JP2015002911A - Motion analysis device and motion analysis program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motion analysis device and a motion analysis program capable of easily presenting rotation of a shaft part of a sports implement as one index in a motion analysis.SOLUTION: A first detection unit 31 detects a first state of a shaft part of a sports implement by using output of an inertial sensor 12. The first state corresponds, for example, to a stationary state. A second detection unit 32 detects a second state of the shaft part of the sports implement by using the output of the inertial sensor 12. The second state corresponds, for example, to an impact. The second detection unit 32 detects a relative rotation angle of the shaft part which has been changed around an axis of the shaft part from the first state.

Description

  The present invention relates to a motion analysis device, a motion analysis program, and the like.

  The motion analysis device is used for motion analysis such as swing motion. The exercise equipment is swung during the swing. The grip of the exercise equipment is held by hand when shaking. When the exercise tool is shaken, the posture of the exercise tool changes according to the time axis. An inertial sensor is attached to the exercise equipment. The swing motion is visually reproduced based on the output of the inertial sensor. As a specific example of such a motion analysis device, for example, a golf swing analysis device is disclosed as disclosed in Patent Document 1.

JP 2008-73210 A

  For example, a golf swing starts with an address, takes back, halfway back, top to down swing, impact, follow-through, and finish. At the start of the golf swing, the subject determines in advance the posture of the golf club at the time of impact based on the address. As a result, the face direction of the club head is set. If the face orientation at the time of address is reliably reproduced at the time of impact, the hit ball will fly as expected. However, in reality, it is difficult to establish the same face orientation as that at the time of impact as expected. Therefore, it has become necessary to indicate to the subject the comparison of the relative rotation angle of the shaft portion of the golf club and the orientation of the face angle of the club head at the time of addressing and impact. Using an optical motion capture device with multiple cameras installed, it is possible to capture the face angle of the ball hitting surface of the golf club at the time of addressing and impact, and specify the orientation of the face angle from the image. It was lacking in convenience because it was large and difficult to install outdoors.

  According to at least one aspect of the present invention, it is possible to provide a motion analysis apparatus and a motion analysis program capable of easily presenting the rotation of the shaft portion of the exercise tool as one index in motion analysis.

  (1) According to one aspect of the present invention, a first detection unit that detects a first state of the shaft portion of the exercise tool using an output of the inertia sensor, and a shaft of the exercise tool that uses the output of the inertia sensor And a second detector that detects a relative rotation angle of the shaft portion that has changed around the axis of the shaft portion from the first state.

  Exercise equipment is held by hand. The exercise equipment is swung during the swing. When shaken, the posture of the exercise device changes along the time axis. At the start of the swing, the subject determines in advance the posture of the exercise tool at the time of impact. From here, the swing operation including the impact is performed again. In one aspect of the present invention, for example, the relative rotation angle around the axis of the shaft portion of the exercise tool at a certain position during the addressing and during the swing, the relative rotation angle between the first state and the second state during the swing, etc. Detected. If the relative rotation angle is visually displayed on the screen of the display device based on the image data, the rotation around the shaft portion of the exercise tool can be presented to the subject. It is known that the rotation of the shaft portion of the exercise tool affects the direction of the hit ball after impact. The subject can improve the swing form in response to the presented rotation of the shaft portion. Compared to optical motion capture using multiple cameras, the rotation angle around the shaft of the exercise tool can be measured simply by attaching the inertial sensor to the exercise tool. There are merits such that it is possible to use, and it can be used outdoors, so it can be used anywhere.

  (2) The first state may be a stationary state before starting the swing operation, and the second state may be an operation state after starting the swing operation. During the swing operation, the relative rotation angle between the address and a certain position during the swing is detected around the axis of the shaft portion of the exercise tool. If the relative rotation angle is visually displayed on the screen of the display device based on the image data, the rotation around the shaft portion of the exercise tool can be presented to the subject. It is known that the rotation of the shaft portion of the exercise tool affects the direction of the hit ball after impact. The subject can improve the swing form in response to the presented rotation of the shaft portion.

  (3) The first detection unit specifies the direction of the hitting surface of the exercise tool in the first state, and the second detection unit specifies the direction of the hitting surface of the exercise tool in the second state. be able to. The direction of the striking surface of the exercise tool may be specified based on the amount of change in the rotation angle around the shaft portion. For example, in the case of a golf club, the orientation of the face angle of the club head may be specified. The subject can improve the swing form according to the orientation of the face angle of the club head to be presented.

  (4) The motion analysis apparatus may include a first display unit that displays the relative rotation angle. For example, by displaying the relative rotation angle around the axis of the shaft portion of the exercise tool at the time of addressing and impact, it can be used as a tool that encourages the subject to improve.

