JP2017023690A - Fitting device of golf club, method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fitting device capable of objectively and accurately determining an optimum swing easiness index which is a swing easiness index of a golf club suitable for a golfer.SOLUTION: A fitting device for determining an optimum swing easiness index is provided. The fitting device comprises an acquisition unit, a calculation unit, and a determination unit. The acquisition unit acquires a measurement value of which a swing motion of a test club by a golfer is measured by a measurement instrument. The calculation unit calculates a swing index on the basis of the measurement value. The swing index includes at least one of an index indicating power output from arms of the golfer during the swing motion and an index indicating power input to the test club during the swing motion. The determination unit determines the optimum swing easiness index according to the magnitude of the swing index.SELECTED DRAWING: Figure 14

Description

  The present invention relates to a fitting device, a method, and a program for determining a golf club swingability index (hereinafter referred to as an optimal swingability index) suitable for a golfer. The present invention also relates to a fitting apparatus, method, and program for determining an index (hereinafter referred to as an optimal characteristic index) representing characteristics of a specific part of a golf club suitable for a golfer.

  2. Description of the Related Art Conventionally, various fitting methods have been proposed in which a golf club is made a test club and the movement thereof is measured by a measuring device, and a golf club suitable for the golfer is determined based on the measured value. Patent Document 1 points out that it is important to consider the weight of the golf club, the length of the golf club, and the like in order to select a golf club suitable for the golfer.

JP 2013-226375 A

  The weight of the golf club is one index representing the ease of swinging the golf club. By the way, at the time of fitting, the weight of the golf club suitable for the golfer (hereinafter referred to as the optimum club weight) may be determined. The optimum club weight is determined by the weight of the golf club currently used by the golfer, In many cases, it is empirically determined by a skilled club fitter based on the result of a golf club trial hit, an apparent swing tempo, and the like. However, such a fitting method that depends on experience and intuition is not objective, and there is a problem that individual differences occur in the fitting results.

  In addition, the present inventors considered that it is important to pay attention to a swing ease index other than the weight of the golf club in order to determine a golf club suitable for a golfer by fitting. Furthermore, it is important to improve the accuracy of fitting by selecting the feature value of the golfer's swing motion (hereinafter referred to as the swing index), which should be noted in order to determine the optimal swing ease index. We proceeded with the examination.

  Furthermore, in order to determine a golf club suitable for a golfer by fitting, the present inventors not only pay attention to the characteristics of the entire golf club but also to pay attention to the characteristics of a specific part of the golf club. I thought.

  An object of the present invention is to provide a fitting device, a method, and a program that objectively and accurately determine an optimal swingability index that is a golf club swingability index suitable for a golfer. Another object of the present invention is to provide a fitting device, method, and program for objectively and accurately determining an optimum characteristic index that represents the characteristic of a specific part of a golf club suitable for a golfer.

  A fitting device according to a first aspect of the present invention is a fitting device that determines an optimal swingability index that is a golf club swingability index suitable for a golfer, and includes an acquisition unit, a calculation unit, and a determination unit. Is provided. The acquisition unit acquires a measurement value obtained by measuring a swing motion of a test club by the golfer using a measuring device. The calculation unit calculates a swing index based on the measurement value. The swing index includes at least one of an index indicating power output from the golfer's arm during the swing operation and an index indicating power input to the test club during the swing operation. The determination unit determines the optimal swing ease index according to the size of the swing index.

  The fitting apparatus which concerns on the 2nd viewpoint of this invention is a fitting apparatus which concerns on a 1st viewpoint, Comprising: The said calculation part calculates the said kind of said swing parameter | index. The determining unit determines the optimum swing ease index according to the sizes of the plurality of types of swing indices.

  A fitting device according to a third aspect of the present invention is the fitting device according to the second aspect, wherein the swing index includes an index indicating power output by the golfer's arm during the swing operation, and during the swing operation. An index indicating power input to the test club is included.

  A fitting device according to a fourth aspect of the present invention is the fitting device according to any one of the first to third aspects, wherein the swing index includes a head speed during the swing operation. The determination unit determines the optimal swingability index according to the magnitude of the head speed.

  A fitting device according to a fifth aspect of the present invention is the fitting device according to any one of the first to fourth aspects, wherein the determination unit increases the optimal swingability index as the swing index is larger or smaller. Is determined to be a large value.

  A fitting device according to a sixth aspect of the present invention is the fitting device according to any one of the first to fifth aspects, wherein the magnitude of the swing index and the optimal swing ease index for each type of the test club A storage unit is further provided for storing correspondence data for determining a correspondence relationship with the size of the. The determination unit determines the optimal swingability index by referring to the correspondence relationship data in the storage unit according to the type of the test club.

  A fitting device according to a seventh aspect of the present invention is the fitting device according to any one of the first to sixth aspects, wherein the ease of swing index includes the moment of inertia around the golfer's shoulder, the golf club And at least one of the weight of the golf club.

A fitting method according to an eighth aspect of the present invention is a fitting method for determining an optimum swingability index that is a golf club swingability index suitable for a golfer, and includes the following steps (1) to (3): including.
(1) A step of measuring a swing motion of the test club by the golfer with a measuring device.
(2) A step of calculating a swing index based on a measured value by the measuring device.
(3) A step of determining the optimum swing ease index according to the size of the swing index.
The swing index includes at least one of an index indicating power output by the golfer's arm during the swing operation and an index indicating power input to the test club during the swing operation.

A fitting program according to a ninth aspect of the present invention is a fitting program for determining an optimal swingability index that is a golf club swingability index suitable for a golfer, and includes the following steps (1) to (3): Is executed on the computer.
(1) A step of acquiring a measured value obtained by measuring a swing motion of the test club by the golfer with a measuring device.
(2) A step of calculating a swing index based on a measured value by the measuring device.
(3) A step of determining the optimum swing ease index according to the size of the swing index.
The swing index includes at least one of an index indicating power output by the golfer's arm during the swing operation and an index indicating power input to the test club during the swing operation.

  A fitting device according to a tenth aspect of the present invention is a fitting device that determines an optimum characteristic index representing a characteristic of a specific part of a golf club suitable for a golfer, and includes an acquisition unit, a calculation unit, and a determination unit. Prepare. The acquisition unit acquires a measurement value obtained by measuring a swing motion of a test club by the golfer using a measuring device. The calculation unit includes at least one of an index indicating power output from the golfer's arm during the swing operation and an index indicating power input to the test club during the swing operation based on the measurement value. A swing index is calculated. The determining unit determines the optimum characteristic index according to the magnitude of the swing index.

  The fitting apparatus which concerns on the 11th viewpoint of this invention is a fitting apparatus which concerns on a 10th viewpoint, Comprising: The said specific site | part is a shaft or a grip.

  A fitting apparatus according to a twelfth aspect of the present invention is the fitting apparatus according to the tenth aspect or the eleventh aspect, wherein the determining unit is suitable for the golfer according to the size of the swing index. The optimal swingability index, which is a swing ease index, is determined, and the optimal characteristic index is determined according to the size of the optimal swingability index.

  A fitting apparatus according to a thirteenth aspect of the present invention is the fitting apparatus according to the twelfth aspect, wherein the determining unit uses a predetermined regression equation that uses the swing index as an explanatory variable and the optimal swingability index as a target variable. Then, the optimum swing ease index is calculated by substituting the swing index calculated by the calculation unit.

  A fitting device according to a fourteenth aspect of the present invention is the fitting device according to the tenth aspect or the eleventh aspect, wherein the determining unit uses the swing index as an explanatory variable and the optimum characteristic index is a predetermined variable. The optimum characteristic index is calculated by substituting the swing index calculated by the calculation unit into a regression equation.

  The inventors of the present invention describe an optimal swing ease index, an index indicating the power output by the golfer's arm during the swing operation (hereinafter referred to as arm output power), and the power input to the golf club during the swing operation (hereinafter referred to as the club). It was discovered that there is a correlation with an index indicating (input power). Therefore, according to the present invention, the optimal swingability index is determined according to the magnitude of the swing index including at least one of the index indicating the arm output power and the club input power. Thereby, the optimal swing ease index can be objectively determined with high accuracy.

  The inventors have also found that there is a correlation between the optimum characteristic index, the index indicating the arm output power, and the index indicating the club input power. Therefore, according to the present invention, the optimum characteristic index is determined according to the magnitude of the swing index including at least one of the index indicating the arm output power and the club input power. Thereby, the optimum characteristic index can be objectively determined with high accuracy.

The figure which shows a golf swing system provided with the fitting apparatus which concerns on 1st Embodiment of this invention. The functional block diagram of a fitting system. The figure explaining xyz local coordinate system on the basis of the grip of a golf club. The flowchart which shows the flow of the analysis process of swing operation | movement. (A) The figure which shows an address state. (B) The figure which shows a top state. (C) The figure which shows an impact state. (D) The figure which shows a finish state. The flowchart which shows the flow of a 1st conversion process. The flowchart which shows the flow of the process which derives | leads-out the time of an address. The figure explaining a swing plane. The flowchart which shows the flow of a shoulder behavior derivation | leading-out process. The figure which illustrates a double pendulum model notionally. The flowchart which shows the flow of an parameter | index calculation process. Another diagram conceptually explaining the double pendulum model. The figure explaining arm energy. The flowchart which shows the flow of the optimal swing MI determination process. The figure which shows the pro model area | region divided | segmented into the division area corresponding to the optimal swing MI band. The figure which shows the average model area | region divided | segmented into the division area corresponding to the optimal swing MI band. The functional block diagram of the fitting system which concerns on 2nd Embodiment of this invention. The flowchart which shows the flow of the optimal grip end MI determination process. The figure which shows the pro model area | region divided | segmented into the division area corresponding to the optimal grip end MI band. The figure which shows the average model area | region divided | segmented into the division area corresponding to the optimal grip end MI band. The functional block diagram of the fitting system which concerns on 3rd Embodiment of this invention. The flowchart which shows the flow of the optimal club weight determination process. The figure which shows the pro model area | region divided | segmented into the division area corresponding to the optimal club weight belt. The figure which shows the average model area | region divided | segmented into the division area corresponding to the optimal club weight belt. A graph plotting the relationship between I _G and I _S of various golf clubs. A graph plotting the relationship between m ₂ and I _S of various golf clubs. The functional block diagram of the fitting system which concerns on 4th Embodiment. The flowchart which shows the flow of the analysis process of the swing action which concerns on 4th Embodiment. The flowchart which shows the flow of the optimal shaft weight determination process. The figure which illustrates notionally the shoulder behavior derivation | leading-out process which concerns on a modification. The other figure which illustrates notionally the shoulder behavior derivation | leading-out process which concerns on a modification. The figure which shows the simulation result of the double pendulum model which concerns on 1st Embodiment. The figure which shows the simulation result of the double pendulum model which concerns on a modification. The figure which shows the space which shows the swing parameter | index divided | segmented into the division area corresponding to the optimal shaft weight belt.

