JP2012185809A - Electronic apparatus, sampling cycle determination method, and sampling cycle determination program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of wasting electric power due to sampling of an acceleration signal at a fixed cycle after detecting walking vibration in conventional practice.SOLUTION: An acceleration signal associated with the movement of a user is sampled by an acceleration detection part (S201), a cycle of the acceleration signal is calculated in a signal cycle calculation part (S202), and a sampling cycle for the sampling is determined in a sampling cycle determination part on the basis of the cycle of the acceleration signal (S203). As a result, the sampling cycle is determined on the basis of the acceleration signal detected by walking, whereby waste of electric power caused regardless of walking pitch can be avoided.

Description

  The present invention relates to an electronic device, a sampling cycle determination method, and a sampling cycle determination program.

Conventionally, there has been a pedometer that includes an acceleration sensor that detects acceleration caused by walking. This pedometer measures the number of vibrations associated with walking as the number of steps. Here, the acceleration sensor of the pedometer detects the acceleration signal at a constant sampling period. Since the acceleration sensor detects an acceleration signal by sampling, power corresponding to the number of samplings is consumed.
Therefore, the invention described in Patent Document 1 is characterized in that a threshold for detecting the number of steps is provided for the output of the acceleration sensor, and the sampling period when no walking vibration is detected and the sampling period after detecting the walking vibration are different.

JP 2001-143048 A

  However, the invention described in Patent Document 1 has a problem in that power is wasted because the acceleration signal is sampled at a constant period after detection of walking vibration.

  The present invention has been made in view of the above points, and provides an electronic device, a sampling cycle determination method, and a sampling cycle determination program that can avoid waste of power.

  (1) The present invention has been made to solve the above-described problems. One aspect of the present invention is an acceleration detection unit that samples an acceleration signal accompanying a user's movement, and a cycle of the acceleration signal. An electronic apparatus comprising: a signal period calculation unit that calculates a pitch period of movement; and a sampling period determination unit that determines a sampling period of the sampling based on the period of the acceleration signal.

  (2) According to another aspect of the present invention, in the electronic device described above, the sampling period determination unit determines the sampling period to be shorter as the pitch period is shorter.

  (3) According to another aspect of the present invention, in the electronic device described above, the signal period calculation unit calculates the period of the acceleration signal by moving average.

  (4) According to another aspect of the present invention, in the electronic device described above, the sampling period determination unit has an upper limit value or a lower limit value of the sampling period.

  (5) According to another aspect of the present invention, in the electronic device described above, the signal period calculation unit calculates a statistic of the period of the acceleration signal, and determines a moving average interval in the moving average based on the calculated statistic. It is characterized by calculating.

(6) According to another aspect of the present invention, the electronic device includes a mode determination unit that determines an operation mode based on an operation input, and the sampling cycle determination unit determines an upper limit value of the sampling cycle in advance. When the operation mode determined by the first sampling period and determined by the mode determination unit is a predetermined operation mode, the second sampling period is determined to be shorter than the first sampling period. It is characterized by that.

  (7) According to another aspect of the present invention, in the sampling period determination method for sampling an acceleration signal accompanying a user's movement in the electronic device, the electronic device samples an acceleration signal accompanying the user's movement. And a second step in which the electronic device calculates the period of the acceleration signal and calculates a pitch period of movement, and the electronic device determines the sampling period of the sampling based on the period of the acceleration signal. A sampling period determination method characterized by comprising: a third step.

  (8) According to another aspect of the present invention, there is provided a procedure for causing a computer of an electronic device that samples an acceleration signal accompanying a user's movement to cause the electronic device to sample the acceleration signal accompanying the user's movement; A sampling cycle determination program for executing a procedure for calculating a pitch cycle of movement and a procedure for determining the sampling cycle of the sampling based on the cycle of the acceleration signal.

  According to the present invention, since the sampling period is determined based on the acceleration signal detected by walking, it is possible to avoid waste of power that occurs regardless of the walking pitch.

