JP5561028B2 - Step counting device - Google Patents

Description

  The present invention relates to a step count measuring device built in a mobile phone or the like.

  Some mobile phones have a function as a step counting device that measures the number of steps of a mobile phone user in addition to the original functions of the mobile phone. A mobile phone having a function as a step counting device includes an acceleration sensor that detects an acceleration generated in the mobile phone by the walk of the mobile phone, a circuit that detects a walk of the mobile phone using an output signal of the acceleration sensor, and the like Is built-in. For this reason, a mobile phone having a function as a step count measuring device consumes more power than a mobile phone that does not. Patent Documents 1 and 2 disclose techniques for suppressing the power consumption of this type of mobile phone.

  The mobile phone disclosed in Patent Document 1 includes an acceleration sensor and a measurement unit in addition to a control unit that serves as a control center of the mobile phone. The acceleration sensor outputs an acceleration value indicating the acceleration generated in the mobile phone. The measurement unit analyzes the waveform of the acceleration value output from the acceleration sensor, determines whether or not the walking pattern has continued for a predetermined time, and when the determination result is affirmative, the step count measurement is performed. Start operation. When the notification of the number of steps from the measurement unit stops for a predetermined time (for example, 5 seconds), the control unit stops the process of measuring the number of steps in the measurement unit. According to this technique, power consumption can be suppressed compared to a case where the measurement unit always operates.

  The mobile phone disclosed in Patent Document 2 includes an acceleration sensor in addition to a control unit that serves as a control center of the mobile phone. This acceleration sensor has a built-in counter. The acceleration sensor considers that the mobile phone user has walked when the acceleration generated in the mobile phone exceeds a predetermined reference value, and counts up the count data in the counter. In addition, the control unit transitions between the activated state and the Sleep state that consumes less power than the activated state, and reads count data in the counter in the acceleration sensor each time the activated state is reached. And a control part updates the step count in the memory | storage part in the said control part with this count data, and displays the updated step count on a main display. According to this technique, power consumption can be suppressed as compared with a case where the number of steps is measured while the control unit is in an activated state.

JP 2010-15414 A JP 2009-300369 A

However, in the technique of Patent Document 1, since it is determined whether or not the walking pattern has continued for a predetermined time or more in order to determine whether or not to transition from the sleep state to the activated state, in the sleep state There is a problem that the amount of calculation of the measurement unit is large and it is difficult to sufficiently reduce the power consumption of the measurement unit in the sleep state. Moreover, in the technique of patent document 1, when the walking pattern continues for a predetermined time in the sleep state, the transition to the normal mode for measuring the number of steps is made, so that the step number measurement is started after the wearer starts walking. There is a problem that the latency becomes long and the step count measurement becomes inaccurate. In the technique of Patent Document 2, since it is necessary to always operate an acceleration sensor with a built-in counter, even if the power consumption of the control unit can be reduced by intermittently driving the control unit, the acceleration sensor And there exists a problem that the power consumption as the whole control part cannot be reduced.
The present invention has been devised under such a background, and an object thereof is to suppress power consumption while ensuring the accuracy of the step count measurement in the step count measuring device incorporated in the mobile phone. .

  The present invention has two states, an acceleration sensor that outputs an acceleration value indicating acceleration, and a standby state and a measurement state. In the standby state, the acceleration value is acquired from the acceleration sensor, and the acquired acceleration value and threshold value In the measurement state, the acceleration value is acquired from the acceleration sensor and the predetermined number of acceleration values acquired up to the present are repeated. It repeats the determination of one-step walking using, the counting of the number of steps according to the determination result, the determination of the possibility of transition to the standby state based on the predetermined number of acceleration values acquired up to now, and the standby for a fixed time Provided is a step count measuring device comprising a control means.

  According to this invention, in the standby state, the control means determines whether or not to transit to the measurement state only by determining whether or not the acceleration value acquired from the acceleration sensor exceeds a threshold value. Therefore, in the standby state, the time required for processing other than the standby for a certain time can be shortened, and the power consumption of the control means can be reduced. In addition, even if the step count measuring device does not walk one step, even if the acceleration value exceeds the threshold value and the transition to the measurement state occurs, in the measurement state, the predetermined number of accelerations acquired so far Since it is determined based on the value whether or not the carrier of the step counting device has taken one step, it is possible to prevent erroneous step counting. Therefore, according to the present invention, it is possible to suppress the power consumption of the step count measuring device while ensuring the accuracy of the step count measurement.