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

<1. First Embodiment>
<1-1. Schematic configuration of fitting system>
1 and 2 show an overall configuration of a fitting system 100 including a fitting device 2 according to the present embodiment. The fitting device 2 is a device that analyzes the swing motion of the golf club 4 based on measurement data obtained by measuring the swing motion of the golf club 4 by the golfer 7. In the present embodiment, the fitting device 2 is used for the purpose of supporting the fitting of the golf club 4. The measurement of the swing motion is performed by the sensor unit 1 (measuring device) attached to the grip 42 of the golf club 4, and the fitting device 2 constitutes the fitting system 100 together with the sensor unit 1.

  Hereinafter, after describing the configuration of the sensor unit 1 and the fitting device 2, the flow of the analysis process of the swing operation will be described.

<1-1-1. Configuration of sensor unit>
As shown in FIGS. 1 and 3, the sensor unit 1 is attached to an end portion of the grip 42 of the golf club 4 opposite to the head 41 and measures the behavior of the grip 42. The golf 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. The sensor unit 1 is configured to be small and light so as not to hinder the swing operation. As shown in FIG. 2, an acceleration sensor 11, an angular velocity sensor 12, and a geomagnetic sensor 13 are mounted on the sensor unit 1 according to the present embodiment. The sensor unit 1 is also equipped with a communication device 10 for transmitting measurement data from these sensors 11 to 13 to the external fitting device 2. In the present embodiment, the communication device 10 is wireless so as not to hinder the swing operation, but may be connected to the fitting device 2 in a wired manner via a cable.

The acceleration sensor 11, the angular velocity sensor 12, and the geomagnetic sensor 13 respectively measure grip acceleration, grip angular velocity, and grip geomagnetism in the xyz station coordinate system with the grip 42 as a reference. More specifically, the acceleration sensor 11 measures grip accelerations a _x , a _y , and a _z in the x-axis, y-axis, and z-axis directions. The angular velocity sensor 12 measures grip angular velocities ω _x , ω _y , and ω _z around the x axis, the y axis, and the z axis. Geomagnetic sensor 13 measures the x-axis, y-axis and z-axis direction of the grip geomagnetism m _x, m _y, a m _z. These measurement data are acquired as time-series data of a predetermined sampling period Δt. The xyz local coordinate system is a three-axis orthogonal coordinate system defined as shown in FIG. That is, the z axis coincides with the direction in which the shaft 40 extends, and the direction from the head 41 toward the grip 42 is the z axis positive direction. The x-axis is oriented as much as possible in the toe-heel direction of the head 41, and the y-axis is oriented as much as possible in the normal direction of the face surface of the head 41.

  In the present embodiment, measurement data obtained by the acceleration sensor 11, the angular velocity sensor 12, and the geomagnetic sensor 13 are transmitted to the fitting device 2 in real time via the communication device 10. However, for example, the measurement data may be stored in a storage device in the sensor unit 1, and the measurement data may be taken out from the storage device after the swing operation is finished and transferred to the fitting device 2.

<1-1-2. Configuration of fitting device>
The configuration of the fitting device 2 will be described with reference to FIG. The fitting device 2 is manufactured by installing the fitting program 3 according to the present embodiment stored in a computer-readable recording medium 20 such as a CD-ROM or USB memory from the recording medium 20 to a general-purpose personal computer. Is done. The fitting program 3 is software for analyzing the swing motion based on the measurement data sent from the sensor unit 1 and outputting information that assists in selecting a golf club suitable for the golfer 7. The fitting program 3 causes the fitting apparatus 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 the bus line 26 and can communicate with each other. In the present embodiment, the display unit 21 is configured with a liquid crystal display or the like, and displays information to be described later to the user. In addition, a user here is a general term for the person who requires the result of fitting, such as golfer 7 himself or its instructor. The input unit 22 can be configured with a mouse, a keyboard, a touch panel, and the like, and accepts an operation from the user on the fitting device 2.

  The storage unit 23 is configured by a nonvolatile storage device such as a hard disk. The storage unit 23 stores the fitting program 3 and the measurement data sent from the sensor unit 1. The storage unit 23 stores correspondence data 28. The correspondence relationship data 28, which will be described in detail later, is specified for each golf club 4 of various models, and determines the swing inertia moment (hereinafter referred to as the optimal swing MI) suitable for the golfer as an optimal swing ease index. It is the data which shows the conditions for doing. The swing inertia moment will be described later. The communication unit 25 is a communication interface that enables communication between the fitting device 2 and an external device, and receives data from the sensor unit 1.

  The control unit 24 can be composed of a CPU, ROM, RAM, and the like. The control unit 24 reads and executes the fitting program 3 in the storage unit 23 to virtually acquire the acquisition unit 24A, the grip behavior deriving unit 24B, the shoulder behavior deriving unit 24C, the index calculating unit 24D, the determining unit 24E, and the display It operates as the control unit 24F. Details of the operations of the units 24A to 24F will be described later.

<1-2. Analysis of swing motion>
Next, a swing operation analysis process for fitting the golf club 4 by the fitting system 100 will be described. The analysis processing according to the present embodiment includes the following six steps as shown in FIG.
(S1) grip acceleration a _x in the xyz local coordinate system, a _y, a _z, grip angular velocity ω _x, ω _y, ω _z and grip geomagnetism m _x, m _y, measuring step of measuring the measurement data m _z ( S2) First, the measurement data in the xyz local coordinate system obtained in the measurement process is converted into grip accelerations a _X , a _Y , a _Z and grip angular velocities ω _X , ω _Y , ω _Z in the XYZ global coordinate system. Conversion step (In the first conversion step, grip speeds v _X , v _Y , and v _Z in the XYZ global coordinate system are also derived.)
(S3) The behavior of the grip 42 in the XYZ global coordinate system (grip angular velocities ω _X , ω _Y , ω _Z and grip velocities v _X , v _Y , v _Z ) is determined from the grip 42 in the swing plane P (described later). 2nd conversion process (S4) which converts into the behavior of the shoulder Based on the behavior of the grip 42 in the swing plane P, the shoulder behavior derivation process for deriving the pseudo shoulder behavior of the golfer 7 in the swing plane P ( S5) Based on the behavior of the grip 42 and the pseudo shoulder behavior, the swing index (in this embodiment, the optimal swing MI) for determining the optimal swing ease index (in this embodiment, exhibited by the golfer 7). that arms output power P ₁ _ _AVE, club input power P ₂ _ _AVE and index calculation step of calculating the three indicators) a head velocity V _h (S6) based on the swing indicator, to determine the optimum swing MI Suitable swing MI determining step will be described below these steps in order.

  The XYZ global coordinate system is a three-axis orthogonal coordinate system defined as shown in FIG. That is, the Z-axis is a direction from the vertically lower side to the upper side, the X-axis is a direction from the back to the stomach of the golfer 7, and the Y-axis is parallel to the ground plane and goes from the ball hitting point to the target point. Direction.

<1-2-1. Measurement process>
In the measurement process, the golf club 4 with the sensor unit 1 is swung by the golfer 7. The golf club 4 swung in the measurement process is one of the two test clubs. These test clubs are different types of golf clubs. In the present embodiment, one test club is a professional golf club (hereinafter referred to as a professional model club), and the other is a golf club suitable for average users (hereinafter referred to as a golf club). Average model club). In the present embodiment, the professional model club is heavier than the average model club. Which test club is to be swung in the measurement process is determined based on the preference and experience of the golfer 7.

Subsequently, as described above golf club 4 grip acceleration a _x in the swing motion, a _y, a _z, grip angular velocity ω _x, ω _y, ω _z and grip geomagnetism m _x, m _y, m _z of the measurement data Is measured by the sensor unit 1. This measurement data is transmitted to the fitting device 2 via the communication device 10 of the sensor unit 1. On the other hand, on the fitting device 2 side, the acquisition unit 24 </ b> A receives this via the communication unit 25 and stores it in the storage unit 23. In this embodiment, at least time-series measurement data from the address to the impact is measured.

  Note that the golf club swing operation generally proceeds in the order of address, top, impact, and finish. The address means an initial state in which the head 41 of the golf club 4 is arranged near the ball, as shown in FIG. 5A, and the top means the golf club 4 from the address, as shown in FIG. Is taken back and the head 41 is swung up most. As shown in FIG. 5 (C), the impact means a state at the moment when the golf club 4 is swung down from the top and the head 41 collides with the ball, and the finish is as shown in FIG. 5 (D). It means a state in which the golf club 4 is swung forward after impact.

In the measurement process, it is preferable that the golf club 4 described above is tried a plurality of times, preferably five times or more. In this case, an average value of the measurement data can be calculated and used for subsequent calculations. Also, in order to remove abnormal values due to miss shots, measurement errors, etc., the standard deviation σ of the measurement data is calculated, and the measurement data of all trial hits are preferably within the average value ± 1.65σ, more preferably the average value ± 1. It is preferable to obtain measurement data that falls within 28σ. Then, in order to perform the check, the control unit 24 calculates the standard deviation σ of the measurement data. When the value of σ does not satisfy the above conditions, a message for requesting addition or re-measurement is displayed. You may make it display on the part 21. FIG. It should be noted that not the average value of the measurement data itself, but the average value of machining values calculated based on the measurement data (for example, arm output power P _{1 _AVE} , club input power P _{2 _AVE} and head speed V _h described later) May be calculated. Similarly, when calculating the average value of the processed values, it is possible to check the reliability of the data based on the standard deviation σ.

<1-2-2. First conversion step>
Hereinafter, the first conversion step for converting the measurement data of the xyz local coordinate system into the value of the XYZ global coordinate system will be described with reference to FIG. Specifically, first, the acquisition unit 24A performs grip accelerations a _x , a _y , a _z , grip angular velocities ω _x , ω _y , ω _z and grips in the xyz local coordinate system stored in the storage unit 23. geomagnetic m _x, m _y, reads the measurement data of the time series of m _z (step S11).

Next, based on the time-series measurement data in the xyz local coordinate system read in step S11, the grip behavior deriving unit 24B derives the times t _i , t _t , and t _a of the impact, the top, and the address. (Step S12). In this embodiment, the impact time t _i is first derived, the top time t _t is derived based on the impact time t _i , and the address time t _a is derived based on the top time t _t .