1 is a schematic block diagram illustrating a configuration of an electronic device 100 according to a first embodiment of the present invention. It is a flowchart which shows the process which determines the sampling period which concerns on this embodiment. It is a figure which shows an example of the acceleration value at the time of a walk. It is a figure which shows an example of the acceleration value at the time of driving | running | working. It is a figure which shows an example of the relationship between the pitch and sampling frequency which concern on this embodiment. It is a flowchart which shows the process which determines the sampling period which concerns on the 2nd Embodiment of this invention. It is a table | surface which shows an example of the relationship between the dispersion value which concerns on this embodiment, and moving average area information. It is a flowchart which shows the process which determines the sampling period which concerns on the 3rd Embodiment of this invention. It is a table | surface which shows an example of the relationship between the deviation which concerns on this embodiment, and moving average area information. It is a schematic block diagram showing the structure of CPU which concerns on the 4th Embodiment of this invention. It is a figure showing an example of the relationship between the pitch which concerns on this embodiment, and a sampling frequency. It is a flowchart showing the process which determines the operation mode which concerns on this embodiment. It is a flowchart showing the process which determines the sampling period which concerns on this embodiment. It is a flowchart showing the process which determines the sampling period which concerns on the modification of this embodiment. It is a flowchart showing the process which determines the sampling period which concerns on the other modification of this embodiment.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a block diagram illustrating a configuration of an electronic device 100 according to an example of an embodiment of the present invention.
In FIG. 1, an electronic device 100 includes a CPU (Central Processing Unit) 101, an oscillation circuit 102, a frequency dividing circuit 103, an operation input unit 104, an acceleration detection unit 106, a display unit 108, a RAM (Random Access Memory; A random access memory (110), a ROM (Read Only Memory) 111, and a power supply unit 112 are included.
The electronic device 100 is, for example, a pedometer 100 or a wristwatch with a step count function that detects the number of steps associated with a user's walk and displays the detected number of steps and its accumulated value.

The CPU 101 reads out a program stored in advance in the ROM 111 when the electronic device 100 is turned on, and operates according to the read program to control the entire operation of the electronic device 100. Functions related to the operation of other functional units will be described together with the operation of each functional unit.
The oscillation circuit 102 generates an oscillation signal having a constant frequency (for example, 32 kHz) and outputs the oscillation signal to the frequency dividing circuit 103. The frequency dividing circuit 103 divides the oscillation signal input from the oscillation circuit 102 by a predetermined frequency dividing ratio, generates a time measurement signal, and outputs it to the CPU 101. The CPU 101 generates time information by counting the time signal. The operation input unit 104 is, for example, a key input unit that includes a key that can be operated by the user from the outside and outputs an operation input signal to the CPU 101 when the key is pressed. The display unit 108 displays the number of steps, time, or date / time information measured by the CPU 101. The RAM 110 temporarily stores various setting information and calculation data such as measured step count information, time information, and date / time information. The power supply unit 112 is a battery, for example, and supplies power to each component of the electronic device 100 such as the CPU 101 and the acceleration detection unit 106.

  The acceleration detection unit 106 generates an acceleration signal corresponding to an acceleration generated based on an operation such as walking or running by the user. The acceleration detection unit 106 is a so-called acceleration sensor, for example, a three-axis acceleration sensor that generates an acceleration signal along each coordinate axis direction of x, y, and z. The acceleration detection unit 106 is activated and detects acceleration at the sampling period indicated by the sampling signal input from the CPU 101. The acceleration detection unit 106 outputs the detected acceleration signal to the CPU 101. Thereafter, the acceleration detection unit 106 pauses the acceleration detection until the next sampling opportunity.

  The CPU 101 (signal cycle calculation unit, sampling cycle determination unit) calculates the cycle of the acceleration signal based on the acceleration signal input from the acceleration detection unit 106. The CPU 101 determines the sampling period based on the calculated acceleration signal period. The CPU 101 generates a sampling signal indicating the determined sampling period. The CPU 101 acquires an acceleration signal from the acceleration detection unit 106 for each sampling period in which the generated sampling signal is determined.

  The above-described example is a configuration in which the acceleration detection unit 106 is activated at the sampling period indicated by the sampling signal input from the CPU 101 to detect acceleration, but the present embodiment is not limited to this example. In the present embodiment, for example, the CPU 101 may generate a sampling signal every certain sampling period, and output the generated sampling signal to the acceleration detection unit 106. At this time, the generated sampling signal does not have to indicate the sampling period, and may be a pulse signal, for example. When the acceleration detection unit 106 receives a sampling signal from the CPU 101, the acceleration detection unit 106 outputs the generated acceleration signal to the CPU 101. Since the acceleration detection unit 106 consumes power in proportion to the number of times the sampling signal is input, the power consumption can be reduced if the number of times the sampling signal is input decreases.

