JP4604808B2 - Activity meter - Google Patents

Description

  The present invention relates to an activity meter that measures exercise intensity for a user.

  An exercise level temporal storage device has been provided as a device for detecting life activity of a user and presenting life improvement data to the user (for example, Patent Document 1).

  The method of measuring exercise intensity used in the exercise level temporal storage device disclosed in Patent Document 1 uses a single acceleration sensor to count the number of steps of the user, and the count value and the maximum output from the acceleration sensor. This is a method of calculating a representative value of the momentum level based on the voltage value and recording a change over time.

Another conventional example is a body motion detection device (for example, Patent Document 2). The body motion detection device disclosed in Patent Document 2 uses a plurality of acceleration sensors, selects an acceleration sensor in the vertical direction, and detects the number of steps from the detection output of the acceleration sensor. By selecting and calculating one of the sensors, the motion level is calculated for acceleration in only one direction.
Japanese Patent No. 3027346 (FIGS. 1 and 2) JP 2002-191580 A (paragraph numbers 0020 to 0024)

  The motion level timing storage device disclosed in Patent Document 1 calculates a motion level for acceleration in only one direction, and cannot accurately measure the activity of a human body that moves in a complex manner. In addition, since the calculation method mainly counts the number of steps, there is a problem that the exercise level can be calculated only when walking (running).

  Further, in the body motion detection device disclosed in Patent Document 2, one of a plurality of acceleration sensors is selected and calculation is performed, so that the motion level is calculated for acceleration in only one direction. There was a problem that it was not possible to accurately measure the activity of the human body moving in complex space.

  To solve this problem, rather than capturing acceleration in only one direction, it is more accurate if multiple acceleration sensors are used to synthesize acceleration components in various directions, thereby capturing the movement of the human body. The amount of activity can be detected. However, in order to realize an apparatus using such a method, a plurality of highly accurate acceleration sensors and a highly accurate microcomputer capable of calculating a plurality of acceleration sensor outputs at high speed are required. Moreover, these high-precision accelerometers and high-precision microcomputers consume a large amount of power, and when using a battery power source, it is necessary to use a large battery in consideration of the battery life. There is a problem that the measuring device becomes large and heavy.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide an active mass meter with reduced power consumption.

In order to achieve the above object, according to the first aspect of the present invention, an acceleration sensor, detection means for periodically detecting acceleration based on the output of the acceleration sensor, and exercise intensity based on the detected acceleration of the detection means. And a calculation means for calculating as a quantity, and a detection period changing means for changing the period based on a detected acceleration of the detection means or an amount of activity calculated by the calculation means, and the detection period changing means It is characterized in that the determination time for determining is changed to be shorter when the detected acceleration of the detection means or the amount of change per time of the activity amount is large, and longer when it is small.

According to the first aspect of the present invention, the acceleration sensor and the calculation means can be intermittently driven by changing the cycle of detecting the acceleration from the output of the acceleration sensor, so that the power consumption can be suppressed, and the battery power supply can be controlled. In the case of driving using, it is possible to drive for a long time with a small battery. In addition, the period change was quickly shortened for sudden changes in detected acceleration or activity to prevent omissions, and continuous changes in detected acceleration or activity were confirmed when the detected acceleration or activity changed slowly. The period can be changed later, and the detection period is not changed by a slight signal such as noise. In addition, since the detection cycle can be quickly changed for detection of actual body movement, detection can be performed without reducing detection accuracy.

According to a second aspect of the present invention, in the first aspect of the invention, the period change by the detection period changing means shortens the period when the detected acceleration of the detection means or the amount of activity calculated by the calculation means is greater than a predetermined value. The period is lengthened when the detected acceleration or the activity amount is smaller than the predetermined value.

According to the invention of claim 2 , by changing the cycle according to the detected acceleration or the amount of activity, the power consumption can be suppressed without degrading the measurement accuracy.

According to a third aspect of the present invention, in the first or second aspect of the invention, the detection period changing means makes a judgment based on the amount of activity when the period is lengthened, and is detected by the detecting means when the detection period is shortened. It is characterized in that it is performed with the magnitude of acceleration.

According to the invention of claim 3 , since the activity amount is small when the detection cycle is lengthened, the accuracy is improved by detecting accurately according to the activity amount calculated by the activity amount calculating means and determining the cycle. be able to. In addition, when the detection cycle is shortened, since the transition from a state where there is little activity to a state where there is a large amount of activity is performed, it can be performed quickly only with the output level of the acceleration sensor so that the transition can be made quickly.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the measurement unit includes a measurement unit that measures the number of vibrations per fixed time from the detected acceleration of the detection unit, and the detection cycle change unit is the number of vibrations measured by the measurement unit. The detection period is changed according to the above.

