Electronic equipment, arm swinging analysis method, and program

Abstract

To provide electronic equipment capable of specifying an elbow bending angle when a user swings his or her arm more easily, and to provide an arm swinging analysis method, and a program.SOLUTION: The electronic equipment includes a processing unit for specifying a cyclical change related to a user's arm swinging from three-dimensional acceleration measured by a measuring unit for measuring three-dimensional acceleration. The processing unit defines a two-dimensional plane including the user's arm swinging plane from the three-dimensional acceleration measured at the user's wrist, detects a cyclical change as a movement on the arc around the user's shoulder in the two-dimensional plane, obtains the direction of a line segment connecting the wrist and the shoulder and calculates a bending angle of the elbow from the three-dimensional acceleration.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to an electronic device and an arm swing analysis method. [Background technology]

[0002] There is a technology that uses electronic devices worn on the human body, such as the wrist (arm) or waist, to measure and analyze the wearer's motion state, and supports the wearer in maintaining and improving appropriate motion. In the human body, various periodic acceleration and angular velocity changes occur, such as arm swing, depending on the motion of walking, running, etc. (hereinafter collectively referred to as running and walking). Based on the measurement results of these periodic changes, the user's posture during running and walking, its changes, shaking and bias, etc. can be evaluated in addition to the amount and quantity of running and walking.

[0003] One such evaluation value is the bending angle of the elbow (elbow angle) (for example, Patent Document 1). This elbow angle may also be required when calculating other evaluation values. Conventionally, the elbow angle is obtained by using multiple sensors in combination. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-146987 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, wearing multiple electronic devices or using multiple measuring devices in combination to determine the elbow bending angle when swinging the arm poses issues such as increased costs, weight and processing load, and is time-consuming.

[0006] An object of the present invention is to provide an electronic device and an arm swing analysis method that can more easily identify the elbow bending angle when a user swings their arm. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention provides a processing unit for identifying a periodic change associated with a user's arm swing from the three-dimensional acceleration measured by a measuring unit that measures the three-dimensional acceleration, The processing unit defines a two-dimensional plane including a plane of the user's arm swing from the three-dimensional acceleration measured at the user's wrist, detects the periodic change as a movement on an arc centered on the user's shoulder within the two-dimensional plane, and calculates an elbow bending angle by determining a direction of a line segment connecting the wrist and the shoulder from the three-dimensional acceleration. It is an electronic device. Effect of the Invention

[0008] According to the present invention, it is possible to more easily specify the elbow bending angle when the user swings his / her arm in the electronic device. [Brief description of the drawings]

[0009] [Figure 1] 1 is a diagram showing an overall configuration of a measurement system according to a first embodiment. [Diagram 2] FIG. 1 is a diagram showing a state in which the electronic device is worn on a user's arm. [Diagram 3] FIG. 2 is a block diagram showing a functional configuration of the electronic device. [Figure 4] FIG. 2 is a diagram illustrating a measurement by an acceleration sensor. [Diagram 5] 11A and 11B are diagrams illustrating measurement of arm swing and calculation of angle. [Figure 6] 5 is a flowchart showing a control procedure of an index calculation control process according to the first embodiment. [Figure 7] 13 is a flowchart showing a control procedure for an arm swing acceleration calculation process. [Figure 8] 13A and 13B are diagrams illustrating a method of obtaining a swing width in a modified example. [Figure 9] 13 is a flowchart showing a control procedure of an index calculation control process according to a modified example. [Figure 10]FIG. 11 is a diagram illustrating a sensor configuration according to a second embodiment. [Figure 11] FIG. 11 is a diagram illustrating acceleration associated with arm swing in the second embodiment. [Figure 12] FIG. 11 is a diagram illustrating a sensor configuration according to a second embodiment. [Figure 13] 13 is a flowchart showing a control procedure of an index calculation control process according to the second embodiment. [Figure 14] 13 is a flowchart showing a control procedure for arm swing acceleration calculation processing in the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. [First embodiment] FIG. 1 is a diagram showing the overall configuration of a measurement system 100 according to the first embodiment. The measurement system 100 includes electronic devices 1 and 4 .

[0011] The electronic device 1 is a wrist-worn device such as an electronic watch or a smart watch. The electronic device 1 is worn on the user's arm, particularly on the wrist, and can measure the wrist motion state mainly during activities such as walking and running.

[0012] FIG. 2 shows the electronic device 1 worn on the arm.

[0013] The electronic device 4 is a terminal device such as a smartphone, but may be a general-purpose electronic computer. The electronic device 1 and the electronic device 4 can communicate with each other by wireless communication, for example, Bluetooth (registered trademark) or wireless LAN. The electronic device 1 and the electronic device 4 do not necessarily need to be connected at all times during an activity. However, in the following description, the electronic device 4 is assumed to be connected to the electronic device 1 for communication during the activity.

[0014] FIG. 3 is a block diagram showing the functional configuration of the electronic device 1. As shown in FIG. The electronic device 1, such as an electronic wristwatch which is the computer of this embodiment, comprises a CPU 11 (Central Processing Unit), a RAM 12 (Random Access Memory) (processing unit), a memory 13, a display unit 14, an operation receiving unit 15, a communication unit 16, a timing unit 17, a measurement unit 18 (first measurement unit), an alarm operation unit 19, and the like.

[0015] The CPU 11 is a processor that performs arithmetic processing. The CPU 11 performs arithmetic processing and generally controls the operation of the electronic device 1. The CPU 11 may have a single processor, or may have multiple processors that perform calculations in parallel or operate separately depending on the application.

[0016] The RAM 12 provides a working memory space for the CPU 11. The RAM 12 stores temporary data.

[0017] The memory 13 is, for example, a non-volatile memory such as a flash memory. The memory 13 stores a program 131 and setting data. The program 131 controls the execution of data processing and analysis of activity measurement described below. In particular, the program 131 includes control of a process for identifying periodic changes related to arm swing during walking or running of the user and calculating an arm swing index.

[0018] The display unit 14 displays various information under the control of the CPU 11. The display unit 14 has a display screen such as a liquid crystal display or an organic EL (Electro-Luminescent) display. The display unit 14 may be capable of color display, or may display with a limited number of colors.

[0019] The operation reception unit 15 has a push button switch or the like, and receives an input operation from outside. The operation reception unit 15 may have a touch panel in addition to or instead of the push button switch. The touch panel is located so as to overlap the display screen.

