Detection device and program

Abstract

To provide a detection device and a program for accurately detecting the number of persons present around.SOLUTION: The detection device 100 according to the present disclosure includes the reception unit 101 that receives a radio wave including a device identifier transmitted from a device present around the detection device 100 in a predetermined cycle, the calculation unit 102 that acquires, for each device identifier, information indicating a reception status in each cycle of the radio wave received by the reception unit 101 in a predetermined period, groups the device identifiers based on a temporal change in the reception status, and calculates the number of groups, and the storage unit 103 that stores the number of groups calculated by the calculation unit 102.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a detection device and a program. [Background technology]

[0002] There are technologies for detecting the number of people present in a predetermined location such as a vehicle. For example, Patent Document 1 discloses a technology for detecting the number of passengers in a vehicle based on radio waves transmitted from a terminal device such as a smartphone carried by the vehicle occupants. The technology disclosed in Patent Document 1 makes it possible to detect the number of passengers in a vehicle without the user having to perform any special operation. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-41177 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology disclosed in Patent Document 1 does not necessarily enable the number of people in a vehicle to be detected with sufficient accuracy. For example, the technology disclosed in Patent Document 1 does not fully consider accurately detecting the number of people in a situation where one person carries multiple terminal devices.

[0005] In view of the above-described problems, an object of the present disclosure is to provide a detection device and a program that accurately detect the number of people present in the vicinity. [Means for solving the problem]

[0006] The detection device according to the present disclosure comprises: a receiving unit that receives, at a predetermined interval, radio waves including device identifiers transmitted from devices present in the vicinity; a calculation unit that acquires, for each device identifier, information indicating a reception status in each period of the radio waves received by the receiving unit during a predetermined period, groups the device identifiers based on a change over time in the reception status, and calculates the number of groups; a storage unit that stores the number of groups calculated by the calculation unit; It is equipped with the following.

[0007] The program according to the present disclosure is a receiving step of receiving, at a predetermined interval, radio waves including device identifiers transmitted from devices present in the vicinity; a calculation step of acquiring, for each device identifier, information indicating a reception status in each cycle of the radio waves received in the receiving step during a predetermined period, grouping the device identifiers based on a temporal change in the reception status, and calculating the number of groups; and a storage step of storing the number of groups calculated in the calculation step. [Effects of the Invention]

[0008] The detection device and program according to the present disclosure can accurately detect the number of people present in the vicinity. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a functional block diagram of the detection device. [Figure 2] FIG. 2 is a flowchart showing the processing flow of the detection device. [Figure 3] FIG. 3 shows an example of a vehicle configuration. [Figure 4] FIG. 4 is a functional block diagram of the detection device. [Figure 5] FIG. 5 is an example of the terminal identification information history table. [Figure 6] FIG. 6 is an example of the terminal identification information history table. [Figure 7] FIG. 7 is a flowchart showing the flow of processing by the detection device. [Figure 8] FIG. 8 is a flowchart showing the flow of processing by the detection device. [Figure 9] FIG. 9 shows an example of warning information displayed on the display unit. [Figure 10] FIG. 10 is a diagram showing an example of the excess capacity information list created in S250 of the flowcharts of FIGS. [Figure 11] FIG. 11 is an example of displaying over-capacity information, showing the over-capacity information list in a table format. [Figure 12] FIG. 12 is a diagram showing an example in which a map and over-capacity information are displayed superimposed on the display unit. [Figure 13] FIG. 13 is an example of the terminal identification information history table. [Figure 14] FIG. 14 is an example of the terminal identification information history table. [Figure 15] FIG. 15 is a diagram (graph) showing an example of a change in received signal strength before and after a vehicle starts traveling. [Figure 16] FIG. 16 is a flowchart showing the flow of processing by the detection device. [Figure 17] FIG. 17 shows an example of signal strength time series data corresponding to the graph of FIG. [Figure 18] FIG. 18 is a diagram illustrating an example of distance time-series data. [Figure 19] FIG. 19 is an example of a sequence diagram showing processing between a detection device and a plurality of mobile terminals. [Figure 20] FIG. 20 is a diagram showing an example of a category list. [Figure 21] FIG. 21 is a diagram showing an example of a model name list. [Figure 22] FIG. 22 is a flowchart showing the flow of processing by the detection device. [Figure 23] FIG. 23 is a flowchart showing the flow of processing by the detection device. [Figure 24] FIG. 24 is an example of a terminal identification information history table. [Figure 25]FIG. 25 is a flowchart showing the processing of the detection device when the vehicle is running. [Figure 26] FIG. 26 shows an example of the configuration of a detection system. [Figure 27] FIG. 27 is a diagram for explaining the installation location of the detection device. [Figure 28] FIG. 28 is a diagram showing an example of changes in received signal strength detected by a detection device installed near the entrance and recorded in the terminal identification information history table of the detection device. [Figure 29] FIG. 29 shows an example of signal strength time series data corresponding to the graph of FIG. [Figure 30] FIG. 30 is a flowchart showing the flow of processing by the detection device. [Figure 31] FIG. 31 is a flowchart showing the flow of control processing in the management device. [Figure 32] FIG. 32 is a diagram for explaining the installation location of the detection device in this modified example. [Figure 33] FIG. 33 is a diagram for explaining the installation location of the detection device in this modified example. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In each drawing, the same or corresponding elements are designated by the same reference numerals. For clarity of explanation, duplicated explanations will be omitted as necessary.

