JP6029097B2 - Golf swing analysis apparatus and golf swing analysis method - Google Patents

Description

  The present invention relates to a golf swing analysis device, a golf swing analysis method, and the like.

  For example, a golf swing analysis device as disclosed in Patent Document 1 is generally known. The golf swing analyzer uses an optical motion capture system, which captures a golfer's swing. When shooting, a marker is fixed at a specific position of a golfer or a golf club, and the movement locus of the specific position is recorded by shooting the movement of the marker. Further, as disclosed in, for example, Patent Document 2, a golf swing analysis device that uses an acceleration sensor is also generally known. An acceleration sensor is attached to the golf club, and a golf swing form is analyzed according to the acceleration measured by the acceleration sensor.

JP 2010-11926 A JP-A-11-169499

In golf swing analysis using an optical motion capture system as described in Patent Document 1, since the equipment is large and measurement in the field is difficult, the acceleration sensor as described in Patent Document 2 In recent years, golf swing analysis using an inertial sensor such as the above has been used. However, in the golf swing analysis using the inertial sensor, the relative angle between the arm and the golf club cannot be presented to the user well.

  According to at least one aspect of the present invention, a golf swing analysis device, a golf swing analysis method, and the like that can effectively present a relative angle between an arm and a golf club to a user can be provided.

  (1) One aspect of the present invention is based on a first inertia sensor attached to a golfer's upper body part, a second inertia sensor attached to a golf club, and outputs of the first inertia sensor and the second inertia sensor. The present invention relates to a golf swing analysis apparatus comprising: a calculation unit that calculates a relative angle between the first inertia sensor and the second inertia sensor.

  In the golf swing, it is desired that the relative angle is fixed between the arm and the golf club in the initial stage from the top. It is believed that the head speed can be increased if the force to fix the angle is relaxed prior to impact and the natural rotation of the golf club relative to the arm is achieved. The golf swing analyzing apparatus can present the relative angle between the arm and the golf club to the user. If the relative angle between the arm and the golf club is observed in this way, a golf swing form capable of efficiently transmitting energy to the golf club can be derived. Thus, an indication can be provided regarding the form of the golf swing. For example, by repeatedly changing and observing the form, good improvements can be made to the golf swing form through trial and error.

  (2) The golf swing analyzing apparatus may further include an image data generating unit that generates image data for visualizing the change in the relative angle along the time axis. The user can be presented with a timing to visually relax. Thus, an indication can be provided regarding the form of the golf swing. For example, by repeatedly changing and observing the form, good improvements can be made to the golf swing form through trial and error.

  (3) In calculating the relative angle, a three-dimensional double pendulum model is used, the upper body part can form a first link of the three-dimensional double pendulum model, and the golf club has the third order A second link of the original double pendulum model can be formed. Thus, the golf swing is modeled. The three-dimensional double pendulum model can dynamically reproduce a golf swing with relatively high accuracy. Thus, the golf swing can be effectively analyzed.

  (4) The fulcrum of the first link can be located at the center of the line connecting both shoulders of the golfer, and the joint of the first link and the second link can be located at the grip of the golf club. . Thus, the golf swing can be analyzed with high accuracy.

  (5) The first inertia sensor and the second inertia sensor may include an acceleration sensor having a plurality of detection axes and a gyro sensor having a plurality of detection axes. According to the acceleration sensor and the gyro sensor, information on acceleration and angular velocity can be accurately detected when calculating the relative angle.

  (6) The golf swing analyzing apparatus may further include an energy change rate inversion detection unit that specifies a positive / negative balance of the total energy change rate of the part of the upper body. If a zero crossing of the total energy change rate is observed in this way, a golf swing form that can efficiently transmit energy to the golf club can be derived. Thus, an indication can be provided regarding the form of the golf swing. For example, by repeatedly changing and observing the form, good improvements can be made to the golf swing form through trial and error. In particular, good improvements can be made to the golf swing form if the timing of the zero crossing is associated with the change in relative angle.

  (7) In another aspect of the present invention, the first inertia sensor and the second inertia sensor based on outputs of a first inertia sensor attached to a golfer's upper body and a second inertia sensor attached to a golf club. The present invention relates to a golf swing analysis method for calculating a relative angle between the two.

  In the golf swing, the relative angle is fixed between the arm and the golf club in the initial stage from the top. It is believed that the head speed can be increased if the force to fix the angle is relaxed prior to impact and the natural rotation of the golf club relative to the arm is achieved. The golf swing analysis method can present the relative angle between the arm and the golf club to the user. If the relative angle between the arm and the golf club is observed in this way, a golf swing form capable of efficiently transmitting energy to the golf club can be derived. Thus, an indication can be provided regarding the form of the golf swing. For example, by repeatedly changing and observing the form, good improvements can be made to the golf swing form through trial and error.

