JP6029369B2 - Swing simulation method - Google Patents

Description

  The present invention relates to a swing simulation method.

  In a swing using a golfer club, the head speed and blow angle significantly reflect the swing characteristics of each golfer. The swing characteristic amount such as the head speed and the blow angle is mainly caused by an input from an object that is a main subject of the swing such as a golfer. It is considered to be very important to develop a golf club that allows golfers to realize ideal swing features.

  Therefore, in designing and developing a golf club, it is very useful to simulate the swing and analyze the feature amount. In addition, information obtained by such an analysis can be a very important index when a golfer selects an optimal golf club capable of realizing an ideal swing.

  As a method of analyzing the behavior of a golf club during a swing by a golfer, conventionally, a swing is measured, a golfer's joint angle is derived, a torque acting on the joint is derived, and the golfer's arm model and golf club model There has been proposed a method for performing simulation by setting (see, for example, Patent Document 1). According to such a method, simulation calculation can be stabilized.

JP 2010-11926 A

  In the golf club behavior analysis method described in Patent Document 1, the swing arm model is caused to follow the joint angle and torque obtained by measurement, and the golf club is swung during simulation. However, when the swinging golf club is changed, the joint angle and torque that the golfer can actually perform differ depending on the muscle strength of the golfer and the like. On the other hand, in the golf club behavior analysis method described in Patent Document 1, the swing arm model is forced to follow the measured joint angle and torque even when the weight of the golf club is changed during simulation. Therefore, there is a possibility that the simulation result is far from the actual swing.

  Accordingly, an object of the present invention made in view of such circumstances is to provide a swing simulation method capable of obtaining a simulation result close to an actual swing when simulating a swing using a golf club.

A swing simulation method according to the present invention for achieving the above object is a swing simulation method using a golf club by a golfer,
A measurement step of three-dimensionally measuring the swing to obtain the golfer's body behavior and the golf club behavior;
A parameter calculating step of calculating a parameter including a joint torque of the golfer using the golfer body behavior data and the golf club behavior data obtained by the measuring step ;
Setting the golfer's musculoskeletal model using body parameters including the golfer's muscle strength level;
The golf player's musculoskeletal model is input with the parameters calculated in the parameter calculating step, and the golf club model of the golf club is swung. and a simulation step of Ru to reflect on,
A feature amount calculating step for calculating a swing feature amount based on a simulation result of the simulation step;
It is characterized by including.

  According to the swing simulation system of the present invention, a simulation result close to an actual swing can be obtained.

In the swing simulation method according to the present invention, in the measurement step,
The body behavior of the golfer is acquired as three-dimensional position time-series data of the golfer's shoulder, elbow, wrist, and hand, and the behavior of the golf club is acquired as three-dimensional position time-series data of the grip portion of the golf club. It is preferable to do.

  According to this configuration, the simulation accuracy can be further improved.

In the swing simulation method according to the present invention, in the parameter calculation step,
It is preferable that the parameter including joint torque is calculated based on time series data of angles of joints including shoulder, elbow, and wrist of the golfer.

Furthermore, in the swing simulation method according to the present invention, the body parameters further include height, weight, length between joints, moment of inertia constant, circumference of each part of the body, joint position coordinates, and degrees of freedom of joints. It is preferable to include at least one selected.
According to these configurations, the simulation accuracy can be further improved.

  According to the present invention, a simulation result close to an actual swing can be obtained.

5 is a flowchart for explaining a swing simulation method according to an embodiment of the present invention. It is a figure for demonstrating an example of the acquisition method of the golfer's body behavior in the simulation method of the swing which concerns on one Embodiment of this invention. It is a figure which shows an example of the golf club used for the simulation method which concerns on one Embodiment of this invention. It is a figure for demonstrating an example of the acquisition method of the golfer's body behavior in the swing simulation method which concerns on one Embodiment of this invention, and the behavior of a golf club.

  Hereinafter, a swing simulation method according to an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a flowchart for explaining a swing simulation method according to an embodiment of the present invention. In the simulation method of the present embodiment, first, the golf club is swung by the golfer, the swing is three-dimensionally measured, and the measurement step of acquiring the body behavior of the golfer 2 and the behavior of the golf club is performed (step S01).

