JPH0355074A - Golf swing diagnosing machine - Google Patents

Abstract

PURPOSE:To measure the way of displacement of the center of gravity during a swing without a helper's aid and to judge whether an testee's swing is good or bad from a view point of the adequacy of movement of the center of gravity by providing a display device for indicating positions of the center of gravity in points of time of back-switching start and inpact. CONSTITUTION:A testee having a golf club stands on the nearly central portion of a load measuring stand 1 to hit a golf ball set on a tee in front of the stand for example. Measuring output signals of a load cell 15 are successively inputted and calculated during a period from a point of time of starting his back swing after addressing to a point of time of completing his swing with his swung-up club to figure out the displacement of the center of gravity and indicate the result on an indicator 4 constituted of a CRT, liquid crystal indicator, two-dimensional indicator such as plasma display or two-dimensional recorder such as plotter and printer. Whether the swing in the test is good or bad can be judged from the locus of the center of gravity indicated then.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a golf swing diagnosis that can diagnose a test subject's skill and use it as a guideline for improving the skill by visualizing and displaying the weight shift during the golf swing. Regarding machines.

[Conventional technology]

Although form is generally important in a golf swing, it is well known that movement of the center of gravity, so-called weight shift, is also an important factor.

Conventionally, movements during a swing are recorded on videotape and later played back repeatedly on a monitor television for analysis. In addition, by paying attention to the movement of the center of gravity from side to side, placing the left and right feet on load detectors and swinging, the movement status of the left and right load balance is displayed from the load measurement values measured at that time. Ta. Furthermore, a device for simultaneously outputting both on a television screen has been disclosed (Japanese Unexamined Patent Publication No. 62-44275).

By the way, most people believed that the weight shift during the golf swing was a linear movement between the right and left feet, but recent research has shown that from address to backswing, the center of gravity is located exactly in the center of both feet. However, from the downswing to impact, the center of gravity shifts toward the left foot while being slightly more on the toes than at address, so the trajectory of the center of gravity swells forward.
Later, the center of gravity shifted back again, and it became clear that it is best for the center of gravity at the moment of impact to be on the line connecting the centers of the left and right feet at the far left side of the trajectory. Situations such as sway and unsmooth weight shifting during the downswing, which are drawbacks of many golfers, can be resolved by capturing the movement of the center of gravity over time and projecting its trajectory on a flat surface.
Can be clearly observed. If you can train your golf swing so that the trajectory of the center of gravity obtained in this way matches the exemplary pattern described above, your golf ability will improve significantly.

Therefore, a device that determines and displays the locus of movement of the center of gravity during a swing becomes an effective swing diagnostic device, and an extremely useful swing practice aid for many golfers. However, since the swing analysis device can only capture one-dimensional left and right movement, it is not useful for determining the center of gravity trajectory. Currently, what is available for the above purpose is a system that can be analyzed by experts using advanced measurement and analysis equipment, and has not been used on a daily basis.

[Problem to be solved by the invention]

Therefore, it is an object of the present invention to provide a golf swing diagnostic device that measures the trajectory of the center of gravity of a subject during a golf swing and displays it two-dimensionally to help determine the quality of the swing. That's true. Another object of the present invention is to provide a golf swing diagnostic device that calculates and displays characteristic values representing the characteristics of the swing from the locus of the movement of the center of gravity during the golf swing, and easily and accurately diagnoses the quality of the swing.

[Means to solve the problem]

In order to solve the above problems, the first invention of the present application provides a load measuring table equipped with at least three load cells installed in the corners, a top plate on which a test subject is placed, a set position of a golf ball, and an address position of a club head. The golf swing diagnostic device is equipped with a head detector that detects the passing of a club head, and includes an arithmetic device that calculates the subject's center of gravity position from the load measurement output of the load cell of the load measurement table, and a computing device that calculates the center of gravity position of the subject from the load measurement output of the load cell of the load measurement table, and a trajectory of the center of gravity position. It is characterized by comprising a display device that displays a dimensional plane projection diagram and displays the center of gravity position at the start of the backswing and at the time of impact in the diagram.

