JP6809100B2 - Golf swing analyzer - Google Patents

Description

The present invention relates to a golf swing analyzer.

Conventionally, a device that analyzes a swing motion based on measurement data obtained by measuring a golf club swing motion by a golfer with a measuring device has been known (Patent Document 1 and the like). In Patent Document 1, a golf club that is normally used by a golfer is swung, the swing motion at this time is analyzed to calculate the trajectory of the grip end of the golf club, and this is used for swing motion in various golf clubs. By applying it, a method of simulating the behavior of the head of a golf club that is not actually swinging, the deformation of the shaft, and the like is disclosed.

Japanese Unexamined Patent Publication No. 2011-168650

By the way, if the golf club changes, the golfer's swing also changes. For example, swinging a heavy golf club can reduce the swing speed, and conversely swinging a light golf club can increase the swing speed. In addition, the trajectory of the swing may change depending on the golf club that swings. In this regard, in the method of Patent Document 1, the simulation is performed on the assumption that the locus of the grip end is always constant regardless of the golf club. Therefore, even if the swing motion of a golf club that is not actually swinging can be simulated, the change in the swing according to the golf club is not taken into consideration, and further improvement is desired in terms of analysis accuracy.

An object of the present invention is to provide a golf swing analysis device, method and program capable of accurately estimating the swing motion of a golf club that is not actually swinging.

The golf swing analysis device according to the first aspect is a golf swing analysis device that analyzes the swing motion of a golf club, and includes an acquisition unit, a determination unit, and a simulation unit. The acquisition unit acquires measurement data obtained by measuring the swing motion of the reference club by the golfer with a measuring device. Based on the measurement data, the determination unit derives the optimum club characteristics representing the club characteristics suitable for the golfer, and determines the optimum club, which is a golf club that matches the optimum club characteristics. The simulation unit calculates the optimum club swing data representing the swing motion of the optimum club by the golfer, and obtains the optimum club swing data and the physical properties of a virtual club which is a golf club in which the golfer does not actually swing. Based on this, virtual club swing data representing the swing motion of the virtual club by the golfer is estimated.

The golf swing analysis device according to the second aspect is the golf swing analysis device according to the first aspect, and in the simulation unit, when the virtual club has smaller club characteristics than the optimum club, the golfer's swing is said. The virtual club swing data is estimated on the assumption that it is constant regardless of the physical properties of the virtual club.

The golf swing analysis device according to the third viewpoint is a golf swing analysis device according to the first viewpoint or the second viewpoint, and the simulation unit is the golfer when the virtual club has larger club characteristics than the optimum club. The virtual club swing data is estimated on the assumption that the force exerted during the swing operation is constant regardless of the physical properties of the virtual club.

The golf swing analysis device according to the fourth viewpoint is a golf swing analysis device according to any one of the first to third viewpoints, and the simulation unit compares the club characteristics of the optimum club and the reference club. The virtual club swing data is estimated according to an algorithm selected according to the result of the comparison.

The golf swing analysis device according to the fifth viewpoint is a golf swing analysis device according to any one of the first to fourth viewpoints, and the virtual club swing data is exhibited by the golfer during the swing operation of the virtual club. The torque to be applied is included.

The golf swing analysis device according to the sixth viewpoint is a golf swing analysis device according to any one of the first to fifth viewpoints, and the virtual club swing data includes the swing trajectory during the swing operation of the virtual club and the swing trajectory. At least one of the head speeds is included.

The golf swing analysis device according to the seventh viewpoint is a golf swing analysis device according to any one of the first to sixth viewpoints, and the determination unit is based on the measurement data when the reference club swings. The swing index of the above is derived, and the optimum club characteristic is derived according to the swing index.

The golf swing analysis device according to the eighth aspect is the golf swing analysis device according to the seventh aspect, and the swing index includes the power output by the golfer's arm, the power input to the reference club, and the golfer. It includes at least one of the energy exerted by the golfer, the torque exerted by the golfer, and the head speed immediately before impact.

The golf swing analysis device according to the ninth viewpoint is a golf swing analysis device according to any one of the first to eighth viewpoints, and the optimum club characteristic is an index of ease of swinging a golf club suitable for the golfer. is there.

The golf swing analysis device according to the tenth viewpoint is the golf swing analysis device according to the ninth viewpoint, and the optimum club characteristics include a club weight suitable for the golfer, a shaft weight, and a moment of inertia around the shoulder of the golfer. , At least one of the moments of inertia of the golf club is included.

The golf swing analysis method according to the eleventh aspect is a golf swing analysis method for analyzing the swing motion of a golf club, and includes the following steps.
(1) A step of acquiring measurement data obtained by measuring the swing motion of a reference club by a golfer with a measuring device.
(2) A step of deriving an optimum club characteristic representing a club characteristic suitable for the golfer based on the measurement data, and determining an optimum club which is a golf club matching the optimum club characteristic.
(3) Optimal club swing data representing the swing motion of the optimum club by the golfer is calculated, and based on the optimum club swing data and the physical properties of a virtual club which is a golf club in which the golfer does not actually swing. , A step of estimating virtual club swing data representing the swing motion of the virtual club by the golfer.

The golf swing analysis program according to the twelfth aspect is a golf swing analysis program that analyzes the swing motion of a golf club, and causes a computer to execute the following steps.
(1) A step of acquiring measurement data obtained by measuring the swing motion of a reference club by a golfer with a measuring device.
(2) A step of deriving an optimum club characteristic representing a club characteristic suitable for the golfer based on the measurement data, and determining an optimum club which is a golf club matching the optimum club characteristic.
(3) Optimal club swing data representing the swing motion of the optimum club by the golfer is calculated, and based on the optimum club swing data and the physical properties of a virtual club which is a golf club in which the golfer does not actually swing. , A step of estimating virtual club swing data representing the swing motion of the virtual club by the golfer.

According to the first aspect, the optimum club suitable for the golfer is determined based on the measurement data obtained by measuring the swing motion of the reference club by the golfer. Then, the swing motion of the virtual club by the golfer is estimated based on the swing motion of the optimum club by the golfer and the physical characteristics of the virtual club which is a golf club in which the golfer does not actually swing. That is, in estimating the swing motion of the virtual club, the swing motion by the optimum club is taken into consideration, so that the change in the swing according to the golf club is taken into consideration. As a result, the swing motion of the virtual club can be estimated accurately.

The figure which shows the golf swing analysis system provided with the golf swing analysis apparatus which concerns on one Embodiment of this invention. Functional block diagram of the golf swing analysis system. The figure explaining the xyz local coordinate system with respect to the grip of a golf club. (A) The figure which shows the address state. (B) The figure which shows the top state. (C) The figure which shows the impact state. (D) The figure which shows the finish state. A flowchart showing the flow of golf swing analysis processing. A flowchart showing the flow of the optimum club determination process included in the golf swing analysis process. The figure explaining the swing plane. The figure which conceptually explains the double pendulum model. The figure which explains the shoulder behavior derivation process conceptually. A flowchart showing the flow of the swing index calculation process. Another figure that conceptually illustrates the double pendulum model. A flowchart showing the flow of the optimum club characteristic derivation process. The figure which shows the arm output power-club input power plane divided into the region corresponding to a plurality of optimum shaft weight bands. The figure which shows the relationship between the swing ease index and the head speed. The figure which shows the relationship between the swing ease index and the exertion power by a golfer. The figure which shows the relationship of the index when the reference club has a smaller swingability index than the optimum club. The figure which shows the relationship of the index when the reference club has a larger swingability index than the optimum club.

Hereinafter, the embodiment of the present invention will be described with reference to the drawings.

