Patent Publication Number: US-10307656-B2

Title: Swing diagnosis apparatus, swing diagnosis system, swing diagnosis method, and recording medium

Description:
BACKGROUND 
     1. Technical Field 
     The present invention relates to a swing diagnosis apparatus, a swing diagnosis system, a swing diagnosis method, and a recording medium. 
     2. Related Art 
     JP-A-2004-135908 discloses a measurement system provided with sensor means for detecting passing of a golf club head which is swung downward in order to hit a golf ball; an impact camera which captures an image of impact; a first ball measurement camera and a second ball measurement camera which are set at positions separated from each other by a predetermined distance along a flight line (flight trajectory) of a hit ball in order to capture images of the hit ball after the impact; a performance measurement device of the golf club; and a monitor which displays a movement state of the golf ball. The measurement system analyzes a movement state of the hit golf ball on the basis of the images, and displays the movement state of the golf ball as a radar chart. Therefore, according to the measurement system, it is possible to easily evaluate performance of a golf club on the basis of a movement state of the golf ball. 
     However, the measurement system disclosed in JP-A-2004-135908 displays a movement state of the hit golf ball, that is, data after impact, as a radar chart, and thus it is hard to understand features of a swing till the impact even if the radar chart is observed. 
     SUMMARY 
     An advantage of some aspects of the invention is to provide a swing diagnosis apparatus, a swing diagnosis system, and a swing diagnosis method, and a recording medium, capable of clearly showing features of a swing till impact. 
     The invention can be implemented as the following forms or application examples. 
     APPLICATION EXAMPLE 1 
     A swing diagnosis apparatus according to this application example includes a level calculation section that calculates a level on the basis of a relationship between an incidence angle of a ball hitting portion of an exercise appliance at impact, and an inclination of the ball hitting portion of the exercise appliance at impact. 
     The exercise appliance is a tool used for a swing, and may be, for example, a golf club, a tennis racket, a baseball bat, or a hockey stick. 
     The level calculation section may calculate the level on the basis of data regarding a swing. The data regarding the swing may be, for example, measured data of acceleration or angular velocity regarding the swing, and may be analysis information including values of indexes indicating features of the swing, obtained by analyzing the measured data. Alternatively, the data regarding the swing may be data in which some or all values of indexes indicating features of the swing are pseudo-values. The data regarding the swing may be data based on an output signal from an inertial sensor measuring acceleration or angular velocity regarding the swing. According to the swing diagnosis apparatus of this application example, a level is calculated on the basis of a relationship between an incidence angle and an inclination of the ball hitting portion of the exercise appliance at impact, and thus it is possible to grade and clearly show features of the swing till the impact. 
     APPLICATION EXAMPLE 2 
     In the swing diagnosis apparatus according to the application example, the incidence angle of the ball hitting portion may be an angle formed between a direction in which the ball hitting portion passes through a ball hitting point and a target hit ball direction. 
     The incidence angle of the ball hitting portion may be an angle formed between a direction in which the ball hitting portion passes through a ball hitting point in a reference plane (for example, a horizontal plane) and a target hit ball direction in the reference plane. 
     According to the swing diagnosis apparatus of this application example, it is possible to grade and clearly show a feature of the swing based on a relationship between an incidence angle of the ball hitting portion with respect to a target hit ball direction at impact and an inclination of the ball hitting portion at impact. 
     APPLICATION EXAMPLE 3 
     In the swing diagnosis apparatus according to the application example, the inclination of the ball hitting portion may be a difference between an angle formed between an outer edge of a hitting surface of the ball hitting portion and a virtual straight line orthogonal to the target hit ball direction, and the incidence angle, in a plan view. 
     The inclination of the ball hitting portion may be an angle formed between a line of intersection of the hitting surface of the ball hitting portion and a reference plane (for example, a horizontal plane), and a virtual straight line orthogonal to a target hit ball direction in the reference plane. 
     According to the swing diagnosis apparatus of this application example, it is possible to grade and clearly show a feature of the swing based on a relationship between an incidence angle of the ball hitting portion at impact and an inclination of the ball hitting portion with respect to a target hit ball direction at impact. 
     APPLICATION EXAMPLE 4 
     In the swing diagnosis apparatus according to the application example, the level calculation section may calculate a lower level as a hit ball predicted on the basis of the relationship is more easily curved. 
     The term “easily curved” may indicate that a trajectory after ball hitting is easily curved, and may indicate that a hit ball direction is easily deviated relative to a target direction. The level calculation section may calculate a higher score as a hit ball more easily flies straight. The term “easily flies straight” may indicate that a trajectory after ball hitting is hardly curved, and may indicate that a hit ball direction is hardly deviated relative to a target direction. 
     According to the swing diagnosis apparatus of this application example, it is possible to grade and clearly show features of the swing till the impact according to the extent to which a hit ball is easily curved. 
     APPLICATION EXAMPLE 5 
     In the swing diagnosis apparatus according to the application example, the level calculation section may calculate the level on the basis of a speed of the ball hitting portion at impact. 
     The level calculation section may calculate a level on the basis of a speed of the ball hitting portion at impact separately from the level calculated on the basis of the relationship. Alternatively, the level calculation section may calculate a single level (total score) on the basis of the relationship and the speed of the ball hitting portion at impact. 
     According to the swing diagnosis apparatus of this application example, it is possible to grade and clearly show a feature of the swing based on a speed of the ball hitting portion of the exercise appliance at impact. 
     APPLICATION EXAMPLE 6 
     In the swing diagnosis apparatus according to the application example, the level calculation section may calculate a lower level as the speed becomes lower. 
     The level calculation section may calculate a higher level as the speed becomes higher. 
     According to the swing diagnosis apparatus of this application example, it is possible to grade and clearly show a feature of the swing according to a speed of the ball hitting portion at impact. 
     APPLICATION EXAMPLE 7 
     The swing diagnosis apparatus according to the application example may further include a display section that displays the level calculated by the level calculation section. 
     According to the swing diagnosis apparatus of this application example, it is possible to present information obtained by leveling features of the swing till the impact so that the information can be easily visually recognized. 
     APPLICATION EXAMPLE 8 
     In the swing diagnosis apparatus according to the application example, the level may be a score. 
     According to the swing diagnosis apparatus of this application example, it is possible to digitalize and clearly show features of the swing till the impact. 
     APPLICATION EXAMPLE 9 
     A swing diagnosis system according to this application example includes any one of the swing diagnosis apparatuses according to the application examples; and an inertial sensor, in which the level calculation section calculates a level on the basis of outputs from the inertial sensor. 
     The inertial sensor may be a sensor which can measure an inertial amount such as acceleration or angular velocity, and may be, for example, an inertial measurement unit (IMU) which can measure acceleration or angular velocity. For example, the inertial sensor may be attached to an exercise appliance or a part of a user so as to be attachable to and detachable from the exercise appliance or the user, and may be fixed to the exercise appliance so as to not be detached therefrom as a result of being built into the exercise appliance. 
     According to the swing diagnosis system of this application example, the swing diagnosis apparatus calculates a level on the basis of a relationship between an incidence angle and an inclination of the ball hitting portion of the exercise appliance at impact by using outputs from the inertial sensor, and can thus level and clearly show features of the swing till the impact. 
     APPLICATION EXAMPLE 10 
     A swing diagnosis method according to this application example includes a procedure of calculating a level on the basis of a relationship between an incidence angle of a ball hitting portion of an exercise appliance at impact, and an inclination of the ball hitting portion of the exercise appliance at impact. 
     APPLICATION EXAMPLE 11 
     A swing diagnosis program according to this application example causes a computer to execute a procedure of calculating a level on the basis of a relationship between an incidence angle of a ball hitting portion of an exercise appliance at impact, and an inclination of the ball hitting portion of the exercise appliance at impact. 
     APPLICATION EXAMPLE 12 
     A recording medium according to this application example records a swing diagnosis program causing a computer to execute a procedure of calculating a level on the basis of a relationship between an incidence angle of a ball hitting portion of an exercise appliance at impact, and an inclination of the ball hitting portion of the exercise appliance at impact. 
     According to the swing diagnosis method, the swing diagnosis program, or the recording medium of these application examples, a level is calculated on the basis of a relationship between an incidence angle and an inclination of the ball hitting portion of the exercise appliance at impact, and thus it is possible to grade and clearly show features of the swing till the impact. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements. 
         FIG. 1  is a diagram illustrating a summary of a swing diagnosis system of a first embodiment. 
         FIG. 2  is a diagram illustrating examples of a position at which and a direction in which the sensor unit is attached. 
         FIG. 3  is a diagram illustrating procedures of actions performed by a user until the user hits a ball. 
         FIG. 4  is a diagram illustrating an example of an input screen of physical information and golf club information. 
         FIG. 5  is a diagram illustrating a swing action. 
         FIG. 6  is a diagram illustrating an example of a swing diagnosis screen. 
         FIG. 7  is a diagram illustrating a configuration example of a swing diagnosis system of the first embodiment. 
         FIG. 8  is a plan view in which a golf club and the sensor unit are viewed from a negative side of an X axis during standing still of the user. 
         FIG. 9  is a graph illustrating examples of temporal changes of three-axis angular velocities. 
         FIG. 10  is a graph illustrating a temporal change of a combined value of the three-axis angular velocities. 
         FIG. 11  is a graph illustrating a temporal change of a derivative of the combined value. 
         FIG. 12  is a diagram for explaining a face angle and a club path (incidence angle). 
         FIG. 13  is a diagram illustrating an example of an impact score table. 
         FIG. 14  is a diagram illustrating an example of a speed score table. 
         FIG. 15  is a flowchart illustrating examples of procedures of a swing diagnosis process (swing diagnosis method) of the first embodiment. 
         FIG. 16  is a flowchart illustrating examples of procedures of a process of calculating scores and a total score of predetermined items. 
         FIG. 17  is a diagram illustrating a configuration example of a swing diagnosis system of a second embodiment. 
         FIG. 18  is a diagram illustrating configuration examples of a sensor unit and a swing analysis apparatus of the second embodiment. 
         FIG. 19  is a diagram illustrating a configuration example of a swing diagnosis apparatus of the second embodiment. 
         FIG. 20  is a flowchart illustrating examples of procedures of a process performed by the swing analysis apparatus in relation to a swing diagnosis process of the second embodiment. 
         FIG. 21  is a flowchart illustrating examples of procedures of the swing diagnosis process (swing diagnosis method) of the second embodiment. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Hereinafter, preferred embodiments of the invention will be described with reference to the drawings. The embodiments described below are not intended to improperly limit the content of the invention disclosed in the appended claims. In addition, all constituent elements described below are not essential constituent elements of the invention. 
     Hereinafter, a swing diagnosis system performing diagnosis of a golf swing will be described as an example. 
     1. Swing Diagnosis System 
     1-1. First Embodiment 
     1-1-1. Summary of Swing Diagnosis System 
       FIG. 1  is a diagram illustrating a summary of a swing diagnosis system of a first embodiment. A swing diagnosis system  1  of the first embodiment is configured to include a sensor unit  10  and a swing diagnosis apparatus  20 . 