Specifically, the time when the increment of the grip angular velocity ω _x per sampling period Δt first exceeds the threshold of 300 deg / s is set as the temporary impact time. Then, the time at which the increment of the grip angular velocity ω _x per sampling period Δt exceeds 200 deg / s from the time when a predetermined time is passed from the time of the temporary impact to the time of the temporary impact is detected. The time t _i is set.

Next, the time before the impact time t _i and when the grip angular velocity ω _y is switched from negative to positive is specified as the top time t _t . The address time t _a is calculated according to the flowchart of FIG.

In subsequent step S13, the grip behavior deriving unit 24B calculates a posture matrix N (t) at time t from the address to the impact. Assume that the posture matrix is expressed by the following formula. The posture matrix N (t) is a matrix for converting the XYZ global coordinate system at time t to the xyz local coordinate system.

The meanings of the nine components of the posture matrix N (t) are as follows.
Component a: Cosine of the angle formed by the X axis of the global coordinate system and the x axis of the local coordinate system Component b: Cosine of the angle formed by the Y axis of the global coordinate system and the x axis of the local coordinate system Component c: Overall Cosine of angle formed by Z axis of coordinate system and x axis of local coordinate system Component d: Cosine of angle formed by X axis of global coordinate system and y axis of local coordinate system Component e: Y of global coordinate system Cosine of angle between axis and y axis of local coordinate system Component f: cosine of angle between Z axis of global coordinate system and y axis of local coordinate system Component g: X axis of global coordinate system and local Cosine of angle between z axis of coordinate system Component h: Cosine of angle between Y axis of global coordinate system and z axis of local coordinate system Component i: Z axis of global coordinate system and z of local coordinate system Here, the vector (a, b, c) represents a unit vector in the x-axis direction, and the vector (d, e, f) represents a single vector in the y-axis direction. Represents a vector, the vector (g, h, i) represents a unit vector in the z-axis direction.

Further, the attitude matrix N (t) can be expressed by the following equation according to the concept of Euler angles in the ZYZ system. Here, φ, θ, and ψ are rotation angles around the Z axis, the Y axis, and the Z axis.

In calculating the posture matrix N (t) to the impact from the address, first, the address of the time t _a at the posture matrix N (t _a) is calculated. Specifically, φ and θ at the time of address are calculated according to the following equations. Note that the following expression uses that the golf club 4 is stationary at the time of addressing and only the gravity in the vertical direction is detected by the acceleration sensor 11. The grip accelerations a _x , a _y , and a _z in the following expressions are values at the time of addressing.

Subsequently, ψ at the time of addressing is calculated according to the following equation.
However, the values of m _xi and my _{y in} the above formula are calculated according to the following formula. Further, the following grip geomagnetic m _x in the formula, m _y, m _z is the value at the address.

From the above, during the address phi, theta, [psi is grip acceleration a _x in the xyz local coordinate system, a _y, a _z and grip geomagnetism m _x, m _y, is calculated on the basis of the m _z. And these phi, theta, by substituting the value Expression 2 of [psi, address when the posture matrix N (t _a) is calculated.

Subsequently, the posture matrix N (t) from the address to the impact is calculated by updating the posture matrix N (t _a ) at the time of time at intervals of the sampling period Δt. More specifically, first, the attitude matrix N (t) is expressed by the following expression using four quaternion variables q ₁ , q ₂ , q ₃ , q ₄ (q ₄ is a scalar part).

Therefore, from Equations 1 and 7, the four quaternion variables q ₁ , q ₂ , q ₃ , and q ₄ can be calculated according to the following equations.

Now, the value of a~i that defines the address at the time of the attitude matrix N (t _a) is known. Therefore, according to the above formula, first, quaternion four variables q ₁ , q ₂ , q ₃ , and q ₄ at the time of address are calculated.

The quaternion q ′ after a lapse of a minute time from the time t is expressed by the following equation using the quaternion q at the time t.

The first-order differential equation representing the temporal change of the four quaternion variables q ₁ , q ₂ , q ₃ , and q ₄ is expressed by the following equation.

By using the equations (9) and (10), the quaternion at time t can be sequentially updated to the quaternion at the next time t + Δt. Here, the quaternion from the address to the impact is calculated. Then, by sequentially substituting the four quaternion variables q ₁ , q ₂ , q ₃ , and q ₄ from the address to the impact into the formula 7, the attitude matrix N (t) from the address to the impact is calculated. The

Next, in step S14, the grip behavior deriving unit 24B performs grip acceleration a _x , a _y , a _{z in} the xyz local coordinate system from the address to the impact based on the posture matrix N (t) from the address to the impact. In addition, the time series data of the grip angular velocities ω _x , ω _y , and ω _z is converted into time series data in the XYZ global coordinate system. The converted grip accelerations a _X , a _Y , a _Z and grip angular velocities ω _X , ω _Y , ω _Z are calculated according to the following equations.

In subsequent step S15, the grip behavior deriving unit 24B integrates the time series data of the grip accelerations a _X , a _Y , and a _Z , thereby grip speeds v _X , v _{Y in} the XYZ global coordinate system from the address to the impact. , V _Z is derived. At this time, it is preferable to perform offset so that the grip speeds v _X , v _Y , and v _Z from the address to the impact are 0 m / s at the top. For example, the offset at an arbitrary time t is calculated from (grip speeds v _X , v _Y , v _{Z at} the top time t _t ) × t / (t _{t from} the grip speeds v _X , v _Y , v _Z at the time _t. is performed by subtracting the -t _a).

<1-2-3. Second conversion step>
Hereinafter, the second conversion step for converting the behavior of the grip 42 in the XYZ global coordinate system calculated in the first conversion step into the behavior of the grip 42 in the swing plane P will be described. In the present embodiment, the swing plane P is defined as a plane that includes the origin of the XYZ global coordinate system and is parallel to the Y axis and the shaft 40 of the golf club 4 at the time of impact (see FIG. 8). In the second conversion step, the grip behavior deriving unit 24B projects the grip speeds v _X , v _Y , v _Z and the grip angular velocities ω _X , ω _Y , ω _Z in the XYZ global coordinate system into the swing plane P. v _pX , v _pY , v _pZ and grip angular velocities ω _pX , ω _pY , ω _pZ are calculated.

Specifically, based on the z-axis vector (g, h, i) included in the posture matrix N (t) representing the extending direction of the shaft 40, the golf player 7 is viewed from the front. E) Time series data of the inclination of the shaft 40 is calculated. Then, based on this time series data, the time when the shaft 40 is parallel to the Z axis when viewed from the positive direction of the X axis is specified, and this is set as the impact time t _i . Here, the impact time t _i does not always coincide with the impact time t _i already described. Subsequently, the inclination of the shaft 40 viewed from the negative Y-axis direction is calculated based on the z-axis vector (g, h, i) included in the posture matrix N (t _i ) at the time t _i of the impact. That is, an angle α ′ formed between the shaft 40 and the X axis viewed from the negative direction of the Y axis at the time of impact is calculated, and this is set as the swing plane angle.

When the swing plane angle α ′ is obtained, a projection transformation matrix A for projecting an arbitrary point in the XYZ global coordinate system onto the swing plane P can be calculated as follows. However, α = 90 ° −α ′.

Here, based on the above projective transformation matrix A, the grip speeds v _pX , v _pY , v _pZ and the grip angular velocities ω _pX , ω _pY , ω _pZ after the projective transformation from the address to the impact according to the following formula: Series data is calculated.

Note that the grip speed (v _pY , v _pZ ) obtained by the above calculation represents the grip speed (vector) in the swing plane P, and the grip angular speed ω _pX is an axis perpendicular to the swing plane P. It represents the angular velocity around. Here, the grip speed (scalar) in the swing plane P from the address to the impact is calculated according to the following equation.

Further, here, the inclination of the shaft 40 at the top in the swing plane P, which is necessary for the later calculation, is also calculated. Specifically, first, the z-axis vector (g, h, i) included in the top posture matrix N (t _t ) is projected into the swing plane P using the projective transformation matrix A according to the following equation. To do. Here, the projected vector is (g ′, h ′, i ′).

The vector (h ′, i ′) specified by the above expression is a vector representing the inclination of the shaft 40 at the top in the swing plane P. Therefore, the inclination β of the shaft 40 at the top in the swing plane P is calculated by substituting the above calculation results into the following equation.

<1-2-4. Shoulder behavior derivation process>
Hereinafter, a shoulder behavior derivation that derives a pseudo shoulder behavior in the swing plane P based on the grip behavior (grip speed V _GE and grip angular velocity ω _pX ) in the swing plane P while calculating FIG. The process will be described. In the present embodiment, the behavior of the golf club 4 is a double pendulum model in which the shoulder of the golfer 7 and the grip 42 (or the wrist of the golfer who holds the golf club 7) are nodes, and the arm of the golfer 7 and the golf club 4 are linked. Based on the analysis. However, the shoulder behavior is not directly measured, but is derived as a pseudo shoulder behavior based on the actually measured grip behavior. In the following, unless otherwise specified, the term “shoulder” simply means such a pseudo shoulder. The same applies to the pseudo “arm” defined as extending linearly between the pseudo shoulder and the grip 42 (wrist).

In specifying the shoulder behavior from the grip behavior, the double pendulum model according to the present embodiment is based on the following (1) to (5). FIG. 10 is a diagram conceptually illustrating the following preconditions.
(1) On the swing plane P, the grip 42 (wrist) moves circularly around the shoulder.
(2) On the swing plane P, the distance (radius) R between the shoulder and the grip 42 is constant.
(3) The shoulder does not move (but rotates) during the swing motion.
(4) On the swing plane P, the angle between the top arm and the golf club 4 is 90 °.
(5) The arm at the time of impact faces the lower side of the Z axis when viewed from the positive direction of the X axis.

Under the above assumption, the shoulder behavior deriving unit 24C calculates the movement distance D of the grip 42 from the top to the impact in the swing plane P (step S21). The moving distance D is derived by integrating the grip speed V _GE from the top to the impact.

  Subsequently, the shoulder behavior deriving unit 24C calculates the arm rotation angle γ from the top to the impact in the swing plane P (step S22). The rotation angle γ is calculated based on the inclination β of the shaft 40 at the top calculated in the second conversion step. Next, the shoulder behavior deriving unit 24C calculates the radius R = D / γ (step S23).