<1. Outline configuration of golf swing analysis system>
1 and 2 show the overall configuration of the golf swing analysis system 100 including the golf swing analysis device 2 according to the present embodiment. The golf swing analysis device 2 analyzes the swing motion based on the measurement data obtained by measuring the swing motion of the golf club 4 by the golfer 7. The result of the analysis is used for various purposes such as fitting of a golf club 4 for selecting a golf club 4 suitable for the golfer 7, improvement of the form of the golfer 7, development of golf equipment, and the like. In the present embodiment, the swing motion is measured by the inertial sensor unit 1, and the golf swing analysis device 2 constitutes the golf swing analysis system 100 together with the inertial sensor unit 1. Hereinafter, the configuration of the inertial sensor unit 1 and the golf swing analysis device 2 will be described, and then the flow of the golf swing analysis process will be described.

<1-1. Inertia sensor unit configuration>
As shown in FIGS. 1 and 3, the inertial sensor unit 1 is attached to the end 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 is composed of 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 inertial sensor unit 1 is compact and lightweight so as not to interfere with the swing operation. Further, the inertial sensor unit 1 is removable from the golf club 4 and can be attached to the outside of the golf club 4.

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

The acceleration sensor 11, the angular velocity sensor 12, and the geomagnetic sensor 13 measure the acceleration, angular velocity, and geomagnetism of the grip 42 in the xyz local coordinate system with respect to the grip 42, respectively. More specifically, the acceleration sensor 11, x-axis, the acceleration a _x of the y-axis and z-axis direction, a _y, measures the a _z. The angular velocity sensor 12 measures the angular velocities ω _x , ω _y , and ω _z around the x-axis, y-axis, and z-axis. Geomagnetic sensor 13 measures the x-axis, y-axis and z-axis direction terrestrial magnetism m _x, m _y, a m _z. These measurement data are acquired as time-series data having a predetermined sampling period Δt. The xyz local coordinate system is a 3-axis Cartesian coordinate system defined as shown in FIG. That is, the z-axis coincides with the extending direction of the shaft 40, and the direction from the head 41 to the grip 42 is the z-axis positive direction. The x-axis is oriented as close as possible to the toe-heel direction of the head 41, and the y-axis is oriented as close as possible to the normal direction of the face surface of the head 41.

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

<1-2. Configuration of golf swing analysis device>
The configuration of the golf swing analysis device 2 will be described with reference to FIG. The golf swing analysis device 2 is manufactured by installing a golf swing analysis program 3 stored in a computer-readable recording medium 20 such as a CD-ROM or a USB memory on a general-purpose personal computer from the recording medium 20. To. The golf swing analysis program 3 is software for analyzing the swing motion based on the measurement data sent from the inertial sensor unit 1 and displaying the analysis result. The golf swing analysis program 3 causes the golf swing analysis device 2 to execute an operation described later.

The golf swing analysis device 2 includes a display unit 21, an input unit 22, a storage unit 23, a control unit 24, and a communication unit 25. The units 21 to 25 are connected to each other via the bus line 26 and can communicate with each other. In the present embodiment, the display unit 21 is composed of a liquid crystal display or the like, and displays information described later to the user. The term "user" as used herein is a general term for golfers 7 themselves, their instructors, developers of golf equipment, and the like who need the results of analysis. Further, the input unit 22 can be composed of a mouse, a keyboard, a touch panel, etc., and receives an operation from the user on the golf swing analysis device 2. The communication unit 25 is a communication interface that enables communication between the golf swing analysis device 2 and the external device, and receives measurement data from the inertial sensor unit 1.

The storage unit 23 is composed of a non-volatile storage device such as a hard disk. In addition to storing the golf swing analysis program 3 in the storage unit 23, measurement data sent from the inertial sensor unit 1 is stored. Further, the correspondence data 28, the head database (DB) 27, and the shaft database (DB) 29 are stored in the storage unit 23. In the head DB 27, information indicating specifications of a large number of heads 41 is stored in association with information for specifying the type of the head 41. The information indicating the specifications of the head 41 includes information indicating the manufacturer, model number, weight of the head 41, position of the center of gravity, moment of inertia, and the like. In the shaft DB 29, information indicating specifications of a large number of shafts 40 is stored in association with information for specifying the type of the shaft 40. The information indicating the specifications of the shaft 40 includes information indicating the manufacturer, model number, weight, length, position of the center of gravity, flex, torque, tone, and the like of the shaft 40. The correspondence data 28 will be described later.

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

<2. Golf swing analysis processing>
Next, the golf swing analysis process executed by the golf swing analysis system 100 will be described with reference to FIG. In the golf swing analysis process, first, the inertial sensor unit 1 measures the swing motion of the golf club 4 by the golfer 7 (step S1; measurement step). Hereinafter, the golf club 4 used in the measurement process is referred to as a reference club.

Next, based on the measurement data, the optimum club characteristics, which are the characteristics of the golf club 4 (hereinafter referred to as the optimum club) suitable for the golfer 7, are derived, and the optimum club, which is the golf club 4 that matches the optimum club characteristics, is determined. (Step S2; optimum club determination step).

Subsequently, the reference club and the optimum club are compared, and which is the golf club having the larger swingability index is determined (step S3; comparison step). Then, according to the algorithm selected according to the result of the comparison, swing data representing the swing motion of the optimum club by the golfer 7 (hereinafter referred to as the optimum club swing data) is estimated, and based on the optimum club swing data, the swing data is estimated. Swing data (hereinafter referred to as virtual club swing data) representing the swing motion of the virtual club by the golfer 7 is estimated (steps S4 and S5; simulation step). Step S4 is executed when it is determined that the reference club is a golf club having a smaller swingability index, and step S5 is determined to be a golf club whose swingability index is smaller than that of the optimum club. Will be executed if The virtual club is a golf club 4 in which the golfer 7 does not actually swing.

After that, the result of the above analysis is displayed on the display unit 21 (step S6; output step). Hereinafter, the details of steps S1 to S6 will be described in order.

<2-1. Measurement process (S1)>
In the measurement step (S1), the golfer 7 swings the reference club, which is the golf club 4 with the inertial sensor unit 1 described above. At this time, the acceleration a _x in the swing motion of the reference clubs, a _y, a _z, the angular velocity ω _x, ω _y, ω _z and geomagnetism m _x, m _y, measurement data relating to m _z are collected by inertial sensor unit 1 Will be done. This measurement data is transmitted to the golf swing analysis device 2 via the communication device 10. On the other hand, on the golf swing analysis device 2 side, the acquisition unit 24A receives the measurement data via the communication unit 25 and stores the measurement data in the storage unit 23. In this embodiment, at least time-series measurement data from the address to the impact is measured. In the measurement step, it is preferable that the reference club is tried a plurality of times, preferably about 2 to 5 times. In this case, the average value of various values calculated based on the measurement data can be calculated, and by using this average value in the subsequent calculation, the variation in the analysis result can be reduced.

The golf swing generally proceeds in the order of address, top, impact, and finish. The address means a stationary state in which the head 41 of the golf club 4 is arranged near the ball as shown in FIG. 4 (A), and the top means the golf club 4 from the address as shown in FIG. 4 (B). It means a state in which the head 41 is swung up most after taking back. As shown in FIG. 4 (C), the impact means the 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. 4 (D). It means a state in which the golf club 4 is swung forward after the impact.

<2-2. Optimal club determination process (S2)>
The optimum club determination step (S2) is a step of deriving the optimum club characteristics and determining the optimum club as described above, and proceeds as shown in FIG. The optimum club characteristic of the present embodiment is the weight of the shaft 40 suitable for a golfer (hereinafter referred to as the optimum shaft weight).

