JP2021058303A - Fitting device of golf club - Google Patents

Abstract

To provide a fitting device that enables a golf club with a balance suitable for a golfer to be selected.SOLUTION: A fitting device includes: an acquisition part for acquiring measurement data obtained by measuring a swing action of a test club by a golfer with a measuring device; a calculation part for calculating one or a plurality of first indexes showing an amount of change in an opening degree of a face surface of a head included in the test club in the swing action on the basis of the measurement data; and a selection part for selecting a balance of a golf club suitable for the golfer on the basis of the one or the plurality of first indexes.SELECTED DRAWING: Figure 4

Description

The present invention relates to fitting devices, methods and programs for selecting a golf club suitable for a golfer.

Conventionally, various fitting methods have been proposed in which a golfer is made to test-hit a test club, the operation is measured by a measuring device, and a golf club suitable for the golfer is selected based on the measurement data at this time. Patent Document 1 describes a fitting method that calculates indexes such as the weight of a golf club suitable for a golfer, moment of inertia, and rigidity of a shaft based on measurement data, and recommends a golf club that matches these indexes to the golfer. Is disclosed. According to the fitting method as described above, it is possible to provide a golf club with specifications suitable for each individual, and improvement of shots such as an increase in flight distance and a reduction in left-right blur is expected.

JP-A-2017-170105

By the way, one of the specifications of golf clubs is an item called "balance". This is also called a swing weight, and is an index showing the weight feeling of the head when swinging a golf club, and affects the swing comfort. In general, balance is represented by a combination of the alphabets A to E and the numbers 0-9, such as "D0", meaning that the numbers A to E are heavier, and the numbers are The larger it is, the heavier it is. A "heavy" balance can mean that the center of gravity of the golf club is closer to the head side, making it easier to feel the resistance of the head when swinging the golf club, and thus making it more difficult to swing. On the contrary, "light" balance can mean that the center of gravity of the golf club is closer to the grip side, the resistance of the head is less likely to be felt when swinging the golf club, and therefore it is easier to swing.

Regarding the above balance, some golfers are more suitable for lighter weights, while others are more suitable for heavier ones. Therefore, if it is possible to provide a golf club with a balance suitable for each individual, further improvement in shots is expected. However, until now, a method for identifying a balance suitable for a golfer has not been proposed, and in this respect, it has not always been possible to select a golf club that is truly suitable for a golfer.

It is an object of the present invention to provide a fitting device, method and program that enables a golfer to select a golf club with a suitable balance.

The fitting device according to the first aspect includes an acquisition unit that acquires measurement data obtained by measuring the swing motion of a test club by a golfer with a measuring device, and a head included in the test club during the swing motion based on the measurement data. A calculation unit that calculates one or more first indexes representing the amount of change in the degree of opening of the face surface of the golf club, and a selection that selects a balance of golf clubs suitable for the golfer according to the one or more first indexes. It has a part.

The fitting device according to the second aspect is the fitting device according to the first aspect, and the calculation unit is based on the angular velocity data around the axis substantially parallel to the shaft of the test club included in the measurement data. The first index is calculated.

The fitting device according to the third viewpoint is a fitting device according to the first viewpoint or the second viewpoint, and the calculation unit is included in the measurement data around an axis substantially parallel to the toe-heel direction of the test club. The first index is calculated based on the angular velocity data of.

The fitting device according to the fourth aspect is the fitting device according to the second or third aspect, and the angular velocity data is measured by an angular velocity sensor attached to the test club included in the measuring device. It is data.

The fitting device according to the fifth aspect is the fitting device according to any one of the first to fourth viewpoints, and the calculation unit refers to the one or a plurality of first indexes based on the measurement data. Calculate one or more preliminary indicators representing different characteristics of the swing motion. The selection unit selects the balance according to the one or a plurality of preliminary indexes in addition to the one or a plurality of first indexes.

The fitting device according to the sixth aspect is the fitting device according to the fifth aspect, and the calculation unit uses the one or a plurality of preliminary indexes as an index indicating the power output by the golfer's arm during the swing operation. , At least an index indicating the power input to the test club during the swing operation, an index indicating the energy exerted by the golfer during the swing operation, and an index indicating the torque exerted by the golfer during the swing operation. One is included.

The fitting device according to the seventh aspect is a fitting device according to any one of the first to sixth aspects, and the calculation unit is different from the one or a plurality of first indexes based on the measurement data. , One or a plurality of second indexes representing the characteristics of the swing motion are calculated. The selection unit selects the rigidity of the shaft suitable for the golfer according to the one or a plurality of second indexes.

The fitting program according to the eighth aspect causes the computer to execute the following.
-Acquiring measurement data obtained by measuring the swing motion of the test club by a golfer with a measuring device-Based on the measurement data, the amount of change in the degree of opening of the face surface of the head included in the test club during the swing motion is determined. Calculate one or more first indicators to represent-Select a golf club balance suitable for the golfer according to the one or more first indicators.

The fitting method according to the ninth aspect includes the following.
-Acquiring measurement data that measures the swing motion of the test club by the golfer using a measuring device-Using a computer, based on the measurement data, the face of the head included in the test club during the swing motion Calculating one or more first indicators representing the amount of change in the degree of surface opening-Recommending to the golfer the balance of golf clubs suitable for the golfer, which is determined according to the one or more first indicators.

According to the findings obtained by the present inventors, the amount of change in the degree of opening of the face surface of the head included in the golf club during the swing operation by the golfer affects the balance of the golf club suitable for the golfer. In this respect, according to the above viewpoint, the balance of the golf club suitable for the golfer is selected according to the amount of change in the degree of opening of the face surface. Therefore, it becomes possible to select a golf club with a balance suitable for the golfer.