Next, processing for determining the sampling period in the present embodiment will be described with reference to the drawings. FIG. 2 is a flowchart showing processing for determining the sampling period according to the present embodiment.
(Step S <b> 201) The CPU 101 generates a sampling signal indicating a predetermined sampling period, and outputs the generated sampling signal to the acceleration detection unit 106. The sampling period initially used is an initial value read from the ROM 111, for example. The acceleration detection unit 106 detects the acceleration signal and outputs it to the CPU 101 at the sampling period indicated by the sampling signal input from the CPU 101. When the acceleration detection unit 106 includes a plurality of sensitivity axes (for example, two; x, y axes), and the detected acceleration signal includes an acceleration value in each axis direction (hereinafter also referred to as an acceleration value). In other words, the CPU 101 may obtain a composite value (for example, square root of sum of squares √a _x ² + a _y ² ) of acceleration values (for example, a _x , a _y ) included in the acceleration signal in each axial direction. . In this case, the CPU 101 uses the obtained composite value as the acceleration for each sampling. Thereafter, the process proceeds to step S202.

(Step S <b> 202) The CPU 101 calculates a cycle (pitch cycle) of acceleration values from a time series of acceleration values indicated by the acceleration signal input from the acceleration detection unit 106. A method for calculating the period will be described with reference to FIG.
FIG. 3 is a diagram illustrating an example of acceleration values during walking. The vertical axis represents acceleration a (sample value), and the horizontal axis represents time t (seconds). In general, when a user walks, both feet are moved back and forth alternately. Therefore, when the feet land on the ground, the acceleration periodically varies as shown in FIG. Therefore, the CPU 101 generates rectangular wave information that gives a value of 1 when the acceleration a exceeds a threshold value e greater than zero and gives a value of 0 (zero) when the acceleration a is equal to or less than the threshold value e. To do. For example, based on the generated rectangular wave information, the CPU 101 calculates the time between the time when the value has changed from zero to 1 most recently in the rectangular wave information and the time when the value has changed from zero to 1 most recently. The pitch period (acceleration signal period) is determined. Then, it progresses to step S203

  FIG. 4 is a diagram illustrating an example of acceleration values during traveling. The vertical axis represents acceleration a (sample value), and the horizontal axis represents time t (seconds). Compared to the acceleration value shown in FIG. 3, it is shown that the pitch period is shorter (the pitch is higher) and the absolute value of the acceleration value is larger when running than when walking.

(Step S203) The CPU 101 determines a sampling period based on the determined pitch period. For example, the CPU 101 calculates a pitch (the number of steps per unit time) that is the reciprocal of the pitch period, and determines that the calculated pitch is proportional to the sampling frequency (the reciprocal of the sampling period). As a result, the power consumption in the acceleration detection unit 106 accompanying sampling is also proportional to this, so that power consumption can be reduced especially when the pitch period is long (the pitch is low). Thereafter, the process ends.

However, as shown in FIG. 5, a lower limit f _p1 and an upper limit f _p2 of the pitch are provided. That is, the CPU 101 determines a constant sampling frequency f _s1 when the pitch is lower than the lower limit f _p1 . When the pitch is higher than the upper limit f _p2 , the CPU 101 determines a constant sampling frequency f _s2 . Thereby, in the electronic device 100, when the pitch is zero (the pitch period is infinite), it is possible to prevent the sampling from being stopped. Moreover, in the electronic device 100, when the pitch is high, it is possible to prevent the power consumption from increasing on the contrary.

Further, the lower limit f _p1 and the upper limit f _p2 of the pitch are determined to be, for example, 0.5 times / second and 4.0 times / second, respectively, taking into account the pitch associated with human average walking or running. Thereby, in the electronic device 100, sampling is not interrupted even when the pitch is zero, that is, when it is stopped. Further, the sampling frequency f _s2 when the pitch takes the upper limit f _p2 is determined according to the maximum power consumption allowed by the acceleration detection unit 106. In consideration of the fact that the detected pitch is often lower than the upper limit f _p2 , the power consumption in the acceleration detection unit 106 is lower than the maximum power consumption. Therefore, the CPU 101 determines the sampling frequency so that the pitch increases monotonously (eg, directly proportional) from the lower limit f _s1 to the upper limit f _s2 as the pitch increases from the lower limit f _p1 to the upper limit f _p2 .

  As described above, according to the present embodiment, the sampling period is determined so as to increase or decrease according to the period of the acceleration signal accompanying walking, and the sampling of the acceleration signal is performed according to the sampling period. The number of samplings is reduced, and waste of power is avoided.