First, the measurement data regarding the accelerations a _x , a _y , a _z and the angular velocities ω _x , ω _y , ω _z in the xyz local coordinate system acquired in the measurement process are the accelerations a _X , a _Y in the XYZ overall coordinate system. , A _Z and angular velocities ω _X , ω _Y , ω _Z (step S21; first conversion step). The XYZ overall coordinate system is a 3-axis Cartesian coordinate system defined as shown in FIG. That is, the Z-axis is the direction from vertically downward to upward, the X-axis is the direction from the back to the belly of the golfer 7, and the Y-axis is parallel to the ground plane from the ball hitting point to the target point. The direction. Subsequently, the behavior of the grip 42 in the XYZ global coordinate system is converted into the behavior of the grip 42 in the swing plane P (described later) (step S22; second conversion step).

Next, based on the behavior of the grip 42 in the swing plane P, the pseudo shoulder behavior of the golfer 7 in the swing plane P is derived (step S23; shoulder behavior derivation step). Subsequently, based on the behavior of the grip 42 and the pseudo shoulder behavior in the swing plane P, the swing index at the time of the swing operation of the reference club (in this embodiment, the arm output power P ₁ _ _AVE and the club described later). The input power P ₂ _ _AVE ) is calculated (step S24; swing index calculation step).

After that, the optimum club characteristics (in the present embodiment, the optimum shaft weight) are derived based on the swing index (step S25; optimum club characteristic derivation step), and the optimum club matching the optimum club characteristics is selected (step S26). Optimal club selection process). Hereinafter, the details of steps S21 to 26 will be described in order.

<2-2-1. First conversion step (S21)>
In the first conversion step (S21), the behavior of the grip 42 in the xyz local coordinate system is converted into the behavior of the grip in the XYZ overall coordinate system. Specifically, determining unit 24B is, acceleration a _x stored in the storage unit 23, when a _y, a _z, the angular velocity ω _x, ω _y, ω _z and geomagnetism m _x, m _y, m _z Read the series data, and based on these time series data, convert the acceleration a _x , a _y , a _z and the angular velocity ω _x , ω _y , ω _z from the address to the impact into the time series data in the XYZ global coordinate system. Convert. Hereinafter, the acceleration and the angular velocity in the XYZ overall coordinate system after conversion are referred to as accelerations a _X , a _Y , a _Z and angular velocities ω _X , ω _Y , ω _Z. There are various known methods for converting values from the local coordinate system to the global coordinate system. Therefore, although detailed description is omitted here, if necessary, the methods described in JP-A-2016-2429, JP-A-2016-2430, and the like by the same applicants can be followed. Further, in the first conversion step, the determination unit 24B derives the grip speeds v _X , v _Y , v _Z in the XYZ overall coordinate system by integrating the time series data of the accelerations a _X , a _Y , and a _Z. To do.

<2-2-2. Second conversion step (S22)>
In the second conversion step (S22), the determination unit 24B converts the behavior of the grip 42 in the XYZ global coordinate system calculated in the first conversion step (S21) into the behavior of the grip 42 in the swing plane P. To do. In this embodiment, the swing plane P includes the origin of the XYZ global coordinate system and is defined as a plane parallel to the Y axis and the shaft 40 at impact (see FIG. 7). The determination unit 24B calculates the grip speed (v _pY , v _pZ ) _obtained by projecting the grip speeds v _X , v _Y , v _Z in the XYZ global coordinate system from the address to the impact into the swing plane P, and also calculates the following grip speeds (v _pY , v _pZ ). According to the equation, the grip velocity V _GE (scalar) in the swing plane P from the address to the impact is calculated.

Further, the determination unit 24B calculates the trajectory of the grip 42 in the swing plane P by integrating the grip speeds (v _pY , v _pZ ). Further, the determination unit 24B calculates the grip angular velocity ω _pX around the axis orthogonal to the swing plane P. The specific calculation method of the second conversion step can be appropriately selected, but if necessary, it is described in JP-A-2016-2429, JP-A-2016-2430, etc. by the same applicants. You can follow the method of.

<2-2-3. Shoulder behavior derivation process (S23)>
Hereinafter, a shoulder behavior deriving step (S23) for deriving a pseudo shoulder behavior in the swing plane P based on the grip behavior in the swing plane P will be described. In the present embodiment, the behavior of the golf club 4 is a double pendulum model in which the shoulder and grip 42 of the golfer 7 (or the wrist of the golfer who holds the golf club 4) are the nodes, and the arm of the golfer 7 and the golf club 4 are linked. It is analyzed based on (see FIG. 8). However, the shoulder behavior is not directly measured, but is derived as a pseudo shoulder behavior based on the measured grip behavior. In the following, unless otherwise specified, the term "shoulder" may mean 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 identifying the behavior of the shoulder from the behavior of the grip, the double pendulum model is premised on the following (1) to (3). FIG. 8 is a diagram conceptually explaining the following preconditions.
(1) On the swing plane P, the grip 42 (wrist) makes a circular motion 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 operation.

Under the above premise, the determination unit 24B approximates the trajectory of the grip 42 in the swing plane P obtained in the second conversion step (S22) to an arc (circle) (see FIG. 9). Then, the center of the arc (circle) is derived as the shoulder position P _s = (P _sX , P _sY ), and the average distance from the center of the arc (circle) to the trajectory of the grip 42 is the arm length. (Distance between shoulder and grip 42) Let R be. Next, the determination unit 24B calculates the angular velocity (angular velocity of the arm) around the shoulder from the top to the impact in the swing plane P based on the arm length R ω ₁ = V _GE / R.

<2-2-4. Swing index calculation process (S24)>
Hereinafter, the swing index calculation step (S24) for calculating the swing index during the swing operation of the reference club based on the behavior of the grip 42 and the shoulder will be described with reference to FIG. The swing index referred to here is an index for determining the optimum club characteristics, is a feature amount that characterizes the swing motion by the golfer 7, and is typically an index that correlates with the optimum club characteristics. The swing indexes of this embodiment are the arm output power P ₁ _ _AVE and the club input power P ₂ _ _AVE that correlate with the optimum shaft weight, which is the optimum club characteristic.

First, in step S31, the determination unit 24B integrates the angular velocity ω ₁ of the arm and calculates the rotation angle θ ₁ of the arm from the top to the impact. The rotation angle θ ₁ is defined as shown in FIG. 11, and the paper surface of FIG. 11 is equal to the swing plane P. In the following, the analysis will proceed based on the new XY coordinate system in the swing plane P shown in FIG. The new X-axis in the swing plane P is equal to the Y-axis of the XYZ global coordinate system described above, and the new Y-axis is an axis obtained by projecting the Z-axis of the XYZ global coordinate system into the swing plane P.

In addition, the determination unit 24B differentiates the arm of the angular velocity ω _1, to calculate the angular acceleration ω ₁ 'from the top to the impact. Then, determination unit 24B is the position of the center of gravity of the arm from the top to the impact (X _1, Y _1), calculate the velocity (V _X1, V _Y1) and acceleration (A _X1, A _Y1). These values are calculated by substituting the above calculation results into the following equation. However, r is the distance from the shoulder to the center of gravity of the arm. In this embodiment, the center of gravity of the arm is assumed to be in the center of the arm. Therefore, R = 2r.

Next, in step S32, the determination unit 24B performs the same calculation as in step S31 around the grip 42. That is, the grip angular velocity ω _pX = 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. The rotation angle θ ₂ is defined as shown in FIG.

