points. preferable.
In the present invention, it is preferable to use a ratio represented by δ / H rather than the difference between the two speeds and the ratio of the two speeds in the evaluation of the swing pattern.
In this case, the head speed H may be measured by another measuring means different from that for measuring the speed at two points, and the average speed of the two speeds may be used as the head speed H.

According to the swing evaluation method of the present invention, in a state where the golf club head is installed on a horizontal plane, a plane that includes the axis of the golf club shaft and is orthogonal to the horizontal plane intersects with the crown portion of the golf club head. The speed at the time of swing of the golf club is measured at two points at least 10 mm apart on the line, and the speed of each point is obtained. Based on the speed of each point, the golf club shaft of the golf club head during the swing can be distinguished from the rotation axis and the degree of rotation, so that the swing can be evaluated.
Here, the golf club head has a different (different) rotational moment about the golf club shaft axis depending on the position of the center of gravity. In the present invention, it is further possible to select a golf club head having an appropriate specification (specification) for each classified swing by evaluating the swing and classifying the swing. Thus, the appropriateness of the golf club head (the center of gravity position of the golf club head) can be determined for each swing.
Here, some golf club shafts have different (different) rigidity and torque. In the present invention, furthermore, a golf club shaft having an appropriate specification (specification) can be selected for each classified swing by evaluating the swing and classifying the swing. In this way, it is possible to determine the appropriateness of the rigidity and torque of the golf club shaft for each swing.

The swing evaluation method of the present invention will be described in detail below based on preferred embodiments shown in the accompanying drawings.
The present inventor has found that the ratios described below can characterize a golfer's swing, in addition to the head speed and wrist turn ratio that characterize a conventional golfer's swing. Hereinafter, the knowledge of the present invention will be described.

  In the present invention, as shown in FIG. 1, for example, a golf club 10 having a golf club head 12, a golf club shaft 14, and a grip 16 is used.

The golf club head 12 has a face portion 20, a sole portion 22, a crown portion 24, a side portion 26 and a hosel portion 28. In the golf club head 12, an outer shell structure is configured by the face portion 20, the sole portion 22, the crown portion 24, and the side portion 26, and the sole portion 22 is on the lower side and faces the sole portion 22. A crown portion 24 is provided, and a side portion 26 and a face portion 20 are provided between the sole portion 22 and the crown portion 24.
The face portion 20 has a face surface 20a for hitting a golf ball. A hosel portion 28 is provided in the crown portion 24.

  As the golf club shaft 14, for example, a hollow one made of a metal or alloy (steel), or a fiber reinforced composite material such as FRP or CFRP is used.

In the golf club 10, the golf club shaft 14 is attached to the hosel portion 28 of the golf club head 12 via a socket 18. The golf club shaft 14 has a grip 16 attached to the opposite side to which the golf club head 12 is attached.
The central axis of the golf club shaft 14 of the golf club 10 is referred to as a shaft axis S.
Further, the golf club shaft 14 may be directly attached to the hosel portion 28 without the socket 18 being interposed.

Further, as shown in FIG. 2A, in the state where the golf club head 12 is installed on the horizontal plane B, the plane Ps including the shaft axis S and orthogonal to the horizontal plane B, and the crown of the golf club head 12 are included. On the intersection line E where the part 26 intersects, for example, two markers 30a and 30b are provided with a distance D of at least 10 mm. The interval between the two markers 30a and 30b is 60 mm. The marker 30a is provided on the hosel portion 28 side, that is, the heel side, and the marker 30b is provided on the toe side.
Furthermore, both the marker 30a and the marker 30b are provided with a marker 30c, for example, at a position that becomes a vertex of a triangle. The marker 30c is provided on the side opposite to the face surface 20a with respect to the intersection line E.

In the present invention, the speeds of the markers 30a and 30b and the marker 30c when the golf club 10 is swung are measured.
Note that the speed of the marker 30a is the heel side speed (Sh), the speed of the marker 30b is the toe side speed (St), and the speed of the marker 30c is the head speed (H).
Also, the golf club 10, as shown in FIG. 1, a line V _G parallel to the shaft axis S with passing through the center of gravity G of the golf club head 12, the distance G _L between the shaft axis S are used two different .

Of the two types of golf clubs, one has a mass of the golf club head 12 of 196.2 g, a volume of 463 cc (cm ³ ), a lie angle β of 60.5 °, and a loft angle θ (see FIG. 2B). ) Is 11.5 °, the distance G _L (see FIG. 1) is 44.4 mm, the center-of-gravity retraction amount G _R (see FIG. 2B) is 15.6 mm, and passes through the center of gravity G and is perpendicular to the horizontal plane B. The magnitude of the moment of inertia M (see FIG. 1) around the rotation axis with V as the rotation axis is 4286 g · cm ² .

Note that the distance G _L, a first plane containing a straight line parallel to V _G and as the shaft axis S of the center of gravity G of the golf club head 12 shown in FIG. 1 (not shown), first comprises a shaft axis S 2 Is the length between the first plane and the second plane when the plane (not shown) is parallel.
Further, the center of gravity retraction amount G _R, as shown in FIG. 2 (b), is that the distance in the horizontal plane B parallel to the direction of the shaft axis S, the straight line V passing through the center of gravity G.

Of the two types of golf clubs used, the remaining golf club head 12 has a mass of 196, 0 g, a volume of 461 cc, a lie angle β of 59.9 °, and a loft angle θ (see FIG. 2B) of 11. .1 °, distance G _L (see FIG. 1) is 36.9 mm, center of gravity retraction amount G _R (see FIG. 2B) is 15.8 mm, and moment of inertia M (see FIG. 1) is 4109 g · cm ² .
Note that the two types of golf clubs 10 used have different distances _GL . The shorter the distance _GL , that is, the closer the position of the center of gravity G is to the shaft axis S, the easier the golf club head 12 rotates about the shaft axis S.

Five test subjects were allowed to swing two types of golf clubs, and the heel side speed Sh, the toe side speed St, and the head speed H were measured for each golf club. A method for measuring the speed of each marker 30a, 30b, and 30c will be described in detail later.
Difference δ between heel side speed Sh and toe side speed St, ratio of heel side speed Sh to toe side speed St, head speed H during swing, heel side speed Sh and toe side speed When the difference from St is δ, a ratio represented by δ / H (hereinafter referred to as rolling ratio R) was obtained. These results are shown in FIGS. 3 (a), (b) and (c). Note that in the bar graph shown in FIG. 3 (a), (b), (c), hatched bars, (see FIG. 1) the distance _{G L} represents short, the remaining rods, the distance _{G L} (FIG. 1 Reference) indicates a long one.

As shown in FIGS. 3A, 3B, and 3C, the difference δ between the heel side speed Sh and the toe side speed St without depending on golf clubs having different distances _GL , Each of the ratio of the speed Sh and the toe side speed St and the rolling ratio R showed a different tendency for each subject.
The difference δ between the heel side speed Sh and the toe side speed St, the ratio between the heel side speed Sh and the toe side speed St, and the rolling ratio R are all inherent to the swing. It is believed that there is.
The inventor of the present application, among the difference δ between the heel side speed Sh and the toe side speed St, the ratio between the heel side speed Sh and the toe side speed St, and the rolling ratio R, in particular, the rolling ratio R Pay attention.

When the relationship between the rolling ratio R and the head speed H that indicates the characteristics of the swing was examined, as shown in FIG. 4, the rolling ratio R had a low correlation with the head speed H. .
Further, when the relationship between the rolling ratio R and the wrist turn ratio that indicates the characteristics of the swing was examined, as shown in FIG. 5, the rolling ratio R has a low correlation with the wrist turn ratio. there were.
The wrist turn ratio is obtained by calculating the speed at the lower end portion 32a of the grip 16 shown in FIG. 1 at the time of swing and the speed at the upper end portion 32b of the hosel portion 28 at the time of swing, and obtaining the ratio of these speeds. It is. The speed of the lower end portion 32a of the grip 16 and the speed of the upper end portion 32b of the hosel portion 28 during the swing are measured by known methods.

  Thus, it has been found that the rolling ratio R has a low correlation with the head speed and wrist turn ratio, which are parameters that characterize the golfer's swing, and may be used as a parameter that characterizes the golfer's swing.