[0011] <Basic Example> First, a detection device 100 according to the present disclosure will be described. This embodiment is a basic embodiment for the embodiments described later. Here, the basic embodiment according to the present disclosure will be described, and in the multiple embodiments shown below, more detailed configuration examples and operation examples will be described.

[0012] 1 is a functional block diagram of a detection device 100 according to this embodiment. The detection device 100 includes a receiving unit 101, a calculating unit 102, and a storage unit 103.

[0013] The receiving unit 101 receives radio waves including device identifiers transmitted from surrounding devices at a predetermined cycle. The calculating unit 102 acquires, for each device identifier, information indicating the reception status of the radio waves received by the receiving unit 101 during each cycle of the predetermined period, groups the device identifiers based on changes in the reception status over time, and calculates the number of groups. More specifically, the calculating unit 102 groups multiple device identifiers whose changes in the reception status over time are similar, and calculates the number of groups. The storage unit 103 stores the number of groups calculated by the calculating unit 102.

[0014] The detection device 100 includes a processor and a memory, which are not shown in the figure. A computer program implementing the processing according to the present disclosure is stored in a storage unit 103, which is a storage device. The processor can load the computer program from the storage unit 103 into the memory and execute the computer program. In this way, the processor realizes the function of the calculation unit 102.

[0015] Alternatively, the calculation unit 102 may be realized by dedicated hardware. Furthermore, some or all of the components of the detection device 100 may be realized by general-purpose or dedicated circuits, processors, etc., or a combination of these. These may be configured by a single chip, or by multiple chips connected via a bus. Some or all of the components of the detection device 100 may be realized by a combination of the above-mentioned circuits, etc., and programs. Furthermore, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an FPGA (Field-Programmable Gate Array), a quantum processor (quantum computer control chip), etc., may be used as the processor.

[0016] The above-described configuration of the detection device 100 is merely an example and may be modified as appropriate. For example, when some or all of the components of the detection device 100 are realized by multiple information processing devices, circuits, etc., the multiple information processing devices, circuits, etc. may be centrally or decentralized. For example, the information processing devices, circuits, etc. may be realized as a client-server system, a cloud computing system, or the like, in a form in which each is connected via a communication network. Furthermore, some functions of the detection device 100 may be provided in a SaaS (Software as a Service) format.

[0017] The processing of the detection device 100 in this embodiment will be described with reference to Fig. 2. Fig. 2 is a flowchart showing the processing flow of the detection device 100.

[0018] In S1, the receiving unit 101 receives radio waves including device identifiers transmitted from surrounding devices at a predetermined interval. Note that there may be only one surrounding device, but typically there are multiple surrounding devices. Each device transmits radio waves including its respective device identifier, and the receiving unit 101 receives these radio waves.

