This application claims priority to and the benefit of Japanese Patent Application No. 2019-116596 filed on Jun. 24, 2019, the entire disclosure of which is incorporated herein by reference.
The present invention relates to an information processing technique concerning behavior analysis in the golf field.
There are various techniques for analyzing a swing motion of a golfer. Japanese Patent Laid-Open No. 2017-023638 discloses a technique of measuring the incident angle and the like of a golf club head and analyzing a swing motion. Japanese Patent Laid-Open No. 2017-023639 discloses a technique of measuring the rotation angle and the like of a golf club and analyzing a swing motion. Japanese Patent Laid-Open No. 2017-070366 discloses a technique of estimating a striking position on a face surface at the time of striking. Japanese Patent Laid-Open No. 2017-000179 discloses a technique of analyzing the behavior of a golf club head and predicting the ball flight of a shot. There is also proposed a technique of recommending a golf item suitable for a golfer based on such analysis result (for example, Japanese Patent Laid-Open No. 2011-015968).
The behavior of a shot such as the initial speed, launch angle, and spin amount of a golf ball immediately after striking is one of matters of high concern for a golfer. In general, the behavior of a shot is actually measured by a measuring facility such as a camera or a doppler radar. If there is no such measuring facility, the golfer cannot know the behavior of a shot as a result of his/her swing motion. Japanese Patent Laid-Open No. 2017-000179 proposes a technique of predicting the ball flight of a shot. However, the technique predicts the behavior of a golf club head, and analyzes a collision of the head with a golf ball, and thus calculation is complicated.
The present invention has as its object to provide a technique of estimating the behavior of a shot without requiring a measuring facility such as a camera or a doppler radar.
According to an aspect of the present invention, there is provided an information processing apparatus comprising: an acquisition unit configured to acquire a measurement result of a golf swing motion of a golfer; and a calculation unit configured to calculate a behavior of a shot by the golf swing motion, wherein the measurement result includes a head speed, an incident angle, and a face angle at the time of striking of a golf club head, the behavior of the shot includes an initial speed, a vertical launch angle, and a back spin amount, and the calculation unit calculates the behavior of the shot by substituting the head speed, the incident angle, and the face angle, all of which have been acquired by the acquisition unit, into a predetermined arithmetic formula having a plurality of variables including at least a head speed, an incident angle, and a face angle at the time of striking of a golf club head.
Further features of the present invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawings).
Hereinafter, embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments are not intended to limit the scope of the claimed invention, and limitation is not made an invention that requires all combinations of features described in the embodiments. Two or more of the multiple features described in the embodiments may be combined as appropriate. Furthermore, the same reference numerals are given to the same or similar configurations, and redundant description thereof is omitted.
<Arrangement of System>
The measuring apparatus 2 is an apparatus that measures a golf swing motion of a golfer 10. In this embodiment, the measuring apparatus 2 is an apparatus that measures the behavior of a golf club 100. The golf club 100 includes a head 101 having a face surface (striking surface) 101a, and a shaft 102 connected to the head 101. A grip (not shown) is attached to the end portion of the shaft 102 on the side of the golfer 10. The measuring apparatus 2 is an apparatus attached to the shaft 102 (or grip) of the golf club 100, and includes an acceleration sensor and an angular velocity sensor. As the measuring apparatus 2, for example, TSND121 available from ATR-Promotions or M-tracer available from Seiko Epson Corporation can be used. As a result of detection of the measuring apparatus 2, time-series data of the three-dimensional acceleration and three-dimensional angular velocity of the golf club 100 during a swing are obtained.
The information processing apparatus 3 is a computer that estimates, from the measurement result of the measuring apparatus 2 and the like, the behavior of a shot of a golf ball 200 struck by a golf swing motion of the golfer 10 with the golf club 100. The information processing apparatus according to this embodiment also has a function of recommending a golf item suitable for the golfer 10 based on the estimated behavior of the shot. The golf item includes a golf club or a golf ball. The information processing apparatus 3 includes a processing unit 31, a storage unit 32, and an I/F unit (interface unit) 33 which are electrically connected to each other. The processing unit 31 is a processor such as a CPU. The storage unit 32 includes one or a plurality of storage devices. The storage devices are, for example, a RAM, a ROM, and a hard disk. The storage unit 32 stores a program to be executed by the processing unit 31, and various kinds of data. The program to be executed by the processing unit 31 can be formed from a plurality of instructions readable by the processing unit 31.