[0020] The communication unit 16 controls communication with external devices. The communication unit 16 can control communication according to a communication protocol such as Bluetooth or wireless LAN as described above. The communication unit 16 may have a module for performing communication via Bluetooth. Alternatively, the communication unit 16 may have a network card for performing communication via wireless LAN.

[0021] The time counter 17 counts the passage of time based on a clock signal of a certain frequency generated by an oscillation circuit (not shown) and holds the current time. The time counter 17 may have, for example, an RTC (Real Time Clock). The time counter 17 may also have a logical slowing and fast circuit that adjusts the difference between the oscillation frequency of the oscillation circuit and the passage of time. The time counter 17 may not have a dedicated counter for counting the passage of time, and the CPU 11 may count the output of the logical slowing and fast circuit.

[0022] The measurement unit 18 has an acceleration sensor 181. The acceleration sensor 181 measures acceleration in three orthogonal axial directions (three-dimensional acceleration).

[0023] The annunciation operation unit 19 performs a predetermined annunciation operation other than displaying on the display screen of the display unit 14. Examples of the annunciation operation include generation of a beep, output of a voice, output of a vibration, emission or blinking of a light-emitting element, etc. The annunciation operation unit 19 may have some or all of known components related to these operations. The electronic device 1 as a computer includes at least the CPU 11, the RAM 12, and the memory 13 described above.

[0024] FIG. 4 is a diagram for explaining the measurement by the acceleration sensor 181. As shown in FIG. 4(a), the acceleration sensor 181 measures three-dimensional acceleration in a coordinate system represented by x-axis and z-axis perpendicular to the display surface of the electronic device 1 fixed to the wrist of the user, and y-axis perpendicular to the display surface. When the electronic device 1 is worn on the wrist, the z-axis is usually the extension direction of the arm. In other words, the z-axis direction is the direction from the wrist to the elbow of the user. The x-axis direction is the direction perpendicular to the y-axis and z-axis, approximately parallel to the back of the hand, and from the little finger side to the thumb side. The arm swing occurs in the xz plane, which is a two-dimensional plane, except for the palm-turning motion described later.

[0025] 4(b), when a user wearing the electronic device 1 runs or walks with his / her arms swinging, the arm extends from the shoulder Bs to the wrist Bw, bending at the elbow Be. The wrist Bw moves back and forth along a pendulum-like path with the shoulder Bs as a support position every two steps.

[0026] At this time, in the stationary coordinate system in the figure on the left, the force acting on the wrist Bw is the resultant force of gravity (gravitational acceleration g) and the force from the arm. The force acting from the arm is the sum of the stress against gravity (acceleration wg), the centripetal force (acceleration wc; centripetal acceleration) generated by the pendulum motion, and the force acting from the arm swing caused by the muscle strength of the arm (acceleration wt). The stress against gravity does not necessarily cancel out the component of gravity along the direction of arm movement during the arm swing. In other words, the stress only cancels out the component of gravity in the direction connecting the shoulder Bs and wrist Bw.

[0027] If we look at this situation in the coordinate system (xz plane) fixed to the wrist Bw in the right figure, this coordinate system becomes a rotating coordinate system. Therefore, the wrist Bw is subjected to centrifugal force (acceleration ac), and also receives stress (acceleration wc) from the arm that offsets the centrifugal force ac.

[0028] In the acceleration sensor 181, an acceleration detection element is supported by a support member, and detects the force that the detection element receives from the support member. Therefore, gravity and centrifugal force that the detection element and the support member receive simultaneously are not detected by the acceleration sensor 181 (shown by dotted lines). At the wrist Bw, the acceleration sensor 181 of the electronic device 1 detects the sum of accelerations wc, wg, and wt according to stress.

[0029] Next, measurement of arm swing will be described. Fig. 5 is a diagram for explaining measurement of arm swing and calculation of angle. Here, the position of the shoulder Bs is shown as fixed. Therefore, Fig. 5 shows only the position change according to the arm swing. As described above, the bending angle of the elbow (elbow angle θe) does not change substantially during the time span of one cycle (two steps) of arm swing. Therefore, the wrist Bw can be considered to move back and forth on an arc of radius L centered on the shoulder Bs. In other words, the radius L is the distance between the shoulder Bs and the wrist Bw. The angle between the two line segments connecting the shoulder Bs and the wrist Bw at both ends (reversal points) where the direction of the arm swing changes (switches) within the display surface (arm swing surface) of Figure 5 is the angle of the arm swing (magnitude of the arm swing).

[0030] A two-dimensional plane is defined with the wrist Bw as the origin, the direction of the shoulder Bs as the R axis, and the direction perpendicular to the R axis and the movement direction of the wrist Bw as the T axis. Here, the plane including the R axis and the T axis is parallel (identical) to the plane including the x axis and the z axis. The coordinate system represented by these RT axes also rotates according to the arm swing. The angle difference θw (first angle) between the RT axis and the xz axis depends on the elbow angle θe of the bending angle of the elbow, and is constant under the condition that the elbow angle θe is fixed as described above. In the two-dimensional coordinate system fixed to the wrist, accelerations wg and wc according to the stress are generated in the R axis direction (the direction perpendicular to the circular arc along which the wrist Bw reciprocates), and the acceleration in the T axis direction is the sum of the acceleration wt according to the arm swing and the acceleration gt of the T axis component of the gravitational acceleration g.

[0031] Among these acceleration components, the acceleration wt in the T-axis direction fluctuates sinusoidally in positive and negative directions around wt=0 during one arm swing cycle. On the other hand, in a normal arm swing, the position of the wrist Bw is almost always lower in the vertical direction than the position of the shoulder Bs. Therefore, the accelerations wg and wc in the R-axis direction have a positive offset value (DC component) added to the sinusoidal periodic vibration. By performing low-pass filtering (LPF) on the acceleration change in the plane including the RT axis (i.e., the xz axis), the offset component (the sum of the offset component of the acceleration wg and the offset component of the acceleration wc), which is the DC component of the acceleration in the R-axis direction, is selectively extracted. This acceleration direction in the xz plane of the coordinate system fixed to the wrist is specified as the R-axis direction. In other words, once a vector (xr, zr) indicating the R-axis direction is determined, the angle difference θw from the z-axis to the R-axis can be obtained, for example, by taking the inner product of this vector and the z-axis direction (0, 1). By specifying the R-axis direction, the direction of the T-axis perpendicular to the R-axis is also specified. Note that the actually obtained R-axis direction, i.e., the angle difference θw, has some variation. Therefore, for example, a representative value of the angle difference θw(t) obtained at each timing t of one arm swing cycle, i.e., an average value or a median value, may be determined as the angle difference θw of this one cycle. The LPF may be performed, for example, by determining an appropriate moving window according to the cutoff frequency, performing FFT processing on the data in the moving window, and then cutting the spectrum intensity of frequencies equal to or higher than the cutoff frequency and performing inverse conversion. Alternatively, it may be simpler to subtract the average value in the moving window. Also, more sequentially, a new arithmetic average value may be obtained by adding the most recent angle difference θw(t) multiplied by a coefficient k according to the number of data in the reference cycle of the LPF and the arithmetic average value up to the previous time multiplied by a coefficient (1-k), and subtracting this arithmetic average value from the angle difference θw(t). Note that measurement data that is no longer needed because it is out of the range used by the LPF may be erased one by one.