  (5) The first display unit can display a change in the relative rotation angle according to a time during the swing motion of the exercise tool. According to such a display means, since the change in the relative rotation angle is visually presented according to the time during the swing operation, the subject can intuitively recognize the degree of change and the speed of change. In accordance with such perception, the subject can make improvements to the swing form.

  (6) The first display unit can also display comparison data of the change in the relative rotation angle. According to such display means, for example, in the case of a golf swing, it is possible to compare and display a subject's swing motion and a professional swing motion or a swing motion of another subject having the same skill as himself. Depending on the comparison, the subject can make improvements to the swing form.

  (7) The inertial sensor includes a detection axis parallel to the axis of the shaft portion of the exercise tool, and can detect an angular velocity generated around the axis. For example, using an angular velocity sensor as the inertial sensor and aligning the detection axis of the angular velocity sensor with the axial direction of the shaft part of the exercise equipment, the relative rotation angle around the axis of the exercise equipment shaft part is detected using the output of the angular velocity sensor it can.

  (8) The motion analysis apparatus may include an event detection unit that identifies an event during a swing operation using an output of the inertial sensor, and a calculation unit that associates the relative rotation angle with the event. Several events (events) occur during a swing operation such as impact, back swing, top, and down swing. If the relative rotation angle is specified for each of these events, the subject can easily improve the swing form.

  (9) The motion analysis apparatus may include a second display unit that displays the relative rotation angle together with the notation of the event. According to such a display means, since the relative rotation angle is visually presented for each swing event, the subject can intuitively recognize the relationship between the relative rotation angle and the event. Based on such recognition, the subject can make improvements to the swing form.

  (10) The second display unit can display the relative rotation angle comparison data for each event. According to such display means, it is possible to compare and display a subject's swing motion and a professional swing motion or a swing motion having skills equivalent to those of the subject. Thus, the subject's relative rotation angle can be compared with the professional relative rotation angle for each event. Depending on the comparison, the subject can make improvements to the swing form.

  (11) In another aspect of the present invention, a procedure for detecting a first state of the shaft portion of the exercise tool using the output of the inertia sensor, and an output of the shaft portion of the exercise tool using the output of the inertia sensor. The present invention relates to a motion analysis program for causing a computer to execute a procedure for detecting a second state and a procedure for detecting a relative rotation angle of the first state and the second state of the shaft portion that change around an axis of the shaft portion.

  Exercise equipment is held by hand. The exercise equipment is swung during the swing. When shaken, the posture of the exercise device changes along the time axis. At the start of the swing, the subject determines in advance the posture of the exercise tool at the time of impact. From here, the swing operation including the impact is performed again. In one aspect of the present invention, for example, the relative rotation angle around the axis of the shaft portion of the exercise tool at a certain position during the addressing and during the swing, the relative rotation angle between the first state and the second state during the swing, etc. Detected. If the relative rotation angle is visually displayed on the screen of the display device based on the image data, the rotation around the shaft portion of the exercise tool can be presented to the subject. It is known that the rotation of the shaft portion of the exercise tool affects the direction of the hit ball after impact. The subject can improve the swing form in response to the presented rotation of the shaft portion.

It is a conceptual diagram which shows roughly the structure of the golf swing analyzer which concerns on one Embodiment of this invention. It is a conceptual diagram which shows roughly the relationship between a motion analysis model, a golfer, and a golf club. It is a block diagram which shows roughly the structure of the arithmetic processing circuit which concerns on one Embodiment. It is a figure which shows an example of the image which expresses the movement locus | trajectory of a golf club visually. It is an example of the graph which shows the change of a relative rotation angle according to a time axis. It is a specific example of a pseudo-circular graph that associates an event with a relative rotation angle. It is another specific example of the pseudo | simulation circular graph which links | relates an event with a relative rotation angle.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. The present embodiment described below does not unduly limit the contents of the present invention described in the claims, and all the configurations described in the present embodiment are essential as means for solving the present invention. Not necessarily.

(1) Configuration of Golf Swing Analysis Device FIG. 1 schematically shows the configuration of a golf swing analysis device (motion analysis device) 11 according to an embodiment of the present invention. The golf swing analysis device 11 includes an inertial sensor 12, for example. For example, an acceleration sensor or a gyro sensor is incorporated in the inertial sensor 12. The acceleration sensor can individually detect acceleration in three axial directions orthogonal to each other. The gyro sensor can individually detect the angular velocity around each of three axes orthogonal to each other. The inertial sensor 12 outputs a detection signal. The acceleration and angular velocity are specified for each axis in the detection signal. The acceleration sensor and the gyro sensor detect acceleration and angular velocity information with relatively high accuracy.