Then, determination unit 24B is, by differentiating the angular velocity ω ₂ of the golf club 4, to calculate the angular acceleration ω ₂ 'from the top to the impact. Then, determination unit 24B, the position of the center of gravity of the golf club 4 from the top to the impact (X _2, Y _2), calculate the velocity (V _X2, V _Y2) and acceleration (A _X2, A _Y2). These values are calculated by substituting the above calculation results into the following equation. 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 predetermined.

Next, in step S33, the determination unit 24B calculates the binding force R ₁ = (R _{X 1} , _{RY 1} ) generated on the shoulder from the top to the impact by substituting the above calculation result into the following equation. At the same time, the binding force R ₂ = (R _X2 , _{RY 2} ) generated in the grip 42 from the top to the impact is calculated. The following equation is based on the balance of translational forces. However, m ₁ is the mass of the arm, and in the present embodiment, the mass m ₁ of the arm is appropriately predetermined. For example, before starting the analysis, the weight of the golfer 7 is input, and the input weight is multiplied by a predetermined coefficient to automatically calculate the mass of the arm. m ₂ is the mass of the entire golf club 4 (hereinafter referred to as the club weight), and g is the gravitational acceleration. Further, m ₂ is a specification of the golf club 4, and is assumed to be predetermined. α is an angle representing the inclination of the swing plane P, and is defined as shown in FIG. 7 (in FIG. 7, α = 90 ° −α').

In the following step S34, the determination unit 24B calculates the torque T _g1 around the center of gravity of the arm from the top to the impact and the torque T _g2 around the center of gravity of the golf club 4 by substituting the above calculation result into the following equation. 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. Further, I ₂ is a specification of the golf club 4 and shall be predetermined.

In the following step S35, the determination unit 24B calculates the arm output power P ₁ and the club input power P ₂ from the top to the impact based on the above calculation result according to the following equation. The following v _g is the velocity vector of the grip 42, and can be calculated by once differentiating the position vector d _g = (2X ₁ , 2Y ₁ ) of the grip 42.

In a 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 momentum to the golf club 4. Conceivable. The power output by the arm (arm output power) P ₁ corresponds to the acceleration of the arm here, and the power input to the golf club 4 (club input power) P ₂ is the momentum given to the golf club 4. Corresponds to.

In the following step S36, the determination unit 24B integrates the arm output power P ₁ in the interval from the top time to the time when the arm output power P ₁ takes the maximum value, and divides the integrated value D ₁ by this integration interval. By doing so, the average arm output power P ₁ _ _AVE during the swing motion is calculated. This integral value D ₁ is the amount of work performed by the golfer's arm during the swing motion. Similarly, the determination unit 24B integrates the club input power P ₂ in the interval from the top time to the time when the club input power P ₂ takes the maximum value, and divides the integrated value D ₂ by this integration interval. , Calculate the average club input power P ₂ _ _AVE during swing motion. This integral value D ₂ is the amount of work performed on the golf club 4 during the swing operation. The integration interval shown here is an example, and for example, an interval from the time to the time of impact can be appropriately set.

The above arm output powers P ₁ , P ₁ _ _AVE can be rephrased as an index showing the strength with which the golfer 7 accumulates the cock during the swing operation. Further, the club input powers P ₂ , P ₂ _ _AVE can be rephrased as an index indicating the strength with which the golfer 7 releases the cock during the swing operation.

<2-2-5. Optimal club characteristic derivation process (S25)>
Next, the flow of the optimum club characteristic derivation step (S25) will be described with reference to FIG. The optimum club characteristic derivation step is a step of determining the optimum club characteristics according to the arm output power P ₁ _ _AVE and the club input power P ₂ _ _AVE , which are the swing indexes calculated in the swing index calculation step (S24). .. The optimum club characteristic of this embodiment is the optimum shaft weight, and the larger the values of P ₁ _ _AVE and P ₂ _ _AVE , the larger the optimum shaft weight is set stepwise. In this embodiment, the optimum shaft weight is derived with a width. Therefore, the optimum shaft weight may be referred to as an optimum shaft weight band below.

Further, in the present embodiment, after fixing the type of the head 41, the swing operation of the virtual club, which is the golf club 4 in which the golfer 7 is actually swinging, is simulated. By the way, the characteristics of the golf club 4 are mainly determined according to the characteristics of each part such as the head 41, the shaft 40, the grip 42 and the ferrule, and among them, it is typical that the characteristics of the golf club 4 are greatly contributed. Specifically, it is a characteristic of the head 41 and the shaft 40. Therefore, in the present embodiment, as the optimum club characteristics, the characteristics of the shaft 40 (hereinafter referred to as the optimum shaft) suitable for the golfer, more specifically, the optimum shaft weight is determined.

First, in step S40, the determination unit 24B determines the type of the head 41 (hereinafter, fixed head). The type of the fixed head can be determined, for example, by having the user directly specify the type of the fixed head via the display unit 21 and the input unit 22, or asking the user various questions and answering the questions. Can also be performed by accepting the above and narrowing down the fixed heads according to a predetermined algorithm from the answer. For example, in the case where the golf club 4 suitable for the golfer 7 is fitted, the information for specifying the favorite head 41 of the golfer 7 is input as the information for specifying the type of the fixed head.

Next, in step S41, determination unit 24B is calculated by the swing index calculation step _{(P 1 _ AVE, P 2} _ AVE) is a point represented by, P ₁ _ _AVE -P ₂ _ shown in FIG. 13 It is determined whether or not it is above the straight line L1 in the _AVE plane, that is, whether or not it belongs to the region A1 (hereinafter, condition 1). Then, when the condition 1 is satisfied, it is determined that 80 g or more is the optimum shaft weight band. On the other hand, if condition 1 is not satisfied in step S41, the process proceeds to step S42. In step S42, the point represented by (P ₁ _ _AVE , P ₂ _ _AVE ) calculated in the swing index calculation step in the determination unit 24B is on the P ₁ _ _{AVE −} P ₂ _ _AVE plane shown in FIG. It is determined whether or not it is above the straight line L2 and below the straight line L1, that is, whether or not it belongs to the region A2 (hereinafter, condition 2). Then, when the condition 2 is satisfied, it is determined that 70 g or more and less than 80 g is the optimum shaft weight band. On the other hand, if the condition 2 is not satisfied in step S42, the process proceeds to step S43. In step S43, the point represented by (P ₁ _ _AVE , P ₂ _ _AVE ) calculated in the swing index calculation step in the determination unit 24B is on the P ₁ _ _{AVE −} P ₂ _ _AVE plane shown in FIG. It is determined whether or not it is above the straight line L3 and below the straight line L2, that is, whether or not it belongs to the region A3 (hereinafter, condition 3). Then, when the condition 3 is satisfied, it is determined that the optimum shaft weight band is 60 g or more and less than 70 g. On the other hand, if the condition 3 is not satisfied in step S43, the process proceeds to step S44. In step S44, the point represented by (P ₁ _ _AVE , P ₂ _ _AVE ) calculated in the swing index calculation step in the determination unit 24B is on the P ₁ _ _{AVE −} P ₂ _ _AVE plane shown in FIG. It is determined whether or not it is above the straight line L4 and below the straight line L3, that is, whether or not it belongs to the region A4 (hereinafter, condition 4). Then, when the condition 4 is satisfied, it is determined that the optimum shaft weight band is 50 g or more and less than 60 g. On the other hand, when the condition 4 is not satisfied in step S44, that is, the point represented by (P ₁ _ _AVE , P ₂ _ _AVE ) calculated in the swing index calculation step is P ₁ _ _AVE −P shown in FIG. _When it is below the straight line L4 in the ₂ _ _AVE plane and belongs to the region A5, it is determined that 55 g or less is the optimum shaft weight band.