Further, the inventor of the present application focused on the difference in head speed between two types of golf clubs in the same subject.
The difference between the head speed and the distance G _L is the distance G _L from the head speed of a long golf club is minus the head speed of a short golf club.
As a result of investigating the relationship between the head speed difference and the head speed H indicating the swing characteristics, the correlation was low as shown in FIG.
Further, when the relationship between the head speed difference and the wrist turn ratio indicating the characteristics of the swing was examined, the correlation was low as shown in FIG.
Further, when the relationship between the head speed difference and the rolling ratio R was examined, the correlation was high as shown in FIG.

The golf club head speed H is obtained by the sum of the speed of translational movement of the golf club head 12 and the speed of rotational movement of the golf club head 12.
Further, the longer the distance _GL , the more difficult it is to rotate the golf club head 12, and when the same subject swings, the golf club having a longer distance _GL tends to have a slower head speed H.
Furthermore, golfers who tend to rotate the golf club head 12 tend to have a slower head speed H because a golf club with a longer distance _GL is more difficult to rotate the golf club head 12.
For this reason, the head speed difference in golf clubs having different distances _GL differs depending on the degree of rotation of the golf club head 12 in the rotation direction Rs (see FIG. 1) with the shaft axis S as the rotation axis during swing.

A golfer who tends to rotate the golf club head 12 tends to have a larger head speed difference. Since the head speed difference and the rolling ratio R are highly correlated, the rolling ratio R can represent the degree of rotation of the golf club head 12. Moreover, since the rolling ratio R does not depend on the distance _GL of the golf club head, it is sufficient to swing one golf club, and it is not necessary to swing a plurality of golf clubs having different distances _GL .
As described above, the present inventor has found that the degree of rotation of the golf club head can be represented by the rolling ratio R, and has found that the rolling ratio R can indicate the characteristics of the swing of the golf club. It was. The rolling ratio R indicates a rotational operation around the shaft axis S of the golf club shaft 14, and the greater the rolling ratio R, the greater the degree of rotation of the golf club head.
The evaluation of the swing of the present invention is made based on the above knowledge.

The swing evaluation method of the present invention will be described in detail below.
In the present invention, as shown in FIG. 2 (a), in a state where the golf club head 12 is installed on the horizontal plane B, the golf club head includes the plane Ps including the shaft axis S and orthogonal to the horizontal plane B. On the intersection line E where the 12 crown portions 26 intersect, the speed at the time of swing is obtained for each of the two points having a distance D of at least 10 mm.
In addition to these two points, the head speed is also measured, and finally the rolling ratio R is calculated.
The distance D between the two points on the golf club head is at least 10 mm. This is because when the distance D is less than 10 mm, the speed difference is small and the rotation of the golf club head is not sufficiently reflected.

In the swing evaluation method of the present invention, as described above, by calculating the rolling ratio, for example, the degree to which the golf club head 12 is rotated about the shaft axis S can be classified for the golfer's swing. it can.
For example, when the rolling ratio is small, it can be determined that there is a tendency to hit the body turn without using the wrist. On the other hand, when the rolling ratio is large, it can be determined that there is a tendency to hit using the wrist more than the body turn. That is, the swing can be evaluated and the swing can be classified.

In addition to this, the golf club head 12 rotates about the shaft axis S depending on the rigidity and torque of the golf club shaft 14 (the degree of rotation varies). It is also possible to determine the appropriateness of rigidity and torque. As a result, in the present invention, it is possible to select a golf club shaft having an appropriate specification (specification) for each classified swing, and in this way, to determine the appropriateness of the rigidity and torque of the golf club shaft for each swing. be able to.
Here, the golf club head 12 has a different (different) rotational moment about the shaft axis S depending on the position of the center of gravity. In the present invention, the golf club head 12 having an appropriate specification (specification) can be selected for each classified swing by calculating the rolling ratio R, evaluating the swing, and classifying the swing. Thus, in the present invention, the appropriateness of the golf club head (the position of the center of gravity of the golf club head) can be determined for each swing.

Hereinafter, an embodiment of a measuring device for measuring various speeds such as a head speed of a golf club head used in the swing evaluation method of the present invention will be described.
FIG. 9A is a schematic view showing a measuring device for measuring the speed of the golf club head used in the swing evaluation method of the present invention. FIG. 9B is a block diagram showing a processing configuration of a computer used in a measuring device that measures the speed of the golf club head used in the swing evaluation method of the present invention.
A golf club head behavior measuring device 40 (hereinafter referred to as a measuring device 40) shown in FIGS. 9A and 9B is a golf ball in which the golfer 34 holds the golf club 10 and strikes the golf ball b in the hitting direction a. It is an apparatus for measuring the behavior of a golf club head before and after launching a golf ball b during swing.

  The measuring device 40 captures image data of images captured by the cameras 42 and 44, the illumination light sources 46 and 48, the control device 50 that controls the cameras 42 and 44 and the illumination light sources 46 and 48, and the cameras 42 and 44. A computer 52 that performs processing and image processing, and a monitor 66 and an operation system 68 connected to the computer 52 are configured.

The camera 42 and the illumination light source 46 are arranged in a forward upward direction from a position facing the golfer 34 so as to photograph the golf club head 12 before and after the golf ball b is launched, and the golf club head 12 illuminated by the illumination light source 46 is used. Is photographed by the camera 42. The camera 44 and the illumination light source 48 are disposed rearward and upward from a position facing the golfer 34 so as to photograph the golf club head 12 before and after launching the golf ball b, and the golf club head 12 illuminated by the illumination light source 48. Is photographed by the camera 44.
In this embodiment, the golf club head 12 before and after launching the golf ball b is photographed from two different directions. In the present invention, at least two different directions such as three different directions, four directions,... The golf club head 12 may be photographed.
The arrangement positions of the camera and the illumination light source are not particularly limited as long as the golf club head 12 can be photographed from at least two different directions. For example, the camera 42 and the illumination light source 46 are arranged in the upper front direction facing the golfer 34 across the tee for teeing up the golf ball b, while the camera 44 and the illumination light source 48 are rearward from the position facing the golfer 34. It may be arranged in the upward direction. Further, the camera 42 and the illumination light source 46 may be arranged in the upper front direction from the position facing the golfer 34, and the camera 44 and the illumination light source 48 may be arranged in the upper front direction at a position facing the golfer 34.
As the cameras 42 and 44, for example, a high-speed video camera or a high-speed shutter camera that captures images at a time interval of 1/1000 second is used.
The illumination light sources 46 and 48 are, for example, a strobe or an infrared projector, and are provided along with the cameras 42 and 44.

On the golf club head 12 of the golf club 10, the two markers 30a and 30b are provided on the intersection line E with an interval D of at least 10 mm as described above. Furthermore, the marker 30c is provided so that the vertex of a triangle may be arrange | positioned with marker 30a, 30b.
For example, the markers 30a, 30b, and 30c recursively reflect the illumination light of the illumination light sources 46 and 48 in the illumination direction so that the markers 30a, 30b, and 30c can always be identified in the images taken by the cameras 42 and 44. It has a configuration having a reflection function. For example, the markers 30a, 30b, and 30c are obtained by cutting a known retroreflective sheet into a predetermined shape.

Here, the marker feature point is a point that characterizes the marker, and the position of the marker feature point is extracted on the three-dimensional coordinate system from an image obtained by photographing one marker from two or more different directions.
For example, when the marker has a circular shape, the center point of the circular shape is set as the marker feature point, and the position is extracted by the image processing unit 56 described later. Further, when the marker has, for example, an equilateral triangle shape, the center of gravity of the equilateral triangle shape or three vertices (intersection points of three sides) are used as marker feature points, and the positions are extracted. In the present invention, the shape of the marker is not particularly limited as long as it is one or more points that characterize the marker and that can be uniquely extracted.

  The control device 50 controls the cameras 42 and 44 so that the cameras 42 and 44 continuously shoot at regular intervals at the same time, and turns on the illumination light sources 46 and 48 such as strobes accordingly. It is a device to control. Further, the control device 50 AD-converts image signals obtained by continuously capturing images with the cameras 42 and 44 into digital image data, and stores the image data in the memory after performing dark correction on the image data. Have The image data of continuously captured images is called from the memory and supplied to the computer 52 described later.