The I/F unit 33 inputs/outputs data between an external device and the processing unit 31. The I/F unit 33 can include an I/O interface and a communication interface. The measuring apparatus 2 is communicably connected to the information processing apparatus 3 by wired or wireless communication, and the measurement result is acquired by the information processing apparatus 3.
The display device 4 and the input device 5 are connected to the information processing apparatus 3. The display device 4 is, for example, an electronic image display device such as a liquid crystal display device, and displays the processing result of the information processing apparatus 3. The input device 5 includes a mouse and a keyboard, and accepts a data input and an operation instruction for the information processing apparatus 3. The display device 4 may be a device having an information input function like a touch panel. In this case, the input device 5 need not be provided.
<Estimation of Behavior of Shot>
The ball flight of the golf ball 200 struck by a golf swing motion of the golfer 10 is important for him/her. The ball flight of the golf ball is estimated based on the behavior of the shot such as the initial speed, the vertical and horizontal launch angles, the back spin amount, and the side spin amount of the golf ball 200 immediately after striking. The behavior of the shot can be actually measured by a measuring facility such as a camera or a doppler radar. In this embodiment, however, the behavior of the shot is estimated based on the measurement result of the measuring apparatus 2 or the like without requiring any such measuring facility.
<Generation of Arithmetic Formula>
In this embodiment, the behavior of the golf ball 200 is estimated by an arithmetic formula (model) having the measurement result of the golf swing motion of the golfer 10 and the like as explanatory variables and the behavior of the golf ball 200 immediately after striking as a target variable. As an advance preparation, an arithmetic formula is generated.
As the explanatory variables, the measurement result of the golf swing motion of the golfer 10, the attributes of the golfer 10, and the attributes of a golf item can be used. The measurement result of the golf swing motion can include a measurement result obtained by the measuring apparatus 2 or another measurement method. The measurement result obtained by the measuring apparatus 2 can include the head speed of the head 101 at the time of striking, the incident angle of the head 101, and the face angle at the time of striking.
Referring to
Referring to
The measurement result of the measuring apparatus 2 can additionally include a face rotation, a flexure return time, a loft angle at the time of striking, and a swing trajectory. The face rotation indicates a change degree of the face surface 101a during a swing, and is, for example, a rotation amount around the axis of the shaft 102 per unit time immediately before striking. The unit time is, for example, 0.01 sec immediately before striking. The flexure return time indicates a time from when the acceleration of a predetermined portion (for example, the distal end portion of the grip) of the golf club becomes maximum until an impact. In general, during a golf swing, the shaft 102 has a tendency that it is flexed, after a down swing, in a direction in which the head 101 is behind the proximal end side, and decelerates on the proximal end side before striking, and then the flexure of the shaft 102 returns to reach an impact. The flexure return time can be regarded as a time until the flexure of the shaft 102 returns before striking. The loft angle at the time of striking indicates an angle between a vertical plane and the face surface 101a at the time of striking on the X-Z plane. The swing trajectory indicates the angle of the trajectory of the head 101 in the Y direction at the time of striking the golf ball 200 with respect to the X direction on the X-Y plane.
The measurement result of the golf swing motion can additionally include the striking position of the golf ball 200 on the face surface 101a.
The attributes of the golfer 10 can include the feature amounts of the golfer such as the sex, height, weight, and age. The attributes of the golf item can include the attributes of a golf club and those of a golf ball. The attributes of the golf club can include the feature amounts of the overall golf club, those of the shaft, those of the head, and those of the grip. The feature amounts of the overall golf club can include the total weight, balance, and product type of the golf club. The feature amounts of the shaft can include the length, rigidity, flex, torque, kick point, and weight. The feature amounts of the head can include the center-of-gravity depth, center-of-gravity height, center-of-gravity distance, center-of-gravity angle, loft angle, and weight. The feature amounts of the grip can include the weight and material.
With respect to the target variable of the behavior of the shot, the initial speed of the shot is the speed of the golf ball 200 immediately after striking.
An arithmetic formula can be generated using an actual measured data group formed from an actual measured data group of the target variable corresponding to the above-described data group of the explanatory variables. The target variable is actually measured by the measuring facility such as a camera or a doppler radar. For example, TRACKMAN available from TRACKMAN can be used.