     The sensor unit  10  (an example of an inertial sensor) can measure acceleration generated in each axial direction of three axes and angular velocity generated around each of the three axes, and is attached to a golf club  3 . 
     In the present embodiment, as illustrated in  FIG. 2 , the sensor unit  10  is attached to a part of a shaft so that one axis of three detection axes (an x axis, a y axis, and a z axis), for example, the y axis matches a longitudinal direction of the shaft of the golf club  3  (a longitudinal direction of the golf club  3 ). Preferably, the sensor unit  10  is attached to a position close to a grip to which impact during ball hitting is hardly forwarded and centrifugal force is hardly applied during a swing. The shaft is a shaft portion other than a head of the golf club  3  and also includes the grip. However, the sensor unit  10  may be attached to a part (for example, the hand or a glove) of a user  2 , and may be attached to an accessory such as a wristwatch. 
     The user  2  performs a swing action for hitting a golf ball  4  according to predefined procedures.  FIG. 3  is a diagram illustrating procedures of actions performed by the user  2  until the user hits the ball. As illustrated in  FIG. 3 , first, the user  2  performs an input operation of physical information of the user  2 , information (golf club information) regarding the golf club  3  used by the user  2 , and the like via the swing diagnosis apparatus  20  (step S 1 ). The physical information includes at least one of information regarding a height, a length of the arms, and a length of the legs of the user  2 , and may further include information regarding sex or other information. The golf club information includes at least one of information regarding a length (club length) of the golf club  3  and the type (number) of golf club  3 . Next, the user  2  performs a measurement starting operation (an operation for starting measurement in the sensor unit  10 ) via the swing diagnosis apparatus  20  (step S 2 ). Next, after receiving a notification (for example, a notification using a voice) of giving an instruction for taking an address attitude (a basic attitude before starting a swing) from the swing diagnosis apparatus  20  (Yin step S 3 ), the user  2  takes an address attitude so that the axis in the longitudinal direction of the shaft of the golf club  3  is perpendicular to a target line (target hit ball direction), and stands still (step S 4 ). Next, the user  2  receives a notification (for example, a notification using a voice) of permitting a swing from the swing diagnosis apparatus  20  (Y in step S 5 ), and then hits the golf ball  4  by performing a swing action (step S 6 ). 
       FIG. 4  is a diagram illustrating an example of an input screen of physical information and golf club information, displayed on a display section  25  (refer to  FIG. 7 ) of the swing diagnosis apparatus  20 . In step S 1  in  FIG. 3 , the user  2  inputs physical information such as a height, sex, age, and country, and inputs golf club information such as a club length, and a number on the input screen illustrated in  FIG. 4 . Information included in the physical information is not limited thereto, and, the physical information may include, for example, at least one of information regarding a length of the arms and a length of the legs instead of or along with the height. Similarly, information included in the golf club information is not limited thereto, and, for example, the golf club information may not include at least one of information regarding the club length and the number, and may include other information. 
     If the user  2  performs the measurement starting operation in step S 2  in  FIG. 3 , the swing diagnosis apparatus  20  transmits a measurement starting command to the sensor unit  10 , and the sensor unit  10  receives the measurement starting command and starts measurement of three-axis accelerations and three-axis angular velocities. The sensor unit  10  measures three-axis accelerations and three-axis angular velocities in a predetermined cycle (for example, 1 ms), and sequentially transmits the measured data to the swing diagnosis apparatus  20 . Communication between the sensor unit  10  and the swing diagnosis apparatus  20  may be wireless communication, and may be wired communication. 
     The swing diagnosis apparatus  20  notifies the user  2  of permission of swing starting, shown in step S 5  in  FIG. 3 , and then analyzes the swing action (step S 6  in  FIG. 3 ) in which the user  2  has hit the ball by using the golf club  3  on the basis of measured data (an example of an output from an inertial sensor) from the sensor unit  10 . 
     As illustrated in  FIG. 5 , the swing action performed by the user  2  in step S 6  in  FIG. 3  includes an action reaching impact (ball hitting) at which the golf ball  4  is hit through respective states of halfway back at which the shaft of the golf club  3  becomes horizontal during a backswing after starting a swing (backswing), a top at which the swing changes from the backswing to a downswing, and halfway down at which the shaft of the golf club  3  becomes horizontal during the downswing. The swing diagnosis apparatus  20  generates swing analysis data including information regarding a time point (date and time) at which the swing is performed, identification information or the sex of the user  2 , the type of golf club  3 , and an analysis result of the swing action. 
     The swing diagnosis apparatus  20  calculates levels of predetermined items indicating features of a swing of the user  2  by using the swing analysis data generated on the basis of the measured data in the sensor unit  10 . Specifically, the swing diagnosis apparatus  20  calculates levels of respective two items such as an “impact” item and a “speed” item, for example, as 5 points maximum. Meanings or a calculation method of the two items will be described later. The swing diagnosis apparatus  20  may calculate a total score of the swing by using the levels of the two items. The “levels” may be represented by, for example, “1, 2, 3, . . . ”, “A, B, C, . . . ”, “O, X, Δ, . . . ”, and may be represented by scores. 
     The swing diagnosis apparatus  20  displays, for example, a swing diagnosis screen as illustrated in  FIG. 6  on the display section  25  by using information regarding the calculated levels and total score of the predetermined items. The swing diagnosis screen illustrated in  FIG. 6  includes information regarding the swing analysis data on a left part thereof. The information regarding the swing analysis data is data information used for diagnosis of the swing (that is, calculation of the levels and the total score of the two items) in the swing diagnosis apparatus  20 . The information regarding the swing analysis data includes values obtained on the basis of the swing analysis data with respect to sex, the type of golf club (a driver or an iron), and respective indexes of the swing. Meanings or a calculation method of the respective indexes (a face angle, a club path (incidence angle), and a head speed) will be described later. The swing diagnosis screen illustrated in  FIG. 6  includes information regarding scores as the levels of the two items and the total score on a right part thereof. 
     The user  2  can understand levels and a total score of predetermined items as diagnosis results for the swing analysis data on the left part on the basis of the swing diagnosis screen illustrated in  FIG. 6 . Particularly, if the user  2  can understand strong points or weak points in the user&#39;s swing on the basis of the swing diagnosis screen illustrated in  FIG. 6 . Hereinafter, a description will be made of an example in which “levels” of predetermined items are represented by “scores”, but, needless to say, the example can be easily replaced with an example of the levels being expressed by “1, 2, 3, . . . ”, “A, B, C, . . . ”, “O, X, Δ”, or the like. 
     For example, the swing diagnosis apparatus  20  may be implemented by an information terminal (client terminal) such as a smart phone or a personal computer. 
     1-1-2. Configuration of Sensor Unit and Swing Diagnosis Apparatus 
       FIG. 7  is a diagram illustrating configuration examples (configuration examples of the sensor unit  10  and the swing diagnosis apparatus  20 ) of the swing diagnosis system  1  of the first embodiment. As illustrated in  FIG. 7 , in the present embodiment, the sensor unit  10  is configured to include an acceleration sensor  12 , an angular velocity sensor  14 , a signal processing section  16 , and a communication section  18 . However, the sensor unit  10  may have a configuration in which some of the constituent elements are deleted or changed as appropriate, or may have a configuration in which other constituent elements are added thereto. 
     The acceleration sensor  12  measures respective accelerations generated in three axial directions which intersect (ideally, orthogonal to) each other, and outputs digital signals (acceleration data) corresponding to magnitudes and directions of the measured three-axis accelerations. 
     The angular velocity sensor  14  measures respective angular velocities generated around each of the three axes which intersect (ideally, orthogonal to) each other, and outputs digital signals (angular velocity data) corresponding to magnitudes and directions of the measured three-axis angular velocities. 
     The signal processing section  16  receives the acceleration data and the angular velocity data from the acceleration sensor  12  and the angular velocity sensor  14 , respectively, adds time information thereto, stores the data in a storage portion (not illustrated), adds time information to the stored measured data (acceleration data and angular velocity data) so as to generate packet data conforming to a communication format, and outputs the packet data to the communication section  18 . 
     Ideally, the acceleration sensor  12  and the angular velocity sensor  14  are provided in the sensor unit  10  so that the three axes thereof match three axes (an x axis, a y axis, and a z axis) of an orthogonal coordinate system (sensor coordinate system) defined for the sensor unit  10 , but, actually, errors occur in installation angles. Therefore, the signal processing section  16  performs a process of converting the acceleration data and the angular velocity data into data in the xyz coordinate system by using a correction parameter which is calculated in advance according to the installation angle errors. 
     The signal processing section  16  may perform a process of correcting the temperatures of the acceleration sensor  12  and the angular velocity sensor  14 . The acceleration sensor  12  and the angular velocity sensor  14  may have a temperature correction function. 
     The acceleration sensor  12  and the angular velocity sensor  14  may output analog signals, and, in this case, the signal processing section  16  may A/D convert an output signal from the acceleration sensor  12  and an output signal from the angular velocity sensor  14  so as to generate measured data (acceleration data and angular velocity data), and may generate communication packet data by using the data. 
     The communication section  18  performs a process of transmitting packet data received from the signal processing section  16  to the swing diagnosis apparatus  20 , or a process of receiving various control commands such as measurement starting command from the swing diagnosis apparatus  20  and sending the control command to the signal processing section  16 . The signal processing section  16  performs various processes corresponding to control commands. 
     As illustrated in  FIG. 7 , in the present embodiment, the swing diagnosis apparatus  20  is configured to include a processing section  21 , a communication section  22 , an operation section  23 , a storage section  24 , the display section  25 , and a sound output section  26 . However, the swing diagnosis apparatus  20  may have a configuration in which some of the constituent elements are deleted or changed as appropriate, or may have a configuration in which other constituent elements are added thereto. 
     The communication section  22  performs a process of receiving packet data transmitted from the sensor unit  10  and sending the packet data to the processing section  21 , or a process of transmitting a control command from the processing section  21  to the sensor unit  10 . 
     The operation section  23  performs a process of acquiring operation data from the user  2  and sending the operation data to the processing section  21 . The operation section  23  may be, for example, a touch panel type display, a button, a key, or a microphone. 
     The storage section  24  is constituted of, for example, various IC memories such as a read only memory (ROM), a flash ROM, and a random access memory (RAM), or a recording medium such as a hard disk or a memory card. The storage section  24  stores a program for the processing section  21  performing various calculation processes or a control process, or various programs or data for realizing application functions. 
     In the present embodiment, the storage section  24  stores a swing diagnosis program  240  which is read by the processing section  21  and executes a swing diagnosis process. The swing diagnosis program  240  may be stored in a nonvolatile recording medium (computer readable recording medium) in advance, or the swing diagnosis program  240  may be received from a server (not illustrated) by the processing section  21  via a network, and may be stored in the storage section  24 . 
     In the present embodiment, the storage section  24  stores golf club information  241 , physical information  242 , sensor attachment position information  243 , and swing analysis data  244 . For example, the user  2  may operate the operation section  23  so as to input specification information regarding the golf club  3  to use (for example, at least some information such as information regarding a length of the shaft, a position of the centroid thereof, a lie angle, a face angle, a loft angle, and the like) from the input screen illustrated in  FIG. 4 , and the input specification information may be used as the golf club information  241 . Alternatively, in step S 1  in  FIG. 3 , the user  2  may sequentially input type numbers of the golf club  3  (alternatively, selects a type number from a type number list) so that specification information for each type number is stored in the storage section  24  in advance. In this case, specification information of an input type number may be used as the golf club information  241 . 