(Second Embodiment)
Next, a second embodiment of the present invention will be described in detail with reference to the drawings. Since the configuration and function of the electronic device according to the present embodiment are the same as those of the electronic device 100 according to the first embodiment, processing for determining the sampling period according to the present embodiment will be described with reference to FIG. FIG. 6 is a flowchart showing processing for determining the sampling period according to the present embodiment. The process for determining the sampling period according to the present embodiment is common to the process shown in FIG. 2 in that it has steps S201 to S203, and is different in that it has steps S212, S214, and S215. Hereinafter, the difference will be mainly described.

(Step S212) The CPU 101 calculates moving average values of the latest and past pitch periods. The number of sections in which the moving average is calculated, that is, the number of pitch periods to be calculated is, for example, eight including the latest pitch period. As a result, a value that is more stable than the pitch period calculated each time can be obtained without taking a moving average. When obtaining the moving average, the weighting factor for each pitch period may use the same value to place importance on a relatively past pitch period, or may use a larger value as it becomes closer to the past. In the latter case, the sampling period determined by the electronic device 100 is easy to follow due to a sudden change in the pitch period. Thereafter, the process proceeds to step S203.
In step S203, the CPU 101 determines the sampling period of the acceleration signal based on the moving average value of the pitch period calculated in step S212.

(Step S214) The CPU 101 calculates a statistic for the most recent sampling based on the statistic of the most recent pitch period and the pitch period at the previous time. The statistics calculated by the CPU 101 are, for example, an average value and a variance value. Thereafter, the process proceeds to step S215.
(Step S215) The CPU 101 determines moving average section information based on the calculated statistics. The moving average section information is information indicating a section for which a moving average is to be calculated, for example, information indicating the number of pitch periods for which the above moving average value is to be calculated, or a weighting factor for the latest and past pitch periods. . In the RAM 110, for example, the variance value and the moving average section information are stored in advance in association with each other. The CPU 101 reads out and determines moving average section information corresponding to the statistic calculated from the RAM 110. Thereafter, the process ends.

  FIG. 7 shows an example of the relationship between the variance value and the moving average interval information according to this embodiment. In the example of FIG. 7, the number of pitch periods indicated by the moving average section information decreases as the variance value increases. As a result, the larger the variance value, that is, the more the pitch period fluctuates, the CPU 101 can calculate the moving average value with an emphasis on the latest pitch period and reflect the latest state. In order to obtain a similar effect, a value that increases as the nearest pitch period in the weighting coefficient for obtaining the moving average as the variance value increases may be used as the moving average output section information. The CPU 101 uses the determined moving average section information when calculating the moving average value in the next step S212.

  Thus, according to this embodiment, the moving average value of the cycle of the acceleration signal accompanying walking is obtained, and the sampling cycle is determined based on the moving average value. Therefore, according to this embodiment, acceleration information can be calculated stably. Also, in this embodiment, by calculating the statistics of the period of the acceleration signal and determining the moving average interval information according to this statistic, the stable calculation of the sampling period that varies depending on the user and the ability to follow the latest acceleration information Can be realized.

(Third embodiment)
Next, a third embodiment of the present invention will be described in detail with reference to the drawings. Since the configuration and function of the electronic device according to the present embodiment are the same as those of the electronic device 100 according to the first or second embodiment, processing for determining the sampling period according to the present embodiment will be described with reference to FIG. . FIG. 8 is a flowchart showing processing for determining a sampling period according to the present embodiment. The sampling cycle determination method according to the present embodiment is common to the sampling cycle determination method shown in FIG. 6 in that steps S201 to S203 and step S212 are included, and is different in that steps S213 and S216 are included. Hereinafter, the difference will be mainly described.

(Step S213) The CPU 101 calculates a pitch period deviation which is a difference value between the latest pitch period and the moving average value of the pitch periods. Thereafter, the process proceeds to step S216.
(Step S216) The CPU 101 determines moving average section information based on the calculated pitch period deviation. Here, in the RAM 110, for example, the deviation and the moving average section information are stored in association with each other in advance. The CPU 101 reads out and determines moving average section information corresponding to the statistic calculated from the RAM 110. Thereafter, the process proceeds to step S203.

  FIG. 9 shows an example of the relationship between the deviation according to the present embodiment and the moving average section information. In the example of FIG. 9, the number of pitch periods indicated by the moving average section information decreases as the deviation increases. As a result, the larger the deviation, that is, the more the pitch period fluctuates, the CPU 101 can calculate the moving average value with an emphasis on the latest pitch period and reflect the latest state. In order to obtain the same effect, as the deviation becomes larger, a value that becomes larger in the weighting coefficient for obtaining the moving average as the nearest pitch period may be used as the moving average calculation section information. The CPU 101 uses the determined moving average section information when calculating the moving average value in the next step S212.