The computer 52 specifies the position of each marker feature point of each marker 30a, 30b, 30c from the image data of the golf club head 12 during the golf swing, and the behavior of the golf club head 12 using this specified position. Is calculated.
Specifically, the computer 52 includes a signal processing unit 54, an image processing unit 56, an analysis unit 58, an output unit 60, a CPU 62, and a memory 64, and is connected to a monitor 66 and an operation system 68.
The signal processing unit 54, the image processing unit 56, the analysis unit 58, and the output unit 60 are portions that function by executing a program. In the present invention, these portions are configured by hardware such as a circuit. It may be a thing.

  For example, only the data values of the portions of the markers 30a, 30b, and 30c are the data values of the other portions so that the signal processing unit 54 can extract the marker feature points from the markers 30a, 30b, and 30c in the image. As shown in FIG. 5, the image data is subjected to brightness correction and contrast correction under predetermined processing conditions, and further subjected to binarization.

  The image processing unit 56 is a part that specifies the position of the marker feature point from the image data of the golf club head 12 during the golf swing, and calculates the behavior of the golf club head 12 using the specified position. The image processing unit 56 uses an extraction unit 56a that identifies each marker feature point of each of the markers 30a, 30b, and 30c and extracts a position in the three-dimensional coordinate system, and a three-dimensional coordinate position of each extracted marker feature point. And a calculation unit 56b for calculating time-series data of the position and orientation of the golf club head 12.

The extraction unit 56a identifies the portions of the markers 30a, 30b, and 30c from the binarized image, extracts their positions, and is taken by the cameras 42 and 44 at the same time, and different directions at the same time. The position coordinates of each marker feature point of each marker 30a, 30b, 30c in the image photographed from the above are obtained, and the space through which the golf club head 12 passes is determined using the obtained position coordinates of each marker feature point. The position coordinate in the three-dimensional coordinate system is obtained, and the position of each marker feature point in the three-dimensional coordinate system is extracted.
Since the shooting directions of the cameras 42 and 44 are known, the information representing the two-dimensional position coordinates in the images shot by these cameras 42 and 44 is obtained, thereby representing a space through which the golf club head 12 passes. The position in the three-dimensional coordinate system (three-dimensional position coordinates) can be obtained.

For example, when the images of the markers 30a, 30b, and 30c are taken at a time interval of 1/1000 second, the three-dimensional positions of the marker feature points of the markers 30a, 30b, and 30c every 1/1000 second, for example. Coordinate time series data can be obtained. Of course, since each marker 30a, 30b, 30c is provided, for example, at three locations on the crown portion 24 of the golf club head 12, the three-dimensional position coordinates of the three marker feature points are obtained.
FIG. 10 is a schematic diagram showing a time history of marker movement at a time interval of 1/1000 second determined from the three-dimensional position coordinates of the marker feature point. In the XYZ coordinate system, the golf ball launch direction is the X direction, the direction orthogonal to this direction, the direction parallel to the ground as the Y direction, and the direction perpendicular to the ground as the Z direction in FIG. is there. Point ε is the launch position of the golf ball.
Since the head speed of a golf club head is usually 30 to 50 (m / sec), the golf club head moves 3 to 5 (cm) in 1/1000 second. In FIG. 10, three plot groups M ₁ , M _{2 to} M ₁₀ representing three markers indicate the positions of three marker feature points extracted from markers photographed at a time interval of 1/1000 second. Thus, the change in the position of the golf club head and the orientation of the face can be known from the position of the marker feature point.

The calculation unit 56b is a part that calculates the position and orientation of the golf club model as time series data from the three-dimensional position coordinates obtained by the extraction unit 56a.
Specifically, the data (CAD data) of the three-dimensional shape model of the golf club head and information on the position of the corresponding point on the three-dimensional shape model corresponding to the arrangement position of the marker feature point are stored in the memory 64 in advance. The stored data and information are called, and the position coordinates of the corresponding points on the three-dimensional shape model in the three-dimensional coordinate system coincide with the three-dimensional position coordinates of the marker feature points extracted by the extraction unit 56a. As described above, the position and orientation of the three-dimensional shape model are calculated, and the time series data of the position and orientation of the golf club head are calculated using the position and orientation as the position and orientation of the golf club head.

The analysis unit 58 uses the time series data of the calculated position and orientation of the golf club head to identify the hitting position of the golf ball on the hitting surface of the golf club head, the head speed H at this hitting position, the toe side This is a part for calculating the speed St and the heel side speed Sh. That is, the heel side speed Sh is calculated using the time series data of the marker 30a, the toe side speed St is calculated using the time series data of the marker 30b, and the time series data of the marker 30c is used. A head speed H is calculated.
The analysis unit 58 also calculates the rolling ratio R from the head speed H, the toe side speed St, and the heel side speed Sh.
In the present embodiment, for example, the hit position of the golf ball on the hitting surface of the golf club head can be specified with an accuracy within ± 0.5 (mm), for example. Further, the head speed H, the toe side speed St, and the heel side speed Sh at the hitting point position can be calculated, and changes in the head speed H, the toe side speed St, and the heel side speed Sh, respectively. Can be calculated with an accuracy within ± 0.5 (m / sec), for example.

  The golf club head 12 during the golf swing moves in a substantially circular orbit, and a centrifugal force acts on the center of gravity G of the golf club head 12 at this time. On the other hand, although the golf club head 12 is supported by the golf club shaft 14, the support position by the golf club shaft 14 and the position of the center of gravity of the golf club head 12 do not coincide with each other. A moment acts on the golf club head 12 due to the centrifugal force acting on the golf club. The effective loft angle of the golf club head 12 refers to the loft angle when the orientation of the face surface 20a (striking surface) of the golf club head 12 is changed by this moment. Of course, in addition to the effective loft angle, the lateral direction of the striking surface such as whether the striking surface immediately before launching is open or closed can also be known.

  The output unit 60 outputs a calculation result such as the head speed H, the toe side speed St, the heel side speed Sh, or the effective loft angle at the calculated hitting position of the golf ball b to an external device (not shown) such as a printer. Is instructed to output.

The CPU 62 is a part that manages and controls each function of the computer 52, and the memory 64 is a part that stores and holds the above-described image data, CAD data, and calculation results calculated in each part.
The monitor 66 is an image photographed by the cameras 42 and 44, a signal-processed image, a time history of marker movement as shown in FIG. 10, a three-dimensional shape model, or a golf club represented using a three-dimensional shape model. The behavior of the head and the like are displayed, and further, the input screen for setting the processing conditions to be applied to the image and the results obtained in each part are displayed.
The operation system 68 is a mouse or a keyboard, and is used for various input settings such as setting of processing conditions to be applied to an image and setting of a display screen displayed on the monitor 66.

In the present embodiment, the crown portion 24 of the golf club head 12 is provided with at least two or more markers 30a, 30b, 30c having a circular shape from which a center point is extracted as a marker feature point.
The golf club head 12 is placed in a predetermined address state. In this state, images at rest are taken by the cameras 42 and 44, and the three markers 30a, 30b, and 30c of the golf club head 12 are picked up by the extraction unit 56a of the computer 52. The information on the arrangement position is accurately obtained. The information on the arrangement position is stored in the memory 64 as a corresponding point on the three-dimensional shape model constituted by CAD data. The arrangement position information is, for example, three-dimensional position coordinates with the center of gravity G position of the golf club head 12 as the origin.
The information on the arrangement positions of the three markers 30a, 30b, and 30c on the golf club head 12 is obtained more accurately by using a three-dimensional shape measuring instrument that uses a laser beam different from the measuring device 40, and the computer. 52 may be stored in advance in the memory 64.

Next, the golfer 34 grips the golf club 10 provided with the markers 30a, 30b, and 30c to perform a golf swing, and the golf club head 12 before and after launching the golf ball b in the golf swing is moved to the camera 42, Taken at 44.
The images photographed by the cameras 42 and 44 are subjected to predetermined processing and supplied to the image processing unit 56 as digital image data.
The image processing unit 56 extracts the positions of the marker feature points of the markers 30a, 30b, and 30c as three-dimensional position coordinates in the XYZ coordinate system from the image data of the golf club head 12 during the golf swing.
Next, the three-dimensional position coordinates in the XYZ coordinate system of the three corresponding points corresponding to the arrangement positions of the marker feature points of the three markers 30a, 30b, 30c on the three-dimensional shape model reproducing the golf club head 12 are as follows: The time-series data of the position and orientation of the three-dimensional shape model is calculated so that both coincide with the three-dimensional position coordinates of the marker feature points. This time series data is the time series data of the position and orientation of the golf club model.