Then, the shoulder behavior deriving unit 24C calculates an angular velocity (an angular velocity of the arm) ω ₁ around the shoulder from the top to the impact in the swing plane P as the shoulder behavior according to the following equation. That is, the arm angular velocity ω ₁ is a value reflecting the measured grip velocity V _GE .
ω ₁ = V _GE / R

<1-2-5. Index calculation process>
Hereinafter, an index calculation step for calculating a swing index for determining the optimum swing MI based on the behavior of the grip 42 and the behavior of the shoulder will be described with reference to FIG. The swing index is a characteristic amount that characterizes the swing motion by the golfer 7. In the present embodiment, arm output power P _{1 _AVE} , club input power P _{2 _AVE,} and head speed V _h described later are used as swing indices. Calculated.

Specifically, first, in step S31, the shoulder behavior deriving unit 24C integrates the angular velocity ω ₁ of the arm from the top to the impact, and calculates the rotational angle θ ₁ of the arm from the top to the impact. At this time, it is preferable to use trapezoidal integration. The rotation angle θ ₁ is defined as shown in FIG. 12, and the plane of FIG. 12 is equal to the swing plane P. In the following, the analysis proceeds based on the new XY coordinate system in the swing plane P shown in FIG. The X axis of the new XY coordinate system in the swing plane P is equal to the Y axis of the XYZ global coordinate system described above, and the Y axis of the new XY coordinate system is the Z axis of the XYZ global coordinate system within the swing plane P. Is the axis projected onto

Further, the shoulder behavior deriving unit 24C differentiates the angular velocity ω ₁ of the arm from the top to the impact, and calculates the angular acceleration ω ₁ ′ from the top to the impact. Next, the shoulder behavior deriving unit 24C calculates the position (X ₁ , Y ₁ ), the velocity (V _X1 , V _Y1 ) and the acceleration (A _X1 , A _Y1 ) of the center of gravity of the arm from the top to the impact. These values are calculated by substituting the calculation results described above into the following equations.

  Where r is the distance from the shoulder to the center of gravity of the arm. In the present embodiment, it is assumed that the center of gravity of the arm is at the center of the arm. Therefore, R = 2r.

Next, in step S <b> 32, the grip behavior deriving unit 24 </ b> B performs the same calculation as that in step S <b> 31 for the periphery of the grip 42. That is, the grip angular velocity ω _pX from the top to the impact = the angular velocity ω ₂ of the golf club 4 around the grip 42 is integrated, and the rotation angle θ ₂ of the golf club 4 (shaft 40) around the grip 42 from the top to the impact is calculated. To do. Also at this time, it is preferable to use trapezoidal integration, and the rotation angle θ ₂ is defined as shown in FIG.

Subsequently, the grip behavior deriving unit 24B differentiates the angular velocity ω ₂ of the golf club 4 from the top to the impact, and calculates the angular acceleration ω ₂ ′ from the top to the impact. Next, the grip behavior deriving unit 24B calculates the position (X ₂ , Y ₂ ), speed (V _X2 , V _Y2 ), and acceleration (A _X2 , A _Y2 ) of the golf club 4 from the top to the impact. . These values are calculated by substituting the calculation results described above into the following equations.

  However, L is the distance from the grip 42 to the center of gravity of the golf club 4. The value of L is a specification of the golf club 4 and is set in advance.

Next, in step S33, the index calculation unit 24D calculates the restraining force R ₁ = (R _X1 , R _Y1 ) generated on the shoulder from the top to the impact by substituting the above calculation result into the following equation. In addition, the restraining force R ₂ = (R _X2 , R _Y2 ) generated in the grip 42 from the top to the impact is calculated. The following formula is based on the balance of forces in the translational direction. However, m ₁ is the mass of the arm, and in this embodiment, the mass m ₁ of the arm is determined in advance as appropriate. For example, before starting the analysis, the weight of the golfer 7 is input, and the weight of the arm is automatically calculated by multiplying the input weight by a predetermined coefficient. m ₂ is the mass of the golf club, and g is the acceleration of gravity. Further, m ₂ is the specification of the golf club 4 and is determined in advance.

In the subsequent step S34, the index calculation unit 24D calculates the torque _Tg1 around the center of gravity of the arm from the top to the impact and the torque _Tg2 around the center of gravity of the golf club by substituting the above calculation results into the following equations. To do.
However, I ₁ is the moment of inertia around the center of gravity of the arm, and I ₂ is the moment of inertia around the center of gravity of the golf club 4. In this embodiment, the moment of inertia I ₁ of the arm of the center of gravity around the center of gravity of the arm under the assumption that the center of the arm is calculated as ^{_{I 1 = m 1 r 2/}} 3. I ₂ is the specification of the golf club 4 and is determined in advance.

In subsequent step S35, the index calculating unit 24D calculates the arm power (power) E ₁ ′ from the top to the impact based on the above-described calculation result. Specifically, E ₁ 'is the velocity vector of the shoulder and v _s, the velocity vector of the grip 42 as v _g, expressed according to the following equation. Further, v _s and v _g can be calculated by first-order differentiation of the shoulder position vector d _s and the grip 42 position vector d _g = d _s + (2X ₁ , 2Y ₁ ), respectively.

In this embodiment, since the shoulder does not move, v _s = (0, 0), and the arm power E ₁ ′ is calculated according to the following equation. The index calculation unit 24D calculates the arm power E ₁ ′ from the top to the impact by substituting the calculation result described above into the following equation.

By the way, in the golf swing, in order to accelerate the tip (head 41) of the golf club 4 most, it is required to first accelerate the arm sufficiently, and then stop the movement of the arm to give the golf club 4 momentum. It is thought that. The acceleration degree of the arm here can be replaced with a physical index called power (arm output power) P ₁ output by the arm, and the momentum applied to the golf club 4 is the power input to the golf club 4 (club it can be replaced with a physical indication that the input power) P _2. The arm output power P ₁ corresponds to the second and third term parts on the right side of Expression 22 representing the arm power E ₁ ′. Further, the club input power P ₂ corresponds to the first term part on the right side in the equation (22). That is, the arm output power P ₁ and the club input power P ₂ can be expressed as follows. In step S35, the index calculation unit 24D calculates the arm output power P ₁ and the club input power P ₂ from the top to the impact in addition to the arm power E ₁ ′.

The work rate E ₂ ′ exhibited by the golf club 4 during the swing motion can be expressed as the following equation. That is, club input power P ₂ = R ₂ v _g ^T becomes the bridge, energy is transferred from the arm to the golf club 4.

In subsequent step S36, the index calculation unit 24D identifies the time t _c a work rate of the arm with subsequent top E ₁ 'turns from positive to negative, the workload of the arm from time t _t of the top to the time t _c E ₁ is calculated. The work E ₁ of the arm is calculated by integrating the work E ₁ ′ of the arm in the interval from time t t to _{t c} (see FIG. 13). The work amount E ₁ can be considered as an index representing the work amount (energy) exerted by the arm between the times t t to _{t c} , and in this sense, the work amount E ₁ is called arm energy during the swing operation. Can do. Also, index calculation unit 24D calculates a time _t t ~t average work rate _{E AVE = E 1 / t c} -t t exerted by the arms during _c. The average power E _AVE is arm energy that is averaged or consumed per unit time during the swing motion.

Also, index calculation unit 24D, the arm output power P ₁ from the time t _t of top integrates the arm output power P ₁ in the interval up to time t _m taking the maximum value, the integrated value D ₁ of the integration interval (t _c− t _m ), the average arm output power P _{1 _AVE} during the swing motion is calculated. Incidentally, the integrated value D ₁ is the amount of work the arm makes a golfer during a swing operation can be an indicator of the arm output power. Similarly, the index calculation unit 24D, the club input power P ₂ from the time t _t of top integrates the club input power P ₂ in the interval until time t _n to the maximum value, the integrated value D ₂ integration interval ( By dividing by t _c -t _n ), an average club input power P _{2 _AVE} during the swing operation is calculated. Incidentally, the integrated value D ₂ is the amount of work that is against the golf club 4 during a swing operation can be an indicator of the club input power. The integration interval shown here is merely an example, and for example, an interval from time t _{t to t c} can be set as appropriate.

In subsequent step S37, the index calculation unit 24D calculates a cock release timing t _r during the swing operation. The present inventors, through experimentation, head speed V _h at impact as the swing indicator, cook release timing t _r during the swing operation, and is correlated with the arm energy E ₁ or the average work rate E _AVE I discovered that. Therefore, here, in order to calculate the head speed V _h at impact, cock release timing t _r is calculated. In the present embodiment, the cock release timing t _r is the time t _t ~t section arms work rate at up to _c E ₁ 'is the time when the maximum is identified as a cook release timing t _r (see FIG. 13) .

In subsequent step S38, the index calculation unit 24D calculates the head speed V _h at the time of impact based on the cock release timing _tr and the arm energy E _AVE . Specifically, the head speed V _h at the time of impact is calculated according to the following formula. Note that k ₁ , k ₂ , and k ₃ are constants obtained by multiple regression analysis from the results of many experiments performed in advance, and are values that are stored in the storage unit 23 in advance. Thus, the index calculation process ends.
V _h = k ₁ · E _AVE + k ₂ · _tr + k ₃

Through the above processing, the arm output power P _{1 _AVE} , the club input power P _{2 _AVE,} and the head speed V _h are calculated as swing indexes for determining the optimum swing MI.

<1-2-6. Optimal swing MI determination process>
Hereinafter, the flow of the optimal swing MI determination process for determining the optimal swing MI (the swing inertia moment of the golf club 4 suitable for a golfer) will be described with reference to FIG.

The swing moment of inertia is the moment of inertia around the shoulder during a swing, and can be defined according to the following equation, for example. I _S is the swing moment of inertia.
I _S = I ₂ + m ₂ (R + L) ² + I ₁ + m ₁ (R / 2) ²

In addition, about each golfer 7, even if the golf club 4 changes, the weight of an arm is the same. Therefore, in this embodiment, for the sake of simplicity, the swing inertia moment is calculated according to the following equation, omitting the inertia moment corresponding to the rotation of the arm.
I _S = I ₂ + m ₂ (R + L) ²

Furthermore, in this embodiment, the swing inertia moment is calculated with the arm length R = 60 cm (constant). However, the value of the arm length R calculated in step S23 can be substituted for R in the above formula. Incidentally, m ₂ , I ₂ , and L, which are parameters for determining I _S, are the specifications of the golf club 4. Therefore, the swing moment of inertia in the present embodiment is also a specification of the golf club 4.

