JPH0576634A - Golf practice machine - Google Patents

Abstract

PURPOSE:To provide a golf practice machine which can correctly grasp the positional relationship of the position of feet of a subject and measurement information on the center of load. CONSTITUTION:A swing base 1 comprises plural load measuring bases 10, 11 independently including a load detecting sensor D in order to detect the center of load corresponding to right and left feet of a subject, respectively. In a golf practice machine, there is provided a footprint detecting means for detecting the footprint of a subject and the position of the footprint on the swing base according to the detection information of the load detecting sensors D of the load measuring bases 10, 11, and a display means 4 displays storage information during driving operation and the footprint detected by the footprint detecting means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swing table provided with a load detecting sensor, on which a subject who holds a club and hits a ball is placed, and a load or load applied to the swing table based on the detection information of the load detecting sensor. Measuring means for measuring the center, storage means for sampling the measurement information of the measuring means at regular intervals and sequentially storing the data, and display for displaying the storage information during the ball striking operation based on the storage information of the storage means And a golf training machine provided with means.

[0002]

2. Description of the Related Art Conventionally, in such a golf practice machine, when a subject hits a ball on a swing table, the position on the swing table and the measurement information of the measuring means are associated with each other so that the position on the swing table is associated with the position. According to the mark provided in advance, a stance was taken and a ball was hit.

[0003]

Generally, when the measurement information such as the center of load during the ball hitting motion of the subject is displayed, clarifying the positional relationship of the measurement information enables more accurate analysis of the measurement information. You can Traditionally, because of this,
As mentioned above, when taking a stance, it was always aligned with the mark position. However, the desired stance for performing a ball striking action is usually different depending on the individual difference of the club used and the subject, and even if the position and width of the stance are changed according to the club used by the subject,
In the past, the device side could not detect this and always displayed the measurement information as if it had the same stance. The present invention has been made in view of the above circumstances, and an object thereof is to accurately grasp the positional relationship between the position of the foot and the measurement information, even if the position where the subject stands and the stance are freely changed. It is to provide a golf training machine that can

[0004]

SUMMARY OF THE INVENTION A golf training machine according to the present invention mounts a subject who grips a club and hits a ball, and mounts a swing table having a load detection sensor, and the swing based on detection information of the load detection sensor. Measuring means for measuring the load or load center applied to the table, storage means for sampling the measurement information of the measuring means at regular intervals and sequentially storing the data, and a hitting operation during the ball hitting operation based on the storage information of the storage means. Display means for displaying stored information is provided, and the first characteristic configuration is that the swing platform independently detects the load center so that the swing table can detect the load centers corresponding to the left and right feet of the subject. Consisting of a plurality of load measuring bases, based on the detection information of the load detecting sensor of the plurality of load measuring bases, the foot shape of the subject and the foot shape on the swing base. Position footprints detecting means for detecting are provided, the display means, the stored information in the hitting operation, in that it is configured to display a footprint that is detected by the footprint detecting means. A second characteristic configuration is that the display means is configured to display the memory information during the ball hitting motion as a two-dimensional trajectory and to display the foot shape on the trajectory. A third characteristic configuration is configured such that the measuring unit measures a load center corresponding to each of the left and right feet of the subject based on the detection information of the load detection sensors of the plurality of load measuring bases, The storage means is configured to store the load center corresponding to each of the left and right feet of the subject, the display means, based on the storage information of the storage means, for each of the left and right feet of the subject during the ball striking motion. The point is configured to display the corresponding load center. In the fourth characteristic configuration, command means for instructing foot shape detection is provided, and the foot shape detecting means detects when the subject moves the center of gravity of the body back and forth in accordance with the foot shape detection being instructed by the command means. Based on the detection information of the load detection sensor of the plurality of load measuring table, the straight line connecting the toe side load center corresponding point and the heel side load center corresponding point of each of the left and right feet is calculated, and this is calculated. An area in which a predetermined width is added in both lateral and front-rear directions of the straight line is configured to be detected as the foot shape. In a fifth characteristic configuration, the foot shape detecting means obtains a straight line from the detection information of the load detecting sensor by a straight line approximation method, and on this straight line, the maximum value of the load center data of each of the left and right feet in the front and rear direction of the foot and The point corresponding to the minimum value is the point corresponding to the toe side load center and the point corresponding to the heel side load center, and the straight line connecting these load center corresponding points is the straight line. In a sixth characteristic configuration, the foot shape detecting means calculates a maximum value and a minimum value in the front-rear direction of the load center data of each of the left and right feet from the detection information of the load detecting sensor, and the maximum value and the minimum value are calculated. The point corresponding to the toe side load center and the heel side load center correspond to each other, and the straight line connecting these load center correspondent points is the straight line.

