JP5430519B2 - Relative direction estimation method, search side terminal, and searched side terminal - Google Patents

Description

  The present invention relates to a relative direction estimation method, a search-side terminal, and a searched-side terminal, and in particular, estimates a relative direction between terminals using a general mobile terminal that does not require special hardware or the like for each terminal. The present invention relates to a relative direction estimation method, a search-side terminal, and a searched-side terminal.

  The estimation of the relative direction between terminals is useful in various applications, and there are techniques disclosed in Patent Documents 1 to 3 shown below as conventional techniques for realizing this.

  Patent Document 1 (search system) discloses a technique in which both terminals acquire position information using GPS (Global Positioning System) and share the acquired position information to estimate a relative direction. ing.

  In Patent Document 2 (pedestrian guidance support system), an infrastructure facility of an ultrasonic transmitter / receiver whose position information is known is installed in an actual field, and a terminal capable of transmitting / receiving ultrasonic waves is used. First, the distance is measured by transmitting and receiving ultrasonic waves between the infrastructure equipment and the terminal. Similarly, the distance between a plurality of infrastructure facilities and terminals is measured. Next, the position information of the terminal is obtained with high accuracy using the distance to a plurality of infrastructure facilities in the manner of three-point surveying. Finally, the relative position is estimated by sharing the acquired position information between terminals.

  In Patent Document 3 (arrival direction estimation device, arrival direction estimation method, and arrival direction estimation program), a terminal having a directional antenna is used to determine the arrival angle of a radio wave when transmitting / receiving radio waves to / from a counterpart terminal, and the relative direction is determined. presume.

JP 2007-208414 JP JP 2010-101711 A JP 2009-243947

  Although it is possible to estimate the relative direction between terminals by the above prior art, each has the following problems. In the technique disclosed in Patent Document 1, since the position information used in the GPS includes an error of about 5 m, the accuracy of the relative direction estimated from the position information is insufficient.

  Further, the technique disclosed in Patent Document 2 requires infrastructure installation in an actual field, and requires a large infrastructure installation cost. Moreover, since it is necessary to add special terminals or special hardware to the terminals, generally available terminals cannot be used as they are. Furthermore, in the technique disclosed in Patent Document 3, similar to the technique disclosed in Patent Document 2, it is necessary to add special hardware to the terminal.

  The object of the present invention is to solve the above-mentioned problems of the prior art, without using infrastructure or special hardware, and using only a general terminal such as a mobile terminal, and the relative direction between the terminals with high accuracy. A relative direction estimation method that can be estimated, and a search-side terminal and a searched-side terminal are provided.

  In order to achieve the above object, the present invention provides a relative direction estimation method for estimating a relative direction of a searched side terminal from a searching side terminal, and sets the information to start the estimation and the sound wave used for the estimation. A notification step of notifying the search side terminal of the first time change information from the search side terminal using wireless communication, and a recording start step in which the search side terminal starts recording after the notification step Then, after the notification stage, an exercise stage in which a predetermined movement for changing the orientation of the terminal is applied to the search side terminal, and the search side terminal sets the first time change simultaneously with the exercise stage A sound wave transmission step for transmitting sound waves, a direction acquisition step for acquiring a time change in the direction of the search side terminal in the exercise step, and the end of the exercise step for wireless communication from the search side terminal to the search target side terminal. Using the notification A recording end stage in which the terminal ends the started recording, and after the recording end stage, the searched terminal uses the notified first time change information to make the first time change from the recording. And extracting the second time change information, which is the time change of the point, to the search side terminal, the first time change information, and the second time. A first feature is that the search-side terminal estimates the relative direction based on change information and a time change of the direction acquired in the direction acquisition step.

  Further, in the present invention, the first time change is a time change in which the sound wave to be transmitted is a plurality of pulsed sound waves provided with a first time interval sequence, and the second time change is greater than the recording. A portion where a volume increase is seen in a pulse shape at an interval having a strong correlation with the first time interval row is extracted, and a second time interval row which is a sequence of a plurality of pulse-like volume increase time intervals at the location. The second feature is that the time changes as follows.

  In the present invention, the first time change is a time change in which the sound wave to be transmitted is a predetermined frequency band and a plurality of pulsed sound waves provided with a first time interval sequence, and the second time change is From the recording, a portion where a volume increase is seen in a pulse shape at an interval having a strong correlation with the first time interval sequence, and a portion substantially matching the predetermined frequency band is extracted, and a plurality of pulse-like volume increases in the portion A third feature is that the second time interval sequence is a time change as a second time interval sequence.

  Further, the present invention uses the time corresponding to the place where the sign is inverted in the time interval sequence that is the difference obtained by subtracting the second time interval sequence from the first time interval sequence. The direction corresponding to the time is obtained from the time change of the direction acquired in the direction acquisition step. If the sign inversion is negative, the direction is estimated as the relative direction, and the sign inversion is positive. Then, the fourth feature is that the opposite direction is estimated as the relative direction.

  The fifth feature of the present invention is that the first time interval sequence is determined using a random number.

  The sixth feature of the present invention is that the predetermined motion is a substantially semicircular and substantially horizontal swing motion with a substantially constant radius centered on a stationary position of the search side terminal. .

  Further, the present invention is characterized in that the direction acquisition step acquires a time change of the direction of the search side terminal using a geomagnetic sensor.

  Furthermore, the present invention is characterized in that the relative direction estimation method is used for waiting for a user of the search side terminal and a user of the search side terminal.

