Arm swing determination method, electric device, and program

Abstract

To provide an arm swing determination method capable of more appropriately determining an arm swing state, an electric device, and a program.SOLUTION: An arm swing determination method includes: acquiring an arm swing cycle of a user from a first acceleration in three orthogonal axial directions measured by a first sensor mounted to a wrist of the user (S5); acquiring a grounding cycle related to running or walking of the user from a second acceleration and an angular velocity measured by a second sensor mounted to a part other than the arms of the user (S6); and determining that arm swing of the user is not appropriately obtained when a difference between the arm swing cycle and the grounding cycle is outside of a reference (S7, S10).SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention relates to an arm swing determination method, an electronic device, and a program. [Background technology]

[0002] Conventionally, there are technologies that support activities such as running, walking, etc. From acceleration and angular velocity measured by physical sensors, the number of steps taken while running or walking, the time interval per step, the achievement rate of these goals, posture and its shaking, arm swing state, etc. can be obtained.

[0003] The sensor or an electronic device including the sensor is attached to the user's body. By attaching the electronic device to the waist or the like, the movement of the trunk can be reliably obtained. In Patent Document 1, a sensor device attached near the center line of the human body, such as the waist, more reliably determines when the user lands. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-006371 A Summary of the Invention [Problem to be solved by the invention]

[0005] On the other hand, measuring arm swing is preferably performed using the arm itself, but there is a problem in that measurement of arm swing using the arm itself often results in erroneous recognition when the swing width of the arm is small.

[0006] An object of the present invention is to provide an arm swing determination method, electronic device, and program that can more appropriately determine the arm swing state. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention provides acquiring an arm swing period of the user from a first acceleration in three orthogonal axial directions measured by a first sensor attached to the wrist of the user; A ground contact period associated with running and walking of the user is obtained from a second acceleration and an angular velocity measured by a second sensor attached to a part other than the arm of the user; When the difference between the arm swing period and the ground contact period is not within a standard, it is determined that the arm swing of the user is not properly obtained. This is a method for determining arm swing. Effect of the Invention

[0008] According to the present invention, it is possible to more appropriately determine the arm swing state. [Brief description of the drawings]

[0009] [Figure 1] 1 is a diagram showing an overall configuration of a measurement system according to an embodiment of the present invention; [Diagram 2] 1 shows a state in which electronic devices and a sensor device are worn on the body. [Diagram 3] FIG. 2 is a block diagram showing functional configurations of the electronic device and the sensor device. [Figure 4] FIG. 2 is a block diagram showing a functional configuration of the electronic device. [Diagram 5] FIG. 2 is a diagram illustrating a measurement by an acceleration sensor. [Figure 6] 10A and 10B are diagrams illustrating measurement of arm swing and calculation of the magnitude of arm swing. [Figure 7] FIG. 13 is a diagram showing an example of a change in acceleration over time at the waist position. [Figure 8] 10 is a flowchart showing a control procedure of a ground contact identification process executed by the sensor device. [Figure 9] 13 is a flowchart showing a control procedure of an index notification control process executed in the electronic device 1. [Figure 10] 10 is a flowchart showing a control procedure for an arm swing amount calculation process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing the overall configuration of a measurement system 100 of this embodiment. The measurement system 100 includes electronic devices 1 and 4 and a sensor device 7 .

[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] The sensor device 7 is attached to the user's waist and measures the user's motion state. The sensor device 7 is capable of processing the measurement data. However, as long as it is capable of communicating with the electronic device 4, the sensor device 7 may basically be a device specialized for a sensor function.

[0013] The electronic device 4 is a terminal device (computer) such as a smartphone, but may be a general-purpose electronic calculator (computer), etc. The electronic device 1, the sensor device 7, 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, the sensor device 7, and the electronic device 4 do not necessarily need to be constantly connected during an activity. However, in the following description, the electronic device 4 is assumed to be communicatively connected to the electronic device 1 and the sensor device 7 during an activity.

[0014] FIG. 2 shows a state in which the electronic device 1 and the sensor device 7 are worn on the body.

[0015] As described above, the electronic device 1 is worn on the wrist. The sensor device 7 is worn on the waist. Since the sensor device 7 acquires acceleration in the direction of gravity and the direction of travel as described below, the sensor device 7 may be configured to acquire only acceleration in the above two axial directions by being worn accurately.