  In step S01, the behavior of the golfer's arm is acquired as the body behavior of the golfer, and the behavior of the grip portion of the golf club is acquired as the behavior of the golf club. As shown in FIGS. 2 (a) and 2 (b), in step S01, first, a plurality of markers 3 (indicated by white circles in the figure) for reflecting light to the golfer (subject) 2 are fixed. The marker 3 is fixed to the shoulder, elbow, wrist, and hand of the golfer 2. Based on the behavior data of the grip part, the wrist joint angle (bending, crooking, etc.) and torque are calculated. The golfer 2 of this embodiment is right-handed. Moreover, in this embodiment, the movement locus | trajectory of the arm (left arm) on the opposite side to the dominant arm of the golfer 2 is acquired. For this reason, in order to improve the measurement accuracy, more markers 3 are fixed to the left arm of the golfer 2. The reason for the left arm is that the golf swing trajectory has a large contribution from the arm opposite to the dominant arm, and second, the removal of the right arm prevents the swing arm model described later from becoming a complex closed loop. This is to help. However, it goes without saying that the trajectory of the right arm or both arms may be obtained.

  Further, as shown in FIG. 3, a plurality of markers 3 are also fixed to the golf club 4. The behavior of the grip portion of the golf club is acquired by the marker 3 fixed to the golf club 4. The marker 3 is fixed to the upper portion of the grip portion 4c, the shaft portion 4a immediately below the grip portion 4c, and a position spaced from the shaft portion 4a via an attachment member j or the like.

  Next, as shown in FIG. 4, after mounting the marker 3, the golf club 2 is caused to swing the golf club 4. The swing is an address in a stationary state (Fig. A), a top for lifting the golf club 4 from the address to the top (Fig. B), swinging the golf club down from the top, impact, follow-through, A series of operations up to the finish (FIGS. C to e) are included.

  In addition, a series of swing operations are three-dimensionally photographed by an optical motion capture system. In the three-dimensional shooting, for example, the swing of the golfer 2 is shot from different directions by a plurality of CCD cameras having an infrared strobe and synchronized. In this embodiment, the sampling frequency is 250 Hz, and the resolution is 1280 × 1024 pixels.

  The captured image data of the swing is taken into a computer, and the position of each marker 3, that is, the three-dimensional position time-series data of each marker 3 is sequentially acquired. Then, from the three-dimensional position data of the marker 3, the three-dimensional motion trajectory of the swing of the left arm of the golfer 2 and the behavior of the golf club 4 are obtained. That is, the movement trajectory of the upper arm part using the shoulder joint of the left arm, the forearm part connected by the upper arm part and the elbow joint, and the wrist part connected by the forearm part and the wrist joint, and the movement trajectory of the grip part of the golf club 4 are as follows. It is derived from the three-dimensional position data of the marker 3.

  Next, a parameter calculation step for calculating a parameter including the joint torque of the golfer 2 from the motion trajectory acquired in the above step is performed (step S02). The parameter is preferably calculated based on time-series data of angles of joints including the shoulder, elbow, and wrist of the golfer 2.

  In the present embodiment, the position of each joint of the golfer 2 can be estimated using motion capture software. The software can calculate the position at each joint and each angle using a fixed simulated frame with a constant vector length between the joints of the shoulder, elbow and wrist. Then, the torque acting on the shoulder, elbow, and wrist joints of the golfer 2 that moves at the calculated joint angle is calculated. In the present specification, the term “torque” is used synonymously with “moment”.

  Here, in this step, when calculating the torque, the torque acting on the shoulder, elbow and wrist joints of the golfer 2 is calculated based on the inverse dynamics calculation. Inverse dynamics calculation is a method of calculating a force that becomes a driving force by inputting motion data (here, time-series data of angles of each joint) to a motion equation of the body. More specifically, by giving the angle (angular velocity or angular acceleration) of each joint of the left arm of the golfer 2, the torque (joint reaction force) acting on each joint can be calculated in time series. Such inverse dynamics calculation can be easily performed by executing general-purpose software (for example, general-purpose mechanism analysis software “MYDYMO” manufactured by TNO) with a computer.

