JP4706310B2 - Pedometer - Google Patents

Description

  The present invention relates to a pedometer.

2. Description of the Related Art Conventionally, a pedometer that can be measured without being attached to a belt and put in a pocket or the like has been provided (for example, Patent Document 1). This pedometer uses a combination of a plurality of acceleration sensors and an angle detection sensor to select an output signal of the acceleration sensor corresponding to the orientation of the main body detected by the angle sensor, and among the plurality of acceleration sensors, A method of taking out vibration output with large vibration is adopted.
JP-A-9-223214 (paragraph numbers 0018, 0038)

  By the way, in the configuration of the pedometer disclosed in the above-mentioned Patent Document 1, even when the same acceleration is given depending on the direction of the pedometer, the output value of the acceleration sensor differs, so the acceleration sensor corresponding to the selected direction. There is a problem that accurate counting cannot be performed only by counting the number of steps in which the output value is equal to or greater than a predetermined value as the number of steps.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a pedometer which improves the counting accuracy of the number of steps and has little change in accuracy depending on the direction.

In order to achieve the above object, according to the first aspect of the present invention, a composite value of the triaxial acceleration sensor and the triaxial acceleration value output from the triaxial acceleration sensor is calculated and the magnitude of the composite value is calculated. the basis of the number of steps calculation means for calculating the number of steps, the step count calculation unloading by step number calculating means by determining whether the amount of acceleration change exceeds the threshold value is compared with a predetermined threshold value and the acceleration change amount in the traveling direction Yes / And a means for determining nothing.

According to the invention of claim 1, by using a composite value of the acceleration values of the three axes, the number of steps can be accurately counted regardless of the direction of the pedometer, and only the output value in one direction Compared with the case where the number of steps is counted, the change in accuracy is small. Further, according to the invention of claim 1, by distinguishing upper and lower operation and the walking and in place, it is possible to improve the counting accuracy of the number of steps.

In the invention of claim 2 , a three-axis acceleration sensor and a step number calculating means for calculating a combined value of the three-axis acceleration values output from the three-axis acceleration sensor and calculating the number of steps based on the magnitude of the combined value And any one of the average value, standard deviation, and variance of the composite value for a certain period of time and a predetermined threshold value corresponding to the calculated value, the calculated value exceeds the threshold value and the traveling direction or acceleration variation exceeds a predetermined threshold, characterized in that it comprises a means for determining the presence / absence of the number of steps calculated by the step number calculating means by whether or not.

According to the invention of claim 2, by using the composite value of the acceleration values of the three axes, it is possible to accurately count the number of steps regardless of the direction of the pedometer, and only the output value in one direction Compared with the case where the number of steps is counted, the change in accuracy is small. Further, according to the invention of claim 2, it is possible to increase the and step counting accuracy of eliminating counting errors of the step count of the predetermined period.

In the invention of claim 3, calculated in the invention of claim 1 or 2, a walking speed based on the time difference between the first step and the last step of a predetermined unit number of steps and the predetermined measures the number of steps calculated by the step number calculating means It is characterized by having a calculating means.

According to the invention of claim 3 , it is possible to provide a pedometer having a walking speed measuring function.

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the period of time of the step count calculating means sampling and capturing the output of the triaxial acceleration sensor is equal to or greater than a predetermined value indicating that the walking is in progress. The sampling period when the output value is less than the predetermined value is longer than the period of the case.

According to the invention of claim 4 , by increasing the sampling period of the triaxial acceleration sensor when not walking, the power consumption of the triaxial acceleration sensor is reduced and the calculation load of the step count calculating means is reduced. Therefore, the power consumption required for the calculation can be reduced, and as a result, battery consumption can be reduced when a battery is used as the power source.

According to a fifth aspect of the invention, there is provided a user interface according to any one of the first to fourth aspects of the present invention, which has a user interface that takes in operation information according to the magnitude and direction of acceleration of the three-axis acceleration sensor.

According to the fifth aspect of the present invention, the operation input can be performed by shaking the pedometer by hand. Therefore, there is no need to provide an operation input unit using the operation button, and the operation button is limited by the size limit. Therefore, the pedometer can be reduced in size, and the three-axis acceleration sensor can be used as a signal source for operation information, so that the cost does not increase.