  The inertial sensor 12 is attached to a golf club (exercise tool) 13. The golf club 13 includes a shaft 13a and a grip 13b. The grip 13b is gripped by hand. The grip 13b is formed coaxially with the axis of the shaft 13a. A club head 13c is coupled to the tip of the shaft 13a. Desirably, the inertial sensor 12 is attached to the shaft 13 a or the grip 13 b of the golf club 13. The inertial sensor 12 may be fixed to the golf club 13 so as not to be relatively movable. Here, when the inertial sensor 12 is attached, one of the detection axes of the inertial sensor 12 is aligned with the axis of the shaft 13a. It is desirable that the other detection axis of the inertial sensor 12 is aligned with the orientation of the face of the club head 13c.

  The golf swing analysis device 11 includes an arithmetic processing circuit 14. An inertial sensor 12 is connected to the arithmetic processing circuit 14. In connection, a predetermined interface circuit 15 is connected to the arithmetic processing circuit 14. The interface circuit 15 may be connected to the inertial sensor 12 by wire or may be connected to the inertial sensor 12 by wireless. A detection signal is supplied from the inertial sensor 12 to the arithmetic processing circuit 14.

  A storage device 16 is connected to the arithmetic processing circuit 14. The storage device 16 can store, for example, a golf swing analysis software program (motion analysis program) 17 and related data. The arithmetic processing circuit 14 executes a golf swing analysis software program 17 to realize a golf swing analysis method. The storage device 16 can include a DRAM (Dynamic Random Access Memory), a mass storage device unit, a non-volatile memory, and the like. For example, in the DRAM, the golf swing analysis software program 17 is temporarily held when the golf swing analysis method is executed. A golf swing analysis software program 17 and data are stored in a mass storage unit such as a hard disk drive (HDD). The nonvolatile memory stores a relatively small capacity program such as BIOS (basic input / output system) and data.

  An image processing circuit 18 is connected to the arithmetic processing circuit 14. The arithmetic processing circuit 14 sends predetermined image data to the image processing circuit 18. A display device 19 is connected to the image processing circuit 18. In connection, a predetermined interface circuit (not shown) is connected to the image processing circuit 18. The image processing circuit 18 sends an image signal to the display device 19 according to the input image data. An image specified by the image signal is displayed on the screen of the display device 19. The display device 19 is a liquid crystal display or other flat panel display. Here, the arithmetic processing circuit 14, the storage device 16, and the image processing circuit 18 are provided as a computer device, for example.

  An input device 21 is connected to the arithmetic processing circuit 14. The input device 21 includes at least alphabet keys and numeric keys. Character information and numerical information are input from the input device 21 to the arithmetic processing circuit 14. The input device 21 may be composed of a keyboard, for example. The combination of the computer device and the keyboard may be replaced with, for example, a smartphone, a mobile phone terminal, a tablet PC (personal computer), or the like.

(2) Motion analysis model The arithmetic processing circuit 14 defines a virtual space. The virtual space is formed in a three-dimensional space. A three-dimensional space specifies a real space. As shown in FIG. 2, the three-dimensional space has an absolute reference coordinate system (overall coordinate system) Σ _xyz . In the three-dimensional space, a three-dimensional motion analysis model 26 is constructed according to the absolute reference coordinate system Σ _xyz . The rod 27 of the three-dimensional motion analysis model 26 is point-constrained at a fulcrum 28 (coordinate x). The rod 27 operates three-dimensionally as a pendulum around the fulcrum 28. The position of the fulcrum 28 can be moved. Here, as the absolute reference coordinate system sigma _xyz, the position of the center of gravity 29 of the rod 27 is identified by the coordinates _{x g,} the position of the club head 13c can be located at the coordinates _{x h.}

が特定され、角速度信号では角速度ω_１、ω_２が特定される。 The three-dimensional motion analysis model 26 corresponds to a model of the golf club 13 at the time of swing. The pendulum rod 27 projects the shaft 13 a of the golf club 13. The fulcrum 28 of the rod 27 projects the grip 13b. The inertial sensor 12 is fixed to the rod 27. According to the absolute reference coordinate system Σ _xyz, the position of the inertial sensor 12 is specified by the coordinate x _s . The inertial sensor 12 outputs an acceleration signal and an angular velocity signal. In the acceleration signal, the acceleration from which the influence of the gravitational acceleration g is subtracted.

And the angular velocities ω ₁ and ω ₂ are specified in the angular velocity signal.