The figure which shows the fitting system which includes the fitting apparatus which concerns on 1st Embodiment. The functional block diagram of the fitting system which concerns on 1st Embodiment. The figure explaining the International Flex Code (IFC). The flowchart which shows the flow of the fitting process which concerns on 1st Embodiment. The figure explaining the bending of the shaft during a swing. The figure explaining the index which shows the change amount of the opening degree of the face surface of the head which concerns on 1st Embodiment. The figure explaining another index showing the amount of change of the opening degree of the face surface of the head which concerns on 1st Embodiment. A graph summarizing the relationship between two indexes showing the amount of change in the degree of opening of the face surface of the head according to the first embodiment and the optimum balance when a large number of golfers actually hit a golf club. The flowchart which shows the flow of the fitting process which concerns on 2nd Embodiment. The figure explaining the model for calculating the preliminary index. A graph summarizing the relationship between the index and arm output power representing the amount of change in the degree of opening of the face surface of the head according to the second embodiment when a large number of golfers actually hit a golf club, and the optimum balance. The figure which shows the fitting system which includes the fitting apparatus which concerns on 3rd Embodiment. The functional block diagram of the fitting system which concerns on 3rd Embodiment. The figure explaining the index which shows the change amount of the opening degree of the face surface of the head which concerns on 3rd Embodiment. A table summarizing the relationship between an index showing the amount of change in the degree of opening of the face surface of the head according to the third embodiment and the optimum balance when a large number of golfers actually hit a golf club.

Hereinafter, a golf club fitting device, a method, and a program according to some embodiments of the present invention will be described with reference to the drawings.

<1. First Embodiment>
<1-1. Outline configuration of fitting system>
1 and 2 show the overall configuration of the fitting system 100 including the fitting device 2 according to the present embodiment. The fitting device 2 assists the golfer G in selecting a golf club suitable for the golfer G based on the measurement data obtained by measuring the swing of the test golf club (hereinafter referred to as the test club) 4. It is a device of. The test club 4 is a general golf club, and includes a shaft 40, a head 41 provided at one end of the shaft 40, and a grip 42 provided at the other end of the shaft 40. In the present embodiment, the measuring device that measures the swing motion is the inertial sensor unit 1. The fitting device 2 constitutes a fitting system 100 together with the inertial sensor unit 1.

Hereinafter, the configuration of the inertial sensor unit 1 and the fitting device 2 will be described, and then the flow of the fitting process will be described.

<1-2. Composition of each part>
<1-2-1. Inertia sensor unit configuration>
As shown in FIG. 1, the inertial sensor unit 1 is attached to the end of the grip 42 of the test club 4 opposite to the head 41, and measures the behavior of the grip 42. The inertial sensor unit 1 is compact and lightweight so as not to interfere with the swing operation. The inertial sensor unit 1 can be detachably configured with respect to the test club 4.

As shown in FIG. 2, the inertial sensor unit 1 is equipped with an acceleration sensor 11, an angular velocity sensor 12, and a geomagnetic sensor 13. Further, the inertial sensor unit 1 is also equipped with a communication device 10 for transmitting measurement data output from these sensors 11 to 13 to an external fitting device 2. In the present embodiment, the communication device 10 is wireless so as not to interfere with the swing operation, but may be connected to the fitting device 2 by wire via a cable.

The acceleration sensor 11, the angular velocity sensor 12, and the geomagnetic sensor 13 measure acceleration, angular velocity, and geomagnetism in the xyz local coordinate system with the mounting positions of these sensors 11 to 13 as the origin, respectively. More specifically, the acceleration sensor 11 measures _{accelerations a x} , a _y , a _z in the x-axis, y-axis, and z-axis directions. The angular velocity sensor 12 measures _{the angular velocities ω x} , ω _y , and ω _z around the x-axis, y-axis, and z-axis. Geomagnetic sensor 13 measures the x-axis, y-axis and z-axis direction terrestrial magnetism m _x, m _y, a m _z. These measurement data are collected as time-series data in a predetermined sampling cycle Δt and transmitted to the fitting device 2 via the communication device 10. The xyz local coordinate system is a three-axis Cartesian coordinate system, and the z-axis is oriented substantially parallel to the shaft 40. The x-axis is oriented as parallel as possible to the toe-heel direction of the head 41, and the y-axis is oriented as parallel as possible to the normal direction of the face surface of the head 41.

<1-2-2. Fitting device configuration>
The fitting device 2 is a general-purpose computer as hardware, and is realized as, for example, a desktop computer, a notebook computer, a tablet computer, a smartphone, or the like. As shown in FIG. 2, the fitting device 2 is manufactured by installing the fitting program 3 according to the present embodiment on a general-purpose computer. The fitting program 3 is acquired by the fitting device 2 from a recording medium 20 such as a computer-readable CD-ROM, or via a communication network such as a local area network (LAN) or the Internet connected to the communication unit 25. To. The fitting program 3 is software for analyzing the swing motion based on the measurement data transmitted from the inertial sensor unit 1 and outputting information that assists in selecting a golf club suitable for the golfer G. The fitting program 3 causes the fitting device 2 to execute an operation described later.

The fitting device 2 includes a display unit 21, an input unit 22, a storage unit 23, a control unit 24, and a communication unit 25. These units 21 to 25 are connected via a bus line 26 and can communicate with each other. In the present embodiment, the display unit 21 is composed of a liquid crystal display or the like, and displays information described later to the user. The term "user" as used herein is a general term for golfers G themselves, their instructors, golf club salespeople, and other persons who require fitting results. The input unit 22 can be composed of a mouse, a keyboard, a touch panel, and the like, and receives an operation from the user on the fitting device 2. The communication unit 25 is a communication interface that enables communication between the fitting device 2 and the external device, and receives measurement data from the inertial sensor unit 1.

The storage unit 23 is composed of a non-volatile storage device such as a hard disk. In addition to storing the fitting program 3 in the storage unit 23, measurement data transmitted from the inertial sensor unit 1 is stored. Further, the club database (DB) 27, the head database (DB) 28, the shaft database (DB) 29, and the grip database (DB) 30 are stored in the storage unit 23. The club DB 27 contains information indicating various specifications of a large number of golf clubs (total weight, head weight, head volume, shaft weight, shaft length, various shaft rigidity, loft angle, balance, etc.). It is stored in association with information that identifies the type of club. Similarly, information indicating various specifications (weight, volume, loft angle, etc.) of a large number of heads is stored in the head DB 28 in association with information for specifying the type of the head, and a large number of information is stored in the shaft DB 29. Information indicating various specifications of the shaft (weight, length, various rigidity, etc.) is stored in association with information for specifying the type of the shaft, and the grip DB 30 contains various specifications (weight, hardness, etc.) of a large number of grips. Etc.) is stored in association with the information that identifies the type of grip.