  In order to achieve the above object, the present invention provides a search-side terminal that estimates a relative direction of a search-side terminal, a sound wave setting / transmission unit that transmits a sound wave set with a time change, and the search-side terminal A direction acquisition unit that acquires a direction, a wireless communication unit that wirelessly communicates with the searched-side terminal, and a relative direction estimation unit that estimates a relative direction in which the searched-side terminal exists, and starts the estimation And the first time change information used for the estimation are notified to the searched terminal via the wireless communication unit, and then the searched terminal starts receiving a sound wave, and Simultaneously with a predetermined motion applied to change the direction, the sound wave setting / transmission unit transmits a sound wave in which the first time change is set, and the direction acquisition unit acquires the direction of the search side terminal during the transmission. , A second time change at a location identified as a location having a stronger correlation with the first time change than the sound wave received by the searchee side terminal based on the information on the first time change. The time change information is returned via the wireless communication unit, and the relative direction estimation unit obtains the first time change information, the second time change information, and the search side acquired during the transmission. A ninth feature is that the relative direction is estimated based on the orientation of the terminal.

  Furthermore, in order to achieve the above object, the present invention provides a searched-side terminal whose relative direction is estimated by a search-side terminal, which receives a sound wave and identifies a time change of the sound wave; A wireless communication unit that wirelessly communicates with the search side terminal, and information on the start of the estimation and information on a first time change set in a sound wave used for the estimation via the wireless communication unit After receiving notification from the terminal, the sound wave reception / identification unit starts receiving sound waves, and the search side terminal sets the first time change simultaneously with a predetermined motion applied to change the direction of the search side terminal. The sound wave is transmitted and the direction of the search-side terminal during the transmission is acquired, and the sound wave reception / identification unit detects the received sound wave based on the first time change information in the notification. Correlation with change A strong portion is identified to obtain a second time change that is a time change of the portion, information on the second time change is returned to the search side terminal via the wireless communication unit, and the search side terminal is returned to the search side terminal. A tenth feature is that the relative direction is estimated based on the information on the first time change, the information on the second time change, and the direction of the search terminal acquired during the transmission.

  According to the first feature, a terminal using a principle corresponding to the Doppler effect accompanying sound source movement by using a wireless function, a sound wave transmission / reception function, and a direction acquisition function that can be easily provided in a general portable terminal. The relative direction between them can be estimated.

  According to the second feature, the relative direction between the terminals can be estimated using a principle corresponding to the Doppler effect accompanying the movement of the sound source with respect to the change in the pulse interval of the transmitted / received sound wave.

  According to the third feature, the principle corresponding to the Doppler effect accompanying the movement of the sound source with respect to the change in the pulse interval of the transmitted / received sound wave after extracting the sound wave corresponding to the transmitted sound wave easily from the recording by the frequency information. It is possible to estimate the relative direction between terminals.

  According to the fourth feature, the direction corresponding to the inversion portion or the opposite direction can be determined as the relative direction between the terminals.

  Further, according to the fifth feature, by determining a time interval with a random number and notifying the searched terminal of the information, the searched terminal can easily extract a portion corresponding to the transmitted sound wave from the recording. be able to.

  According to the sixth feature, the relative direction between the terminals can be estimated using the principle corresponding to the Doppler effect in the sound source movement by swing.

  According to the ninth feature, the terminal using the principle corresponding to the Doppler effect accompanying the sound source movement by utilizing the wireless function, the sound wave transmission / reception function, and the direction acquisition function that can be easily provided in a general portable terminal. It is possible to provide a search side terminal in a method capable of estimating a relative direction between the terminals.

  According to the tenth feature, a terminal using a principle corresponding to the Doppler effect accompanying sound source movement by utilizing a wireless function, a sound wave transmission / reception function, and a direction acquisition function that can be easily provided in a general portable terminal. It is possible to provide a searched terminal in a method capable of estimating a relative direction between the terminals.

It is a figure which shows the outline | summary of the relative direction estimation between the terminals in this invention. It is a figure which shows the numerical example of the terminal direction at the time of each sound wave generation for estimating a relative direction in the example of FIG. 1, and the transmission interval and reception interval in the area between each sound wave generation time. It is a block diagram which shows an example of a structure of the general portable terminal which can implement | achieve the search side terminal and searchee side terminal in this invention. It is a block diagram including the response relationship between each terminal at the time of relative direction estimation of the searching side terminal and the searched side terminal of the present invention. It is a figure which shows the example which avoids the competition between the other multiple pairs which are performing the connection of the several sound wave in the received sound wave using the information of transmission interval, and the same direction estimation. It is a figure which shows the procedure sequence between the search side terminal for performing a relative direction estimation, and a to-be-searched side terminal. It is a flowchart which shows the process in the search side terminal in the procedure sequence of FIG. It is a flowchart which shows the process in the to-be-searched terminal in the procedure sequence of FIG.

  Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram for explaining an outline of relative direction estimation between terminals according to the present invention. In FIG. 1, the direction from the terminal on the searching side (a) to the terminal on the searching side (b) according to the present invention in a planar place area of, for example, several tens of meters where sound waves can reach, such as an outdoor meeting square. Is estimated. First, the search side (a) and the searched side (b) are capable of wireless communication, and mutually recognize that the relative direction estimation is now performed from (a) to (b) by the wireless. Suppose you are in a state.

  Next, as shown in (a1), for example, the owner of the search side terminal swings the search side terminal substantially on the horizontal plane by holding the search side terminal in his hand and rotating it around the elbow. At this time, with the passage of time of rotation as shown in the drawing, a plurality of pulsed sound waves S (1) to S (5) such as 5 times are transmitted from the search side terminal. Then, the search side terminal records each time when each sound wave is generated and the direction of the search side terminal at each time.

  In the terminal of the searched side (b), at the start of the direction estimation, information for identifying the transmitted sound wave such as the interval of the sound wave transmitted by the searching side (a) in (a1) Recording is started as appropriate, and a notification to the effect that the sound wave transmission has been completed is received from the search side (a) and the recording is ended. The search target side (b) uses the identification information of the transmitted sound wave to identify the corresponding received sound from the recording, finds the reception interval from the reception time corresponding to each sound wave S (1) to S (5), and searches The interval is wirelessly transmitted to the side (a).