Similarly, the arithmetic processing circuit 14 fixes the local coordinate system Σ _s to the inertial sensor 12. The origin of the local coordinate system Σ _s is set to the origin of the detection axis of the inertial sensor 12. The y axis of the local coordinate system Σ _s coincides with the axis of the shaft 13a. The x-axis of the local coordinate system Σ _s coincides with the hitting direction specified by the direction of the face (hitting surface). Therefore, the fulcrum position l _sj is specified by (0, l _sji , 0) according to the local coordinate system Σ _s . Similarly, on this local coordinate system Σ _s , the position l _{sg of the} center of gravity 29 is specified by (0, l _sgy , 0), and the position l _sh of the club head 13c is specified by (0, l _shy , 0). .

(3) Configuration of Arithmetic Processing Circuit FIG. 3 schematically shows the configuration of the arithmetic processing circuit 14 according to an embodiment. The arithmetic processing circuit 14 includes a first detection unit 31 and a second detection unit 32. The first detector 31 and the second detector 32 are each connected to the inertial sensor 12. Outputs are supplied from the inertial sensor 12 to the first detector 31 and the second detector 32, respectively.

  The first detector 31 detects the initial position of the grip 13b around the axis of the grip 13b (coaxial to the shaft 13a) based on the output of the inertial sensor 12. In the detection, the first detection unit 31 acquires the angular velocity at the time of addressing around one detection axis (here around the y axis) parallel to the shaft 13a by the inertial sensor 12. The first detection unit 31 sets the acquired angular velocity to an initial value. Since no angular velocity is generated around the y-axis at the time of addressing, the angular position “0 ° (zero degree)” (= initial position) is set when the angular velocity stops at “0 (zero)”. The posture of the shaft 13a at the time of address corresponds to the first state of the shaft portion, and corresponds to a stationary state before the start of the swing operation.

その結果、単位時間で累積される時刻ごとに初期位置からの変化量は算出される。こうして時間軸に従ってグリップ１３ｂの相対回転角θｎは特定される。 The second detector 32 detects the relative rotation angle θn (n = 1,..., N) of the grip 13b around the axis from the initial position of the angular position “0 °” based on the output of the inertial sensor 12. In detection, the second detection unit 32 calculates the amount of change in the rotation angle per unit time. As shown in the following equation, the calculated change amount is accumulated. Here, N indicates the number of samples (hereinafter the same).

As a result, the amount of change from the initial position is calculated for each time accumulated in unit time. Thus, the relative rotation angle θn of the grip 13b is specified along the time axis.

  The arithmetic processing circuit 14 includes a first image data generation unit 33. The first image data generation unit 33 is connected to the second detection unit 32. An output is supplied from the second detection unit 32 to the first image data generation unit 33. The first image data generation unit 33 generates image data. In this image data, an image for visually displaying the relative rotation angle θn is specified. The image data of the first image data generation unit 33 specifies an image that displays a change in the relative rotation angle θn according to the time axis. Such an image may be, for example, a graph in which the time axis is set on the horizontal axis and the relative rotation angle θ is set on the vertical axis. Here, the image data can include comparison data (comparison pattern) to be overlaid on the image. The comparison data shows a comparative example of the change in the relative rotation angle θ. Such comparison data may represent a swing motion of a professional, an advanced player, or another subject having the same skill as the subject.

姿勢検出部３４は算出された加速度に基づきグリップ１３ｂの移動速度を算出する。ここでは、次式に従って加速度に規定のサンプリング間隔ｄｔで積分処理が施される。

さらに姿勢検出部３４は算出された速度に基づきグリップ１３ｂの位置を算出する。ここでは、次式に従って速度に規定のサンプリング間隔ｄｔで積分処理が施される。

同様に、姿勢検出部３４は次式に従ってクラブヘッド１３ｃの位置を検出する。位置の検出にあたって姿勢検出部３４は慣性センサー１２の固有の局所座標系Σ_ｓに従ってクラブヘッド１３ｃの位置ｌ_ｓｈを特定する。特定にあたって姿勢検出部３４は記憶装置１６から位置情報を取得する。記憶装置１６には予めクラブヘッド１３ｃの位置ｌ_ｓｈが格納される。クラブヘッド１３ｃの位置ｌ_ｓｈは例えば入力装置２１経由で指定されればよい。