The control unit 24 can be composed of a CPU, a ROM, a RAM, and the like. The control unit 24 virtually operates as the acquisition unit 24A, the calculation unit 24B, the selection unit 24C, and the display control unit 24D by reading and executing the fitting program 3 in the storage unit 23. Details of the operation of each part 24A to 24D will be described later.

<1-3. Fitting process>
Subsequently, the fitting process executed by the fitting system 100 will be described. First, the outline of the process will be described. Measurement data obtained by measuring the state of the golfer G when he / she hits the test club 4 is acquired, and based on the measurement data, the specifications of the golf club suitable for the golfer G (hereinafter referred to as “specification”). The optimum specifications) are determined. Then, a golf club that meets the conditions of the optimum specifications is selected as a golf club suitable for the golfer G (hereinafter, may be referred to as an optimum club), and is recommended to the golfer G. This makes it possible to provide the golfer G with an optimum club having optimum specifications that matches the characteristics of the swing operation of the golfer G. As a result, the shot of the golfer G can be improved by increasing the flight distance of the shot and reducing the left-right blur.

In the present embodiment, a balance suitable for the golfer G (hereinafter, may be referred to as an optimum balance) is determined as one item of the optimum specifications. The balance, also called a swing weight, is an index showing the weight feeling of the head when swinging a golf club, and affects the swing comfort. Generally, the balance is represented by a combination of the alphabets A to E and the numbers 0-9, with "A0" being the lightest and "E9" being the heaviest. A "heavy" balance can mean that the center of gravity of the golf club is closer to the head side, making it easier to feel the resistance of the head when swinging the golf club, and thus making it more difficult to swing. On the contrary, "light" balance can mean that the center of gravity of the golf club is closer to the grip side, the resistance of the head is less likely to be felt when swinging the golf club, and therefore it is easier to swing. In the present embodiment, a golf club that matches the characteristics of the swing motion of the golfer G is selected in consideration of the above balance.

Further, in the present embodiment, as another item of the optimum specifications, the rigidity of the shaft suitable for the golfer G (hereinafter, may be referred to as the optimum rigidity) is determined. The rigidity of the shaft referred to in the present embodiment is evaluated as a distribution of flexural rigidity at a plurality of positions of the shaft (hereinafter, may be referred to as an EI distribution). The EI distribution according to the present embodiment is quantitatively expressed using numerical values, and more specifically, expressed using the International Flex Code (IFC). Here, this IFC will be described. IFC is a known index showing the characteristics of a shaft widely proposed by the applicant, and has already been described in detail in various documents including Patent Document 1. Therefore, it is not always necessary to explain it again here, but for reference, a brief explanation will be given here as well.

As shown in FIG. 3, the IFC expresses the flexural rigidity of the shaft at four positions H1 to H4 along the extending direction of the shaft by a single digit value of 0 to 9, and expresses these four values in the extending direction of the shaft. It is the code arranged along. More specifically, four measurement points H1 to H4 are defined at substantially constant intervals in this order from the butt end of the shaft to the tip end. For example, a point 36 inches from the tip end of the shaft can be a measurement point H1, a point 26 inches can be a measurement point H2, a point 16 inches can be a measurement point H3, and a point 6 inches can be a measurement point H4. .. Then, the values of flexural rigidity (hereinafter, may be referred to as EI values) J _{1 to} J ₄ at each of these four measurement points H 1 to H 4 are measured.

Next, the EI values J _{1 to} J _{4 at the above four measurement points H 1 to H 4} are converted into _{rank values K 1 to} K 4 in 10 stages, respectively. Specifically, the rank values K _{1 to} K ₄ can be calculated from the _{EI values J 1 to} J ₄ according to the conversion rules prepared for the respective measurement points H 1 to H 4. _{Then, the four rank values K 1 to} K ₄ assigned to the measurement points H 1 to H 4 in this way have the value corresponding to the butt side to the left and the value corresponding to the chip side to the right. Arrange them so that they come together. The 4-digit code thus obtained is IFC. In IFC, the larger the value of each digit, the higher the rigidity at the corresponding position. In the present embodiment, in consideration of the above IFC, a golf club having a shaft that matches the characteristics of the swing operation of the golfer G is selected.

More specifically, the fitting process according to the present embodiment proceeds as shown in FIG. First, in step S1, measurement data is collected. More specifically, the golfer G swings the test club 4 to which the inertial sensor unit 1 is attached and hits the ball. In this case, the inertial sensor unit 1 includes an acceleration a _x between at least the address to the finish, a _y, a _z, the angular velocity ω _x, ω _y, ω _z and geomagnetism m _x, m _y, time-series data of m _z To measure. This time-series data is transmitted to the fitting device 2 via the communication device 10 as measurement data for measuring the swing motion of the test club 4 by the golfer G. On the other hand, on the fitting device 2 side, the acquisition unit 24A acquires the measurement data via the communication unit 25 and stores it in the storage unit 23.

In the following step S2, the calculation unit 24B is an index representing the characteristics of the swing motion of the golfer G based on the measurement data stored in the storage unit 23, and is a predetermined index B _{1 for selecting the optimum rigidity.} Is calculated. In the present embodiment, the first to fourth feature amounts F _{1 to} F ₄ are calculated as _{such an index B 1.} The first to fourth feature quantities F _{1 to} F ₄ are the optimum EI values J _{S1 to} J _{S4 , which are EI values J 1 to} J ₄ suitable for the golfer G, respectively _{, and the rank values K 1 to} K suitable for the golfer G, respectively. it is an index for selecting an optimum rank value K _S1 ~K _S4 is _four. As is clear from the above, _{the number string in which the optimum rank values K S1 to} K _S4 are arranged from left to right is the optimum rigidity of the present embodiment, that is, the IFC suitable for the golfer G (hereinafter, the optimum IFC). There is a case). Therefore, in the present embodiment, the following feature quantities having a correlation with the optimum EI values J _{S1 to} J _S4 are calculated as the first to _{fourth feature quantities F 1 to F 4, respectively. However, the example of the index B 1} for selecting the optimum rigidity is not limited to this.