[0005]

According to the first characteristic configuration, the foot shape detecting means is based on the detection information of the load detecting sensors of the plurality of load measuring tables,
For example, the foot shape and the position of the foot shape of the subject are detected based on the movement loci of the load centers corresponding to the left and right feet when the subject swings the body in the front-back direction. Further, the load and the measurement information of the load center measured by the measuring means during the ball hitting operation are stored in the storage device. Then, for example, on the display means such as a graphic display device, the stored information during the ball striking motion stored in the storage means is displayed together with the foot shape. According to the second characteristic configuration, when the display means such as a graphic display device displays based on the storage information of the storage means, the storage information during the ball hitting operation, for example, the storage information of the load center is a two-dimensional locus. Is displayed together with the foot shape. According to the third characteristic configuration, the measuring means measures the load center during the ball striking motion corresponding to each of the left and right feet of the subject, and the measurement information is stored in the storage means. And
The display means, based on the storage information of the storage means, the load center corresponding to each of the left and right feet together with the foot shape, or
It is displayed together with the foot shape and the two-dimensional trajectory. According to the fourth characteristic configuration, for example, the left and right feet are detected based on the detection information of the load detection sensor that is detected when the subject moves the center of gravity of the body back and forth in accordance with the instruction to detect the foot shape by the command unit. A straight line connecting each toe-side load center-corresponding point and the heel-side load center-corresponding point is calculated, and a region in which a predetermined width is added in both lateral and front-rear directions of the calculated straight line is detected as a footstep. .. According to the fifth characteristic configuration, a straight line is obtained from the detection information of the load detection sensor by a straight line approximation method, and on this straight line, the maximum and minimum values of the load center data of the left and right feet in the anteroposterior direction of the foot are corresponded. The points to be performed are the toe side load center equivalent point and the heel side load center equivalent point, and the straight line connecting these load center equivalent points is detected as the straight line. According to the sixth characteristic configuration,
The maximum value and the minimum value in the front-back direction of the foot of the load center data of each of the left and right feet are calculated, and the maximum value and the minimum value are set as the toe side load center equivalent point and the heel side load center equivalent point, and these loads A straight line connecting the central points is detected as the straight line.

[0006]

According to the first characteristic configuration, the position where the foot is actually placed and the actual foot shape are detected and displayed on a display device such as a graphic display device together with the measurement information of the load or the load center. Therefore, even if the position or stance of the subject is freely changed, the positional relationship between the foot position and the measurement information can be accurately grasped. According to the second characteristic configuration, the position where the foot is actually placed and the actual foot shape are detected, and, for example, the measurement information of the load center is displayed as a two-dimensional locus on a display device such as a graphic display device. Therefore, it is possible to accurately grasp the positional relationship between the position of the foot and the measurement information. According to the third characteristic configuration, the center of load corresponding to each of the left and right feet of the subject is displayed on the display device such as a graphic display device together with the foot shape or the foot shape and the two-dimensional trajectory, so that the left and right feet of each of the left and right feet are displayed. The positional relationship between the foot shape and the load center of each of the left and right feet can be accurately grasped, and it has become possible to perform a more detailed analysis of the movement of the subject's weight. According to the fourth characteristic configuration, the toe side load center equivalent point and the heel side load center equivalent point are accurately obtained by the foot shape detecting means, and thus the toe side load center equivalent point and the heel side load center equivalent point are determined. By adding a predetermined width to the connecting straight line, it becomes possible to detect the foot shape corresponding to the actual foot shape. According to the fifth characteristic configuration, the straight line connecting the toe-side load center corresponding point and the heel-side load center corresponding point can be accurately obtained by the linear approximation method. According to the sixth characteristic configuration, it is possible to obtain the straight line connecting the toe side load center corresponding point and the heel side load center corresponding point by a simple calculation.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the golf training machine of the present invention will be described below with reference to the drawings. 1, 2 and 3, 1
Is a swing stand, 2 is a tea stand, 3 is a processing device, 4
Is a display device as display means. The golf training machine of the present embodiment processes the detection data of the load detection sensor D provided on the swing table 1 by the processing device 3 during the ball hitting motion,
It is temporarily stored as time-series data of load or load center and is displayed after the ball hitting operation is completed. Hereinafter, each device will be described.