The optimum club characteristic derivation step of the present embodiment is based on the following findings. That is, the present inventors made a large number of golfers swing the test club, and calculated the arm output power P ₁ _ _AVE and the club input power P ₂ _ _AVE at this time. Further, after fixing the head to the same golfer, a test club having shafts of various weights was swung, and the shaft weight giving the maximum flight distance was calculated, and this was set as the optimum shaft weight.

From the above experiment, the optimum shaft weight correlates with the arm output power P ₁ _ _AVE and the club input power P ₂ _ _AVE, and the larger these indexes P ₁ _ _{AVE −} P ₂ _ _AVE , the larger the tendency. It was confirmed that it was in. As a result, the present inventors have found that the arm output power P ₁ _ _AVE − club input power P ₂ _ _AVE space can be divided into regions A1 to A5 representing the optimum shaft weight band as shown in FIG. discovered. That is, it was found that the optimum shaft weight band can be determined according to which region in the P ₁ _ _{AVE −} P ₂ _ _AVE space the points indicating the index P ₁ _ _{AVE −} P ₂ _ _AVE are plotted. The correspondence data 28 stored in advance in the storage unit 23 specifies the threshold value used for the determination in steps S41 to S44, in other words, the boundary lines L1 to L4 of the divided regions A1 to A5 shown in FIG. Information to be done. The boundary lines L1 to L4 are substantially parallel to each other, and are straight lines having a negative slope in the P ₁ _ _{AVE −} P ₂ _ _AVE plane.

That is, the correspondence data 28 is data that determines the correspondence between the swing index (P ₁ _ _AVE , P ₂ _ _AVE ) and the optimum club characteristics (optimum shaft weight band). In steps S41 to S44, the correspondence data 28 in the storage unit 23 is referred to, and the above determination is performed. Although the correspondence data 28 is shown as data different from the golf swing analysis program 3 in FIG. 2, it may be incorporated in the program 3. Further, in the present embodiment, the correspondence data 28 is prepared in advance for each type of the head 41, and the correspondence data 28 corresponding to the type of the head 41 specified in step S40 is selected and stored in the storage unit 23. Is read from and used in steps S41-S44.

<2-2-6. Optimal club selection process (S26)>
Next, an optimum club selection step (S26) for selecting an optimum club that matches the optimum club characteristics (in the present embodiment, the optimum shaft weight) will be described. First, the determination unit 24B extracts all the shafts 40 belonging to the optimum shaft weight band derived in the optimum club characteristic derivation step (S25) as the optimum shafts from the shafts 40 registered in the shaft DB 29. Then, the golf club 4 in which the fixed head and the optimum shaft are combined is determined as the optimum club. At this time, in many cases, a large number of optimum shafts are extracted, but as a result, when a large number of optimum clubs exist, an appropriate one is selected.

The method of narrowing down the optimum club can be appropriately selected. For example, based on the measurement data, another optimum club characteristic other than the optimum shaft weight can be derived, and the optimum club can be narrowed down on condition that the optimum club characteristic is matched. Of course, the optimum club characteristics referred to here are not limited to those related to the characteristics of the shaft 40, but may be related to the characteristics of the entire golf club 4, and the characteristics of other parts such as the head 41 and the grip 42. It may be related to. Further, examples of the characteristics of the shaft 40 referred to here include flex, torque, tone, and the International Flex Code (IFC) widely proposed by the applicant. For example, Japanese Patent Application Laid-Open No. 2013-226375, Japanese Patent Application Laid-Open No. 2014-1214112 and the like disclose methods for deriving an IFC suitable for a golfer, and these techniques can be referred to as necessary. it can. Further, the club weight m ₂ suitable for the golfer 7, the moment of inertia I ₂ around the center of gravity, the swing moment of inertia I _S described later, the moment of inertia I _G around the grip end, and the like can also be the optimum club characteristics. Even when the optimum club is determined based on the optimum club characteristics other than the optimum shaft weight, a swing index having a correlation with the optimum club characteristics is calculated based on the measurement data, and the optimum club characteristics are derived based on the swing index. can do.

It is also possible to determine the optimum club by using the optimum club characteristics for narrowing down the optimum clubs listed here without using the optimum shaft weight. That is, the optimum club characteristic may relate to any characteristic of the golf club 4 as long as the optimum club can be determined.

<2-3. Comparison step (S3)>
In the comparison step (S3) executed after the optimum club determination step (S2), the simulation unit 24C determines which of the reference club and the optimum club has the smaller swingability index. Here, the ease of swinging the golf club 4 can be evaluated by various indexes, one of which is the club weight m ₂ . That is, in general, the golf club 4 tends to have a larger swingability index as the club weight m ₂ is larger, and the swingability index tends to be smaller as the club weight m ₂ is smaller.

The ease of swinging the golf club 4 can be evaluated by an index other than the club weight m ₂ . For example, the ease of swing can be evaluated by indexes such as the swing moment of inertia I _S , the moment of inertia I _G around the grip end, and the moment of inertia I ₂ around the center of gravity described above. Note that the swing moment of inertia I _S, a moment of inertia about the shoulder during the swing, for example, can be defined according to the following formula. At this time, constant arm length R (e.g., 60cm) as may be defined swing moment of inertia I _S.
IS = I ₂ + m ₂ (R + L) ²

Further, the moment of inertia I _G around the grip end, for example, can be defined as the following equation.
_IG = I ₂ + m ₂ L ²

In the present embodiment, the swingability is compared by the club weight m _2, and when it is determined that the reference club is lighter, that is, the reference club has a smaller swingability index, the simulation step of step S4. Is executed. On the other hand, when it is determined that the optimum club is lighter, that is, the optimum club has a smaller swingability index, the simulation step of step S5 is executed.

Further, the swingability index of the optimum club is determined based on the information indicating the specifications of the fixed head stored in the head DB 27 and the information indicating the specifications of the optimum shaft stored in the shaft DB 29. The same applies to the swingability index of the reference club. Using the information for specifying the type of the head 41 and the shaft 40 of the reference club as a key, the specifications of the head 41 and the shaft 40 of the reference club can be obtained from the head DB 27 and the shaft DB 29. Information indicating the above is read out and determined based on this information. Information for specifying the types of the head 41 and the shaft 40 of the reference club is acquired, for example, through the input of the user via the input unit 22 or the like.

Meanwhile, As described above, and club weight m _2, various moment of inertia I _S, I _G, I _2, etc., is an index representing the swing easiness of the golf club 4. Then, a relationship as shown in FIG. 14 or FIG. 15 is established between the swingability index of the golf club 4 and the specific index representing the characteristics of the swing motion of the golfer 7. For example, the head speed at impact can be applied to the model of FIG. 14, and the force exerted by the golfer 7 during the swing operation (hereinafter referred to as the exerted force) can be applied to the model of FIG.

