JP2014049784A - Pulse gap estimation device, pulse gap estimation method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To propose a pulse gap estimation device, pulse gap estimation method, and program that allow a communication frame to be set simply.SOLUTION: The invention calculates a second time (ty) from a return time point to a time point when a walking pulse (PS) appears in the next period and reaches a threshold value (TH1) on the basis of a first time (tx) from a time point when the walking pulse (PS) reaches the threshold value (TH1) to a time point when the walking pulse returns to the threshold value (TH1) via a peak. As the result, it becomes possible to set as a communication period within a walking pulse section lower than a level at which an impact is made on transmission and reception object information without requiring a walking pulse having appeared one period before the present time.

Description

  The present invention relates to a pulse gap estimation device, a pulse gap estimation method, and a program, which are suitable for communication using a human body as a communication medium.

  Conventionally, a communication system that communicates using a human body as a communication medium has been proposed by one of the present inventors (see Patent Document 1). In the communication system described in Patent Document 1, a period between pulses that periodically appear in an electric field formed on the surface of the human body as the human body walks is set as a communication period, whereby information to be transmitted / received is transmitted by the pulses. It is avoided to be destroyed.

  Specifically, the past time of the pulse peak that appears immediately before the pulse peak that appeared at the current time is stored in the memory, and the difference between the current time and the past time is added to the current time, thereby The future time of the pulse peak predicted to appear next to the time is calculated. A predetermined range in the period from the current time to the future time is set as the communication period.

JP 2004-266388 A

  However, in Patent Document 1, it is necessary to secure a walking path for detecting two walking pulse peaks that appear at the current time and the past time. However, if the walking path is lengthened, it is assumed that not only the space for arranging the walking path increases, but also that the possibility that the walking pulse peak cannot be detected increases when a plurality of people enter the walking path.

  Therefore, it has become a problem to be able to set the communication period based on the walking pulse that appears at the current time without detecting the walking pulse that appears immediately before the current time.

  The present invention has been made in view of the above points, and intends to propose a pulse gap estimation device, a pulse gap estimation method, and a program that can easily set a communication period.

  In order to solve such a problem, the present invention is a pulse gap estimation device, which is set to a first threshold value or a negative electrode side which is set to a positive electrode side of a reference potential in a signal indicating a time change of a charged electric potential generated on the human body surface. A pulse detection unit that detects a walking pulse that reaches a second threshold value from the signal, and a point from when the walking pulse detected by the pulse detection unit reaches the threshold value to a time point when it returns to the threshold value through a peak. Based on a first time, a pulse gap calculating unit that calculates a second time from the time of returning to the time when the walking pulse detected by the pulse detecting unit appears in the next cycle and reaches a threshold value; It is characterized by providing.

  The present invention is also a pulse gap estimation method, which is a first threshold value set on the positive electrode side of a reference potential or a second threshold value set on a negative electrode side in a signal indicating a time change of a charging potential generated on the human body surface. A detection step of detecting a walking pulse that reaches the threshold value from the signal, and a first time from when the walking pulse detected at the detection step reaches a threshold value to a time point when the peak pulse returns to the threshold value Based on the measurement step and the first time measured in the measurement step, the second time from the time of the return until the walk pulse detected in the detection step appears in the next cycle and reaches the threshold value. And a calculating step for calculating time.

  In addition, the present invention is a program that reaches a first threshold value set on a positive electrode side of a reference potential or a second threshold value set on a negative electrode side in a signal indicating a time change of a charged potential generated on a human body surface. Detecting a walking pulse from the signal, based on a first time from when the detected walking pulse reaches a threshold value to a time when it returns to the threshold value after the peak, the detection from the returning time point And calculating a second time until the walking pulse appears in the next cycle and reaches a threshold value.

The present inventors have found that there is a correlation between the first time and the second time regardless of gender differences, age differences, footwear differences, and the like. That is, in the present invention, based on the time (first time) when the walking pulse appearing at the current time is equal to or higher than a certain level, the time when the walking pulse appearing periodically is less than the certain level ( Second time).
Therefore, it is possible to set a walking pulse section that is less than a level that affects information to be transmitted and received as a communication period without detecting a walking pulse that appears immediately before the current time.
Thus, a pulse gap estimation device, a pulse gap estimation method, and a program that can easily set a communication period are realized.
In the present invention, it is not necessary to detect a walking pulse that appears immediately before the current time, so that the processing load is reduced as compared with the cited reference, and as a result, the responsiveness can be improved.