     For example, the user  2  may input physical information by operating the operation section  23  from the input screen illustrated in  FIG. 4 , and the input physical information may be used as the physical information  242 . For example, in step S 1  in  FIG. 3 , the user  2  may input a distance between an attachment position of the sensor unit  10  and the grip end of the golf club  3  by operating the operation section  23 , and the input distance information may be used as the sensor attachment position information  243 . Alternatively, the sensor unit  10  may be attached at a defined predetermined position (for example, a distance of 20 cm from the grip end), and thus information regarding the predetermined position may be stored as the sensor attachment position information  243  in advance. 
     The swing analysis data  244  is data including information regarding a swing action analysis result in the processing section  21  (swing analysis portion  211 ) along with a time point (date and time) at which a swing was performed, identification information or the sex of the user  2 , and the type of golf club  3 . 
     The storage section  24  stores an impact score table  245  and a speed score table  246 . The score tables will be described later in detail. 
     The storage section  24  is used as a work area of the processing section  21 , and temporarily stores data which is input from the operation section  23 , results of calculation executed by the processing section  21  according to various programs, and the like. The storage section  24  may store data which is required to be preserved for a long period of time among data items generated through processing of the processing section  21 . 
     The display section  25  displays a processing result in the processing section  21  as text, a graph, a table, animation, and other images. The display section  25  may be, for example, a CRT, an LCD, a touch panel type display, and a head mounted display (HMD). A single touch panel type display may realize functions of the operation section  23  and the display section  25 . 
     The sound output section  26  outputs a processing result in the processing section  21  as a sound such as a voice or a buzzer sound. The sound output section  26  may be, for example, a speaker or a buzzer. 
     The processing section  21  performs a process of transmitting a control command to the sensor unit  10  via the communication section  22 , or various computation processes on data which is received from the sensor unit  10  via the communication section  22 , according to various programs. The processing section  21  performs a process of reading the swing analysis data  244  from the storage section  24 , so as to calculate scores or a total score of predetermined items and to display the swing diagnosis screen ( FIG. 6 ), according to various programs. The processing section  21  performs other various control processes. 
     Particularly, in the present embodiment, by executing the swing diagnosis program  240 , the processing section  21  functions as a data acquisition portion  210 , a swing analysis portion  211 , a score calculation portion  212 , an image data generation portion  213 , a storage processing portion  214 , a display processing portion  215 , and a sound output processing portion  216 , and performs a process (swing diagnosis process) of diagnosing a swing action of the user  2 . In the present embodiment, the swing diagnosis process includes a process (swing analysis process) of analyzing the swing action of the user  2  and a process (score calculation process) of calculating a score of the swing action. 
     The data acquisition portion  210  performs a process of receiving packet data which is received from the sensor unit  10  by the communication section  22 , acquiring time information and measured data from the received packet data, and sending the time information and the measured data to the storage processing portion  214 . 
     The storage processing portion  214  performs read/write processes of various programs or various data for the storage section  24 . The storage processing portion  214  performs not only the process of storing the time information and the measured data received from the data acquisition portion  210  in the storage section  24  in correlation with each other, but also a process of storing various pieces of information calculated by the swing analysis portion  211 , the swing analysis data  244 , or the like in the storage section  24 . For example, the storage processing portion  214  performs a process of reading the swing analysis data  244 , the impact score table  245 , and the speed score table  246  stored in the storage section  24 , and transmitting the data and the tables to the score calculation portion  212 . 
     The swing analysis portion  211  performs a process of analyzing a swing action of the user  2  by using the measured data (the measured data stored in the storage section  24 ) output from the sensor unit  10 , the data from the operation section  23 , or the like, so as to generate the swing analysis data  244  including a time point (date and time) at which the swing was performed, identification information or the sex of the user  2 , the type of golf club  3 , and information regarding a swing action analysis result. Particularly, in the present embodiment, the swing analysis portion  211  analyzing a swing action may calculates an index based on an incidence angle of the head of the golf club  3  at impact (at ball hitting) as an index of the swing. For example, the swing analysis portion  211  may calculates a club path (incidence angle) ψ which will be described later as the index. 
     The swing analysis portion  211  may calculate an index based on an inclination of the head of the golf club  3  at impact (at ball hitting) as an index of the swing. For example, the swing analysis portion  211  may calculates a “(absolute) face angle ϕ” or “relative face angle η” which will be described later as the index. 
     The swing analysis portion  211  may calculate an index based on a speed the golf club  3  at impact (at ball hitting) as an index of the swing. For example, the swing analysis portion  211  may calculate a “head speed” as the index. 
     However, the swing analysis portion  211  may not calculate values of some of the indexes, and may calculate values of other indexes, as appropriate. 
     The score calculation portion  212  (level calculation section) performs a process of calculating scores (levels) of predetermined items indicating features of the swing of the user  2  on the basis of data regarding the swing. In the present embodiment, the data regarding the swing is the swing analysis data  244 . 
     The score calculation portion  212  performs a process of calculating a total score on the basis of the scores of the predetermined items. The score calculation portion  212  performs a process of transmitting information regarding the calculated scores and total score of the predetermined items to the image data generation portion  213 . 
     The image data generation portion  213  performs a process of generating image data corresponding to an image displayed on the display section  25 . For example, the image data generation portion  213  generates image data corresponding to the swing diagnosis screen illustrated in  FIG. 6  on the basis of the information regarding the calculated scores and total score of the predetermined items received from the score calculation portion  212 . 
     The display processing portion  215  performs a process of displaying various images (including text, symbols, and the like in addition to an image corresponding to the image data generated by the image data generation portion  213 ) on the display section  25 . For example, the display processing portion  215  displays the swing diagnosis screen illustrated in  FIG. 6 , and the like, on the display section  25 , on the basis of the image data generated by the image data generation portion  213 . For example, the image data generation portion  213  may display an image, text, or the like for notifying the user  2  of permission of swing starting on the display section  25  in step S 5  in  FIG. 3 . For example, the display processing portion  215  may display text information such as text or symbols indicating an analysis result in the swing analysis portion  211  on the display section  25  automatically or in response to an input operation performed by the user  2  after a swing action of the user  2  is completed. Alternatively, a display section may be provided in the sensor unit  10 , and the display processing portion  215  may transmit image data to the sensor unit  10  via the communication section  22 , and various images, text, or the like may be displayed on the display section of the sensor unit  10 . 
     The sound output processing portion  216  performs a process of outputting various sounds (including voices, buzzer sounds, and the like) from the sound output section  26 . For example, the sound output processing portion  216  may output a sound for notifying the user  2  of permission of swing starting from the sound output section  26  in step S 5  in  FIG. 3 . For example, the sound output processing portion  216  may output a sound or a voice indicating an analysis result in the swing analysis portion  211  from the sound output section  26  automatically or in response to an input operation performed by the user  2  after a swing action of the user  2  is completed. Alternatively, a sound output section may be provided in the sensor unit  10 , and the sound output processing portion  216  may transmit various items of sound data or voice data to the sensor unit  10  via the communication section  22 , and may output various sounds or voices from the sound output section of the sensor unit  10 . 
     A vibration mechanism may be provided in the swing diagnosis apparatus  20  or the sensor unit  10 , and various pieces of information may be converted into vibration pieces of information by the vibration mechanism so as to be presented to the user  2 . 
     1-1-3. Swing Analysis Process 
     In the present embodiment, when a position of the head of the golf club  3  at address (during standing still) is set to the origin, an XYZ coordinate system (global coordinate system) is defined which has a target line indicating a target hit ball direction as an X axis, an axis on a horizontal plane which is perpendicular to the X axis as a Y axis, and a vertically upward direction (a direction opposite to the gravitational acceleration direction) as a Z axis. In order to calculate each index value, the swing analysis portion  211  calculates a position and an attitude of the sensor unit  10  in a time series from the time of the address in the XYZ coordinate system (global coordinate system) by using measured data (acceleration data and angular velocity data) in the sensor unit  10 . The swing analysis portion  211  detects respective timings of the swing starting, the top, and the impact illustrated in  FIG. 5 , by using the measured data (acceleration data or angular velocity data) in the sensor unit  10 . The swing analysis portion  211  calculates values of the respective indexes (for example, a face angle ϕ, a relative face angle η, a club path (incidence angle) ψ, and a head speed) of the swing by using the time series data of the position and the attitude of the sensor unit  10 , and the timings of the swing starting, the top, and the impact, so as to generate the swing analysis data  244 . 
     Calculation of Position and Attitude of Sensor Unit  10   
     If the user  2  performs the action in step S 4  in  FIG. 3 , first, the swing analysis portion  211  determines that the user  2  stands still at an address attitude in a case where an amount of changes in acceleration data measured by the acceleration sensor  12  does not continuously exceed a threshold value for a predetermined period of time. Next, the swing analysis portion  211  computes an offset amount included in the measured data by using the measured data (acceleration data and angular velocity data) for the predetermined period of time. Next, the swing analysis portion  211  subtracts the offset amount from the measured data so as to perform bias correction, and computes a position and an attitude of the sensor unit  10  during a swing action of the user  2  (during the action in step S 6  in  FIG. 3 ) by using the bias-corrected measured data. 
     Specifically, first, the swing analysis portion  211  computes a position (initial position) of the sensor unit  10  during standing still (at address) of the user  2  in the XYZ coordinate system (global coordinate system) by using the acceleration data measured by the acceleration sensor  12 , the golf club information  241 , and the sensor attachment position information  243 . 
       FIG. 8  is a plan view in which the golf club  3  and the sensor unit  10  during standing still (at address) of the user  2  are viewed from a negative side of the X axis. The origin O (0,0,0) is set at a position  61  of the head of the golf club  3 , and coordinates of a position  62  of a grip end are (0, G Y , G Z ). Since the user  2  performs the action in step S 4  in  FIG. 3 , the position  62  of the grip end or the initial position of the sensor unit  10  has an X coordinate of 0, and is present on a YZ plane. As illustrated in  FIG. 8 , the gravitational acceleration of 1G is applied to the sensor unit  10  during standing still of the user  2 , and thus a relationship between a y axis acceleration y(0) measured by the sensor unit  10  and an inclined angle (an angle formed between the longitudinal direction of the shaft and the horizontal plane (XY plane)) α of the shaft of the golf club  3  is expressed by Equation (1).
 