The first feature amount F _{1 is the slope of the angular velocity ω y in} the cock direction near the top, and can be expressed by, for example, the sum of _{the angular velocity ω y} 50 ms before the top and the angular velocity ω _y 50 ms after the top.

The second feature amount F ₂ from the top, the angular velocity omega _y is the average value of the angular velocity omega _y up to the point of maximum. For the second feature amount F _{2 , the time point at which the angular velocity ω y} is maximized from the top to the impact is first obtained, and the cumulative value of the angular velocity ω _y from the top to this point is calculated by the time from the top to this point. Calculated by dividing.

The third feature amount F ₃ is the average value of the _{angular velocity ω y} from the time when the angular velocity ω _y becomes maximum to the impact. Third feature amount F ₃ is calculated by the angular velocity omega _y is the cumulative value of the angular velocity omega _y to the impact from the time of maximum, the angular velocity omega _y is divided by the time until the impact from the time of maximum.

The fourth feature amount F ₄ is an average value of the angular velocity omega _y from top to the impact, the cumulative value of the angular velocity omega _y from top to the impact, is calculated by dividing a time from the top to the impact.

By the way, during the swing operation, the shaft of the golf club has a head having a relatively large weight at the tip thereof, so that the shaft is bent due to its inertia. This bending does not occur at the same location on the shaft during the entire swing process, but is transmitted from the top to the tip of the shaft from the top to the impact, as shown in FIG. In other words, as the swing progresses from the top to the impact, the bending position on the shaft moves from the hand side to the tip side of the shaft.

More specifically, when the takeback is performed from the address and the top is reached (the time indicated by (1) in FIG. 5), bending occurs near the hand of the shaft. Then, when turning back and reaching the initial stage of the downswing (the time point shown by (2) in FIG. 5), the bending moves slightly toward the tip end side of the shaft. Further, when the arm of the golfer 7 becomes horizontal (at the time indicated by (3) in FIG. 5), the bending moves toward the tip side of the center of the shaft. Then, immediately before the impact (at the time indicated by (4) in FIG. 5), the bending moves to the vicinity of the tip of the shaft.

Therefore, the first to fourth feature quantities F _{1 to} F ₄ can be calculated based on the measurement data in the first to fourth sections from the vicinity of the top to the vicinity of the impact during the swing operation, respectively. Further, the first to third sections here are sections along the passage of time in this order, and are sections that partially overlap or do not overlap with each other.

In the following step S3, the selection unit 24C selects the optimum rigidity (optimal IFC) according _{to the index B 1} (first to fourth feature amounts F _{1 to} F _{4) calculated in step S2.} In the present embodiment, at this time, the _{optimum EI values J S1} to J S1 to 4 based on the following approximate expression representing the correlation between the first to _{fourth feature quantities F 1 to F 4} and the optimum EI values J _{S1 to} J _S4. J _S4 is calculated.
J _S1 = a ₁ · F ₁ + b ₁
J _S2 = a ₂ · F ₂ + b ₂
J _S3 = a ₃ · F ₃ + b ₃
J _S4 = a ₄ · F ₄ + b ₄

In the above equation, a _{1 to} a ₄ and b _{1 to} b ₄ are constants predetermined by regression analysis based on a large number of experimentally obtained data sets and stored in the storage unit 23 in advance. Since the _{methods for deriving a 1 to} a ₄ and b _{1 to} b ₄ are disclosed in, for example, Patent Document 1 and Japanese Patent Application Laid-Open No. 2013-226375, detailed description thereof will be omitted here.

The selection unit 24C calculates the optimum EI values J _{S1 to} J _S4 by substituting the first to _{fourth feature quantities F 1 to} F 4 calculated in step S2 into the above approximate expression. Subsequently, the selection unit 24C converts the optimum EI values J _{S1 to} J _{S 4} into the optimum rank values K _{S1 to} K _S 4, respectively, according to a predetermined conversion rule. Then, the optimum IFC is determined by combining the optimum rank values K _{S1 to} K _S4.

In the following step S4, the calculation unit 24B is an index representing the characteristics of the swing operation of the golfer G based on the measurement data stored in the storage unit 23, and is a predetermined index C _{1 for selecting the optimum balance.} Is calculated. The index C ₁ is an index representing the amount of change in the degree of opening of the face surface 41a of the head 41 during the swing operation, and includes two indexes C ₁₁ and C ₁₂ defined as follows in the present embodiment.

Here, ω _z _ _imp is the angular velocity ω _z at the timing of impact, and ω _z _ _top is the angular velocity ω _z at the timing of the top. The integral included in C ₁₂ represents the integral from the top timing to the impact timing. 6A and 6B are diagrams illustrating indicators C ₁₁ and C _{12 using actually measured graphs of ω z} and ω _x . The indexes C ₁₁ and C ₁₂ can be calculated based on the data of the _{angular velocities ω x} and ω _z included in the measurement data as defined.

The index C ₁ as described above is calculated in step S4 based on the finding that the amount of change in the degree of opening of the face surface 41a during the swing operation affects the optimum balance. The present inventors obtained this finding through the following experiments.

First, the present inventors had 23 subjects try out two golf clubs with different balances. Of the two golf clubs, one is a golf club with a balance of "D5" (hereinafter sometimes referred to as a normal club), and the other is a golf club with a lighter balance and a balance of "D2". It was a golf club (hereinafter sometimes referred to as a light balance club). The head and shaft are common to the normal club and the light balance club, and a light balance club is prepared by changing the grip of the normal club to a heavier grip.