[0032] As described above, the gravitational acceleration g is not measured, and therefore the acceleration gt of the T-axis direction component is not included in the measurement value of the acceleration sensor 181. However, the sum of the acceleration wg of the R-axis direction component and the acceleration gt of the T-axis direction component is the gravitational acceleration g. Therefore, if the acceleration wg is specified, the acceleration gt of the T-axis direction component can be calculated. In other words, the acceleration component in the direction along the T-axis is specified as the sum of the acceleration wt and the acceleration gt.

[0033] The stress (acceleration wc) corresponding to the centrifugal force depends on the movement speed v of the wrist Bw, and is expressed as wc = v 2 / L. At both ends of the arm swing (the turning points of the arm swing), the movement speed v = 0. The movement speed v of the wrist Bw is found by integrating the sum of the acceleration wt of the arm swing and the acceleration gt of the T-axis component of the gravitational acceleration from the turning point. The T-axis component of the measured acceleration is essentially equal to the acceleration wt. Therefore, after calculating the acceleration gt of the T-axis component as described above, the movement speed v at each timing can be found by accumulating (integrating) the acceleration (wt + gt) with the turning point as the base. The accumulation of errors is kept to a minimum by resetting the integration at each turning point.

[0034] The turning point is determined, for example, by the following procedure. Based on the RT axis direction specified as above, the acceleration wt in the T axis direction, i.e., the arm swing direction, is calculated. An arbitrary time is set as a reference, and the acceleration wt from this time is integrated to provisionally calculate the arm swing direction speed vt at each time. Since the speed (initial speed) at the reference time is not specified, the speed vt is a value with an offset. The average value (average value) of the speeds vt obtained at each time is the offset value. In a situation where the turning point is not specified, the phase of the arm swing is not specified, so the averaging period needs to be sufficiently longer than the arm swing period. For example, the averaging period may be about 8 to 10 seconds. The moving speed v is correctly determined by subtracting the average value (offset value) obtained from each speed vt obtained earlier. The point where this speed vt becomes zero is the turning point.

[0035] Note that before the first turning point is identified (before the RT axis direction is identified) or when the arm swing is small and unclear, it is difficult to identify the point where the integrated moving speed v becomes zero. In such cases, the turning point of the arm swing can be estimated by other methods, such as the timing when the acceleration in the x axis direction becomes a maximum (minimum) value. The time between adjacent turning points is the time required for one arm swing, and two of these times, that is, the time it takes for one arm to swing and return to the vicinity of its original position, is defined as the arm swing period.

[0036] The acceleration wg is calculated by subtracting the acceleration wc corresponding to the moving speed v from the acceleration wr, which is the R-direction component of the measured acceleration (i.e., wr = wc + wg). The angle φt between the R-axis direction and the vertical direction at a certain time t is φt = cos -1 (wg / g). Therefore, the acceleration gt of the T-axis component of the gravitational acceleration g can be calculated as gt = g sin(φt).

[0037] The radius L is determined by the upper arm length Lu, the forearm length Lf, and the elbow angle θe. The arm length Lu+Lf is statistically dependent on the height. The ratio of the length Lu to the length Lf is generally a fixed value. The ratio of the height to the arm length Lu+Lf and the ratio of the length Lu to the length Lf are each determined in advance and stored in the memory 13. The electronic device 1 acquires the height information of the user in advance, and when the elbow angle θe is determined, the radius L is obtained. The values ​​of these ratios do not have to be fixed. They may be set and held in more detail according to information such as age, sex, race (country), weight, and foot size. The ratio of the length Lu to the length Lf may be 1:1. Alternatively, the lengths Lu and Lf may be determined by accepting a direct input of an actual measurement value by the user through the operation acceptance unit 15.

[0038] When the lengths Lu and Lf are different, for example, when a perpendicular line is drawn from the wrist Bw to the line segment Bs-Be (or its extension), the length L1 of the perpendicular line is L1 = Lf sin(θe). The length L2 from the shoulder Bs to the intersection with this perpendicular line is L2 = Lu - Lf cos(θe). Therefore, L = (L12 +L2 2 ) 1 / 2 =(Lu 2 +Lf 2 -2Lu Lf cos(θe) 1 / 2 It is required.

[0039] The elbow angle θe is calculated by subtracting the sum of the angle θs of the shoulder Bs and the angle of the wrist Bw (angle difference θw) in the triangle formed by the shoulder Bs, elbow Be, and wrist Bw from 180. If the lengths Lu and Lf are determined in addition to the angle difference θw calculated as above, the angle θs can be determined. For example, based on the length of the perpendicular line from the elbow Be to the line segment Bs-Bw, Lf·sin(θw)=Lu·sin(θs). Therefore, θs=sin -1 It can be calculated as ((Lf / Lu)sin(θw)).

[0040] When the ratio of length Lu to length Lf is 1:1, the triangle formed by shoulder Bs, elbow Be, and wrist Bw is an isosceles triangle. In other words, the angle difference θw is equal to the angle θs. In this case, L=Lu·(2(1-cos(θe))) 1 / 2 In addition, the elbow angle θe = 180-2 θw. Therefore, the radius L can also be calculated as L = 2 Lu cos(θw).

[0041] The above-mentioned moving speed v is further integrated from the turning point (i.e., the acceleration component in the T-axis direction is integrated twice, and is integrated in the numerical processing of discrete values), to obtain the moving amount Lt of the arm from the turning point. The moving amount Lt is the length of the arc. Therefore, the angle φ according to the moving amount Lt is calculated by φ[rad]=Lt / L. The angle φ between the turning points is obtained as the arm swing angle φ0 (the magnitude of the arm swing) in a half cycle. Note that since there may be variation in the measurement and in the arm swing itself, multiple arm swing angles φ0 may be averaged and output. These arm swing cycle and the magnitude of the arm swing are included in the arm swing index for evaluating the user's arm swing state. The arm swing index may also include the angles of both ends of the arm swing and the elbow angle θe.