The arithmetic processing circuit 14 includes an attitude detection unit 34. The posture detection unit 34 is connected to the inertial sensor 12. An output from the inertial sensor 12 is supplied to the posture detection unit 34. Here, the output of the inertial sensor 12 includes acceleration detected along the three orthogonal axes and angular velocity detected around the three orthogonal axes, respectively. The posture detection unit 34 detects the posture of the golf club 13 based on the output of the inertia sensor 12. In detecting the posture, the posture detecting unit 34 detects, for example, the positions of the grip 13b and the club head 13c during movement. In detecting the position, the posture detection unit 34 calculates the acceleration of the grip 13b according to the following equation, for example. In calculating the acceleration, the posture detection unit 34 specifies the position l _{sj of the} grip 13b according to the unique local coordinate system Σ _s of the inertial sensor 12. In specifying, the posture detection unit 34 acquires position information from the storage device 16. The storage device 16 stores in advance the position l _{sj of the} grip 13b. The position lsj of the grip 13b may be specified via the input device 21, for example.

The posture detection unit 34 calculates the moving speed of the grip 13b based on the calculated acceleration. Here, integration processing is performed on the acceleration at a specified sampling interval dt according to the following equation.

Further, the posture detection unit 34 calculates the position of the grip 13b based on the calculated speed. Here, integration processing is performed on the speed at a specified sampling interval dt according to the following equation.

Similarly, the posture detection unit 34 detects the position of the club head 13c according to the following equation. In detecting the position, the posture detection unit 34 specifies the position l _sh of the club head 13 c according to the local coordinate system Σ _s inherent to the inertial sensor 12. In specifying, the posture detection unit 34 acquires position information from the storage device 16. The storage device 16 stores in advance the position l _{sh of the} club head 13c. The position l _sh of the club head 13c may be specified via the input device 21, for example.

  The arithmetic processing circuit 14 includes a swing image data generation unit 35. The swing image data generation unit 35 is connected to the posture detection unit 34. The swing image data generation unit 35 is supplied with the output of the posture detection unit 34. The swing image data generation unit 35 specifies the movement locus of the golf club 13 based on the position of the grip 13b and the position of the club head 13c calculated by the posture detection unit 34. An image expressing the swing motion is generated based on the identified movement trajectory. The image is output from the swing image data generation unit 35 as image data.

  The arithmetic processing circuit 14 includes a stillness detection unit 36. The stationary detection unit 36 is connected to the inertial sensor 12. An output is supplied from the inertial sensor 12 to the stationary detector 36. Here, the output of the inertial sensor 12 includes acceleration detected along the three orthogonal axes and angular velocity detected around the three orthogonal axes, respectively. The stationary detector 36 determines the stationary state of the golf club 13 based on the output of the inertial sensor 12. When the output of the inertial sensor 12 falls below the threshold value, the stillness detection unit 36 determines the resting state of the golf club 13. The resting state of the golf club 13 represents an address during the swing operation. The threshold value may be set to a value that can eliminate the influence of the detection signal indicating minute vibration such as body movement. The stationary detection unit 36 outputs a stationary notification signal when the stationary state is confirmed over a predetermined period. The stationary notification signal is sent to the first detection unit 31, the second detection unit 32, and the posture detection unit 34. The first detection unit 31 sets the initial position of the angular position “0 °” in response to the reception of the stationary notification signal. The second detection unit 32 starts calculating the relative rotation angle in response to receiving the stationary notification signal. The posture detection unit 34 starts detecting the posture of the golf club 13 in response to receiving the stillness notification signal.

  Here, the stillness detection unit 36 may refer to the inclination angle of the golf club 13 when determining the resting state. At this time, the stillness detection unit 36 calculates the tilt angle, that is, the posture of the golf club 13 based on the coordinates of the grip 13b and the coordinates of the club head 13c. The stillness detection unit 36 determines the posture of the golf club 13 at the time of addressing based on the calculated tilt angle. It is determined whether or not the tilt angle falls within a predetermined tilt angle range. The stillness detection unit 36 starts determining the resting state of the golf club 13 after the posture of the golf club 13 at the address is established.

  The arithmetic processing circuit 14 includes an event detection unit 37. The event detection unit 37 is connected to the posture detection unit 34. The event detection unit 37 is supplied with the output of the posture detection unit 34. The event detection unit 37 specifies an event during the swing operation based on the posture of the golf club 13. For example, the event detection unit 37 detects the axis of the grip 13b arranged in parallel with the ground (that is, the axis of the shaft 13a). Thus, the halfway back during the backswing can be specified. For example, the event detection unit 37 can detect a change in acceleration when switching from backswing to downswing. In this way, the top of the backswing is specified. In these detections, the event detection unit 37 may acquire a reference value to be compared from the storage device 16.