[0019] In S2, the calculation unit 102 acquires, for each device identifier, information indicating the reception status in each cycle of the radio waves received by the reception unit 101 during a predetermined period from the reception unit 101. The following are examples of "information indicating the reception status," but the present invention is not limited to these.

[0020] Example 1) At time A1 (the A1th period), a radio wave including a device identifier X1 is received. Example 2) At time A2, no radio waves containing device identifier X1 were received. Example 3) At time A3, radio waves including device identifier X2 are received with a signal strength that satisfies a predetermined condition (for example, received with a signal strength equal to or greater than a predetermined signal strength). Example 4) At time A4, radio waves including device identifier X2 were not received with a signal strength that satisfied a predetermined condition (for example, not received with a signal strength equal to or greater than a predetermined level). Example 5) At time A5, a radio wave including device identifier X3 is received with signal strength E5.

[0021] In S3, the calculation unit 102 groups the device identifiers based on the change in reception status over time. More specifically, the calculation unit 102 groups a plurality of device identifiers whose change in reception status over time is similar. The following are examples of "whose change in reception status over time is similar," but the present invention is not limited to these.

[0022] Example 1) In a predetermined period, the time difference between the point A1 (time A1) when radio waves including device identifier X1 are first received and the point A2 (time A2) when radio waves including device identifier X2 are first received is small (for example, the time difference is equal to or less than a predetermined value).

[0023] Example 2) In a predetermined period, the time difference between the time A1 when radio waves including device identifier X1 were last received and the time A2 when radio waves including device identifier X2 were last received is small (for example, the time difference is equal to or less than a predetermined value).

[0024] Example 3) In a predetermined period, the time difference between the first point A1 at which radio waves including device identifier X1 are received consecutively a predetermined number of times or more and the first point A2 at which radio waves including device identifier X2 are received consecutively a predetermined number of times or more is small (for example, the time difference is equal to or less than a predetermined value).

[0025] Example 4) In a predetermined period, the time difference between the first point A1 at which radio waves including device identifier X1 are received consecutively at a predetermined signal strength or greater a predetermined number of times and the first point A2 at which radio waves including device identifier X2 are received consecutively at a predetermined signal strength or greater a predetermined number of times is small (for example, the time difference is less than a predetermined value).

[0026] Example 5) In a specified period of time, the time difference between the last point A1 at which radio waves including device identifier X1 were received with a signal strength equal to or greater than a specified value and the last point A2 at which radio waves including device identifier X2 were received with a signal strength equal to or greater than a specified value is small (for example, the time difference is equal to or less than a specified value).

[0027] Example 6) Time-series data of signal strength of radio waves containing device identifier X1 is similar to time-series data of signal strength of radio waves containing device identifier X2. In other words, the time-varying patterns of signal strength are similar between multiple devices. More specifically, an index indicating the similarity between the two satisfies a predetermined standard (for example, the similarity is equal to or greater than a predetermined value).

[0028] Example 7) Time series data of the temporal difference in signal strength of radio waves containing device identifier X1 is similar to time series data of the temporal difference in signal strength of radio waves containing device identifier X2. More specifically, an index indicating the similarity between the two satisfies a predetermined standard (e.g., the similarity is equal to or greater than a predetermined value). For example, the temporal difference in signal strength may be the difference between the signal strength at time A1 and the signal strength at time A2, which is the next period after time A1.

[0029] Example 8) In a predetermined period, the time difference between time A1 when the signal strength of radio waves including device identifier X1 reaches a maximum or greatest value and time A2 when the signal strength of radio waves including device identifier X2 reaches a maximum or greatest value is small (e.g., the time difference is equal to or less than a predetermined value). Alternatively, for example, multiple times (e.g., A1, A2, A3) when the signal strength of device identifier X1 reaches a maximum and multiple times (e.g., A11, A12, A13) when the signal strength of device identifier X2 reaches a maximum may be calculated, and the time difference between each of the chronologically corresponding times (e.g., the time difference between A1 and A11, the time difference between A2 and A12, and the time difference between A3 and A13) may be calculated. If the distribution of these multiple time differences satisfies a predetermined criterion (e.g., the maximum value, average value, median, etc. are equal to or less than a predetermined value), the two may be deemed to be "similar."