From the calculated time series data, the golf ball hitting position on the face 20a (striking face) of the golf club head 12 is identified, the head speed H at this hitting position, the toe side speed St, and the heel side speed Sh. In addition, at least one of the calculation of the rolling ratio R and the calculation of the effective loft angle of the golf club head 12 is performed according to an instruction from the operator.
Finally, the golf swing of the golfer is classified from the calculated rolling ratio R as necessary.

  As described above, the measuring device 40 uses the information on the position of the corresponding point corresponding to the arrangement position of the marker feature point on the model and the three-dimensional shape model configured by CAD data reproducing the golf club head. To calculate the position and orientation of the three-dimensional shape model so that the position coordinates of the corresponding points on the three-dimensional shape model coincide with the three-dimensional position coordinates of the marker feature points extracted from the measured markers. The head speed H, the toe side speed St, the heel side speed Sh, and the rolling ratio R can be calculated.

  In addition, since the position and orientation of the golf club head can be displayed on the monitor 66 using a three-dimensional shape model, it is possible to reproduce and display the behavior of the golf club head from various directions that have not been conventionally seen. it can. In addition, since the golfer can visually see the behavior of the golf club head due to his / her golf swing as a moving image from various directions, the golfer can easily understand the characteristics of his / her golf swing.

In the present embodiment, the head speed H, the toe side speed St, and the heel side speed Sh are calculated using the data (CAD data) of the three-dimensional shape model, and further the rolling ratio R is calculated. be able to. For this reason, the speed of any point other than the marker position can also be calculated. Accordingly, the two markers are provided on the intersection line E with at least a gap D of 10 mm, but the present invention is not limited to this.
For example, the head speed H, the toe side speed St, and the heel side speed Sh may be calculated using arbitrary points on the golf club head, and further the rolling ratio R may be calculated.
Furthermore, a marker is provided on a predetermined line of the golf club head, and using the provided marker, the head speed H, the toe side speed St, and the heel side speed Sh are calculated, and further the rolling ratio R is calculated. May be.

In addition, in this invention, you may show to Fig.11 (a)-(e) besides the form of the circular markers 30a, 30b, 30c of this embodiment. In any form of marker, two markers are provided on the intersection line E with an interval D of at least 10 mm.
For example, as shown in FIGS. 11A and 11B, regular polygons such as regular triangular markers 70a, 70b, and 70c, square markers 72a, 72b, and 72c can be used. Here, in the case of each regular polygon, the positions of the marker feature points 71a to 71c and 73a to 73c extracted from the markers 70a to 70c and 72a to 72c can be the center points (centroid points) of the markers. Further, the shape of the marker is not limited to a regular polygonal shape, and may be, for example, an isosceles triangle shape, and the position of the marker feature point extracted from the marker may be, for example, the vertex of the isosceles triangle.
Moreover, the shape of each marker does not need to be the same, The thing of the above-mentioned shape can also be combined freely. As a combination, for example, as shown in FIG. 11C, two circular markers 74a and 74b and one equilateral triangular marker 74c may be used. Also in this case, the marker feature points 75a to 75c of the markers 74a to 74c are, for example, the center point (center of gravity) of the marker.

  Furthermore, a plurality of marker feature points may be extracted from one marker according to the marker shape. Here, as a marker and a plurality of marker feature points that can be extracted from the marker, for example, when the marker shape is an equilateral triangle, the marker feature point is the middle point of three vertices or three sides, When the shape is rectangular, the marker feature points are the four vertices or the midpoints of the four sides.

FIGS. 11D and 11E are schematic diagrams illustrating an example of a marker in which three marker feature points are extracted from one marker.
As shown in FIG. 11D, for example, the marker 76 has a regular triangular shape, and the three vertices of the marker 76 are marker feature points.
As shown in FIG. 11E, the marker 78 may be an isosceles triangular shape formed of a retroreflective sheet or the like, and the vertexes of the marker 78 may be extracted as marker feature points 78a to 78c. In the case of the marker 78 having an isosceles triangle shape, even when the captured image of the golf club 78 is affected by noise and the outline of the marker 78 is disturbed, the measuring device automatically recognizes the marker graphic, The positions of the vertices, that is, the positions of the marker feature points 78a to 78c can be specified.
In addition to pasting the above-mentioned retroreflective sheet, the method of providing a marker can use the coating of a retroreflective material, the fitting of a retroreflective member, etc., for example.

Furthermore, as shown in FIG. 12 (a), the marker 80 has an arm portion extending from one point in three directions, and a circular end at the end of the arm portion as in the marker 82 shown in FIG. 12 (b). A part may be provided. In the case of the marker 80 shown in FIG. 12A, for example, the ends of the arm portions are set as marker feature points 80a to 80c. In this case, the marker 80 is arranged so that the feature points 80a and 80b are on the intersection line E, and the distance D between the feature points 80a and 80b is at least 10 mm.
In the case of the mark 82 shown in FIG. 12B, for example, the center point of the end is set as the marker feature points 82a to 82c. In this case, the marker 82 is arranged so that the feature points 82a and 82b are on the intersection line E, and the distance D between the feature points 82a and 82b is at least 10 mm.
Furthermore, in consideration of design, marks such as various characters, figures and symbols may be used as markers.

Furthermore, a marker is a combination of one in which one marker feature point is extracted from one marker and one in which a plurality of marker feature points are extracted from one marker, or a plurality of marker feature points from one marker. It can also be a combination of what is extracted.
For example, in the marker 84 shown in FIG. 12C, a marker 84b from which one marker feature point 85c is extracted and a circular marker from which one marker feature point is extracted are connected in pairs. This is a combination of a marker 84a from which two marker feature points 85a and 85b are extracted. In this case, the marker 84 is provided so that the two marker feature points 85a and 85b are arranged on the intersection line E.
In FIG. 12D, the marker 86 is a combination of a marker 86b from which one marker feature point 87c is extracted and a marker 86a from which two marker feature points 87a and 87b are extracted to form an isosceles triangle. Is. In this case, the marker 86 is provided so that the two marker feature points 87a and 87b are arranged on the intersection line E.

  As described above, three or more marker feature points are extracted from an image obtained by photographing various markers provided on the golf club head 152 from two or more directions, and corresponding points on the three-dimensional shape model reproducing the golf club head are extracted. The position and orientation of the three-dimensional shape model are calculated so that the position matches the position of the extracted marker feature point. Thus, time series data of the position and orientation of the three-dimensional shape model reproducing the behavior of the golf club head is calculated, and the head speed H, the toe side speed St, the heel side speed Sh, and the rolling ratio R are calculated. be able to.

In the present embodiment, for example, the measurement device 40 is used to measure the head speed H, the toe side speed St, and the heel side speed Sh of the golf club head 12 when the golf club 10 swings, and further rolling. The ratio R is calculated. As a result, the swing of the golfer 34 can be classified because the magnitude of the amount by which the golf club head 12 is rotated about the shaft axis S as the rotation axis is known.
Further, since the measuring device 40 also measures the head speed H, the golfer's swing can be classified based on the head speed H and the rolling ratio.
Furthermore, the rotation of the golf club head 12 around the shaft axis S is also affected by the rigidity and torque of the golf club shaft 14. For this reason, the rigidity and torque of the golf club shaft 14 can also be evaluated. Thereby, a golf club shaft can also be selected according to a golfer's swing.

Hereinafter, other embodiments of a measuring device for measuring various speeds such as the head speed of a golf club head used in the swing evaluation method of the present invention will be described.
FIG. 13 is a schematic diagram showing a measuring device for measuring the speed of the golf club head used in the swing evaluation method of the present invention.
In another measuring apparatus 100 that measures the speed of the golf club head 12 used in the swing evaluation method of the present invention, a golfer 34 standing on the ground (horizontal plane) holds the golf club 10 as shown in FIG. For the golf swing to be performed, the posture of the golf club head 12 in the impact state is analyzed, and the toe side speed St, the heel side speed Sh, and the head speed H of the golf swing are measured in the golf swing, and further the rolling ratio R Is calculated.

  The measuring apparatus 100 includes a swing measurement / data processing unit 110 (hereinafter referred to as a unit 110) and a computer 120.

  The golf club 10 gripped by the golfer 34 is, for example, within a range of a length of 1066 to 1219 mm (about 42 to about 48 inches), a frequency of 3.3 to 5.0 Hz (200 to 300 cpm), and a mass of 280 to 320 g. Standard golf clubs with standard specifications.

