JP6697851B2 - Golf ball trajectory prediction method, golf ball trajectory prediction device, and golf club selection method - Google Patents

Description

  The present invention relates to a golf ball trajectory prediction method, a golf ball trajectory prediction apparatus, and a golf club selection method.

  There is a high demand for a technique for predicting a golf swing, a state of collision between a golf club and a golf ball, a trajectory of a golf ball, and the like by performing calculation. In particular, these prediction techniques are important when fitting (selecting, adjusting, custom-making) a golf club.

Here, in fitting a golf club, a golfer's swing using a club for measurement is measured, and based on the measured swing data, the state of the golf swing when various clubs are used is predicted and predicted. It is common to use the state of the golf swing as one of the fitting indexes.
For example, in Patent Document 1, a golf swing is analyzed based on information including the speed of the grip end of the golf club in an impact state immediately before hitting the golf ball, and the optimum golf club for the golf swing is selected. The technology is disclosed.

  Ideally, the fitting of the golf club is performed based on the trajectory (distance and directionality) of the golf ball after the collision with the golf club. This is because a suitable golf club can be selected according to the flight distance and directionality of the ball desired by the golfer.

Japanese Patent No. 4184363

  Therefore, an object of the present invention is to provide a trajectory predicting method for a golf ball and a trajectory predicting device for a golf ball, which can predict the trajectory of a golf ball with high accuracy. Further, another object of the present invention is to provide a golf club selecting method capable of selecting a suitable golf club.

The gist of the present invention is as follows.
The trajectory predicting method of the golf ball of the present invention measures a swing of a golfer using a test golf club, a swing measuring step, and inputs the measured value of the swing obtained in the swing measuring step as a target golf ball. A head behavior prediction step of predicting the behavior of the head of the golf club when a club is used, and calculation based on the predicted value of the head behavior of the golf club obtained in the head behavior prediction step, A ball trajectory prediction that predicts the trajectory of the golf ball from the ball initial behavior calculation step of calculating the initial behavior of the golf ball after the collision with the golf ball and the initial behavior of the golf ball calculated in the ball initial behavior calculation step. And a process.
With the above configuration, it is possible to accurately predict the trajectory of the golf ball.

  Further, in the trajectory predicting method of the golf ball of the present invention, in the swing measuring step, a meet rate for the golf ball by the swing is further measured, and in the head behavior predicting step, of the swings measured in the swing measuring step, It is preferable to use only the measured value of the swing in which the meet rate is equal to or more than a predetermined threshold value as an input, and the meet rate is the initial speed of the launched ball with respect to the head speed of the golf club at the moment of impact. More preferable. This is because the trajectory of the golf ball can be predicted with higher accuracy.

  In the golf ball trajectory prediction method of the present invention, in the swing measurement step, the initial behavior of the golf ball due to the swing is further measured, and the initial behavior of the golf ball measured in the swing measurement step and the ball initial behavior. It is preferable to compare the initial behavior of the golf ball calculated in the calculation step and correct the calculation result based on the predicted value of the head behavior. This is because the trajectory of the golf ball can be predicted with higher accuracy.

  Further, in the golf ball trajectory prediction method of the present invention, it is preferable that the initial behavior of the golf ball is an initial velocity, a launch angle, and a spin amount after a collision with a head of a golf club. This is because the trajectory of the golf ball can be predicted with higher accuracy.

  Furthermore, in the golf ball trajectory prediction method of the present invention, the initial behavior of the golf ball is calculated by using a regression formula created in advance from a collision analysis of the head and the golf ball, using the predicted value of the head behavior as an input. It is preferable that the calculated value is calculated or calculated from the motion analysis by the finite element method using the predicted value of the head behavior as an input. This is because the accuracy of the calculation for calculating the initial behavior of the golf ball can be improved and the trajectory of the golf ball can be predicted with higher accuracy.