 y (0)=1 G ·sin α  (1)
 
     Therefore, the swing analysis portion  211  can calculate the inclined angle α according to Equation (1) by using any acceleration data between any time points at address (during standing still). 
     Next, the swing analysis portion  211  subtracts a distance L SG  between the sensor unit  10  and the grip end included in the sensor attachment position information  243  from a length L 1  of the shaft included in the golf club information  241 , so as to obtain a distance L SH  between the sensor unit  10  and the head. The swing analysis portion  211  sets, as the initial position of the sensor unit  10 , a position separated by the distance L SH  from the position  61  (origin O) of the head in a direction (a negative direction of the y axis of the sensor unit  10 ) specified by the inclined angle α of the shaft. 
     The swing analysis portion  211  integrates subsequent acceleration data so as to compute coordinates of a position from the initial position of the sensor unit  10  in a time series. 
     The swing analysis portion  211  computes an attitude (initial attitude) of the sensor unit  10  during standing still (at address) of the user  2  in the XYZ coordinate system (global coordinate system) by using acceleration data measured by the acceleration sensor  12 . Since the user  2  performs the action in step S 4  in  FIG. 3 , the x axis of the sensor unit  10  matches the X axis of the XYZ coordinate system in terms of direction at address (during standing still) of the user  2 , and the y axis of the sensor unit  10  is present on the YZ plane. Therefore, the swing analysis portion  211  can specify the initial attitude of the sensor unit  10  on the basis of the inclined angle α of the shaft of the golf club  3 . 
     The swing analysis portion  211  computes changes in attitudes from the initial attitude of the sensor unit  10  in time series by performing rotation calculation using angular velocity data which is subsequently measured by the angular velocity sensor  14 . An attitude of the sensor unit  10  may be expressed by, for example, rotation angles (a roll angle, a pitch angle, and a yaw angle) about the X axis, the Y axis, and the Z axis, or a quaternion. 
     The signal processing section  16  of the sensor unit  10  may compute an offset amount of measured data so as to perform bias correction on the measured data, and the acceleration sensor  12  and the angular velocity sensor  14  may have a bias correction function. In this case, it is not necessary for the swing analysis portion  211  to perform bias correction on the measured data. 
     Detection of Swing Starting, Top and Impact Timings 
     First, the swing analysis portion  211  detects a timing (impact timing) at which the user  2  hits a ball by using measured data. For example, the swing analysis portion  211  may compute a combined value of measured data (acceleration data or angular velocity data), and may detect an impact timing (time point) on the basis of the combined value. 
     Specifically, first, the swing analysis portion  211  computes a combined value n 0  (t) of angular velocities at each time point t by using the angular velocity data (bias-corrected angular velocity data for each time point t). For example, if the angular velocity data items at the time point t are respectively indicated by x(t), y(t), and z(t), the swing analysis portion  211  computes the combined value n 0  (t) of the angular velocities according to the following Equation (2).
 
 n   0 ( t )=√{square root over ( x ( t ) 2   +y ( t ) 2   +z ( t ) 2 )}  (2)
 
     Next, the swing analysis portion  211  converts the combined value n 0  (t) of the angular velocities at each time point t into a combined value n(t) which is normalized (scale-conversion) within a predetermined range. For example, if the maximum value of the combined value of the angular velocities in an acquisition period of measured data is max (n 0 ), the swing analysis portion  211  converts the combined value n 0  (t) of the angular velocities into the combined value n(t) which is normalized within a range of 0 to 100 according to the following Equation (3). 
     
       
         
           
             
               
                 
                   
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                       100 
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                           n 
                           0 
                         
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                           ( 
                           t 
                           ) 
                         
                       
                     
                     
                       max 
                       ⁡ 
                       
                         ( 
                         
                           n 
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     Next, the swing analysis portion  211  computes a derivative dn(t) of the normalized combined value n(t) at each time point t. For example, if a cycle for measuring three-axis angular velocity data items is indicated by Δt, the swing analysis portion  211  computes the derivative (difference) dn(t) of the combined value of the angular velocities at the time point t by using the following Equation (4).
 
 dn ( t )= n ( t )− n ( t−Δt )  (4)
 