  Thus, according to this embodiment, the moving average value of the cycle of the acceleration signal accompanying walking is obtained, and the sampling cycle is determined based on the deviation from the moving average value. Thereby, it is possible to realize control of followability to the latest acceleration information based on the variation amount of the pitch period indicated by the deviation. For example, according to the present embodiment, when the fluctuation of the pitch period is significant, the latest pitch period can be quickly followed, and when the fluctuation of the pitch period is moderate, a stable pitch period can be obtained.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described in detail with reference to the drawings. The electronic device 100 (see FIG. 1) according to the present embodiment has the same configuration as the first to third embodiments. However, the CPU 101 according to the present embodiment has a configuration described below.
FIG. 10 is a schematic block diagram showing the configuration of the CPU 101 according to the present embodiment.
The CPU 101 includes a mode determining unit 1011, a time measuring unit 1012, a signal cycle calculating unit 1013, and a sampling cycle determining unit 1014.

  The mode determination unit 1011 determines an operation mode based on the operation input signal input from the operation input unit 104. The mode determination unit 1011 stores operation mode information indicating the determined operation mode in the RAM 110. The operation mode includes, for example, an elapsed time measurement mode (chronograph measurement mode) for measuring elapsed time, a time display mode for displaying the current time, and a travel mode (run mode). The travel mode is an operation mode in which an elapsed time is measured during travel. In the following description, the elapsed time measurement mode described above is sometimes called a normal mode (normal mode) and may be distinguished from a travel mode.

When the operation input signal input from the operation input unit 104 is a signal indicating an operation mode, the mode determination unit 1011 determines an operation mode corresponding to the operation input signal. For example, when an operation input signal indicating the travel mode is input, the mode determination unit 1011 determines the operation mode as the travel mode. When the operation input signal indicating the normal mode is input, the mode determination unit 1011 determines the operation mode as the normal mode.
Note that the mode determination unit 1011 may select an operation mode by sequentially switching one operation mode from a plurality of preset operation modes each time an operation input signal is input.
Further, the mode determining unit 1011 may change the operation mode to an operation mode other than the travel mode and the normal mode, for example, the time display mode when the operation input signal indicating reset is input and the travel mode is already selected. Good. The reset is to delete the measurement time information indicating the measured measurement time after the measurement of the elapsed time is finished. As a result, after the measurement of the elapsed time is completed, the user can change the operation mode without performing an operation input only for changing the travel mode to the normal mode.

The timekeeping unit 1012 counts the number of timekeeping signals input from the frequency dividing circuit 103 and generates time information. The timer unit 1012 outputs the generated time information to the display unit 108.
When the operation mode information stored in the RAM 110 indicates the travel mode or the normal mode, the time measuring unit 1012 performs the following process.

When the start signal is input from the operation input unit 104, the time measuring unit 1012 starts measuring elapsed time based on the time measuring signal input from the frequency dividing circuit 103. The start signal is a signal indicating that measurement of elapsed time is started. The timer unit 1012 outputs an elapsed time signal indicating the measured elapsed time to the display unit 108.
When the lap signal is input as the operation input signal from the operation input unit 104, the time measuring unit 1012 stores the generated elapsed time signal in the RAM 110. The lap signal is a signal indicating that an elapsed time during measurement is displayed. The timer unit 1012 maintains (holds) the elapsed time signal output to the display unit 108 as an elapsed time signal indicating the elapsed time when the lap signal is input in advance (for example, 3 seconds). However, the timer unit 1012 continues to measure the elapsed time.

When the stop signal is input as the operation input signal from the operation input unit 104, the time measuring unit 1012 stops measuring the elapsed time, and stores the elapsed time signal when the measurement is stopped in the RAM 110. The stop signal is a signal indicating that the measurement of elapsed time is stopped. The timer unit 1012 maintains an elapsed time signal output to the display unit 108.
When a reset signal is input as an operation input signal from the operation input unit 104, the timer unit 1012 deletes the elapsed time signal stored in the RAM 110 and generates an elapsed time signal representing an initial value (for example, zero). The timer unit 1012 outputs the generated elapsed time signal to the display unit 108.