The golf ball trajectory predicting apparatus of the present invention measures a golfer's swing using a test golf club, inputs the measured value of the swing, and predicts the head behavior when the target golf club is used, A calculation is performed based on the predicted value of the head behavior, the initial behavior of the golf ball after colliding with the head is calculated, and the trajectory of the golf ball is predicted from the calculated initial behavior of the golf ball. To do.
With the above configuration, it is possible to accurately predict the trajectory of the golf ball.

Further, the golf club selection method of the present invention is characterized in that the golf club is selected from the trajectory of the golf ball predicted by the golf club selection method of the present invention.
With the above configuration, a suitable golf club can be selected.

  According to the present invention, it is possible to provide a trajectory predicting method for a golf ball and a trajectory predicting device for a golf ball, which can predict the trajectory of a golf ball with high accuracy. Further, according to the present invention, it is possible to provide a golf club selection method capable of selecting a suitable golf club.

It is a flow figure for explaining the flow about one embodiment of the trajectory predicting method of the golf ball of the present invention.

Hereinafter, the present invention will be described in detail based on its embodiments.
(Golf ball trajectory prediction method)
First, an embodiment of a golf ball trajectory prediction method according to the present invention will be described.
As shown in FIG. 1, the golf ball trajectory prediction method of the present invention includes a swing measurement step (FIG. 1A) of measuring a swing of a golfer using a test golf club.
A head behavior prediction step (FIG. 1(b)) of predicting the behavior of the head of the golf club when the target golf club is used, using the measured value of the swing obtained in the swing measurement step as an input;
A ball initial behavior calculation step of performing calculation based on the predicted value of the behavior of the head of the golf club obtained in the head behavior prediction step and calculating the initial behavior of the golf ball after colliding with the head (FIG. 1 ( c)) and
A ball trajectory predicting step (FIG. 1(d)) for predicting the trajectory of the golf ball from the initial behavior of the golf ball calculated in the ball initial behavior calculating step.
According to the present invention, the trajectory of the golf ball can be predicted with high accuracy by including the above configuration.

When a golf club selects a golf club, what flight path the golfer follows when hitting the golf club, that is, the ball trajectory is the most important information. This ball trajectory can be theoretically calculated from the initial behavior of the golf ball immediately after launch. Therefore, in order to obtain the trajectory information, it is important to understand the initial behavior of the golf ball.
Usually, it is common to actually hit a ball with a target golf club, and to grasp the initial ball behavior by measuring the initial ball behavior immediately after launch with a measuring machine. However, it is difficult to compare many clubs under the same conditions because the number of clubs that can actually be tried is physically and temporally limited and there are variations in the swings of people. ..
Therefore, a method is used in which the optimum one is selected from many target clubs by calculating a case where a plurality of target clubs are used on a computer by using computer simulation and using the calculated result as a fitting index. .. Here, the computer simulation is divided into two steps. A swing simulation process (head behavior prediction process) that calculates the head behavior by inputting human swing characteristics, and a collision simulation process (ball initial behavior calculation process) that predicts the initial behavior of the ball from the head behavior at the time of impact (entry condition). ).
Accordingly, the present invention calculates the initial behavior of the golf ball after it has collided with the head by calculating the finite element method or a regression equation obtained from the finite element method, thereby accurately predicting the initial behavior of the golf ball. As a result, it becomes possible to accurately predict the trajectory of the golf ball.

Swing Measurement Step The golf ball trajectory prediction method of the present invention includes a swing measurement step of measuring a golfer's swing using a test golf club, as shown in FIG.
This swing measurement step is a step of measuring the input data for performing the swing simulation with an arbitrary measuring device.

  As described above, the golfer's swing is performed using a test golf club. Even when the conditions of the golf club or the golf ball are changed, it can be predicted by calculation, so that it is possible to reduce the number of swings and the labor required for changing the golf club and the like.