       FIG. 9  illustrates examples of three-axis angular velocity data items x(t), y(t) and z(t) obtained when the user  2  hits the golf ball  4  by performing a swing. In  FIG. 9 , a transverse axis expresses time (msec), and a longitudinal axis expresses angular velocity (dps). 
       FIG. 10  is a diagram in which the combined value n 0  (t) of the three-axis angular velocities is computed according to Equation (2) by using the three-axis angular velocity data items x(t), y(t) and z(t) in  FIG. 9 , and then the combined value n(t) normalized to 0 to 100 according to Equation (3) is displayed in a graph. In  FIG. 10 , a transverse axis expresses time (msec), and a longitudinal axis expresses a combined value of the angular velocity. 
       FIG. 11  is a diagram in which the derivative dn(t) is calculated according to Equation (4) on the basis of the combined value n(t) of the three-axis angular velocities in  FIG. 10 , and is displayed in a graph. In  FIG. 11 , a transverse axis expresses time (msec), and a longitudinal axis expresses a derivative value of the combined value of the three-axis angular velocities. In  FIGS. 9 and 10 , the transverse axis is displayed at 0 seconds to 5 seconds, but, in  FIG. 11 , the transverse axis is display at 2 seconds to 2.8 seconds so that changes in the derivative value before and after impact can be understood. 
     Next, of time points at which a value of the derivative dn(t) of the combined value becomes the maximum and the minimum, the swing analysis portion  211  specifies the earlier time point as an impact time point t impact  (impact timing) (refer to  FIG. 11 ). It is considered that a swing speed is the maximum at the moment of impact in a typical golf swing. In addition, since it is considered that a value of the combined value of the angular velocities also changes according to swing speed, the swing analysis portion  211  can capture a timing at which a derivative value of the combined value of the angular velocities is the maximum or the minimum (that is, a timing at which the derivative value of the combined value of the angular velocities is a positive maximum value or a negative minimum value) in a series of swing actions as the impact timing. Since the golf club  3  vibrates due to the impact, a timing at which a derivative value of the combined value of the angular velocities is the maximum and a timing at which a derivative value of the combined value of the angular velocities is the minimum may occur in pairs, and, of the two timings, the earlier timing may be the moment of the impact. 
     Next, the swing analysis portion  211  specifies a time point of a minimum point at which the combined value n (t) is close to 0 before the impact time point t impact , as a top time point t top  (top timing) (refer to  FIG. 10 ). It is considered that, in a typical golf swing, an action temporarily stops at the top after starting the swing, then a swing speed increases, and finally impact occurs. Therefore, the swing analysis portion  211  can capture a timing at which the combined value of the angular velocities is close to 0 and becomes the minimum before the impact timing, as the top timing. 
     Next, the swing analysis portion  211  sets an interval in which the combined value n(t) is equal to or smaller than a predetermined threshold value before and after the top time point t top , as a top interval, and detects a last time point at which the combined value n(t) is equal to or smaller than the predetermined threshold value before a starting time point of the top interval, as a swing starting (backswing starting) time point t start  (refer to  FIG. 10 ). It is hardly considered that, in a typical golf swing, a swing action is started from a standing still state, and the swing action is stopped till the top. Therefore, the swing analysis portion  211  can capture the last timing at which the combined value of the angular velocities is equal to or smaller than the predetermined threshold value before the top interval as a timing of starting the swing action. The swing analysis portion  211  may detect a time point of the minimum point at which the combined value n(t) is close to 0 before the top time point t top  as the swing starting time point t start . 
     The swing analysis portion  211  may also detect each of a swing starting timing, a top timing, an impact timing by using three-axis acceleration data in the same manner. 
     Calculation of Face Angle and Club Path (Incidence Angle) 
     The face angle is an index based on an inclination of the head of the golf club  3  at impact, and the club path (incidence angle) is an index based on a trajectory of the head of the golf club  3  at impact. 
       FIG. 12  is a diagram for explaining the face angle and the club path (incidence angle).  FIG. 12  illustrates the golf club  3  (only the head is illustrated) on the XY plane viewed from a positive side (an upper side of the user  2 ) of the Z axis in the XYZ coordinate system. In  FIG. 12 , the reference numeral  74  indicates a face surface (hitting surface) of the head of the golf club  3 , and the reference numeral  75  indicates a ball hitting point. The reference numeral  70  indicates a target line indicating a target hit ball direction, and the reference numeral  71  indicates a plane orthogonal to the target line  70 . The reference numeral  76  indicates a curve indicating a trajectory of the head of the golf club  3 , and the reference numeral  72  is a tangential line at the ball hitting point  75  for the curve  76 . In this case, the face angle ϕ is an angle formed between an outer edge (an outer edge on the ground side) of the face surface  74  and a virtual line (a line of intersection of the plane  71  and the XY plane) orthogonal to the target line  70  in a plan view (on the XY plane), that is, an angle formed between the straight line  73  orthogonal to the outer edge (the outer edge on the ground side) of the face surface  74 , and the target line  70 . The club path (incidence angle) ψ is an angle formed between the tangential line  72  (a direction in which the head in the XY plane passes through the ball hitting point  75 ) and the target line  70 . 
     For example, assuming that an angle formed between the face surface of the head and the x axis direction is normally constant (for example, orthogonal to each other), the swing analysis portion  211  computes a direction of a straight line orthogonal to the face surface on the basis of the attitude of the sensor unit  10  at the impact time point t impact . The swing analysis portion  211  uses, a straight line obtained by setting a Z axis component of the direction of the straight line to 0, as a direction of the straight line  73 , and computes an angle (face angle) ϕ formed between the straight line  73  and the target line  70 . 
     For example, the swing analysis portion  211  uses a direction of a speed (that is, a speed of the head in the XY plane) obtained by setting a Z axis component of a speed of the head at the impact time point t impact  to 0, as a direction of the tangential line  72 , and computes an angle (club path (incidence angle)) ψ formed between the tangential line  72  and the target line  70 . 
     The face angle ϕ indicates an inclination of the face surface  74  with the target line  70  whose direction is fixed regardless of an incidence direction of the head to the ball hitting point  75  as a reference, and is thus also referred to as an absolute face angle. In contrast, an angle η formed between the straight line  73  and the tangential line  72  indicates an inclination of the face surface  74  with an incidence direction of the head to the ball hitting point  75  as a reference, and is thus referred to as a relative face angle. The relative face angle η is an angle obtained by subtracting the club path (incidence angle) ψ from the (absolute) face angle ϕ. 
     Calculation of Head Speed 
     A head speed is the magnitude of a speed of the head at impact (the moment of the impact, right before the impact, or right after the impact). For example, the swing analysis portion  211  computes a speed of the head at the impact time point t impact  on the basis of differences between the coordinates of the position of the head at the impact time point t impact  and coordinates of a position of the head at the previous time point. The swing analysis portion  211  computes the magnitude of the speed of the head as the head speed. 
     1-1-4. Score Calculation Process 
     In the present embodiment, the processing section  21  (particularly, the score calculation portion  212 ) of the swing diagnosis apparatus  20  performs a process of calculating scores and a total score of predetermined items indicating features of a swing. 
     The predetermined items which are score calculation targets in the score calculation portion  212  may include an item indicating a relationship between an incidence angle of the head (an example of a ball hitting portion) of the golf club  3  (an example of an exercise appliance) at impact, and an inclination of the head of the golf club  3  at impact. 
     The incidence angle of the head may be an angle formed, in a plan view (on the XY plane), between a direction in which the head passes through a ball hitting point and a target hit ball direction (target line), that is, may be a club path (incidence angle) ψ. The inclination of the head may be a difference between an angle (that is, the (absolute) face angle ϕ) formed between the outer edge (the outer edge on the ground surface side) of the face surface (an example of a hitting surface) of the head and a virtual straight line orthogonal to a target hit ball direction (target line), and an incidence angle (that is, the club path (incidence angle) ψ) of the head, that is, may be a relative face angle η. 
     Hereinafter, the predetermined items are assumed to include an item (hereinafter, this item will be referred to as an “impact” item) indicating a relationship between the “club path (incidence angle) ψ” which is an index based on an incidence angle of the head of the golf club  3  at impact and the “relative face angle η” which is an index based on an inclination of the head at impact. 
     The predetermined items may include an item regarding a speed of the golf club  3  at impact (at ball hitting). Hereinafter, the predetermined items are assumed to include an item (hereinafter, this item will be referred to as a “speed” item) indicating a relationship among a “head speed” which is an index based on the speed of the golf club  3  at impact, “sex”, and the “type of golf club  3 ”. 
     A detailed description will be made of a method of calculating a score of each item and a method of calculating a total score in the score calculation portion  212  of the processing section  21 . 
     Calculation of Score of “Impact” Item 
     The score calculation portion  212  calculates a score of the “impact” item depending on in which range among a plurality of ranges each of the club path (incidence angle) ψ and the relative face angle η is included. Specifically, first, the score calculation portion  212  determines in which range the club path (incidence angle) ψ included in data (selected swing analysis data  244 ) regarding a swing is included. The score calculation portion  212  calculates the relative face angle η by subtracting the club path (incidence angle) ψ from the face angle ϕ included in the data (selected swing analysis data  244 ) regarding the swing (refer to  FIG. 17 ), and determines in which range the relative face angle η is included. Next, the score calculation portion  212  calculates a score corresponding to a determination result by referring to the impact score table  245 . 
     In the present embodiment, as illustrated in  FIG. 13 , the impact score table  245  defines a score for each combination of a range in which the relative face angle η is included and a range in which the club path (incidence angle) ψ is included. In the example illustrated in  FIG. 13 , a range in which the relative face angle η is included is classified into five ranges such as “η 1  or more”, “less than η 1  and η 2  or more”, “less than η 2  and η 3  or more”, “less than η 3  and η 4  or more”, and “less than η 4 ”. A range in which the club path (incidence angle) ψ is included is classified into five ranges such as “less than ψ 1 ”, “ψ 1  or more and less than ψ 2 ”, “ψ 2  or more and less than ψ 3 ”, “ψ 3  or more and less than ψ 4 ”, and “ψ 4  or more”. For example, in a case where the relative face angle η is included in the range of “η 1  or more”, and the club path (incidence angle) ψ is included in the range of “less than ψ 1 ”, a score is pi 1 . Each of scores pi 1  to pi 25  illustrated in  FIG. 13  is any one of, for example, 1 point to 5 points. 
     The score calculation portion  212  may calculate a lower score as a hit ball predicted on the basis of the club path (incidence angle) ψ and the relative face angle η becomes more easily curved. The term “easily curved” may indicate that a trajectory after ball hitting is easily curved (easily sliced or hooked), and may indicate that a hit ball direction is easily deviated relative to a target direction (target line). Alternatively, the score calculation portion  212  may calculate a higher score as a hit ball more easily flies straight. The term “easily flies straight” may indicate that a trajectory after ball hitting is hardly curved (easily straightened), and may indicate that a hit ball direction is hardly deviated relative to a target direction (target line). 