[0016] When the electronic device 4 is carried together, it is held so as not to interfere with the measurement of arm swing by the electronic device 1 and the measurement of waist movement by the sensor device 7.

[0017] FIG. 3 is a block diagram showing the functional configuration of the electronic device 1 and the sensor device 7. As shown in FIG. As shown in FIG. 3(a), an electronic device 1 such as an electronic wristwatch includes a CPU 11 (Central Processing Unit) and a RAM 12 (Random Access Memory) (collectively referred to as a control unit), a memory 13, a display unit 14, an operation reception unit 15, a communication unit 16, a timing unit 17, a measurement unit 18 (first sensor), and an alarm operation unit 19.

[0018] 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.

[0019] The RAM 12 provides a working memory space for the CPU 11. The RAM 12 stores temporary data.

[0020] 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. The CPU 11, the RAM 12, and the memory 13 are at least included in the configuration of a computer when the electronic device 1 executes an indicator notification control process described later.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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 time, and the CPU 11 may count the output of the logical slowing and fast circuit.

[0025] The measurement unit 18 has an acceleration sensor 181. The acceleration sensor 181 measures acceleration (first acceleration) in three orthogonal axial directions.

[0026] 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.

[0027] As shown in FIG. 3(b), the sensor device 7 includes a CPU 71, a RAM 72, a memory 73, an operation receiving unit 75, a communication unit 76, a timing unit 77, a measurement unit 78 (second sensor), and an alarm operation unit 79. From these measurements, the vertical direction can be determined using, for example, a Kalman filter.

[0028] The CPU 71 is a processor that performs arithmetic processing and controls the operation of the sensor 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.

[0029] 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.

[0030] The operation reception unit 75 has a push button switch or the like, and receives an input operation from outside. The push button switch may be, for example, a switch that alternately switches between on and off of power supply and between starting and ending measurement in response to a push operation.

[0031] 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.

[0032] The clock unit 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 clock unit 77 may have, for example, an RTC (Real Time Clock). The clock unit 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 clock unit 77 may not have a dedicated counter for counting time, and the CPU 11 may count the output of the logical slowing and fast circuit.

[0033] The measuring unit 78 has an acceleration sensor 781, the above-mentioned angular velocity sensor 782, etc. The acceleration sensor 781 is fixed to the waist, particularly to the center of the back side of the user's waist, and measures two-dimensional or three-dimensional acceleration (second acceleration) including the direction of gravity and the forward direction of the body (travel direction). The angular velocity sensor 782 is fixed to the waist and measures three-dimensional angular velocity in three orthogonal axial directions. The annunciation operation unit 79 performs a predetermined annunciation operation. 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.

[0034] FIG. 4 is a block diagram showing the functional configuration of the electronic device 4. The electronic device 4, such as a smartphone, includes a CPU 41, a RAM 42, a memory 43, a display unit 44, an operation receiving unit 45, a communication unit 46, a timer unit 47, an announcing operation unit 49, and the like.

[0035] The CPU 41 is a processor that performs arithmetic processing. The CPU 41 performs arithmetic processing and generally controls the operation of the electronic device 4. The CPU 41 may have a single processor, or may have multiple processors that perform calculations in parallel or operate separately depending on the application.

[0036] The RAM 42 provides a working memory space for the CPU 41. The RAM 42 stores temporary data. As described later, the CPU 41 and the RAM 42 may constitute a control unit of the present embodiment.

[0037] The memory 43 is, for example, a non-volatile memory such as a flash memory or a hard disk drive (HDD). The memory 43 stores a program 431, setting data, measurement history data, and the like. The program 431 controls the execution of data processing and analysis of the activity measurement described below. In particular, the program 431 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.

[0038] The display unit 44 displays various information under the control of the CPU 41. The display unit 44 has a display screen such as a liquid crystal display or an organic EL display.

[0039] The operation reception unit 45 has a push button switch, a touch panel, etc., and receives input operations from outside. The touch panel is positioned so as to overlap the display screen.

[0040] The communication unit 46 controls communication with external devices. The communication unit 46 can control communication according to a communication protocol such as Bluetooth or wireless LAN as described above. The communication unit 46 may have a module for performing communication via Bluetooth. Alternatively, the communication unit 46 may have a network card for performing communication via wireless LAN.