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 three-dimensional double pendulum model, a golfer, and a golf club. It is a block diagram which shows roughly the structure of a part of arithmetic processing circuit. It is a block diagram which shows the structure of an arithmetic processing circuit partially. It is a graph which shows the time series change of the relative angle of a lower arm and a golf club, as a result of lesson professional swing analysis. It is a graph which shows the time series change of the relative angle of a lower arm and a golf club, as a result of swing analysis of an amateur golfer. It is a result of a lesson professional's swing analysis, and is a graph which shows the time-sequential change of a total energy change rate signal. It is a conceptual diagram which shows the attitude | position of a lesson pro and a golf club at the timing of a zero cross. It is a graph which shows the time series change of the total energy change rate signal as a result of swing analysis of an amateur golfer. It is a conceptual diagram which shows the attitude | position of an amateur golfer and a golf club at the timing of a zero cross.

  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 a configuration of a golf swing analysis device 11 according to an embodiment of the present invention. The golf swing analysis device 11 includes, for example, a first inertia sensor 12 and a second inertia sensor 13. The first and second inertial sensors 12, 13 incorporate an acceleration sensor and a gyro sensor. The acceleration sensor can individually detect acceleration in three orthogonal directions. The gyro sensor can individually detect the angular velocity around each of three orthogonal axes. The first and second inertial sensors 12 and 13 output detection signals. 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 first inertial sensor 12 is attached to a golfer's upper limb (for example, a left arm for right-handed driving) 15. Here, although the first inertial sensor 12 is attached to the golfer's forearm, the first inertial sensor 12 may be attached to the upper arm of the golfer. The second inertial sensor 13 is attached to the golf club 14. Desirably, the second inertial sensor 13 is attached to the grip or shaft of the golf club 14. The first and second inertial sensors 12 and 13 may be fixed to the upper limb 15 and the golf club 14 so as not to move relative to each other. Here, when attaching the second inertial sensor 13, one of the detection axes of the second inertial sensor 13 is aligned parallel to the long axis of the golf club 14. In the present embodiment, the first inertial sensor 12 is attached to the upper limb 15, but the first inertial sensor 12 may be attached to the upper body (particularly both shoulders).

  The golf swing analysis device 11 includes an arithmetic processing circuit 16. First and second inertial sensors 12 and 13 are connected to the arithmetic processing circuit 16. In connection, a predetermined interface circuit 17 is connected to the arithmetic processing circuit 16. The interface circuit 17 may be connected to the inertial sensors 12 and 13 in a wired manner or may be connected to the inertial sensors 12 and 13 in a wireless manner. Detection signals are input from the inertial sensors 12 and 13 to the arithmetic processing circuit 16.

  A storage device 18 is connected to the arithmetic processing circuit 16. The storage device 18 stores, for example, a golf swing analysis software program 19 and related data. The arithmetic processing circuit 16 executes a golf swing analysis software program 19 to realize a golf swing analysis method. The storage device 18 includes a DRAM (Dynamic Random Access Memory), a mass storage device unit, a nonvolatile memory, and the like. For example, in the DRAM, the golf swing analysis software program 19 is temporarily stored when the golf swing analysis method is executed. A golf swing analysis software program 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 21 is connected to the arithmetic processing circuit 16. The arithmetic processing circuit 16 sends predetermined image data to the image processing circuit 21. A display device 22 is connected to the image processing circuit 21. In connection, a predetermined interface circuit (not shown) is connected to the image processing circuit 21. The image processing circuit 21 sends an image signal to the display device 22 according to the input image data. An image specified by the image signal is displayed on the screen of the display device 22. The display device 22 is a liquid crystal display or other flat panel display. Here, the arithmetic processing circuit 16, the storage device 18, and the image processing circuit 21 are provided as a computer device, for example.

  An input device 23 is connected to the arithmetic processing circuit 16. The input device 23 includes at least alphabet keys and numeric keys. Character information and numerical information are input from the input device 23 to the arithmetic processing circuit 16. The input device 23 may be composed of a keyboard, for example.