It is a figure which shows the structure of the mobile telephone containing the step count measuring apparatus which is one Embodiment of this invention. It is a perspective view which shows the external appearance of the mobile phone. It is a figure which shows the state transition of the host CPU shown in FIG. It is a figure which shows the state transition of MCU shown in FIG. It is a flowchart which shows operation | movement of MCU shown in FIG. It is a timing chart which shows operation | movement of MCU and an acceleration sensor shown in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing an electrical configuration of a mobile phone 10 including a step count measuring device 40 according to an embodiment of the present invention. FIG. 2 is a perspective view showing an appearance of the telephone 10. As shown in FIG. 2, the mobile phone 10 includes a casing 21 and a casing 22 and a hinge member 23 that couples the casing 21 and the casing 22 so that they can tilt with respect to each other. A speaker 25 and a display 26 are provided on the surface 24 of the housing 21. An operation key 28 and a microphone 29 are provided on the surface 27 of the housing 22. The housing 22 includes a host CPU 31, a RAM 32, a ROM 33, an open / close sensor 34, a wireless unit 35, a key sensor 36, a sound processing unit 37, a display processing unit 38, and a step count measuring device 40, and the portable device. A battery 60 which is a power supply source in the telephone 10 is incorporated.

  The host CPU 31 is a device that serves as a control center of the mobile phone 10. As shown in FIG. 3, the host CPU 31 transitions between two states, a standby state and an activated state. The host CPU 31 performs the following processing in each state. In the standby state, the host CPU 31 monitors the occurrence of an event EV-active that is a condition for transition from the standby state to the activated state. In the event EV-active, which is a condition for transition from the standby state to the activated state, the fact that the opening / closing sensor 34 detects the tilt of the casing 21 in the direction away from the casing 22 (Y direction in FIG. 2). An event indicating that the wireless unit 35 has received an incoming call signal, a vent indicating that the key sensor 36 has detected that the operation key 28 has been pressed, and the like. In the standby state, when the event EV-active has not occurred, the host CPU 31 repeats the process of starting after pausing until the time T1 elapses and monitoring the occurrence of the event EV-active. When the event EV-active occurs, the host CPU 31 transitions to the activated state.

In the activated state, the host CPU 31 reads the application program stored in the ROM 33 into the RAM 32 in accordance with the operation of the operation key 28. The host CPU 31 controls the sound processing unit 37 and the display processing unit 38 according to the application program read out to the RAM 32. The audio processing unit 37 performs processing for mediating transmission / reception of sound signals between the speaker 25 and the microphone 29 and the host CPU 31 under the control of the host CPU 31. The display processing unit 38 performs processing for displaying an image on the display 26 under the control of the host CPU 31. The application program stored in the ROM 33 includes a call application for making a call with another mobile phone 10 and an HTML (Hyper Text Markup in WWW (World Wide Web).
Language) In addition to a browsing application that receives data and displays the contents on the display 26, a pedometer that is an application program that acquires the number of steps Num, which is the processing result of the step count measuring device 40, from the device 40 and displays it on the display 26 There is an application.

  In the activated state, the host CPU 31 monitors the occurrence of an event EV-wait which is a condition for transition from the activated state to the standby state. In the event EV-wait, which is a condition for transition from the start state to the standby state, it is detected that the opening / closing sensor 34 has detected the tilt of the casing 21 in the direction approaching the casing 22 (X direction in FIG. 2). And an event indicating that any operation key 28 has not been pressed over time T2 (T2 <T1). When the event EV-wait occurs, the host CPU 31 transitions to the standby state.