_{In addition, the present inventors calculated indexes C 11} and C ₁₂ when each of the 23 subjects tried to hit a normal club by the same measuring equipment and measuring method as described above. In addition, for each of the 23 subjects, of the above two golf clubs, the club with the better shot result was identified. The quality of the shot result was evaluated comprehensively by observing the flight distance and directionality (left-right blur). FIG. 7 is a graph summarizing the results. From the experimental results shown in the graph, the golfer index C ₁₁ is small, normally has club better suited to golfers index C ₁₁ is large, a tendency that light balance clubs are more suitable was confirmed .. Furthermore, the golfer small indicator C _12, and light balance club better suited to golfers larger index C _12, a tendency that normal club is more suitable was confirmed. However, although the indexes C ₁₁ and C ₁₂ both represent the amount of change in the opening degree of the face surface 41a during the swing operation, ω _z is more dominant than the opening degree of the face surface 41a _{than ω x.} Is. As a result, the index C ₁₁ showed a stronger tendency than the index C _12.

As a result of the above, as shown in FIG. 7, _{the plane centered on the indexes C 11} and C ₁₂ is divided into a region where the normal club fits and a region where the light balance club fits by the linear boundary line L1. I found out. In FIG. 7, the results that deviate from the above tendency are circled. According to the results of this experiment, the above tendency appeared in 21 out of 23 persons, that is, with a probability of 91% or more. Therefore, it was found that the optimum balance can be determined if the amount of change in the opening degree of the face surface 41a during the swing operation as defined by the indexes C ₁₁ and C _{12 is known.}

Based on the above findings, in the subsequent step S5, the selection unit 24C selects the optimum balance according to the magnitudes _{of the indicators C 11} and C _12. More specifically, the selection unit 24C sets the value of the index C ₁₁ and C ₁₂ calculated in step S4, the two indices C ₁₁ and C ₁₂ are plotted in a plane whose axes, the point plotted, It is determined which region is divided by a predetermined boundary line (see L1 in FIG. 7) in the same plane. Then, the balance associated with the area to which the plotted points belong is selected as the optimum balance. In the example of FIG. 7, the boundary line is one, but one or a plurality of boundary lines can be set here, and the optimum balance is selected from two or three or more balances. Be selected.

In the following step S6, the selection unit 24C selects a golf club having the optimum specifications selected in steps S3 and S5 as the optimum club. That is, a golf club having the optimum rigidity shaft selected in step S3 and having the optimum balance selected in step S5 is selected as the optimum club. More specifically, the selection unit 24C searches the club DB 27, extracts a golf club that meets the conditions of optimum rigidity and optimum balance, and specifies this as the optimum club. Alternatively, the selection unit 24C combines an appropriate head, shaft and grip extracted from the head DB28, the shaft DB29 and the grip DB30 to create a golf club that meets the conditions of optimum rigidity and optimum balance, and optimizes this. It may be specified as a club. At this time, the user may receive input of information indicating the user's wishes regarding the golf club via the input unit 22 and create an optimum club that meets the wishes. For example, the golfer G can specify the type of head he / she likes. At this time, the selection unit 24C extracts information indicating various specifications of the specified type of head from the head DB 28, selects and combines an appropriate shaft and grip from the shaft DB 29 and the grip DB 30 for the head. Therefore, it is possible to create a golf club having the head, having a shaft having the optimum rigidity selected in step S3, and having the optimum balance selected in step S5.

In the following step S7, the display control unit 24D displays the information for identifying the optimum club selected in step S6 on the display unit 21 together with the information on the optimum rigidity and the information on the optimum balance selected in steps S3 and S5, respectively. Display it. A golf club salesperson, an instructor, or the like confirms such information on the display unit 21 together with the golfer G, and recommends the golf club to the golf club having a shaft having the optimum rigidity and having the optimum balance. With the above, the fitting process is completed.

<2. Second Embodiment>
Next, the fitting process according to the second embodiment will be described with reference to FIG. The main difference between the first embodiment and the second embodiment is that the index for selecting the optimum balance is different. Hereinafter, the description of the common points with the first embodiment will be omitted, and the second embodiment will be described focusing on the differences between the two embodiments.

More specifically, in the second embodiment, as an index for selecting the optimal balance, in addition to an index C ₁ described above, preliminary indicator of the different characteristics of the swing motion of the golfer G is calculated (step S41 ). Preliminary indicators are indicators that are preliminarily considered to select the optimal balance. In the second embodiment, the optimum balance is determined according to the combination of _{the index C 1 and the preliminary index (step S5).} The preliminary index of the present embodiment is the power (hereinafter referred to as arm output power) P ₁ output by the arm of the golfer G during the swing operation. The arm output power P ₁ is a known index described in detail in Patent Document 1 and the like, and can be defined as shown in the following equation.

Here, T _g1 means the torque around the center of gravity of the golfer's arm, T _g2 means the torque around the center of gravity of the golf club, and ω ₁ means the angular velocity of the golfer G's arm. The arm output power P ₁ can be analyzed using a pendulum model with arms and golf clubs as links and shoulders and grips as nodes, as shown in FIG. Although not limited to this, the preliminary index according to the present embodiment _{integrates the arm output power P 1 in the section from the top time to the time when the arm output power P 1} takes the maximum value, and integrates this integrated value. _{It is calculated as the average arm output power P 1} (hereinafter, sometimes referred to as _{P 1} _ _AVE ) during the swing motion, which is calculated by dividing by the interval.

_{In FIG. 10, the arm output power P 1} _ _AVE is calculated from the measurement data acquired in the same experiment as in FIG. 7, and the arm output power P ₁ _ _AVE and the index C ₁₁ are in a plane about both axes. The result plotted in is shown. From the figure, even when the index C ₁₁ and the arm output power P ₁ _ _AVE are used, the golfer who fits the normal club and the golfer who fits the light balance club are stratified with the same high probability as in the case of Fig. 7. It was confirmed that it could be done. Therefore, the index C ₁ representing the amount of change in opening degree of the face surface 41a of the head 41 during the swing operation, by combining the arm output power P _1, it was found that the optimum balance is accurately determinable.

Based on the above findings, the fitting process according to the second embodiment proceeds as shown in FIG. Steps S1 to S3 are the same as those in the first embodiment. Step S4 is also substantially the same as that of the first embodiment, but the calculation of the _{index C 12 is omitted, and only the index C 11} is calculated. In the subsequent step S41, the selection unit 24C calculates the _{arm output power P 1} _ _AVE , which is a preliminary index, based on the measurement data stored in the storage unit 23.

