JPH07227453A - Motion measuring instrument for golf club head - Google Patents

Abstract

PURPOSE:To exactly obtain the motion data of a head at the time of ball hitting CONSTITUTION:Three marks 14a-14c are formed on a face plane 12, the marks 14a-14c are extracted from the multiplx images picked up from the motion of the club head by two image pickup devices at the time of ball hitting, and thier three-dimensional coordinates are calculated. Thus, since the motion of marks 14a-14c, namely, the attitude of the face plane 12 and the change of speed can be three-dimensionally (stereoscopically) grasped, the attitude of the face plane 12 or the like at the time of ball hitting can exactly be grasped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a golf club head motion measuring apparatus for obtaining motion data of a golf club head when hitting a ball.

[0002]

2. Description of the Related Art Conventionally, various devices for diagnosing golf swing have been proposed. For example, it is known that a plurality of cameras are used to image a golfer's form (for example, Japanese Examined Patent Publication No. 5-37661). However, the direction of the hit ball is not uniquely determined by the form, but is determined by the direction of the face surface at the time of hitting the ball, the velocity vector of the head, etc. The loft at the time of hitting may change, and good results cannot be obtained. Therefore, the above-mentioned prior art cannot provide adequately appropriate advice.

Further, there is known one in which only one mark is attached to the tip of a club and multiple images are taken by a plurality of cameras (Japanese Patent Publication No. 5-55157). However, in this prior art, only the approach data of the club is grasped, and since each camera captures only a two-dimensional image, the direction and velocity vector of the face surface at the time of hitting is grasped. Can not do it. Therefore, it is impossible to give appropriate advice, particularly in selectively providing a golf club according to a club specification such as a loft.

The present invention has been made in view of the above conventional problems, and an object of the present invention is to provide a movement measuring device for a golf club head which can accurately obtain movement data of the head when hitting a ball.

[0005]

In order to achieve the above object, the present invention provides first and second image pickups in which multiple marks of marks provided at at least three points on a face surface of a golf club head are picked up from different points. Apparatus, mark extracting means for extracting the mark from the images captured by the first and second image capturing devices, and three-dimensional calculation of the three-dimensional coordinate of the mark from the two-dimensional coordinate of the mark obtained by the mark extracting means And coordinate calculation means.

[0006]

Next, the principle of the present invention will be described. In order to improve the player's swing and select the optimum club for each player, detailed data such as the velocity vector V and the face surface vector F in FIGS. 1B and 1C at the time of hitting the ball are required. . Here, since the velocity vector V and the face surface vector F are three-dimensional, they cannot be obtained even by two-dimensionally imaging with one imaging device. Therefore, in the present invention, a change in the posture of the face 12 is picked up by two image pickup devices, and the two images are combined to three-dimensionally grasp the change in the face 12 so that it can be grasped. .

On the other hand, even if it is attempted to grasp the entire face surface 12, the image data becomes enormous, which makes it difficult to process the data. Therefore, in the present invention, the posture of the face surface 12 is specified by providing the three marks 14a to 14c on the face surface 12. That is,
By combining two two-dimensional data relating to the marks 14a to 14c by the three-dimensional coordinate calculating means, the mark 14a
The three-dimensional coordinates of 14c are obtained, and based on these three-dimensional coordinates, it is possible to obtain the change in the attitude or velocity vector of the three-dimensional face 12.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1A, marks 14a to 14c are provided at three points on the face surface 12 of the golf club head 11 for measurement. These marks 14a-
14c is a circular light reflection plate with a diameter of about 4 mm,
The head center 13 is attached at a position forming a triangle. If necessary, face 1
The marks 14a to 14c may be attached after the whole 2 is colored black.

FIGS. 1B and 1C show the arrangement of the first and second image pickup devices 2 and 3. The first imaging device 2 is
It is located diagonally above the front side. On the other hand, the second image pickup device 3 is arranged at a diagonally lateral position in the front, as shown in FIG. In addition,
Both of the image pickup devices 2 and 3 are actually arranged at positions farther from the golf ball 4 than in this figure.

In FIG. 2, both the image pickup devices 2 and 3 simultaneously pick up images in synchronization with a timing signal output from the image processing device 5, and the first and second image pickup devices 2 and 3 are respectively attached to the image pickup devices 2 and 3. The strobes 21 and 31 are simultaneously activated by the timing signal. As a result, multiple image pickups are simultaneously performed by the image pickup devices 2 and 3 while causing the strobes 21 and 31 to emit light 10 times at predetermined image pickup timings.