(2) Three-dimensional double pendulum model The arithmetic processing circuit 16 defines a virtual space. The virtual space is formed in a three-dimensional space. As shown in FIG. 2, the three-dimensional space has an absolute reference coordinate system Σ _xyz . A three-dimensional double pendulum model 31 is constructed in the three-dimensional space according to the absolute reference coordinate system Σ _xyz . The three-dimensional double pendulum model 31 includes a first link 32 and a second link 33. The first link 32 is point-constrained at a fulcrum 34 (coordinate x ₀ ). Accordingly, the first link 32 operates as a pendulum three-dimensionally around the fulcrum 34. The position of the fulcrum 34 can be moved. The second link 33 is point-constrained to the first link 32 by a joint 35 (coordinate x ₁ ). Therefore, the second link 33 can operate as a pendulum with respect to the first link 32 around the joint 35. In the three-dimensional double pendulum model 31, the masses m ₁ and m _{2 of} the first and second links 32 and 33, the inertia tensor J ₁ around the fulcrum 34 of the first link 32, and the joint of the second link 33 it is necessary to identify the 35 around the inertia tensor J _2. Here, according to the absolute reference coordinate system Σ _xyz , the position of the center of gravity 36 of the first link 32 is specified by the coordinate x _g1 , the position of the center of gravity 37 of the second link 33 is specified by the coordinate x _g2 , and the position of the club head 38 Is specified by coordinates _xh2 .

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 double pendulum model 31 corresponds to a model of the golfer G and the golf club 14. The fulcrum 34 of the first link 32 projects the center position of both shoulders of the upper body of the golfer G. The joint 35 projects a grip. The second link 33 projects the golf club 14. The first inertial sensor 12 is fixed to the upper limb 15 of the golfer. The center positions of both shoulders can be fixed relative to the first inertial sensor 12. According to the absolute reference coordinate system Σ _xyz, the position of the first inertial sensor 12 is specified by the coordinate x _s1 . The second inertial sensor 13 is fixed to the second link 33. According to the absolute reference coordinate system Σ _xyz, the position of the second inertial sensor 13 is specified by the coordinate x _s2 . The first inertia sensor 12 and the second inertia sensor 13 output an acceleration signal and an angular velocity signal, respectively. In the acceleration signal, the acceleration including the influence of gravity acceleration g

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

The arithmetic processing circuit 16 fixes the local coordinate system Σ _s1 to the first inertial sensor 12. The origin of the local coordinate system Σ _s1 is set to the origin of the detection axis of the first inertial sensor 12. A joint 35 is set on the y-axis of the local coordinate system Σ _s1 . Therefore, the position l _sj1 of the joint 35 on the local coordinate system Σ _s1 is specified by (0, l _sj1y , 0). Similarly, the position l _s0 of the fulcrum 34 on the local coordinate system Σ _s1 and the position l _{sg1 of the} center of gravity 36 are _specified by (l _s0x , l _s0y , l _s0z ) and (l _sg1x , l _sg1y , l _sg1z ), _{respectively.} The

Similarly, the arithmetic processing circuit 16 fixes the local coordinate system Σ _s2 to the second inertial sensor 13. The origin of the local coordinate system Σ _s2 is set to the origin of the detection axis of the second inertial sensor 13. The y axis of the local coordinate system Σ _s2 coincides with the axis of the golf club 14. Therefore, the position l _{sj2 of the} joint 35 is specified by (0, l _sj2y , 0) according to the local coordinate system Σ _s2 . Similarly, the position _{l sg2} of the center of gravity 37 is on this local coordinate system sigma _s2 are identified by _{(0, l sg2y, 0)} , the position is the position _{l sh2} of the club head 38 is identified by _{(0, l sh2y, 0)} Is done.

(3) Configuration of Arithmetic Processing Circuit FIG. 3 schematically shows the configuration of the arithmetic processing circuit 16. The arithmetic processing circuit 16 includes an element calculation unit 44. An acceleration signal and an angular velocity signal are input to the element calculation unit 44 from the first inertia sensor 12 and the second inertia sensor 13. The element calculation unit 44 calculates a component value required for calculating the energy change rate based on the acceleration and the angular velocity. In the calculation, the element calculation unit 44 acquires various numerical values from the storage device 18.

このとき、

は第２リンク３３の重心３７の加速度を示す。定数ｇは重力加速度を示す。重心３７の加速度は第２慣性センサー１３の計測値から算出される。第１力演算部４５は第１関節間力信号を出力する。第１関節間力信号で第１関節間力Ｆ_２の値は特定される。 The element calculation unit 44 includes a first force calculation unit 45. The first force calculation unit 45 calculates a first joint force F ₂ acting on the second link 33. In the calculation, the first force calculation unit 45 acquires the acceleration signal of the second inertial sensor 13 and the first mass data of the golf club 14. In the first mass data, the mass m ₂ of the golf club 14 is described. The first mass data may be stored in the storage device 18 in advance. First joint force F ₂ in accordance with the following equation is calculated.

At this time,

Indicates the acceleration of the center of gravity 37 of the second link 33. The constant g indicates the gravitational acceleration. The acceleration of the center of gravity 37 is calculated from the measured value of the second inertial sensor 13. The first force calculation unit 45 outputs a first joint force signal. The first value of the joint contact force F ₂ in the first joint force signal is specified.