[0042] In the above, we have shown a case where the user ideally swings their arms within the xz plane, but there are users who rotate their wrists around the z axis (turning their hands) or move their wrists in the y direction (even when not rotating around the z axis) during each arm swing period when running or walking. In these cases, the acceleration component that would normally appear in the x direction component may be dispersed into the y direction component. In this embodiment, a coordinate transformation is performed to rotate the Z axis so that the acceleration in the y direction becomes zero for the three-axis acceleration measured by the acceleration sensor 181 attached to the wrist Bw. This coordinate transformation places the three-axis acceleration on the xz plane to calculate the arm swing angle. The magnitude of the x component after transformation is sgn(x)·(x 2 +y 2 ) 1 / 2 It should be noted that if it can be assumed that no force in the y-axis direction is applied to the user's arm swing, or if the force in the y-axis direction is negligibly small, the above coordinate conversion does not need to be performed.

[0043] 6 is a flowchart showing a control procedure of a control process related to arm swing index calculation by the CPU 11 in the electronic device 1 of this embodiment. This control process including the arm swing analysis method of this embodiment is started upon receipt of a command to start measuring an activity amount from an app / software related to walking or running activities, for example, and is repeatedly executed continuously until a command to end the measurement is received.

[0044] The CPU 11 performs initial setting (S1). The CPU 11 sets the upper arm length Lu and the forearm length Lf from the acquired height value. As described above, the CPU 11 may further determine the lengths Lu and Lf based on information such as age and sex. Alternatively, the lengths Lu and Lf may be directly input and set as they are.

[0045] The CPU 11 acquires measurement data from the acceleration sensor 181 at set intervals (S2). The set intervals correspond to a predetermined time resolution. The measurement data is expressed in the above-mentioned xyz coordinate system.

[0046] The CPU 11 uses the data from the most recent set time among the measurement data to determine whether the user is running or walking (S3). When running or walking, the measurement value of the acceleration sensor 181 shows periodic fluctuations related to the above-mentioned arm swing at a cycle of one step and / or two steps, as described above. In addition, not only arm swing but also periodic fluctuations of a specific directional component such as up and down movement corresponding to raising and lowering of legs (take-off / landing) may be superimposed on the measurement value. The CPU 11 may determine that the user is in a running or walking state when vibrations of a reference or higher amplitude intensity continue for a reference time or longer within a range of a cycle (frequency) assumed as running or walking. The CPU 11 may distinguish between running and walking separately. In addition, depending on the type of activity that is set, the CPU 11 may determine that the user is not running or walking in a case other than the set one (walking when set to running, or running when set to walking).

[0047] If it is determined that the person is not running or walking (S3; NO), the CPU 11 proceeds to step S18. If it is determined that the person is running or walking (S3; YES), the CPU 11 detects the timing of the arm swing to change direction (S4). As described above, the timing of the change direction is the timing when the moving speed v becomes zero and the positive and negative signs of the moving speed v are switched before and after. If the moving speed v is difficult to identify, the timing of the change direction is estimated by other methods, such as a change in acceleration in the x direction. The CPU 11 may detect the timing of the change direction by other appropriate methods.

[0048] The CPU 11 determines whether data for one arm swing cycle has been acquired (S5). One arm swing cycle refers to the period from the final arm swing turning timing of the previous cycle to the second turning timing thereafter. If it is determined that data for one cycle has not been acquired (S5; NO), the CPU 11 returns to step S2.

[0049] When it is determined that one cycle's worth of data has been acquired (S5; YES), the CPU 11 performs coordinate conversion on the data in the three axes directions for each data in the cycle, and integrates the y-axis direction component into the x-axis direction component (S6).

[0050] The CPU 11 applies an LPF to the data of one acquired cycle or a number of cycles including the previous cycle, and extracts the stationary R-direction component remaining at each timing, i.e., the gravitational acceleration component (S7). The CPU 11 defines the R direction, the T direction perpendicular thereto, and the angle difference θw for each data of one cycle (S8).

[0051] The CPU 11 calculates the elbow angle θe for each data set using the initially set lengths Lu, Lf and angle difference θw (S9). Processes S8, S9, etc. constitute the specification means of this embodiment. The CPU 11 acquires the median value of the elbow angles θe calculated for each data set for one cycle as a representative value of the elbow angle (S10). The representative value may be an average value as described above. The CPU 11 calculates the radius L using the lengths Lu, Lf and elbow angle θe (S11). As described above, when the lengths Lu and Lf are equal, the CPU 11 may calculate the radius L using the angle difference θw instead of the elbow angle θe.

[0052] The CPU 11 executes an arm swing acceleration calculation process (S12) to be described later. In the arm swing acceleration calculation process, the CPU 11 converts the three-axis acceleration measured at each timing into the RT coordinate system. The CPU 11 sequentially calculates the acceleration gt of the T-axis component of the gravitational acceleration and the moving speed v for each data.

[0053] CPU 11 integrates the movement speed v for each half cycle to calculate the movement amount Lt along the arc (S13). CPU 11 calculates the arm swing angle φ0 for each half cycle from the movement amount Lt and the radius L (S14). CPU 11 may determine the average of the two arm swing angles φ0 as the arm swing angle for that cycle. Alternatively, CPU 11 may calculate the average value of the two movement amounts Lt in step S13 and obtain the arm swing angle for that cycle based on this average value.

[0054] The CPU 11 judges whether the calculated arm swing angle is outside the reference range (S15). When it is judged that the arm swing angle is outside the reference range (S15; YES), the CPU 11 adjusts the arm swing angle (S16). When the arm swing angle is larger than the upper limit of the reference range, the CPU 11 clips the arm swing angle at the upper limit value of the reference range. Since there is no meaning in an arm swing angle that is too large, it is sufficient to output up to a meaningful maximum value. On the other hand, when the arm swing angle is smaller than the lower limit value of the reference range, the CPU 11 sets the arm swing angle to zero. When the arm swing angle is too small, the acceleration is also small, so that the arm swing range cannot usually be calculated with high accuracy. Therefore, when the arm swing angle is calculated to be smaller than the reference, it may be output as not having performed arm swing. Alternatively, in this case, the CPU 11 may output the arm swing angle as an error. That is, it may simply be indicated that the arm swing was not calculated with high accuracy. After that, the processing of the CPU 11 proceeds to processing S17. If it is determined that the arm swing angle is not outside the reference range (S15; NO), the process of the CPU 11 proceeds to step S17.