According to the invention of claim 4 , by changing the detection cycle by measuring the number of vibrations, it is possible to easily detect the operating speed of the human body without using the calculation means, and to detect it accordingly It is possible to measure the amount of activity with high accuracy by changing the cycle.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects of the present invention, a power supply unit that supplies a necessary minimum voltage at which the acceleration sensor can operate according to the detection period is provided. To do.

According to the invention of claim 5, since the minimum necessary voltage that can be operated according to the detection cycle is supplied to the acceleration sensor, it is possible to suppress the power consumption of the acceleration sensor while ensuring the operation. This is particularly advantageous for power supplies that have voltage fluctuations due to wear.

  The present invention can intermittently drive the acceleration sensor and the arithmetic means by changing the cycle of detecting the acceleration from the output of the acceleration sensor, so that the power consumption can be suppressed and the battery power source is used for driving. There is an effect that it can be driven for a long time with a small battery.

Embodiments of the present invention will be described below.
(Embodiment 1)
As shown in FIG. 1, the activity meter of the present embodiment includes a three-axis acceleration sensor unit 1 including three acceleration sensors 1x, 1y, and 1z that detect accelerations in the respective x, y, and z axes, An arithmetic processing unit 2 comprising detection means 20 for periodically detecting the output of each axis of the axial acceleration sensor unit 1 and detecting acceleration, and calculation means 21 for calculating exercise intensity from the acceleration detected by the detection means 20 as an activity amount. And a function for changing the detection cycle in which the detection means 20 captures the output from the acceleration sensor unit 1 and detects the acceleration according to the amount of activity (acceleration may be used) and a timing corresponding to the detection cycle and 3 A detection period changing unit 3 having a timing setting function for outputting a timing signal for setting an operation timing to the axial acceleration sensor unit 1, a display unit 4 for displaying information such as a calculated activity amount, A storage unit 5 for storing the data of calculation results and the like, and a battery power supply 6.

  The arithmetic processing unit 2 and the detection cycle changing unit 3 are configured by using, for example, a microcomputer, and the arithmetic unit 20 has a function for controlling display on the display unit 4 and a function for controlling reading and writing of data with respect to the storage unit 5. Is given.

  The acceleration sensor is capable of measuring the acceleration of the human body, and is not particularly limited as long as it is an acceleration sensor having one or more axes (the same applies to Embodiments 2 to 5 described later).

  The operation of this embodiment will be described with reference to the flowchart of FIG.

  Now, in step S1, the detection cycle changing unit 4 sets a timing corresponding to a certain detection cycle Ta1, and gives a timing signal to the arithmetic processing unit 2 and the three-axis acceleration sensor unit 1 to operate them. The detection means 20 of the arithmetic processing unit 2 detects the acceleration of each axis by taking the outputs of the acceleration sensors 1x to 1z in step S2 according to the timing signal. Here, the detection cycle Ta1 is about 10 Hz to 100 Hz.

  Next, the calculation means 2 determines whether or not the current detection cycle Ta1 is a cycle Tb set when the activity amount of the wearer is small (step S3). The calculation which calculates | requires exercise intensity as an active mass based on the acceleration of each axis which the means 20 has detected is performed (step S4), the calculation result is memorize | stored in the memory | storage part 5, and the process displayed on the display part 4 is performed.

  The detection cycle changing unit 4 fetches the calculation result from the calculation means 21, and determines in step S5 whether the activity amount that is the calculation result is greater than a preset threshold value Thb. As a result of the determination, when the activity amount is smaller than the threshold value Thb, the count value Ctb by the built-in counter is counted up (step S6).

In this step S6, the detection cycle changing unit 4 compares the counted up count value Ctb with the threshold value (2) in step S7. If the count value Ctb exceeds the threshold value (2), the detection period changing unit 4 continuously performs the activity. It is detected that the amount continues to be smaller than the threshold Thb. That is, if the activity amount is continuously smaller than the threshold Thb, it can be determined that the activity meter is not attached to the human body or that the person wearing the activity meter is not moving, and the detection cycle changing unit 4 sets the detection cycle. The timing is changed from Ta 1 to Tb, and the timing corresponding to the cycle Tb is set in step S1. Here, the period Tb is about 0.1 Hz to 5 Hz.