このとき、

は第１リンク３２の重心３６の加速度を示す。重心３６の加速度は第１慣性センサー１２の計測値から算出される。第２力演算部４６は第２関節間力信号を出力する。第２関節間力信号で第２関節間力Ｆ_１の値は特定される。 The element calculation unit 44 includes a second force calculation unit 46. The second force calculation unit 46 calculates a second joint force F ₁ acting on the first link 32. In the calculation, the second force calculation unit 46 acquires the acceleration signal, the second mass data, and the first joint force signal of the first inertial sensor 12. The mass m _{1 of the} upper limb 15 is described in the second mass data. The second mass data may be stored in the storage device 18 in advance. Second joint force F ₁ in accordance with the following equation is calculated.

At this time,

Indicates the acceleration of the center of gravity 36 of the first link 32. The acceleration of the center of gravity 36 is calculated from the measured value of the first inertial sensor 12. The second force calculation unit 46 outputs a second joint force signal. The second value of the joint contact force F ₁ in the second joint contact force signal is specified.

ここで、単位ベクトルｅ_ｌ２はゴルフクラブ１４のグリップエンドからクラブヘッドに向いた長軸方向を特定する。第１トルク演算部４７は第１トルク信号を出力する。第１トルク信号でトルクτ_２の値は特定される。 The element calculation unit 44 includes a first torque calculation unit 47. The first torque calculator 47 calculates a torque τ ₂ that acts on the second link 33 around the joint 35. In the calculation, the first torque calculator 47 acquires the angular velocity signal, the first inertia tensor data, the first position data, the second position data, and the first joint force signal of the second inertial sensor 13. The first inertia tensor data inertia tensor J ₂ of the golf club 14 is described. In the first position data, the position l _sj2 of the joint 35 on the local coordinate system Σ _s2 is described. In the second position data, the position l _sg2 of the center of gravity 37 on the local coordinate system Σ _s2 is described. The first inertia tensor data, the first position data, and the second position data may be stored in the storage device 18 in advance. The first joint force signal may be sent from the first force calculation unit 45. Torque τ ₂ is calculated according to the following equation.

Here, the unit vector _e12 specifies the major axis direction from the grip end of the golf club 14 toward the club head. The first torque calculator 47 outputs a first torque signal. The value of the torque τ ₂ is specified by the first torque signal.

ここで、単位ベクトルｅ_ｌ１は第１リンク３２の長軸方向を特定する。第２トルク演算部４８は第２トルク信号を出力する。第２トルク信号でトルクτ_１の値は特定される。 The element calculation unit 44 includes a second torque calculation unit 48. The second torque calculator 48 calculates a torque τ ₁ acting on the first link 32 around the fulcrum 34. In the calculation, the second torque calculation unit 48 calculates the angular velocity signal of the first inertial sensor 12, the second inertia tensor data, the third position data, the fourth position data, the fifth position data, the first joint force signal, and the second joint force. A force signal and a first torque signal are obtained. The second inertia tensor data inertia tensor J ₁ of the upper limb 15 is described. In the third position data, a position l _s0 of the fulcrum 34 on the local coordinate system Σ _s1 is described. In the fourth position data, the position l _sj1 of the joint 35 on the local coordinate system Σ _s1 is described. In the fifth position data, the position l _sg1 of the center of gravity 36 on the local coordinate system Σ _s1 is described. The second inertia tensor data and the third to fifth position data may be stored in the storage device 18 in advance. The first joint force signal may be sent from the first force calculation unit 45. The second joint force signal may be sent from the second force calculation unit 46. The first torque signal may be sent from the first torque calculator 47. Torque τ ₁ is calculated according to the following equation.

Here, the unit vector e ₁₁ specifies the major axis direction of the first link 32. The second torque calculator 48 outputs a second torque signal. The value of the torque τ ₁ is specified by the second torque signal.

算出された加速度は次式に従って積分される。

その結果、支点３４（座標ｘ_０）の移動速度は算出される。ただし、初期速度はゼロとする。第１速度演算部４９は第１速度信号を出力する。第１速度信号で支点３４の移動速度が特定される。 The element calculation unit 44 includes a first speed calculation unit 49. The first speed calculation unit 49 calculates the moving speed of the fulcrum 34. In the calculation, the first speed calculation unit 49 acquires the acceleration signal, angular velocity signal, and third position data of the first inertial sensor 12. The first speed calculator 49 calculates the acceleration of the fulcrum 34 according to the following equation.

The calculated acceleration is integrated according to the following equation.

As a result, the moving speed of the fulcrum 34 (coordinate x ₀ ) is calculated. However, the initial speed is zero. The first speed calculation unit 49 outputs a first speed signal. The moving speed of the fulcrum 34 is specified by the first speed signal.