The signal period calculation unit 1013 acquires an acceleration signal from the acceleration detection unit 106 for each sampling period represented by the sampling signal input from the sampling period determination unit 1014.
The signal period calculation unit 1013 calculates the pitch period based on the acceleration signal acquired from the acceleration detection unit 106. That is, the acceleration detection unit 106 executes the above-described steps S201 and S202. The signal period calculation unit 1013 outputs a pitch period signal representing the calculated pitch period to the sampling period determination unit 1014.

  The sampling period determining unit 1014 calculates the sampling period based on the pitch period represented by the pitch period signal input from the signal period calculating unit 1013. That is, the sampling period determination unit 1014 executes the above-described step S203. The sampling period determination unit 1014 generates a sampling signal representing the calculated sampling period, and outputs the generated sampling signal to the signal period calculation unit 1013.

Sampling period determining unit 1014 determines whether or not the operation mode information stored in RAM 110 represents a travel mode. When the operation mode information represents the normal mode, the sampling cycle determination unit 1014 determines the lower limit of the pitch as f _p1 described above. When the operation mode information represents the travel mode, the sampling cycle determination unit 1014 determines the lower limit of the pitch as _fp3 .

FIG. 11 is a diagram illustrating an example of the relationship between the pitch and the sampling frequency according to the present embodiment.
In FIG. 11, the horizontal axis represents the pitch, and the vertical axis represents the sampling frequency. A solid line represents a sampling frequency corresponding to a given pitch when the operation mode information is the traveling mode.
As shown in FIG. 11, the lower limit f _p3 of the pitch is a value higher than the above-described f _p1 . However, _fp3 is a value lower than the upper limit _fp2 .
The lower limit f _{s3 of the} sampling frequency is a value higher than f _s1 . However, f _s3 is a value lower than the upper limit f _s2 .

11, when the operation mode information indicates the running mode, the sampling period determination unit 1014, whether the pitch f _p indicated by pitch period signal is equal to the lower limit f _p3, is lower than the lower limit f _p3, corresponding sampling frequency f _This means that the sampling period is determined so that _s becomes the lower limit f _s3 . Sampling period determination unit 1014 is higher than the pitch f _p is the lower limit f _p3 indicated pitch period signal, is lower than the upper limit f _p2, the corresponding sampling frequency f _s to be proportional to the pitch f _p defining the sampling period Represents that. The sampling period thus determined is proportional to the pitch period based on the pitch period signal. Sampling period determination unit 1014, whether the pitch f _p indicated by pitch period signal is equal to the upper limit f _p2, is higher than the upper limit f _p2, that determine the sampling period such that the corresponding sampling frequency f _s is the upper limit f _s2 Represents.
On the other hand, when the operation mode information represents the normal mode, the sampling period determining unit 1014 determines the sampling period using f _p1 which is a value lower than f _p3 instead of f _p3 as the lower limit of the pitch (see FIG. 5).

Next, processing for determining an operation mode performed by the mode determination unit 1011 according to the present embodiment will be described.
FIG. 12 is a flowchart showing processing for determining an operation mode according to the present embodiment.
(Step S <b> 301) The mode determination unit 1011 receives an operation input signal from the operation input unit 104. Thereafter, the process proceeds to step S302.
(Step S302) The mode determination unit 1011 determines whether or not the input operation input signal is a signal indicating a travel mode. When it is determined that the signal indicates the travel mode (Yes in step S302), the process proceeds to step S303. When it is determined that the signal is not a signal indicating the travel mode (No in step S302), the process proceeds to step S304.
(Step S303) The mode determination unit 1011 determines the operation mode as the travel mode, and stores operation mode information representing the travel mode in the RAM 110. Thereafter, the process ends.
(Step S304) The mode determination unit 1011 determines the operation mode as the normal mode, and stores the operation mode information indicating the normal mode in the RAM 110. Thereafter, the process ends.

Next, processing for calculating a sampling period according to the present embodiment will be described.
FIG. 13 is a flowchart showing processing for calculating a sampling period according to the present embodiment.
The signal period calculation unit 1013 acquires an acceleration signal from the acceleration detection unit 106 for each sampling period represented by the sampling signal input from the sampling period determination unit 1014, and executes the above-described steps S201 and S202. Thereafter, the signal period calculation unit 1013 outputs a pitch period signal representing the calculated pitch period to the sampling period determination unit 1014, and the process proceeds to step S401.