The swing base 1 is composed of two load measuring bases 10 and 11 corresponding to the left and right feet respectively, and the load measuring base 10 of the left foot is composed of four load cells 1 as load detecting sensors D.
The four corners are supported by 2, 13, 14, and 15,
The load measuring table 11 of the right foot is supported at four corners by four load cells 16, 17, 18, 19 as the load detecting sensor D. On the swing table 1, the subject holding the club C performs a ball hitting motion. At this time, the load applied to the swing base 1 is the eight load cells 12, 13, 14, 15, 16, 1 supporting the two load measurement bases 10, 11.
7, 18, and 19 share the load and the load center of the subject and the load centers corresponding to the left and right feet of the subject, as will be described later.

A mounting tool 25 for mounting a ball 24 is mounted on the tea stand 2. Then, a reflection type that detects the presence or absence of the ball 24 on the other side of the club head passage at the position where the ball 24 is set, functions as a reset switch when starting a new ball hitting action, and detects a time point equivalent to the ball hitting. An optical sensor 21 is provided, and at the club head passing position on the backswing side, there is provided a club detection means 22 composed of a reflection type optical sensor installed in the same manner as above to detect the movement of the club C to the backswing side. ing.
The control box 26 has a built-in drive circuit for the reflection type optical sensor 21 and the club detecting means 22.

The processing device 3 includes a calculation processing means 31 for performing a calculation process for obtaining a load and a load center and a sequence control of the device, an I / O interface 32 for transferring various data, a load and a load center measurement information. The storage device 33 is a storage device for storing the data, a command device 34 for selecting the operation mode of the device and inputting various comments, an external storage device 35 for storing measurement information and the like. The display device 4 is composed of a graphic display device 41 and a plotter 42. The graphic display device 41 displays the movement locus of the load center, and the plotter 42 displays the time change of the load, but both displays can be switched. Is.

Next, the process of obtaining the load and the load center will be described. The test subject who holds the club C stands in a substantially center position on the swing table 1 by standing with the left and right feet on the two load measuring tables 10 and 11, respectively. Taking the load measuring table 10 on which the subject places his left foot as an example, the load cells 12, 1 at the four corners of the load measuring table 10 will be described.
For the outputs of 3, 14 and 15, the stand load is canceled in advance by zero adjustment in the load converter 16,
The total WL of the outputs W1, W2, W3, and W4 becomes the load of the left foot of the subject on the load measuring table 10. That is, WL = W1 + W2 + W3 + W4 Furthermore, at this time, since the shared output of each load cell differs depending on the relationship between the position to which the load is applied and the installation position of the four load cells 12 to 15, the load applied to the load measuring table 10 from these outputs. You can seek the center.
That is, the load component in the left-right direction X and the front-rear direction component Y of the load center expressed with the load cell 12 in FIG. 1 as the origin is a rectangle in which the four load cells 12 to 15 have the width a in the X direction and the width b in the Y direction. When the load measuring table 10 is arranged at the four corners, it can be calculated from X = (W2 + W3) × a / WL Y = (W3 + W4) × b / WL. In addition, the load cells 12, 13,
Even when the arrangements of 14 and 15 are not at the four corners of the rectangle, the load center can be obtained by performing the correction unique to the geometrical arrangement of the load cells. If three or more load cells are provided, the center of the load applied to the swing table 1 can be obtained. The load measuring table 11 on which the subject places his right foot is also configured the same as the load measuring table 10,
The load center of the load applied to the load measuring table 11 can be obtained in the same manner as described above. Regarding the load and center of the load on both legs of the subject, that is, the load center, assuming that the load applied to the load measuring table 11 is WR, from the outputs W5 to W8 of the load cells 16 to 19, WR = W5 + W6 + W7 + W8 The load WT of the whole body is obtained by WT = WL + WR, and the load center is a line segment connecting the left and right load centers, where L is the distance between the load center corresponding to the subject's left foot and the load center corresponding to the right foot. In the above, it is located at a position WR × L / WT away from the load center corresponding to the left foot, and this may be calculated.