算出された加速度は次式に従って積分される。

その結果、関節３５（座標ｘ_１）の移動速度は算出される。ただし、初期速度はゼロとする。第２速度演算部５１は第２速度信号を出力する。第２速度信号で関節３５の移動速度は特定される。 The element calculation unit 44 includes a second speed calculation unit 51. The second speed calculation unit 51 calculates the moving speed of the joint 35. In the calculation, the second speed calculation unit 51 acquires the acceleration signal, the angular speed signal, and the fourth position data of the first inertial sensor 12. The 2nd speed calculating part 51 calculates the acceleration of the joint 35 according to following Formula.

The calculated acceleration is integrated according to the following equation.

As a result, the moving speed of the joint 35 (coordinate x ₁ ) is calculated. However, the initial speed is zero. The second speed calculation unit 51 outputs a second speed signal. The moving speed of the joint 35 is specified by the second speed signal.

  The arithmetic processing circuit 16 includes an energy change rate calculation unit 52. An angular velocity signal is supplied from the first inertia sensor 12 and the second inertia sensor 13 to the energy change rate calculation unit 52. Similarly, the energy change rate calculation unit 52 receives the first and second joint force signals, the first and second torque signals, and the first and second speed signals from the element calculation unit 44. The energy change rate calculation unit 52 calculates several energy change rates based on these signals.

第１エネルギーはゴルファーＧのスイング動作で上肢１５に流入するエネルギーに相当する。第１演算部５３は第１エネルギー変化率信号を出力する。第１エネルギー変化率信号で第１エネルギー量のエネルギー変化率が特定される。 The energy change rate calculation unit 52 includes a first calculation unit 53. The first calculator 53 calculates the energy change rate of the first energy generated by the upper limb 15 of the golfer G. In the calculation, the first calculation unit 53 acquires the second torque signal from the element calculation unit 44 and acquires the angular velocity signal from the first inertial sensor 12. Based on the torque τ ₁ and the angular velocity ω ₁ , the energy change rate of the first energy amount is calculated according to the following equation.

The first energy corresponds to the energy that flows into the upper limb 15 by the swing motion of the golfer G. The first calculation unit 53 outputs a first energy change rate signal. The energy change rate of the first energy amount is specified by the first energy change rate signal.

第２演算部５５は第２エネルギー変化率信号を出力する。第２エネルギー変化率信号で第２エネルギー量のエネルギー変化率が特定される。 The energy change rate calculation unit 52 includes a second calculation unit 55. The second calculator 55 calculates an energy change rate of the second energy amount transmitted from the upper limb 15 of the golfer G to the golf club 14. In the calculation, the second calculation unit 55 acquires the first joint force signal and the second speed signal from the element calculation unit 44. Energy change rate of the second energy amount based on the movement speed of the first joint force F ₂ and the joint 35 is calculated according to the following formula.

The second calculator 55 outputs a second energy change rate signal. The energy change rate of the second energy amount is specified by the second energy change rate signal.

第３演算部５７は第３エネルギー変化率信号を出力する。第３エネルギー変化率信号で第３エネルギー量のエネルギー変化率が特定される。 The energy change rate calculation unit 52 includes a third calculation unit 57. The third calculator 57 calculates the energy change rate of the third energy amount derived from the upper limb 15 of the golfer G, that is, the second joint force F ₁ of the first link 32. In the calculation, the third calculation unit 57 acquires the second joint force signal and the first speed signal from the element calculation unit 44. The energy change rate of the third energy amount is calculated according to the following equation.

The 3rd calculating part 57 outputs a 3rd energy change rate signal. The energy change rate of the third energy amount is specified by the third energy change rate signal.

第４演算部５８は第４エネルギー変化率信号を出力する。第４エネルギー変化率信号で第４エネルギー量のエネルギー変化率が特定される。 The energy change rate calculation unit 52 includes a fourth calculation unit 58. The fourth computing unit 58 calculates the energy change rate of the fourth energy amount derived from the torque τ ₂ acting on the golf club 14. In the calculation, the fourth calculation unit 58 acquires the first torque signal from the element calculation unit 44 and acquires the angular velocity signal from the first inertial sensor 12. The energy change rate of the fourth energy amount is calculated according to the following equation.

The fourth calculation unit 58 outputs a fourth energy change rate signal. The energy change rate of the fourth energy amount is specified by the fourth energy change rate signal.

エネルギー変化率反転検出部６１はゼロクロス信号を出力する。ゼロクロス信号で総エネルギー変化率の時系列変化が特定される。時系列変化に基づきゼロクロスのタイミングは特定される。 The arithmetic processing circuit 16 includes an energy change rate inversion detection unit 61. The energy change rate inversion detection unit 61 identifies the zero cross timing of the total energy change rate signal. The zero crossing referred to here is the timing when the value of the total energy change rate signal passes “0 (zero)”, the timing when the value of the total energy change rate signal changes from positive to negative, or the plus of the total energy change rate. It means the timing to specify the negative balance. The total energy change rate is formed based on the energy change rate of the first energy amount, the energy change rate of the second energy amount, the energy change rate of the third energy amount, and the energy change rate of the fourth energy amount according to the following equation: .