  The arithmetic processing circuit 14 includes an arithmetic unit 38. The calculation unit 38 is connected to the event detection unit 37 and the second detection unit 32. The calculation unit 38 is supplied with the output of the event detection unit 37 and the output of the second detection unit 32. The calculation unit 38 associates individual events with the relative rotation angle θn. Events such as halfway back and top are associated with a specific relative rotation angle θn.

  The arithmetic processing circuit 14 includes a second image data generation unit 39. The second image data generation unit 39 is connected to the calculation unit 38. An output is supplied from the calculation unit 38 to the second image data generation unit 39. The second image data generation unit 39 generates image data. In this image data, an image for visually displaying the relative rotation angle θn is specified. The image data of the second image data generation unit 39 specifies an image for displaying the relative rotation angle θn together with the notation of the event. Such an image may be, for example, a pseudo pie chart in which the relative rotation angle θ is specified around the center point. Here, comparison data (comparison pattern) to be overlaid on the image can be included. The comparison data indicates a comparative example of the relative rotation angle θ for each event. Such comparison data may represent a swing motion of a professional, an advanced person, or another subject as described above.

  The arithmetic processing circuit 14 includes a drawing unit 41. The drawing unit 41 is connected to the first image data generation unit 33, the second image data generation unit 39 and the swing image data generation unit 35. The drawing unit 41 is supplied with outputs from the first image data generation unit 33, the second image data generation unit 39 and the swing image data generation unit 35. The drawing unit 41 draws an image that displays the change in the relative rotation angle θn according to the time axis based on the output of the first image data generation unit 33. Similarly, the drawing unit 41 draws an image that displays the relative rotation angle θn together with the event notation based on the output of the second image data generation unit 39. The drawing unit 41 draws an image representing the swing motion based on the output of the swing image data generation unit 35.

(4) Operation of Golf Swing Analysis Device The operation of the golf swing analysis device 11 will be briefly described. First, a golfer's golf swing is measured. Prior to the measurement, necessary information is input from the input device 21 to the arithmetic processing circuit 14. Here, according to the three-dimensional motion analysis model 26, the input of the position l _{sj of the} fulcrum 28 according to the local coordinate system Σ _s and the rotation matrix R ⁰ of the initial posture of the inertial sensor 12 is prompted. The input information is managed under a specific identifier, for example. The identifier may identify a specific golfer.

  Prior to measurement, the inertial sensor 12 is attached to the shaft 13 a of the golf club 13. The inertial sensor 12 is fixed to the golf club 13 so as not to be relatively displaced. Here, one of the detection axes of the inertial sensor 12 is aligned with the axis of the shaft 13a. One of the detection axes of the inertial sensor 12 is adjusted to the hitting direction specified by the direction of the face (hitting surface).

Prior to execution of the golf swing, measurement of the inertial sensor 12 is started. At the start of operation, the inertial sensor 12 is set to a predetermined position and posture. These positions and postures correspond to those specified by the rotation matrix R ⁰ of the initial posture. The inertial sensor 12 continuously measures acceleration and angular velocity at specific sampling intervals. The sampling interval defines the measurement resolution. The detection signal of the inertial sensor 12 is sent to the arithmetic processing circuit 14 in real time. The arithmetic processing circuit 14 receives a signal specifying the output of the inertial sensor 12.

  The golf swing starts at the address, takes back, halfway back, top to down swing, impact, follow through, and finish. The posture of the shaft 13a at the time of an event such as a halfway back or top corresponds to the second state of the shaft portion, and corresponds to the operation state after the start of the swing operation. The golf club 13 is swung. When shaken, the posture of the golf club 13 changes along the time axis. The inertial sensor 12 outputs a detection signal according to the posture of the golf club 13. At this time, the posture detection unit 34 calculates the posture of the golf club 13 along the time axis based on the detection signal during the swing operation. The swing image data generation unit 35 specifies the movement locus of the golf club 13 during the swing operation based on the calculated posture of the golf club 13. The swing image data generation unit 35 generates three-dimensional image data (for example, polygon data) that visually represents a swing motion. The drawing unit 41 draws an image that visually identifies the movement locus 42 of the golf club 13 based on the three-dimensional image data, for example, as shown in FIG. In this way, the swing motion is visually represented by the image. The drawing data is sent to the image processing circuit 18, and the image is displayed on the screen of the display device 19 according to the drawing data.

  In measuring the golf swing, the subject first takes the address posture. At this address, the subject reproduces the posture at the moment of impact. As a result, the posture at the moment of impact is extracted from a series of operations called “golf swing”. At this time, the golf club 13 is held in a stationary posture. The stationary detector 36 detects the stationary state of the golf club 13. The stationary detector 36 outputs a stationary notification signal. The first detection unit 31 sets the initial position of the angular position “0 °” in response to the reception of the stationary notification signal. The second detection unit 32 starts calculating the relative rotation angle in response to receiving the stationary notification signal. The posture detection unit 34 starts detecting the posture of the golf club 13 in response to receiving the stillness notification signal.