The two-dimensional image data picked up by the image pickup devices 2 and 3 are taken into the image processing device 5 and subjected to image processing as described below. First, each image data of both imaging devices 2 and 3 is stored in a frame memory (not shown), and then input images are switched by the input image switching unit 50 to be sequentially input to the mark extracting unit 51. The mark extracting means 51 selects, for example, image data having a large amount of light from each image data, that is, two-dimensional coordinates of only the shining point, and
The two-dimensional coordinates of the marks 14a to 14c shown in (a) are extracted. The image data group of the extracted two-dimensional coordinates includes, in addition to the data of the marks 14a to 14c, noise due to a shining portion on the face surface 12 or edges.

The image data of each two-dimensional coordinate from the mark extracting means 51 of FIG. 2 is output to the three-dimensional coordinate calculating means 53, and the three-dimensional coordinate calculating means 53 causes the three-dimensional coordinate as shown in FIG. 3, for example. Converted to coordinate image data. It should be noted that this conversion is performed by the DLT method in which a combination of two-dimensional coordinates is brute force. That is, the first of FIG.
And two-dimensional data points appropriately selected from the image data group of the marks extracted from the first imaging device 2 by incorporating the camera coefficients stored in advance in the second camera coefficient storage units 52A and 52B, and the second imaging The three-dimensional points that can be combined from the two-dimensional data points appropriately selected from the image data group extracted from the device 3 are constructed by the DLT method, and then the error evaluation is performed. Used as the coordinates of the original point.

Further, the three-dimensional coordinate calculating means 53 has three-dimensional coordinates Ma, Mb of the marks 14a-14c shown in FIG.
, Mc are extracted to remove the noise N. That is, three points are selected from all the extracted points Ma, Mb, Mc, N, and G to form a triangle, and the lengths of the three sides of one triangle are obtained. If the three points are marks 14a to 14c extracted at arbitrary image capturing timings, the lengths of the three sides are always constant regardless of changes in the image capturing timings. It is determined whether or not the lengths of the three sides when tied to each other have predetermined values, and by selecting those having the predetermined values, only the three-dimensional coordinates Ma, Mb, Mc of the marks 14a to 14c are selected. To extract.

Here, the three-dimensional coordinates Ma, Mb, and
There may be a ghost G that forms a predetermined triangle when combined with two points even though it is not Mc.
The operator determines the ghost G while looking at the image on the display 7 (FIG. 2). That is, since the three-dimensional coordinates Ma, Mb, Mc forming the triangle are displaced diagonally downward A in FIG. 3 according to the movement of the head 11 (FIG. 1),
The coordinate G can be recognized as a ghost, and therefore the operator operates the input unit 6 (FIG. 2) to remove the ghost G. As a result, only the three-dimensional coordinates Ma, Mb, Mc of the mark are extracted, and the direction and position of the face surface 12 at each imaging timing are specified.

The three-dimensional coordinate calculating means 53 in FIG. 2 outputs the three-dimensional coordinates Ma, Mb, Mc of the mark to the three-dimensional data calculating means 54. This three-dimensional data calculation means 54
Upon receiving the data of the three-dimensional coordinates Ma, Mb, Mc of the mark, the velocity vector calculating means 54a and the face surface vector calculating means 54b respectively calculate the three-dimensional data of the velocity vector V and the face surface vector F of FIG. .
The velocity vector V is a vector composed of a velocity and a direction in which the head center 13 moves at the time of hitting a ball.
The face surface vector F is the three marks 14a-14
It is a vector in the normal direction of a plane including c, that is, a vector in the normal direction of the face surface 12.

Here, since the golf ball 4 of FIGS. 1B and 1C is an obstacle, in both image pickup devices 2 and 3,
It is not possible to capture an image when hitting a ball. Therefore, the three-dimensional data calculating means 54 in FIG. 2 estimates and calculates the velocity vector V and the face surface vector F at the time of hitting from the velocity vector V and the face surface vector F before the hitting. For example, if the velocity changes as shown by the solid line as shown in FIG. 4, then it is estimated that the velocity changes as shown by the chain double-dashed line, and the velocity v at the time of hitting the ball is calculated.