The arithmetic formula can be derived by, for example, machine learning using the actual measured data group as supervised data.
In step S1, the actual measured data group is loaded as supervised data. The actual measured data group can be accumulated in advance in an external storage device in a predetermined data format. In step S2, various settings of a learning method are made, and machine learning is executed based on the supervised data loaded in step S1. In step S3, an arithmetic formula is generated as a product. The generated arithmetic formula is stored in the storage unit 32 of the information processing apparatus 3, and used to estimate the behavior of the shot.
Examples of an algorithm of machine learning are linear regression using stochastic gradient descent, ridge regression, lasso regression, support vector regression, and deep learning. For linear regression using stochastic gradient descent, ridge regression, or lasso regression, when the target variable is represented by y, the explanatory variable is represented by x, and a coefficient is represented by a, a linear formula can be used as the arithmetic formula, given by:
y1=a1·x1+a2·x2+a3·x3 . . .
Then, the coefficient a is obtained by machine learning in step S2, thereby completing the arithmetic formula. For lasso regression or deep learning, the formula and the coefficients in the formula can be obtained by machine learning in step S2. For lasso regression, the type of explanatory variable used finally can also be determined by machine learning.
According to an experiment related to this embodiment, if, among the explanatory variables, especially the head speed, the incident angle of the head, and the face angle at the time of striking had high correlations with the behavior (the initial speed of the ball, the vertical and horizontal launch angles, the back spin amount, and the side spin amount) of the shot, and were used as explanatory variables, predetermined accuracy could be obtained with respect to estimation of the behavior of the shot. Therefore, at least the head speed and the face angle at the time of striking are adopted as explanatory variables. In this case, if the arithmetic formula is set by the above linear formula, for example,
initial speed of ball=a1·head speed+a2·incident angle+a3·face angle+a0
vertical launch angle=a11·head speed+a12·incident angle+a13·face angle+a10
Among the explanatory variables, the striking position also has high correlation with the behavior (the initial speed of the ball, the vertical and horizontal launch angles, the back spin amount, and the side spin amount) of the shot, thereby improving the estimation accuracy. In this case, if the arithmetic formula is set by the above linear formula, for example,
side spin amount=a21·head speed+a22·incident angle+a23·face angle+a24·striking position+a20
The explanatory variables used for the arithmetic formula are not limited them, as a matter of course. All or some of the attributes of the golfer or all or some of the attributes of the golf item may be included. With respect to the target variable, if the initial speed of the shot, the vertical launch angle, and the back spin amount are provided, the ball flight can be estimated accurately to some extent. If the horizontal launch angle and the side spin amount are further added, it is also possible to estimate the degree of left or right bending of the shot, thereby improving the estimation accuracy of the ball flight.
Note that the arithmetic formula may be derived by a method other than machine learning, for example, correlation analysis. For example, the arithmetic formulas may be derived from the actual measured data group by multiple regression analysis. For multiple regression analysis, by representing a coefficient by b, the arithmetic formulas can be given by:
initial speed of ball=head speed×(b0+b1·incident angle+b2·face angle+b3·√(striking position in direction D3)2+(striking position in direction D2)2)
vertical launch angle=b11×incident angle+b12·face angle+b13·striking position in direction D3+b10
back spin amount=b21·incident angle+b22·face angle+b23·striking position in direction D3+b20
horizontal launch angle=b31·swing trajectory+b32·face angle+b33·striking position in direction D3+b34·striking position in toe-heel direction
side spin amount=b41·incident angle+b42·swing trajectory+b43·face angle+b44·striking position in direction D2
<Estimation Processing and Selection of Recommended Item>
In step S12, the arithmetic formula stored in the storage unit 32 is read out. In step S13, the explanatory variables to be used for estimation of this time, which have been accepted in step S11, are read out. In step S14, the explanatory variables read out in step S13 are substituted into the arithmetic formula read out in step S12, thereby calculating the target variable. This can obtain the estimated value of the behavior of the shot.
In step S15, the ball flight of the shot is estimated based on the target variable calculated in step S14. An example of contents of the estimated ball flight can be a distance of the shot in the target line direction (X direction).
Referring back to
Information for matching the golf item and the behavior of the shot or the estimation result of the ball flight is stored in the storage unit 32, and used to select a recommended item in step S16.