Another aspect of the present invention is a golf swing diagnostic device including the load measuring table and the head detector, which is characterized in that it includes a display device that displays the subject's total load and center of gravity position at the time of impact. Furthermore, the present invention is characterized in that it includes a display device that continuously displays changes in the measured load before and after the impact time in a chronological manner, together with a marker indicating the impact time. In particular, it is characterized by being equipped with a display device that continuously displays the total load during the swing and the changes in the components of the center of gravity in the planar coordinate direction of both wheels.

The golf swing diagnostic device of the present invention further includes a calculation device that calculates characteristic values representing the characteristics of the test subject's swing from the trajectory of the center of gravity during the swing measured by the load measuring table, and a display device that displays the results. It may also be a configuration with the following.

Further, the golf swing diagnostic device of the present invention is provided with a storage device for recording the measurement results of the test subject's attempts, and is configured to overlay and display the records when measuring a new swing and displaying the results on the display device. It's fine.

[For production]

Since at least three load cells installed at the corners of the load measuring table serve as fulcrums of the top plate, a gravitational force proportional to the center of gravity of the load depending on the distance between the fulcrums is applied to the load cells. Therefore, by proportionally dividing each detection output inversely, the center position of the load applied to the table can be determined. At this time, if the load of the table itself is corrected, the center of gravity of the subject can be determined as projected onto a horizontal plane. The load and center of gravity position are determined by three load cells.
Although it can be calculated accurately, the calculation formula becomes slightly complicated and the stability of the top plate deteriorates. On the other hand, if the load cell is placed exactly at the four corners of a square and a table is placed on top of it, the position of the center of gravity projected onto the table can be calculated by simple proportional calculation using each output. is easily given. Furthermore, even if four load cells are arranged, their installation positions are not in accurate symmetrical positions, the initial load applied to each load cell is different, and the degree of output change when the load is applied is different. Also, by adjusting the output compensation value and weighting coefficient value given in advance, the correct projected position of the center of gravity can be found. Since this calculation is extremely easy for the mechanical calculation means provided in the calculation device,
Even when the subject moves on the table, the calculation results can be obtained almost in real time. Note that the term "load cell" here broadly refers to a load detection end, and does not necessarily have to be a strain gauge.

A subject holding a golf club stands approximately in the center of the load measuring table and is asked to hit a golf ball set on the tee in front of the table. At this time, from the time when you address and start the back swing until the end of the swing when you swing the club, the measurement output signal of the load cell is inputted sequentially, the above calculation is performed, the movement state of the center of gravity is calculated, and the result is CR
T, LCD display, plasma display, etc. 2
The image can be displayed on a display device composed of a dimensional display device or a two-dimensional recording device such as a plotter or printer.

The quality of the swing at the time of the attempt can be judged from the trajectory of the center of gravity displayed at this time, but when actually used for judgment, the part that appears as a result of the body movement before and after the swing movement, and the trajectory during the swing movement can be judged. Must be displayed separately.

If a person inputs a signal to start the swing at the right time to specify the part before the swing starts, an assistant must be present, as the swinging subject cannot operate the signal himself. This has the inconvenience of requiring .

The head detector included in the device of the present invention includes a transmission type or reflection type optical detector, an air back pressure measuring device,
A detector such as a magnetic sensor or a contact sensor is installed at the position of the club head at the time of addressing.
Since the movement of the club head is monitored, the starting point of the backswing can be accurately determined without manual intervention. With this signal, it is possible to write a symbol in the displayed trajectory or to distinguish the target trajectory portion by color. Furthermore, if the trajectory of the subject's center of gravity position determined by sequential calculations using the above method is displayed as a two-dimensional surface projection from this starting point, the trajectory before the swing is removed, and only the part related to the swing is displayed. It is preferable that a projected view of the movement trajectory of the center of gravity can be obtained, and the quality of the movement of the center of gravity especially at the beginning of the swing can be clearly evaluated.