As shown in FIG. 3, eight load cells 12 ...
Outputs W1 to W4 and W5 to W8 of 15 and 16 to 19
Is a load converter 16 equipped with a measurement bridge circuit and an A / D converter, and after compensating for the weight of the swing table 1 as described above,
A digital amount is sampled at regular intervals.
Then, it is sequentially loaded into the processing device 3 via the I / O interface 32. The load WT of the subject, the load center, and the load centers corresponding to each of the left and right feet are obtained by the arithmetic processing means 31 in the processing device 3 according to the above-described formula. Then, the obtained load and time series data of the load center are temporarily stored in the storage device 33. Therefore, the arithmetic processing means 31 controls the load applied to the swing base 1 or the load center,
It also functions as a measuring means S for measuring the load centers corresponding to the left and right feet, respectively.

Next, the process in which the arithmetic processing means 31 functioning as the foot shape detecting means F detects the foot shape of the subject will be described. When the test subject puts his left and right feet on the two load measuring tables 10 and 11 and stands on the swing table 1 and swings his / her body forward and backward, as shown in FIG. 4, the left and right feet respectively move from the toes to the heels. The load centers of the left and right feet move along the loci 51 and 52 as shown in FIG. The arithmetic processing means 31 obtains a straight line from the load center value data by a linear approximation method such as the least square method or Hough transform, and the maximum value 53 in the front-back direction of the load center data of each of the left and right feet on this straight line. , 55 corresponding to the toe side load center corresponding points H, J as shown in FIG.
Then, the points corresponding to the minimum values 54 and 56 are set as heel side load center corresponding points I and K, and a straight line 61 connecting the load center corresponding points H and I and a straight line 62 connecting J and K are obtained. Further, the arithmetic processing means 31 detects a region in which a predetermined width is added in both lateral and front-rear directions of the straight lines 61 and 62 as footsteps 63 and 64, and the position of the footstep on the swing base 1 is It is configured to detect corresponding to each of the left and right feet.
The foot shapes 63 and 64 are specifically determined as follows. As shown in FIG. 5, the left and right foot widths 65 are determined according to the lengths of the straight lines 61 and 62 so that the longer the length, the wider the foot width. The area of the foot in the left-right direction is determined, the foot width in the front-rear direction is set to the same width as the foot width 65 in the left-right direction, and the center points corresponding to the load centers H, I, J, K are drawn. The radius of the foot defines an area in the front-rear direction of the foot with an arc of the foot width 65.

Further, the arithmetic processing means 31 can also obtain the straight lines 61 and 62 as follows and detect the foot shapes 63 and 64 as described above based on these straight lines. Maximum value 53 in the front-back direction of the load center data for each of the left and right feet,
55 is the toe-side load center equivalent point H, J, and the minimum value 54,
A straight line 61 connecting H and I and a straight line 62 connecting J and K are obtained with 56 as the heel side load center corresponding points I and K.

The operation of this device in use will be described below with reference to the flowchart of FIG. In the flowchart of FIG. 6, after the power switch (not shown) is turned on to start the device, the command means 34 sets the operation mode of the device. The operation modes include two modes: a foot shape display mode in which the foot shape is detected by the foot shape detecting means F and the detected foot shape is displayed on the graphic display device 41, and a non-display mode in which the foot shape is not detected and displayed. When the operation mode has been set and the operation mode is not set to the footstep display mode, the next mounting tool 2
If the foot shape display mode is set, the position of the subject's foot shape and foot shape on the swing table 1 is detected and the graphic display device 41 is detected. Is displayed, and the process proceeds to the position where the presence or absence of the ball 24 on the mounting tool 25 is detected. With the reflective optical sensor 21,
It is detected whether the ball 24 is placed on the mounting tool 25, and if the ball 24 is not on the mounting tool 25, the detection data of the load detection sensor D is fetched and arithmetically processed to determine the load center of the entire body. And the load center corresponding to each of the left and right feet is obtained, and screen control is performed so as to display points on the graphic display device 41 in dots. After the screen control is performed, if the mode change switch of the command means 34 is pressed, the process returns to before the operation mode is set, and if not pressed, the position where the presence or absence of the ball 24 is detected is returned to.