     For example, a state in which the relative face angle η is extremely large is a state in which the face surface at impact is open, and a state in which the face angle ϕ is extremely small (a negative state in which an absolute value thereof is great) is a state in which the face surface at impact is considerably closed. In either state, it is expected that a hit ball is easily curved. For example, in a state in which the club path (incidence angle) ψ is extremely large, a trajectory of the head at impact becomes considerably an inside-out trajectory, it is expected that a hit ball is easily curved. In a state in which the club path (incidence angle) ψ is extremely small (a negative state in which an absolute value thereof is great), a trajectory of the head at impact becomes considerably an outside-in trajectory, it is expected that a hit ball is easily curved. In other words, for example, in a case where the relative face angle η is included in the range of “η 1  or more” or “less than η 4 ”, and the club path (incidence angle) ψ is included in the range of “less than ψ 1 ” or “ψ 4  or more”, it is expected that a hit ball is easily curved, and thus the score calculation portion  212  calculates a relatively low score. Therefore, in the example illustrated in  FIG. 13 , pi 1 , pi 5 , pi 21 , and pi 25  may be 1 point which is the lowest score, for example, among 1 point to 5 points. 
     For example, in a case where the relative face angle η is close to 0°, and the club path (incidence angle) ψ is close to 0°, the face surface at impact is close to the square, and a trajectory of the head at impact is nearly straight. Therefore, it is expected that a hit ball easily flies straight. In other words, in a case where the relative face angle η is included in the range of “less than η 2  and η 3  or more”, and the club path (incidence angle) ψ is included in the range of “ψ 2  or more and less than ψ 3 ”, it is expected that a hit ball easily flies straight, and thus the score calculation portion  212  calculates a relatively high score (for example, 5 points maximum). Therefore, in the example illustrated in  FIG. 13 , pi 13  may be 5 points which is the highest score, for example, among 1 point to 5 points. 
     Calculation of Score of “Speed” Item 
     The score calculation portion  212  calculates a score of the “speed” item depending on in which range among a plurality of ranges a head speed is included. However, a head speed differs depending on males and females, and, generally, there is a tendency that a head speed of the males is high. A head speed differs depending on a driver or an iron, and, generally, there is a tendency that a head speed of the driver is high. Thus, it is preferable to select of a plurality of set ranges for classifying a head speed on the basis of sex or the type of golf club. Specifically, first, the score calculation portion  212  determines whether the user  2  is a male or a female, and whether the golf club  3  which is used is a driver or an iron, on the basis of information regarding the sex of the user  2  and information regarding the type of golf club  3  included in data (selected swing analysis data  244  or the like) regarding a swing. Then, the score calculation portion  212  selects a plurality of set ranges for classifying a head speed on the basis of a determination result. Next, the score calculation portion  212  determines in which range among a plurality of ranges a head speed included in the swing analysis data  244  is included. Next, the score calculation portion  212  calculates a score corresponding to a determination result by referring to the speed score table  246 . The score calculation portion  212  may calculate a lower score as a head speed becomes lower. 
     In the present embodiment, as illustrated in FIG.  14 , the speed score table  246  defines a plurality of ranges which are set depending on a “male” or a “female”, and a “driver” or an “iron”, and a score of a range in which a head speed is included for each of the plurality of set ranges. In the example illustrated in  FIG. 14 , in a case of a “male” and a “driver”, a range in which a head speed is included is classified into five ranges such as “less than vh 1 ”, “vh 1  or more and less than vh 2 ”, “vh 2  or more and less than vh 3 ”, “vh 3  or more and less than vh 4 ”, and “vh 4  or more”. In a case of a “male” and an “iron”, a range in which a head speed is included is classified into five ranges such as “less than vh 5 ”, “vh 5  or more and less than vh 6 ”, “vh 6  or more and less than vh 7 ”, “vh 7  or more and less than vh 8 ”, and “vh 8  or more”. In a case of a “female” and a “driver”, a range in which a head speed is included is classified into five ranges such as “less than vh 11 ”, “vh 11  or more and less than vh 12 ”, “vh 12  or more and less than vh 13 ”, “vh 13  or more and less than vh 14 ”, and “vh 14  or more”. In a case of a “female” and an “iron”, a range in which a head speed is included is classified into five ranges such as “less than vh 15 ”, “vh 15  or more and less than vh 16 ”, “vh 16  or more and less than vh 17 ”, “vh 17  or more and less than vh 18 ”, and “vh 18  or more”. For example, in a case of a “male” and a “driver”, if a head speed is included in the range of “less than vh 1 ”, a score is 1 point which is the lowest score among 1 point to 5 points. If a head speed is included in the range of “vh 4  or more”, a score is 5 points which is the highest score among 1 point to 5 points. For example, in a case of a “female” and an “iron”, if a head speed is included in the range of “less than vh 15 ”, a score is 1 point which is the lowest score among 1 point to 5 points. If a head speed is included in the range of “vh 18  or more”, a score is 5 points which is the highest score among 1 point to 5 points. 
     Calculation of Total Score 
     The score calculation portion  212  calculates a total score on the basis of the score of the “impact” item and the score of the “speed” item. 
     For example, in a case where a score of each item is 5 points maximum, if a maximum of a total score is 100 points, the score calculation portion  212  may multiply the score of each item by 10 so that 50 points maximum is obtained, and may add all the scores together so as to calculate a total score. In the swing diagnosis screen illustrated in  FIG. 6 , a score of 5 points maximum of each item is displayed as a radar chart, and the score of each item is multiplied by 10, and 60 points obtained by adding all the scores together is a total score. 
     For example, the score calculation portion  212  may increase a weight of a highly important item in diagnosis (evaluation) of a swing and may add scores of the items together so as to calculate a total score. 
     1-1-5. Procedures of Swing Diagnosis Process 
       FIG. 15  is a flowchart illustrating examples of procedures of a swing diagnosis process (swing diagnosis method) performed by the processing section  21 . The processing section  21  (an example of a computer) performs the swing diagnosis process, for example, according to the procedures of the flowchart of  FIG. 15  by executing the swing diagnosis program  240  stored in the storage section  24 . Hereinafter, the flowchart of  FIG. 15  will be described. 
     First, the processing section  21  waits for the user  2  to perform a measurement starting operation (the operation in step S 2  in  FIG. 3 ) (N in step S 10 ), transmits a measurement starting command to the sensor unit  10  if the measurement starting operation is performed (Y in step S 10 ), and starts to acquire measured data from the sensor unit  10  (step S 12 ). 
     Next, the processing section  21  instructs the user  2  to take an address attitude (step S 14 ). The user  2  takes the address attitude in response to the instruction, and stands still (step S 4  in  FIG. 3 ). 
     Next, if a standing still state of the user  2  is detected by using the measured data acquired from the sensor unit  10  (Y in step S 16 ), the processing section  21  notifies the user  2  of permission of swing starting (step S 18 ). The processing section  21  outputs, for example, a predetermined sound, or an LED is provided in the sensor unit  10 , and the LED is lighted, so that the user  2  is notified of permission of swing starting. The user  2  confirms the notification and then starts a swing action (the action in step S 6  in  FIG. 3 ). 
     Next, the processing section  21  performs processes in step S 20  and subsequent steps after completion of the swing action of the user  2 , or from before completion of the swing action. 
     First, the processing section  21  computes an initial position and an initial attitude of the sensor unit  10  by using the measured data (measured data during standing still (at address) of the user  2 ) acquired from the sensor unit  10  (step S 20 ). 
     Next, the processing section  21  detects a swing starting timing a, a top timing, and an impact timing by using the measured data acquired from the sensor unit  10  (step S 22 ). 
     The processing section  21  computes a position and an attitude of the sensor unit  10  during the swing action of the user  2  in parallel to the process in step S 22 , or before and after the process in step S 22  (step S 24 ). 
     Next, in steps S 26  to S 30 , the processing section  21  computes values of various indexes regarding the swing by using at least some of the measured data acquired from the sensor unit  10 , the swing starting, top and impact timings detected in step S 22 , and the position and the attitude of the sensor unit  10  computed in step S 24 . 
     The processing section  21  computes the face angle ϕ in step S 26 . 
     The processing section  21  computes the club path (incidence angle) ψ in step S 28 . 
     The processing section  21  computes a head speed in step S 30 . 
     The processing section  21  generates the swing analysis data  244  by using the various indexes calculated in steps S 26  to S 30  (step S 32 ). 
     The processing section  21  calculates scores and a total score of predetermined items on the basis of the swing analysis data generated in step S 32  (step S 34 ). 
     The processing section  21  displays the swing diagnosis screen ( FIG. 6 ) on the display section  25  on the basis of information regarding the scores and total score of the predetermined items calculated in step S 34  (step S 36 ), and finishes the swing diagnosis process. 
     In the flowchart of  FIG. 15 , order of the respective steps may be changed as appropriate within an allowable range, some of the steps may be omitted or changed, and other steps may be added thereto. 
       FIG. 16  is a flowchart illustrating examples of procedures of a process (step S 34  in  FIG. 15 ) of calculating scores and a total score of predetermined items in the processing section  21  (score calculation portion  212 ). Hereinafter, the flowchart of  FIG. 16  will be described. 
     First, the processing section  21  calculates the relative face angle η on the basis of the face angle θ and the club path (incidence angle) ψ (step S 341 ). The processing section  21  may calculate the relative face angle η on the basis of the face angle ϕ and the club path (incidence angle) ψ after step S 28  in  FIG. 16  and before step S 32 . 
     Next, the processing section  21  calculates a score (a score of the “impact” item) corresponding to the relative face angle η and the club path (incidence angle) ψ by referring to the impact score table  245  stored in the storage section (step S 342 ). 
     Next, the processing section  21  determines sex (a male or a female) and the type of golf club (a driver or an iron) on the basis of the swing analysis data  244  (step S 343 ). 
     Next, the processing section  21  calculates a score (a score of the “speed” item) corresponding to the sex, the type of golf club, and a head speed by referring to the speed score table  246  stored in the storage section  24  (step S 344 ). 
     Finally, the processing section  21  calculates a total score on the basis of the score of the “impact” item calculated in step S 342  and the score of the “speed” item calculated in step S 344  (step S 345 ). 
     1-1-6. Operations and Effects 
     As described above, according to the swing diagnosis system  1  of the first embodiment, the swing diagnosis apparatus  20  calculates scores on the basis of a relationship between an incidence angle and an inclination of the head of the golf club  3  at impact and displays the scores on the display section  25 , on the basis of the swing analysis data  244  generated by using measured data in the sensor unit  10 , and can thus digitalize (level) and visually clearly show features of the swing till the impact. 
     Particularly, according to the swing diagnosis system  1  of the first embodiment, the swing diagnosis apparatus  20  can digitalize and clearly show features of the swing based on a relationship between the club path (incidence angle) ψ and the relative face angle η by using a score of the “impact” item. For example, the swing diagnosis apparatus  20  calculates a lower score as a hit ball is more easily curved with respect to the “impact” item, and can thus digitalize and clearly show features of the swing till the impact according to the extent to which a hit ball is easily curved. 
     According to the swing diagnosis system  1  of the first embodiment, the swing diagnosis apparatus  20  can digitalize and clearly show features of the swing based on a speed of the head of the golf club  3  at impact by using a score of the “speed” item. For example, the swing diagnosis apparatus  20  calculates a lower score as a speed of the head is lowered with respect to the “speed” item, and can thus digitalize and clearly show features of the swing according to the speed of the head at impact. 
     Therefore, the user  2  can recognize a level of the swing, strong points, weak points, problems, and the like in the swing thereof by using the scores of the “impact” item and the “speed” item obtained as diagnosis results based on the swing analysis data  244 . 
     According to the swing diagnosis system  1  of the first embodiment, since the swing analysis process and the swing diagnosis process are performed by using the sensor unit  10 , a large apparatus such as a camera is not required to be used, and there is less restriction in a location where the user  2  performs a swing. 
     1-2. Second Embodiment 
     In a second embodiment, the same constituent elements as those in the first embodiment are given the same reference numerals, description of the content overlapping the first embodiment will be omitted or will be made briefly, and the content different from the first embodiment will be described. 
     1-2-1. Configuration of Swing Diagnosis System 