(Step S401) The sampling period determination unit 1014 determines whether the operation mode information stored in the RAM 110 represents a travel mode or a normal mode. When it is determined that the travel mode is represented (step S401 Yes), the process proceeds to step S402. If it is determined that it represents the normal mode (No in step S401), the process proceeds to step S203.
(Step S402) sampling period determination unit 1014, the pitch f _p representing the pitch period signal inputted from the signal cycle calculator 1013 determines whether lower than the lower limit f _p3. When it is determined that the value is lower than the lower limit _fp3 (step S402 Yes), the process proceeds to step S403. If it is determined that the value is equal to or higher than the lower limit _fp3 (No in step S402), the process proceeds to step S203.
(Step S403) sampling period determination unit 1014 defines a lower limit f _p3 the pitch f _p representing the pitch period signal. Thereafter, the process proceeds to step S203.
That is, the sampling period determination unit 1014, if the operation mode information indicates the running mode, the lower limit of the pitch is f _p3, if the operation mode information indicates normal mode, the lower limit of the pitch as f _p1, perform the step S203 To determine the sampling period. As a result, when the operation mode is the traveling mode, the sampling cycle determination unit 1014 determines the sampling cycle such that the upper limit value is the reciprocal (1 / f _s3 ) of the sampling frequency f _s3 . The upper limit value of the sampling period is shorter than the value (1 / f _s1 ) when the operation mode is the normal mode, and is longer than the lower limit value (1 / f _s2 ) of the sampling period.

(Modification 1)
Next, Modification 1 of the present embodiment will be described. In the first modification, the CPU 101 has the same configuration as that shown in FIG. However, the first modification has the following differences from the configuration shown in FIG.
The signal period calculation unit 1013 calculates the moving average value by executing the above-described step S212 based on the moving average section information stored in the RAM 110. The signal period calculator 1013 outputs a pitch period signal representing the calculated moving average value instead of the above-described pitch period to the sampling period determining unit 1014.
The signal period calculation unit 1013 executes the above-described steps S214 and S215 using the latest pitch period, and stores the calculated statistic, for example, moving average interval information, in the RAM 110.

Next, a process for determining the sampling period according to the first modification of the present embodiment will be described.
FIG. 14 is a flowchart showing processing for determining a sampling period according to the first modification of the present embodiment.
In the first modification, the signal cycle calculation unit 1013 executes step S212 after step S202, and executes step S214 and step S215 after step S203, which is the same as the sampling cycle calculation process shown in FIG. Different.
Accordingly, in the first modification, by using the moving average value of the pitch period, the sampling period (1 / f _s3 ) corresponding to the sampling frequency f _s3 can be used as the upper limit value, and the sampling period can be calculated stably. . As a result, when the operation mode is the traveling mode, the sampling cycle determination unit 1014 determines the sampling cycle such that the upper limit value is the reciprocal (1 / f _s3 ) of the sampling frequency f _s3 .

(Modification 2)
Next, a second modification of the present embodiment will be described. In the second modification, the CPU 101 has the same configuration as that shown in FIG. However, the second modification has the following differences from the configuration shown in FIG.
The signal period calculation unit 1013 calculates the moving average value by executing the above-described step S212 based on the moving average section information stored in the RAM 110. The signal period calculation unit 1013 calculates a deviation between the moving average value calculated by executing the above-described step S213 and the latest pitch period, and further, based on the deviation calculated by executing the above-described step S216, the moving average interval To decide. The signal period calculation unit 1013 stores the moving average section information representing the calculated moving average section in the RAM 110. The signal period calculator 1013 outputs a pitch period signal representing the calculated moving average value instead of the above-described pitch period to the sampling period determining unit 1014.

Next, a process for determining the sampling period according to the second modification of the present embodiment will be described.
FIG. 15 is a flowchart showing a process for determining a sampling period according to the second modification of the present embodiment.
In the second modification, the signal cycle calculation unit 1013 executes step S212, step S213, and step S216 after step S202, and executes step S401 after step S216. The sampling cycle shown in FIG. Different from the calculation process.
Thus, in the second modification, the followability to the acceleration information is controlled according to the variation amount of the pitch period, and the sampling period is calculated with the sampling period (1 / f _s3 ) corresponding to the sampling frequency f _s3 as the upper limit value. can do.

In the above description, the sampling period determination unit 1014, a pitch f _p represented by the input pitch period signal is lower than the lower limit f _p3 the pitch and described as provided the pitch f _p to the lower limit f _p3 for example . In this embodiment, this not limited, the sampling period determination unit 1014, the sampling frequency f _s is, when lower than the lower limit f _s3 sampling frequency corresponding to the lower limit f _p3 pitch period, the sampling frequency f _s The lower limit may be set to f _s3 . Here, the sampling frequency f _s and the lower limit f _s3 is its lower limit, respectively pitch f _p, and the sampling frequency corresponding to f _p3.