When the ball 24 is placed on the placing tool 25, the screen of the graphic display device 41 and the previously stored data are cleared. Then, the detection data of the load detection sensor D is fetched, the load and the load center of the entire body, and the load centers corresponding to the left and right feet are obtained by the arithmetic processing and stored in the storage device 33. The calculation results of the load center are displayed as points on the graphic display device 41. afterwards,
If the ball striking motion is not finished yet, the load detection sensor D
Return to the detection data acquisition position of. If the hitting motion is completed, that is, if the set time has elapsed from the time of hitting the ball, the movement locus 70 of the load center of the entire body and the movement of the load centers corresponding to the left and right feet as shown in FIG. Trail 7
1 and 72 are displayed on the graphic display device 41 together with the foot shapes 63 and 64, and the data of the time change of the whole body load as shown in FIG. 8 are displayed on the plotter 42. At this time, the data during the hitting motion is selectively displayed, but the club detecting means 22 detects the movement of the club to the backsunk side at the end except for the time immediately before the hitting ball is detected. Is detected as the ball hitting operation start time point, and the end time of the ball hitting operation is detected as the end time point after a set time has elapsed from the hitting ball equivalent time point detected by the reflective optical sensor 21 depending on the presence or absence of the ball 24. Then, it returns to the position where the presence or absence of the sphere 24 is detected.

[Other Embodiments] In the above embodiment, two load measuring bases are used, but two or more load measuring bases may be used, and a load detecting base for measuring the load of the whole body and the load center is separately provided, and the load is measured. You may arrange | position in two steps with the detection stands 10 and 11.
In the foot shape detecting means F of the above embodiment, the arithmetic processing means 3
1, the foot shapes 63, 64 are arranged such that an arc having a foot width of 65 as shown in FIG. 9 passes through the load center corresponding points H, I, J, K.
The area in the front-rear direction may be determined, or as shown in FIG. 10, a straight line with the foot width 65 provided above and below the load center equivalent points H, I, J, K is drawn to define the front-rear area of the foot shapes 63, 64. It may be determined, or as shown in FIG. 11, the load center equivalent point H,
Alternatively, a straight line passing through I, J, and K may be drawn to determine the front-back direction regions of the foot shapes 63 and 64. In addition, these FIG. 9, 10, 1
In FIG. 1, the right footstep is omitted and only the left footstep is described. In the footstep detecting means F of the above embodiment, the arithmetic processing means 31 obtains the straight lines 61 and 62 as follows,
The foot shapes 63 and 64 can be detected based on this straight line. The maximum values 53 and 55 in the front-rear direction of the load center data of the left and right feet are set to the toe side load center corresponding points H and J, and the minimum values 54 and 56 are set to the heel side load center corresponding points I and K and set to H. A straight line 61 connecting I and a straight line 62 connecting J and K are obtained. Instead of displaying the foot shape on the graphic display device 41 of the above embodiment, the straight line 6 obtained by the foot shape detecting means F is displayed.
1, 62 may be displayed. In the foot shape detecting means F of the above-described embodiment, the subject may swing the body not only in the front-back direction but also in the left-right direction, and obtain the width 65 of the foot from the movement locus of the load center at this time. Foot shape detecting means F of the above embodiment
In the method described in the embodiment, straight lines 61 and 62 are obtained from the load center data corresponding to the left and right feet during the ball hitting motion.
And the foot shape may be detected from this straight line. On the graphic display device 41 of the above-mentioned embodiment, the detection information or the measurement information of the foot shape, the load center of the whole body, and the load centers corresponding to the left and right feet respectively is displayed at the same time. Alternatively, an appropriate combination may be displayed. Similarly, although the time change of the load of the entire body is displayed on the plotter 42, the time change of the loads WL and WR corresponding to the left and right feet may be displayed. Each measurement information regarding the load and the load center of the above-described embodiment is stored in the external storage device 35 in the processing device 3 to store the measurement information, and read out as needed to be displayed on the display device 4. Is also good.

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a plan view of a golf training machine to which the present invention is applied.

FIG. 2 is a side view of a golf training machine to which the present invention is applied.