FIG. 14 is an enlarged schematic view showing the golf club head 12 included in the golf club 10. Two measurement points are provided on the crown portion 24 of the golf club head 12 along the intersection line E with an interval D of at least 10 mm. A reflection marker 116a described later is provided at each measurement point. And 116b are respectively provided.
As will be described later, the heel side speed Sh is obtained by measuring the reflective marker 116a, and the toe side speed St is obtained by measuring the reflective marker 116b.

  FIGS. 15A and 15B are schematic views for explaining the behavior of the golf club head in the impact state of the golf swing, and correspond to a projection view of the golf club head 12 viewed from the upper side of the ground. Yes. As described above, the degree of rotation of the golf club head 12 with respect to the shaft axis S differs depending on the golfer. FIGS. 15A and 15B show the posture of the golf club head 12 in the impact state. It is.

  In the measurement apparatus 100, in the projection views shown in FIGS. 15A and 15B, a passage reference line (first passage reference line 117s) that is substantially horizontal to the ground and substantially perpendicular to the moving direction of the golf club head 12 in the impact state. The second passage reference line 119s) is set in advance within a range (impact range) through which the golf club 10 passes in the impact state. Specifically, two planes that are perpendicular to the ground (horizontal plane) on which the golfer 34 stands and are parallel to each other are set in advance. The golfer 34 holds the golf club head 12 so that it passes through the two planes in the impact state, and the two planes and the movement direction of the golf club head 12 are substantially perpendicular when passing. Do golf swing. Each passage reference line (the first passage reference line 117s and the second passage reference line 119s) corresponds to a line of intersection between the two planes and the surface formed by the crown portion 24 in the golf swing performed by the golfer 34. Such a passage reference line is defined by projection light projected from the unit 110 and a light receiving surface of a line sensor 150 described later. The surface formed by the crown portion 24 in the golf swing is a surface substantially coinciding with the locus of the crown portion 24 in the golf swing (that is, in the golf swing, the crown portion 24 moves along this surface). ). For example, when the launch target direction of the golf ball is determined in advance, the passing reference line is set substantially perpendicular to the direction of the vector orthogonally projected from the tee position to the launch target direction of the golf ball on the ground. Good.

  In general, the direction of a vector obtained by orthogonally projecting the normal vector of the face surface of the golf club head in the address state onto the ground and the moving direction of the golf club head in the impact state substantially coincide. For example, the golfer 34 performs golf swing by setting the normal vector of the face surface of the golf club head in the address state so that the direction of the vector orthogonally projected onto the ground and the two planes are substantially perpendicular. You may do it.

15A, the direction connecting two measurement points (reflection markers 116a and 116b) (that is, the direction parallel to the face surface 20a of the golf club 18 and parallel to the ground). direction is called face direction) in the state just before the angle alpha ₁ between the first passing reference line 117s was kept a certain magnitude, for striking a golf ball, the face direction and the second pass criteria angle alpha ₂ of the line 119s is relatively small. On the other hand, in the golf swing shown in FIG. 15B, the angle formed by the face surface direction and the second passage reference line 119s is maintained at a relatively large angle immediately before hitting the golf ball. As described above, the angle α (α ₁ and α ₂ ) between the face surface direction and the passage reference line (the first passage reference line 117 s and the second passage reference line 119 s), and the aspect of the change in the angle are defined as golf swing. Every one is different. When FIG. 15 (a) is compared with FIG. 15 (b), it can be said that the golf swing shown in FIG. 15 (b) is a golf swing having a larger degree of opening of the face surface. It can be said that the angle α (α ₁ and α ₂ ) formed by the face surface direction and the passage reference line, and the manner of change of this angle, well represent the degree of opening of the face surface in the golf swing. The degree of opening of the face surface affects the angle of the face surface of the golf club head at the time of impact, and can be said to characterize the golf swing. The unit 110 obtains and outputs such angles α (α ₁ and α ₂ ) between the face surface direction and the passage reference line.

  In the present embodiment, the first passage reference line 117s is a direction opposite to the golf ball hitting direction by the golf club from the setting position of the golf ball set on the projection views shown in FIGS. 15 (a) and 15 (b). For example, it is an imaginary line passing through a position separated by 125 mm. Further, the second passage reference line 119s is a virtual line that passes through a position separated by, for example, 75 mm from the installation position in a direction opposite to the hitting direction. Both the first passage reference line 117s and the second passage reference line 119s are set within the impact range.

  FIG. 16 is a schematic diagram showing the unit 110. The unit 110 includes a light source 148, a line sensor 150, a half mirror 152, a mirror 154, a data processing unit 156, and a memory 158 in a housing 146 having a transparent window 142 and a display 144. The unit 110 is connected to the computer 120, and can transmit information detected and derived by the unit 110 to the computer 120 or information stored in the memory 158 from the computer 120. It has become. The unit 110 calculates the speeds of the markers 116a and 116b using information on measured timings described later and various kinds of information stored in advance in the memory, and obtains the toe side speed St and the heel side speed Sh. . Further, the rolling ratio R is calculated using the head speed H.

  The light source 148 of the unit 110 is, for example, a light emitting diode (LED) and emits projection light spreading in a conical shape. The projection light emitted from the light source 148 is divided by the half mirror 152, and the projection light component transmitted through the half mirror 152 is transmitted through the transparent window 142 and includes the first measurement target region 117 as the first projection light 112. Irradiate the space. The projection light component reflected by the half mirror 152 is reflected by the mirror 154, passes through the transparent window 142, and is irradiated as a second projection light 114 to a space including the second measurement target region 119. The first measurement target region 117 is a predetermined spatial range with a line corresponding to the first passage reference line 117s on the projection plane as a center line. The second measurement target region 119 is a predetermined spatial range with a line corresponding to the second passage reference line 119s on the projection plane as a center line. The light source in the present invention can be any light source such as a halogen lamp or a laser diode as long as it is a light emitter that irradiates the first measurement target region 117 and the second measurement target region 119 with sufficient luminance. do it.

  In the impact state of the golf swing, each of the reflection markers 116 a and 116 b of the golf club head 12 passes through the second measurement target region 119 after passing through the first measurement target region 117. Each of the reflection markers 116 a and 116 b of the golf club head 12 receives the first projection light 112 when passing through the first measurement target region 117, and this first projection light 112 is converted into an optical path of the first projection light 112. Reflects toward the opposite path. The reflected light 136 (the reflected light from the reflective marker 116a and the reflected light from the reflective marker 116b) of the first projection light 112 reflected in the first measurement target region 117 passes through the transparent window 142 and is a half mirror. The light is reflected at 152 and enters the line sensor 150. Each of the reflection markers 116 a and 116 b of the golf club head 12 receives the second projection light 114 when passing through the second measurement target region 119 and reflects it toward the reverse path of the second projection light 114. To do. The reflected light 138 of the second projection light 114 (the reflected light from the reflective marker 116a and the reflected light from the reflective marker 116b) reflected by the second measurement target region 119 passes through the transparent window 142 and is reflected by the mirror 154. And is incident on the line sensor 150.

FIGS. 17A and 17B are diagrams illustrating the reflective markers 116a and 116b, and FIGS. 17A and 17B are schematic side cross-sectional views of reflective markers having different forms. . The reflective markers 116a and 116b shown in FIG. 17A include a prism layer 161 having a shape in which substantially regular tetrahedral prism block portions 161b are arranged on the surface facing the flat bottom surface 161a, and the prism. It consists of a backing layer 163 arranged to face the prism block portion 161b of the layer 161. The gap between the prism layer 161 and the backing layer 163 is an air layer 162. In the retroreflecting reflector shown in FIG. 17A, the light L incident at an incident angle θ _i from the planar bottom surface 161a is refracted at the bottom surface 161a and reflected at the interface between the prism block portion 161b and the air layer 162. Therefore, it has a function of being reflected from the bottom surface 161a at a reflection angle θ. That is, the incident light is reflected, and reflected light returns through the reverse optical path of the incident light. The reflective markers 116a and 116b shown in FIG. 17 (b) are retroreflective reflectors having a binder layer 162, a reflective layer 164, a surface film layer 166, and a glass bead layer 168 composed of a plurality of glass bead rows. is there. In such a retroreflective reflector, the light L incident at the incident angle θ _i is incident from the surface film layer 166 by refraction and reflection in the surface film layer 166, the glass bead layer 168, and the reflective layer 164. It has a function of being reflected at a reflection angle θ that is the same angle as θ _i . The retroreflective reflector reflects incident light to be reflected light that passes back through the reverse optical path of the incident light.