[0055] In process S17, CPU 11 notifies the obtained arm swing information (S17). Specifically, CPU 11 may, for example, cause display unit 14 to display a graph of the history of arm swing angles. CPU 11 may also determine whether the arm swing angle is within a suitable range and output the determination result. The output may be audio output by notification operation unit 19 in addition to or instead of display output. Alternatively, output by notification operation unit 19 may be performed using a specific vibration pattern or light emission pattern.

[0056] The CPU 11 determines whether or not an operation to end activity measurement has been accepted by the operation acceptance unit 15 (S18). If it is determined that the operation to end activity measurement has not been accepted (S18; NO), the processing of the CPU 11 returns to processing S2. If it is determined that the operation to end activity has been accepted (S18; YES), the CPU 11 ends the index calculation control processing. Before the end, the CPU 11 may write data that needs to be saved from the RAM 12 to the memory 13.

[0057] FIG. 7 is a flowchart showing a control procedure for the arm swing acceleration calculation process executed by the CPU 11 in step S12. The CPU 11 assigns 0 to the variables vp, ap, and t as initial values ​​(S21).

[0058] The CPU 11 acquires the t-th data from the beginning of the three-axis acceleration data for one cycle that was determined to have been acquired in step S5 (S22). The CPU 11 assigns the sum of the variables vp and ap to the moving speed v (S23).

[0059] The CPU 11 performs coordinate conversion on the acquired t-th three-axis acceleration data, and calculates the R-direction component acceleration wr and the T-direction component acceleration wt based on the angle difference θw defined in step S8 (S24). The CPU 11 calculates the acceleration wc related to the stress against the centrifugal force based on the moving speed v and the radius L (S25).

[0060] The CPU 11 subtracts the acceleration wc from the acceleration wr to calculate the acceleration wg of the component of the gravitational acceleration g in the R-axis direction (S26). The CPU 11 calculates the acceleration gt of the component of the gravitational acceleration g in the T-axis direction from the gravitational acceleration g and the acceleration wg, which are constant values ​​(S27). The CPU 11 adds the acceleration wt and the acceleration gt to obtain the acceleration at in the T-axis direction, i.e., the arm swing direction (S28).

[0061] The CPU 11 assigns the moving speed v to a variable vp, assigns the arm swing direction acceleration at to a variable ap, and adds 1 to the variable t (S29). The CPU 11 determines whether or not the three-axis acceleration for one period has been acquired (S30). If it is determined that the three-axis acceleration for one period has not been acquired (S30; NO), the CPU 11 returns to process S22. If it is determined that the three-axis acceleration for one period has been acquired (S30; YES), the CPU 11 ends the arm swing acceleration calculation process and returns the process to the index calculation control process.

[0062] [Variations] The arm swing width may be calculated by the difference in the positions (angles) of the wrist Bw at both ends of the turning points, instead of by integrating (accumulating) the acceleration at of the wrist Bw in the arm swing direction twice. The positions of the turning points may be expressed as angles based on the vertical downward direction.

[0063] FIG. 8 is a diagram for explaining a method of determining the arm swing angle φ0 in a modified example. For example, as mentioned above, the angle φt at a certain time t is φt=cos -1 (wg / g). At the turning point, the arm swing speed v is zero, so the acceleration wc according to the centrifugal force is also zero. Therefore, since wg=wr, we can simply use the acceleration wr, which is the measured value of the component of the gravitational acceleration perpendicular to the arc, to get φt=cos -1 It can be calculated as (wr / g).

[0064] The arm swing angle φ0 is calculated by the sum of the angle φf (first turning point angle) which is the angle φt when the wrist Bw is in the most forward position, and the angle φb (second turning point angle) which is the angle φt when the wrist Bw is in the most rearward position. Note that when the wrist Bw does not move back from the vertical downward position, the angle φb is negative.

[0065] 9 is a flowchart showing the control procedure of the modified index calculation control process by the CPU 11. In this control procedure, steps S12 to S14 in the index calculation control process of the first embodiment are replaced with steps S12a to S14a. Since there are no changes to the other steps, the same reference numerals are used and detailed explanations are omitted.

[0066] After the radius L is calculated in step S11, the CPU 11 determines the acceleration wr at this timing according to the R- and T-axis directions at the front turning point. The CPU 11 calculates the angle φf based on the acceleration wr and the gravitational acceleration g (S12a).

[0067] The CPU 11 specifies the acceleration wr at this timing according to the R- and T-axis directions at the rear turning point. The CPU 11 calculates the angle φb based on the acceleration wr and the gravitational acceleration g (S13a).

[0068] CPU 11 adds angles φf and φb to calculate arm swing angle φ0 (S14a). Then, CPU 11 proceeds to step S15. Each of angles φf and φb can be used as an evaluation index for arm swing. Therefore, CPU 11 may store and retain angles φf and φb as evaluation information together with arm swing angle φ0.

[0069] [Second embodiment] FIG. 10 is a diagram illustrating a sensor configuration according to the second embodiment. In this embodiment, as shown in Fig. 10(a), a user performing an activity is provided with an electronic device 7 fixed to the waist in addition to an electronic device 1 fixed to the arm. The electronic device 7 measures the motion state at the waist position. The electronic device 7 has a three-axis gyro sensor 782 in addition to an acceleration sensor 781.

[0070] FIG. 10(b) is a block diagram showing the functional configuration of the electronic device 7. The electronic device 7 includes a CPU 71, a RAM 72, a memory 73, a display unit 74, an operation receiving unit 75, a communication unit 76, a timing unit 77, a measurement unit 78 (second measurement unit), an announcing operation unit 79, and the like. From these measurements, the vertical direction can be determined using, for example, a Kalman filter.

[0071] The CPU 71 is a processor that performs arithmetic processing and controls the operation of the electronic device 7. The CPU 71 may have a single processor, or may have multiple processors that operate in parallel or independently depending on the application.

[0072] The RAM 72 provides a working memory space for the CPU 71 and stores temporary data. The memory 73 is a non-volatile memory such as a flash memory, and stores programs, setting data, and the like.