[0041] The time counter 47 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 47 may have, for example, an RTC (Real Time Clock). The time counter 47 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 47 may not have a dedicated counter for counting the passage of time, and the CPU 41 may count the output of the logical slowing and fast circuit.

[0042] The annunciation operation unit 49 performs a predetermined annunciation operation other than displaying on the display screen of the display unit 44. 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 49 may have some or all of known components related to these operations.

[0043] The electronic device 4 may have a configuration required for various functions that can be provided as a general-purpose electronic device.

[0044] Next, the operation of the acceleration sensor 181 will be described. FIG. 5 is a diagram for explaining the measurement by the acceleration sensor 181. As shown in FIG. As shown in FIG. 5(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 user's wrist, 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 user's wrist to the elbow. 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 hand turning motion described later.

[0045] 5(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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] Next, measurement of arm swing will be described. Fig. 6 is a diagram for explaining measurement of arm swing and calculation of the magnitude of arm swing. Here, the position of the shoulder Bs is shown as fixed. Therefore, Fig. 6 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 FIG. 6 is the angle of the arm swing (magnitude of the arm swing).

[0050] 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 this, 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 between the RT axis and the xz axis depends on the elbow angle θe of the elbow bending angle, 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 described above, accelerations wg and wc according to 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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).

[0057] 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.

[0058] 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.

[0059] 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)).

[0060] 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).

[0061] 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 adjacent 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 variations 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.

[0062] 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.

[0063] As described above, the accuracy of the magnitude of the arm swing depends on the accuracy of the turning point of the arm swing. If the arm swing is small, the acceleration related to the arm swing is also small and the change is likely to be irregular, making it difficult to identify the turning point. If the accumulation of the arm swing magnitude continues without identifying the turning point, an arm swing that is actually small may be accumulated multiple times and erroneously evaluated as a large arm swing.

[0064] Such a small arm swing is difficult to identify using only the acceleration sensor 181 that measures with the arm. On the other hand, the period of the arm swing is approximately equal to the period of running and walking, that is, twice the period when the foot touches the ground (lands) (two steps). The measurement system 100 and arm swing determination method of this embodiment determine whether the arm swing period obtained is approximately twice the foot ground contact period based on the measurement by the measurement unit 78. If the difference between the arm swing period and the ground contact period is outside the standard, it is determined that the arm swing is small and the identification is inaccurate, that is, the arm swing result is not obtained properly.

[0065] Fig. 7 is a diagram showing an example of the change over time in acceleration at the waist position obtained by the acceleration sensor 781 of the measurement unit 78. Fig. 7(a) shows the change over time in the vertical component Ax of the acceleration. Fig. 7(b) shows the change over time in the component Ay of the acceleration in the user's traveling direction.

[0066] The vertical direction can be specified based on the gravitational acceleration in the same manner as above. If the sensor device 7 is attached properly and the user is running straight without any shaking of the trunk, the acceleration sensor 781 measures the acceleration in a plane including the vertical direction and the traveling direction. During actual running, the traveling direction changes depending on the shaking of the trunk, the curve of the running course, the detour of oncoming people, etc., and therefore the acceleration of the component perpendicular to the traveling direction and the gravitational acceleration direction may also be mixed in depending on the rotational movement of the waist (trunk). Therefore, the traveling direction component of the acceleration is obtained by correcting the deviation in the rotational direction by the angular velocity sensor 782 in the plane (horizontal plane) perpendicular to the gravitational acceleration component.

[0067] As shown in Figure 7(a), the position of the hips moves simply up and down when running or walking. The presence or absence of running or walking is determined when this amplitude exceeds a reference value th1. After exceeding the reference value th1 at time t0, the timing t1 of the first maximum in vertical acceleration corresponds to the state immediately after the leg leaves the ground (takes off).

[0068] As shown in Fig. 7(b), the forward acceleration during running and walking changes twice, one large value and one small value, during one up and down movement in the vertical direction. Of these, the minimum value just before takeoff is due to the decrease in acceleration when landing. Therefore, when the measurement system 100 detects a maximum in the vertical acceleration, it can obtain the landing timing by identifying the timing t2 at which the forward acceleration becomes minimum just before the timing t1.