  In the present invention, by using a composite value of three-axis acceleration values, the number of steps can be accurately counted regardless of the direction of the pedometer, and the number of steps is counted only with an output value in one direction. Compared to the case, there is an effect that the change in accuracy is small.

Embodiments of the present invention will be described below.
(Embodiment 1)
In the present embodiment, a display device such as a liquid crystal display for displaying information including a triaxial acceleration sensor 1, an arithmetic processing unit 2 including a microcomputer, a memory unit 3, a battery power supply 4, and the number of steps. 5 and an operation input unit 6 including a set of push buttons for setting and operation. The pedometer main body H includes a triaxial acceleration sensor 1, an arithmetic processing unit 2, a memory unit 3, and a battery power source 4. The display 5 is mounted on the pedometer main body H so that the display surface faces the outside, and the operation input unit 6 is mounted on the pedometer main body H so that the push button can be operated from the outside.

  The arithmetic processing unit 2 samples the triaxial acceleration values output from the triaxial acceleration sensor 1 at a predetermined period, and calculates a step count calculating means for calculating a composite value of the triaxial acceleration values for each sampling and counting the number of steps. 20 and control processing means 21 for controlling the display 4, processing the operation information of the operation input unit 6, and controlling the reading and writing of the memory unit 3 are realized by software as a basic function of the pedometer.

Here, the step count calculating means 20 includes a composite value calculation function 20a for calculating the square root of the composite value of the triaxial acceleration values and a step count counting function 20b for counting the number of steps based on the calculated square root of the composite value. each axis X which is output from the combined value calculation function 20a is 3-axis acceleration sensor 1, Y, when the value of the acceleration in the Z was _{a x, a y, a z} , synthesized acceleration values, that is, the composite value a It calculates based on the following formula | equation (1).

A = a _x ² + a _y ² + a _z ² (1)
Thus, for example, when the triaxial acceleration sensor 1 can detect a DC component, the gravitational acceleration 1G is always obtained as the composite value A when the pedometer is stationary. Further, even when not stationary, 1G is always included in the composite value A as a direct current component.

  Therefore, the value of the square root of the composite value A is the magnitude of acceleration received by the pedometer including gravitational acceleration, and this magnitude does not depend on the direction of the pedometer. That is, it is possible to accurately calculate the number of steps regardless of the orientation of the pedometer.

  Thus, in the step count function 20 that takes in the square root value of the composite value A calculated by the composite value calculation function 20a of the step count calculation means 20, the threshold value T2 registered in the memory unit 3 in advance for the step count calculation is combined. The square root value of the value A is compared, and if the square root value of the composite value A exceeds the threshold value T1, a process of counting one step and integrating the counted value is performed, and the integrated value at that time is controlled as step count data The data is sent to the processing means 21.

  In order to simplify the calculation in the composite value calculation function 20a, the composite value A without taking the square root may be used as it is.

  The control processing means 21 performs a process for displaying the step count data sent from the step count calculation means 20 on the display unit 4 and sends the display data to the display unit 4 so that the display value is changed to the integrated value. In response, the current step count is presented to the person being measured by updating and displaying them momentarily.

  The counted number of steps is accumulated and stored in the memory unit 3 so that the total number of steps can be confirmed on a weekly or monthly basis.

The operation input unit 6 is necessary as a pedometer for starting / stopping step measurement, resetting the accumulated step count, and displaying the number of steps from the start of the step measurement to the present and displaying the accumulated step count. The operated input information is taken into the control processing means 21, and the display 5 is controlled and the memory unit 3 is read / written.
(Embodiment 2)
By the way, the vibration is transmitted to the pedometer even when the operated person wears or carries the pedometer but is not walking (for example, when riding on a train), and the triaxial acceleration sensor 1 is thereby transmitted. There is a possibility that the number-of-steps calculation means 20 counts the number of steps based on the output acceleration composite value A.