It is a graph which shows the example of a walk waveform. It is a graph which shows the experimental result (1) of a walk waveform. It is a graph which shows the experimental result (2) of a walk waveform. It is a figure which shows the structural example of the communication system in this embodiment. It is a figure which shows the structural example of a terminal device. It is a figure which shows the structural example of a door control apparatus. It is a figure which shows the hardware structural example of a pulse gap estimation apparatus. It is a figure which shows the functional structure of a pulse gap estimation apparatus. It is a figure which shows the relationship between the threshold value in a walk waveform, a pulse width, and a pulse gap as an example. It is a flowchart which shows a pulse gap estimation processing procedure.

(1) About a person's walk First, before describing embodiment which concerns on this invention, it demonstrates regarding a person's walk.

  When a person is walking, a charged potential generated by contact, separation and friction between the sole (or shoe sole) of the human body and the road surface is distributed like a film over the entire human body surface. When this charged potential is regarded as a time change in potential between a pair of electrodes (hereinafter referred to as a walking waveform), the walking waveform appears in a band lower than a general communication band, and has the behavior shown in FIG. Become.

  As can be seen from FIG. 1, in the walking waveform, there are a plurality of walking pulses that change sharply, and these appear periodically. Among these walking pulses, the walking pulse PS having the maximum peak is a time when one foot is completely lifted from the road surface and is standing on the other foot due to the characteristics of walking (hereinafter referred to as a free leg period). Appears on.

  For details on the appearance mechanism and the like of the walking pulse, refer to Japanese Patent Application Laid-Open No. 2008-154733 filed by one of the present inventors.

  By the way, when a threshold value is set for a walking waveform, the present inventors have a correlation between a pulse width and a pulse gap at the threshold value regardless of gender differences, age differences, footwear differences, and the like. It was found.

  Here, as a part of the experimental result regarding the correlation between the pulse width and the pulse gap, FIG. 2 shows a walking waveform when a man in his 50s walks wearing leather shoes, and when a woman in his 20s walks wearing a heel. The walking waveform is shown in FIG.

  As shown in FIGS. 2 and 3, it can be seen that the walking pulse PS appears on the positive electrode side of the reference potential in FIG. 2 and appears on the negative electrode side of the reference potential in FIG. 3. Such a reversal phenomenon of the walking pulse PS is caused by a difference in charged train between the road surface and the footwear.

  Note that the pulse width tx when the walking pulse PS appears on the positive electrode side of the reference potential is, as shown in FIG. 2, the walking pulse PS has a first threshold value TH1 set on the positive electrode side of the reference potential in the walking waveform. This is the time from the point of arrival to the point of time when the peak value is returned to the first threshold TH1.

  Further, as shown in FIG. 2, the pulse gap ty when the walking pulse PS appears on the positive electrode side of the reference potential is as follows when the walking pulse PS returns to the first threshold value TH1. This is the time until the first threshold TH1 appears in the cycle.

  Further, the pulse width tx when the walking pulse PS appears on the negative side of the reference potential is, as shown in FIG. 3, the walking pulse PS is at the second threshold TH2 set on the negative side of the reference potential in the walking waveform. This is the time from the point of arrival to the point of time when the peak value returns to the second threshold TH2.

  Further, as shown in FIG. 3, the pulse gap ty when the walking pulse PS appears on the negative electrode side of the reference potential is the following when the walking pulse PS returns to the second threshold TH2, as shown in FIG. This is the time until the second threshold TH2 appears in the cycle.

  As apparent from FIGS. 2 and 3, there is a correlation between the pulse width tx and the pulse gap ty even if there is a reversal phenomenon of the walking pulse PS, and there is a difference between men and women, age and footwear. I understand that there is. Specifically, if the coefficient for the pulse width tx is α, the relationship between the pulse width tx and the pulse gap ty is ty = α · tx.