In selecting a golf club, the swingability index serves as one criterion, but as disclosed in Japanese Patent Application Laid-Open No. 2016-19718, the smaller the swingability index is, the better. As shown in FIG. 14, even if the golf club is lightened by a certain amount or more, it cannot be swung with a force equal to or more than the full swing, and the golfer feels the golf club lightly and unconsciously adjusts so that the force becomes smaller. Therefore, the head speed reaches a plateau and the flight distance reaches the limit. On the other hand, when the golf club becomes heavier, the golfer's power cannot swing the golf club off, the head speed decreases, and the flight distance also decreases. Further, as shown in FIG. 15, the heavier the golf club, the greater the exertion power and the longer the flight distance, but when the golf club becomes heavier than a certain level, the golfer's limit is reached and the exertion power reaches a plateau. That is, even if the swingability index is smaller or larger than that, if the golfer's limit is reached, the flight distance will not increase. Therefore, the swingability index corresponding to the limit of the golfer is a swingability index suitable for the golfer, and a golf club having such a swingability index can be considered to be the optimum club. Further, in the region where the swingability index is smaller than the limit of the golfer, it is considered that not only the head speed at the time of impact but also the observed swing itself is constant regardless of the physical characteristics of the golf club. In this sense, such a region is hereinafter referred to as a “swing constant zone”. Further, in the region where the swingability index is larger than the golfer's limit, the index such as the torque exerted by the golfer during the swing operation (hereinafter referred to as the exerted torque) is constant in addition to the exerted force regardless of the physical characteristics of the golf club. It is thought that In this sense, such a region is hereinafter referred to as a "constant exerted torque zone".

The above finding that a swing constant zone and a exertion torque constant zone exist with the swingability index of the optimum club as a boundary can be useful for simulating the virtual club swing data when the virtual club is swung. The comparison step (S3) is a subsequent simulation by deciding whether the reference club belongs to the swing constant zone or the exertion torque constant zone according to the result of comparing the swingability index of the reference club and the optimum club. This is the process of selecting the algorithm used in the process.

<2-4. Simulation process (S4)>
The simulation step (S4) is executed when it is determined that the reference club has a smaller swingability index than the optimum club. The case where the reference club is determined to have a smaller swingability index than the optimum club is as shown in FIG. 16, and the reference club belongs to the swing constant zone. In this embodiment, swing motions in various virtual clubs having various specifications are simulated.

First, a simulation algorithm for a virtual club having a smaller swingability index than the optimum club, that is, a virtual club belonging to a constant swing zone, will be described. At this time, it is assumed that the swing of the virtual club by the golfer 7 is constant regardless of the physical characteristics of the virtual club and matches the swing of the reference club. The simulation unit 24C estimates the virtual club swing data under such an assumption.

Specifically, under the above assumptions, some indexes (arms) calculated in step S2 based on the measurement data when the reference club is actually swung (that is, the measurement data acquired in step S1). Length R, tilt of swing plane P α, angular velocity of arm ω ₁ , angular velocity of arm θ ₁ , angular acceleration of arm ω ₁ ', acceleration of center of gravity of arm ( _AX1 , A _Y1 ), angular velocity of golf club 4 omega _2, the rotation angle theta ₂ of the golf club 4, the angular acceleration omega ₂ of the golf club 4 ', golf club 4 of the center of gravity acceleration (a _X2, a _Y2) and the like. hereinafter, the) of constant index, the swing of the virtual club It is an index that matches the time of operation. Therefore, these constant indexes can be diverted as virtual club swing data. Therefore, the simulation unit 24C estimates the virtual club swing data based on the above-mentioned constant index and the physical characteristics of the virtual club. The physical properties of the virtual club are, for example, the mass matrix M (and the elements m ₁ , m ₂ , I ₁ , I ₂ ) and the distance L of the center of gravity shown below. In the present embodiment, the physical characteristics of the virtual club indicate information indicating the specifications of the head 41 constituting the virtual club stored in the head DB 27 and the specifications of the shaft 40 constituting the virtual club stored in the shaft DB 29. Determined based on information. Information for specifying the types of the head 41 and the shaft 40 of the virtual club to be simulated is acquired, for example, through the input of the user via the input unit 22 or the like.

In the present embodiment, the simulation unit 24C substitutes the existing constant index and the physical properties of the virtual club into the following equation while changing the physical properties of the virtual club, so that the torque T around the shoulder is used as the virtual club swing data. ₁ and the torque T ₂ around the grip 42 are calculated. The torques T ₁ and T ₂ are the exerted torques.

Further, in the present embodiment, the simulation unit 24C estimates the arm of the golfer 7, the trajectory drawn by the golf club 4 (hereinafter referred to as the swing trajectory), the behavior of the head 41, and the like as further virtual club swing data. The behavior of the head 41 is, for example, the head speed. Specifically, the simulation unit 24C derives the position of the head 41 when the virtual club is swung based on the existing fixed index which is the virtual club swing data and the physical characteristics of the virtual club, and further, the swing trajectory. And the behavior of the head 41 is derived.

Next, a simulation algorithm for a virtual club having a larger swingability index than the optimum club, that is, a virtual club belonging to a constant exertion torque zone, will be described. At this time, it is assumed that the torque exerted when the golfer 7 swings the virtual club is constant regardless of the physical properties of the virtual club. Further, since the optimum club is located at the boundary between the constant swing zone and the constant exertion torque zone and belongs to both zones, the exertion torque when the golfer 7 swings the optimum club is when the golfer 7 swings the virtual club. It is assumed to match the exerted torque. Further, it is assumed that the swing of the optimum club by the golfer 7 matches the swing of the reference club. The simulation unit 24C estimates the virtual club swing data under such an assumption.

Specifically, under the above assumptions, the above-mentioned constant index can be diverted as the optimum club swing data. Therefore, the simulation unit 24C substitutes the above-mentioned constant index and the physical properties of the optimum club into the equation of Equation 8, and obtains the exerted torques T ₁ and T ₂ when the optimum club is swung as the optimum club swing data. calculate. The physical properties of the optimum club are, for example, the above-mentioned mass matrix M (and the elements m ₁ , m ₂ , I ₁ , I ₂ ) and the distance L of the center of gravity described above. In the present embodiment, the physical characteristics of the optimum club indicate the information indicating the specifications of the head 41 that constitutes the optimum club stored in the head DB 27 and the specifications of the shaft 40 that constitutes the optimum club stored in the shaft DB 29. Determined based on information. Information for specifying the types of the head 41 and the shaft 40 of the optimum club is acquired, for example, through the input of the user via the input unit 22 or the like. Further, under the above assumption, the exerted torques T ₁ and T ₂ calculated here match the exerted torques T ₁ and T ₂ when the virtual club is swung, so that they are the optimum club swing data at the same time. , It is also virtual club swing data.

Further, in the present embodiment, the simulation unit 24C estimates the swing trajectory, the behavior of the head 41, and the like as further virtual club swing data. Specifically, the simulation unit 24C changes the physical properties of the virtual club and obtains the above-mentioned exerted torques T ₁ and T ₂ , which are virtual club swing data, the physical properties of the virtual club, and the inclination α of the swing plane P. By substituting into the following equations, the rotation angle θ _{1 of} the arm when swinging various virtual clubs, the position of the center of gravity of the arm (X ₁ , Y ₁ ), the rotation angle θ _{2 of} the virtual club, and the center of gravity of the virtual club The position of (X ₂ , Y ₂ ) is derived. At this time, the value measured at the time of swinging the reference club is diverted to the inclination α of the swing plane P. The following equation is an expansion method model constructed according to the concept of multibody dynamics using the Lagrange undetermined multiplier term, and λ is the undetermined multiplier term. Moreover, in the following formula, the dot attached above the symbol represents the differentiation.

The meanings of the various symbols in the above formula are as follows.

The simulation unit 24C further virtualizes based on the values of θ ₁ , X ₁ , Y ₁ , θ ₂ , X ₂ , and Y ₂ , which are the virtual club swing data derived according to the above equation, and the physical properties of the virtual club. As club swing data, the position of the head 41 is derived, and further, the swing trajectory and the behavior of the head 41 are derived.