  Therefore, in order not to perform step count counting when instantaneous acceleration is detected or an acceleration value above a certain level is not shown by a slight movement, the above-described composite value A as shown in FIG. An average value (or variance value or standard deviation value) for a certain period of time is calculated, and the calculated result is compared with a threshold value T2 registered in advance in the memory unit 3. If the calculated result is not greater than or equal to the threshold value T2, walking is performed. The walking determination function 20c is provided to instruct the step counting function 20b to stop the step counting based on the comparison between the square root value of the composite value A and the threshold value T1, that is, to perform the process of eliminating the step counting. There is a feature in the added point.

  Thus, in the present embodiment, when the average value (or variance value or standard deviation value) of the composite value A for a certain period is less than the threshold value T2, the number of steps is not counted, thereby reducing the counting error of the number of steps in the period. Will be able to.

  Since other configurations are the same as those in the first embodiment, the illustration and description are omitted here with reference to the configuration of the first embodiment and the description thereof.

Instead of the above-described walking determination function 20c, the acceleration in the front-rear direction hardly occurs when the measurement subject moves up and down at the fixed position, but when walking, the direction of travel is added in addition to the vertical movement. Since the acceleration changes in accordance with the walking cycle, a walking determination function for determining whether or not the walking is performed by detecting a change in the acceleration value of each axis of the triaxial acceleration sensor 1 may be used. The step counting function 20b may be used to count the number of steps only when the walking determination function and the above-described walking determination function 20c are used in combination, and both of the functions are determined to be walking. Can be increased.
(Embodiment 3)
If the number of steps can be counted, the walking speed can be calculated. For example, the time when counting one step and the time when counting next step are sampled from the acceleration detection signal of the triaxial acceleration sensor 1. The walking speed can be calculated by dividing the preset step length of the person to be measured by the time interval between the time when the next step is counted and the time saved earlier, Yes, but when there is a counting error, the error increases.

  In this embodiment, walking speed measuring means for measuring a walking speed in which an error due to a counting error is unlikely to occur is added to the pedometer of the first or second embodiment.

  FIG. 3 shows a functional configuration of the present embodiment. In the first embodiment (or the second embodiment), the first embodiment (or the second embodiment) is the same as the first embodiment (or the second embodiment) in that a walking speed measuring means 22 is added to the arithmetic processing unit 2. It is different from 2).

  In other words, in this embodiment, the walking speed measuring means 22 provided with the above-mentioned steps other than the counting function eliminates the error by dividing the number of steps by a fixed unit number of steps, the step length, and the time interval between the first step and the last step. As shown in the following formula (2), n steps are set as the unit number of steps, and the time difference between the time of the first step and the time of the last step is set as a predetermined step length × step number (n− By dividing 1), the average walking speed S of n steps is calculated. Note that n steps are at least 3 or more, and 10 steps or more are desirable to reduce the error.

S = (number of steps (n−1) × step length) / (time of last step−time of first step) (2)
As described above, in this embodiment, in addition to the function as a pedometer, it can also function as a walking speed meter. The measured walking speed is displayed along with the number of steps on the display 5 under the control of the control processing means 21. Of course, switching display may be performed by operating the operation input unit 6.
(Embodiment 4)
By the way, when calculating the number of steps, the peak value of the triaxial acceleration value of the triaxial acceleration sensor 1 is detected. Therefore, when the walking cycle is 2 to 3 Hz, the acceleration value is at least at a sampling cycle (sampling frequency) of 6 Hz or more. Must be sampled.

  On the other hand, when the sampling frequency is increased, a large amount of electric power is consumed due to the supply of power to the triaxial acceleration sensor 1 and the increase in the amount of calculation in the arithmetic processing unit 2.

  Therefore, in the present embodiment, in order to reduce power consumption, when the acceleration value of the triaxial acceleration sensor 1 is less than a predetermined value, the step count calculation means 20 performs sampling sufficient to detect whether or not the pedometer is moved. Acceleration values are taken in at a cycle (1 Hz to 0.2 Hz), and if the pedometer is moved even a little (when acceleration is detected), the step count calculation means 20 samples it to return to the original sampling cycle (for example, 6 Hz). It has a variable frequency function.

  Thus, in this embodiment, it is possible to realize a pedometer with low power consumption while ensuring accuracy.

  Since other configurations may be any of the configurations of the first to third embodiments, illustration and description thereof are omitted here.