Such a retroreflective reflector is configured, for example, as shown in FIGS. 17 (a) and 17 (b) so that an adhesive 170 is applied to the back surface for easy pasting. As retroreflective reflectors, various shapes such as those formed into sheets and tapes are commercially available, so retroreflective reflections formed into these commercially available sheets and tapes The body is cut to a required size, and is used with an adhesive 170 attached at an interval D of at least 10 mm on the intersection line E of the golf club head 12.
In the present invention, the retroreflective reflector is not particularly limited. For example, the retroreflector may have a form shown in FIG. 17A or a form shown in FIG. For example, a microprism retroreflector such as that shown in FIG. 17B is preferable when it is desired to reflect the irradiated light amount at as much a ratio as possible.

  In the line sensor 150, n photosensors 151a, 151b,... 151n are arranged in a line in one direction. As shown in FIG. 18, the light receiving surface of the line sensor 150 is configured by arranging the light receiving surfaces of the photosensors 151a, 151b,... 151n in one direction. The line sensor 150 sequentially outputs (scans) the electrical signals corresponding to the reflected light incident on the light receiving surface of each photosensor output from each photosensor 151 in time series. The line sensor 150 is connected to the data processing unit 156, and the data processing unit 156 acquires time-series electrical signals output from the photosensors arranged in a line in one direction. The first measurement target region 117 and the second measurement target region 119 have a shape corresponding to the light receiving surface of the line sensor 150 and are determined according to the arrangement position and the arrangement angle of the unit 110. In other words, corresponding to the light receiving surface of the line sensor 150, the first measurement target region 117 and the second measurement target region 119, and thus the first passage reference line 117s and the second passage reference line on the projection surface. 119s is fixed.

  The unit 110 is arranged with its direction and position adjusted so that the line sensor 150 can receive light (reflected light) coming from the line-shaped measurement target region. The unit 110 is a measurement target region of the reflective markers 116 a and 116 b of the golf club 10 that passes through the linear measurement target region (first measurement target region 117 and second measurement target region 119) determined by the line sensor 150. The passage timing and the passage timing of the passage reference lines (the first passage reference line 117s and the second passage reference line 119s) that are the center lines of the respective measurement target regions are detected.

  Since the present invention uses such a line sensor, when detecting a golf club that passes through a limited line-shaped space (measurement target region), the projection light is limited to the line-shaped measurement target region. There is no need to irradiate. According to the present invention, it is possible to detect a moving object passing through a spatially limited line-shaped measurement target area without using a large and expensive apparatus such as a laser beam irradiation means for irradiating a limited spatial range. can do.

In the present embodiment, as shown in FIG. 15, the timing at which the reflective marker 116a passes the first passage reference line 117s in the golf swing is Ta _(P1) , and the reflection marker 116a passes the second passage reference line 119s. The timing is Ta _(P2) , the timing when the reflective marker 116b passes the first passage reference line 117s is Tb _(P1) , and the timing when the reflective marker 116b passes the second passage reference line 119s is Tb _(P2) . To do.

FIGS. 19A and 19B are schematic diagrams for explaining an example of detection of the passage timing of the measurement areas of the reflection markers 116 a and 116 b by the line sensor 150.
FIG. 19A is a schematic side view showing an example of the state of passage of the golf club head 12 in the first measurement target region 117 and the second measurement target region 119 in the impact state of the golf swing. 19 (b) is a graph of time-series electrical signals output from the line sensor 150 and acquired by the data processing means 156 in the impact state shown in FIG. 19 (a).
In the graph of FIG. 19B, the vertical axis indicates the amount of reflected light corresponding to the electrical signal. When the golf club head 12 passes through the first measurement target region 117, each of the photosensors 151a to 151n constituting the line sensor 150 divides the first measurement target region 117 into n divided regions 117a, respectively. The light (reflected light) coming from 117b, 117c,. Similarly, when the golf club head 12 passes through the second measurement target region 119, each of the photosensors 151a to 151n constituting the line sensor 150 divides the second measurement target region 119 into n different divisions. The light (reflected light) coming from the regions 119a, 119b, 119c,.

In this case, the line sensor 150, the amount of light each of a plurality of photosensors has received, by scanning from top to bottom (first measurement area 117 and the second measurement area 119 from top scan time t _A The data processing means 156 receives a time-series electrical signal output corresponding to a change in the time-series light amount received by each sensor, and the light amount incident on the line sensor 150 has a peak value. Detect timing. In the example shown in FIG. 19A, when the golf club head 12 passes through the first measurement target region 117, the golf club head 12 moves while being inclined with respect to the first measurement target region 117, and the reflection markers 116a and 116b are the first. The measurement object region 117 is sequentially passed. When passing through the first measurement target region 117 and passing through the second measurement target region 119, the face surface direction of the golf club head 12 is substantially the extension direction of the second measurement target region 119. The reflection markers 116a and 116b pass through the second measurement target region 119 almost at the same time.

The scanning by the line sensor 150 is performed from the upper side to the lower side in the figure, and the reflection marker 116a provided on the heel side has a scanning time t _A as shown in the graph of FIG. 19B. is detected at a relatively early timing (early time), reflective markers 116b will always be detected by the relatively late timing of the scan time t _a (second half time). Has been such a signal data processing means 156 which has received the (more specifically, the timing information acquisition unit 182 to be described later) output from the line sensor 150 checks, at scan time t _A, the position of the peak of the light quantity (the electric signal) By doing so, it is possible to distinguish between the reflected light from the reflective marker 116a and the reflected light from the reflective marker 116b. By checking the peak position of the light amount (electric signal) at the scan time t _A for each measurement target region, the timing at which each reflection marker passes through each passage reference line can be detected.

When the time required to scan the entire plurality of photosensors for the line sensor 150 is remarkably shortened, each reflective marker is positioned at the center of each measurement target region, that is, the first passage reference line 117s as described below. The timing of passing through the second passage reference line 119s may be derived.
FIGS. 20A and 20B are diagrams illustrating another example of detection of the passage timing of each reflection marker 16 (reflection markers 116 a and 116 b) through the measurement target region by the line sensor 150.
FIG. 20A is a schematic side view showing another example of the state of passage of the golf club head 12 in the first measurement target region 117 and the second measurement target region 119 in a golf swing impact state. 20B is a graph of time-series output values output from the line sensor 150 and acquired by the data processing unit 156 in the impact state shown in FIG.

In this case, the line sensor 150 detects whether or not the reflected light is received at each scanning time t _B (see FIG. 20B) for each of the photosensors 151a, 151b,. A digital signal indicating whether or not light is received is output. Then, for each scan time t _B, of the photo sensor detects the light, the output value corresponding to the position of the line sensor 150 is output. The data processing unit 156 detects the timing at which each reflection marker passes through each passage reference line based on such an output value. In the above example, reflective markers 116a and reflective markers 116b is, while the scanning time t _A has elapsed, it shows the case where get through each measurement area. In the second example, this scan time t _B (for example, 51.2 (μs)) is significantly shorter than the scan time t _A , and at the scan time t _B , the reflection marker 116a and the reflection marker 116b Do not pass through the area.

At every scan time t _B (for example, 51.2 μs), a digital signal that indicates that light has been detected is output from the photo sensor that has received the reflected light from the measurement target region among the plurality of photo sensors of the line sensor 150. Is done. In the line sensor 150, when the reflected light is detected by each of the m photosensors in the upper part among the plurality of photosensors of the line sensor 150, that is, the light (reflected light) coming from any of the divided regions 117 a to 117 m. ) Is received, the output value “2” is output. Further, when the reflected light is detected by nm photosensors in the lower part among the plurality of photosensors of the line sensor 150, that is, light (reflected light) coming from any one of the divided regions 117m + 1 to 117n. Is received, the output value “1” is output. These divided regions 117a to 117m are upper regions in the drawing of the divided regions, and this region is set so that only the reflective marker 116a on the heel side among the reflective markers 116a and 116b passes. The divided areas 117m + 1 to 117n are lower areas in the figure of the divided areas, and this area is set so that only the reflective marker 116b on the toe side out of the reflective markers 116a and 116b passes.