  The test golf club is not particularly limited as long as its physical properties are known. A golf club prepared by a golfer can be used as the test golf club, but in that case, it is desirable to perform a swing simulation reflecting the physical characteristics of the golf club prepared by the golfer.

The swing measurement value obtained in the swing measurement step is not particularly limited as long as it is a measurement method capable of measuring the swing characteristics of the golfer.
For example, it is preferable that the data is acceleration data or three-dimensional coordinate data of the grip portion acquired by using an acceleration sensor or motion capture.
The measurement conditions of the acceleration sensor and the motion capture are not particularly limited, and desired swing data can be acquired by appropriately adjusting.

  In the swing measurement step, it is preferable to further measure the initial behavior of the golf ball hit by the swing (FIG. 1(e)). This is because the measured initial behavior of the golf ball is used to correct the calculation result obtained by the regression equation described later. It should be noted that the initial behavior of the golf ball in the swing measurement step is measured for each golfer, and since it is the data acquisition for the correction described later, it is not necessary to measure it again after the correction.

-Measurement of Meat Ratio and Comparison with Threshold As shown in FIG. 1(h), the golf ball trajectory prediction method of the present invention further measures the meat ratio at the time of the swing measurement so that the meat ratio is a predetermined value. Check if it is above the threshold. Then, it is preferable to use only the swing in which the meet rate is equal to or more than the threshold value as an input in the head behavior prediction step described later.
When the head of the golf club and the ball collide with each other in an ideal manner, the meet rate increases. Therefore, the meat rate can be used as an index of an ideal collision. By using only the swing measurement in which the meet rate is equal to or more than the threshold value as an input, the swing measurement in the case of a mishit can be excluded, and the initial behavior of the golf ball can be calculated more accurately. For example, when the driver's swing is measured using "Trackman" manufactured by TRACMAN, the threshold value of the meet rate may be 1.4 or more, and a golfer who can collide fairly accurately may have a threshold value of 1.45 or more. Note that the meet rate may not reach 1.4 or higher depending on the measuring instrument or club used, and in that case, it is desirable to review the threshold appropriately.

  The meet rate is the initial speed of the ball hit (the initial speed of the ball/the head speed) with respect to the head speed at the moment of impact. The method of acquiring the meat rate is not particularly limited, and it can be obtained by measuring the head speed at the moment of impact and the initial speed of the ball hit by a commercially available measuring instrument or the like.

Head Behavior Predicting Step In the golf ball trajectory predicting method of the present invention, after the above-described swing measuring step, as shown in FIG. 1B, when the target golf club is used with the measured value of the swing as an input. And a step of predicting the head behavior of (head behavior predicting step).
In this head behavior prediction step, the "head behavior" that is the input value (explanatory variable) of the regression equation used in the ball initial behavior calculation step (FIG. 1C) described later is predicted by calculation from the measured value of the swing. It is a process to do.

  Here, the behavior of the head is the entry condition of the head immediately before the impact with respect to the golf ball, and for example, the attitude angle (θ) and the velocity vector (v) of the head of the golf club are Can be mentioned. In addition, necessary parameters can be appropriately predicted so as to be input values of the regression equation described later.

Further, when predicting the head behavior, the shaft of the golf club of interest is compared with the swing measurement value of the test golf club so that the head behavior of the golf club of interest can be predicted. Also, the prediction is performed in consideration of the head information. Here, the information of the shaft and head of the target golf club is bending rigidity (EI), torsional rigidity, weight, length, etc. of the shaft of the golf club. In the golf club head, the center of gravity position, loft angle, etc. , Lie angle, etc., and calculation is performed using a golf club model that reflects them.
Here, the target golf club is a golf club for which the trajectory of the golf ball is to be predicted.

  The head behavior can be predicted by calculation using a computer with the measured value of the swing as an input value. For example, a method of simulating the head behavior by using the measured value of the swing as an input value and calculating the attitude angle (θ) and the velocity vector (v) of the head can be used.