  Further, the search side (b) by the information of the identification, the search side that is a pair partner that performs the relative direction estimation and the sound generated by the passerby (c) that performs the direction estimation as another pair, etc. It is also possible to distinguish from the transmitted sound of (a).

  The search side (a) receives the reception interval, compares it with its own transmission interval, and estimates the relative direction. FIG. 2 shows an example of the terminal orientation, transmission interval, and reception interval at the time of each sound wave transmission used for the estimation. In FIG. 2, the transmission interval (100 ms) is longer than the reception interval (99 ms) in the interval between the transmission of the sound waves S (1) and S (2), and the reverse relationship is established in the subsequent intervals. As shown in FIG. 1, the mechanism of this result is that the reception interval is greater than the transmission interval based on the same principle as the Doppler effect in relation to the relative direction between the search side (a) and the searched side (b) and the swing area of the terminal. Narrow section (a2) [Sound wave S (1), S (2) transmission section] and section where reception interval is wider than transmission interval (a3) [Sound wave S (3), S (4), S (5) transmission section] This is because a distinction arises. The search side (a) extracts the difference due to such a principle between the transmission interval and the reception interval, and the sound waves S (2) and S (3), which are the directions in which the magnitude relationship between the reception interval and the transmission interval is reversed. ) Is transmitted as a relative direction in which the searched side (b) exists.

  As a feature of the present invention, there is a point that such a search-side terminal and a searched-side terminal that enable such relative direction estimation can be realized by a mobile terminal 100 having a general configuration as shown in FIG. A typical portable terminal 100 includes, for example, a control unit 101, a storage unit 102, an input unit 103, a display unit 104, a communication unit 105, a voice input / output unit 106 including a microphone 107 and a speaker 108, a timing unit 109, and an additional function unit 110. And a bus 200.

  The control unit 101 controls each unit and each unit, and the storage unit 102 stores temporary or fixed information necessary for the operation of the control unit or the like. The input unit 103 includes a keypad and receives user input. The display unit 104 includes a display and displays various information for the user. The communication unit 105 includes an antenna and the like and performs communication in various communication forms. The voice input / output unit 106 includes a microphone 107 and a speaker 108, and is used during a call and during playback and recording of voice data. The clock unit 109 plays the role of a clock. The additional function unit 110 provides functions according to various other user applications. The bus 200 is responsible for data transfer between the units.

  As will be described below, the search-side terminal and the searched-side terminal of the present invention can be realized as a partial function or an additional function using such a general mobile terminal 100. Further, as will be apparent from the following description, the terminal functions of the search side terminal and the searched side terminal of the present invention are simultaneously provided in one terminal, and the terminal uses different functions for each position of the search side / searched side. Can also be realized by a general portable terminal 100.

  FIG. 4 shows a functional block diagram of the configuration of each part of the search side terminal and the searched side terminal including the relationship at the time of relative direction estimation in the present invention. The search side terminal 10 includes a relative direction estimation unit 11, a direction acquisition unit 12, an input unit 13, a wireless communication unit 14, a sound wave setting / transmission unit 15, and a bus 16 that performs data transfer between these units. The searched terminal 20 includes a wireless communication unit 21, a sound wave reception / identification unit 22, an input unit 23, and a bus 24 that performs data transfer between these units.

  The relative direction estimation unit 11 estimates the direction of the searched-side terminal 20 using information obtained from each unit of the searching-side terminal 10 and information obtained from the searched-side terminal 20 as shown in FIG. The relative direction estimation unit 11 can be included in the additional function unit 110, for example. The direction acquisition unit 12 acquires the direction of the search-side terminal 10 together with the time, and can be included in the additional function unit 110 and the time measuring unit 109, for example. In one embodiment, the direction acquisition unit 12 acquires a direction using a geomagnetic sensor. The input unit 13 (search side terminal 10 side) includes buttons and the like, and the search side terminal indicates that the user activates the search side terminal 10 to start relative direction estimation, completes each stage of direction estimation, and the like by pressing a button. 10 is notified. As the input unit 13, the input unit 103 of the mobile terminal 100 can be used.

  The wireless communication unit 14 of the search-side terminal 10 and the wireless communication unit 21 of the searched-side terminal 20 wirelessly communicate with each other via space, a network, or the like using Bluetooth (registered trademark), wireless LAN, 3G, Zigbee (registered trademark), or the like. Then, data used for relative direction estimation such as sound wave transmission intervals and reception intervals and inter-terminal synchronization signals at each stage in the relative direction estimation flow are transmitted and received between the terminals. The wireless communication unit 14 and the wireless communication unit 21 can use the communication unit 105 of the mobile terminal 100.

  The sound wave setting / transmission unit 15 sets what kind of sound wave is transmitted, for example, sets a transmission interval and a frequency band of the pulsed sound wave, and transmits the sound wave through a speaker or the like. For the sound wave setting / transmission unit 15, a speaker 108, an additional function unit 110, a time measuring unit 109, and the like can be used. For example, a chirp signal having a signal length of 50 ms and a frequency band of 2 to 6 kHz that can be transmitted by a speaker 108 included in a general mobile terminal 100 is used as an actually transmitted sound wave. Can be reduced. Ultrasound can also be used if the speaker / microphone is compatible.

  The sound wave reception / identification unit 22 receives and records sound waves with a microphone or the like and is transmitted from the sound wave setting / transmission unit 15 from the recording using information such as a transmission interval received in advance via the wireless communication unit 21. Identify the sound wave. For the sound wave reception / identification unit 22, a microphone 107, an additional function unit 110, a time measuring unit 109, and the like can be used.

  The input unit 23 (searched side terminal 20 side) accepts a user input of the searched side terminal 20 including a response to synchronization confirmation from the search side terminal 10 at each stage of relative direction estimation. The searched terminal 20 may automatically respond without using 23. The input unit 103 of the mobile terminal 100 can also be used for the input unit 23.