In FIG. 1, the step count measuring device 40 includes an acceleration sensor 44, an MCU (Micro Control Unit) 41, a RAM 42, and a ROM 43. The acceleration sensor 44 is connected to the MCU 41 by an I ² C (Inter-Integrated Circuit) bus. The acceleration sensor 44 is a device that outputs an acceleration value indicating the acceleration generated in the acceleration sensor 44 under the control of the MCU 41. More specifically, when the MCU 41 starts power supply to the acceleration sensor 44 and gives an activation instruction signal to the acceleration sensor 44 via the I ² C bus, the acceleration sensor 44 detects the acceleration generated in the acceleration sensor 44. the component _a X of the three axes directions perpendicular to each _other, a Y, and decomposed into _{a Z} samples, substituting the components _{a X, a Y, a Z} sample _{DA X,} DA Y, the DA _Z in the formula The acceleration value data DA obtained in this way is supplied to the MCU 41 via the I ² C bus.
DA = (DA _X ² + DA _Y ² + DA _Z ² ) ^1/2 (1)

The MCU 41 is a control center of the step count measuring device 40. The MCU 41 executes the step count measurement program stored in the ROM 43 while using the RAM 42 as a work area. As illustrated in FIG. 4, the MCU 41 transitions between two states of a standby state and a measurement state according to the step count measurement program. FIG. 5 is a flowchart showing the processing contents of the step count measurement program executed by the MCU 41. In the present embodiment, when the MCU 41 is activated, the MCU 41 enters a standby state (S101). In the standby state, the MCU 41 causes the acceleration sensor 44 to intermittently supply power every time T3 (for example, T3 = 200 milliseconds), acquires acceleration value data DA from the acceleration sensor 44, Based on the magnitude relationship between the acceleration value data DA and the threshold value TH1 (the threshold value TH1 is a value slightly larger than the gravitational acceleration (9.8 m / s ² )), it is determined whether or not transition to the measurement state is possible. More specifically, the MCU 41 performs the following process in the standby state.

  First, the MCU 41 supplies power to the acceleration sensor 44 (S102). Next, the MCU 41 acquires acceleration value data DA from the acceleration sensor 44 (S103).

  Next, the MCU 41 performs an operation determination process (S104). The operation determination process is a process of determining whether or not the mobile phone 10 is moving. In the motion determination process, the MCU 41 compares the acceleration value data DA acquired in step S103 with the threshold value TH1. When the acceleration value data DA exceeds the threshold value TH1, it is considered that the mobile phone 10 is moving, and when the acceleration value data DA does not exceed the threshold value TH1, the mobile phone 10 is considered to be stationary.

  When the MCU 41 determines in step S104 that the acceleration value data DA does not exceed the threshold value TH1 (S104: No), the MCU 41 stops the power supply to the acceleration sensor 44 (S105). Thus, by stopping the power supply to the acceleration sensor 44, the battery 60 is not consumed by the acceleration sensor 44. The MCU 41 waits until the time T3 has elapsed after stopping the acceleration sensor 44 (S106). The MCU 41 determines whether an operation for instructing the end of the step count measurement has been performed after the time T3 has elapsed (S107). When the operation for instructing the end of the step count measurement is not performed (S107: No), the MCU 41 returns to step S102 to activate the acceleration sensor 44 and repeats the subsequent processing. Further, when an operation for instructing the end of the step count measurement is performed (S107: Yes), the MCU 41 ends all the processes.

  When the MCU 41 determines in step S104 that the acceleration value data DA exceeds the threshold value TH1 (S104: Yes), the MCU 41 transits to the measurement state (S201). In the measurement state, the MCU 41 acquires acceleration value data DA output from the sensor 44 while continuing to supply power to the acceleration sensor 44, and determines one-step walking using the past predetermined number of acceleration value data DA. The number of steps Num corresponding to the determination result is counted, and the stationary determination that is the determination as to whether or not the transition to the standby state is possible, and the standby is performed when it is determined by the stationary determination that the mobile phone 10 is stationary. Transition to the state. More specifically, the MCU 41 performs the following processing in the measurement state.

  First, the MCU 41 acquires acceleration value data DA output from the acceleration sensor 44 (S202), and writes the acquired acceleration value data DA into the ring buffer in the RAM.