[0069] The time between these landing timings is the time required per step. The landing interval may be an average time required for several steps before and after, or several seconds. The landing timing and the timing of the turning point of the arm swing do not match. That is, there is a phase difference between the arm swing and the leg movement. Therefore, it is not necessary to strictly match the detection timing of the two. However, it is preferable to match the time of one of the timekeeping units 17 and 77 with the time of the other in advance. Alternatively, the electronic device 1 and the sensor device 7 may each obtain the accurate date and time by satellite positioning or from the electronic device 4, and adjust the time to be counted. For this purpose, the electronic device 1 and the sensor device 7 may be provided with a satellite radio wave receiving module (not shown) and may receive radio waves from a positioning satellite to obtain the date and time.

[0070] 8 is a flowchart showing a control procedure of the ground contact identification process executed by the CPU 71 of the sensor device 7. This process is continuously executed from the start of the measurement operation of the sensor device 7 until the end of the measurement operation.

[0071] The CPU 71 acquires measurement data (S71). The CPU 71 determines whether the user is running or walking based on the amplitude and frequency of the acceleration change (S72). The CPU 71 determines whether the user is running or walking (S73). If it is determined that the user is not running or walking (S73; NO), the CPU 71 returns to process S71.

[0072] When it is determined that the user is running or walking (S73; YES), the CPU 71 identifies the timing t1 at which the vertical component of the acceleration (Ax) reached a maximum value after the timing t0 at which the acceleration exceeded a reference value (S74). The CPU 71 traces the acceleration's forward component (Ay) back from the timing t1 to identify the timing t2 at which the acceleration reached a minimum value (S75). The CPU 71 outputs information about the timing t2 to the outside via the communication unit 76 (S76). The output destination is the electronic device 1 or the electronic device 4.

[0073] The CPU 71 determines whether or not an operation to end the measurement has been accepted (S77). If it is determined that an operation to end the measurement has not been accepted (S77; NO), the CPU 71 returns to the process S71. If it is determined that an operation to end the measurement has been accepted (S77; YES), the CPU 71 ends the ground contact identification process. The sensor device 7 may directly transmit and output the data acquired in step S71 to the electronic device 4. In this case, the electronic device 4 may execute steps S72 and onward.

[0074] 9 is a flowchart showing a control procedure of an indicator notification control process by the CPU 11 in the electronic device 1. This process related to the arm swing determination method of the present embodiment is started upon a start command from an application / software related to the measurement of a walking or running activity, for example, and is repeatedly executed continuously until an end command is received.

[0075] 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.

[0076] 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.

[0077] 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).

[0078] If it is determined that the person is not running or walking (S3; NO), the CPU 11 proceeds to step S14. 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.

[0079] The CPU 11 calculates the arm swing period Ta as the interval between the most recent turning timing (first turning timing) among the timings of turning of the arm swing detected in the process S4 and the timing detected two times before that (second turning timing) (S5; first acquisition means). The CPU 11 acquires the timing t2 from the outside (the sensor device 7 or the electronic device 4) by the communication unit 16, and acquires the ground contact period Tf based on the interval of the timing t2 (S6; second acquisition means). The CPU 11 determines whether the arm swing period Ta is within a reference range based on the ground contact period Tf (S7). The reference range is not particularly limited, but is determined by, for example, multiplying twice the ground contact period Tf by a coefficient k1 less than 1 and multiplying twice the ground contact period Tf by a coefficient k2 greater than 1. The coefficients k1 and k2 are, for example, 0.8 and 1.2 (i.e., 1.6 times or more and 2.4 times or less of the ground contact period Tf) as a range of 20%, but are not limited thereto. The upper width and the lower width may be determined to have different sizes (ratio widths) with respect to the ground contact period Tf.

[0080] If it is determined that the arm swing period Ta is not within the reference range from the ground contact period Tf (S7; NO), the CPU 11 determines that the result of the arm swing is not appropriate, i.e., that the user's arm swing is not obtained appropriately, and sets the magnitude of the arm swing to "0" (S10). Alternatively, instead of setting the magnitude of the arm swing to "0", the CPU 11 may output an error (invalid) as the magnitude of the arm swing. Processes S7 and S10 constitute the determination means of the program 131 of this embodiment. Then, the process of the CPU 11 proceeds to process S13.

[0081] When it is determined that the arm swing period Ta is within the reference range from the ground contact period Tf (S7; YES), the CPU 11 determines that the arm is being swung (S8). The CPU 11 executes an arm swing amount calculation process (S9) 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.