  That is, in FIGS. 2 and 3, the value obtained by ty ÷ tx is almost the same regardless of the reversal phenomenon of the walking pulse PS and the difference in gender, age and footwear. Therefore, for example, when the average of values obtained by ty / tx is used as the coefficient α, the pulse gap ty can be estimated if the pulse width tx in the walking waveform is known.

  Although not shown here, it is known that there is a correlation even if the walking speed is different.

  In addition, the absolute values of the first threshold value TH1 and the second threshold value TH2 may be different from each other, but it is desirable that they are approximately the same.

  As described above, since the walking waveform has a correlation between the pulse width tx and the pulse gap ty, the pulse gap ty can be calculated as long as the pulse width tx is known.

(2) About Embodiment Next, an embodiment for carrying out the present invention will be described in detail with reference to the drawings.

(2-1) Configuration of Communication System As shown in FIG. 4, in this embodiment, the communication system 1 is configured with the gate device 2, the terminal device 3, the door control device 4, and the pulse gap estimation device 5 as components. .

(2-2) Configuration of Gate Device As shown in FIG. 4, the gate device 2 is provided at an entrance / exit of a company or a station, and a pair of passage walls 11A and 11B that partition the passage PG, and A door 12 that can be opened and closed on the outlet side of the passage walls 11A and 11B is provided as a main component.

(2-3) Configuration of Terminal Device The terminal device 3 is assigned to a person who is permitted to pass through the passage PG of the gate device 2, and should be possessed when the person passes through the passage PG. is there.

  As shown in FIG. 5, the casing of the terminal device 3 includes an electrode 21, a reference electrode 22, a sensor amplifier 23, a communication unit 24, and a storage unit 25 as main components.

  The electrode 21 is an electrode for transmitting and receiving information, and is provided, for example, on the inner surface of the housing. The reference electrode 22 is a ground in the terminal device 3, and is provided in parallel with the electrode 21 at a predetermined distance from the electrode 21, for example.

  The sensor amplifier 23 includes a detection element such as a FET (Field Effect Transistor) and an amplifier, detects a charged potential distributed on the surface of the human body as a signal (hereinafter referred to as a potential signal), and amplifies the potential signal. This potential signal indicates a change with time of the charging potential generated on the surface of the human body.

  When the person who is going to pass the passage PG of the gate device 2 has the terminal device 3, the communication unit 24 uses the person as a communication medium to communicate in the door control device 4 as a communication partner according to a predetermined communication method. Communicate in a frequency band higher than the frequency band of the walking waveform.

  For example, when transmitting information to the door control device 4, the communication unit 24 modulates the carrier wave according to the information and applies a modulation signal obtained as a modulation result to the electrode 21 to induce an electric field on the human body surface. In this case, the charging potential distributed on the surface of the human body due to the induction of the electric field according to the modulation signal is detected and demodulated by the door control device 4. In this way, information is transmitted to the door control device 4 using the human body as a communication medium.

  On the other hand, when acquiring information from the door control device 4, an electric field corresponding to the modulation signal is induced by the door control device 4 on the human body surface, and the charged potential distributed on the human body surface is detected by the sensor amplifier 23 due to the induction of the electric field. Is done. The communication unit 24 demodulates the potential signal output from the sensor amplifier 23 and extracts information of the door control device 4. In this way, information from the door control device 4 is acquired using the human body as a communication medium.

  The storage unit 25 stores an ID (identification) as information unique to a person who is permitted to pass through the passage PG of the gate device 2. This ID is also registered in a predetermined database. In addition, this ID is transmitted to the door control device 4 by the communication unit 24 when a person who wants to pass through the passage PG of the gate device 2 has the terminal device 3.

(2-4) Configuration of Door Control Device The door control device 4 includes an electrode 31, a reference electrode 32, a sensor amplifier 33, a communication unit 34, and an authentication unit 35 as main components as shown in FIG.

  The electrode 31 is an electrode for transmitting and receiving information, and is provided, for example, on the surface of the passage wall 11A facing the passage wall 11B, or on the surface thereof, surrounded by a dielectric. The reference electrode 22 is, for example, a ground electrode connected to the ground.