  Next, the MCU 41 performs a step count measurement process (S203). In the step count measurement process, it is determined whether or not a single step has been taken by the wearer using a predetermined number of past acceleration value data DA written in the ring buffer in the RAM 42. This is a process for counting up Num. More specifically, in the step count measurement process, the MCU 41 scans the past predetermined number of acceleration value data DA in the ring buffer, and when a peak appears in the waveform of the acceleration value data DA (more specifically, When the magnitude of the acceleration value data DA has changed from rising to falling), it is considered that one step has been taken by the wearer, and the number of steps Num in the RAM 42 is counted up by one.

  The MCU 41 performs stillness determination processing (S204). The stillness determination process is a process for determining whether or not the carrier is stationary. In the stillness determination process, the MCU 41 compares the latest predetermined number of acceleration value data DA written in the ring buffer of the RAM 42 with the threshold value TH1. When all of the latest predetermined number of acceleration value data DA are below the threshold value TH1, it is considered that the mobile phone 10 is stationary, and when it is not below the threshold value TH1, the mobile phone 10 is still moving. I reckon.

  If the MCU 41 determines in step S204 that the mobile phone 10 is stationary (S204: Yes), the MCU 41 transits to a standby state. On the other hand, if the MCU 41 determines in step S204 that the mobile phone 10 is not stationary (S204: No), the MCU 41 waits until time T4 (T4 <T3: T4 = 40 milliseconds, for example) elapses. (S205). Then, after the time T4 has elapsed, the MCU 41 determines whether an operation for instructing the end of the step count measurement has been performed (S206). When the operation for instructing the end of the step count measurement is not performed (S206: No), the MCU 41 returns to step S202 to acquire the latest acceleration value data DA output from the acceleration sensor 44, and thereafter Repeat the process. In addition, when an operation for instructing the end of the step count measurement by the step count measuring device 40 is performed (S206: Yes), the MCU 41 ends all the processes.

  The waiting time T4 in step S205 hinders the determination of whether or not the step of measuring the acceleration value determined by the total required time in steps S202 to S205 has taken one step in the step counting process. It is determined so as to have a sufficiently short period that does not occur. That is, when the acceleration value capturing period that does not hinder the determination of whether or not one step of walking has been performed is T2, the time obtained by subtracting the time required for the processing of steps S202 to S204 from this period T2 This is the waiting time T4 in step S205. On the other hand, in the standby state, it is not determined whether or not one step of walking has been performed, but merely determines whether or not the acceleration value exceeds the threshold value. Therefore, the acceleration period acquisition period T1 in the standby state is: It is not necessary to be the same as the period T2 for acquiring the acceleration value in the measurement state. In the present embodiment, in order to reduce power consumption in the standby state as much as possible, the acceleration value acquisition cycle T1 in the standby state is made longer than the acceleration value acquisition cycle T2 in the measurement state. The time obtained by subtracting the time required for the processing in steps S102 to S105 from the acceleration value acquisition cycle T1 in this standby state is the standby time in step S106.

  In the present embodiment described above, as shown in FIG. 6A, the MCU 41 activates the acceleration sensor 44 (S102), acquires acceleration value data DA in the acceleration sensor 44 (S103), and determines the operation in the standby state. A series of processes (S104) and stop of the acceleration sensor 44 (S105) are performed intermittently with a pause of time T3. As shown in FIG. 6B, in the measurement state, the MCU 41 performs a series of acquisition of acceleration value data DA in the acceleration sensor 44 (S202), step count measurement process (S203), and stillness determination process (S204). The process is intermittently performed with a pause at time T4. Here, in the measurement state, the step count measurement process (step S203) requires a large amount of computation, and therefore the overall time required for steps S202 to S204 becomes long. On the other hand, in the standby state, it is determined whether or not to transit to the measurement state only by determining whether or not the acceleration value data DA output immediately after the acceleration sensor 44 is activated exceeds the threshold value TH1. The time required for all the processes from steps S102 to S105 is short.

  Therefore, the time T1-T3 in which the MCU 41 executes processing in the standby state is shorter than the time T2-T4 in which the MCU 41 executes processing in the measurement state. Therefore, the power consumption of the MCU 41 in the standby state can be reduced. Moreover, in the present embodiment, the acceleration value acquisition period T1 in the standby state can be made longer than the acceleration value acquisition period T2 in the measurement state. Therefore, according to this embodiment, the power consumption of the step count measuring device 40 can be suppressed.