[0030] Example 9) In a predetermined period, the difference between E1, which is the maximum or maximum value of the signal strength of radio waves including device identifier X1, and E2, which is the maximum or maximum value of the signal strength of radio waves including device identifier X2, is small (e.g., the difference is equal to or less than a predetermined value). Alternatively, for example, multiple maximum values ​​of the signal strength of device identifier X1 (e.g., E1, E2, E3) and multiple maximum values ​​of the signal strength of device identifier X2 (e.g., E11, E12, E13) may be calculated, and the differences between the maximum values ​​corresponding to time (e.g., the difference between E1 and E11, the difference between E2 and E12, and the difference between E3 and E13) may be calculated, and the distribution of these multiple differences (absolute values ​​of the differences) may be determined to satisfy a predetermined criterion (e.g., the maximum value, average value, median value, etc. are equal to or less than a predetermined value).

[0031] In both example 6) and example 7), it can be said that "time-series data based on the signal strength of radio waves including device identifier X1 is similar to time-series data based on the signal strength of radio waves including device identifier X2." Furthermore, the calculation unit 102 may group three or more device identifiers into one group. Furthermore, when the receiving unit 101 receives only one device identifier, the calculation unit 102 may group the device identifier into one group.

[0032] In S4, the calculation unit 102 calculates the number of groups. In S5, the storage unit 103 stores the number of groups calculated by the calculation unit 102.

[0033] With this configuration, the detection device 100 according to this embodiment can accurately detect the number of people present in the vicinity.

[0034] Example 1 Next, a description will be given of Example 1. Example 1 is a specific example of the basic example described above.

[0035] In this embodiment, the number of passengers in the vehicle is detected. First, the configuration of the vehicle 3 in this embodiment and the users of the vehicle 3 will be described.

[0036] Fig. 3 shows an example of the configuration of a vehicle 3 according to this embodiment. As shown in Fig. 3, the vehicle 3 includes a detection device 1. The detection device 1 also includes a short-range communication unit 11 capable of communicating by short-range communication.

[0037] In this embodiment, an electric kick scooter will be used as an example of the vehicle 3, but the present invention is not limited to this. The vehicle 3 may be any vehicle that prohibits passengers from exceeding its capacity, such as a bicycle, electric bicycle, electric cart, motorcycle, or automobile. The vehicle 3 may have two wheels, or three or more wheels, and the number of wheels is optional. The vehicle 3 may or may not have a door.

[0038] Generally, it is highly likely that a user of the vehicle 3 carries a mobile terminal (for example, a smartphone, a tablet terminal, a smartwatch, etc.). In the following, as shown in FIG. 3, an example will be described in which the user carries a smartphone in a pocket or the like as the mobile terminal 5.

[0039] Each mobile terminal 5 carried by a user can communicate with other devices (e.g., earphones, headsets, car navigation systems, etc.) through short-range communication. For example, Bluetooth (registered trademark, the same applies hereinafter) may be used as a short-range communication technology, but this is not limiting. The mobile terminal 5 transmits terminal identification information (e.g., Bluetooth advertisement packets) at a predetermined interval. Through short-range communication, the detection device 1 can receive radio waves transmitted from a mobile terminal 5 located within a few meters of the detection device 1, but this distance is merely an example and is not limiting.

[0040] The terminal identification information includes at least an identifier (terminal identifier) ​​that is individually set for each terminal, and may also include information such as a transmission output value. The detection device 1 of the vehicle 3 receives the terminal identification information transmitted from each mobile terminal 5. Note that the terminal identifier is also called a device identifier, and the terminal identification information is also called device identification information.

[0041] 4 is a functional block diagram of the detection device 1 in this embodiment. The detection device 1 is mounted on a vehicle 3. The detection device 1 includes a control unit 10, a short-range communication unit 11, a vehicle communication unit 12, a timing unit 13, a memory unit 14, a display unit 15, an operation unit 16, an audio output unit 17, a location information identification unit 18, and a communication unit 19.

[0042] The vehicle 3 also includes a vehicle speed detection unit 31 and a propulsion control unit 32. The vehicle speed detection unit 31 outputs information (speed information) indicating the speed of the vehicle 3. The vehicle speed detection unit 31 may detect the speed based on the number of rotations of the wheels, or may detect the speed based on a change over time in the position information identified by the position information identification unit 18.