<2-5. Simulation process (S5)>
The simulation step (S5) is executed when it is determined that the reference club has a larger swingability index than the optimum club. The case where the reference club is determined to have a larger swingability index than the optimum club is as shown in FIG. 17, and the reference club belongs to the exerted torque constant zone. In this embodiment, swing motions in various virtual clubs having various specifications are simulated.

First, a simulation algorithm for a virtual club having a smaller swingability index than the optimum club, that is, a virtual club belonging to a constant swing zone, will be described. At this time, it is assumed that the swing of the virtual club by the golfer 7 matches the swing of the optimum club. Further, it is assumed that the exerted torques T ₁ and T ₂ when the reference club is swung match the exerted torques T ₁ and T ₂ when the optimum club is swung. The simulation unit 24C estimates the virtual club swing data under such an assumption.

Specifically, the simulation unit 24C calculates the exerted torques T ₁ and T ₂ when the reference club is swung by substituting the above-mentioned constant index and the physical properties of the reference club into the equation of Equation 8. Under the above assumptions, the exerted torques T ₁ and T ₂ calculated here are the optimum club swing data because they match the exerted torques T ₁ and T ₂ when the optimum club is swung. The physical properties of the reference club are, for example, the above-mentioned mass matrix M (and the elements m ₁ , m ₂ , I ₁ , I ₂ ) and the distance L of the center of gravity described above. In the present embodiment, the physical characteristics of the reference club indicate the information indicating the specifications of the head 41 constituting the reference club stored in the head DB 27 and the specifications of the shaft 40 constituting the reference club stored in the shaft DB 29. Determined based on information. Information for specifying the types of the head 41 and the shaft 40 of the reference club is acquired, for example, through the input of the user via the input unit 22 or the like.

Subsequently, the simulation unit 24C substitutes the above-mentioned exerted torques T ₁ and T _2, which are the optimum club swing data, the physical properties of the optimum club, and the inclination α of the swing plane P into the equation of equation 9, thereby performing the optimum. Derivation of the rotation angle θ _{1 of} the arm when the club is swung, the position of the center of gravity of the arm (X ₁ , Y ₁ ), the rotation angle θ _{2 of} the virtual club, and the position of the center of gravity of the virtual club (X ₂ , Y ₂ ). .. At this time, the value measured at the time of swinging the reference club is diverted to the inclination α of the swing plane P. Under the above assumptions, the values of θ ₁ , X ₁ , Y ₁ , θ ₂ , X ₂ , and Y ₂ derived here are not only optimal club swing data but also virtual club swing data. Then, the simulation unit 24C is based on the values of the virtual club swing data θ ₁ , X ₁ , Y ₁ , θ ₂ , X ₂ , Y ₂ and the physical properties of the virtual club while changing the physical properties of the virtual club. Then, as further virtual club swing data, the position of the head 41 is derived, and further, the swing trajectory and the behavior of the head 41 are derived. Further, the simulation unit 24C changes the physical characteristics of the virtual club while changing the values of the virtual club swing data θ ₁ , X ₁ , Y ₁ , θ ₂ , X ₂ , Y ₂ , α, and the virtual club. By substituting the physical characteristics of the above into the equation of Eq. 8, the exerted torques T ₁ and T ₂ are calculated as further virtual club swing data.

Next, a simulation algorithm for a virtual club having a larger swingability index than the optimum club, that is, a virtual club belonging to a constant exertion torque zone will be described. At this time, it is assumed that the exerted torque when the golfer 7 swings the virtual club is constant regardless of the physical characteristics of the virtual club, and matches the exerted torque when the golfer 7 actually swings the reference club. The simulation unit 24C estimates the virtual club swing data under such an assumption.

Specifically, the simulation unit 24C calculates the exerted torques T ₁ and T ₂ when the reference club is swung by substituting the above-mentioned constant index and the physical properties of the reference club into the equation of Equation 8. Incidentally, exerts a torque T ₁ calculated here, T _2, under the above assumption, for matching exerts torque T _1, T ₂ when the swing virtual club, to represent the swing operation of the reference clubs At the same time, it is also virtual club swing data.

Further, the simulation unit 24C changes the physical properties of the virtual club, and changes the physical properties of the virtual club by the above-mentioned exerted torques T ₁ and T ₂ which are virtual club swing data, the inclination α of the swing plane P, and the physical properties of the virtual club. By substituting into the equation, the rotation angle of the arm when swinging various virtual clubs θ ₁ , the position of the center of gravity of the arm (X ₁ , Y ₁ ), the rotation angle of the virtual club θ ₂ , the position of the center of gravity of the virtual club Derivation of (X ₂ , Y ₂ ). At this time, the value measured at the time of swinging the reference club is diverted to the inclination α of the swing plane P. The simulation unit 24C further virtual club swing data based on the values of θ ₁ , X ₁ , Y ₁ , θ ₂ , X ₂ , and Y ₂ , which are the virtual club swing data derived in this way, and the physical characteristics of the virtual club. As a result, the position of the head 41 is derived, and further, the swing trajectory and the behavior of the head 41 are derived.

<2-6. Output process (S6)>
When the above analysis is completed, the display control unit 24D displays the result of the above analysis on the display unit 21. Specifically, the exerted torques T ₁ and T ₂ , the swing trajectory, and the behavior of the head 41 of the reference club, the optimum club, and the virtual club are visualized by using a graph or the like. As a result, the user can know the behavior when the golfer 7 swings the optimum club, and can also know the behavior when swinging another virtual club as a reference. Therefore, for example, in the case of fitting, the effect of selecting the optimum club can be grasped, and in some cases, one of the virtual clubs can be selected as the optimum golf club 4. ..

<3. Modification example>
Although some embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, the following changes can be made. In addition, the gist of the following modified examples can be combined as appropriate.

<3-1>
In the above embodiment, the inertial sensor unit 1 having the acceleration sensor 11, the angular velocity sensor 12, and the geomagnetic sensor 13 is used as the measuring device for measuring the swing motion of the golfer 7, but the measuring device has another configuration. You can also do it. For example, the geomagnetic sensor 13 can be omitted. Alternatively, as the measuring device, a three-dimensional measuring camera having a distance measuring function or a three-dimensional measuring camera composed of a plurality of cameras can be used. Since a method for measuring the behavior of the golfer 7, the golf club 4, and the golf ball with a three-dimensional measurement camera is also known, detailed description thereof will be omitted here.

<3-2>
In the above embodiment, the optimum club characteristics are determined based on the arm output power P ₁ _ _AVE and the club input power P ₂ _ _AVE , but the swing index for determining the optimum club characteristics is, of course, limited to these. Absent. As another example of the swing index for determining the optimum club characteristics, it is exhibited by the golfer 7 during the swing operation, for example, as disclosed in Japanese Patent Application Laid-Open No. 2016-344383 by the same applicants. Various energies, various torques exerted by the golfer 7, and the head speed immediately before impact can be mentioned. In addition, these various swing indexes can be used alone or in any combination.