At the pole set position on the head detector, a detector similar to the backswing detector described above is installed to detect the passing of the club head, and detects the time of impact. The center of gravity position is displayed in the center of gravity movement trajectory diagram. As mentioned earlier, the movement of the center of body weight at and around the time of impact is the most important indicator of the quality of the swing, so it is a function of the golf swing diagnostic machine to include the time of impact on the trajectory map. This greatly improves

The swing motion ends with the follow swing, and this follow swing also greatly influences the quality of the swing, but from the standpoint of determining the quality of the swing from the weight shift situation, it is sufficient to know the state up to the middle of the swing. be. Therefore, it is not necessary to know the exact point at which the follow swing ends, and the display of the trajectory diagram may be stopped at an appropriate time from the point of impact.

In addition, among the golf swing diagnostic machines equipped with the above-mentioned load measuring table and the above-mentioned head detector, the one that is characterized by displaying the subject's total load and center of gravity position at the time of impact is particularly suitable for displaying the subject's total load and center of gravity position at the time of impact. In,
The gravity fluctuation caused by the subject's movement is determined from the total load obtained by summing the measurement output of each load cell installed at the four corners of the load measurement table, corrected for its own weight, and the center of gravity position is calculated by proportionally dividing the total load. These can be displayed on a CRT or recorded on a plotter or the like. The output results of the device of the present invention are good indicators for swing diagnosis. In other words, as mentioned above, when making an optimal swing, it is best for the center of gravity at the moment of impact to be on the line connecting the centers of the left and right feet, and at the farthest left during the swing. .

Furthermore, during the swing, the total load measurement value fluctuates due to the acceleration of the center of gravity as the player moves up and down, and changes in the position of the center of gravity as a complex with the club head. Since it is known that the head speed is high, by looking at the output in one's own swing, it is possible to quantitatively know the deviation in impact timing, and it becomes possible to accurately correct the swing accordingly.

Furthermore, a marker that indicates the time of impact as well as a continuous display of changes in the measured load before and after the time of impact in chronological order allows you to know the changes before and after the impact as well as the data at the moment of impact, making it easy to diagnose the swing. It can also serve as more appropriate material for correction. In particular, those that continuously display the total load during swing and a certain amount of change in the planar coordinates of the center of gravity over time, and the changes in the center of gravity position are expressed over time by being broken down into two-axis segments. It is easy to understand intuitively and requires no special training to read.

Furthermore, if the configuration calculates characteristic values that can express the characteristics of the swing from the trajectory of the subject's center of gravity measured by a load measuring platform and displays the results, parameters that are known to be useful as indicators can be directly used. Since it is presented, anyone can quantitatively understand the degree of suitability of the swing.
The reliability of the diagnosis of the golf swing diagnostic machine is increased.

In this case, the display can be sufficiently utilized even if it is not a two-dimensional display device but a bar display or numerical representation.

In addition, when a subject performs an attempt and the result is favorable, this result is recorded separately, and when it is displayed overlaid with new measurement results from another attempt, it is possible to see the movement of the center of gravity when the subject made his or her best swing. Since the difference between the two is clear, adjustment is easy.

〔Effect of the invention〕

According to the golf swing diagnostic device of the present invention, the movement of the center of gravity during a swing can be measured without the need for an assistant's hands, and the quality of the test subject's swing can be determined from the viewpoint of the appropriateness of the movement of the center of gravity. Further, the judgment given by the diagnostic device has quantitative properties and can be used as an objective index. Furthermore, being able to compare with your own best can be extremely effectively used, for example, for making adjustments before playing.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The golf swing diagnostic device of the present invention will be described in detail below with reference to drawings showing embodiments. Figure 1 shows i of the claimed invention.
FIG. 2 is a plan view showing the arrangement relationship between the load measuring table and the head detector in the embodiment, and FIG. 2 is an elevational view thereof. FIGS. 3 and 4 are drawings showing examples of measurement results obtained by the golf swing diagnostic device. FIG. 5 shows an example of the configuration of a golf swing diagnostic device, and FIG. 6 shows its signal block diagram.