  First, in step S40, the determination unit 24E determines the type of the test club that has been tried in the measurement process. If the professional model club has been trial-struck, the process proceeds to step S41, and if the average model club has been trial-struck, the process proceeds to step S51. Which test club has been tried is determined based on information input by the user via the input unit 22.

Note that the type of the test club is determined in step S40 because the area where the swing index is distributed differs depending on the type of the test club. More specifically, the inventors have 21 golfers who normally use professional model golf clubs (hereinafter referred to as professional model users) and golfers who normally use average model golf clubs (hereinafter referred to as averages). When the model users were given a trial shot of 22 professional model clubs and average model clubs to calculate the swing index, the results shown in FIGS. 15 and 16 were obtained. Note that the swing indices calculated in this experiment are the arm output power P _{1 _AVE} and the club input power P _{2 _AVE} , and specific values were calculated according to the same process as described above. The inventors have found from the results shown in FIGS. 15 and 16 that the space indicating the swing index is roughly divided into a pro model area and an average model area. Note that the pro model region is a region where the swing index at the time of the swing motion by the professional model user is distributed, and the average model region is the region where the swing index at the time of the swing motion by the average model user is distributed. As can be seen by comparing FIG. 15 and FIG. 16, the pro model region is a region in which the arm output power P _{1 _AVE} and the club input power P _{2 _AVE} are both larger than the average model region. However, these numerical values may differ depending on swing conditions such as the type of test club. In this experiment, a driver of SRIXON (registered trademark) Z-525 (shaft is Miyazaki Kosuma Blue 6 S-Flex, the weight of the golf club is 314 g, and the balance is D3) manufactured by Dunlop Sports Co., Ltd. is used as a professional model club. XXIO (registered trademark) 8 manufactured by Dunlop Sports Co., Ltd. (shaft is MP-800 R-Flex, golf club weight is 272 g, balance is D3) was used as the average model club. .

Next, step S41 and subsequent steps S42 to S44 will be described. Step S41~S44, depending on the size of the arm output power P ₁ _ _AVE and club input power P ₂ _ _AVE, the range of the optimum swing MI (hereinafter, the optimum swing MI band) is a step of determining. Here, as the values of P _{1 _AVE} and P _{2 _AVE} are larger, the optimum swing MI band is set to a larger value stepwise.

Specifically, in step S41, determination unit 24E was calculated by the index calculation step _{(P 1 _ AVE, P 2} _ AVE) is a point represented by, P ₁ _ _AVE -P ₂ shown in FIG. 15 It is determined whether it is above the straight line L1 in the _{_AVE} plane, that is, whether it belongs to the area A1 in FIG. When the professional condition 1 is satisfied, it is determined that 5623 kg · cm ² or more is the optimum swing MI band. On the other hand, if the professional condition 1 is not satisfied in step S41, the process proceeds to step S42. In step S42, determination unit 24E was calculated by the index calculation step _{(P 1 _ AVE, P 2} _ AVE) is a point represented by the straight line in P ₁ _ _AVE -P ₂ _ _AVE plane shown in FIG. 15 It is determined whether it is above L2 and below the straight line L1, that is, whether it belongs to the area A2 in FIG. 15 (hereinafter referred to as professional condition 2). If professional condition 2 is satisfied, it is determined that 5540-5623 kg · cm ² is the optimum swing MI band. On the other hand, if the professional condition 2 is not satisfied in step S42, the process proceeds to step S43. At step S43, the determining section 24E was calculated by the index calculation step _{(P 1 _ AVE, P 2} _ AVE) is a point represented by the straight line in P ₁ _ _AVE -P ₂ _ _AVE plane shown in FIG. 15 It is determined whether it is above L3 and below the straight line L2, that is, whether it belongs to the area A3 in FIG. 15 (hereinafter referred to as professional condition 3). When professional condition 3 is satisfied, it is determined that 5480 to 5540 kg · cm ² is the optimum swing M band I. On the other hand, if the professional condition 3 is not satisfied in step S43, the process proceeds to step S44. At step S44, the determining section 24E was calculated by the index calculation step _{(P 1 _ AVE, P 2} _ AVE) is a point represented by the straight line in P ₁ _ _AVE -P ₂ _ _AVE plane shown in FIG. 15 It is determined whether it is above L4 and below the straight line L3, that is, whether it belongs to the area A4 in FIG. 15 (hereinafter referred to as professional condition 4). When the professional condition 4 is satisfied, it is determined that 5400 to 5480 kg · cm ² is the optimum swing MI band. On the other hand, when the professional condition 4 is not satisfied in step S44, that is, the point represented by (P ₁ _ _AVE , P ₂ _ _AVE ) calculated in the index calculation step is P ₁ _ _AVE −P shown in FIG. _If it is below the straight line L4 in the _{2_AVE} plane and belongs to the region A5 in FIG. 15, it is determined that 5400 kg · cm ² or less is the optimum swing MI band.

On the other hand, step S51 and subsequent steps S52 and S53 are steps for determining an optimum swing MI band in accordance with the arm output power P _{1 _AVE} , the club input power P _{2 _AVE,} and the head speed V _h. is there. Here, as the values of P _{1 _AVE} , P _{2 _AVE,} and V _h are larger, the optimum swing MI band is set to a larger value stepwise.

Specifically, determining unit 24E, in step S51, is calculated by the index calculation step _{(P 1 _ AVE, P 2} _ AVE) is a point represented by, P ₁ _ _AVE -P ₂ shown in FIG. 16 It is determined whether it is above the straight line L5 in the _{_AVE} plane, that is, whether it belongs to the area B1 in FIG. 16 (hereinafter, average condition 1). When the average condition 1 is satisfied, it is determined that 5300 kg · cm ² or more is the optimum swing MI band. On the other hand, when the average condition 1 is not satisfied in step S51, the process proceeds to step S52. In step S52, determination unit 24E was calculated by the index calculation step _{(P 1 _ AVE, P 2} _ AVE) is a point represented by the straight line in P ₁ _ _AVE -P ₂ _ _AVE plane shown in FIG. 16 It is determined whether it is above L6 and below the straight line L5, that is, whether it belongs to the region B2 in FIG. 16 (hereinafter, average condition 2). When the average condition 2 is satisfied, it is determined that 5200 to 5300 kg · cm ² is the optimum swing MI band. On the other hand, when the average condition 2 is not satisfied in step S52, the process proceeds to step S53. In step S53, the determination unit 24E determines whether or not the head speed V _h calculated in the index calculation step is greater than 35.5 m / s (average condition 3). When the average condition 3 is satisfied, it is determined that 5200-5300 kg · cm ² is the optimum swing MI band. On the other hand, when the average condition 3 is not satisfied in step S53, that is, the point represented by (P ₁ _ _AVE , P ₂ _ _AVE ) calculated in the index calculation step is more than the straight line L6 shown in FIG. If it is on the lower side and belongs to the region B3 in FIG. 15, it is determined that 5200 kg · cm ² or less is the optimum swing MI band.

The above steps S41 to S44 and steps S51 to S53 are based on the following knowledge. That is, in the above-described experiment described with reference to FIGS. 15 and 16, the head speed V _h and the optimum swing MI that maximizes the flight distance were also calculated. The head speed V _h was calculated according to the same process as described above. On the other hand, the optimal swing MI, to swing the golf club of the various swing moment of inertia I _s to the golfer, to identify the swing moment of inertia I _s of the golf club which gives the maximum distance, which was the best swing MI. More specifically, the professional model user, swing moment of inertia I _s swing the five types of golf club of ^{5650kg · cm 2, 5610kg · cm} 2, 5520kg · cm 2, 5440kg · cm 2, 5360kg · cm 2 I let you. On the other hand, the average model user, swing moment of inertia I _s was shown swing the three types of golf club of ^{5330kg · cm 2, 5230kg · cm} 2, 5130kg · cm 2. 15 and 16 also show the values of the head speed V _h [m / s] and the optimum swing MI obtained by this experiment.

As shown in FIGS. 15 and 16, it can be seen from the above experiment that the optimum swing MI increases as the arm output power P _{1 _AVE} and the club input power P _{2 _AVE} both increase. As a result, the present inventors can divide the arm output power P _{1 _AVE} −club input power P _{2 _AVE} space (professional model region) into regions as shown in FIG. It has been found that the areas A1 to A5 can be defined. Further, by dividing the arm output power P _{1 _AVE} −club input power P _{2 _AVE} −head speed V _h space (average model region) into regions as shown in FIG. 16, the region corresponding to the optimum swing MI band It has been discovered that B1-B3 can be defined. However, for simplicity, in FIG. 16, the axis representing the head speed V _h is omitted, the arm output power P ₁ _ _AVE - Club input power P ₂ _ _AVE plane is shown. That is, steps S41~S44 described above, depending on whether the point indicating the arm output power P ₁ _ _AVE and club input power P ₂ _ _AVE is plotted in which region of the P ₁ _ _AVE -P ₂ _ _AVE space Thus, the optimum swing MI band is determined. On the other hand, step S51~S53 are arms output power P ₁ _ _AVE, point indicating the club input power P ₂ _ _AVE and head speed V _h is, in any region in the _{P 1 _ AVE -P 2 _ AVE} -V h space This is a step of determining the optimum swing MI band depending on whether the plot is made. Threshold values used for the determinations in steps S41 to S44 and steps S51 to S53, in other words, information for specifying the boundary lines L1 to L6 of the divided areas A1 to A5 and B1 to B3 shown in FIGS. Each test club model is arranged and stored as correspondence data 28 in the storage unit 23. That is, the correspondence data 28 is data that defines the correspondence between the magnitudes of P _{1 _AVE} , P _{2 _AVE,} and V _h and the optimum swing MI band. The boundary lines L1 to L4 are substantially parallel to each other, and the boundary lines L5 and L6 are also substantially parallel to each other. The boundary lines L1 to L6 are all straight lines having a negative slope in the P _{1 _AVE-} P _{2 _AVE} plane. In steps S41 to S44 and steps S51 to S53, the correspondence data 28 in the storage unit 23 is referred to, and the above determination is performed. In FIG. 2, the correspondence relationship data 28 is shown as data different from the fitting program 3, but may be incorporated in the program 3.

By the way, in the average model area, when the points indicating the arm output power P _{1 _AVE} and the club input power P _{2 _AVE} belong to the area B3, it depends on whether or not the head speed V _h is greater than 35.5 m / s. It can be distributed to different optimum swing MI bands. This is because, as shown in the experimental results shown in FIG. 16, in these regions, the optimum swing MI is different depending on whether V _h > 35.5 m / s.