  Next, details of performing relative direction estimation by each of the constituent blocks available in the general mobile terminal 100 as described above will be described in the order of determination of a transmission interval, identification of a received sound wave, and relative direction estimation.

  The sound wave / setting transmission unit 15 first determines the transmission interval of the sound wave pulse train to be transmitted. For example, (n−1) transmission intervals I_t (i) (i = 1, 2,..., When transmitting n pulsed sound waves S (i) (i = 1, 2,..., N) n-1) is an irregular interval, and the non-search side terminal 20 is notified in advance of the transmission interval via wireless communication, so that multiple pairs of multiple sound waves and similar pairs of direction estimations are performed. It is possible to avoid conflicts between them. The transmission interval is determined using the following equation (1).

  I_t (i) = rand (m) × 50ms (1)

  Here, rand (m) is a variable that randomly generates a natural number of m or less.

  FIG. 5 shows an example of using a transmission interval information to avoid a competition among a plurality of other pairs that perform a combination of a plurality of sound waves and a similar direction estimation. FIG. 5A shows an example of connecting multiple sound waves. For example, m = 3 in equation (1), and the search-side terminal 10 uses three sound waves S (1), S (2), and S (3) as transmission intervals I_t (1) = 100 ms, I_t (2) = An example in which the non-search side terminal 20 receives two sound waves R (1) and R (2) at a reception interval I_r (1) = 100 ms and cannot receive the remaining one sound wave is transmitted in 150 ms. FIG. 5 (A). In this case, R (1) = S (1) and R (2) = S (2) are linked by comparing the transmission interval acquired in advance by wireless communication with the reception interval received by the sound wave reception / identification unit 22. Is possible.

  Next, FIG. 5B shows an example of conflict avoidance between a plurality of pairs. When there are a plurality of pairs of the search-side terminal 10 and the non-search-side terminal 20 and the relative direction estimation is performed separately, when the sound waves are transmitted at the same time, there is a possibility that competition occurs and the sound waves more than necessary are received. In FIG. 5A, the search side terminal transmits three sound waves S (1), S (2), S (3) at transmission intervals I_t (1) = 100 ms, I_t (2) = 150 ms, and no search The side terminal receives four sound waves R (1), R (2), R (3), R (4) at reception intervals I_r (1) = 100ms, I_r (2) = 100ms, I_r (3) = 50ms An example received is shown. In this case as well, R (1) = S (1), R (2) = S (2), R (4) = S (3) can be linked by comparing the transmission interval and reception interval acquired in advance. Is possible. As another method for avoiding competition between a plurality of pairs, there is a method using a different frequency band for each pair.

  In the above example of FIG. 5, the case where a sound wave pulse cannot be received or received excessively has been described. However, the same technique can be applied to distinguish from other received noise or reception error in general. In the description of FIG. 5, it is assumed that a sound wave pulse train as illustrated from the received sound wave is obtained, but this is performed by the sound wave receiving / identifying unit 22 as follows.

  The sound wave reception / identification unit 22 receives and records sound waves, and calculates the reception time from the recorded data. Subsequently, a sound wave reception interval is calculated from the calculated reception time, and the calculated reception interval is returned to the search-side terminal 10 via wireless communication. Here, the reception time is calculated by using the transmission sound wave waveform sample shared between both terminals in advance together with the transmission interval information, that is, the frequency band information of the transmission sound wave, and the correlation value between the sample and the recorded data on the time axis. Calculate The correlation value is calculated while shifting the time axis, and the point that becomes the peak value is calculated as the reception time. After calculating one reception time, the calculation processing load can be reduced by using the information of the transmission interval acquired in advance to give a guide for the reception time of the remaining sound waves. (Hereinafter referred to as Embodiment A)

  In addition to the above-described embodiment A in which the correlation is first calculated for the first pulse and the reception time of the first pulse is obtained, information on the entire transmission pulse train (pulse interval and frequency of each pulse) is calculated. A portion where volume increase occurs in a pulse shape in the recording data may be obtained by calculating correlation while sequentially shifting in the time axis shape using the band information) (Embodiment B). In this case, the transmission interval and the reception interval do not completely coincide with each other based on the principle corresponding to the Doppler effect. Therefore, when determining the correlation, a predetermined error is allowed for the pulse interval.

  In addition, the embodiment B has an effect that it can detect the entire pulse train more accurately than the embodiment in which the first pulse is first detected, in particular, in a noisy situation, instead of having a larger calculation amount than the embodiment A. . Even in the case of Embodiment A in which the first pulse is detected, if the transmission interval cannot be reproduced even if error detection as described in FIG. 5 is performed thereafter, the second and subsequent points of the peak value are sequentially received. You may look for the location which can reproduce a transmission interval as time.

  As described above, the sound wave reception / identification unit 22 uses the information on the transmission interval and the information on the frequency band of each pulse for identification from noise or the like as necessary, based on the recording data, the transmission interval (and (Frequency band) and pulse-like data having a strong correlation in the time axis direction are extracted as shown in the example of the reception interval in FIGS. 5A and 5B (same as in Embodiments A and B), and the extracted data is When an error is included as shown in FIGS. 5A and 5B, a pulse that constitutes a reception interval only using pulses that do not include an error as described with reference to FIG. 5 using the correlation with the transmission interval and the frequency band. Identify as. In other words, the sound wave reception / identification unit 22 first detects the pulse-like peak location from the recorded data, and further obtains the reception interval corresponding to the transmission sound wave from each peak, and then correlates with the transmission interval. Use.

  In the above description, the sound wave to be transmitted is described as a pulse train having an interval. Although the embodiment of the pulse train is a preferred embodiment as a transmission sound wave, the present invention is not limited to the embodiment. If the information equivalent to the transmission interval and the reception interval, that is, the state identification of the transmitted sound wave at each time and the reception sound wave corresponding to each state can be identified, more generally, for example, a sound wave having a continuous time change is used. It doesn't matter.