  In the example shown in FIG. 20A, when the golf club head 12 passes through the first measurement target region 117, the golf club head 12 moves with the face surface 20a inclined with respect to the first measurement target region 117, and the reflection marker 116a. , 116b sequentially pass through the first measurement target region 117. Then, when passing through the first measurement target region 117 and passing through the second measurement target region 119, the angle formed between the face surface 20a and the extending direction of the second measurement target region 119 is reduced (small). ) In this state, the reflection markers 116a and 116b are passing through the second measurement target region 119 temporarily at the same time.

In the example shown in FIG. 20B, the reflection marker 116a passes through the first measurement target region 117, but only the scan time t _B × 9 (the number in which the output value “2” is continuously output). It takes time. Reflective markers 116a the timing _{T a} which passes through the center line (i.e. the first pass reference line 117s) of the first measurement target region 117 _(P1), the timing _{T b (P1} of reflective markers 116b passes through the first passage reference line 117s ₎ Are as shown in FIG.

Further, the reflection markers 116a and 116b temporarily pass through the second measurement target region 119 at the same time. The output value is “3” (output value “2” + “1”) while passing simultaneously at the same time. It takes a scan time t _B × 11 (the number of output values “2” and “3” being output continuously) for the reflection marker 116 a to pass through the second measurement target region 119. Reflective markers 116a center line of the second measurement target region 119 (i.e. the second pass reference line 119s) timing _{T a} passing _(P2), the timing _{T b} of reflective markers 116b passes through the second second pass reference line 119s _(P2) is as shown in FIG. 20 (b). When the time required to scan the entire plurality of photosensors is remarkably shortened, each timing can be derived in this manner based on the output value output from the line sensor 150.

  FIG. 21 is a block diagram showing the configuration of the data processing means 156. As shown in FIG. Hereinafter, the data processing means 156 will be described with reference to FIG. 21 and FIGS. 15 (a) and 15 (b). The data processing means 156 includes a timing information acquisition unit 182, a reference position passage timing difference deriving unit 184, a reference position movement required time deriving unit 186, a golf club head moving speed deriving unit 188, a horizontal delay distance deriving unit 190, and a face surface. An angle deriving unit 192 is provided. The timing information acquisition unit 182 of the data processing unit 156 receives a signal output from the line sensor 150, and passes through the first passage reference line 117s of the first measurement target region 117 for each of the reflection markers 116a and 116b. For each. Similarly, for each of the reflection markers 116a and 116b, the timing of passing through the second passage reference line 119s of the second measurement target region 119 is obtained.

Then, the timing difference deriving unit 184, a timing _{T a} which reflective markers 116a passes through the first passage reference line 117s _(P1), and the timing _{T b} of reflective markers 116b passes through the first passage reference line 117s _(P1) The timing difference _Td1 is obtained. Similarly, reflecting the marker 116a is a timing _{T a} which passes through the second passage reference line 119s _(P2), and the timing _{T b} of reflective markers 116b passes through the second passage reference line 119s _(P2), timing difference T _{d2 is} also obtained and stored in the memory.

Reference position between travel time derivation unit 186 includes a timing _{T a} which reflective markers 116a passes through the first passage reference line 117s _(P1), reflective markers 116a the timing _{T a} which passes through the second passage reference line 119s _{(P2 )} And a timing difference _Tpa . Similarly, it reflected the marker 116b is a timing _{T b} passing through the first passage reference line 117s _(P1), and the timing _{T b} of reflective markers 116b passes through the second passage reference line 119s _(P2), timing difference T _{pb is} also obtained and stored in the memory 158.

The golf club head moving speed deriving unit 188 uses these T _pa and T _pb and the distance W between the first passage reference line 117s and the second passage reference line 119s to determine the heel side of the golf club head 12 in the impact state. The moving speed between the first passing reference line 117s and the second passing reference line 119s at the measurement position 116a and the measurement position 116 is obtained from the speed Sh and the toe side speed St.
The memory 158 stores a distance W between the first passage reference line 117s and the second passage reference line 119s. The golf club head moving speed deriving unit 188 uses the timing difference T _pa and timing difference T _pb derived by the reference position movement required time deriving unit 186 and the distance W, and the reflection marker 116 a provided on the golf club head 12. The movement speed in the impact state, that is, the heel side speed Sh (= D / T _pa ), or the movement speed in the impact state of the reflective marker 116b, that is, the toe side speed St (= D / T _pb ) is obtained. This distance W is a distance between the first passage reference line 117s and the second passage reference line 119s in a direction perpendicular to both the first passage reference line 117s and the second passage reference line 119s.
The golf club head moving speed deriving unit 188 stores the heel side speed Sh and the toe side speed St of the golf club head 12 derived in this manner in the memory 158.

  As the head speed H, for example, the moving speed of the predetermined position in the golf club head 12 is detected by speed detecting means (not shown) that can detect the moving speed of the predetermined position in the golf club head 12, and the movement of the predetermined position is detected. The speed is the head speed H of the golf club head. The place where the head speed H is measured is preferably a place that is not easily affected by the rotation of the golf club head 12, for example, a region opposite to the face portion of the crown portion.

Further, in the computer 120, the evaluation value α ₁ and the evaluation value α ₂ received from the unit 110, the distance W between the first passage reference line 117s and the second passage reference line 119s, the distance D between the measurement positions 116a and 116b, and the like. Based on this information, a diagram representing the behavior of the golf club head in the impact state may be created and displayed on the display 124. FIGS. 22 (a) and 22 (b) show examples of such diagrams generated by the computer 120 and displayed on the display 124. The golf club heads in the impact state in different golf swings. Represents the behavior of each. By displaying such a diagram, the operator and the golfer 34 themselves can change the behavior of the golf club head in the impact state (the angle between the golf club shaft and the passing reference line when passing through each passing reference line, In addition, it is possible to intuitively grasp the manner in which the angle is changed while passing between the passage reference lines.

FIG. 23 is a flowchart showing a method for measuring the speed of the golf club head in the swing evaluation method of the present invention.
First, the golfer 34 grips the golf club 10 including the golf club head 12 provided with the reflective marker 116a and the reflective marker 116b, and performs golf swing (step S102). In this case, in the apparatus 100, for the golf swing performed by the golfer 34, using the unit 110, the first passage reference line 117s and the position corresponding to the reflective marker 116a and the reflective marker 116b provided on the golf club head 12 are used. The passage timing of the second passage reference line 119s is obtained.

  Specifically, the timing information acquisition unit 182 receives a signal output from the line sensor 150, and determines the timing at which each of the reflection markers 116a and 116b passes through the first passage reference line 117s of the first measurement target region 117. Ask for each. Similarly, for each of the reflection markers 116a and 116b, the timing of passing through the second passage reference line 119s of the second measurement target region 119 is obtained (step S104).

Then, the timing difference deriving unit 184, a timing _{T a} which reflective markers 116a passes through the first passage reference line 117s _(P1), and the timing _{T b} of reflective markers 116b passes through the first passage reference line 117s _(P1) The timing difference _Td1 is obtained. Similarly, reflecting the marker 116a is a timing _{T a} which passes through the second passage reference line 119s _(P2), and the timing _{T b} of reflective markers 116b passes through the second passage reference line 119s _(P2), timing difference T _{d2 is} also obtained and stored in the memory (step S106).

At the same time, the movement time deriving unit 186 between the reference positions causes the timing Tb _(P1) when the reflection marker 116a passes the first passage reference line 117s and the timing T when the reflection marker 116a passes the second passage reference line 119s. A timing difference _Tpa with _{a (P2)} is obtained. Similarly, it reflected the marker 116b is a timing _{T b} passing through the first passage reference line 117s _(P1), and the timing _{T b} of reflective markers 116b passes through the second passage reference line 119s _(P2), timing difference T _{pb is} also obtained and stored in the memory (step S108).