When the optimal swing MI band is determined by the above steps, the determination unit 24E specifies a golf club belonging to the optimal swing MI band from among various golf clubs whose swing MI is known. Note that the storage unit 23 in advance, in association with the information identifying the number of golf clubs (manufacturer, model number, etc.), to calculate the swing moment of inertia of the golf club I _s, or swing moment of inertia I _s Stores information indicating specifications including necessary values. The display control unit 24F displays the optimum swing MI band on the display unit 21 together with information indicating the type of the specified golf club. Thereby, the user can know the type of golf club suitable for the golfer 7 and can know the optimum swing MI band.

<2. Second Embodiment>
In FIG. 17, the whole structure of the fitting system 120 which concerns on 2nd Embodiment is shown. The fitting system 120 is common in many respects to the fitting system 100 according to the first embodiment. Therefore, in the following, for the sake of simplicity, the difference between the second embodiment and the first embodiment will be mainly described, and the same reference numerals are given to the same components as those in the first embodiment, and the description thereof will be omitted.

  The difference between the second embodiment and the first embodiment is that an optimum grip end MI decision step is mainly executed instead of the optimum swing MI decision step. More specifically, in the first embodiment, the optimal swing MI is determined as the optimal swing ease index, but in the second embodiment, instead of this, a grip end inertia moment (hereinafter referred to as an optimal grip) suitable for a golfer is used. End MI) is determined.

The grip end moment of inertia is the moment of inertia around the grip end, and is calculated according to the following equation in this embodiment. _IG is the grip end moment of inertia.
I _G = I ₂ + m ₂ L ²
Incidentally, m _2, I _2, L is a parameter which determines the I _G is the specifications of the golf club 4. Therefore, the grip end moment of inertia in the present embodiment is also a specification of the golf club 4.

  As shown in FIG. 17, the fitting system 120 includes a fitting device 102 instead of the fitting device 2. The fitting device 102 has the same hardware configuration as the fitting device 2, but the fitting device 102 is installed with a fitting program 103 instead of the fitting program 3. Therefore, the control unit 24 reads and executes the fitting program 103 in the storage unit 23 to virtually acquire the acquisition unit 24A, the grip behavior deriving unit 24B, the shoulder behavior deriving unit 24C, the index calculating unit 24D, and the display control unit. In addition to operating as 24F, it can operate as the determination unit 124E. The determination unit 124E is a virtual unit that executes an optimal grip end MI determination step that is a difference from the first embodiment. In addition, correspondence data 128 is stored in the storage unit 23 of the fitting apparatus 102 in place of the correspondence data 28 so that the optimum grip end MI determination step can be executed. The correspondence data 128 is data indicating conditions for determining the optimum grip end MI.

  In the second embodiment, as in the first embodiment, the measurement process, the first conversion process, the second conversion process, the shoulder behavior derivation process, and the index calculation process are sequentially performed, and then the optimum grip end MI determination process is performed. The Below, the optimal grip end MI determination process which is a difference with 1st Embodiment is demonstrated.

<2-1. Optimal grip end MI determination process>
As can be seen by comparing FIGS. 14 and 18, the optimum grip end MI determination step is the same as the optimum swing MI determination step except that the optimum swing ease index that is finally distributed is different. Accordingly, although detailed description is omitted, as shown in FIG. 18, in the optimum grip end MI determination step, the arm output power P _{1 _AVE} , the club input power P _{2 _AVE,} and the head speed V _h are determined. Thus, the range of the optimum grip end MI (hereinafter referred to as the optimum grip end MI band) is determined. Further, as the values of P _{1 _AVE} , P _{2 _AVE,} and V _h are larger, the optimum grip end MI band is set to a larger value stepwise.

As is apparent from the comparison of the definition formulas of the grip end inertia moment I _G and the swing inertia moment I _S , they can be converted to each other if the arm length R is known, and are approximately proportional. FIG. 25 is a graph plotting the relationship between I _S and I _G of various golf clubs. 19 and 20 are diagrams in which the values of the optimum swing MI and the optimum swing MI band in FIGS. 15 and 16 are converted into the optimum grip end MI and the optimum grip end MI band. From the above, it can be seen that the optimum grip end MI increases as the arm output power P _{1 _AVE} and the club input power P _{2 _AVE} both increase. Therefore, the arm output power P _{1 _AVE} −club input power P _{2 _AVE} space (pro model area) can be divided into areas A1 to A5 indicating the optimum grip end MI band as shown in FIG. Further, the arm output power P _{1 _AVE} −club input power P _{2 _AVE} −head speed V _h space (average model region) is divided into regions B1 to B3 indicating the optimum grip end MI band as shown in FIG. be able to. However, for the sake of simplicity, in FIG. 20, the axis representing the head speed V _h is omitted, and the arm output power P _{1 _AVE} −club input power P _{2 _AVE} plane is shown. That is, steps S61~S64 optimum grip end MI determining step, a point showing the arm output power P ₁ _ _AVE and club input power P ₂ _ _AVE is plotted in which region of the P _{1_AVE} -P ₂ _ _AVE space Accordingly, the optimum grip end MI band is determined. On the other hand, step S71~S73 are arms output power P ₁ _ _AVE, point indicating the club input power P ₂ _ _AVE and head speed V _h is, in any region in the _{P 1 _ AVE -P 2 _ AVE} -V h space The optimum grip end MI band is determined depending on whether the plot is plotted. It should be noted that the threshold values used in the determinations in steps S61 to S64 and steps S71 to S73 of the present embodiment, in other words, the boundary lines L1 to L6 of the divided areas A1 to A5 and B1 to B3 shown in FIGS. Information to be identified is organized for each model of the test club and stored in the storage unit 23 as correspondence data 128. That is, the correspondence relationship data 128 is data that defines the correspondence relationship between the sizes of P _{1 _AVE} , P _{2 _AVE,} and V _h and the optimum grip end MI band. In steps S61 to S64 and steps S71 to S73, the correspondence data 128 in the storage unit 23 is referred to, and the above determination is performed. In FIG. 17, the correspondence relationship data 128 is shown as data different from the fitting program 103, but may be incorporated in the program 103.

When the optimum grip end MI band is determined by the above steps, the determination unit 124E specifies a golf club belonging to the optimum grip end MI band from among various golf clubs whose grip end inertia moments I _G are known. . In the storage unit 23, the grip end inertia moment I _G or the grip end inertia moment I _G of the golf club is calculated in advance in association with information (manufacturer, model number, etc.) specifying a large number of golf clubs. Stores information indicating specifications including values necessary for the operation. The display control unit 24F displays the optimum grip end MI band on the display unit 21 together with information indicating the type of the specified golf club. Thus, the user can know the type of golf club suitable for the golfer 7 and can know the optimum grip end MI band.

<3. Third Embodiment>
FIG. 21 shows the overall configuration of the fitting system 130 according to the third embodiment. The fitting system 130 is common in many respects to the fitting systems 100 and 120 according to the first and second embodiments. Therefore, in the following, for the sake of simplicity, the difference between the third embodiment and the first embodiment will be mainly described, and the same components as those in the first and second embodiments will be denoted by the same reference numerals and described. Is omitted.

  The difference between the third embodiment and the first embodiment is that an optimum club weight determining step is mainly executed instead of the optimum swing MI determining step. More specifically, in the first embodiment, the optimum swing MI is determined as an optimum swinging ease index, but in the third embodiment, instead of this, the weight of the golf club 4 suitable for a golfer (optimum club weight). ) Is determined.

  As shown in FIG. 21, the fitting system 130 includes a fitting device 202 instead of the fitting device 2. The fitting device 202 has the same hardware configuration as the fitting device 2, but in the fitting device 202, a fitting program 203 is installed instead of the fitting program 3. Therefore, the control unit 24 reads and executes the fitting program 203 in the storage unit 23 to virtually acquire the acquisition unit 24A, the grip behavior deriving unit 24B, the shoulder behavior deriving unit 24C, the index calculating unit 24D, and the display control unit. In addition to operating as 24F, it can operate as the determination unit 224E. The determining unit 224E is a virtual unit that executes an optimum club weight determining step that is a difference from the first embodiment. In addition, correspondence data 228 is stored in the storage unit 23 of the fitting device 202 in place of the correspondence data 28 so that the optimum club weight determination process can be executed. The correspondence relationship data 228 is data indicating conditions for determining the optimum club weight.

  In the third embodiment, as in the first embodiment, the measurement process, the first conversion process, the second conversion process, the shoulder behavior derivation process, and the index calculation process are sequentially performed, and then the optimum club weight determination process is performed. . Below, the optimal club weight determination process which is a difference with 1st Embodiment is demonstrated.

<3-1. Optimal club weight determination process>
As can be seen by comparing FIG. 14 and FIG. 22, the optimum club weight determination step is the same as the optimum swing MI determination step except that the optimum swing ease index to be finally distributed is different. Accordingly, although detailed description is omitted, as shown in FIG. 22, in the optimum club weight determination step, the arm output power P _{1 _AVE} , the club input power P _{2 _AVE,} and the head speed V _h are determined. The optimum club weight range (hereinafter, the optimum club weight range) is determined. Further, as the values of P _{1 _AVE} , P _{2 _AVE,} and V _h are larger, the optimum club weight band is set to a larger value step by step.

As is apparent from the definition formula I _S of the swing moment of inertia, I _S and m ₂ can be converted to each other if the arm length R is known, and are approximately proportional. FIG. 26 is a graph plotting the relationship between m ₂ and I _S of various golf clubs. 23 and 24 are diagrams in which the values of the optimum swing MI and the optimum swing MI band in FIGS. 15 and 16 are converted into the optimum club weight and the optimum club weight band. From the above, it can be seen that the optimum club weight increases as the arm output power P _{1 _AVE} and the club input power P _{2 _AVE} both increase. Thus, the arm output power P ₁ _ _AVE - Club input power P ₂ _ _AVE space (pro model region) can be divided into areas A1~A5 showing the optimum club weight range as shown in FIG. 23. Further, the arm output power P _{1 _AVE} −club input power P _{2 _AVE} −head speed V _h space (average model region) is divided into regions B1 to B3 indicating the optimum club weight zone as shown in FIG. Can do. However, for the sake of simplicity, in FIG. 24, the axis representing the head speed V _h is omitted, and the arm output power P _{1 _AVE} −club input power P _{2 _AVE} plane is shown. That is, steps S81~S84 optimum club weight determining step, a point showing the arm output power P ₁ _ _AVE and club input power P ₂ _ _AVE is plotted in which region of the P ₁ _ _AVE -P ₂ _ _AVE space Depending on whether or not, the optimum club weight zone is determined. On the other hand, step S91~S93 are arms output power P ₁ _ _AVE, point indicating the club input power P ₂ _ _AVE and head speed V _h is, in any region in the _{P 1 _ AVE -P 2 _ AVE} -V h space It is a step of determining the optimum club weight band depending on whether it is plotted. Note that the threshold values used for the determinations in steps S81 to S84 and steps S91 to S93 of the present embodiment, in other words, the boundary lines L1 to L6 of the divided areas A1 to A5 and B1 to B3 shown in FIGS. Information to be identified is organized for each model of the test club and stored in the storage unit 23 as correspondence data 228. That is, the correspondence data 228 is data that defines the correspondence between the magnitudes of P _{1 _AVE} , P _{2 _AVE,} and V _h and the optimum club weight band. In steps S81 to S84 and steps S91 to S93, the correspondence data 228 in the storage unit 23 is referred to, and the above determination is performed. In FIG. 21, the correspondence relationship data 228 is shown as data different from the fitting program 203, but may be incorporated in the program 203.