  In this way, when it is determined that the activity meter is not attached to the human body or the person to whom the activity meter is attached is not moving, the sampling period of the activity meter is extremely slowed to thereby reduce the triaxial acceleration sensor. The time for operating the unit 1 and the arithmetic processing unit 2 can be shortened, and a reduction in current consumption can be realized.

  Next, a case where the activity meter is operating at the detection cycle Tb will be described.

Now, when the detection cycle Tb is changed, the calculation means 20 does not perform the activity amount calculation. Then, the process proceeds to step S9 through steps S1 to S3, and the detection cycle changing unit 3 compares the output change amount of the acceleration sensors 1x to 1z with a predetermined threshold value TH, and the change amount exceeds the threshold value TH. carried out in a loop of steps S1~S9 If not treated, when the variation exceeds the threshold value TH, it performs processing of changing the detection period Ta 1 in step S10, corresponding to the detection cycle Ta1 in step S1 Set the timing.

  Here, the fact that the amount of change in the output of the acceleration sensors 1x to 1z exceeds the threshold value TH indicates that the activity meter is attached to the human body or the person wearing the activity meter has started to move. The detection period is changed in order to start the activity amount calculation, and the activity amount calculation of the calculation means 21 is started.

  As described above, when the activity meter is operating at the detection cycle Tb, the detection amount changing unit 3 monitors only the change amount of the output of the acceleration sensors 1x to 1z without performing the activity amount calculation in the calculation means 21. As a result, the processing load on the arithmetic processing unit 2 is reduced, the operation time of the arithmetic processing unit 2 is shortened, and the power consumption is reduced.

  Further, when changing from Ta1 to Tb when the detection cycle is changed, the number of consecutive times is counted using the built-in counter, but when changing from Tb to Ta1, the built-in counter is not used. This changes the period change judgment time according to the situation. In the case of Ta1 → Tb, the activity meter is not attached to the human body or the wearer wearing the activity meter is not moving, so it is judged over time, but Tb → Ta1 In this case, since the wearer wearing the activity meter starts to move, the judgment is made quickly to prevent the detection of the activity amount detection from being missed.

  Next, in the case where the activity meter is operating at the detection cycle of Ta1, if the activity amount is determined to exceed the threshold Thb by comparing the calculation result of the activity amount in step S5 with the threshold Thb, the detection is performed. The period changing unit 3 clears the count value of the built-in count (step S11).

  Then, in the next step S12, the amount of activity is compared with a preset threshold value Th1 (threshold value Thb <threshold value Th1), and when the activity amount is larger than the threshold value Th1, the count value Cta of another built-in counter is counted up. (Step S13). On the other hand, when the activity amount is smaller than the threshold value Th1, the detection cycle changing unit 3 clears the counter value Cta of another built-in counter in step S14, and returns to step S1.

  Now, the count value Cta counted up in step S13 is compared with a preset threshold value (1) (step S15), and if it is determined that the count value Cta exceeds the threshold value (1), the count value Cta continues. This means that the state in which the amount of activity is greater than the threshold value Th1 has been detected, which means that the amount of activity is large, that is, the wearer is performing intense exercise. Therefore, in order to increase the sampling rate for finer measurement, the detection cycle changing unit 3 changes the detection cycle to Ta2 in step S16 (Ta2 <Ta1 << Tb) and sets it in step S1. Here, Ta2 is about 10 to 100 Hz.

  In this way, when the amount of activity is large, the sampling rate is increased to enable high-accuracy activity amount measurement. Conversely, when the amount of activity is small, the sampling rate is slowed down to reduce current consumption. .

  As described above, in the present embodiment, by changing the period for detecting acceleration from the acceleration sensors 1x to 1z according to the amount of activity, it is possible to reduce power consumption while ensuring measurement accuracy of the amount of activity. It is.

In this embodiment, the sampling rate is changed in two stages, Ta1 and Ta2. However, when the number of stages is increased to Ta1, Ta2, Ta3,..., The same process as in the flowchart shown in FIG. It is also possible to increase the sampling rate.
(Embodiment 2)
In this embodiment, whether it is attached to the human body or not is detected from the output of the acceleration sensors 1x to 1z, and the detection cycle is changed. The circuit configuration is the same as that of the first embodiment. Therefore, refer to FIG.

  Next, the operation of this embodiment will be described with reference to the flowchart shown in FIG.