  The sensor amplifier 33 has the same configuration as that of the sensor amplifier 23 in the terminal device 3, detects a charged potential distributed on the human body surface as a potential signal, and amplifies the potential signal. As described above, this potential signal indicates a change with time of the charging potential generated on the surface of the human body.

  When the person who is going to pass through the passage PG of the gate device 2 has the terminal device 3, the communication unit 34 uses the person as a communication medium and the communication unit in the terminal device 3 that is a communication partner according to a predetermined communication method. 24 and communicate in a frequency band higher than the frequency band of the walking waveform.

  For example, when transmitting information to the terminal device 3, the communication unit 34 modulates the carrier wave according to the information and applies a modulation signal obtained as a modulation result to the electrode 31 to induce an electric field on the human body surface. In this case, the charged potential distributed on the surface of the human body due to the induction of the electric field according to the modulation signal is detected by the sensor amplifier 23 of the terminal device 3 and demodulated by the communication unit 24 of the terminal device 3. In this way, information is transmitted to the terminal device 3 using the human body as a communication medium.

  On the other hand, when acquiring information from the terminal device 3, an electric field corresponding to the modulation signal is induced on the human body surface by the communication unit 24 of the terminal device 3, and the charged potential distributed on the human body surface due to the induction of the electric field is detected by the sensor amplifier 33. Is detected. The communication unit 34 demodulates the potential signal output from the sensor amplifier 33 and extracts information of the terminal device 3. In this way, information from the terminal device 3 is acquired using the human body as a communication medium.

  When the ID of the terminal device 3 is acquired by the communication unit 34 and the ID is given from the communication unit 34, the authentication unit 35 collates with a plurality of IDs registered in a predetermined database in a predetermined order.

  Here, when a collation result is obtained in which the ID of the terminal device 3 does not match all of the plurality of IDs registered in the database, the authentication unit 35 keeps the door 12 in the closed state as it is, It is notified by voice or the like that it cannot pass through the passage PG.

  On the other hand, when the collation result in which the ID of the terminal device 3 matches one of the plurality of IDs registered in the database is obtained, the authentication unit 35 opens the door 12 in the closed state.

(2-5) Configuration of Pulse Gap Estimation Device As shown in FIG. 7, the pulse gap estimation device 5 connects various hardware to a CPU (Central Processing Unit) 40 that controls the pulse gap estimation device 5. It is constituted by doing.

  For example, a ROM (Read Only Memory) 41, a RAM (Random Access Memory) 42 serving as a work memory of the CPU 40, a monitor 43, an input unit 44 such as a mouse, and a storage unit 45 such as an HDD (Hard disk drive) are connected via a bus 46. Connected. The storage unit 45 stores a program for estimating a pulse gap (hereinafter referred to as a pulse gap estimation program).

  When the pulse gap estimation program is expanded in the RAM 42, the CPU 40 functions as an input unit 51, a pulse detection unit 52, a pulse gap calculation unit 53, and a communication condition command unit 54 as shown in FIG.

  The input unit 51 is a unit that inputs a potential signal (a signal indicating a temporal change in the charged potential generated on the human body surface) detected by the sensor amplifier 33 of the door control device 4. This potential signal includes a walking waveform.

  The input unit 51 extracts a band component lower than the communication band in the communication unit 24 from the potential signal as necessary.

  This extraction method includes one or both of a method of sampling at a period slower than the sampling period of the communication unit 34 in the door control device 4 and a method of filtering other than the band lower than the communication band in the communication unit 34. Adopted.

  As shown in FIG. 9, the pulse detection unit 52 sets the first threshold value TH1 set on the positive electrode side of the reference potential in the potential signal output from the input unit 51 or the second threshold value TH2 set on the negative electrode side. The arriving walking pulse PS is detected from the potential signal.

  In addition, the case where the walking pulse PS that appears in the swing phase is on the positive electrode side of the reference potential is shown. The reference potential in the potential signal is the potential of the reference electrode 32 in the door control device 4.