As described above, in the present embodiment, the operation mode is determined based on the operation input, and when the determined operation mode is the travel mode, the upper limit value of the sampling period is set to the reciprocal of the lower limit f _s3 of the sampling frequency (1 / f _s3 ). The upper limit value (second sampling period) of the sampling period is shorter than the upper limit value (1 / f _s1 ) (first sampling period) when the operation mode is the normal mode.
Accordingly, since the sampling period is determined to be equal to or shorter than the second sampling period even immediately after the start of the user's travel, the sampling of the acceleration signal is performed with respect to the pitch increase immediately after the start of the travel. Follow early. Therefore, even when the high pitch state and the low pitch state are irregularly repeated, the pitch can be measured with high accuracy. The case where the pitch is high and low is repeated irregularly, for example, in order to avoid vehicles and other passers-by, such as when a user runs in a city area, and to follow traffic signal instructions, This is a case where the stop and start of running are repeated.

Note that a part of the electronic device 100 in the above-described embodiment, for example, the CPU 101 may be realized by a computer. In that case, the program for realizing the control function may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read by a computer system and executed. Here, the “computer system” is a computer system built in the CPU 101 and includes an OS and hardware such as peripheral devices. The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” is a medium that dynamically holds a program for a short time, such as a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line, In such a case, a volatile memory inside a computer system serving as a server or a client may be included and a program that holds a program for a certain period of time. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.
Further, a part or all of the CPU 101 in the above-described embodiment may be realized as an integrated circuit such as an LSI (Large Scale Integration). Each functional block of the CPU 101 may be individually made into a processor, or a part or all of them may be integrated into a processor. Further, the method of circuit integration is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor. Further, in the case where an integrated circuit technology that replaces LSI appears due to progress in semiconductor technology, an integrated circuit based on the technology may be used.

  As described above, the embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to the above, and various design changes and the like can be made without departing from the scope of the present invention. It is possible to

DESCRIPTION OF SYMBOLS 100 ... Electronic device, 101 ... CPU, 102 ... Oscillator circuit, 103 ... Frequency divider circuit,
104 ... operation input unit, 106 ... acceleration detection unit, 108 ... display unit,
110 ... RAM, 111 ... ROM, 112 ... power supply unit,
1011 ... mode determination unit, 1012 ... timing unit, 1013 ... signal cycle calculation unit,
1014: Sampling cycle determining unit

Claims (8)

An acceleration detector that samples an acceleration signal associated with the movement of the user;
A period of the acceleration signal, a signal period calculation unit for calculating a pitch period of movement;
A sampling period determining unit that determines a sampling period of the sampling based on the period of the acceleration signal;
An electronic device comprising:   The electronic apparatus according to claim 1, wherein the sampling period determining unit determines the sampling period to be shorter as the pitch period is shorter.   The electronic device according to claim 1, wherein the signal period calculation unit calculates the period of the acceleration signal by moving average.   The electronic apparatus according to claim 1, wherein the sampling period determination unit has an upper limit value or a lower limit value of the sampling period.   The electronic apparatus according to claim 3, wherein the signal period calculation unit calculates a statistic of the period of the acceleration signal, and calculates a moving average section in the moving average based on the calculated statistic. A mode determining unit that determines an operation mode based on an operation input,
The sampling period determining unit determines an upper limit value of the sampling period as a predetermined first sampling period, and when the operation mode determined by the mode determining unit is a predetermined operation mode, the first sampling period The electronic apparatus according to claim 1, wherein the second sampling period is shorter than the period. In a sampling period determination method for sampling an acceleration signal accompanying movement of a user in an electronic device,
A first process in which the electronic device samples an acceleration signal associated with the movement of the user;
A second process in which the electronic device calculates a period of the acceleration signal and calculates a pitch period of movement;
A third process in which the electronic device determines a sampling period of the sampling based on a period of the acceleration signal;
A sampling period determination method characterized by comprising: In the computer of the electronic device that samples the acceleration signal that accompanies the movement of the user,
A procedure for causing the electronic device to sample an acceleration signal associated with the movement of the user;
A procedure for calculating a period of the acceleration signal and calculating a pitch period of movement;
Determining a sampling period of the sampling based on a period of the acceleration signal;
Sampling cycle determination program to execute.

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