When the optimum club weight band is determined by the above steps, the determination unit 224E specifies a golf club belonging to the optimum club weight band from various golf clubs whose weight m ₂ is known. In the storage unit 23, information indicating specifications including the weight m _{2 of the} golf club is stored in advance in association with information (manufacturer, model number, etc.) specifying a large number of golf clubs. The display control unit 24F displays the optimum club weight band on the display unit 21 together with information indicating the type of the specified golf club. Thus, the user can know the type of golf club suitable for the golfer 7 and can know the optimum club weight zone.

  15, 16, 19, 20, 23, and 24 show the results of an experiment in which 21 professional model users and 22 average model users actually tried a test club as described above. It is plotted. As for the professional model user, the optimal swing MI is determined to be the optimal swing MI band determined in the above-described optimal swing MI determination step in 20 of the 21 data except the one with the F mark. As a result of belonging. The same applies to the optimum grip end MI and the optimum club weight. That is, it was confirmed that fitting was possible with a correct answer rate of 95% or more. As for the average model user, the optimal swing MI is determined to be the optimal swing MI band determined in the above-described optimal swing MI determination process in 21 of the 22 data except the one with the F mark. As a result of belonging. The same applies to the optimum grip end MI and the optimum club weight. That is, it was confirmed that fitting was possible with a correct answer rate of 95% or more.

<4. Fourth Embodiment>
FIG. 27 shows the overall configuration of the fitting system 140 according to the fourth embodiment. The fitting system 140 is common in many respects to the fitting systems 100, 120, and 130 according to the first to third embodiments. Therefore, in the following, for the sake of simplicity, the difference between the fourth embodiment and the first embodiment will be mainly described, and the same components as those in the first to third embodiments will be described with the same reference numerals. Is omitted.

  FIG. 28 is a flowchart illustrating a flow of the swing motion analysis process according to the fourth embodiment. As apparent from a comparison between FIG. 4 and FIG. 28, the difference in the analysis processing between the fourth embodiment and the first embodiment is that the optimum shaft weight determining step (S6) is mainly used instead of the optimum swing MI determining step (S6). S306) is executed. More specifically, in the optimal swing MI determining step (S6) according to the first embodiment, the optimal swing MI is finally determined, but in the optimal shaft weight determining step (S306) according to the fourth embodiment, Finally, the weight (optimum shaft weight) of the shaft 40 of the golf club 4 suitable for the golfer is determined. That is, in the first to third embodiments, the optimal swingability index is determined, but in the fourth embodiment, the optimal shaft is used as the optimal characteristic index that represents the characteristics of a specific part of the golf club 4 suitable for the golfer. The weight is determined.

  As shown in FIG. 27, the fitting system 140 includes a fitting device 302 instead of the fitting device 2. The fitting device 302 has the same hardware configuration as the fitting device 2, but in the fitting device 302, a fitting program 303 is installed instead of the fitting program 3. Therefore, the control unit 24 reads and executes the fitting program 303 in the storage unit 23 to virtually acquire the acquisition unit 24A, the grip behavior deriving unit 24B, the shoulder behavior deriving unit 24C, the index calculating unit 24D, and the display control unit. In addition to operating as 24F, it can operate as the determination unit 324E. The determination unit 324E is a virtual unit that executes an optimum shaft weight determination process that is a difference from the first embodiment. In addition, correspondence data 328 is stored in the storage unit 23 of the fitting device 302 in place of the correspondence data 28 so that the optimum shaft weight determination step can be executed. The correspondence data 328 is data indicating conditions for determining the optimum shaft weight.

  In the fourth embodiment, as in the first embodiment, the measurement process, the first conversion process, the second conversion process, the shoulder behavior derivation process, and the index calculation process are sequentially performed, and then the optimum shaft weight determination process is performed. . Below, the optimal shaft weight determination process which is a difference with 1st Embodiment is demonstrated.

<4-1. Optimal shaft weight determination process>
The optimal shaft weight determination step, determination unit 324E, in accordance with the magnitude of the swing indicator (arm output power P ₁ _ _AVE, club input power P ₂ _ _AVE and head speed V _h), the optimum shaft weight range (hereinafter , The optimum shaft weight band) is determined. At this time, as the values of P ₁ _ _AVE , P ₂ _ _AVE and V _h are larger, the optimum shaft weight band is set to a larger value stepwise. Specifically, the optimum shaft weight determination process proceeds according to the flowchart shown in FIG.

In step S101, determination unit 324E, the arm output power P ₁ _ _AVE, depending on the size of the club input power P ₂ _ _AVE and head speed V _h, determines the optimum swing optimum swing MI is easy indicator. The optimal swing MI can be calculated according to the flowchart shown in FIG. 14 as in the first embodiment, but is calculated according to the following multiple regression equation in the present embodiment.
(Optimum swing MI) = e ₁ · P _{1 _AVE} + e ₂ · P _{2 _AVE} + e ₃ · V _h + e ₄

The multiple regression equation is a multiple regression equation in which the arm output power P _{1 — AVE} , the club input power P _{2 — AVE} and the head speed V _h are explanatory variables, and the optimal swing MI is an objective variable. The coefficients e _{1 to} e ₄ are obtained by experimentally obtaining a large number of data sets of variables P ₁ _ _AVE , P ₂ _ _AVE, V _h and the optimal swing MI in advance, and performing multiple regression analysis based on these data sets. And stored in the storage unit 23 as correspondence data 328. That is, the correspondence data 328 is data that defines the correspondence between the magnitudes of P _{1 _AVE} , P _{2 _AVE,} and V _h and the optimum swing MI. The multiple regression equation, that is, the correspondence data 328 can be prepared for each model of the test club. In this case, as in the first to third embodiments, the accuracy of analysis can be improved. In FIG. 27, the correspondence relationship data 328 is shown as data different from the fitting program 303, but may be incorporated in the program 303.

In subsequent step S102, the determination unit 324E determines the optimum shaft weight band according to the magnitude of the optimum swing MI. Specifically, the optimum swing MI is converted into the optimum shaft weight band according to Table 1 below. The following Table 1 is also included in the correspondence data 328.

  When the optimum shaft weight band is determined by the above steps, the determination unit 324E executes step S103. In step S103, the shaft 40 belonging to the optimum shaft weight band is specified from various shafts whose weights are known. In the storage unit 23, information indicating the characteristics of the shaft 40 is stored in advance in association with information (manufacturer, model number, etc.) specifying a large number of shafts 40. The information indicating the characteristics of the shaft 40 includes weight and rigidity (tone, flex, etc.). The display control unit 24F displays the optimum shaft weight band on the display unit 21 together with information indicating the type and characteristics of the identified shaft 40. Thus, the user can know the type and characteristics of the shaft 40 suitable for the golfer 7 and can know the optimum shaft weight band.

  In addition, the present inventors attached shafts of various weights to SRIXON (registered trademark) Z-745 manufactured by Dunlop Sports Co., Ltd. and made 37 golf testers hit these golf clubs. Then, for each tester, the weight of the shaft that maximizes the flight distance was determined and set as the optimum shaft weight by experiment. For each of the 37 testers, the optimum shaft weight band was derived by the same method as the optimum shaft weight determination step described above. When these results were compared, in 33 out of 37 people, the optimum shaft weight by experiment belonged to the optimum shaft weight zone determined in the optimum swing MI determination step. That is, it was confirmed that fitting was possible with a correct answer rate of about 90%.

<5. Modification>
As mentioned above, although several embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible unless it deviates from the meaning. For example, the following changes can be made. Moreover, the gist of the following modifications can be combined as appropriate.

<5-1>
In the above-described embodiment, the sensor unit 1 including the acceleration sensor, the angular velocity sensor, and the geomagnetic sensor is used as the measurement device that measures the swing motion of the golfer 7, but the measurement device may have other configurations. . For example, the geomagnetic sensor can be omitted. In this case, the measurement data can be converted from the xyz local coordinate system to the XYZ global coordinate system by a statistical method. In addition, since such a method is a well-known technique (refer to Unexamined-Japanese-Patent No. 2013-56074 if needed), detailed description is abbreviate | omitted here. Alternatively, a three-dimensional measurement camera can be used as a measurement device. Since a method of measuring the behavior of a golfer, a golf club, or a golf ball with a three-dimensional measurement camera is also known, detailed description thereof is omitted here. If a 3D measurement camera is used, the process of converting the measurement data from the xyz local coordinate system to the XYZ global coordinate system can be omitted, and the grip behavior in the XYZ global coordinate system can be measured directly. can do.

<5-2>
The head speed V _h can be calculated by other methods than the statistical method based on the multiple regression equation described above. For example, you may calculate geometrically according to the following formula | equation. However, L _club is the length of the golf club which is the spec of the golf club.
Position vector (d _hX , d _hY ) of the head at the tip of the shaft 40
d _hX = 2X ₁ + L _club cos θ ₂
d _hY = 2Y ₁ + L _club sin θ ₂
Speed vector (V _hX , V _hY ) of the head at the tip of the shaft 40
V _hX = 2V _X1 -L _club ω ₂ sin θ ₂
V _hY = 2V _Y1 + L _club ω ₂ cos θ ₂
V _h = sqrt (V _hX ² + V _hY ² )

<5-3>
The optimum swing MI determination process, the optimal grip end MI determination process, and the optimal club weight determination process can be executed by the user himself, not the fitting devices 2, 102, 202. That is, the calculated swing index is displayed on the display unit 21 after the index calculation process is completed. Then, based on the correspondence data 28, 128, 228 as shown in FIGS. 15, 16, 19, 20, 23, and 24, the user himself / herself has the optimum swing MI band, optimum grip end MI band and optimum The club weight zone may be determined. At this time, if the correspondence data 28, 128, 228 is displayed on the display unit 21 or a paper medium on which the correspondence data 28, 128, 228 is printed is prepared, the user's judgment becomes easy. The same applies to the optimum shaft weight determination step.