  For example, the state of the transmitted sound wave is recorded at each time during the sound wave transmission from the search side terminal 10 using a sound wave having a time change such that the frequency, the volume, etc. change continuously / intermittently / stepwise. In addition, by using the information of the state, identification processing may be similarly performed on the received sound wave to extract information corresponding to the reception interval.

  In the present invention, for ease of explanation, the following explanation will mainly explain terms such as a transmission interval and a reception interval assuming a pulse train acoustic wave, but more general transmission acoustic waves as described above. It is obvious that the present invention can also be applied to a sound wave provided with a time change.

  Next, details of the relative direction estimation unit 11 estimating the relative direction in which the searched-side terminal 20 exists when viewed from the search-side terminal 10 will be described. As schematically illustrated in FIG. 1, while transmitting the sound wave set by the sound wave setting / transmission unit 15, the search-side terminal 10 is at the same time substantially horizontally with the user holding the terminal. A swing operation is performed around a stationary position where the user is located in a circle having a substantially constant radius corresponding to the length of the user's arm. Then, the direction of the search-side terminal 10 at the time of transmitting each pulse sound wave during the swing operation is acquired by the direction acquisition unit 12 together with the time.

  Note that it is essential that the swing operation has a predetermined radius and a positional movement with a change in the orientation of the terminal because the present invention uses the principle corresponding to the Doppler effect due to the movement of the wave source. For example, if the terminal is simply rotated at a fixed position, the relative direction estimation becomes difficult because there is (almost) no position movement.

  After the sound wave transmission associated with the swing operation is completed, a reception interval is calculated by the above-described processing of the sound wave reception / identification unit 22 in the searched terminal 20 and is passed to the relative direction estimation unit 11 via wireless communication. The relative direction estimation unit 11 uses a mechanism corresponding to the Doppler principle by using the reception interval, the transmission interval of the sound wave set in advance and transmitted from the sound wave reception / identification unit 22, and the direction acquired at each pulse transmission time. Thus, the relative direction of the searched terminal 20 is estimated. That is, the reception interval of the sound wave transmitted to the section where the searching side is approaching the non-search side during the swing is narrower than the transmission interval, and the reception interval of the sound wave transmitted to the section moving away is wider than the transmission interval. From this, the sound wave used as the boundary of both areas is specified, and the terminal direction at the time of transmitting the sound wave can be estimated as the relative direction.

  Specifically, it is estimated as follows. The transmission interval when transmitting n sound waves S (i) (i = 1, 2,..., n) is I_t (i) (i = 1, 2,..., n−1), and the reception interval is I_r ( i) (i = 1, 2,..., n−1), the terminal direction is D (i) (i = 1, 2,..., n), and the relative direction RD is obtained by the following equation (2).

  RD = D (i + 1) (i satisfies I_t (i)> I_r (i) and I_t (i + 1) ≦ I_r (i + 1)) (2)

  Here, when the searched-side terminal 20 is located behind the direction in which the searched-side terminal 10 is swung, the terminal orientation satisfying the expression (2) cannot be obtained. In that case, the following equation (3) is used to identify the section where the reception interval is wider than the transmission interval and the sound wave that is the boundary of the section where the reception interval is wider than the transmission interval. Estimated relative direction RD.

  RD = D (i + 1) (i satisfies I_t (i) <I_r (i) and I_t (i + 1) ≧ I_r (i + 1)) (3)

  The relative direction estimation is shown by taking the data of FIG. 2 as an example. Transmits five sound waves S (1) to S (5), and each sound wave S (i) transmission direction D (i), transmission interval I_t between sound waves S (i) and S (i + 1) (i) Assume that the reception intervals I_r (i) between the received sound waves R (i) and R (i + 1) are as shown in the figure. In this case, the relative direction RD = D (2) = 45 ° is estimated from the equation (2).

  In the above example, the estimated direction may be a direction between D (2) = 45 ° and the next D (3) = 90 °, but in general, the search is already performed by taking a fine transmission interval. There is no problem even if it is determined as D (2) (or D (3)) that the angle data exists on the side terminal 10 side and the result can be immediately displayed to the user.

  In the above formulas, the formulas (2) and (3), the case is divided on the assumption that the swing motion is by hand and is a semicircle of approximately 180 °. On the contrary, if the formula (2) or (3) is applied, the circle of the swing motion may be 180 ° because the estimated direction is determined. As an application example of the equations (2) and (3), the case where data as shown in FIG. 2 is obtained with the arrangement as shown in FIG. 1 is shown. In this data, as shown in FIG. 1, the example is swinging clockwise, but the expressions (2) and (3) can be applied in the same manner even when swinging counterclockwise.

  The expressions (2) and (3) may express the same contents as follows. That is, the time interval sequence by the difference obtained by subtracting the reception interval sequence I_r (i) (i = 1, 2,..., N-1) from the transmission interval sequence I_t (i) (i = 1, 2,..., N-1). That is, assuming that the location where the sign is inverted for the first time in I_t (i) −I_r (i) (i = 1, 2,..., N−1) is the i-th position, [1] RD = D (i) if reversed to [2], on the contrary, if the sign is reversed from negative to positive by the sign inversion, RD = D (i) + 180 °, that is, RD is the reverse direction of D (i) You may ask for it. In this method, the first 180 ° result is automatically used even if the swing is 180 ° or more by detecting the portion where the sign is reversed first.

  In addition, it can be used for error detection of the direction estimation by performing a 360 ° swing and confirming whether or not the sign inversion portion is in the opposite direction at the first time and the second time.