  During the swing operation starting from the address, the second detection unit 32 detects the relative rotation angle θn at regular unit time intervals. The relative rotation angle θn of the grip 13b is specified along the time axis. An output signal specifying the relative rotation angle θn is sent to the first image data generation unit 33. The first image data generation unit 33 generates two-dimensional image data that specifies an image for displaying a change in the relative rotation angle θn according to the time axis. Based on the generated two-dimensional image data, the drawing unit 41 draws an image that displays a change in the relative rotation angle θ according to the time axis, for example, as shown in FIG. In this image, lesson professional comparison data 43 is simultaneously drawn. In addition, the graph of the relative rotation angle θ may be displayed on the screen simultaneously with the image of the swing operation shown in FIG.

  The event detection unit 37 specifies an event during the swing operation based on the output of the posture detection unit 34. Here, the event detection unit 37 specifies a halfway back or top during backswing. For example, the event detection unit 37 associates an elapsed time from the address with an event such as a halfway back or top. The halfway back and top specified in this way are output as data together with a time stamp.

  The output of the event detection unit 37 is sent to the calculation unit 38. An output signal for specifying the relative rotation angle θn is sent from the second detector 32 to the calculator 38. The calculation unit 38 associates an event such as a halfway back or top with a specific relative rotation angle θ. The data of the relative rotation angle θ associated with the event is sent to the second image data generation unit 39. The second image data generation unit 39 generates two-dimensional image data that specifies an image for displaying the relative rotation angle θ together with the event description. At this time, the second image data generation unit 39 attaches “Address (address)” to the initial position of the relative rotation angle θ. The notation “Halfway Back” is attached to the position of the relative rotation angle θ corresponding to the half way back. The notation “Top” is attached to the position of the relative rotation angle θ corresponding to the top. The position where the relative rotation angle θ shows the maximum value is marked with “Max”. For example, as illustrated in FIG. 6, the drawing unit 41 draws an image in which the events “Address”, “Halfway Back”, “Top”, and “Max” are associated with the relative rotation angle θ, based on the generated two-dimensional image data. . In this pseudo circular graph, the center angle “0 °” is indicated by “Address”, and the relative rotation angle θ is displayed clockwise therefrom. One round from “Address” and then back to “Address” corresponds to 360 °. In this image, lesson professional comparison data 44 is simultaneously drawn. In addition, as shown in FIG. 7, the comparison data may be omitted and only the relative rotation angle θ of the subject may be drawn on the pseudo-circular graph. In addition, the relative rotation angle θn and the event graph may be displayed on the screen simultaneously with the image of the swing operation shown in FIG.

  When starting the swing, the subject determines in advance the posture of the golf club 13 at the time of impact. From here, the swing operation including the impact is performed again. During the swing operation, the relative rotation angle of the grip 13b is detected around the axis of the grip 13b. Based on the output of the first image data generation unit 33 and the output of the second image data generation unit 39, the relative rotation angle θ is visually displayed on the screen of the display device 19. Thus, the rotation of the grip 13b around the axis is presented to the subject. It is known that the rotation of the grip 13b affects the direction of the hit ball after impact. The subject can improve the swing form according to the rotation of the presented grip 13b.

  In particular, according to the output of the first image data generation unit 33, the change of the relative angular position is visually presented according to the time axis, so that the subject intuitively recognizes the degree of change and the speed of change. Can do. In accordance with such perception, the subject can make improvements to the swing form. On the other hand, according to the output of the second image data generating unit 39, events such as address, halfway back, and top are visually presented for each angle of the relative angle position. The relationship between the position and the event can be recognized. Based on such recognition, the subject can make improvements to the swing form. In the half way back, the axis of the grip 13b is oriented parallel to the ground, so the event detection unit 37 can specify the angular position of the half way back. Based on these indicators, the subject can make improvements to the swing form.

  In addition, in an image corresponding to a time axis or a pseudo-circular graph image, the swing motion of professionals and advanced players is expressed by comparison data. Thus, the change in the relative rotation angle θ of the subject is compared with the change in the relative rotation angle of the professional or the expert, and the relative rotation angle θ of the subject is compared with the relative rotation angle of the professional or the expert for each event. Depending on the comparison, the subject can make improvements to the swing form.