[0043] The propulsion control unit 32 controls the propulsion state of the vehicle 3. Specifically, the propulsion control unit 32 controls the motor, brakes, etc. of the vehicle 3 to keep the speed of the vehicle 3 constant or to stop the vehicle 3.

[0044] The short-range communication unit 11 is an example of the above-mentioned receiving unit 101. The short-range communication unit 11 receives, at a predetermined cycle, radio waves including at least a terminal identifier (device identifier) ​​transmitted from a mobile terminal 5 (device) present in the vicinity.

[0045] For example, the short-range communication unit 11 periodically receives terminal identification information periodically transmitted by the mobile terminal 5 at a detection period (predetermined period) T1. The transmission period of the mobile terminal 5 may differ for each mobile terminal, but is, for example, about 100 milliseconds. In this embodiment, unless otherwise specified, the detection period T1 used by the short-range communication unit 11 is 200 milliseconds, but is of course not limited to this. The detection period T1 may be, for example, 500 milliseconds.

[0046] The short-range communication unit 11 is equipped with an antenna and is capable of receiving radio waves transmitted from a mobile terminal 5 that is present at least within a predetermined distance from the antenna. This predetermined distance may be, for example, 3 m or 5 m, but is of course not limited to this value. In this embodiment, the short-range communication unit 11 is set so as to be able to receive radio waves from the mobile terminal 5 even when the mobile terminal 5 is located outside the vehicle 3.

[0047] The vehicle communication unit 12 communicates with the vehicle speed detection unit 31 to acquire speed information of the vehicle 3. The vehicle communication unit 12 also communicates with the propulsion control unit 32 to change the speed of the vehicle 3 or stop the vehicle 3. The communication between the vehicle speed detection unit 31 and the vehicle communication unit 12, and the communication between the propulsion control unit 32 and the vehicle communication unit 12 may be wireless or wired.

[0048] The clock unit 13 outputs the current date and time (time), which is measured in units of at least seconds, but may be measured in units of milliseconds.

[0049] The storage unit 14 is an example of the storage unit 103 described above. The storage unit 14 stores the number of groups calculated by the control unit 10 (calculation unit). The storage unit 14 also stores various data and programs, and records a terminal identification information history table, which will be described later. At least a portion of the storage unit 14 is configured as a non-volatile memory so that necessary data is retained even when the power to the vehicle 3 is turned off.

[0050] The display unit 15 is an interface for displaying the speed of the vehicle 3 and warning information. The operation unit 16 is an interface for receiving operations from the user. The display unit 15 and the operation unit 16 may be integrated into one unit using a touch panel. The audio output unit 17 outputs a warning information message by voice or outputs a warning sound.

[0051] The location information identification unit 18 is composed of a GNSS (Global Navigation Satellite System) receiver or the like, and acquires current location information (latitude, longitude) of the vehicle 3. The communication unit 19 (long-distance communication unit) communicates with an external server or the like via a communication means (for example, a mobile phone network or the Internet).

[0052] The control unit 10 is an example of the calculation unit 102 described above. The control unit 10 has a function of the calculation unit 102, which acquires, for each terminal identifier, information indicating the reception status in each cycle of radio waves received by the short-range communication unit 11 (receiving unit 101) during a predetermined period, groups the terminal identifiers based on temporal changes in the reception status, and calculates the number of groups. More specifically, the control unit 10 uses, as the information indicating the reception status, information indicating whether the short-range communication unit 11 has received radio waves including a terminal identifier, or information indicating whether the short-range communication unit 11 has received radio waves including a terminal identifier with a signal strength that satisfies a predetermined condition. Typically, the predetermined condition may be that the signal strength is equal to or greater than a predetermined value, but may also be that the signal strength is equal to or greater than a first predetermined value and less than a second predetermined value (the second predetermined value being greater than the first predetermined value).

[0053] Furthermore, the control unit 10 identifies, for each terminal identifier, at least one of the time when the short-range communication unit 11 received the radio wave and the time when the signal strength satisfied a predetermined condition, and groups the terminal identifiers by regarding multiple terminal identifiers whose identified time difference is within a predetermined time as similar and placing them in the same group. The control unit 10 will be described in detail below.