  FIG. 6 shows a procedure sequence for estimating the relative direction from the search-side terminal 10 to the search-side terminal 20. Further, a flowchart of each step of the search side terminal 10 in the procedure sequence is shown in FIG. 7, and a flowchart of each step of the search side terminal 20 is shown in FIG. Procedures (1) to (14) are numbered in the procedures of each terminal itself and between the terminals shown in FIG. 6. In the explanation of the corresponding steps, the procedure (i ) Referenced as [i = 1-14].

  First, the procedure sequence of FIG. 6 will be described. In the procedure (1), when the user presses the button of the input unit 13 on the search side terminal 10, the relative direction estimation is started, for example, by starting a corresponding application on the terminal. In step (2), the searchee side terminal 20 is notified of the start of relative direction estimation via wireless communication, and an approval reply (ACK) is received. In step (3), the sound wave setting / transmission unit 15 determines the transmission interval of the pulse sound wave. As described above, the pulse sound wave and its transmission interval are a preferred embodiment of the transmission sound wave, and more generally, a sound wave set with a time change including equivalent information is determined as the transmission sound wave.

  In step (4), information on the determined transmission interval (or more generally time change) is wirelessly transmitted to the searched terminal 20. Also, in the transmission, information on the frequency band of each pulse (this information is also included in more general time change information so that the sound wave reception / identification unit 22 can identify the transmission sound wave from the search side terminal 10 from the received sound wave. ) Is also sent. The searched-side terminal 20 returns a reception confirmation message (ACK) and proceeds to step (5), where the sound wave reception / identification unit 22 activates the microphone and starts sound wave reception, that is, recording.

  Upon receiving the reception confirmation (ACK), the search-side terminal 10 informs the search-side terminal 10 that the user presses the button on the input unit 13 to start the direction estimating swing operation in step (6). Add swing motion. Along with the swing operation, a sound wave is transmitted by the sound wave setting / transmission unit 15 in the procedure (7), and at the same time, the search side terminal 10 that is changing due to the swing operation at each time point of the sound wave generation in the procedure (8). The orientation acquisition unit 12 acquires the orientation.

  By performing the procedure (7) and the procedure (8) started by pressing the button of the procedure (6) at the same time as the start of the swing after the procedure (6), each sound wave pulse transmission time (generally transmission) The time of interest in the time variation of the sound wave) and the orientation of the terminal at each time. When the swing is finished, in step (9), the user presses the button of the input unit 13 to notify the search side terminal 10 of the end of the swing operation. In the procedure (9), the search-side terminal 10 may automatically determine whether or not the transmission-side sound wave has been transmitted or after a predetermined time.

  In step (10), the search-side terminal 10 notifies the searched-side terminal 20 of the end of the relative direction estimation by wireless communication, and the searched-side terminal 20 acknowledges (ACK), and then in step (11) the microphone To stop recording (sound wave reception). Further, in step (12), the searched-side terminal 20 receives and identifies the sound wave from the information such as the transmission interval and frequency received in step (4) and the recorded data in steps (5) to (11). The reception interval is calculated by the unit 22.

  The reception interval calculated in step (13) is wirelessly transmitted to the search side terminal 10, and an acknowledgment message (ACK) is returned. In step (14), the search-side terminal 10 estimates the direction of the searched-side terminal 20 using the transmission interval, the reception interval, and the terminal direction at each time point.

  In the present invention, as described above, the search side terminal 10 and the searched side terminal 20 perform the synchronization process so that a period including a time period in which sound wave transmission is performed and a period not including any extra time as much as possible is used. Since the recording between 5) and (11) is performed, there is an effect that it becomes easy for the sound receiving / identifying unit 22 to identify and extract the sound corresponding to the transmitted sound wave from the recording on the searched terminal 20 side.

  Further, FIG. 7 which is a flowchart of each step of the search side terminal 10 in the sequence of FIG. 6 will be described. When the relative direction estimation starts in step S0, the user presses the button of the input unit 13 in step S1 [procedure (1)]. In step S2 [Procedure (2)], the searchee side terminal 20 is notified by radio of the start of relative direction estimation and prompts the synchronization of the process. In step S3 [Procedure (3)], the sound wave setting / transmission unit 15 determines a transmission interval and a use frequency (generally, a time change set in the transmission sound wave). In Step S4 [Procedure (4)], the determination information (transmission) (Interval etc.) is notified to the searched-side terminal 20 by radio.

  Proceeding to step S5 [Procedure (6)], the input unit 13 detects that the user has pressed the button, which is a signal for starting the swing operation. Simultaneously with step S5, the user applies a swing motion to the search side terminal 10, and at step S6 [procedures (6) and (7)], performs sound wave transmission and terminal orientation acquisition. The user who has finished the swing operation presses the button of the input unit 13 in step S7 [Procedure (9)] to notify the search-side terminal 10 of the end of the swing operation. As described above, step S7 may be automatically performed after the end of the sound wave transmission, instead of being pressed by the user.

  In step S8 [Procedure (10)], the end of the swing operation of relative direction estimation is transmitted to the searched terminal 20 by wireless communication. In the step [Procedure (13)], the reception interval calculated by the searchee side terminal 20 is transmitted by radio, and the search side terminal 10 receives it. In step S10 [Procedure (14)], the relative direction of the searched terminal 20 is estimated based on the transmission interval, reception interval, and acquisition direction, and the flow ends in step S11. If no button press is detected in steps S5, S7, and S9, or if necessary information is not transmitted from the searchee side terminal 20, it is determined that an error has occurred in the flow, and the step is repeated. Start over from S1.

  6 and 7, the input unit 13 may be another interface such as a touch panel, and similarly input detection such as various start cues. Used as As an interface, after the user input is detected in step (6), the swing operation can be started quickly and smoothly without adding any extra operation to the search side terminal 10; An interface that can quickly and smoothly transmit user input to the terminal without adding any operation is preferable, and button pressing is an example.