In step S5, the selection unit 24C in accordance with the magnitude of the index C ₁ and preliminary indicator of the amount of change in opening degree of the face surface 41a, selects an optimum balance. More specifically, the selection unit 24C may each calculated value of the index C ₁₁ and P ₁ _ _AVE at step S4 and S41, both indices C ₁₁ and P ₁ _ _AVE plotted in a plane whose axes , It is determined which region the plotted points belong to, which is divided by a predetermined boundary line (see L1 in FIG. 10) in the same plane. Then, the balance associated with the area to which the plotted points belong is selected as the optimum balance. In the example of FIG. 10, the boundary line is one, but one or a plurality of boundary lines can be set here, and the optimum balance is selected from two or three or more balances. Be selected. Steps S6 and S7 after the optimum balance is selected are the same as in the first embodiment.

<3. Third Embodiment>
11 and 12 show the overall configuration of the fitting system 200 having the fitting device 102 according to the third embodiment. The main difference between the first and second embodiments and the third embodiment is that the indexes for selecting the optimum balance are different. Further, the configuration of the measuring device for measuring the measurement data for calculating such an index is also different. Hereinafter, the description of the common points with the first and second embodiments will be omitted, and the third embodiment will be described focusing on the differences between these embodiments.

In the third embodiment, the measuring device that measures the swing motion is the camera system 5. The camera system 5 is installed in a turn at bat where the golfer G makes a trial hit at a specialized place such as a golf equipment store or a golf school, and measures the swing motion of the golfer G standing in the turn at bat. As shown in FIGS. 11 and 12, the camera system 5 includes a plurality of cameras 51 and 52 and a plurality of strobes 53, 53, 54 and 54, and performs strobe-type shooting. The camera 51 is fixed to the support base 57 on the front side of the golfer G so that the state of the head 41 and the ball 60 before and after the impact can be photographed from above, and is arranged diagonally above the ball 60 at the time of addressing. There is. The strobes 53 and 53 are also fixed to the support base 57 and are arranged below the camera 51. Further, the camera 52 is arranged in front of the ball 60 at the time of addressing on the front side of the golfer G so that the state of the head 41 and the ball 60 before and after the impact can be photographed from a position different from that of the camera 51. The strobes 54 and 54 are arranged on the left and right sides of the camera 52. The head 41 and the golf ball 60 are appropriately provided with markers having a shape such as a dot or a line so that the behavior of the head 41 and the ball 60 can be easily extracted from the image data taken by the cameras 51 and 52. Has been done.

Further, the camera system 5 includes floodlights 55A and 55B and receivers 56A and 56B, the floodlight 55A and the receiver 56A constitute one timing sensor, and the floodlight 55B and the receiver 56B have another timing. It constitutes a sensor. The timing signals generated by these timing sensors are used to determine the timing of light emission of strobes 53, 53, 54 and 54 and subsequent shooting of cameras 51 and 52.

Further, the camera system 5 also includes a control device 50 for controlling the operation of the above devices 51 to 56B. The control device 50 has a CPU, a ROM, a RAM, and the like, and is connected to the communication unit 25 of the fitting device 102 in addition to the above devices 51 to 56B.

The floodlights 55A and 55B are arranged below the camera 51 near the ground on the front side of the golfer G. On the other hand, the receivers 56A and 56B are arranged near the toes of the golfer G's foot. The floodlight 55A and the receiver 56A are arranged on a straight line substantially parallel to the direction from the back to the abdomen of the golfer G, and face each other (see FIG. 11). The same applies to the floodlight 55B and the receiver 56B. The floodlights 55A and 55B constantly irradiate the light receivers 56A and 56B, respectively, during the swing operation by the golfer G, and the light receivers 56A and 56B receive the light. However, at the timing when the test club 4 passes between the floodlights 55A and 55B and the receivers 56A and 56B, the light from the floodlights 55A and 55B is blocked by the test club 4, so that the receivers 56A and 56B receive the light. Can not do it. The receivers 56A and 56B detect this timing and generate a timing signal in response to this timing. The control device 50 commands the strobes 53, 53, 54, and 54 to emit light and commands the cameras 51 and 52 to shoot at a predetermined timing based on the time when the timing signal is generated. The measurement data in the form of image data captured by the cameras 51 and 52 is transmitted to the control device 50, and is further transmitted from the control device 50 to the fitting device 102.

Next, an index for selecting the optimum balance according to the third embodiment will be described. As described above, according to the findings obtained by the present inventors, the amount of change in the degree of opening of the face surface 41a during the swing operation affects the optimum balance. Therefore, in the third embodiment, the index C ₁₃ representing the amount of change in the face angle is calculated as an index for selecting the optimum balance. The index C _{13 is also an index C 1} indicating the amount of change in the degree of opening of the face surface 41a during the swing operation, similarly to the _{indexes C 11} and C _{12 according} to the first and second embodiments. _{In the present embodiment, as shown in FIG. 13, the face angle FA 1} at the first position separated from the ball 60 at the time of addressing by a predetermined distance and the ball 60 are closer than the first position, but the ball 60 is still present. _{The face angle FA 2} at the second position separated from the above by a predetermined distance is calculated, and the index C ₁₃ is calculated as the difference FA _{1 − FA 2} . Both the first position and the second position are positions through which the test club 4 passes immediately before the impact.

In the present embodiment, the index C ₁₃ is calculated by image processing the measurement data, which is the image data captured by the camera system 5. As shown in FIG. 13, in the present embodiment, a band-shaped marker M1 is attached to the crown portion of the head 41 along the face surface 41a so that the face angle can be easily grasped. The marker M1 is made of a material that efficiently reflects light from the strobes 53 and 54. Therefore, on the images taken by the cameras 51 and 52, the region of the marker M1, in other words, the strip-shaped region along the face surface 41a is clearly reflected in the plan view of the head 41. The calculation unit 24B displays an image of the marker M1 on two images (images at the first position and the second position) at the timing of light emission of the strobes 53 and 54 immediately before the impact stored in the storage unit 23. Extract. Then, based on the images of these markers M1, the face angles FA ₁ and FA ₂ are calculated, and the index C ₁₃ = FA _{1 − FA 2} is calculated.