FIG. 3 is a block diagram of a golf training machine to which the present invention is applied.

FIG. 4 is an explanatory diagram of foot shape detection.

FIG. 5 is an explanatory diagram of foot shape detection.

FIG. 6 is a flowchart according to an embodiment to which the present invention is applied.

[Fig. 7] Display example of movement locus of load center

[Fig. 8] Display example of time change of load

FIG. 9 is an explanatory diagram of foot shape detection according to another embodiment.

FIG. 10 is an explanatory diagram of foot shape detection according to another embodiment.

FIG. 11 is an explanatory diagram of foot shape detection according to another embodiment.

[Explanation of symbols]

1 Swinging Table 4 Display Means 10 and 11 Load Measuring Table 33 Storage Means 34 Commanding Means 53 and 55 Maximum values of the load center data of the left and right feet in the front-back direction 54, 56 Foot of the load center data of the left and right feet Minimum value in the front-back direction 61,62 Straight line 63,64 Foot C club D Load detection sensor H, J Toe side load center equivalent point I, K Heel side load center equivalent point F Foot shape detecting means S Measuring means

Claims (6)

[Claims] 1. A swing base (1) having a load detection sensor (D) on which a subject who holds a club (C) and hits a ball is placed, and the swing based on detection information of the load detection sensor (D). Measuring means (S) for measuring the load or load center applied to the platform (1), storage means (33) for sampling the measurement information of the measuring means (S) at regular intervals and sequentially storing the data, and A golf practice machine provided with a display means (4) for displaying stored information during a ball striking motion based on the stored information of the storage means (33), wherein the swing table (1) has left and right feet of a subject. Each of the plurality of load measuring stands (10, 11) is equipped with a load detecting sensor (D) independently so as to detect the corresponding load center. Detection of load detection sensor (D) Footstep detection means (F) for detecting the footstep of the subject and the position of the footstep on the swing base based on the report, and the display means (4) stores the memory information during the ball hitting motion and the footstep. Foot shape (63, 64) detected by the detection means (F)
A golf practice aircraft configured to display and. 2. The display means (4) is configured to display the memory information during the ball hitting motion as a two-dimensional trajectory, and to display the foot shape on the trajectory. The listed golf training machine. 3. The load center corresponding to each of the left and right feet of the subject based on the detection information of the load detection sensors (D) of the plurality of load measuring stands (10, 11) by the measuring means (S). And the storage means (33) is configured to store the load center corresponding to each of the left and right feet of the subject, and the display means (4) is the storage means (33). 3. The golf training machine according to claim 1 or 2, wherein the center of the load corresponding to each of the left and right feet of the subject during the ball hitting motion is displayed based on the stored information in (3). 4. A command means (34) for commanding the detection of a footstep is provided, and the footstep detection means (F) allows the test subject to detect a footstep of the body as the footstep detection is instructed by the command means (34). Based on the detection information of the load detection sensors (D) of the plurality of load measurement bases (10, 11) that are detected when the center of gravity is moved back and forth, the toe side load center corresponding points (H, H, J) and a straight line (61,
62) is calculated, and the region obtained by adding a predetermined width in both lateral and front-rear direction of the calculated straight line (61, 62) is defined as the foot shape (63, 6).
4) configured to detect as 4).
In addition, the golf practice machine described in 3. 5. The foot shape detection means (F) obtains a straight line from the detection information of the load detection sensor (D) by a straight line approximation method, and on this straight line, the front and rear direction of the load center data of the left and right feet respectively. Maximum value (53,55) and minimum value (54,5)
6) is the point corresponding to the toe side load center (H,
J) and the heel side load center corresponding point (I, K), and a straight line connecting these load center corresponding points (H, J), (I, K) is set to the straight line (71, 72). The golf training machine according to claim 4, which is provided. 6. The maximum value (53, 55) and the minimum value (53, 55) and the minimum value (53, 55) in the front-rear direction of the load center data of each of the left and right feet are detected by the foot shape detection means (F) from the detection information of the load detection sensor (D). 54, 56) is calculated and this maximum value (53, 55) is calculated.
And the minimum value (54, 56) as the toe side load center corresponding point (H, J) and the heel side load center corresponding point (I, K), and these load center corresponding points (H, J), (I , K) is a straight line that connects the straight lines (71, 72).