The energy change rate inversion detection unit 61 outputs a zero cross signal. A time-series change of the total energy change rate is specified by the zero cross signal. The zero crossing timing is specified based on the time series change.

  The arithmetic processing circuit 16 includes an image data generation unit 62. The image data generation unit 62 is connected to the energy change rate inversion detection unit 61. The zero cross signal is input from the energy change rate inversion detection unit 61 to the image data generation unit 62. The image data generation unit 62 generates first image data for visualizing the total energy change rate signal in time series based on the zero cross signal. The first image data is output toward the image processing circuit 21.

ここで、

は（ｔ＋１）時点での角速度を示し、ｄｔは第１慣性センサー１２のサンプリング間隔に該当する。第１姿勢演算部６５は第１姿勢データを出力する。第１姿勢データは絶対基準座標系Σ_ｘｙｚに従って第１慣性センサー１２の姿勢を記述する回転行列Ｒ_Ｓ１を特定する。 As shown in FIG. 4, the arithmetic processing circuit 16 further includes a first posture calculation unit 65 and a second posture calculation unit 66. The first attitude calculation unit 65 calculates the attitude of the first inertial sensor 12. In the calculation, an angular velocity signal is supplied from the first inertial sensor 12 to the first attitude calculation unit 65. In generating the angular velocity signal, a detection axis is established in the first inertial sensor 12 in accordance with an orthogonal three-axis sensor coordinate system. The angular velocity signal specifies an angular velocity ω _x around the x axis, an angular velocity ω _y around the y axis, and an angular velocity ω _z around the z axis according to the sensor coordinate system. The first inertial sensor 12 expresses the posture change of the first inertial sensor 12 as a rotation matrix every unit time. For example, if the posture at time t is represented by a rotation matrix R ^t , the posture at the next time (t + 1) is represented by the rotation matrix R ^{t + 1} according to the following equation.

here,

Indicates the angular velocity at time (t + 1), and dt corresponds to the sampling interval of the first inertial sensor 12. The first attitude calculation unit 65 outputs first attitude data. The first attitude data specifies a rotation matrix R _S1 that describes the attitude of the first inertial sensor 12 according to the absolute reference coordinate system Σ _xyz .

Initial posture data is supplied to the first posture calculation unit 65 in calculating the posture of the first inertial sensor 12. The initial attitude data can be stored in the storage device 18. The initial attitude data specifies the rotation matrix R ⁰ of the initial attitude. This rotation matrix R ⁰ represents the initial posture of the first inertial sensor 12. The rotation matrix R ⁰ describes the relationship between the absolute reference coordinate system Σ _xyz and the sensor coordinate system. The coordinate value of the sensor coordinate system can be converted into the coordinate value of the absolute reference coordinate system Σ _xyz by the action of the rotation matrix R ⁰ . Orientation of the rotation matrix R ⁰ and (t + 1) as the absolute reference coordinate system sigma _xyz by the product of the rotation matrix R ^{t + 1} of point in time the first inertial sensor 12 in the initial position may be specified in a time sequence. The rotation matrix R ⁰ of the initial posture is determined from the posture of the first inertial sensor 12 at the start of the swing. Here, a predetermined set value is applied to the rotation matrix R ⁰ of the initial posture. In addition, the initial posture of the first inertial sensor 12 may be determined based on the elevation angle and the azimuth angle. The elevation angle can be determined based on the output of the acceleration sensor, for example, and the azimuth angle can be determined based on the output of the magnetic sensor, for example.

Similar to the first posture calculation unit 65, the second posture calculation unit 66 calculates the posture of the second inertial sensor 13. The second posture calculation unit 66 outputs second posture data. The second attitude data specifies a rotation matrix R _S2 that describes the attitude of the second inertial sensor 13 according to the absolute reference coordinate system Σ _xyz .

第１および第２ベクトル演算部６７、６８はそれぞれベクトルデータを出力する。ベクトルデータは第１および第２慣性センサー１２、１３のｙ軸方向のベクトルｒ_１、ｒ_２を特定する。 The arithmetic processing circuit 16 includes a first vector calculation unit 67 and a second vector calculation unit 68. The output of the first attitude calculation unit 65 is supplied to the first vector calculation 67 unit. The second vector calculation unit 68 is supplied with the output of the second attitude calculation unit 66. The first and second vector calculators 67 and 68 calculate vectors r ₁ and r ₂ in the y-axis direction of the first and second inertial sensors 12 and 13 based on the rotation matrices R _S1 and R _S2 , respectively, according to the following equations.