[0082] If it is determined in process S9 that the magnitude of the arm swing is outside the reference range (S11; YES), CPU 11 adjusts (clips) the magnitude of the arm swing (S12). If the magnitude of the arm swing is greater than the upper limit of the reference range, CPU 11 sets the magnitude of the arm swing to the upper limit value of the reference range. If the magnitude of the arm swing is less than the lower limit of the reference range, CPU 11 sets the magnitude of the arm swing to zero. CPU 11 processing proceeds to process S13. If it is determined in process S9 that the magnitude of the arm swing is not outside the reference range (S11; NO), CPU 11 processing proceeds to process S13.

[0083] CPU 11 causes display unit 14 and / or notification unit 19 to output information about the arm swing (S13). For example, when the magnitude of the arm swing is not within a suitable range, CPU 11 may cause notification unit 19 to perform a notification operation such as audio output that the arm swing is small or large (does not meet the standard). CPU 11 may, for example, cause display unit 14 to display a graph of the change over time (history) of the magnitude of the arm swing. Even when the magnitude of the arm swing is appropriate, a notification operation indicating that the magnitude is appropriate may be performed at appropriate intervals or only once after the start of the activity. The notification operation may be performed in combination with a light emitting signal, vibration, or the like. Alternatively, the content of the notification operation may be determined by a vibration pattern.

[0084] The CPU 11 determines whether or not an operation to end the process related to the activity measurement has been accepted (S14). If it is determined that the end operation has not been accepted (S14; NO), the process of the CPU 11 returns to process S2. If it is determined that the end operation has been accepted (S14; YES), the CPU 11 ends the indicator notification control process.

[0085] FIG. 10 is a flowchart showing the control procedure for the arm swing amount calculation process executed in step S9 above.

[0086] The CPU 11 performs coordinate conversion on the data in the three axial directions for each data item within the period, and integrates the y-axis direction component into the x-axis direction component (S21).

[0087] The CPU 11 applies the LPF to the data of one acquired cycle or a plurality of cycles including the previous cycle. The CPU 11 extracts the stationary R-direction component remaining at each timing, i.e., the gravitational acceleration component (S22). The CPU 11 defines the R-direction and the T-direction perpendicular thereto, and the angle difference θw for each data of one cycle (S23).

[0088] The CPU 11 calculates the elbow angle θe for each data item using the initially set lengths Lu, Lf and angle difference θw (S24). The CPU 11 acquires the median value of the elbow angles θe calculated for each data item for one cycle as a representative value of the elbow angle (S25). 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 (S26). 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.

[0089] The CPU 11 assigns 0 to the variables vp, ap, and t as initial values ​​(S27).

[0090] 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 (S28). The CPU 11 assigns the sum of the variables vp and ap to the moving speed v (S29).

[0091] The CPU 11 performs coordinate conversion on the acquired t-th triaxial acceleration data based on the angle difference θw defined in step S23, and calculates the acceleration wr of the R-direction component and the acceleration wt of the T-direction component (S30). 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 (S31).

[0092] 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 (S32). 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 ​​(S33). 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 (S34).

[0093] 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 (S35). The CPU 11 determines whether or not the three-axis acceleration for one period has been acquired (S36). If it is determined that the three-axis acceleration for one period has not been acquired (S36; NO), the process of the CPU 11 returns to step S28.

[0094] When it is determined that all three-axis accelerations for one period have been acquired (S36; YES), the CPU 11 converts the three-axis accelerations measured at each timing into the RT coordinate system. The CPU 11 calculates the acceleration gt of the T-axis component of the gravitational acceleration and the moving speed v for each data item in sequence.

[0095] CPU 11 integrates the movement speed v for each half cycle to calculate the movement amount Lt along the arc (S37). CPU 11 calculates the arm swing angle φ0 for each half cycle from the movement amount Lt and the radius L (S38). CPU 11 may take the average of the two arm swing angles φ0 as the arm swing angle for that cycle (the magnitude of the arm swing). Alternatively, CPU 11 may calculate the average value of the two movement amounts Lt in process S37 and determine the arm swing angle for this cycle based on this average value. CPU 11 ends the arm swing amount calculation process and returns the process to the index notification control process.

[0096] The electronic device 1 may transmit and output the data acquired in process S2 directly to the electronic device 4. All other processes may be performed by the electronic device 4. As described above, when the measurement data of the sensor device 7 is also transmitted and output to the electronic device 4, the electronic device 4 (CPU 41) may centrally process all data. The centralized data processing may be controlled based on the program 431.