The present inventors conducted an experiment in which 27 subjects were made to try out two golf clubs, a normal club and a light balance club described above. Then, each of the 27 subjects _{calculated the index C 13} when the normal club was hit by the same measuring device and measuring method as described above. In addition, for each of the 27 subjects, of the above two golf clubs, the club with the better shot result was identified. The quality of the shot result was determined in the same manner as in the first embodiment. FIG. 14 is a table summarizing the results. From the experimental results shown in the table, the golfer index C ₁₃ is small, normally has club better suited to golfers same index C ₁₃ is large, a tendency that light balance clubs are more suitable is confirmed It was. In FIG. 14, _{the threshold value for determining the magnitude of the index C 13} is set to 6 deg, and the result that deviates from the above tendency is colored with a background. According to the results of this experiment, the above tendency appeared in 24 out of 27 persons, that is, with a probability of 88% or more. Therefore, it was found that the optimum balance can be determined if the _{index C 13} indicating the amount of change in the degree of opening of the face surface is known.

The fitting process according to the third embodiment proceeds as shown in FIG. 4, similarly to the first embodiment. _{However, based on the above findings, in step S4, the calculation unit 24B sets the index C 11} as the index C ₁ indicating the amount of change in the opening degree of the face surface 41a based on the measurement data stored in the storage unit 23. And C ₁₂ but index C ₁₃ is calculated.

In the following step S5, the selection unit 24C selects the optimum balance according to the magnitude of _{the index C 13.} More specifically, the selection unit 24C selects a lighter optimum balance as the _{index C 13 is larger.} At this time, the selection unit 24C _{compares the index C 13} with a predetermined threshold value of 1 or a plurality of threshold values determined stepwise, and the index C ₁₃ is in any range with the threshold value as a boundary. Judge whether it belongs to, and select a lighter optimum balance as it belongs to a larger range. Steps S6 and S7 after the optimum balance is selected are the same as in the first embodiment.

<4. Modification example>
Although some embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, the following changes can be made. In addition, the gist of the following modified examples can be combined as appropriate.

<4-1>
In the above embodiment, the inertial sensor unit 1 or the camera system 5 is used as the measuring device for measuring the swing motion. However, the configuration of the measuring device is not limited to this, and can be changed as appropriate. For example, a three-dimensional motion capture system, a distance image sensor, or the like may be used, or a plurality of types of measuring devices may be selected from the measuring devices exemplified here or other measuring devices, and these may be used in combination.

<4-2>
In the above embodiment, in step S7, all of the information for identifying the optimum club, the information for the optimum balance, and the information for the optimum rigidity are displayed on the display unit 21, but only a part of them may be displayed. For example, when only the information on the optimum balance and the optimum rigidity is displayed, the golf club salesperson or the instructor who sees this information searches the catalog etc. for the golf club that matches the optimum balance and the optimum rigidity, and the golfer G May be recommended for. If the information for identifying the optimum club is not displayed in step 7, step S6 can be omitted. Further, in addition to step S6, at least one of steps S3 and S5 can be omitted. In this case, _{by appropriately displaying the indicators B 1} , C ₁ , and the preliminary indicators in step S7, a person can perform the omitted steps while referring to the information prepared in advance indicating the relationship between these indicators and the optimum specifications. You can also do it.

Further, the selection unit 24C derives a customization method for customizing a specific golf club having a shaft having optimum rigidity so as to achieve the optimum balance, and the display control unit 24D displays this on the display unit 21. You may. For example, while displaying information that identifies a shaft with optimum rigidity, the weight of the weight to be attached to the grip or head of a specific golf club equipped with the shaft is calculated and customized in order to achieve the optimum balance. It may be displayed as a method.

<4-3>
_{The index C 1} representing the amount of change in the degree of opening of the face surface 41a during the swing operation described above is an example, and can be appropriately changed. For example, instead of the indicator C _11, 'can either be used in place of the indicator C _12, the following indicators C _12' following indicators C ₁₁ can also be used. Also, 'to a start point and an end point of the integration interval can alternatively be set to a timing other than the top and impact, C ₁₁ and C _12' C ₁₂ and C ₁₁ difference other than the top and impact the timing of the angular velocity to be taken of It can also be set to the timing.

In the first embodiment, 'the index relating omega _z, such as, C ₁₂ and C _12' C ₁₁ and C ₁₁ is not necessary to combine the metrics for such omega _x as, one of the omega _z or omega _x The optimum balance may be selected according to only the index related to. However, in this case, it is desirable to use an index related _{to ω z, which is} more dominant with respect to the amount of change in the degree of opening of the face surface 41a, as in the second embodiment.

Although various indexes C ₁ including the index C ₁₃ have been described above, the optimum balance can be determined according to one or a plurality of combinations thereof.

<4-4>
In the above embodiment, the arm output power P _{1 is illustrated as a preliminary index used in combination with the index C 1} to select the optimum balance, but other indexes can also be used. For example, in addition to the arm output power P ₁ , the optimum balance can be determined when the index C _{1 is combined with the following preliminary indexes.}
-Power input to the test club 4 during swing operation (hereinafter referred to as club input power) P ₂
・ Energy exerted by golfer G during swing operation (hereinafter referred to as exerted energy) E ₁
-Torque exerted by golfer G during swing operation (hereinafter referred to as exerted torque) T

The club input power P ₂ is a known index which is described in detail in Patent Document 1 and the like, and can be defined as shown in the following equation.

Here, R ₂ is a binding force generated in the grip, and v _g is a velocity vector of the grip. The club input power P ₂ can also be analyzed using a pendulum model with arms and golf clubs as links and shoulders and grips as nodes, as shown in FIG. Although not limited to, the club input power P ₂ as the pre-index can be calculated as the average club input power P ₂ during the swing operation, for example, clubs input power P ₂ from the time of the top _{It can be calculated by integrating the club input power P 2} in the interval up to the time when the maximum value is taken and dividing this integrated value by the integration interval.