In the present invention, a tee stand (25) is arranged in front of the load measuring table (1). On the load measuring stand (1),
4 load cells (12), (13), (14),
A top plate (1) is provided with four corners supported by (15). The tee stand (25) is equipped with a light receiver (21A) on the front side across the club head path from where the golf ball is set, and a corresponding light emitter (21B) on the other side to detect the passage of the club head. An impact detector (21) that detects the moment of impact, and a light receiver (21) installed in the same manner as above at a position slightly to the right of the pole set position and where the club head always passes at the beginning of the backswing after address. A swing detector (22) consisting of a light transmitter (22A) and a light emitter (22B) for detecting the start of a backswing was provided, and a push button (23) was further provided between the light receivers (21A) and (22A). A head detector (2) is provided.

Note that since it is natural to use a tee for a club with a low number, a tee can be installed at the pole set position.

The test subject holds a club and takes a stance while standing on the load measuring table (1) at approximately the center of the top plate (11). Load cells (12), (13), (1
4) and (15) have been offset by the top plate load in advance by zero adjustment in the load converter (16), so the outputs (Wl), (W2), (W3), (W4)
The total weight (WT) is the weight of the subject on the top plate.

Furthermore, at this time, the output ratio of each load cell differs depending on the relationship between the position where the load is applied and the installation position of the load cell, and by calculating backwards from this, the position where the load is applied, that is, the position where the center of gravity is projected on the horizontal plane I understand. 4 load cells (12), (13), (14
). (15) are placed exactly at the four corners of the square under the top plate (11), the origin is the load cell (12) in the upper left corner of Fig. 1, and the distance between the load cells is set in units of . The horizontal component X and the longitudinal component Y of the center of gravity position, which are expressed as follows, can be determined from X = (W2+W3)/WT Y = (W3+W4)/WT.

Even if the load cell arrangement is not square, the center of gravity position can be calculated by introducing a geometrically determined correction coefficient unique to each arrangement.

When the subject swings and moves on the load measuring table (1),
Accordingly, the output of each load cell changes.

Each output (Wl), (W2), (W3), (W4
) is a load converter (16) equipped with a measurement bridge circuit and an A/D converter, which calculates the load measurement value that compensates for the weight of the top plate (11), converts it digitally, and outputs it. This is the I/O interface. (32), and are sequentially taken into the arithmetic unit (3).

The weight change observed due to the acceleration of the center of gravity as the subject moves up and down and the change in the center of gravity position as a complex with the club head, and the subject's center of gravity position (X, Y) are calculated using a calculation device (
The arithmetic processing means (3l) in 3) allows tracking while calculating according to the above equation. The results are stored in an internal storage means (33) consisting of an IC memory, etc.
If necessary, it is displayed on the display device (4) via the I/O interface (32) and can be viewed by the subject during or after the swing. In addition, external storage devices such as magnetic disks and compact disks (35
) and can be recorded on a magnetic recording medium or optical recording medium.

After confirming that the golf swing diagnostic device is ready for operation using an indicator lamp, display, etc., the test subject sends a start signal to the device to start an attempt. If the start signal is generated by pressing the push button (23) included in the head detector (2) with the club head, the subject can input it by himself without losing his posture just before the address. It's convenient. Of course, it is also possible to use a mechanism that emits a signal when the club head approaches a certain location, a foot pedal, a manual push, a remote switch, etc., or a preparation completion signal generated by the golf swing diagnostic device itself. be.

Next, after addressing the club head to the left side of the swing detector (22), a backswing is started. At this time, the club head blocks the light beam emitted from the light emitter (22B) of the swing detector and interrupts light detection by the light receiver (22A), thereby generating a swing start detection signal. For the emitted and received light beam, the condition is that the club head can block the light beam that enters the light receiver (22A), and a narrow beam with high directionality is preferred, and as the type of beam, infrared rays, which are difficult to exist in the surrounding environment, are selected. is preferable. Other head detectors (2) include placing a magnetic material such as an iron piece in the club head and detecting its passage with a detection coil installed on the tee stand side, or using ultrasonic waves. Various detection principles are available. Note that, contrary to the above, a method is also used in which the club head is detected at the beginning and the head disappears when the swing begins, so that the start of the swing can be detected.