       FIG. 17  is a diagram illustrating a configuration example of a swing diagnosis system according to the second embodiment. As illustrated in  FIG. 17 , a swing diagnosis system  1 A of the second embodiment is configured to include a sensor unit  10 , a swing analysis apparatus  30 , and a swing diagnosis apparatus  20 A. 
     If a user  2  performs the measurement starting operation in step S 2  in  FIG. 3 , the swing analysis apparatus  30  transmits a measurement starting command to the sensor unit  10 , and the sensor unit  10  receives the measurement starting command and starts measurement of three-axis accelerations and three-axis angular velocities. Communication between the sensor unit  10  and the swing analysis apparatus  30  may be wireless communication, and may be wired communication. 
     The swing analysis apparatus  30  notifies the user  2  of permission of swing starting, shown in step S 5  in  FIG. 3 , and then analyzes the swing action (step S 6  in  FIG. 3 ) in which the user  2  has hit the ball by using the golf club  3 . 
     The swing analysis apparatus  30  generates swing analysis data including information regarding a time point (date and time) at which the swing is performed, identification information or the sex of the user  2 , the type of golf club  3 , and an analysis result of the swing action, and transmits the swing analysis data to the swing diagnosis apparatus  20 A via a network  40  (refer to  FIG. 17 ). 
     The swing diagnosis apparatus  20 A receives the swing analysis data transmitted by the swing analysis apparatus  30  via the network  40 , and preserves the swing analysis data. Therefore, whenever the user  2  performs a swing action according to the procedures illustrated in  FIG. 3 , the swing analysis data generated by the swing analysis apparatus  30  is preserved in the swing diagnosis apparatus  20 A, and thus a swing analysis data list is built. 
     For example, the swing analysis apparatus  30  may be implemented by an information terminal (client terminal) such as a smart phone or a personal computer, and the swing diagnosis apparatus  20 A may be implemented by a server which processes requests from the swing analysis apparatus  30 . 
     The network  40  may be a wide area network (WAN) such as the Internet, and may be a local area network (LAN). The swing analysis apparatus  30  and the swing diagnosis apparatus  20 A may communicate with each other through, for example, near field communication or wired communication, without using the network  40 . 
     In the present embodiment, if the user  2  activates a swing diagnosis application via an operation section  23  (refer to  FIG. 18 ) of the swing analysis apparatus  30 , the swing analysis apparatus  30  performs communication with the swing diagnosis apparatus  20 A, and, for example, a selection screen of swing analysis data is displayed on the display section  25  of the swing analysis apparatus  30 . The selection screen includes a list of the swing analysis data for the user  2  included in the swing analysis data list preserved in the swing diagnosis apparatus  20 A. The user selects any one of the items of swing analysis data from the list of the swing analysis data via an operation of the swing analysis apparatus  30 . Consequently, the swing analysis apparatus  30  transmits selected information of the swing analysis data to the swing diagnosis apparatus  20 A. 
     The swing diagnosis apparatus  20 A receives the selected information, and calculates scores of predetermined items by using the selected swing analysis data. Specifically, in the same manner as in the first embodiment, the swing diagnosis apparatus  20 A calculates scores of respective two items such as an “impact” item and a “speed” item, for example, as 5 points maximum. The swing diagnosis apparatus  20 A may calculate a total score of the swing by using the scores of the two items. The swing diagnosis apparatus  20 A transmits information regarding the calculated scores and total score of the predetermined items to the swing analysis apparatus  30 . 
     The swing analysis apparatus  30  receives the information regarding the scores and total score of the predetermined items and displays a swing diagnosis screen as illustrated in  FIG. 6  on the display section  25 . The user  2  can understand scores and a total score of a plurality of items as diagnosis results for the swing analysis data on the left part on the basis of the swing diagnosis screen illustrated in  FIG. 6 . Particularly, if the user  2  can understand strong points or weak points in the user&#39;s swing on the basis of the swing diagnosis screen illustrated in  FIG. 6 . 
     1-2-2. Configuration of Sensor Unit and Swing Analysis Apparatus 
       FIG. 18  is a diagram illustrating configuration examples of the sensor unit  10  and the swing analysis apparatus  30 . As illustrated in  FIG. 18 , a configuration and a function of the sensor unit  10  are the same as those in the first embodiment, and thus description thereof will be omitted. 
     The swing analysis apparatus  30  is configured to include a processing section  31 , the communication section  22 , the operation section  23 , a storage section  34 , the display section  25 , the sound output section  26 , and a communication section  37 . However, the swing analysis apparatus  30  may have a configuration in which some of the constituent elements are deleted or changed as appropriate, or may have a configuration in which other constituent elements are added thereto. Configurations and functions of the communication section  22 , the operation section  23 , the display section  25 , and the sound output section  26  are the same as those in the first embodiment, and thus description thereof will be omitted. 
     The storage section  34  is constituted of, for example, various IC memories such as a read only memory (ROM), a flash ROM, and a random access memory (RAM), or a recording medium such as a hard disk or a memory card. The storage section  34  stores a program for the processing section  31  performing various calculation processes or a control process, or various programs or data for realizing application functions. 
     In the present embodiment, the storage section  34  stores a swing analysis program  340  which is read by the processing section  31  and is used for executing a swing analysis process. The swing analysis program  340  may be stored in a nonvolatile recording medium (computer readable recording medium) in advance, or the swing analysis program  340  may be received from a server (not illustrated) or the swing diagnosis apparatus  20 A by the processing section  31  via a network, and may be stored in the storage section  34 . 
     The storage section  34  stores golf club information  241 , physical information  242 , sensor attachment position information  243 , and swing analysis data  244 . 
     The storage section  34  is used as a work area of the processing section  31 , and temporarily stores data which is input from the operation section  23 , results of calculation executed by the processing section  31  according to various programs, and the like. The storage section  34  may store data which is required to be preserved for a long period of time among data items generated through processing of the processing section  31 . 
     The communication section  37  performs data communication with a communication section  27  (refer to  FIG. 19 ) of the swing diagnosis apparatus  20 A via the network  40 . For example, the communication section  37  performs a process of receiving the swing analysis data  244  from the processing section  31  after a swing analysis process is completed, and transmitting the swing analysis data to the communication section  27  of the swing diagnosis apparatus  20 A. For example, the communication section  37  performs a process of receiving information required to display the selection screen of the swing analysis data from the communication section  27  of the swing diagnosis apparatus  20 A and transmitting the information to the processing section  31 , and a process of receiving selected information on the selection screen from the processing section  31  and transmitting the selected information to the communication section  27  of the swing diagnosis apparatus  20 A. For example, the communication section  37  performs a process of receiving information (diagnosis result information (scores or a total score of predetermined items) based on the selected swing analysis data) required to display the swing diagnosis screen illustrated in  FIG. 6  from the communication section  27  of the swing diagnosis apparatus  20 A, and transmitting the information to the processing section  31 . 
     The processing section  31  performs a process of transmitting a control command to the sensor unit  10  via the communication section  22 , or various computation processes on data which is received from the sensor unit  10  via the communication section  22 , according to various programs. The processing section  31  performs a process of reading the swing analysis data  244  from the storage section  34 , and transmitting the swing analysis data to the swing diagnosis apparatus  20 A via the communication section  37 , according to various programs. The processing section  31  performs a process of transmitting the selected information of the swing analysis data to the swing diagnosis apparatus  20 A via the communication section  37 , and displaying the swing diagnosis screen illustrated in  FIG. 6  on the basis of the information received from the swing diagnosis apparatus  20 A, according to various programs. The processing section  31  performs other various control processes. 
     Particularly, in the present embodiment, by executing the swing analysis program  340 , the processing section  31  functions as a data acquisition portion  210 , a swing analysis portion  211 , an image data generation portion  213 , a storage processing portion  214 , a display processing portion  215 , and a sound output processing portion  216 , and performs a process (swing analysis process) of analyzing a swing action of the user  2 . Configurations and functions of the data acquisition portion  210 , the swing analysis portion  211 , the image data generation portion  213 , the storage processing portion  214 , the display processing portion  215 , and the sound output processing portion  216  are the same as those in the first embodiment, and thus description thereof will be omitted. The swing analysis process is also the same as that in the first embodiment, and thus description thereof will be omitted. 
     1-2-3. Configuration of Swing Diagnosis Apparatus 
       FIG. 19  is a diagram illustrating a configuration example of the swing diagnosis apparatus  20 A. As illustrated in  FIG. 19 , in the present embodiment, the swing diagnosis apparatus  20 A is configured to include a processing section  21 A, the communication section  27 , and a storage section  24 A. However, the swing diagnosis apparatus  20 A may have a configuration in which some of the constituent elements are deleted or changed as appropriate, or may have a configuration in which other constituent elements are added thereto. 
     The storage section  24 A is constituted of, for example, various IC memories such as a ROM, a flash ROM, and a RAM, or a recording medium such as a hard disk or a memory card. The storage section  24 A stores a program for the processing section  21 A performing various calculation processes or a control process, or various programs or data for realizing application functions. 
     In the present embodiment, the storage section  24 A stores a swing diagnosis program  240 A which is read by the processing section  21 A and is used for executing a swing diagnosis process. The swing diagnosis program  240 A may be stored in a nonvolatile recording medium (computer readable recording medium) in advance, or the swing diagnosis program  240 A may be received from a server (not illustrated) by the processing section  21 A via a network, and may be stored in the storage section  24 A. 
     In the present embodiment, the storage section  24 A stores (preserves) a swing analysis data list  247  including a plurality of items of swing analysis data  244  generated by the swing analysis apparatus  30 . In other words, the swing analysis data  244  generated whenever the processing section  31  of the swing analysis apparatus  30  analyzes a swing action of the user  2  is sequentially added to the swing analysis data list  247 . 
     In the present embodiment, the storage section  24 A stores the impact score table  245  and the speed score table  246 . 
     The storage section  24 A is used as a work area of the processing section  21 A, and temporarily stores results of calculation executed by the processing section  21 A according to various programs, and the like. The storage section  24 A may store data which is required to be preserved for a long period of time among data items generated through processing of the processing section  21 A. 
     The communication section  27  performs data communication with the communication section  37  (refer to  FIG. 18 ) of the swing analysis apparatus  30  via the network  40 . For example, the communication section  27  performs a process of receiving the swing analysis data  244  from the communication section  37  of the swing analysis apparatus  30 , and transmitting the swing analysis data  244  to the processing section  21 A. For example, the communication section  27  performs a process of transmitting information required to display the selection screen of the swing analysis data to the communication section  37  of the swing analysis apparatus  30 , or a process of receiving selected information on the selection screen of the swing analysis data from the communication section  37  of the swing analysis apparatus  30  and transmitting the selected information to the processing section  21 A. For example, the communication section  27  performs a process of receiving diagnosis result information (scores or a total score of predetermined items) based on the swing analysis data  244  selected according to the selected information from the processing section  21 A, and transmitting the information to the communication section  37  of the swing analysis apparatus  30 . For example, the communication section  27  performs a process of receiving information required to display the swing diagnosis screen illustrated in  FIG. 6  from the processing section  21 A and transmitting the information to the communication section  37  of the swing analysis apparatus  30 . 