The exerted energy E _{1 is} also a known index described in detail in Patent Document 1 and the like. For example, the amount of work exerted by the golfer G's arm or the exerted energy per unit time by the golfer G's arm is averagely exerted. Can be defined as the average workload. Workload arms, for example, 'from a predetermined time period (e.g., the top of the time, the arm work rate in the subsequent top E _1' arm of work rate E ₁ as described below until the time turns from positive to negative ) Can be calculated, and the average work of the arm can be calculated as a value obtained by dividing such an integrated value by the length of the integration interval.

The exerted torque T is also a known index described in detail in Patent Document 1 and the like, and is defined as, for example, an integrated value obtained by integrating the torque around the shoulder of the golfer G in a predetermined period (for example, from the top to the impact). Alternatively, it can be defined as a value obtained by dividing this integrated value by the length of the integrated interval, that is, the average torque around the shoulder that is exerted on average per unit time.

Having described the various preliminary indicators, one or more optional indicator C ₁ described above, by combining one or more of these preliminary indicators as appropriate, can determine the optimal balance.

<4-5>
In the above embodiment, the flexural rigidity is evaluated as the rigidity of the shaft, but instead, the torsional rigidity may be evaluated. The value of torsional rigidity (hereinafter, may be referred to as GJ value) can also be evaluated at a plurality of positions along the extending direction of the shaft. That is, the distribution of the torsional rigidity at a plurality of positions along the extending direction of the shaft may be used as the rigidity of the shaft. _{In this case, as a predetermined index B 1} for selecting the optimum rigidity (that is, the optimum GJ value which is the GJ value suitable for the golfer G), any index whose correlation with the optimum GJ value is recognized may be used. it can. As such an index, for example, the following index as described in Japanese Patent Application Laid-Open No. 2014-212862 can be used.

(1) The _{amount of change in the grip angular velocity ω x} per unit time from the time when the _{grip angular velocity ω y} is maximized to the impact (2) The amount of change in the grip angular velocity ω _z near the top (3) Down from the top The amount of change in the grip angular velocity ω _{z during} the swing until the grip angular velocity ω _{y becomes maximum}

Also in this modified example, _{an approximate expression representing the relationship between the index B 1} and the optimum GJ value is calculated in advance by an experiment and stored in the storage unit 23, so that the optimum GJ value is obtained from the _{index B 1 based on the measurement data.} Can be determined.

Further, as the optimum rigidity, the flex, tone or torque of the shaft suitable for the golfer G may be determined instead of the rigidity distribution at a plurality of positions of the shaft suitable for the golfer G. The flex is an index for evaluating the hardness (flexural rigidity) of the entire shaft, and the torque is an index for evaluating the torsional rigidity of the entire shaft. The method for deriving the flex (optimal flex) suitable for the golfer G is not particularly limited, but can be calculated from, for example, the above-mentioned optimum EI value. For example, the optimum EI value at a specific position may be the optimum flex, or the average value of the optimum EI values at a plurality of positions may be the optimum flex. Similarly, the torque suitable for the golfer G (optimal torque) can be appropriately calculated from the optimum GJ value, and the tone suitable for the golfer (optimal tone) can also be appropriately calculated from the optimum EI value and the optimum GJ value. Can be calculated.

100,200 Fitting system 1 Inertia sensor unit (measuring equipment)
2,102 Fitting device 24A Acquisition unit 24B Calculation unit 24C Selection unit 24D Display control unit 3 Fitting program 4 Test club 40 Shaft 41 Head 42 Grip 5 Camera system (measuring equipment)
G golfer

Claims (9)

An acquisition unit that acquires measurement data obtained by measuring the swing motion of a test club by a golfer with a measuring device,
Based on the measurement data, a calculation unit that calculates one or a plurality of first indexes representing the amount of change in the opening degree of the face surface of the head included in the test club during the swing operation, and a calculation unit.
A fitting device including a selection unit for selecting a golf club balance suitable for the golfer according to the one or a plurality of first indexes. The calculation unit calculates the first index based on the angular velocity data around the axis substantially parallel to the shaft of the test club included in the measurement data.
The fitting device according to claim 1. The calculation unit calculates the first index based on the angular velocity data around the axis substantially parallel to the toe-heel direction of the test club included in the measurement data.
The fitting device according to claim 1 or 2. The angular velocity data is data measured by an angular velocity sensor attached to the test club, which is included in the measuring device.
The fitting device according to claim 2 or 3. Based on the measurement data, the calculation unit calculates one or a plurality of preliminary indexes representing the characteristics of the swing motion, which are different from the one or a plurality of first indexes.
The selection unit selects the balance according to the one or a plurality of preliminary indexes in addition to the one or a plurality of first indexes.
The fitting device according to any one of claims 1 to 4. The one or a plurality of preliminary indexes include an index indicating the power output by the golfer's arm during the swing operation, an index indicating the power input to the test club during the swing operation, and the golfer exerting the power during the swing operation. It includes at least one index indicating the energy to be generated and an index indicating the torque exerted by the golfer during the swing operation.
The fitting device according to claim 5. Based on the measurement data, the calculation unit calculates one or a plurality of second indexes representing the characteristics of the swing motion, which are different from the one or a plurality of first indexes.
The selection unit selects the rigidity of the shaft suitable for the golfer according to the one or a plurality of second indexes.
The fitting device according to any one of claims 1 to 6. Acquiring measurement data obtained by measuring the swing motion of a test club by a golfer with a measuring device,
Based on the measurement data, one or a plurality of first indexes representing the amount of change in the opening degree of the face surface of the head included in the test club during the swing operation are calculated.
A fitting program that causes a computer to select a golf club balance suitable for the golfer according to the one or more first indicators. Acquiring measurement data that measures the swing motion of a test club by a golfer using a measuring device,
Using a computer, one or a plurality of first indexes representing the amount of change in the degree of opening of the face surface of the head included in the test club during the swing operation are calculated based on the measurement data.
A fitting method comprising recommending to the golfer a balance of golf clubs suitable for the golfer, which is determined according to the one or more first indicators.

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