  Now, the outputs of the acceleration sensors 1x to 1z are captured by the detection means 20 of the arithmetic processing unit 2 (step S2) and detected at the constant detection cycle Ta set by the detection cycle changing unit 3 in step S1. Here, Ta is about 10 Hz to 100 Hz. Here, the detection cycle changing unit 3 detects the gravitational acceleration from the acceleration detected by the detecting means 20, and determines the direction in which the activity meter is directed vertically downward (step S3). For example, when the activity meter according to the present embodiment is attached to a human body, when the acceleration in gravity is detected in the X direction or the Z direction, the activity meter is It is determined that it is not attached to the human body but is removed and left unattended.

  Thus, when detecting that the activity meter is left unattended, the detection cycle changing unit 3 counts up the count value Ctb of the built-in counter (step S4), and proceeds to step S5. On the other hand, when gravity acceleration is detected in the Y direction and it is determined that the activity meter is attached to the human body, the count value Ctb is cleared (step S6). In step S7, the detection cycle is set to Ta.

  In step S5, the detection cycle setting unit 3 compares the count value Ctb with a preset threshold value TH, and when it is determined that the count value Ctb exceeds the threshold value TH, the activity meter is attached to the human body for a certain period of time. The detection cycle is changed to Tb (step S8). Here, Tb has a relationship of Ta> Tb, and is about 0.1 Hz to 5 Hz.

  The detection cycle is set as described above, and the calculation means 21 calculates the activity amount in step S9.

As described above, in this embodiment, when it is determined that the activity meter is not attached to the human body, the acceleration sensors 1x to 1z and the arithmetic processing unit 2 are operated by extremely slowing the sampling period of the activity meter. Time can be shortened and current consumption can be reduced.
(Embodiment 3)
In the present embodiment, as shown in FIG. 4, output composite values of the acceleration sensors 1x to 1z of the triaxial acceleration sensor unit 1 are calculated, and the composite value crosses within a predetermined time with an arbitrary threshold value set in advance. This embodiment is different from the first embodiment in that a vibration frequency measuring unit 7 that counts the number of times to be performed is provided, and the detection cycle changing unit 3 performs a detection cycle changing process based on the measured value. In the circuit configuration of FIG. 4, the same components as those of the first embodiment are denoted by the same reference numerals, and description of the configuration is omitted.

  Here, when each acceleration sensor 1x-1z is directed in the XYZ direction of the three-dimensional space that is orthogonal, the acceleration composite value obtained from the output of each acceleration sensor 1x-1z in a stationary state is equal to the gravitational acceleration of the earth. . On the other hand, although the human body moves randomly, the magnitude of the gravitational acceleration of the earth is constant at 1G, so the value of the composite value changes around 1G. For this reason, when the threshold value is about 1G, the number of times that the combined output values of the acceleration sensors 1x to 1z within a certain time cross the threshold value (about 1G) represents the speed of movement of the wearer.

  Therefore, in the present embodiment, the detection period changing unit 3 obtains the speed of movement of the wearer from the number of vibrations measured by the vibration number measuring unit 7, and the sampling rate of the acceleration sensors 1x to 1z according to the obtained speed, In other words, by setting the detection cycle, it is possible to perform sampling in accordance with the moving speed of the human body.

That is, when the number of vibrations within a certain period of time in the vibration number measuring unit 7 is large, it indicates that the speed of the human body is fast, and accordingly, the detection cycle changing unit 3 sets the detection cycle short, and conversely When the number of vibrations within a certain period of time in the vibration number measuring unit 7 is small, it indicates that the human body is operating at a low speed. Accordingly, the detection cycle changing unit 3 sets the detection cycle longer, and the set detection cycle is set to this detection cycle. A process of giving a corresponding timing signal to each means 20 and 21 of the triaxial acceleration sensor unit 1 and the arithmetic processing unit 2 is performed.

Thus, in this embodiment, by setting the detection cycle according to the speed of movement of the human body, the accuracy of acceleration detection and activity amount calculation by the detection means 20 and the calculation means 21 of the calculation processing unit 2 is increased. In addition, an activity meter with reduced power consumption in the acceleration sensors 1x to 1z and the arithmetic processing unit 2 can be realized.
(Embodiment 4)
In the present embodiment, as shown in FIG. 5, a step-up / step-down unit 8 is provided as a power source unit that supplies a power source voltage supplied to each acceleration sensor 1 x to 1 z of the three-axis acceleration sensor unit 1 by stepping up and down the voltage of the battery power source 6. This is different from the configuration of the first embodiment. In the circuit configuration of FIG. 5, the same components as those of the first embodiment are denoted by the same reference numerals, and the description of the configuration is omitted.