     The processing section  21 A performs a process of receiving the swing analysis data  244  from the swing analysis apparatus  30  via the communication section  27  and storing the swing analysis data  244  in the storage section  24 A (adding the swing analysis data to the swing analysis data list  247 ), according to various programs. The processing section  21 A performs a process of receiving selected information from the swing analysis apparatus  30  via the communication section  27 , and transmitting information required to display the swing diagnosis screen illustrated in  FIG. 6  to the swing analysis apparatus  30 , according to various programs. The processing section  21 A performs other various control processes. 
     Particularly, in the present embodiment, the processing section  21 A functions as a data acquisition portion  217 , a score calculation portion  212 , and a storage processing portion  218  by executing the swing diagnosis program  240 A, and performs a diagnosis process (swing diagnosis process) on the swing analysis data  244  selected from the swing analysis data list  247 . 
     The data acquisition portion  217  performs a process of receiving the swing analysis data  244  received from the swing analysis apparatus  30  by the communication section  27  and transmitting the swing analysis data  244  to the storage processing portion  218 . The data acquisition portion  217  performs a process of receiving various pieces of information received from the swing analysis apparatus  30  by the communication section  27  and transmitting the information to the score calculation portion  212 . 
     The storage processing portion  218  performs read/write processes of various programs or various data for the storage section  24 A. The storage processing portion  218  performs a process of receiving the swing analysis data  244  from the data acquisition portion  217  and storing the swing analysis data  244  in the storage section  24 A (adding the swing analysis data to the swing analysis data list  247 ), a process of reading the swing analysis data  244  from the swing analysis data list  247  stored in the storage section  24 A, or the like. For example, the storage processing portion  218  performs a process of reading the impact score table  245  or the speed score table  246  stored in the storage section  24 A. 
     The score calculation portion  212  performs a process of calculating scores of predetermined items on the basis of data regarding a swing. In the present embodiment, the data regarding the swing is the swing analysis data  244  selected based on the selected information. A function of the score calculation portion  212  or a score calculation process performed by the score calculation portion  212  is the same as that in the first embodiment, and thus description thereof will be omitted. 
     1-2-4. Procedures of Swing Diagnosis Process (Swing Diagnosis Method) 
       FIG. 20  is a flowchart illustrating examples of procedures of a process performed by the processing section  31  of the swing analysis apparatus  30  in relation to the swing diagnosis process.  FIG. 21  is a flowchart illustrating examples of procedures of the swing diagnosis process (swing diagnosis method) performed by the processing section  21 A of the swing diagnosis apparatus  20 A. The processing section  21 A (an example of a computer) of the swing diagnosis apparatus  20 A performs the swing diagnosis process, for example, according to the procedures of the flowchart of  FIG. 21  by executing the swing diagnosis program  240 A stored in the storage section  24 A. Hereinafter, the flowcharts of  FIGS. 20 and 21  will be described. 
     First, the processing section  31  of the swing analysis apparatus  30  transmits user identification information allocated to the user  2 , to the swing diagnosis apparatus  20 A (step S 100  in  FIG. 20 ). 
     Next, the processing section  21 A of the swing diagnosis apparatus  20 A receives the user identification information, and transmits list information of the swing analysis data  244  corresponding to the user identification information (step S 200  in  FIG. 21 ). 
     Next, the processing section  31  of the swing analysis apparatus  30  receives the list information of the swing analysis data  244 , and displays a selection screen of the swing analysis data on the display section  25  (step S 110  in  FIG. 20 ). 
     The processing section  31  of the swing analysis apparatus  30  waits for the swing analysis data  244  to be selected on the selection screen of the swing analysis data (N in step S 120  in  FIG. 20 ), and transmits selected information of the swing analysis data to the swing diagnosis apparatus  20 A (step S 130  in  FIG. 20 ) if the information is selected (Y in step S 120  in  FIG. 20 ). 
     Next, the processing section  21 A of the swing diagnosis apparatus  20 A receives the selected information of the swing analysis data (step S 210  in  FIG. 21 ), and calculates scores and a total score of predetermined items on the basis of the swing analysis data  244  which is selected on the basis of the selected information (step S 220  in  FIG. 21 ). A detailed procedure in step S 220  is the same as the procedure in  FIG. 16 . 
     Next, the processing section  21 A of the swing diagnosis apparatus  20 A transmits (outputs) information regarding the scores and the total score of the predetermined items to the swing analysis apparatus  30  (step S 230  in  FIG. 21 ), and finishes the swing diagnosis process. 
     The processing section  31  of the swing analysis apparatus  30  receives the information regarding the scores and the total score of the predetermined items, displays the swing diagnosis screen ( FIG. 6 ) on the display section  25  (step S 140  in  FIG. 20 ), and finishes the process. 
     In the flowchart of  FIG. 20 , order of the respective steps may be changed as appropriate within an allowable range, some of the steps may be omitted or changed, and other steps may be added thereto. Similarly, in the flowchart of  FIG. 21 , order of the respective steps may be changed as appropriate within an allowable range, some of the steps may be omitted or changed, and other steps may be added thereto. 
     1-2-5. Operations and Effects 
     As described above, in the swing diagnosis system  1 A of the second embodiment, the swing analysis apparatus  30  generates the swing analysis data  244  by using measured data in the sensor unit  10 . The swing diagnosis apparatus  20 A calculates scores on the basis of a relationship between an incidence angle and an inclination of the head of the golf club  3  at impact by using the selected swing analysis data  244 . The swing analysis apparatus  30  displays the scores calculated by the swing diagnosis apparatus  20 A on the display section  25 , and can thus digitalize and visually clearly show features of the swing till the impact. 
     In the same manner as in the swing diagnosis system  1  of the first embodiment, according to the swing diagnosis system  1 A of the second embodiment, it is possible to digitalize and clearly show features of the swing based on a relationship between the club path (incidence angle) ψ and the relative face angle η by using a score of the “impact” item. 
     In the same manner as in the swing diagnosis system  1  of the first embodiment, according to the swing diagnosis system  1 A of the second embodiment, it is possible to digitalize and clearly show features of the swing based on a speed of the head of the golf club  3  at impact by using a score of the “speed” item. 
     Therefore, the user  2  can recognize a level of the swing, strong points, weak points, problems, and the like in the swing thereof by using the scores of the “impact” item and the “speed” item obtained as diagnosis results based on the swing analysis data  244 . 
     According to the swing diagnosis system  1 A of the second embodiment, it is possible to reduce a load on the swing analysis apparatus  30  since the swing diagnosis apparatus  20 A performs the swing diagnosis process (score calculation process). 
     According to the swing diagnosis system  1 A of the second embodiment, it is possible to achieve the same effects as in the swing diagnosis system  1  of the first embodiment. 
     2. Modification Examples 
     The invention is not limited to the present embodiment, and may be variously modified within the scope of the spirit of the invention. 
     2-1. Swing Diagnosis System 
     In the second embodiment, the swing diagnosis apparatus  20 A may perform a part of a process (swing analysis process) performed by the swing analysis apparatus  30 , and the swing analysis apparatus  30  may perform a part of a process (swing diagnosis process) performed by the swing diagnosis apparatus  20 A. 
     In the second embodiment, the swing diagnosis system  1 A may be configured to include a plurality of sensor units  10  and a plurality of swing analysis apparatuses  30 . 
     2-2. Swing Analysis Process 
     A plurality of sensor units  10  may be attached to the golf club  3  or parts such as the arms or the shoulders of the user  2 , and the swing analysis portion  211  may perform a swing analysis process by using measured data from the plurality of sensor units  10 . 
     In the embodiments, the swing analysis portion  211  detects impact by using the square root of the square sum as shown in Equation (2) as a combined value of three-axis angular velocities measured by the sensor unit, but, as a combined value of three-axis angular velocities, for example, a square sum of three-axis angular velocities, a sum or an average of three-axis angular velocities, or the product of three-axis angular velocities may be used. Instead of a combined value of three-axis angular velocities, a combined value of three-axis accelerations such as a square sum or a square root of three-axis accelerations, a sum or an average value of three-axis accelerations, or the product of three-axis accelerations may be used. 
     2-3. Swing Diagnosis Process 
     In the respective embodiments, some or all values of indexes included in the swing analysis data  244  may be changed, and the score calculation portion  212  may calculate scores and a total score of predetermined items on the basis of data in which some or all values of the indexes are changed. The score calculation portion  212  may calculate scores and a total score of predetermined items on the basis of data (for example, all indexes are manually input data) in which all values of indexes indicating features of a swing are pseudo-values. 
     In the embodiments, the score calculation portion  212  calculates scores of two items including the “impact” item and the “speed” item, but may not calculate a score of the “speed” item, and may calculate scores of other items. In the respective embodiments, the score calculation portion  212  calculates a total score, but may not calculate a total score. 
     In the respective embodiments, the score calculation portion  212  calculates scores of predetermined items by using the score tables, but may use equations instead of the score tables. 
     In the embodiments, the score calculation portion  212  may also function as the swing analysis portion  211 , and may perform a swing diagnosis process (a swing analysis process and a score calculation process) including the swing analysis process on the basis of measured data (an output signal from an inertial sensor) from the sensor unit  10 , which is data regarding a swing. 
     2-4. Others 
     In the embodiments, the acceleration sensor  12  and the angular velocity sensor  14  are built into and are thus integrally formed as the sensor unit  10 , but the acceleration sensor  12  and the angular velocity sensor  14  may not be integrally formed. Alternatively, the acceleration sensor  12  and the angular velocity sensor  14  may not be built into the sensor unit  10 , and may be directly mounted on the golf club  3  or the user  2 . In the above-described embodiment, the sensor unit  10  and the swing diagnosis apparatus  20  or the swing analysis apparatus  30  are separately provided, but may be integrally formed so as to be attached to the golf club  3  or the user  2 . The sensor unit  10  may have some of the constituent elements of the swing diagnosis apparatus  20  or the swing analysis apparatus  30  along with the inertial sensor (for example, the acceleration sensor  12  or the angular velocity sensor  14 ). 
     In the embodiments, the swing diagnosis system (swing diagnosis apparatus) diagnosing a golf swing has been exemplified, but the invention is applicable to a swing diagnosis system (swing diagnosis apparatus) diagnosing a swing in various sports such as tennis or baseball. 
     The above-described embodiments and modification examples are only examples, and the invention is not limited thereto. For example, the embodiments and the respective modification examples may be combined with each other as appropriate. 
     For example, the invention includes substantially the same configuration (for example, a configuration in which functions, methods, and results are the same, or a configuration in which objects and effects are the same) as the configuration described in the embodiments. The invention includes a configuration in which an inessential part of the configuration described in the embodiments is replaced with another part. The invention includes a configuration which achieves the same operation and effect or a configuration capable of achieving the same object as in the configuration described in the embodiments. The invention includes a configuration in which a well-known technique is added to the configuration described in the embodiments. 
     The entire disclosure of Japanese Patent Application No. 2015-148641 filed Jul. 28, 2015 is expressly incorporated by reference herein.