  Furthermore, FIG. 8 which is a flowchart of each step of the searchee side terminal 20 in the sequence of FIG. 6 will be described. When the relative direction estimation is started in step S20, first, in step S21 [Procedure (2)], a relative direction start notification, that is, a synchronization request is received from the search side terminal 10, preparation is made to respond to the relative direction estimation, and a response is returned. To do. In step S22 [Procedure (4)], information such as a transmission interval and a used frequency is wirelessly received from the search side terminal 10, and the information is passed to the sound wave reception / identification unit 22 for subsequent identification processing. Thereafter, in step S23 [Procedure (5)], the sound wave reception / identification unit 22 activates the microphone and starts sound wave reception, that is, recording. In step S24 [Procedure (10)], the search terminal 10 receives the notification of the end of the swing operation and the sound wave transmission in the relative direction estimation, responds, and synchronizes the state. That is, the process proceeds to Step S25 [Procedure (11)], the microphone activated in the sound wave reception / identification unit 22 is stopped, and the recording is ended.

  Proceeding to step S26 [procedure (12)], the sound wave reception / identification unit 22 calculates a reception interval from the recorded data using the information received in step S22. Proceeding to step S27 [procedure (13)] and notifying the search side terminal 10 of the calculation result, the flow ends in step S28. In addition, if information indicating that the relative direction estimation flow is proceeding smoothly from the search-side terminal 10 in steps S22 and S24 in the flow cannot be received, an error has occurred, and the process returns to step S21 again. .

As described above, according to the present invention, new infrastructure equipment and special hardware are not required, and the relative direction between terminals can be estimated using a general mobile terminal. Next, various applications and services that can be realized using the present invention will be introduced. Each introduction is based on the following assumptions.
(Prerequisite A) The application is running on the non-search side terminal
(Assumption B) Wireless communication between terminals In the following description, examples of means for achieving these assumptions will also be described.

(Example 1)
Partner identification support in off-line meeting
When meeting with people who have become friends on the network such as SNS (Social Network Service) off-site, there is no acquaintance, so if there are several people who are unrelated to the meeting place, specify the meeting partner It is not easy. At that time, the relative direction with the opponent is provided to assist the identification of the opponent.
(Meeting means for Assumption A) The information on the meeting place and the meeting date and time is taken in from the SNS to the portable terminal. Monitor the GPS location information acquired on your mobile device, and launch the app when you detect that you are near a meeting place. Or, when the meeting date and time approaches, start the application.
(Measuring method for Premise B) Import the meeting ID from SNS into the mobile terminal. Establish a wireless communication link with a terminal that has the same ID when the app starts.

(Example 2)
Part-time workers who register through the Internet, such as partner-specific support Shotworks (http://shotworks.yahoo.co.jp/guest) at the meeting of Internet-registered part-time workers, often have different locations and work colleagues. When waiting for such a part-time job, support partner identification as in (Example 1).
(Meeting means of Assumption A) Information on the meeting place and the date and time of meeting is taken into the mobile terminal from the registration site. Monitor the GPS location information acquired on your mobile device, and launch the app when you detect that you are near a meeting place. Or, when the meeting date and time approaches, start the application.
(Measuring method for Assumption B) Import the meeting ID from the registration site to the mobile terminal. Establish a wireless communication link with a terminal that has the same ID when the app starts.

(Example 3)
Identifying the partner in meeting with an acquaintance When meeting with a family member or friend, even if you know the face of the other party, it may be difficult to identify the partner if the meeting place is crowded or the prospect is poor. At that time, the partner identification is supported in the same manner as in (Example 1).
(Measuring method for assumption A) Start manually.
(Measuring method for Premise B) Share the ID via phone or email, and import the shared ID to the mobile device. Establish a wireless communication link with a terminal that has the same ID when the app starts.

(Example 4)
Delivery service at restaurants If there is no product when ordering at the cash register, such as McDonald's (registered trademark) or Mosberga (registered trademark), give the customer a number tag and as soon as the product is completed, the clerk will ask the customer with the target number tag There is a case of searching and delivering visually. It may take time for the clerk to search for the target number tag, such as when the seats span multiple floors. In such a case, the proposed method is used to support the target customer discovery.
(Measuring means for Assumption A) Electronic money is used at the time of accounting, and the application is activated with accounting using electronic money as a trigger.
(Measuring means for Assumption B) Take in an ID when accounting for electronic money and establish a wireless communication link with a terminal with the same ID.

(Example 5)
Finding victims When discovering victims buried under rubble at the time of the disaster, support discovery using the proposed method.
(Measuring method for assumption A) Broadcast disaster information from the base station near the disaster area and launch the app.
(Measuring means for Assumption B) Share the ID through the above broadcast.
Note that in this (example 5), various responses from the searchee side terminal 20 (ACK shown in FIG. 6 and the like) are automatically performed without waiting for user input.

  In addition, the following applications and services can be realized by adding the functions of the non-search side terminal to fixed PCs, devices, and things.

(Example 6)
Property discovery When a property such as a remote control or a music player is not found in a room or dropped outdoors, discovery is facilitated by using the proposed method.
(Measuring means for Assumption A) The application is started using wireless communication.
(Measuring method for Premise B) Pre-set (because it is a property).

(Example 7)
Illegal wireless LAN AP (access point) discovery / When detecting the existence of a specific illegal wireless LAN AP, SSID (Service Set ID) information can be acquired, but the radio waves are not visible, so the illegal wireless LAN AP is discovered It may not be easy. Also, for example, even if there are two wireless LAN APs in front of you, in order to identify which one is an illegal wireless LAN AP, you need to refer to the device settings or turn off one of the power supplies. Cost. In such a case, the proposed method is used.
(Measuring means for Assumption A) The application is started using wireless communication.
(Measuring method for Assumption B) Connect to the wireless LAN AP from the acquired SSID.