[0097] As described above, the arm swing determination method by the measurement system 100 of this embodiment is executed in the following procedure. (1) The user's arm swing period Ta is obtained from the first acceleration in three orthogonal axial directions measured by the measurement unit 18 attached to the user's wrist. (2) The ground contact period Tf related to the user's running and walking is obtained from the second acceleration and angular velocity measured by the measurement unit 78 attached to a part other than the user's arm (such as the waist). (3) If the difference between the arm swing period Ta and the ground contact period Tf does not fall within the standard, it is determined that the user's arm swing is not properly obtained. This arm swing determination method does not calculate an inaccurate arm swing magnitude when the turning point cannot be accurately identified, for example when the arm swing is small. Therefore, an erroneous arm swing evaluation is prevented from being presented to the user. In particular, when the arm swing magnitude is calculated by integrating the moving speed between turning points, if the turning point is overlooked, the magnitude of the arm swing, which is actually small, is overestimated. According to this embodiment, such overestimation can be prevented and the arm swing state can be more appropriately determined.

[0098] The arm swing determination method of this embodiment includes the following steps: (4) Identifying an acceleration component along the arm swing direction obtained from a measurement value of wrist acceleration. (5) Identifying a turning point where the arm swing direction changes based on this acceleration component. (6) Calculating the interval between a first turning timing and a second turning timing two times before the first turning timing as an arm swing period. In this way, by directly identifying both ends of the arm swing, it is possible to obtain an appropriate arm swing period according to the variations in the user's arm swing and ground contact.

[0099] Furthermore, the arm swing determination method of this embodiment includes the following procedure: (7) The swing width is obtained by integrating the acceleration components along the arm swing direction (in the T-axis direction) between adjacent turning points. In this way, the magnitude of the arm swing can be easily obtained by integrating (accumulating) the acceleration component twice along the arm movement direction. However, with this method, if the turning point is not identified, the magnitude of the arm swing will be overestimated. Therefore, according to the present invention, when the arm swing is small and the turning point is unclear, the magnitude of the arm swing is less likely to be overestimated.

[0100] In addition, the arm swing determination method may set the magnitude of the arm swing to zero when it is determined that the arm swing is not properly obtained. This makes it possible to reduce arm swing evaluations with inaccurate swing widths. In particular, it is possible to prevent the arm swing from being overestimated.

[0101] Furthermore, when it is determined that the arm swing is not appropriate, this arm swing judgment method performs a notification operation to indicate that the arm swing does not meet the criteria. By notifying the user that the arm swing is not appropriate, the user can quickly learn that the arm swing is not appropriate and can make improvements as necessary.

[0102] Moreover, it is preferable that the measuring unit 78 is attached to the waist. By measuring at a position close to the trunk, the running or walking of the human body can be easily identified. As a result, the landing cycle can be more appropriately identified in this arm swing determination method.

[0103] The electronic device 1 of this embodiment also includes a CPU 11. The CPU 11 acquires the user's arm swing period Ta from the acceleration in three axial directions measured by a measurement unit 18 attached to the user's wrist. The CPU 11 acquires a ground contact period Tf related to the user's running and walking, which is obtained from the acceleration and angular velocity measured by a measurement unit 78 attached to a part other than the user's arm. If the difference between the arm swing period Ta and the ground contact period Tf is outside the standard, the CPU 11 determines that the user's arm swing is not properly obtained. In this way, the electronic device 1 judges whether the arm swing measured by itself is appropriate based on the landing period obtained by the sensor device 7. The electronic device 1 worn on the arm is easy to measure and has high versatility in terms of device use, but it also has some difficulties in measurement. By measuring and acquiring the landing period, which is closely related to running and walking and has almost the same length as the arm swing period, on a part other than the arm, the electronic device 1 can more appropriately determine the arm swing state.

[0104] Furthermore, by installing and executing the programs 131 and 431 of the present embodiment on a computer, it becomes possible to easily and appropriately determine and evaluate the arm swing state with greater accuracy.

[0105] The present invention is not limited to the above-described embodiment, but may be modified in various ways. For example, the arm swing period Ta and the ground contact period Tf may be specified by the average of multiple periods, rather than the length of each period. In particular, the arm swing period Ta is often mixed with unusual actions such as the user looking at the electronic device 1, wiping sweat, or drinking water. Therefore, by averaging multiple periods, it is possible to prevent an abnormality from being notified every time such actions occur in a short period of time.