[0073] The display unit 74 displays various information and the like under the control of the CPU 71. If the measurement data can basically be viewed on an external device, the display screen of the display unit 74 may be minimal. The display screen is, for example, a liquid crystal display or an organic EL display. The display by the display unit 74 may be in color, or may be limited to a certain number of colors.

[0074] The operation reception unit 75 has a push button switch or the like, and receives an input operation from outside. The operation reception unit 75 may have a touch panel in addition to or instead of the push button switch. The touch panel is located so as to overlap the display screen.

[0075] The communication unit 76 controls communication with an external device. The communication unit 76 can control communication according to a communication protocol such as Bluetooth or wireless LAN. Here, the communication unit 76 can transmit and receive data according to a common protocol that allows communication with the communication unit 16 of the electronic device 1. The communication unit 76 may have a module for communicating via Bluetooth. Alternatively, the communication unit 16 may have a network card for communicating via wireless LAN.

[0076] The time counter 77 counts the passage of time based on a clock signal of a certain frequency generated by an oscillation circuit (not shown) and holds the current time. The time counter 77 may have, for example, an RTC (Real Time Clock). The time counter 77 may also have a logical slowing and fast circuit that adjusts the difference between the oscillation frequency of the oscillation circuit and the passage of time. The time counter 77 may not have a dedicated counter for counting the passage of time, and the CPU 11 may count the output of the logical slowing and fast circuit.

[0077] The measurement unit 78 includes an acceleration sensor 781 and the above-mentioned gyro sensor 782. The acceleration sensor 781 is fixed to the waist and measures three-dimensional acceleration. The gyro sensor 782 is fixed to the waist and measures three-dimensional angular velocity in three orthogonal axial directions.

[0078] The annunciation operation unit 79 performs a predetermined annunciation operation other than displaying on the display screen of the display unit 74. Examples of the annunciation operation include generation of a beep, output of a voice, output of a vibration, and emission or blinking of a light-emitting element. The light-emitting element may be capable of emitting light in a plurality of colors by switching between them. The annunciation operation unit 79 may have some or all of known configurations related to these operations.

[0079] Next, measurement of the arm swing angle will be described. FIG. 11 is a diagram illustrating the acceleration associated with arm swing in this embodiment. As described in the first embodiment, arm swing is represented by a movement along an arc centered on the shoulder Bs. The acceleration associated with arm swing along the arc is given by the sum of the acceleration gt of the T-direction component of the gravitational acceleration g and the acceleration wt corresponding to the arm swing motion due to muscle strength or the like.

[0080] However, in reality, since the user is running or walking, the measured acceleration is further superimposed with an acceleration component (movement acceleration af) corresponding to the movement of the user's body (shoulder Bs). It is difficult to separate this component using the acceleration sensor 181 on the wrist Bw alone.

[0081] The measurement system 100 of this embodiment has an electronic device 7 attached to the waist, separate from the electronic device 1, and detects the movement acceleration af associated with the user's running and walking. The waist is an example of a suitable position where the acceleration component corresponding to the movement of the user's body can be detected, and where the acceleration due to the user's arm swing is not detected. The movement acceleration af measured by the electronic device 7 is, for example, transmitted to the electronic device 1 and integrated with the measurement data of the electronic device 1. Then, the movement acceleration af is subtracted from the acceleration of the T-direction component obtained by the electronic device 1, thereby obtaining a value closer to the acceleration corresponding to the arm swing.

[0082] As described above, since the arm swing acceleration is in a direction along a circular arc, the accelerations wt, gt of the T-axis components and the movement acceleration af do not match depending on the phase of the arm swing, but in this embodiment, the movement acceleration af in the horizontal direction is subtracted as a fixed value. Even with this processing, the accuracy of the measurement value related to the arm swing is improved.

[0083] The calculation of the movement acceleration af by the electronic device 7 may be performed by a conventionally known method. For example, a Kalman filter or the like may be used to identify the vertical direction of the measurement data of the gyro sensor 782, and the movement direction perpendicular to the vertical direction may be identified.

[0084] Note that the time resolution and timing of measurements of the electronic device 1 and the electronic device 7 are usually different. Therefore, the electronic device 7 may perform measurements in synchronization with the measurement of the electronic device 1, or may adjust the measurement result of the electronic device 7 to match the time resolution of the measurement data of the electronic device 1, and then transmit the measurement data to the electronic device 1.

[0085] The electronic device 7 may acquire in advance information on the measurement timing of the electronic device 1. The electronic devices 1 and 7 may each perform synchronized timing measurement according to an accurate date and time using satellite positioning or the like. Alternatively, the electronic device 7 may generate data by linear interpolation or the like so that the measurement data is synchronized with the information on the measurement timing.

[0086] 12 is a flowchart showing a control procedure of the measurement control process executed by the CPU 71 in the electronic device 7. After the process is started, it is continuously and repeatedly performed until an end operation is received.

[0087] The CPU 71 calculates the walking acceleration af from data for an appropriate period (such as a few steps) using known techniques as described above (S71). The period of data to be used may be set by a moving window for the target timing. The CPU 71 synchronizes the timing of the obtained walking acceleration data based on the measurement timing information of the electronic device 1 (S72).

[0088] The CPU 71 causes the communication unit 76 to transmit the walking speed data to the electronic device 1 (S73). In cases where there is a delay in the transmission timing from the measurement, the CPU 71 may attach timing information so that the measurement timing of the output data can be known. Note that the timing information does not need to be attached to all the measurement data.

[0089] The CPU 71 determines whether or not an operation related to a command to end measurement has been received (S74). If it is determined that an operation related to a command to end measurement has not been received (S74; NO), the process of the CPU 71 returns to process S71. If it is determined that an operation related to a command to end measurement has been received (S74; YES), the CPU 71 ends the measurement control process.

[0090] 13 is a flowchart showing the control procedure of the index calculation control process of this embodiment executed by the CPU 11 of the electronic device 1. In this index calculation control process, process S2 of the index calculation control process of the first embodiment is changed to process S2a. In addition, as described later, the contents of the arm swing acceleration calculation process in process S12 are changed. The other processes are the same between both embodiments. The same process contents are given the same reference numerals and detailed explanations are omitted.

[0091] In process S2a, in the loop for each data acquisition, the CPU 11 acquires measurement data from both the acceleration sensor 181 and the gyro sensor 782 (S2a). The data acquisition from the gyro sensor 782 does not have to be simultaneous with the data acquisition timing of the acceleration sensor 181, depending on the data reception timing. After that, the process of the CPU 11 proceeds to process S3.