  Here, when the battery power supply 6 is new and the supply voltage is high, the step-up / step-down unit 8 steps down the voltage to the minimum necessary voltage at which the acceleration sensors 1x to 1z can operate and supplies the voltage to the triaxial acceleration sensor unit 1. The detection cycle changing unit 3 is operated at the detection cycle determined.

  On the other hand, when the battery power supply 6 is at the end of its life and the supply voltage is lower than the minimum necessary for the acceleration sensors 1x to 1z to be operable, the supply voltage from the battery power supply 6 is boosted and supplied to the triaxial acceleration sensor unit 1. The detection period changing unit 3 operates in the detection period set.

  In the present embodiment, the voltage of the battery power source 6 is stepped up / down by the step-up / step-down unit 8 to obtain the minimum necessary voltage at which the acceleration sensors 1x to 1z of the three-axis acceleration sensor unit 1 can always operate, whereby the acceleration sensor 1x By operating ~ 1z, power consumption can be suppressed, and even when the battery power supply 6 is in the end of life state, it can be operated to the last state.

Of course, the configuration of this embodiment may be added to the second and third embodiments.
(Embodiment 5)
In this embodiment, as shown in FIG. 6, the calculation unit 21 calculates the amplification unit 9 including amplifiers 9 x to 9 z that amplify the output signals of the acceleration sensors 1 x to 1 z and the amplification factors of the amplifiers 9 x to 9 z of the amplification unit 9. The configuration is different from that of the first embodiment in that an amplification factor setting unit 12 that is changed according to the amount of activity to be added is added. In the circuit configuration of FIG. 6, the same components as those in the first embodiment are denoted by the same reference numerals, and the description of the configuration is omitted.

  Here, since the active mass meter is driven by the battery power source 6, it cannot be operated at a high voltage in consideration of power consumption.

  Therefore, it is difficult to widen the dynamic range of the outputs of the acceleration sensors 1x to 1z.

  Therefore, in the present embodiment, it is noted that the output amplitude of the acceleration sensors 1x to 1z increases when the activity amount is large, and when the activity amount required by the computing means 21 is large, the amplification factor setting unit 12 performs the amplifier 9x of the amplification unit 9. The gain is set to be lowered by ˜9z, and when the amount of activity is small, the gain setting unit 12 is set to raise the gain. In this way, in the calculation of the amount of activity when the amount of activity is small, the small amount of activity detection capability is achieved up to the performance of the acceleration sensor depending on the S / N ratio of the acceleration sensor regardless of the dynamic range of the acceleration sensors 1x to 1z. A high-performance activity meter can be realized.

  Of course, the configuration of the present embodiment may be added to the second to fourth embodiments.

1 is a circuit configuration diagram of Embodiment 1. FIG. 3 is a flowchart for explaining the operation of the first embodiment. 6 is a flowchart for explaining operations of the second embodiment. 6 is a circuit configuration diagram of Embodiment 3. FIG. FIG. 6 is a circuit configuration diagram of a fourth embodiment. FIG. 9 is a circuit configuration diagram of a fifth embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 3 axis | shaft acceleration sensor part 1x-1z Acceleration sensor 2 Operation processing part 20 Detection means 21 Calculation means 3 Detection period change part 4 Display part 5 Memory | storage part 6 Battery power supply

Claims (5)

An acceleration sensor; detection means for periodically detecting acceleration based on the output of the acceleration sensor; and calculation means for calculating exercise intensity as an activity amount based on the detected acceleration of the detection means. A detection period changing means for changing the period based on an acceleration or an amount of activity calculated by the calculating means, wherein the detection time for the detection period changing means to determine the period change is determined by the detection acceleration or the activity of the detecting means; An activity meter characterized in that it is changed so that the amount of change per hour is short when the amount of change is large and long when it is small . The period change by the detection period changing means shortens the period when the detected acceleration of the detecting means or the amount of activity calculated by the calculating means is larger than a predetermined value, and the detected acceleration or the amount of activity is smaller than the predetermined value. 2. The activity meter according to claim 1 , wherein the period is sometimes lengthened . 3. The detection cycle changing means according to claim 1 or 2, wherein when the period is lengthened, the determination is made based on the magnitude of the activity amount, and when the detection period is shortened, the magnitude of the detected acceleration of the detection means is determined. Activity meter. Measuring means for measuring the number of vibrations per fixed time from the detected acceleration of the detection means, wherein the detection period changing means changes the detection period according to the number of vibrations measured by the measuring means. The activity meter according to claim 1 . The activity meter according to any one of claims 1 to 4, further comprising a power supply unit that supplies a necessary minimum voltage at which the acceleration sensor can operate according to the detection period .

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