[0106] In the above, the validity of the arm swing period is determined within a range of a predetermined ratio to the landing period, but this is not limiting.

[0107] Also, the notification action related to the arm swing state does not necessarily have to be performed. Whether or not to perform the notification action, and the frequency of performing the notification action, etc. may be determined by the setting operation received by the operation receiving unit 15, 45. Similarly, the type of notification action, for example, whether or not to perform audio output in addition to display output, etc. may also be switched by the setting.

[0108] Furthermore, the sensor device 7 is not limited to being attached to the waist, so long as it is attached to a part other than the arm (other than the hand side of the shoulder). In this case, the sensor device 7 is preferably attached to a position as close to the trunk as possible, or to the leg which is more susceptible to the effects of contact with the ground.

[0109] In the above embodiment, the magnitude of the arm swing is calculated by integrating the acceleration along the direction of the arm swing, but this is not limiting and the magnitude of the arm swing may be calculated by other methods.

[0110] In the above description, the memory 13 (43) consisting of a non-volatile memory such as an HDD or a flash memory is used as an example of a computer-readable medium for storing the program 131 (431) related to the index notification control of the present invention, but the present invention is not limited to this. As other computer-readable media, other non-volatile memories such as MRAM and portable recording media such as CD-ROMs and DVD disks can be applied. Furthermore, a carrier wave is also applied to the present invention as a medium for providing data of the program related 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]

[0111] 1, 4 Electronic equipment 7 Sensor device 11, 41, 71 CPUs 12, 42, 72 RAM 13, 43, 73 Memory 131, 431 Program 14, 44 Display section 15, 45, 75 Operation reception area 16, 46, 76 Communications Department 17, 47, 77 Timing section 18, 78 Measurement section 181, 781 Acceleration sensor 782 Angular Rate Sensor 19, 49, 79 Notification section 100 Measurement System Be Elbow Bs shoulder Bw wrist Ta arm swing cycle Tf grounding period

Claims

1. acquiring an arm swing period of the user from a first acceleration in three orthogonal axial directions measured by a first sensor attached to the wrist of the user; A ground contact period associated with running and walking of the user is obtained from a second acceleration and an angular velocity measured by a second sensor attached to a part other than the arm of the user; When the difference between the arm swing period and the ground contact period is not within a standard, it is determined that the arm swing of the user is not properly obtained. Arm swing determination method.

2. Identifying an acceleration component along an arm swing direction obtained from the measurement value of the first acceleration; Identifying a turning point at which the direction of the arm swing is changed based on an acceleration component along the arm swing direction; An interval between a first turning timing and a second turning timing two times before the first turning timing is calculated as an arm swing period. The arm swing determination method according to claim 1.

3. The magnitude of the arm swing is calculated by integrating the acceleration components along the arm swing direction between the adjacent turning points. The arm swing determination method according to claim 2.

4. If it is determined that the user's arm swing is not properly obtained, the magnitude of the arm swing is set to zero. The arm swing determination method according to claim 1.

5. When it is determined that the arm swing of the user is not properly obtained, a notification operation is performed to indicate that the arm swing of the user does not satisfy the criterion. The arm swing determination method according to claim 1.

6. The arm swing determination method according to claim 1 , wherein the second sensor is attached to a waist.

7. acquiring an arm swing period of the user from a first acceleration in three axial directions measured by a first sensor attached to the wrist of the user; A ground contact period related to the running and walking of the user is obtained from a second acceleration and an angular velocity measured by a second sensor attached to a part other than the arm of the user; and When the difference between the arm swing period and the ground contact period is not within a standard, it is determined that the arm swing of the user is not properly obtained. A control unit is provided. electronic equipment.

8. Computer, a first acquisition means for acquiring an arm swing period of the user calculated from a first acceleration in three axial directions measured by a first sensor attached to the wrist of the user; a second acquisition means for acquiring a ground contact period related to the running and walking of the user, the ground contact period being calculated from a second acceleration and an angular velocity measured by a second sensor attached to a part of the user other than the arm; a determination means for determining that the user's arm swing is not properly obtained when the difference between the arm swing period and the ground contact period is not within a standard range; A program that functions as a

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