<5-4>
In the above embodiment, the arm output power P ₁ _ _AVE , the club input power P _{2 _AVE} and the head speed V _h are used in combination as the swing index. However, the present invention is not limited to this example. only ₁ _ _AVE, may be used only _{P 2 _ AVE, (P 1} _ AVE, V h), (P 2 _ AVE, V h), as _{(P 1 _ AVE, P 2} _ AVE) A combination of two indices may be used. In addition, various other swing indexes such as optimal club weight, optimal swing MI, and optimal grip end MI, and other various swing indexes having a certain relationship (correlation) with the optimal characteristic index are set as P _{1 _AVE} and / or It can be used in combination with P _{2 _AVE} . For example, average power E _AVE , E _1, etc. can be used as a swing index.

In the above embodiment, the pro model area is divided without using the head speed V _h and the average model area is divided using the head speed V _h , but the pro model area is divided using the head speed V _h. it may be also possible to divide the average model area without using the head speed V _h.

<5-5>
In the above embodiment, the calculation of the optimal swing MI, the optimal grip end MI, and the optimal club weight is exemplified as the optimal swing ease index. However, an optimum value may be calculated for various other indexes representing the ease of swinging the golf club and used as the optimum swing ease index. For example, the inertia moment I ₂ around the center of gravity of the golf club is also correlated with the swing index, and the optimum value of the inertia moment I ₂ around the center of gravity of the golf club may be calculated as the optimum swing ease index. In the above embodiment, the optimum swing MI, the optimum grip end MI, and the optimum club weight are calculated as the optimum swing ease indices. However, a plurality of optimum swing ease indices are calculated and all these optimum swing ease indices are calculated. The fitting may be performed based on the index. For example, all of the optimum swing MI, the optimum grip end MI, and the optimum club weight may be calculated, and a golf club meeting these three conditions may be searched from the database.

<5-6>
In the above embodiment, an example of the shoulder behavior derivation process based on the above (1) to (5) has been described. Can do.

In the shoulder behavior deriving step according to this modification, among the above assumptions (1) to (5), (4) and (5) are omitted, and only (1) to (3) are assumed. Specifically, the shoulder behavior deriving unit 24C approximates the trajectory of the grip 42 in the swing plane P obtained in the second conversion step to an arc (circle) (see FIG. 30). The center of the arc (circle) is the shoulder position P _s = (P _sX , P _sY ), and the average distance from the center of the arc (circle) to the track of the grip 42 is the arm length (shoulder And the grip 42). In this case, in the second conversion step preceding the shoulder behavior deriving process, it is assumed that the track of the grip 42 in the swing plane P is calculated by the grip behavior deriving unit 24B. For example, the trajectory of the grip 42 integrates the grip speed (v _pY , v _pZ ) in the swing plane P, and a point A _i = (X _i , Y _i ) (i = 1, 2) on the grip 42 trajectory. ,...) Can be calculated. In addition, i here is a data number along a time series.

An example of a method for deriving an approximate circle (arc) of the grip 42 will be described below. First, consider three arbitrary points on the track of the grip 42, for example, A _i , A _{i + 30} , and A _{i + 60} . At this time, since the center of the circumscribed circle of any triangle is the intersection of the perpendicular bisectors of the three sides of the triangle, a triangle having A _i , A _{i + 30} , and A _{i + 60} as vertices is considered. (See FIG. 31), the following equation (24) and thus the equation (25) are established.

Then, the following Expression 26 is created from the plurality of Expressions 25 for various i, and a pseudo inverse matrix is derived. Thereby, the center P _s = (P _sX , P _sY ) of the approximate circle (arc) of the track of the grip 42 can be derived.

Subsequently, the shoulder behavior deriving unit 24C _determines the _distance from the center P _s = (P _sX , P _sY ) of the approximate circle (arc) to each point A _i = (X _i , Y _i ) on the track of the grip 42. An average value is calculated and set as arm length R. Then, based on the arm length R, the shoulder behavior deriving unit 24C calculates an angular velocity around the shoulder from the top to the impact in the swing plane P (an angular velocity of the arm) ω ₁ = V _GE / R.

  FIG. 32A shows a double pendulum model from the top to the impact reproduced by the method according to the embodiment, and FIG. 32B shows a double pendulum model from the top to the impact reproduced by the method according to this modification. Show. As is obvious from comparison of these figures, in this modification, the assumption (4) is omitted, so that the angle between the arm at the top and the golf club 4 is evaluated. You can appreciate the deep. Further, by omitting the premise (5), the arm angle at the time of impact is evaluated, so handfast / handrate can be evaluated.

<5-7>
In the fourth embodiment, after determining the optimum swing MI based on the swing index, the optimum characteristic index (optimum shaft weight) is determined based on the optimum swing MI. However, the optimum characteristic index can be directly calculated according to the size of the swing index. Specifically, for example, a multiple regression equation having the swing index as an explanatory variable and the optimum characteristic index as an objective variable can be calculated and stored in advance as the correspondence data 328. In this case, the optimum characteristic index can be derived by substituting the swing index derived in the index calculation step into the multiple regression equation. Alternatively, as in FIG. 15 and FIG. 16 of the first embodiment, the P _{1 _AVE−} P _{2 _AVE} (−V _h ) plane is divided into regions, and the region corresponding to the optimum characteristic index is defined ( 33), the definition information can be stored in advance as correspondence data 328. In this case, the optimum characteristic index can be derived according to which region the swing index derived in the index calculation step belongs.

<5-8>
In the fourth embodiment, the optimal swing MI is used as the optimal swingability index for determining the optimal characteristic index (optimum shaft weight), but another optimal swingability index, for example, the optimal grip end MI, An optimum club weight can also be used.

<5-9>
In the fourth embodiment, the optimum shaft weight is derived as the optimum characteristic index. Instead of or in addition to this, an index that represents the characteristics of a portion other than the shaft 40 suitable for the golfer, for example, a grip 42 suitable for the golfer. The weight of can also be derived. In addition, as a characteristic of a specific part of the golf club 4, a characteristic other than weight, for example, a moment of inertia can be derived.

1 Sensor unit (measuring device)
2,102,202 Fitting device 3,103,203 Fitting program 4 Golf club 7 Golfer 24A Acquisition unit 24B Grip behavior deriving unit 24C Shoulder behavior deriving unit 24D Index calculation unit (calculation unit)
24E, 124E, 224E determination unit 41 head 42 grip

Claims (14)

A fitting device for determining an optimal swingability index that is a golf club swingability index suitable for a golfer,
An acquisition unit for acquiring a measurement value obtained by measuring a swing motion of the test club by the golfer with a measurement device;
Based on the measurement value, a swing index including at least one of an index indicating the power output by the golfer's arm during the swing operation and an index indicating the power input to the test club during the swing operation is calculated. A calculation unit;
A determination unit that determines the optimal swingability index according to the size of the swing index;
Fitting device. The calculation unit calculates a plurality of types of the swing index,
The determining unit determines the optimal swingability index according to the size of the plurality of types of swing indexes.
The fitting device according to claim 1. The swing index includes an index indicating the power output by the golfer's arm during the swing operation, and an index indicating the power input to the test club during the swing operation.
The fitting device according to claim 2. The swing index includes a head speed during the swing operation,
The determining unit determines the optimal swingability index according to the size of the head speed.
The fitting apparatus in any one of Claim 1 to 3. The determination unit determines the optimum swing ease index to a larger value as the swing index is larger or smaller.
The fitting apparatus in any one of Claim 1 to 4. For each type of the test club, a storage unit for storing correspondence data that defines a correspondence relationship between the swing index size and the optimum swing ease index size is further provided.
The determining unit determines the optimal swingability index by referring to the correspondence data in the storage unit according to the type of the test club.
The fitting apparatus in any one of Claim 1 to 5. The swingability index includes at least one of a moment of inertia around the golfer's shoulder, a moment of inertia of the golf club, and a weight of the golf club.
The fitting apparatus in any one of Claim 1 to 6. A fitting method for determining an optimal swingability index, which is a golf club swingability index suitable for a golfer,
Measuring the swing movement of the test club by the golfer with a measuring device;
Based on the measurement value, a swing index including at least one of an index indicating the power output by the golfer's arm during the swing operation and an index indicating the power input to the test club during the swing operation is calculated. Steps,
Determining the optimal swingability index according to the size of the swing index,
Fitting method. A fitting program for determining an optimal swingability index that is a golf club swingability index suitable for a golfer,
Obtaining a measurement value obtained by measuring the swing motion of the test club by the golfer with a measuring device;
Based on the measurement value, a swing index including at least one of an index indicating the power output by the golfer's arm during the swing operation and an index indicating the power input to the test club during the swing operation is calculated. Steps,
Causing the computer to execute a step of determining the optimal swingability index according to the size of the swing index;
Fitting program. A fitting device for determining an optimum characteristic index representing a characteristic of a specific part of a golf club suitable for a golfer,
An acquisition unit for acquiring a measurement value obtained by measuring a swing motion of the test club by the golfer with a measurement device;
Based on the measurement value, a swing index including at least one of an index indicating the power output by the golfer's arm during the swing operation and an index indicating the power input to the test club during the swing operation is calculated. A calculation unit;
A determination unit that determines the optimum characteristic index according to the size of the swing index;
Fitting device. The specific part is a shaft or a grip,
The fitting apparatus according to claim 10. The determining unit determines an optimal swingability index that is a swingability index of the golf club suitable for the golfer according to the size of the swing index, and according to the size of the optimal swingability index. And determining the optimum characteristic index,
The fitting device according to claim 10 or 11. The determination unit substitutes the swing index calculated by the calculation unit into a predetermined regression equation using the swing index as an explanatory variable and the optimal swing ease index as a target variable, thereby determining the optimal swing ease. Calculate metrics,
The fitting device according to claim 12. The determination unit calculates the optimum characteristic index by substituting the swing index calculated by the calculation unit into a predetermined regression equation using the swing index as an explanatory variable and the optimal characteristic index as a target variable. ,
The fitting device according to claim 10 or 11.