[0054] The control unit 10 records the terminal identification information received by the short-range communication unit 11 every detection period T2 (for example, 1 second) in a terminal identification information history table in the storage unit 14 together with the date and time obtained from the clock unit 13. That is, one record is added to the terminal identification information history table every detection period T2. The detection period T2 is equal to or longer than the detection period T1, but may be the same as the detection period T1.

[0055] The control unit 10 also records the terminal identification information received before the vehicle 3 starts traveling in the terminal identification information history table. For example, the control unit 10 may always record the terminal identification information in the terminal identification information history table while the control unit 10 is operable (while power is being supplied). The control unit 10 may record all received terminal identification information in the terminal identification information history table, or may record only terminal identification information whose received signal strength satisfies a predetermined condition (predetermined standard) (for example, -65 dBm or more).

[0056] For example, the conditions for the received signal strength to be recorded in the terminal identification information history table may be set so that information transmitted from a mobile terminal 5 within a predetermined distance (for example, within 2 m) from the vehicle 3 is recorded, but information transmitted from a mobile terminal 5 that is farther away than the predetermined distance is not recorded. Also, the conditions for the received signal strength may be set so that information transmitted from a mobile terminal 5 inside (on) the vehicle 3 is recorded, but information transmitted from a mobile terminal 5 outside the vehicle is not recorded, in other words, information transmitted from a mobile terminal 5 that is a distance away equivalent to the size of the vehicle 3 is recorded.

[0057] The control unit 10 may automatically delete from the terminal identification information history table any record whose reception time is more than a predetermined period (for example, 30 minutes) from the current time, for all records recorded in the terminal identification information history table.

[0058] 5 and 6 are examples of a terminal identification information history table. The reception time (reception date and time) is the date and time when the terminal identification information was received, and is recorded at least to the second, but may be recorded with a finer time resolution such as to the millisecond. The terminal identifier is a unique identifier (terminal ID) for each terminal that is written in the terminal identification information.

[0059] FIG. 5 is an example of a table in the case where one user riding in vehicle 3 carries two mobile terminals 5. This figure also shows data from the time when the terminal identifier was first recorded in the terminal identification information history table. Note that, below, multiple different mobile terminals 5A, 5B, 5C, ..., 5N (N is a natural number) may be collectively referred to as "multiple mobile terminals 5," but the multiple mobile terminals 5 may be of different types. For example, mobile terminal 5A, which is a smartphone, and mobile terminal 5B, which is a tablet terminal, may be collectively referred to as multiple mobile terminals 5.

[0060] As shown in this figure, two mobile terminals 5 with terminal identifiers "1000" and "2000" are recorded in the table. Because both mobile terminals 5 are carried by the same user, the reception time at which recording of the two terminal identifiers began is the same (2023 / 09 / 14 10:35:00). Furthermore, the two terminal identifiers are subsequently recorded at the same time.

[0061] In this way, when one user carries multiple mobile terminals 5, the short-range communication unit 11 can receive signals from those mobile terminals 5 almost simultaneously, or the received signal strength will meet a predetermined standard, so there is a high possibility that recording of multiple terminal identifiers will begin at the same time.

[0062] On the other hand, Fig. 6 is an example of a table in the case where two users riding in a vehicle 3 each carry one mobile terminal 5. In the example of Fig. 6, one user carries mobile terminal 5A, and the other user carries mobile terminal 5B.

[0063] As shown in the figure, one user's mobile terminal 5A (terminal identifier "1000") started recording at "2023 / 09 / 14 10:35:00", and then another user's mobile terminal 5B (terminal identifier "2000") started recording at "2023 / 09 / 14 10:35:08". In other words, there is an 8-second difference between the recording start times of the two terminal identifiers.

[0064] When two users get on a vehicle 3, the timing of getting on often differs from person to person, so it is highly likely that the recording start time will differ depending on the terminal identifier. In other words, when multiple terminal identifiers are detected consecutively in the terminal identification information history table, by comparing the start times at which the terminal identifiers were detected, it is possible to determine whether one user is carrying multiple mobile terminals 5, or whether multiple users each carry a mobile terminal 5.