[0092] 14 is a flowchart showing the control procedure of the arm swing acceleration calculation process that is called in the index calculation control process of the second embodiment and executed by the CPU 11. In this arm swing acceleration calculation process, process S28 in the arm swing acceleration calculation process of the first embodiment is replaced with process S28a. The other processes are the same between the embodiments, and the same process contents are assigned the same reference numerals and the description will be omitted.

[0093] When the acceleration gt of the T-direction component of the gravitational acceleration is calculated in step S27, the CPU 11 calculates the arm swing direction acceleration at by subtracting the above-mentioned movement acceleration af from the sum of the accelerations wt and gt (S28a). Then, the CPU 11 proceeds to step S29.

[0094] As described above, the electronic device 1 of this embodiment includes the CPU 11 that identifies periodic changes related to the user's arm swing from three-dimensional acceleration measured by the measurement unit 18 that measures three-dimensional acceleration. The CPU 11 identifies a two-dimensional plane (RT plane) including the plane of the user's arm swing from the three-dimensional acceleration measured at the user's wrist, and calculates the elbow angle θe by determining the direction of the line segment connecting the wrist Bw and shoulder Bs from the three-dimensional acceleration. In this way, in the acceleration measurement of the wrist Bw, the inclination of the forearm, that is, the average z-axis direction, is determined according to the elbow angle θe during arm swing. On the other hand, since the arm is basically supported against gravity, the acceleration sensor 181 continuously measures the stress against this gravity. Furthermore, since the arm is also supported against the vertical downward component of the centrifugal force accompanying the arm swing, the acceleration sensor 181 periodically detects the stress against this centrifugal force as well. By identifying the directions of these components, the electronic device 1 can easily obtain the relationship between the z-axis direction, which is the average direction of the arm, and the R-axis direction, which is the direction from the wrist Bw to the shoulder Bs, and further the elbow angle θe. In particular, in the electronic device 1, the elbow angle θe is easily obtained only from the measurement value of the acceleration sensor 181. Therefore, the electronic device 1 can more easily identify the elbow angle θe when the user swings his / her arm. In addition, this allows the electronic device 1 to more accurately evaluate the form and posture of the user involved in walking and running.

[0095] The periodic change is a reciprocating motion. Although a person's arm swing is not necessarily accurate or monotonous, treating it as a simple reciprocating motion makes processing easier.

[0096] Further, the CPU 11 specifies the acceleration in a two-dimensional plane (RT plane) based on the three-dimensional acceleration measured during the arm swinging motion. The CPU 11 specifies the direction of the line segment connecting the shoulder Bs and the wrist Bw by extracting a DC component from the acceleration in the two-dimensional plane. The CPU 11 calculates the angle difference θw between this line segment and the direction from the user's wrist Bw to the elbow Be (i.e., the z-axis of the acceleration sensor 181). The CPU 11 calculates the elbow angle θe based on the calculated angle difference θw. The acceleration in the forward and backward directions according to the arm swing periodically inverts and changes with respect to the vertical direction component, so that they are offset in a span of one period or more. Therefore, by extracting the DC component as average data by low-pass filtering or the like of this span, it becomes possible to easily specify the R-axis direction, that is, the direction from the wrist Bw to the shoulder Bs. Furthermore, if the length of the arm is specified, the elbow angle θe can also be specified from the angle difference θw. Through such a procedure, the electronic device 1 can easily obtain the elbow angle from the measurement data of the three-axis acceleration.

[0097] In particular, the CPU 11 calculates the elbow angle θe based on the user's upper arm length Lu and forearm length Lf, and the angle difference θw. In this way, if the arm lengths Lu and Lf are selected, the elbow angle θe can be easily obtained from the angle difference θw. The elbow length can be easily measured by the user. Therefore, the electronic device 1 can easily obtain the elbow angle θe.

[0098] Alternatively, CPU 11 may calculate the elbow angle for each measurement data during one or more cycles of arm swing, and determine a representative value of the elbow angle from the calculated multiple elbow angles. The elbow angle θe is often about the same over a range of several cycles of arm swing, but depending on the habit of arm swing, etc., different values ​​may be obtained locally. Therefore, by determining a representative value for one cycle, electronic device 1 can specify elbow angle θe with higher accuracy.

[0099] Furthermore, electronic device 1 may include a measuring unit 18 that measures three-dimensional acceleration. Electronic device 1 can obtain the amount of arm swing through simple processing based on the acceleration measured by itself, and provide the amount to the user. Therefore, electronic device 1 can provide appropriate arm swing information to the user while reducing the weight of the gyro sensor and other components to reduce the weight.

[0100] Furthermore, the arm swing analysis method of this embodiment identifies periodic changes related to the user's arm swing from three-dimensional acceleration measured by a measurement unit 18 that measures three-dimensional acceleration. This arm swing angle calculation method identifies a two-dimensional plane (RT plane) including the plane of the user's arm swing from the three-dimensional acceleration measured at the user's wrist. The arm swing angle calculation method detects the periodic changes as movement on an arc centered on the user's shoulder Bs within the two-dimensional plane, and calculates the elbow angle θe by determining the direction of the line segment connecting the wrist Bw and shoulder Bs from the three-dimensional acceleration. According to this arm swing analysis method, the relationship between the z-axis direction, which is the direction of the arm, and the R-axis direction, which is the direction from the wrist Bw to the shoulder Bs, and further the elbow angle θe can be easily obtained. Therefore, this arm swing analysis method can more easily specify the state of the user's arm when swinging the arm.

[0101] Moreover, by installing and executing the program 131 of this embodiment on a computer, the elbow angle θe can be easily calculated from the measurement results of the three-dimensional acceleration by the measurement unit 18. Therefore, the program 131 makes it possible to obtain information on the elbow angle θe appropriately at low cost. Furthermore, this enables the computer to more accurately evaluate the user's form, posture, etc. in relation to walking and running.

[0102] The present invention is not limited to the above-described embodiment, but may be modified in various ways. For example, in the above, the elbow angle θe is calculated as a premise for calculating the arm swing angle φ0, but this is not limited to the above. The elbow angle θe may be calculated to obtain an index of another posture related to running, jogging, etc. Alternatively, the elbow angle θe itself may be used as one of the posture indexes.