Ball Initial Behavior Calculating Step The golf ball trajectory predicting method of the present invention is, as shown in FIG. 1C, after the head behavior predicting step described above, the behavior of the head of the golf club obtained in the head behavior predicting step. And a step of calculating the initial behavior of the golf ball after the collision with the head (ball initial behavior calculation step).
This ball initial behavior calculation step is a step of calculating the initial behavior of the golf ball after it has collided with the head by the motion analysis by the finite element method and the calculation of the regression equation prepared in advance, and the accurate initial behavior of the golf ball. Can be obtained.

  Here, the initial behavior of the golf ball is a state of the golf ball after colliding with the head of the golf club, and the trajectory of the golf ball is predicted based on the initial behavior of the golf ball. The initial behavior of the golf ball is not particularly limited, and various parameters can be adopted as the initial behavior, but the initial speed, the launch angle, and the spin amount after the collision with the head of the golf club are possible. preferable. These parameters are factors that greatly affect the trajectory of the golf ball, and the trajectory of the golf ball can be predicted with high accuracy by using these parameters as the initial behavior.

  Further, for the calculation for calculating the initial behavior of the golf ball, it is preferable to use a regression equation in which the predicted value of the head behavior is input. When calculating the initial behavior of a golf ball after it is hit by a collision simulation such as the finite element method, there is a problem that the simulation time becomes long with the current computer resources. Therefore, it is desirable to previously calculate the ball behavior after collision by inputting various head behaviors by the finite element method or the like, and obtain the regression equation of the head behavior and the initial ball behavior. This is because by calculating the initial behavior of the golf ball using this regression equation, the time required for the calculation can be significantly shortened as compared with the case where a simulation such as the finite element method is used. It should be noted that, in general, approximating such a complicated calculation with a regression formula leads to a decrease in prediction accuracy, but by setting a threshold value for the above-mentioned meet rate, it is limited within a range where the regression formula fits well. Calculations can be made.

For the calculation for calculating the initial behavior of the golf ball, it is possible to use the collision analysis by the finite element method with the predicted value of the head behavior as an input. This is because although the calculation takes time, the initial behavior of the golf ball can be calculated more accurately. The collision analysis is a motion analysis before and after a collision between the head of the golf club and the ball.
The finite element method (FEM) is one of numerical analysis methods, and divides an area in which equations are defined into small areas (elements) and approximates the equations in each small area with a common complementary function. Thus, it is possible to numerically obtain an approximate solution of a differential equation that is difficult to analyze.
When the finite element method is used to predict the initial behavior of the golf ball, for example, the head of the golf club that collides with the golf ball is divided into small regions and analyzed to analyze the initial behavior of the golf ball (for example, collision). The initial velocity, spin amount, etc.) can be numerically obtained.

Here, examples of the regression equation include the following equation (1).
Y=αX+β (1)
In the equation, Y is the launch angle (angle formed by the ball flight line and the ground plane), α is a proportional constant (for example, about 0.9±0.1), and X is the angle formed by the head face surface with the ground plane (dynamic loft). , Β are proportional constants (values such as −0.3).

Furthermore, regarding the regression formula and the calculation result using the kinematic analysis by the finite element method, the difference between the calculated initial behavior of the golf ball and the measured initial behavior of the golf ball is compared, and depending on the comparison result, It is preferable to perform the correction by This is because the accuracy of calculation can be improved and the trajectory of the golf ball can be predicted with higher accuracy.
As shown in FIG. 1, in the swing measurement step (FIG. 1(a)), the initial behavior of the hit golf ball is also actually measured (FIG. 1(e)), and then the measured initial golf ball is moved. The behavior is compared with the calculated initial behavior of the golf ball (FIG. 1(f)), and correction is performed based on the comparison result (FIG. 1(g)).