The three-dimensional data calculation means 54 shown in FIG.
The data of the obtained velocity vector V and face surface vector F is output to the evaluation data calculation means 56. The evaluation data calculation means 56 calculates the face surface direction θf and the actual loft θ in FIG. 1 from the velocity vector V and the face surface vector F.
r, means 56a to 56d (FIG. 2) for calculating the face approach angle θe and the driving angle θi. Here, the face surface direction θf in FIG. 1C is an angle formed between the horizontal projection vector F _XY of the face surface vector F and the target direction P. The face approach angle θe is the velocity vector V
Of the horizontal projection vector V _XY and the direction P to be aimed at. Further, the actual loft θr in FIG. 1B is an angle formed by the face surface 12 and the normal line G1 of the ground G when the ball is hit.
Further, the driving angle θi means an angle formed by the velocity vector V and the ground G (horizontal plane H).

The evaluation data calculating means 56 in FIG. 2 outputs these angles θf, θr, θe and θi to the correction parameter calculating means 57. Correction parameter calculation means 5
Reference numeral 7 compares the model data θf, θr, θe, and θi previously stored in the model type storage unit 58 with the data θf, θr, θe, and θi of the person to be diagnosed, and the difference between them is determined by the printer 8 Output to. As a result, the person to be diagnosed has a face surface direction θ during his / her swing.
It is possible to know how to correct f, the actual loft θr, the face approach angle θe, and the driving angle θi.

Here, it is difficult for a person to perceive with the three-dimensional data, that is, the velocity vector V and the face surface vector F as they are. On the other hand, in this embodiment,
The three-dimensional data of the velocity vector V and the face surface vector F is converted into two-dimensional data of the face surface direction θf and the like as viewed from the horizontal and from above. Therefore, the person to be diagnosed can easily understand his or her own defects.

On the other hand, the three-dimensional coordinate calculating means 53 shown in FIG.
The data group of the three-dimensional coordinates Ma, Mb, Mc of is output to the display image creating means 55. This display image creating means 55
Creates an image (side surface image and plane image) in which these coordinates are projected on the ZX plane and the XY plane of FIG. 3 from the data of the three-dimensional coordinates Ma, Mb, Mc, and outputs the image to the display 7. . Therefore, the display 7 shows how the marks 14a to 14c (FIG. 1) have moved when viewed from above.
It shows how a to 14c (FIG. 1) moved when viewed from the side.

Here, even if the changes in the three-dimensional coordinates Ma to Mc are displayed on the display 7 with the three-dimensional coordinates as they are, the display 7 can be expressed only in two dimensions. It is difficult to understand changes in the face posture. On the other hand, as in the present embodiment, by converting the three-dimensional coordinates Ma to Mc into two-dimensional coordinates, it is possible to grasp the change in the posture of the face surface 12 as seen from above and the side surfaces, so that the diagnosis is performed. The person can easily know his or her fault.

By the way, in the present embodiment, the three-dimensional data calculating means 54 estimates the data at the time of hitting the ball from a plurality of data before hitting the ball, as shown in FIG. .

In this embodiment, two image pickup devices 2,
Although 3 is installed in different places, in the present invention, 3 or more image pickup devices may be installed in different places, thereby increasing the measurement range and improving the measurement accuracy.

[0024]

As described above, according to the present invention,
Marks are provided at at least three places on the face surface, and the marks are taken in multiple images from two different places. Therefore, the three-dimensional coordinates of the mark can be known from the two two-dimensional images. You can know three-dimensional changes such as postures accurately. Therefore, it becomes possible to give appropriate advice to the person to be diagnosed.

[Brief description of drawings]

FIG. 1 is a front view, a side view, and a plan view of a club head showing the principle of the present invention.

FIG. 2 is a schematic configuration diagram of a measuring device showing an embodiment of the present invention.

FIG. 3 is a chart showing a mark extraction method.

FIG. 4 is a chart showing a method of estimating a velocity when hitting a ball.

[Explanation of symbols]

 2: 1st imaging device 3: 2nd imaging device 12: Face surface 14a-14c: Mark 51: Mark extraction means 53: Three-dimensional coordinate calculation means Ma-Mc: Three-dimensional coordinate of a mark

Claims (1)

[Claims] 1. A first and second imaging device for multiplex-imaging marks provided at least at three points on a face surface of a golf club head from different points, and images taken by the first and second imaging devices. A movement measuring device for a golf club head, comprising mark extracting means for extracting the mark, and three-dimensional coordinate calculating means for calculating the three-dimensional coordinate of the mark from the two-dimensional coordinate of the mark obtained by the mark extracting means.