1 Inertia sensor unit (measuring equipment)
2 Golf swing swing analysis device 24A Acquisition unit 24B Determination unit 24C Simulation unit 3 Golf swing swing analysis program 7 Golfer 4 Golf club 40 Shaft 41 Head 42 Grip

Claims (15)

A golf swing analysis device that analyzes the swing motion of a golf club.
An acquisition unit that acquires measurement data obtained by measuring the swing motion of a reference club by a golfer with a measuring device,
Based on the measurement data, a determination unit that derives the optimum club characteristics representing the club characteristics suitable for the golfer and determines the optimum club that is a golf club that matches the optimum club characteristics.
The optimum club swing data representing the swing motion of the optimum club by the golfer is calculated, and the golfer is based on the optimum club swing data and the physical properties of a virtual club which is a golf club in which the golfer does not actually swing. A simulation unit for estimating virtual club swing data representing the swing motion of the virtual club is provided .
The simulation unit compares the club characteristics of the optimum club and the reference club, and estimates the virtual club swing data according to an algorithm selected according to the result of the comparison.
Golf swing analyzer. A golf swing analysis device that analyzes the swing motion of a golf club.
An acquisition unit that acquires measurement data obtained by measuring the swing motion of a reference club by a golfer with a measuring device,
Based on the measurement data, a determination unit that derives the optimum club characteristics representing the club characteristics suitable for the golfer and determines the optimum club that is a golf club that matches the optimum club characteristics.
The optimum club swing data representing the swing motion of the optimum club by the golfer is calculated, and the golfer is based on the optimum club swing data and the physical properties of a virtual club which is a golf club in which the golfer does not actually swing. With a simulation unit that estimates virtual club swing data representing the swing motion of the virtual club
With
The virtual club swing data includes torque exerted by the golfer during the swing operation of the virtual club.
Gore Rufusuingu analyzer. A golf swing analysis device that analyzes the swing motion of a golf club.
An acquisition unit that acquires measurement data obtained by measuring the swing motion of a reference club by a golfer with a measuring device,
Based on the measurement data, a determination unit that derives the optimum club characteristics representing the club characteristics suitable for the golfer and determines the optimum club that is a golf club that matches the optimum club characteristics.
The optimum club swing data representing the swing motion of the optimum club by the golfer is calculated, and the golfer is based on the optimum club swing data and the physical properties of a virtual club which is a golf club in which the golfer does not actually swing. With a simulation unit that estimates virtual club swing data representing the swing motion of the virtual club
With
The virtual club swing data includes at least one of the swing trajectory and the head speed during the swing operation of the virtual club.
Gore Rufusuingu analyzer. The simulation unit estimates the virtual club swing data on the assumption that when the virtual club has smaller club characteristics than the optimum club, the swing of the golfer is constant regardless of the physical properties of the virtual club. ,
The golf swing analysis device according to any one of claims 1 to 3 . The simulation unit assumes that when the virtual club has larger club characteristics than the optimum club, the force exerted by the golfer during the swing operation is constant regardless of the physical properties of the virtual club. Estimate swing data,
The golf swing analysis device according to any one of claims 1 to 4 . Based on the measurement data, the determination unit derives a swing index during the swing operation of the reference club, and derives the optimum club characteristic according to the swing index.
The golf swing analysis device according to any one of claims 1 to 5 . The swing index includes at least one of the power output by the golfer's arm, the power input to the reference club, the energy exerted by the golfer, the torque exerted by the golfer, and the head speed immediately before impact. Includes
The golf swing analysis device according to claim 6 . The optimum club characteristic is an index of ease of swinging a golf club suitable for the golfer.
The golf swing analysis device according to any one of claims 1 to 7 . The optimum club characteristics include at least one of a club weight suitable for the golfer, a shaft weight, a moment of inertia around the shoulder of the golfer, and a moment of inertia of a golf club.
The golf swing analysis device according to claim 8 . A golf swing analysis method that analyzes the swing motion of a golf club.
A step to acquire measurement data obtained by measuring the swing motion of a reference club by a golfer with a measuring device,
Based on the measurement data, a step of deriving an optimum club characteristic representing the club characteristic suitable for the golfer and determining an optimum club which is a golf club matching the optimum club characteristic,
The optimum club swing data representing the swing motion of the optimum club by the golfer is calculated, and the golfer is based on the optimum club swing data and the physical properties of a virtual club which is a golf club in which the golfer does not actually swing. look including the step of estimating a virtual club swing data representing the swing motion of the virtual club by,
The estimation step includes a step of comparing the club characteristics of the optimum club and the reference club and estimating the virtual club swing data according to an algorithm selected according to the result of the comparison.
Golf swing analysis method. A golf swing analysis method that analyzes the swing motion of a golf club.
A step to acquire measurement data obtained by measuring the swing motion of a reference club by a golfer with a measuring device,
Based on the measurement data, a step of deriving an optimum club characteristic representing the club characteristic suitable for the golfer and determining an optimum club which is a golf club matching the optimum club characteristic,
The optimum club swing data representing the swing motion of the optimum club by the golfer is calculated, and the golfer is based on the optimum club swing data and the physical properties of a virtual club which is a golf club in which the golfer does not actually swing. With the step of estimating the virtual club swing data representing the swing motion of the virtual club
Including
The virtual club swing data includes torque exerted by the golfer during the swing operation of the virtual club.
Golf swing analysis method. A golf swing analysis method that analyzes the swing motion of a golf club.
A step to acquire measurement data obtained by measuring the swing motion of a reference club by a golfer with a measuring device,
Based on the measurement data, a step of deriving an optimum club characteristic representing the club characteristic suitable for the golfer and determining an optimum club which is a golf club matching the optimum club characteristic,
The optimum club swing data representing the swing motion of the optimum club by the golfer is calculated, and the golfer is based on the optimum club swing data and the physical properties of a virtual club which is a golf club in which the golfer does not actually swing. With the step of estimating the virtual club swing data representing the swing motion of the virtual club
Including
The virtual club swing data includes at least one of the swing trajectory and the head speed during the swing operation of the virtual club.
Golf swing analysis method. A golf swing analysis program that analyzes the swing motion of a golf club.
A step to acquire measurement data obtained by measuring the swing motion of a reference club by a golfer with a measuring device,
Based on the measurement data, a step of deriving an optimum club characteristic representing the club characteristic suitable for the golfer and determining an optimum club which is a golf club matching the optimum club characteristic,
The optimum club swing data representing the swing motion of the optimum club by the golfer is calculated, and the golfer is based on the optimum club swing data and the physical properties of a virtual club which is a golf club in which the golfer does not actually swing. The computer is made to execute a step of estimating the virtual club swing data representing the swing operation of the virtual club .
The estimation step includes a step of comparing the club characteristics of the optimum club and the reference club and estimating the virtual club swing data according to an algorithm selected according to the result of the comparison.
Golf swing analysis program. A golf swing analysis program that analyzes the swing motion of a golf club.
A step to acquire measurement data obtained by measuring the swing motion of a reference club by a golfer with a measuring device,
Based on the measurement data, a step of deriving an optimum club characteristic representing the club characteristic suitable for the golfer and determining an optimum club which is a golf club matching the optimum club characteristic,
The optimum club swing data representing the swing motion of the optimum club by the golfer is calculated, and the golfer is based on the optimum club swing data and the physical properties of a virtual club which is a golf club in which the golfer does not actually swing. With the step of estimating the virtual club swing data representing the swing motion of the virtual club
Let the computer run
The virtual club swing data includes torque exerted by the golfer during the swing operation of the virtual club.
Golf swing analysis program. A golf swing analysis program that analyzes the swing motion of a golf club.
A step to acquire measurement data obtained by measuring the swing motion of a reference club by a golfer with a measuring device,
Based on the measurement data, a step of deriving an optimum club characteristic representing the club characteristic suitable for the golfer and determining an optimum club which is a golf club matching the optimum club characteristic,
The optimum club swing data representing the swing motion of the optimum club by the golfer is calculated, and the golfer is based on the optimum club swing data and the physical properties of a virtual club which is a golf club in which the golfer does not actually swing. With the step of estimating the virtual club swing data representing the swing motion of the virtual club
Let the computer run
The virtual club swing data includes at least one of the swing trajectory and the head speed during the swing operation of the virtual club.
Golf swing analysis program.