  The inertial sensor 12 detects the relative rotation angle of the grip 13b if at least the angular velocity around the shaft portion of the exercise tool is detected. If the inertial sensor 12 detects acceleration along the three orthogonal axes and detects the angular velocity around the three orthogonal axes, the posture of the golf club 13 is detected by one inertial sensor 12.

  In the above embodiment, each functional block of the arithmetic processing circuit 14 is realized in accordance with the execution of the golf swing analysis software program 17. However, each functional block may be realized by hardware without depending on software processing.

  In the above embodiment, in the golf swing, the relative rotation between the face angle of the shaft 13a or the club head 13c of the golf club 13 at the time of address and the face angle of the shaft 13a or the golf club 13 at a certain timing during the golf swing. Although the angle has been described, a relative rotation angle with the face angle of the shaft 13a or the golf club at two points at a certain timing during the swing may be calculated. In addition to the detection of the rotation angle around the axis of the shaft portion of the exercise tool, the relative rotation angle of an axis other than the axis of the shaft portion may be obtained and displayed together with the rotation angle around the axis of the shaft portion. Further, the relative rotation angle of an axis other than the axis of the shaft portion may be obtained and displayed without using the detection of the rotation angle around the shaft portion of the exercise tool. Further, the present invention can be applied not only to golf swings but also to analysis of exercises (for example, tennis, baseball, etc.) that perform a swing motion using exercise equipment.

  Although the present embodiment has been described in detail as described above, it will be easily understood by those skilled in the art that many modifications can be made without substantially departing from the novel matters and effects of the present invention. Therefore, all such modifications are included in the scope of the present invention. For example, a term described with a different term having a broader meaning or the same meaning at least once in the specification or the drawings can be replaced with the different term in any part of the specification or the drawings. Further, the configurations and operations of the inertial sensor 12, the arithmetic processing circuit 14, the three-dimensional motion analysis model 26, and the like are not limited to those described in the present embodiment, and various modifications can be made.

  DESCRIPTION OF SYMBOLS 11 Motion analysis apparatus (golf swing analysis apparatus), 12 Inertial sensor, 13 Exercise equipment (golf club), 13a Shaft part (shaft), 14 Computer (arithmetic processing circuit), 17 Motion analysis program (golf swing analysis software program), 19 1st display part or 2nd display part (display device), 31 1st detection part, 32 2nd detection part, 33 1st image data generation part, 37 Event detection part, 38 operation part, 39 2nd image data generation Part, 43 comparison data, 44 comparison data.

Claims (11)

A first detection unit for detecting a first state of the shaft portion of the exercise tool using an output of the inertial sensor;
A second detection for detecting a second state of the shaft portion of the exercise tool using an output of the inertial sensor and detecting a relative rotation angle of the shaft portion changed around the shaft portion from the first state. And
A motion analysis apparatus comprising: The motion analysis apparatus according to claim 1,
The motion analysis apparatus according to claim 1, wherein the first state is a stationary state before the start of the swing motion, and the second state is an motion state after the swing motion is started. The motion analysis apparatus according to claim 1 or 2,
The first detection unit specifies the direction of the striking surface of the exercise tool in the first state,
The motion analysis apparatus characterized in that the second detection unit specifies the direction of the striking surface of the exercise tool in the second state. In the kinematic analysis device according to any one of claims 1 to 3,
A motion analysis apparatus comprising: a first display unit that displays the relative rotation angle. The motion analysis apparatus according to claim 4,
The first display unit displays a change in the relative rotation angle according to a time during a swing operation of the exercise tool. The motion analysis apparatus according to claim 4 or 5,
The first display unit displays the comparison data of the change in the relative rotation angle together. In the kinematic analysis device according to any one of claims 1 to 6,
The inertial sensor includes a detection axis parallel to an axis of the shaft portion of the exercise tool, and detects an angular velocity generated around the axis. In the kinematic analysis device according to any one of claims 1 to 5,
Using the output of the inertial sensor, an event detection unit that identifies an event during a swing motion;
A motion analysis apparatus comprising: a calculation unit that associates the relative rotation angle with the event. The motion analysis apparatus according to claim 8,
A motion analysis apparatus comprising: a second display unit that displays the relative rotation angle together with the notation of the event. The motion analysis apparatus according to claim 8 or 9,
The second display unit also displays the relative rotation angle comparison data for each event. Detecting the first state of the shaft portion of the exercise tool using the output of the inertial sensor;
Detecting the second state of the shaft portion of the exercise tool using the output of the inertial sensor;
A motion analysis program for causing a computer to execute a procedure for detecting a relative rotation angle between the first state and the second state of the shaft portion that changes around an axis of the shaft portion.

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