[0065] The processing of the detection device 1 in this embodiment will be described with reference to Figures 7 and 8. Figures 7 and 8 are flowcharts showing the flow of processing by the detection device 1.

[0066] In S100, the control unit 10 acquires speed information from the vehicle speed detection unit 31 via the vehicle communication unit 12 and determines whether the vehicle 3 has started traveling. For example, it may be determined that the vehicle 3 has started traveling when the speed is equal to or greater than a predetermined value (e.g., 2 km / h). Alternatively, it may be determined that the vehicle 3 has started traveling when a predetermined time (e.g., 1 minute) has elapsed while the speed of the vehicle 3 is equal to or greater than the predetermined value.

[0067] If the vehicle 3 has started traveling (S100: Yes), the process proceeds to S110. If the vehicle 3 has not started traveling (S100: No), the process returns to S100 and repeats the process.

[0068] In S110, the control unit 10 initializes the boarding list PL and the starting time list SL, and then proceeds to S120.

[0069] In S120, the control unit 10 acquires the current time from the clock unit 13, and then refers to the terminal identification information history table in the storage unit 14, and extracts all records whose reception time is within a predetermined period Q1 (e.g., 3 minutes) from the current time as the processing target records R1. In other words, the processing target records R1 are a set of records to be processed, and the number of records is an arbitrary number equal to or greater than 0. The processing target records R1 also include terminal identification information received before driving. Then, the process proceeds to S130.

[0070] In S130, the control unit 10 records all terminal identifiers recorded in the target record R1 in the terminal identifier list TL, without duplication. For example, if the target record R1 has five records (five lines) of the terminal identifier "1000", the control unit 10 records only one record of the terminal identifier "1000" in the terminal identifier list TL. Also, for example, if the target record R1 has 20 unique terminal identifiers, the control unit 10 records 20 pieces of data in the terminal identifier list TL. Then, the process proceeds to S140.

[0071] In S140, the control unit 10 determines whether or not the terminal identifier is recorded in the terminal identifier list TL. If the terminal identifier is recorded in the terminal identifier list TL (S140: Yes), the process proceeds to S150. If the terminal identifier is not recorded in the terminal identifier list TL (S140: No), the process proceeds to S200. Note that S140: No occurs when no terminal identifier is recorded in the target record R1, or when processing of all data recorded in the target record R1 has been completed.

[0072] In S150, the control unit 10 selects any one terminal identifier from the terminal identifier list TL as the terminal identifier X. Since unprocessed terminal identifiers are recorded in the terminal identifier list TL, any unprocessed terminal identifier is selected as the terminal identifier X. Then, the process proceeds to S160.

[0073] In S160, the control unit 10 identifies the record R1 to be processed in which the terminal identifier X is recorded in the terminal identifier field, calculates the number of records recorded consecutively in time, and records this in the reception count TR. If there are multiple intervals in which records are recorded consecutively in time, the control unit 10 uses the interval with the most consecutive records in time, and sets this number of records as the reception count TR. Then, the process proceeds to S170.

[0074] In S170, the control unit 10 determines whether the number of receptions TR is equal to or greater than a predetermined number of times P1 (predetermined value P1). The predetermined number of times P1 may be, for example, 20, but is not limited to this value. The predetermined number of times P1 may also be set according to the detection period T2. For example, it may be set so that the product of the detection period T2 and the predetermined number of times P1 corresponds to a time of several tens of seconds. If the number of receptions TR is equal to or greater than the predetermined number of times P1 (S170: Yes), the process proceeds to S180. If the number of receptions TR is less than the predetermined number of times P1 (S170: No), the process proceeds to S190.

[0075] In S180, the control unit 10 adds the terminal identifier X to the ride list PL, and then proceeds to S190.

[0076] In S190, the control unit 10 deletes the terminal identifier X from the terminal identifier list TL. That is, since the processed terminal identifier X is deleted from the terminal identifier list TL, only unprocessed terminal identifiers remain in the terminal identifier list TL. Then, the process returns to S140 and repeats.