  Further, the method of correcting the calculation is not particularly limited as long as it can improve the accuracy of the calculation, but for the reason that the accuracy of the calculation can be easily and surely increased, the actually measured golf ball is used. It is more preferable to perform offset correction in which a difference from the initial behavior of the ball is directly added to the calculated initial behavior of the golf ball.

Here, the offset correction will be described in detail.
The initial behavior of the ball obtained by the calculation includes an error (hereinafter referred to as an error X) to some extent. The factors of the error X are various and cannot be generally specified, but examples thereof include a measurement error at the time of swing measurement and a shift of an impact hit point.
In order for the golfer to select a club, the relative difference between the clubs is important, and how the trajectory changes when the original reference club is changed to the target club is important. In the present invention, the original reference club is the test club. Therefore, the difference between the ball initial condition obtained by simulation and calculation using a club model corresponding to the test club and the actual ball initial behavior actually measured using the test club is obtained. This difference corresponds to the error X.
Next, the difference is added (or subtracted) to the initial ball behavior obtained by simulation and calculation for various target clubs. By making such a correction, it is possible to obtain a relative difference in how the trajectory changes when the target club is used with respect to the actual trajectory, and to inform the golfer of the result in a more understandable manner. You can

-Ball trajectory predicting step In the golf ball trajectory predicting method of the present invention, after the ball initial behavior calculating step described above, as shown in FIG. 1D, the initial behavior of the golf ball calculated in the ball initial behavior calculating step. From the above, a step of predicting the trajectory of the golf ball (a trajectory prediction step of the golf ball) is provided.
The ball trajectory predicting step is a step of predicting by calculation, based on the calculated initial behavior of the golf ball, the trajectory of the hit ball hit from the target golf club. Here, the trajectory may be visual data describing the trajectory, or may be numerical data such as flight distance, left/right deviation, angle at launch and landing, height of trajectory, etc. It may be.

The method of predicting the trajectory of the golf ball is not particularly limited, and a known prediction method can be used.
For example, there is a method of deriving a motion element of the golf ball by a computer calculation from the calculated initial behavior of the golf ball to simulate a trajectory.

(Golf ball trajectory prediction device)
Next, an embodiment of the golf ball trajectory predicting apparatus of the present invention will be described.
The golf ball trajectory predicting apparatus of the present invention measures a golfer's swing using a test golf club, and inputs the measured value of the swing to the head of the golf club when the target golf club is used. Predict the behavior, calculate based on the predicted value of the head behavior, calculate the initial behavior of the golf ball after colliding with the head, and predict the trajectory of the golf ball from the calculated initial behavior of the golf ball It is characterized by doing.
With the above configuration, the trajectory of the golf ball can be predicted with high accuracy.

Further, the golf ball trajectory predicting apparatus further measures a meat rate during the swing measurement, and in the head behavior prediction, among the measured swings, only the swing in which the meat rate is equal to or more than a predetermined threshold value is used. It is preferably used as input.
The reason why only the swing having the meet rate equal to or higher than the threshold value is used as the input, the suitable threshold value, and the like are as described above.

Here, the golfer's swing measurement is not particularly limited. For example, the above-described acceleration sensor or motion capture can be used.
Also, the measurement of the meet rate is not particularly limited, and for example, the head speed at the moment of the impact and the initial speed of the shot ball are measured using a measuring device such as a high-speed camera, and obtained by calculation. Alternatively, a commercially available meat rate measuring device can be used.
Furthermore, the prediction of the head behavior is also not particularly limited, and it can be performed using a computer incorporating commercially available simulation software.
The initial behavior of the golf ball can be calculated by using a computer incorporating a specific regression equation or motion analysis software by the finite element method.
Furthermore, the trajectory prediction of the ruffball is not particularly limited, and it can be performed using a computer incorporating commercially available simulation software.

  The details of other elements constituting the golf ball trajectory predicting apparatus of the present invention are the same as those described in the above-described golf ball trajectory predicting method of the present invention.