  For example, when the pulse detection unit 52 detects a walking pulse PS that reaches the first threshold value TH1, the pulse gap calculation unit 53 performs a peak from the point in time when the walking pulse PS reaches the first threshold value TH1. The first time (pulse width tx) until the time when the threshold value TH1 is returned to 1 is measured.

  Further, when measuring the pulse width tx, the pulse gap calculation unit 43 multiplies the pulse width tx by the coefficient α, and the walking pulse PS detected by the pulse detection unit 42 appears in the next cycle, and the first threshold value A second time (pulse gap ty) until reaching TH1 is calculated.

  The coefficient α is set to a value input via the input unit 44 (FIG. 7), and the set value can be appropriately changed via the input unit 44.

  The communication condition command unit 54 notifies the communication unit 34 of the door control device 4 of the pulse width tx and the pulse gap ty obtained in the pulse gap calculation unit 53 and communicates within the pulse gap ty as a communication period. Commands the communication unit 34 of the door control device 4.

  In this case, the communication unit 34 of the door control device 4 starts communication based on the pulse width tx and the pulse gap ty notified from the communication condition command unit 54 when starting communication with the communication unit 24 of the terminal device 3. Communication conditions such as time and frame interval are set, and communication is performed according to the communication conditions.

(2-6) Processing Procedure of Pulse Gap Estimation Device By the way, the pulse gap estimation device 5 described above goes through a routine shown in FIG.

  That is, the pulse gap estimation device 5 starts a routine, for example, when power is turned on, and proceeds to the first stage SP1A of the detection step SP1.

  In the first step SP1A of the detection step SP1, the pulse gap estimation device 5 starts to input a potential signal detected by the sensor amplifier 33 of the door control device 4, and proceeds to the second step SP1B of the detection step SP1.

  In the second stage SP1B of the detection step SP1, the pulse gap estimation device 5 determines whether or not the walking pulse PS in the potential signal has reached the first threshold value TH1, and if a negative result is obtained, the detection step Proceed to the third stage SP1C of SP1.

  In the third stage SP1C of the detection step SP1, the pulse gap estimation device 5 determines whether or not the walking pulse PS in the potential signal has reached the second threshold value TH2, and if a negative result is obtained, the detection step Return to the second stage SP1B of SP1.

  As described above, the pulse gap estimation device 5 sequentially performs the walking pulse PS through the second stage SP1B and the third stage SP1C of the detection step SP1 until a positive result is obtained in the second stage SP1B or the third stage SP1C of the detection step SP1. To monitor.

  On the other hand, if a positive result is obtained in the second stage SP1B or the third stage SP1C of the detection step SP1, the pulse gap estimation device 5 proceeds to the measurement step SP2 and the pulse width tx of the walking pulse PS detected in the detection step. Start measuring. Then, when the measurement of the pulse width tx is completed, the pulse gap estimation device 5 proceeds to the next calculation step SP3.

  In the calculation step SP3, the pulse gap estimation device 5 calculates the pulse gap ty by multiplying the pulse width tx measured in the measurement step SP2 by the coefficient α, and proceeds to the next communication condition command step SP4.

  In the communication condition command step SP4, the pulse gap estimation device 5 instructs the communication unit 34 of the door control device 4 to communicate within the pulse gap ty calculated in the calculation step SP3 as the communication period, and then detects the detection step SP1. Return to the second stage SP2A.

(2-7) Effect etc. As described above, in this embodiment, the walking pulse PS that appears periodically is based on the time (pulse width tx) in which the walking pulse PS that appears at the current time is equal to or higher than a certain level. A time (pulse gap ty) that is less than a certain level is captured.

  Therefore, it is possible to set a walking pulse section that is less than a level that affects information to be transmitted and received as a communication period without detecting a walking pulse PS that appears immediately before the current time.

  In addition, in this embodiment, since the detection of the walk pulse which appeared immediately before the present time becomes unnecessary, the processing load is reduced compared with the case where the pulse gap ty is estimated also using the walk pulse. As a result, responsiveness can be improved.

(3) About other embodiment In the said embodiment, the pulse gap estimation apparatus 5 was connected to the door control apparatus 4 used as the authentication side. However, the pulse gap estimation device 5 may be connected to the terminal device 3 on the authenticated side.