  Further, in the present embodiment, when the acceleration value data DA exceeds the threshold value TH1 in the standby state, the state immediately transitions to the measurement state, so the latency from the start of walking by the wearer to the start of step count measurement is shortened. For example, a latency of about 200 ms can be realized. Then, when the acceleration value data DA exceeds the threshold value TH1 and transitions to the measurement state, in the measurement state, it is determined whether or not a single step by the wearer has been performed based on the past predetermined number of acceleration value data DA. Done. For this reason, when the wearer actually starts walking, the count of the number of steps is not missed.

  On the other hand, when the mobile phone makes a transition to the measurement state even though the user is not walking, the number of steps is not erroneously counted in the measurement state. Therefore, according to the present embodiment, the power consumption of the step count measuring device 40 can be suppressed while sufficiently shortening the latency until the start of step count measurement and ensuring the accuracy of the step count measurement.

  In the present embodiment, since the acceleration value data DA is periodically acquired from the acceleration sensor 44 while the power supply to the acceleration sensor 44 is continued in the measurement state, the operation of the acceleration sensor 44 is stabilized. In this state, the acceleration value data DA can be acquired at a sufficiently short period necessary for measurement accuracy, and the step count can be accurately performed.

  On the other hand, in the standby state, the acceleration sensor 44 is intermittently supplied with power, and the acceleration value data DA is acquired from the acceleration sensor 44 during a period in which the acceleration sensor 44 is supplied with power. Power consumption can be reduced. In this case, the acceleration value data DA acquired from the acceleration sensor 44 in the standby state is used to determine whether or not the transition from the standby state to the measurement state is performed, and acceleration waveform analysis for counting the number of steps is performed. Therefore, even if the accuracy of the acceleration value data DA is decreased by intermittently driving the acceleration sensor 44, there is no adverse effect.

  Although one embodiment of the present invention has been described above, the present invention may have other embodiments. For example, in the above embodiment, the acceleration value data DA is compared with the common threshold value TH1 in the motion determination process in the standby state (S104) and the stillness determination process in the measurement state (S204). However, the threshold value compared with the acceleration value data DA in the motion determination process may be different from the threshold value compared with the acceleration value data DA in the stillness determination process.

DESCRIPTION OF SYMBOLS 10 ... Mobile phone, 21, 22 ... Housing, 23 ... Hinge, 24, 27 ... Surface, 25 ... Speaker, 26 ... Display, 28 ... Operation key, 29 ... Microphone, 31 ... Host CPU, 32 ... RAM, 33 ... ROM, 34 ... Open / close sensor, 35 ... Wireless unit, 36 ... Key sensor, 37 ... Audio processing unit, 38 ... Display processing unit, 40 ... Step count measuring device, 41 ... MCU, 42 ... RAM, 43 ... ROM, 44 ... Acceleration sensor .

Claims (3)

An acceleration sensor that outputs an acceleration value indicating acceleration;
A buffer memory for storing a predetermined number of acceleration values;
There are two states, a standby state and a measurement state. In the standby state, acquisition of an acceleration value from the acceleration sensor, determination of whether or not to change to the measurement state based on the magnitude of the acquired acceleration value , and a certain period of time In the measurement state, the acceleration value is acquired from the acceleration sensor, the acquired acceleration value is written to the buffer memory, and a predetermined number of acceleration values written to the buffer memory so far Judgment of one-step walking using, and counting of the number of steps according to the determination result, and when all of the predetermined number of acceleration values written in the buffer memory up to now are below a predetermined threshold value A step count measuring apparatus comprising: a control unit that repeats a stationary determination to make a transition to and a standby for a predetermined time.   2. The step counting apparatus according to claim 1, wherein in the standby state, the control unit stops power supply to the acceleration sensor during the standby for the predetermined time.   The step count measuring apparatus according to claim 1 or 2, wherein a cycle of acquiring the acceleration value in the standby state is longer than a cycle of acquiring the acceleration value in the measuring state.

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