[0103] In addition, even if the user is swinging his / her arms, there are cases where the user is not moving. For example, the user may be standing still or stepping to check the arm swing form. The CPU 11 may perform a condition determination so that arm swing can be detected even if the user is not running or walking.

[0104] In the above, a representative value of the elbow angle θe for one cycle, for example, a median value, is calculated, but it is not necessary to calculate a representative value of multiple calculated values. The elbow angle θe at a certain point in time may be output as it is. In this case, the certain point in time may be a specific timing in one cycle, for example, a timing when the z-axis is parallel to the vertical direction or a timing of a turn. Alternatively, the certain point in time may be an intermediate timing among all timings for one cycle. In addition, the elbow angle θe may be intermittently calculated from a portion of multiple measurement data, and the average value thereof may be used as the representative value.

[0105] Furthermore, when extracting a DC component from one period of acceleration, the LPF does not have to be used as described above, and any other method may be used.

[0106] In the above, the lengths Lu and Lf of the upper arm and forearm are determined according to height. It has also been described that age, sex, race, weight, foot size, etc. may also be taken into consideration. In contrast, these lengths may be roughly categorized based on some or all of age, sex, race, weight, foot size, etc. without taking height into consideration. Alternatively, more simply, the lengths Lu and Lf of the upper arm and forearm may be treated as constants.

[0107] In the modification of the first embodiment, the inclination of the line segment connecting the shoulder Bs and the wrist Bw from the vertical direction may be obtained by other methods instead of by the gravitational acceleration.

[0108] Furthermore, the electronic device 1 may only perform a minimum display. Except for the notification by the notification operation unit 19, detailed graphs, history, and the like may be displayed only on the external electronic device 4.

[0109] Moreover, the electronic device 1 has a shape of an electronic wristwatch, but is not limited to this. For example, the electronic device 1 may be a simple belt-like device. Also, as long as the electronic device 1 is fixed to the wrist, it does not have to be fixed by a band that goes around the arm.

[0110] Furthermore, the analysis of the arm swing and the notification operation do not have to be performed by the electronic device 1. The measurement data and some or all of the analysis data may be sent to the electronic device 4, and the remaining analysis and notification operation may be performed by the electronic device 4.

[0111] Furthermore, the electronic device 1 may have a configuration as a processing unit and a configuration as a measuring unit that are separate from each other. That is, an acceleration sensor may be attached externally to the control device.

[0112] Furthermore, the electronic device 7 is not limited to being worn on the waist, so long as it is somewhere other than the arm (other than the hand side of the shoulder). In this case, the electronic device 7 is preferably worn as close to the trunk as possible, or on the legs which are more susceptible to the effects of contact with the ground.

[0113] In the above description, the memory 13 consisting of a non-volatile memory such as a flash memory is taken as an example of a computer-readable medium for storing the program 131 related to the arm swing index calculation control of the present invention, but is not limited to this. As other computer-readable media, other non-volatile memories such as MRAM, HDDs, or portable recording media such as CD-ROMs and DVD disks can be applied. In addition, a carrier wave is also applied to the present invention as a medium for providing data of the program according to the present invention via a communication line. In addition, the specific configurations, contents and procedures of the processing operations, etc. shown in the above embodiments can be modified as appropriate without departing from the spirit of the present invention. The scope of the present invention includes the scope of the invention described in the claims and its equivalents. [Explanation of symbols]

[0114] 1, 4, 7 Electronic equipment 11 CPU 12 RAM 13. Memory 131 Programs 14 Display section 15 Operation reception section 16 Communications Department 17 Timing section 18 Measurement section 181 Acceleration Sensor 19. Notification section 71 CPU 72 RAM 73 Memory 74 Display section 75 Operation reception section 76 Communications Department 77 Timekeeping section 78 Measurement section 781 Acceleration Sensor 782 Gyro Sensor 79 Notification section 100 Measurement System Be Elbow Bs shoulder Bw wrist L radius af Movement acceleration at Arm swing direction acceleration v Movement speed θe Elbow angle θw Angle difference φ0 Arm swing angle

Claims

1. a processing unit for identifying a periodic change associated with a user's arm swing from the three-dimensional acceleration measured by a measuring unit that measures the three-dimensional acceleration, The processing unit defines a two-dimensional plane including a plane of the user's arm swing from the three-dimensional acceleration measured at the user's wrist, detects the periodic change as a movement on an arc centered on the user's shoulder within the two-dimensional plane, and calculates an elbow bending angle by determining a direction of a line segment connecting the wrist and the shoulder from the three-dimensional acceleration. electronic equipment.

2. The electronic device according to claim 1 , wherein the motion is a reciprocating motion.

3. The processing unit specifies an acceleration in the two-dimensional plane based on the three-dimensional acceleration measured during an arm swing motion, extracting a direct current component from the acceleration in the two-dimensional plane to identify a direction of the line segment; Calculating a first angle between the line segment and a direction from the wrist to the elbow of the user; Calculating a bending angle of the elbow based on the calculated first angle.

3. The electronic device according to claim 2.

4. The electronic device according to claim 3 , wherein the processing unit calculates a bending angle of the elbow based on a length of the arm of the user and the first angle.

5. 2. The electronic device according to claim 1, wherein the processing unit calculates an elbow bending angle for each piece of measurement data during one or more cycles of the arm swing, and determines a representative value of the elbow bending angle from the calculated multiple elbow bending angles.

6. 6. The electronic device according to claim 1, further comprising a measurement unit that measures the three-dimensional acceleration.

7. An arm swing angle calculation method for identifying a periodic change related to a user's arm swing from a three-dimensional acceleration measured by a measurement unit that measures three-dimensional acceleration, comprising: A two-dimensional plane including the plane of the user's arm swing is defined from the three-dimensional acceleration measured at the user's wrist, the periodic change is detected within the two-dimensional plane as a movement on an arc centered on the user's shoulder, and the bending angle of the elbow is calculated by determining the direction of a line segment connecting the wrist and the shoulder from the three-dimensional acceleration. Arm swing analysis method.

8. Computer, functioning as an identification means for identifying a periodic change associated with the user's arm swing from the three-dimensional acceleration measured by a measurement unit that measures the three-dimensional acceleration; The identification means is A two-dimensional plane including the plane of the user's arm swing is defined from the three-dimensional acceleration measured at the user's wrist, the periodic change is detected within the two-dimensional plane as a movement on an arc centered on the user's shoulder, and the bending angle of the elbow is calculated by determining the direction of a line segment connecting the wrist and the shoulder from the three-dimensional acceleration. program.

Images