The first and second vector calculation units 67 and 68 each output vector data. The vector data specifies vectors r ₁ and r ₂ in the y-axis direction of the first and second inertial sensors 12 and 13.

相対角度演算部６９は相対角度データを出力する。相対角度データは絶対基準座標系Σ_ｘｙｚに従って相対角度θを特定する。相対角度データは画像処理部６１に供給される。画像処理部６１は、時間軸に沿って相対角度θの変化を視覚化する第２画像データを生成する。 The arithmetic processing circuit 16 includes a relative angle calculation unit 69. The relative angle calculation unit 69 is supplied with vector data from the first and second vector calculation units 67 and 68. The relative angle calculating unit 69 identifies the relative angle θ between the vectors r ₁ and vector r ₂ according to the following equation on the basis of the vector r _1, r _2.

The relative angle calculation unit 69 outputs relative angle data. The relative angle data specifies the relative angle θ according to the absolute reference coordinate system _Σxyz . The relative angle data is supplied to the image processing unit 61. The image processing unit 61 generates second image data that visualizes changes in the relative angle θ along the time axis.

(4) Operation of Golf Swing Analysis Device The operation of the golf swing analysis device 11 will be briefly described. First, the golf swing of the golfer G is measured. Prior to the measurement, necessary information is input from the input device 23 to the arithmetic processing circuit 16. Here, according to the three-dimensional double pendulum model 31, the masses m ₁ and m _{2 of} the first and second links 32 and 33, the inertia tensor J ₁ around the fulcrum x ₀ of the first link 32, and the second link 33 Inertia tensor J ₂ around joint x ₁ , length of first link 32 (from fulcrum x ₀ to joint x ₁ ) l ₁ , length l _g1 from fulcrum x ₀ of first link 32 to center of gravity x _g 1, 1 links 32 and joint lengths from _{x 1} to the center of gravity _{x g2 l} g2, _{l 1} of the axial unit vector _e l1, _{l 2} axial direction of the unit vector _{e l2} between the second link 33, a local coordinate system sigma _s1 position _{l s0} of the fulcrum 34 in accordance with the position _{l sj1} of joint 35 in accordance with the local coordinate system sigma _s1, rotation matrix ^{R 0} of the initial attitude of the first inertial sensor 12, as well as, the initial posture of the second inertial sensor 13 input of the rotation matrix ^{R 0} is It is. The input information is managed under a specific identifier, for example. The identifier may identify a specific golfer G.

  Prior to the measurement, the first and second inertial sensors 12 and 13 are attached to the golf club 14 and the upper limb 15 of the golfer. If the upper limb 15 is right-handed, the left arm may be selected. This is because with the left arm, the elbow is less bent from the start of the golf swing to the impact. The first and second inertial sensors 12 and 13 are fixed to the golf club 14 and the upper limb 15 so as not to be relatively displaced.

Prior to the execution of the golf swing, measurement of the first and second inertial sensors 12 and 13 is started. At the start of measurement, the first and second inertial sensors 12 and 13 are set to predetermined positions and postures. These positions and postures correspond to those specified by the rotation matrix R ⁰ of the initial posture. During the measurement, synchronization is ensured between the first and second inertial sensors 12 and 13. The first and second inertial sensors 12 and 13 continuously measure acceleration and angular velocity at specific sampling intervals. The sampling interval defines the measurement resolution. The detection signals of the first and second inertial sensors 12 and 13 may be sent to the arithmetic processing circuit 16 in real time, or may be temporarily stored in a storage device built in the inertial sensors 12 and 13. In the latter case, the detection signal may be sent to the arithmetic processing circuit 16 by wire or wireless after the end of the golf swing.

  In response to receiving the detection signal, the arithmetic processing circuit 16 performs golf swing analysis. The analysis may be performed from the start to the end of the golf swing or may be performed from the start to the impact of the golf swing. As a result, the arithmetic processing circuit 16 calculates the relative angle θ and the total energy change rate. The image data unit 62 generates first and second image data in accordance with the calculation of the relative angle θ and the total energy change rate. The first and second image data are supplied to the display processing circuit 21. As a result, a desired image is displayed on the screen of the display device 22.

  The inventor has verified the operation of the golf swing analysis apparatus 11. The lesson professional swing and amateur golfer swing were compared. The present inventor observed the relative angle θ of the lesson professional. As shown in FIG. 5, it was confirmed that the relative angle θ gradually decreased from the top to the impact in the lesson professional swing. In particular, it was confirmed that the gradient of decrease increased from the time when the relative angle θ = 100 °. On the other hand, as shown in FIG. 6, in the swing of an amateur golfer, it was confirmed that the relative angle θ = 80 ° was maintained until a certain time, and thereafter the relative angle θ rapidly decreased. When the relative angle θ between the upper limb 15 and the golf club 14 is observed in this manner, a golf swing form that can efficiently transmit energy to the golf club can be derived. Indices can be provided regarding the form of the golf swing. For example, by repeatedly changing and observing the form, good improvements can be made to the golf swing form through trial and error.