The above detection signal is the I/O interface (
32) serves as a trigger for the arithmetic unit (3), and from this point on, the arithmetic processing means (3l) successively determines the center of gravity position by calculating the above equation. The calculation result of the center of gravity position is stored in the internal storage device (33), and output to the two-dimensional screen display device (4l), recording device (42), or external storage device (35) as necessary to be useful for determination. becomes possible. The control console (34) is used for managing calculation programs, setting measurement parameters, and the like.

FIG. 3 is an example showing a planar projection view of a typical center of gravity locus. The positions of the left foot (LP) and right foot (RF) are indicated by dotted lines.

Analyzing the results of many players' attempts, the trajectory of the center of gravity when making a desirable swing is as follows: When first taking a stance, the center of gravity is approximately halfway between the left and right feet (P
2), when you start your backswing, it moves almost linearly toward your right foot, reaching the inside of your right foot (RF), which is the far right end, and starts your downswing from there. During the downswing, the center of gravity shifts slightly toward the toes, so the trajectory of the center of gravity moves to the left while drawing a gentle arc forward. This arc expands the most at the front position of the body, and as the club head approaches the tee position, it returns to the front again, and at the far left end of the arc, it is around the middle of the left foot (LP), and the left and right feet. The line (P1) is reached. It is preferable to make an impact here. In the follow swing after impact, the center of gravity trajectory ends in a natural small circle behind the inside of the left foot (LP).

The above is a typical center of gravity trajectory, and even if the club and flying distance are different, the basic pattern will not change much. However, the optimal trajectory, for example, the trajectory that maximizes head speed, differs somewhat depending on the person and conditions. Some people prefer the trajectory during the downswing to be shaped like a triangle with a wide base and an apex instead of a gentle arc. Of course, the optimal pattern will change depending on the number of clubs you swing and the distance you are aiming for.

Although the optimal pattern varies depending on the conditions of each person, the trajectory of the center of gravity in a person's own best swing under certain conditions is reproducible, so the trajectory of the center of gravity measured by the device of the present invention is the best pattern. It's a good indicator to check if your swing is going well. Therefore, when measuring and displaying a swing, if the trajectory of the player's best swing is displayed overlaid, it will be useful not only for improving the player's technique, but also for adjusting the player's condition just before playing. become.

Figure 4 shows the X-direction (X) and Y-direction components (Y) of the change in the center of gravity position, as well as the change in load (W), along with a vertical line (P1) representing the time of impact, on the time axis. It is something. In the embodiment, it is viewed through a display device (4).

The backswing progresses relatively slowly until the center of gravity moves in the lateral direction of the body, that is, reaches its maximum value in the X direction.

You can think of the downswing as up to impact,
The distance is defined as a point separated by a vertical line (Pi) drawn by the signal of the impact detector (2l). During this time, the moving speed of the center of gravity gradually increases from the start of the downswing, so the amount of change in the center of gravity in the X direction becomes large, and it is good to reach the impact at approximately the maximum value on the left side. In addition, in the Y direction, as the weight is slightly applied to the tip of the toe, the center of gravity moves forward, reaching the largest value near the center of the X direction, and reaching its maximum value when it crosses the initial value near impact This results in a good swing.

In the follow swing, after the Y value once reaches the maximum backward value, it swings backwards from the initial Y value, and the X value swings back to the right side, in the positive direction. The time it takes to first reach the extreme value and the distance on the X coordinate from the left extreme value are important as they are related to the quality of the swing form.

Additionally, the load decreases in the latter half of the backswing as the club head is lifted, begins to increase in the downswing, and rapidly increases as the head speed increases. Since the load at the moment of impact influences the head speed, it is preferable that the load reaches its maximum value at the moment of impact.

From the above, ■center of gravity trajectory, ■distance and time of center of gravity movement during backswing, center of gravity movement distance and time during downswing, center of gravity movement width and time of follow swing, ■horizontal length of center of gravity trajectory, and vertical width , that is, the difference between the Y value at the address start point (P2) and the Y value when the center of gravity is most forward during the downswing, ■center of gravity and load at impact,
■It was found that the characteristics of a swing can be expressed well by using indicators such as the change in load during the swing.