(Embodiment 5)
In general, since the pedometer is made small in consideration of carrying, there is a problem that the operation button of the input operation unit 6 is small and difficult to operate.

  On the other hand, when using a pedometer, it is worn on the subject's belt or put in a pocket, etc., but in this case the pedometer's orientation changes little and is constant when the subject is walking. It is characterized by continuously detecting acceleration within a certain range having substantially the same period in the direction.

  In the present embodiment, the direction of the pedometer main body H is changed by hand or shaken by using the above feature, and the operation button can be operated instead.

  That is, in this embodiment, as shown in FIG. 5, an operation determination unit 23 that captures the output of the triaxial acceleration sensor 1 is provided, and a user interface is configured together with the triaxial acceleration sensor 1. Since other configurations may be any of the configurations of the first to fourth embodiments, illustration and description of the overall configuration are omitted.

  Here, when the operation input unit is provided with six operation buttons, the six operation inputs are distributed to each surface of the hexahedral pedometer main body H, and the operation that can operate the surface number facing the upward direction of gravity is performed. Input. That is, the operation discriminating means 23 discriminates the direction (surface number) of the pedometer main body H from the output of each axis of the triaxial acceleration sensor 1 and assigns it to the surface number from the pattern to be further shaken and the output size. Operation information associated with the pattern and the output size is generated and output to the control processing means 21. For example, when the surface number is directed upward, the control information corresponding to the one-shot operation of the push button is increased, the strength of the shake is increased, and the interval of the second shake is shortened. In this case, predetermined operation information is output from the output of the triaxial acceleration sensor 1 so that operation information corresponding to a long press operation of the push button is generated.

  Thus, in this embodiment, when the measurement subject performs an operation input, the pedometer body H is held by hand and the surface having the surface number corresponding to the desired operation input is directed upward with respect to the direction of gravity. A desired operation input can be performed by shaking in a predetermined pattern.

1 is an overall configuration diagram of Embodiment 1. FIG. It is a block diagram of the walk calculation means used for Embodiment 2. FIG. 6 is an overall configuration diagram of Embodiment 3. FIG. 10 is an explanatory diagram of a relationship between a surface number and a pedometer main body according to a fifth embodiment. FIG. 10 is a configuration diagram of a main part of a fifth embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 3 axis | shaft acceleration sensor 2 Arithmetic processing unit 20 Step count calculation means 20a Composite value calculation function 20b Step count count function 21 Control processing means 3 Memory part 4 Battery power supply 5 Display 6 Operation input part

Claims (5)

3 and axis acceleration sensor, a step number calculating means for calculating the number of steps based on the size of the resultant value to calculate the composite value of the acceleration values of the three axes output from the triaxial acceleration sensor, the acceleration in the direction of the motion variation A pedometer comprising: a means for comparing the amount with a predetermined threshold value and determining whether or not the number of steps calculated by the step number calculating means is based on whether or not the acceleration fluctuation amount exceeds the threshold value. . A three-axis acceleration sensor; a step number calculating means for calculating a step value based on a magnitude of the three-axis acceleration value output from the three-axis acceleration sensor; Comparing the calculated value of any one of the average, standard deviation, and variance with a predetermined threshold corresponding to the calculated value, the calculated value exceeds the threshold and the acceleration fluctuation amount in the traveling direction is determined in advance. It was either exceeds the threshold, whether the step number meter you characterized by comprising a means for determining the presence / absence of the number of steps calculated by the step number calculating means. Claim 1 or, characterized in that it comprises a calculating means for calculating a walking speed based on the time difference between the first step and the last step of a predetermined unit number of steps and the predetermined measures the number of steps calculated by the step number calculating means The pedometer according to 2 . The cycle in which the step count calculation means samples and captures the output of the triaxial acceleration sensor is longer than the cycle when the output value is equal to or greater than a predetermined value indicating that walking is in progress, and the sampling cycle when the output value is less than the predetermined value is longer. pedometer according to any one of claims 1 to 3, characterized in that. The pedometer according to any one of claims 1 to 4, further comprising a user interface that captures operation information based on an acceleration magnitude and direction of the three-axis acceleration sensor .

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