  Note that the pulse gap estimation device 5 connected to the terminal device 3 may be incorporated as a part of a component (pulse gap estimation unit) in a card terminal or a mobile phone. Even if it does in this way, the effect similar to the above-mentioned embodiment can be acquired.

In the above embodiment, the pulse width tx is measured from the time when the pulse gap estimation device 5 detects the walking pulse PS that reaches the first threshold value TH1 or the second threshold value TH2.
In addition to the measurement of the pulse width tx, the pulse gap estimation device 5 notifies an external device such as the door control device 4 that the walking pulse PS reaching the first threshold value TH1 or the second threshold value TH2 is detected. You may make it do.
The fact that the walking pulse PS reaching the first threshold value TH1 or the second threshold value TH2 has been detected means that a person has started to pass through the passage PG of the gate device 2 or that the person has approached the entrance of the passage PG. Means that
Accordingly, when the external device is notified that the walking pulse PS has been detected when the walking pulse PS reaching the first threshold value TH1 or the second threshold value TH2 is detected, the external device is gated. It can be recognized that a person has started to pass through the passage PG of the apparatus 2 or that a person has approached the entrance of the passage PG.

  The present invention can be used, for example, in the transportation industry, agriculture, mining, forestry, fishery, construction industry, manufacturing industry, electrical industry or information communication industry, and of course, it can be widely used in all other industries. In addition to the content shown in the above-described embodiment or other embodiments, the present invention can add a technique that is well-known to the industry to be used, and can omit or change the content. .

  DESCRIPTION OF SYMBOLS 1 ... Communication system, 2 ... Gate apparatus, 3 ... Terminal apparatus, 4 ... Door control apparatus, 5 ... Pulse gap estimation apparatus, 11A, 11B ... Passage wall, 12 ... Door, 21, 31, ... ... Electrode, 22, 32 ... Reference electrode, 23, 33 ... Sensor amplifier, 24, 34 ... Communication part, 25, 45 ... Storage part, 35 ... Authentication part, 40 ... CPU, 41 ... ROM 42 …… RAM, 43 …… Monitor, 44 …… Input unit, 51 …… Input unit, 52 …… Pulse detection unit, 53 …… Pulse gap calculation unit, 54 …… Communication condition command unit, SP1 …… Detection Step, SP2 ... Measurement step, SP3 ... Calculation step, SP4 ... Communication condition command step.

Claims (4)

A pulse for detecting a walking pulse that reaches a first threshold value set on the positive electrode side or a second threshold value set on the negative electrode side of a reference potential in a signal indicating a temporal change in the charged potential generated on the human body surface from the signal. A detection unit;
Based on the first time from the time when the walking pulse detected by the pulse detection unit reaches the threshold value to the time when the walking pulse returns to the threshold value after the peak, the pulse detection unit detected from the returned time point. A pulse gap estimation device comprising: a pulse gap calculation unit that calculates a second time until a walking pulse appears in a next cycle and reaches a threshold value. The pulse gap calculator
The pulse gap estimation apparatus according to claim 1, wherein the second time is calculated by multiplying the first time by a coefficient. Detection that detects a walking pulse that reaches a first threshold value set on the positive electrode side or a second threshold value set on the negative electrode side of a reference potential in a signal indicating a temporal change in the charged potential generated on the human body surface from the signal. Steps,
A measurement step of measuring a first time from the time when the walking pulse detected in the detection step reaches a threshold value to the time when the walking pulse returns to the threshold value through a peak;
Based on the first time measured in the measurement step, the second time from the time of the return to the time when the walking pulse detected in the detection step appears in the next cycle and reaches the threshold is calculated. A pulse gap estimation method comprising: a calculation step. Detecting from the signal a walking pulse that reaches a first threshold value set on the positive electrode side or a second threshold value set on the negative electrode side of a reference potential in a signal indicating a temporal change in the charged potential generated on the surface of the human body. ,
Based on the first time from when the detected walking pulse reaches the threshold value to the time when the detected walking pulse returns to the threshold value after the peak, the detected walking pulse appears in the next cycle from the returned time point. A program for calculating a second time until a threshold is reached.

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