For example, when the center of gravity moves close to the outside of the right foot (RF) and the distance traveled by the center of gravity during the backswing is not long, a sway occurs, and the trajectory of the center of gravity converges in the middle of both feet and does not spread sufficiently to the left and right. When the lateral length of the center of gravity trajectory is small, this indicates that the player enters the downswing before shifting his weight sufficiently to the right during the backswing, and that the weight remains on the right foot even after impact.

In addition, the lower surface of the top plate (11) is formed with a recess in the part that corresponds to the load cell so that the contact position of the pressure receiving member of the load cell does not change even if the top plate is tilted. (.12), (13),
If the postures of (14) and (15) are changed in conjunction and the pressure receiving direction is maintained vertically, the load measuring table can be tilted appropriately, making it possible to swing on the slope. It is useful for practicing troubleshooting during play.

In the above description, it is assumed that the orientation of the device and body is limited to left and right, but it goes without saying that the device can be used as is for left-handed subjects by arranging the head detector in the opposite direction.

Furthermore, although numbers referring to drawings are added in the description of the claims, these are added for the purpose of aiding understanding, and do not limit the technical idea of the claimed invention. Needless to say.

[Brief explanation of drawings]

The drawings show an embodiment of the golf swing diagnostic device according to the present invention, and FIG. 1 is a plan view showing the arrangement relationship between a load measuring table and a head detector in one embodiment of the present invention, and FIG. 2 is an elevational view thereof. , Fig. 3 and Fig. 4 are respectively plane projection diagrams of the trajectory of the subject's center of gravity and examples recording changes over time. Fig. 5 is a drawing explaining the equipment configuration in the embodiment of the present invention, and Fig. 6 is its block diagram. This is a diagram. (1)... Load measuring table, (2)... Head detector, (3)... Arithmetic device, (4)...
... Display device, (12) to (15) ... Load cell, (21), (22) ... Head detection light receiver, (41) ... Display, (42)... Plotter.

Claims (1)

[Claims] 1. A load consisting of a top plate (11) on which a subject is placed and three or more load cells (12), (13), (14), and (15) that support the top plate installed on the lower side of its periphery. A measuring table (1), a detector (21) for detecting the passage of the club head at the position where the golf ball is set and the address position of the club head, (
22) and a head detector (2) provided with a head detector (2), the load measuring table (1)
load cells (12), (13), (14), (15)
A computing device (3) that calculates the center of gravity position of the load on the top plate (11) from the load measurement output of and a display device (4) that displays the center of gravity position (I) at the time of impact. 2. In the golf swing diagnostic machine equipped with the load measuring table (1), the head detector (2), and the calculation device (3), a display device (4) that displays the subject's total load and center of gravity position at the time of impact. ) is a golf swing diagnostic device. 3. In a golf swing diagnostic machine equipped with the load measuring table (1), the head detector (2), and the calculation device (3), the changes in the measured load before and after the impact are continuously measured along with a marker indicating the impact point. A golf swing diagnostic device equipped with a display device (4) that displays information. 4. Claim 3, wherein the display device (4) continuously displays changes in the total load and the components of the center of gravity in both plane coordinate axes directions.
The golf swing diagnostic machine described. 5. Storage device for recording measurement results from test subjects' attempts (
33), (35), and when displaying a new measurement result on the display device (4), the storage device (33), (3
5. The golf swing diagnostic device according to claim 1, wherein the golf swing diagnostic device is configured to display the records retrieved from 5) superimposed on the measurement results. 6. In the golf swing diagnostic device including the load measuring table (1) and the head detector (2), load cells (12), (13), (14), (
2. The golf swing diagnostic device according to claim 1, further comprising: an arithmetic device (3) that calculates a characteristic value of the subject's center of gravity trajectory from the load measurement output of step (15); and a display device (4) that displays the result. 7. The characteristic values of the center of gravity trajectory calculated and displayed are the lateral distance and time of the center of gravity movement during the backswing, the lateral distance and time of the center of gravity movement during the downswing, and the vertical movement width;
Claim 6 including any one of the vertical distance of the center of gravity movement during the follow swing, the center of gravity position at impact, and the load.
The golf swing diagnostic machine described.