  The inventor observed lesson pro total energy change rate signals. As shown in FIG. 7, in the lesson professional swing, the zero point (zero cross in the figure) of the total energy change rate of the upper limb 15 was confirmed at a relatively early stage. As shown in FIG. 8, it was confirmed that the total energy change rate of the upper limb 15 turned from positive to negative at a relatively high position during the downswing of the golf club 14. It was confirmed that the pendulum movement of the golf club 14 started around the joint 35 at a relatively early stage of the swing. On the other hand, as shown in FIG. 9, in the swing of an amateur golfer, the zero point (zero cross in the figure) of the total energy change rate of the upper limb 15 was confirmed immediately before the impact. As shown in FIG. 10, it was confirmed that the total energy change rate of the upper limb 15 turned from positive to negative at a relatively low position during the downswing of the golf club 14. It can be predicted that the pendulum motion of the golf club 14 around the joint 35 contributes to the improvement of the transmission rate η. If a zero crossing of the total energy change rate is observed in this way, a golf swing form that can efficiently transmit energy to the golf club can be derived. Indices can be provided regarding the form of the golf swing. For example, by repeatedly changing and observing the form, good improvements can be made to the golf swing form through trial and error. In addition, as shown in FIGS. 5 and 6, better form analysis can be achieved if the zero cross timing is related to the relative angle θ of the upper limb 15 and the golf club 14.

  In the golf swing analyzing apparatus 11, a specific part of the upper body of the golfer G, that is, the upper limb 15 forms a first link 32 of the three-dimensional double pendulum model 31, and the golf club 14 is a second link of the three-dimensional double pendulum model 31. 33 is formed. Thus, the golf swing is modeled. The three-dimensional double pendulum model 31 can dynamically reproduce a golf swing with relatively high accuracy. Thus, the golf swing is effectively analyzed. In addition, the fulcrum 34 of the first link 32 is located at the center of a straight line connecting both shoulders of the golfer G. The joint 35 of the first link 32 and the second link 33 is located on the grip of the golf club 14. Thus, the golf swing is analyzed with high accuracy.

  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 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 golf swing analysis device 11, the first and second inertial sensors 12, 13, the arithmetic processing circuit 16, and the like are not limited to those described in the present embodiment, and various modifications are possible.

  DESCRIPTION OF SYMBOLS 11 Golf swing analyzer, 12 1st inertial sensor, 13 2nd inertial sensor, 14 golf club, 15 Upper body part (upper limb), 31 3D double pendulum model, 32 1st link, 33 2nd link, 34 Support point, 35 joints, 61 energy change rate inversion detection unit, 69 calculation unit (relative angle calculation unit), G golfer.

Claims (7)

A first inertial sensor attached to the upper body part of the golfer;
A second inertial sensor attached to the golf club;
A calculation unit for calculating a relative angle between the first inertial sensor and the second inertial sensor based on outputs of the first inertial sensor and the second inertial sensor;
A golf swing analyzing apparatus comprising: The golf swing analyzing apparatus according to claim 1,
A golf swing analysis apparatus, further comprising an image data generation unit that generates image data for visualizing a change in the relative angle along a time axis. In the golf swing analysis device according to claim 1 or 2,
In calculating the relative angle, a three-dimensional double pendulum model is used, the upper body part forms a first link of the three-dimensional double pendulum model, and the golf club is the three-dimensional double pendulum model. A golf swing analyzing apparatus characterized in that the second link is formed. In the golf swing analysis apparatus according to claim 3,
A golf swing analyzing apparatus characterized in that a fulcrum of the first link is located at the center of a line connecting both shoulders of the golfer, and a joint of the first link and the second link is located at a grip of the golf club. . In the golf swing analysis apparatus according to any one of claims 1 to 4,
The golf swing analysis apparatus, wherein the first inertia sensor and the second inertia sensor include an acceleration sensor having a plurality of detection axes and a gyro sensor having a plurality of detection axes. In the golf swing analysis apparatus according to any one of claims 1 to 5,
The golf swing analysis apparatus further comprising an energy change rate inversion detection unit that specifies a positive / negative balance of the total energy change rate of the part of the upper body.   A relative angle is calculated between the first inertia sensor and the second inertia sensor based on an output of a first inertia sensor attached to the upper body part of the golfer and a second inertia sensor attached to the golf club. A golf swing analysis method.

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