(Example 8)
Robot guidance service When the robot guidance service spreads, people move to the position of the robot and receive the service, but when clicking on the web screen of the robot guidance service on the mobile phone, the robot will come in front of you Convenient. At that time, the robot identifies the target person using the proposed method.
(Measuring method for Premise A) Triggered by a click action on the web, a signal is sent from the web server to the robot, and the application is started.
(Measuring method for Assumption B) Import the ID from the web into the mobile phone and establish a wireless communication link with the other party with the same ID.

  DESCRIPTION OF SYMBOLS 10 ... Search side terminal, 11 ... Relative direction estimation part, 12 ... Direction acquisition part, 14 ... Wireless communication part, 15 ... Sound wave setting / transmission part, 20 ... Searched side terminal, 21 ... Wireless communication part, 22 ... Sound wave reception・ Identifier

Claims (10)

A relative direction estimation method for estimating a relative direction of a searched terminal from a searching terminal,
A notification step of notifying the searchee side terminal from the search side terminal using wireless communication information indicating that the estimation is started and information on the first time change set in the sound wave used for the estimation;
A recording start stage in which the searchee terminal starts recording after the notification stage;
After the notification step, an exercise step in which a predetermined exercise for changing the orientation of the terminal is applied to the searching terminal;
A sound wave transmitting step in which the search side terminal transmits a sound wave in which the first time change is set simultaneously with the exercise step;
A direction acquisition step of acquiring a time change of the direction of the search terminal in the exercise phase;
The end of the exercise stage is notified from the search side terminal to the searched side terminal using wireless communication, and the recording end stage in which the searched terminal ends the started recording;
After the recording end stage, the searched terminal uses the notified first time change information to extract a portion having a strong correlation with the first time change from the recording, and the time of the portion Wirelessly transmitting information of a second time change that is a change to the search side terminal;
A step of the search side terminal estimating the relative direction based on the first time change information, the second time change information, and the direction time change acquired in the direction acquisition step. A relative direction estimation method characterized by: The first time change is a time change in which the sound wave to be transmitted is a plurality of pulsed sound waves provided with a first time interval sequence;
A portion where the volume increase is seen in a pulse shape at an interval where the second time change is more correlated with the first time interval sequence than the recording is extracted, and a plurality of pulse-like volume increase times at the location are extracted. The relative direction estimation method according to claim 1, wherein the relative direction estimation method is a time change as a second time interval sequence which is a sequence of intervals. The first time change is a time change in which the sound wave to be transmitted is a predetermined frequency band and is a plurality of pulsed sound waves provided with a first time interval sequence,
A portion where the volume change is seen in a pulse form at an interval having a strong correlation with the first time interval sequence from the recording and the second time change is substantially coincident with the predetermined frequency band is extracted. The relative direction estimation method according to claim 1, wherein the relative direction estimation method is a time change as a second time interval sequence which is a sequence of time intervals of a plurality of pulse-like volume increases.   The estimation step is acquired in the orientation acquisition step using a time corresponding to a place where a sign is inverted in a time interval sequence formed by subtracting the second time interval sequence from the first time interval sequence. The direction corresponding to the time is obtained from the time change of the determined direction, and if the sign inversion is negative, the direction is estimated as the relative direction, and if the sign inversion is positive, the direction The relative direction estimation method according to claim 2, wherein a reverse direction is estimated as the relative direction.   The relative direction estimation method according to claim 2, wherein the first time interval sequence is determined using a random number.   6. The swing motion according to claim 1, wherein the predetermined motion is a substantially semicircular and substantially horizontal swing motion with a substantially constant radius centered on a stationary position of the search side terminal. The relative direction estimation method described.   The relative direction estimation method according to claim 1, wherein the direction acquisition step acquires a time change in the direction of the search terminal using a geomagnetic sensor.   The relative direction estimation method according to claim 1, wherein the relative direction estimation method is used for waiting between a user of the search side terminal and a user of the searched side terminal. A search-side terminal that estimates a relative direction of a searched-side terminal;
A sound wave setting / transmission unit for transmitting a sound wave with a time change set;
An orientation acquisition unit for acquiring the orientation of the search side terminal;
A wireless communication unit that wirelessly communicates with the searched terminal;
A relative direction estimation unit that estimates a relative direction in which the searched terminal exists,
After notifying the to-be-searched side terminal of the information to start the estimation and the first time change information to be used for the estimation, the to-be-searched side terminal starts receiving the sound wave. The sound wave setting / transmission unit transmits the sound wave in which the first time change is set simultaneously with a predetermined motion applied to change the direction of the search side terminal, and the direction acquisition unit transmits the sound wave during the transmission. The terminal orientation is acquired and identified as a location having a stronger correlation with the first time change than the sound wave received by the searchee terminal based on the first time change information in the notification. Information on the second time change, which is the time change at the location, is sent back via the wireless communication unit, and the relative direction estimation unit is configured to send the first time change information, the second time change information, and the Get while sending Searching side terminal and estimates the relative direction the based on the orientation of the search terminal. A searched terminal whose relative direction is estimated by a searching terminal;
A sound wave reception / identification unit that receives sound waves and identifies temporal changes of the sound waves;
A wireless communication unit that wirelessly communicates with the search side terminal;
After the information on the start of the estimation and the information on the first time change set in the sound wave used for the estimation are notified from the search side terminal via the wireless communication unit, the sound wave reception / identification unit Starts reception, transmits a sound wave in which the first time change is set simultaneously with a predetermined motion applied so that the search terminal changes the direction of the search terminal, and the direction of the search terminal during the transmission The sound wave reception / identification unit identifies the portion having a strong correlation with the first time change based on the information on the first time change in the notification, and identifies the time of the portion. A second time change that is a change is obtained, information on the second time change is returned to the search side terminal via the wireless communication unit, and the information on the first time change and the information on the first time change are returned to the search side terminal. Second time change information and previous The search terminal, characterized in that to estimate the relative direction based on the orientation of the acquired during transmission the search terminal.

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