The region R2 is a region of a behavior of a small launch angle and a large back spin amount. The region R2 is assigned with a golf ball product with specifications in which the ball is easy to fly high and the back spin amount is suppressed, as compared with the product with the standard specifications. The region R3 is a region of a behavior of a large launch angle and a small back spin amount. The region R3 is assigned with a golf ball product with specifications in which the ball is difficult to fly high and the back spin amount is increased, as compared with the product with the standard specifications. The region R4 is a region of a behavior of a small launch angle and a small back spin amount. The region R4 is assigned with a golf ball product with specifications in which the ball is easy to fly high and the back spin amount is increased, as compared with the product with the standard specifications.
In the example shown in
The golf ball product BA is, for example, a golf ball that has a soft core and a soft cover, and has a characteristic that it is easy to spin. The golf ball product BB is, for example, a golf ball that has a soft cover and a hard core, and has a characteristic that it is easy to spin. The golf ball product BC is, for example, a golf ball that has a soft core and a hard cover, and has a characteristic that it is difficult to spin.
For a golfer whose initial speed of a shot is higher than the threshold, power to crush the golf ball at the time of striking is large. In the example shown in
The example shown in
Referring back to
In the first embodiment, the attributes of the golfer and those of the golf item have been exemplified as examples of the explanatory variables. However, a method of selecting one of arithmetic formulas respectively set for the attributes of a golfer and those of a golf item without using the attributes of the golfer and those of the golf item as explanatory variables may be adopted.
In an example shown in
In addition, each of arithmetic formulas M and K is generated in accordance with the attribute of a golf item. Each arithmetic formula is generated by distinguishing among golf ball products. The arithmetic formula M is derived from a data group of a golf swing motion of a golfer using a golf ball product X and an actual measured data group of the behavior of a corresponding shot. The arithmetic formula K is derived from a data group of a golf swing motion of a golfer using a golf ball product Y and an actual measured data group of the behavior of a corresponding shot.
In this embodiment, if the processing shown in
Note that distinction of each arithmetic formula shown in
The attribute of the golfer for distinguishing each arithmetic formula is not limited to the sex, and another attribute such as the height, weight, length of golf experience, or handicap may be used. Similarly, the attribute of the golf item for distinguishing each arithmetic formula is not limited to the golf ball product, and another attribute such as a golf club product, a head weight, a shaft flex, the layer structure of a ball, the spin characteristic of a ball, or the distance characteristic of a ball may be used.
In the system shown in
An arrangement example EX1 on the measuring side includes the mobile terminal 301 and a measuring apparatus 2. This system is suitable for a golfer to individually estimate the behavior of a shot. The mobile terminal 301 is, for example, a smartphone, and has a short distance wireless communication function with the measuring apparatus 2 and a wireless communication function via the network 300 and a base station (not shown). The mobile terminal 301 transmits, to the information processing apparatus 3, the values of explanatory variables such as a measurement result received from the measuring apparatus 2. The information processing apparatus 3 calculates a target variable, and transmits each piece of information such as ball flight estimation or a recommended item to the mobile terminal 301. The mobile terminal 301 displays the received information. That is, the mobile terminal 301 executes processes in steps S11 and S17 of
An arrangement example EX2 on the measuring side includes the personal computer 302 and a plurality of measuring apparatuses 2A. This system is suitable for measuring a golf swing motion in a golf shop or the like. Each measuring apparatus 2A is an image capturing apparatus such as a video camera. The personal computer 302 has a processing function for an image captured by each image capturing 2A, and a wireless communication function via the network 300. A golfer makes a test shot in a test shot box or the like. The testing golfer is captured from multiple directions by the plurality of image capturing apparatuses 2A in the test shot box or the like, thereby capturing the three-dimensional behavior of a golf club 100. The captured images are loaded into the personal computer 302 and analyzed, thereby deriving the values of explanatory variables. Furthermore, the personal computer 302 transmits the values of the explanatory variables to the information processing apparatus 3. The information processing apparatus 3 calculates a target variable, and transmits each piece of information such as ball flight estimation or a recommended item to the personal computer 302. The personal computer 302 displays the received information. That is, the personal computer 302 executes the processes in steps S11 and S17 of
The invention is not limited to the foregoing embodiments, and various variations/changes are possible within the spirit of the invention.
Number | Date | Country | Kind |
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2019-116596 | Jun 2019 | JP | national |