The golf club head moving speed deriving unit 188 uses the T _pa and T _pb and the distance W in the horizontal direction from the ground between the first passage reference line 117s and the second passage reference line 119s. The toe side speed St and the heel side speed Sh of the golf club head 12 are obtained. At this time, the head speed H of the golf club head 12 is measured by another speed detection means.
The memory 158 stores a distance W between the first passage reference line 117s and the second passage reference line 119s. The golf club head moving speed deriving unit 188 uses the timing difference T _pa and timing difference T _pb derived by the reference position movement required time deriving unit 186 and the distance W, and the reflection marker 116 a provided on the golf club head 12. The movement speed in the impact state, that is, the toe side speed St (= D / T ₁ ), and the movement speed in the impact state of the reflective marker 116b, that is, the heel side speed Sh (= D / T ₂ ) are obtained ( Step S110).
The moving speed deriving unit 188 stores the toe side speed St, the heel side speed Sh, and the head speed H derived in this manner in the memory 158.
Then, the rolling ratio R is calculated from the toe side speed St, the heel side speed Sh, and the head speed H.

  In the embodiment, the swing measurement / data processing unit 110 is provided with data processing means 156 that receives digital information representing timing and calculates an evaluation value. In the golf swing evaluation apparatus of the present invention, such data processing means may be provided in a computer connected to the swing measurement / data processing unit. That is, a configuration may be adopted in which the swing measurement / data processing unit acquires and outputs only digital information indicating timing, and the computer (CPU) that acquires this information executes the software.

Also in the present embodiment, for example, the measuring device 100 is used to measure the head speed H, the toe side speed St, and the heel side speed Sh of the golf club head 12 when the golf club 10 swings, and further rolling. The ratio R is calculated. As a result, the swing of the golfer 34 can be classified because the magnitude of the amount by which the golf club head 12 is rotated about the shaft axis S as the rotation axis is known.
Further, since the measuring apparatus 100 also measures the head speed H, the golfer's swing can be classified based on the head speed H and the rolling ratio.
Furthermore, the rotation of the golf club head 12 around the shaft axis S is also affected by the rigidity and torque of the golf club shaft 14. For this reason, the rigidity and torque of the golf club shaft 14 can also be evaluated. Thereby, a golf club shaft can also be selected according to a golfer's swing. Thus, a golf club shaft having an appropriate specification (specification) can be selected for each classified swing, and the appropriateness of the rigidity and torque of the golf club shaft can be determined for each swing.
Further, the golf club head has a different (or different) rotational moment about the shaft axis S depending on the position of the center of gravity. However, by calculating the rolling ratio R, evaluating the swing, classifying the swing, etc., it is possible to select a golf club head having an appropriate specification (specification) for each classified swing. Thus, the appropriateness of the golf club head (the center of gravity position of the golf club head) can be determined for each swing.

  In any of the above-described embodiments, the head speed H for calculating the rolling ratio R (ratio represented by δ / H) is obtained by measuring the speeds of two markers (the speed of two points). May be measured by other different measuring means. Furthermore, the average speed of the speeds of two markers (the speed of two points) may be set as the head speed H.

The present invention is basically as described above. The swing evaluation method of the present invention has been described in detail above. However, the present invention is not limited to the above embodiment, and various improvements or modifications may be made without departing from the spirit of the present invention. It is.
In the present invention, it is possible to measure the head speed H, the toe side speed St, and the heel side speed Sh of the golf club head 12 during the swing of the golf club 10 and further calculate the rolling ratio R. The configuration of the measuring device is not particularly limited.

It is a schematic diagram which shows the golf club utilized for the evaluation method of the swing of this invention. (A) is a typical perspective view which shows the golf club head of the golf club utilized for the swing evaluation method of this invention, (b) is a typical side surface of the golf club head shown to Fig.2 (a). FIG. In (a), the vertical axis represents the difference between the heel side speed and the toe side speed, and the horizontal axis represents the tester, and the influence of the distance _{GL on} the difference between the heel side speed and the toe side speed. (B) is a ratio between the heel side speed and the toe side speed on the vertical axis and the tester on the horizontal axis, and the ratio between the heel side speed and the toe side speed. Is a graph showing the influence of the distance _{GL on} the vertical axis, and the vertical axis represents the ratio between the head speed and the difference between the heel side speed and the toe side speed, and the horizontal axis represents the tester. It is a graph which shows the influence of distance _GL with respect to this ratio. It is a graph showing the correlation between the rolling ratio and the head speed, with the vertical axis representing the rolling ratio (ratio) and the horizontal axis representing the head speed. It is a graph which shows the correlation between a rolling ratio and a wrist turn ratio, with a rolling ratio (ratio) on the vertical axis and a wrist turn ratio on the horizontal axis. It is a graph showing the correlation between the head speed difference and the head speed with the vertical axis representing the head speed difference and the horizontal axis representing the head speed. It is a graph showing the correlation between the head speed difference and the wrist turn ratio, with the head speed difference on the vertical axis and the wrist turn ratio on the horizontal axis. It is a graph showing the correlation between the head speed difference and the rolling ratio, with the head speed difference on the vertical axis and the rolling ratio (ratio) on the horizontal axis. (A) is a block diagram which shows the outline | summary of an example of the golf club head behavior measuring apparatus of this invention, (b) shows the processing structure of the computer of the golf club head behavior measuring apparatus shown to (a). It is a block diagram. It is a figure which shows an example of the time history of the movement of a marker obtained in the measuring apparatus of this invention. (A)-(e) is a schematic diagram which shows an example of the marker and marker feature point in this invention. (A)-(d) is a schematic diagram which shows the other example of the marker in this invention, and a marker feature point. It is a schematic diagram which shows the measuring device which measures the speed of the golf club head used for the swing evaluation method of this invention. It is a schematic diagram which expands and shows the golf club head used for the swing evaluation method of this invention. (A) And (b) is a schematic diagram for demonstrating the behavior of the golf club head in the impact state of a golf swing, respectively. It is a schematic diagram which shows the structure of the swing measurement and data processing unit of the measuring device shown in FIG. (A), (b) is typical sectional drawing which shows the reflective marker installed in a golf club head used with the golf swing evaluation method of this invention. It is a schematic diagram which shows the line sensor of the swing measurement and data processing unit shown in FIG. FIG. 17 shows an example of detection of a golf club head passage timing in the swing measurement / data processing unit shown in FIG. 16, wherein (a) shows a first measurement target region and a second measurement in a golf swing impact state. It is a typical side view which shows an example of the state of passage of the golf club head in an object field, and (b) is a graph of the time series electric signal outputted from a line sensor in the impact state shown in (a). . FIG. 17 shows another example of detection of the passing timing of the golf club head in the swing measurement / data processing unit shown in FIG. 16, wherein (a) shows a first measurement target region and a first measurement target in a golf swing impact state. 2 is a schematic side view showing another example of the state of passage of the golf club head in the measurement target region, and (b) is a schematic diagram showing an output value output from the line sensor in the impact state shown in (a). FIG. FIG. It is a block diagram which shows the structure of the data processing means of the swing measurement and data processing unit shown in FIG. (A) And (b) is a schematic diagram which shows the behavior of the golf club head in an impact state respectively displayed on the display of the measuring device shown in FIG. It is a flowchart which shows the measuring method of the speed of the golf club head in the swing evaluation method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Golf club 12 Golf club head 14 Golf club shaft 16 Grip 20 Face part 20a Face surface 22 Sole part 24 Crown part 26 Side part 30a, 30b, Marker 30c Marker 34 Golfer 40 Measuring device 42, 44 Camera 46, 48 Illumination light source 50 Control device 52, 120 computer 54 Signal processing unit 56 Image processing unit 58 Analysis unit 60 Output unit 66 Monitor 68 Operation system 100 Measuring device 116a, 116b Reflective marker 117s First passage reference line 119s Second passage reference line 142 Transparent window 144 Display 146 Housing 146
148 Light source 150 Line sensor 152 Half mirror 154 Mirror 156 Data processing means 158 Memory 182 Timing information acquisition unit 184 Reference position passage timing difference deriving unit 186 Reference position moving time deriving unit 188 Golf club head moving speed deriving unit 190 Horizontal delay distance Deriving unit 192 Face surface angle deriving unit E Intersecting line _GL distance

Claims (1)

A method for evaluating a swing of a golf club having a golf club head provided with a hosel portion to which a golf club shaft is mounted on a crown portion,
In a state where the golf club head is installed on a horizontal plane, the golf club head includes an axis of the golf club shaft and is separated by at least 10 mm on an intersection line where the plane perpendicular to the horizontal plane and the crown portion of the golf club head intersect For two points with known intervals , the golf club swing speed is measured, and the swing is evaluated based on the speed of each point .
The swing evaluation method is characterized in that a ratio represented by δ / H is used for the swing evaluation , where H is the head speed during the swing and δ is the difference in speed between the points .

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