  Next, the simulation step of swinging the golf club model of the golf club is performed by inputting the parameter calculated in step S03 to the musculoskeletal model of the golfer 2 (step S03). Based on the simulation in this step, the muscle tension and joint torque of the golfer 2 can be analyzed, and further the behavior of the golf club model can be analyzed.

  The musculoskeletal model of the golfer 2 is, for example, a musculoskeletal model described in JP 2010-29340 A. According to the musculoskeletal model, the joint torque calculated from the motion data of the golfer 2 is mapped to the muscle tension. be able to.

  Here, prior to the implementation of this step, body parameters such as height, weight, length between joints, moment of inertia constant, muscle strength level of each part of body, perimeter of each part of body, joint position coordinates, degree of freedom of joint, etc. Is used to set a musculoskeletal model suitable for the golfer 2. By using the appropriate musculoskeletal model set in this way for the simulation of the swing, even when the golf club model used for the simulation is changed, the muscular strength and joint torque that the golfer 2 can actually exert in the swing are simulated. The simulation result can be brought close to the actual simulation.

  In addition, the golf club model used in this step is a golf club model in which other than the head portion 4b is set as an elastic body, for example. By changing the input parameters of the golf club model (for example, shaft characteristics including bending rigidity and torsional rigidity, and head characteristics including the center of gravity, mass, and volume), various golf clubs 4 can be obtained. Information regarding the bending and twisting of the golf club 4 in the swing of the golfer 2 when used can be obtained.

  Then, based on the simulation result in step S03, a feature amount calculation step for calculating a swing feature amount such as a head speed and a blow angle is performed (step S04). Here, by using the golf club model in which the part other than the head part 4b is set as an elastic body in step S03, it is possible to detect a feature amount such as a head speed and a blow angle in which the influence of the bending and twisting of the shaft is reflected. Become. These feature amounts are very effective for the golfer 2 to select a suitable golf club and to develop a golf club.

  As described above, according to the swing simulation method according to the present embodiment, when the weight of the golf club is changed in the simulation, it is possible to reflect individual differences such as the muscular strength of the golfer, and to improve the simulation accuracy. Can do.

  It will be apparent to those skilled in the art that many changes and substitutions can be made within the spirit and scope of the invention as described above. Therefore, the present invention should not be construed as being limited by the above-described embodiments, and various modifications and changes can be made without departing from the scope of the claims.

2: Golfer 3: Marker 4: Golf club 4a: Shaft 4b: Head 4c: Grip j: Mounting member

Claims (4)

A swing simulation method using a golf club by a golfer,
A measurement step of three-dimensionally measuring the swing to obtain the golfer's body behavior and the golf club behavior;
A parameter calculating step of calculating a parameter including a joint torque of the golfer using the golfer body behavior data and the golf club behavior data obtained by the measuring step;
Setting the golfer's musculoskeletal model using body parameters including the golfer's muscle strength level;
The golf player's musculoskeletal model is input with the parameters calculated in the parameter calculating step, and the golf club model of the golf club is swung. and a simulation step of Ru to reflect on,
A feature amount calculating step for calculating a swing feature amount based on a simulation result of the simulation step;
A method of simulating a swing, comprising: In the measuring step,
The body behavior of the golfer is acquired as three-dimensional position time-series data of the golfer's shoulder, elbow, wrist, and hand, and the behavior of the golf club is acquired as three-dimensional position time-series data of the grip portion of the golf club. The swing simulation method according to claim 1, wherein: In the parameter calculation step,
The swing simulation method according to claim 2, wherein the parameter including joint torque is calculated based on time series data of angles of joints including a shoulder, an elbow, and a wrist of the golfer.   The body parameters further include at least one selected from height, weight, length between joints, moment of inertia constant, circumference of each part of the body, joint position coordinates, and degree of freedom of joints. The swing simulation method according to claim 1.

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