(How to select a golf club)
Next, an embodiment of the golf club selection method of the present invention will be described.
The golf club selection method of the present invention is characterized in that a golf club is selected from the trajectory of the golf ball predicted by the above-described golf ball trajectory prediction method.
With the above configuration, a suitable golf club can be selected based on the accurately predicted trajectory of the golf ball.
For example, a golfer can select his or her favorite club by referring to an image showing a predicted trajectory and prediction data of flight distance, launch and landing angle, or trajectory height. Further, retailers and manufacturers can also select and recommend the most suitable golf club to the golfer based on the predicted trajectory.

  According to the present invention, it is possible to provide a golf ball trajectory predicting method and a golf ball trajectory predicting apparatus capable of predicting the trajectory of a golf ball with high accuracy. Further, it becomes possible to provide a golf club selection method capable of selecting a suitable golf club.

Claims (6)

A swing measurement step of measuring acceleration data and/or three-dimensional coordinate data of a grip portion when a golfer swings using a golf club for a test,
The attitude value (θ) and/or the velocity vector (v) of the head, which is the behavior of the head of the golf club when the target golf club is used, with the measured value during the swing obtained in the swing measurement step as an input ) Of the head behavior prediction step,
After performing a calculation based on the predicted value of the behavior of the head of the golf club obtained in the head behavior prediction step, which is the initial behavior of the golf ball after the collision with the head, after the collision with the head of the golf club, A ball initial behavior calculation step of calculating initial velocity, launch angle and spin amount;
From the initial behavior of the golf ball calculated in the ball initial behavior calculation step, the movement element of the golf ball is derived by calculation by a computer, and the trajectory of the golf ball is predicted.
In the swing measurement step, further, during the swing, the meet rate, which is the initial speed of the ball hit against the head speed of the golf club at the moment of impact, is measured, and in the head behavior prediction step, in the swing measurement step. Among the measured swings, a golf ball trajectory predicting method is characterized in that only measured values of swings in which the meet rate is equal to or higher than a predetermined threshold value are used as inputs. In the swing measurement step, the initial behavior of the golf ball due to the swing is further measured,
The initial behavior of the golf ball measured in the swing measurement step is compared with the initial behavior of the golf ball calculated in the ball initial behavior calculation step to correct the calculation result based on the predicted value of the head behavior. The trajectory predicting method for a golf ball according to claim 1, wherein:   The trajectory of the golf ball according to claim 1 or 2, wherein the initial behavior of the golf ball is calculated from a collision analysis by a finite element method using a predicted value of the behavior of the head of the golf club as an input. Prediction method.   The golf ball trajectory prediction method according to claim 1, wherein the threshold value of the meet rate is set to 1.4 or more.   The initial behavior of the golf ball is calculated by using a regression equation of a head behavior and a ball initial behavior prepared in advance, using a predicted value of the behavior of the head of the golf club as an input. The golf ball trajectory prediction method described. When swinging a golfer using a test golf club, measure acceleration data and/or three-dimensional coordinate data of the grip portion,
Using the measured value of the swing as an input, predicting the attitude angle (θ) and/or the velocity vector (v) of the head, which is the behavior of the head of the golf club when the target golf club is used,
Performing calculation based on the predicted value of the head behavior, which is the initial behavior of the golf ball after colliding with the head, after collision with the head of the golf club, initial velocity, launch angle and spin amount,
From the calculated initial behavior of the golf ball, the movement element of the golf ball is derived by calculation by a computer, and the trajectory of the golf ball is predicted,
In the measurement of the swing, further, during the swing, the meet rate, which is the initial speed of the ball hit against the head speed of the golf club at the moment of impact, is measured, and in the prediction of the head behavior, the measured swing Among them, a trajectory predicting device for a golf ball, wherein only a measured value of a swing in which the meet rate is equal to or more than a predetermined threshold value is used as an input.

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