[0077] In S200, the control unit 10 determines whether multiple terminal identifiers are recorded in the ride list PL. If multiple terminal identifiers are recorded (S200: Yes), the process proceeds to S210. If multiple terminal identifiers are not recorded (S200: No), the process ends. That is, if the number (type) of terminal identifiers received in the predetermined period Q1 is 0 or 1, the process ends. Note that before ending the process, the control unit 10 may associate the processing date and time with the number of terminal identifiers and store them in the storage unit 14.

[0078] In S210, the control unit 10 identifies the time when each terminal identifier recorded in the ride list PL was first detected and records it in the start time list SL. Specifically, the control unit 10 identifies the reception time of the record in the target record R1 where each terminal identifier is first recorded as the start time. The control unit 10 associates the terminal identifier with the start time and records them in the start time list SL.

[0079] For example, in the case of the data in FIG. 5, data such as "terminal identifier=1000: start time=2023 / 09 / 14 10:35:00, terminal identifier=2000: start time=2023 / 09 / 14 10:35:00" is recorded in the start time list SL (hereinafter also referred to as start time list SL-A).

[0080] 6, data such as "terminal identifier=1000: start time=2023 / 09 / 14 10:35:00, terminal identifier=2000: start time=2023 / 09 / 14 10:35:08" is recorded in the start time list SL (hereinafter also referred to as start time list SL-B). Then, the process proceeds to S220.

[0081] In S220, the control unit 10 refers to the start time list SL and groups the terminal identifiers. Specifically, terminal identifiers whose difference in start time is less than a predetermined time (threshold Tg) are grouped together. For example, the threshold Tg may be set to 1 second. In the start time list SL-A described above, the difference in start time is 0 seconds, so the two terminal identifiers are in the same group. Therefore, a group such as "Group 1 = (1000, 2000)" is formed.

[0082] On the other hand, in the start time list SL-B, the difference in start time is 8 seconds, so the two terminal identifiers are grouped into two groups. Therefore, two groups are formed, such as "Group 1 = (1000) and Group 2 = (2000)." Of course, there are cases where three or more terminal identifiers are in the same group. For example, if the maximum difference in start time of three or more terminal identifiers is equal to or less than the threshold value Tg, they are grouped into one group. Then, proceed to S230.

[0083] In S230, the control unit 10 calculates (counts) the number of groups and sets the number of groups as the number of passengers. Terminal identifiers for the same group are likely to be terminal identifiers of mobile terminals 5 carried by one user. Terminal identifiers for different groups are likely to be terminal identifiers of mobile terminals 5 carried by different users. Therefore, the number of groups is likely to indicate the number of passengers. Then, the process proceeds to S240.

[0084] In S240, the control unit 10 determines whether the number of passengers (number of groups) exceeds the passenger capacity C. If the number of passengers exceeds the passenger capacity C (S240: Yes), the process proceeds to S250. If the number of passengers is equal to or less than the passenger capacity C (S240: No), the process ends.

[0085] In S250, the control unit 10 records (stores) information indicating that the number of passengers exceeds the capacity in the storage unit 14. Specifically, when the control unit 10 detects an abnormal state in which the number of passengers in the vehicle 3 exceeds the capacity, the control unit 10 acquires the current date and time from the clock unit 13 and stores abnormality information including at least the detection date and time in the storage unit 14. Of course, the detection date and time may be stored in the storage unit 14 in association with the detected number of passengers (the calculated number of groups).

[0086] Furthermore, the control unit 10 may acquire the current location (latitude, longitude, etc.) from the location information identification unit 18, associate the detection date and time, the location information, the number of people, and the terminal identifier recorded in the passenger list PL, and store them in the storage unit 14 as an over-capacity information list (anomaly information list). Then, the process ends.

[0087] The control unit 10 may omit S240, proceed from S230 to S250, and store the detected number of passengers in the memory unit 14 regardless of whether the detected number of passengers exceeds the passenger capacity C. For example, the control unit 10 may store the detected date and time and the number of passengers in the memory unit 14 in association with each other.

[0088] Also, in S210, the time when each terminal identifier was first recorded in the processing target record R1 is specified, but this is not limited to this. For example, the control unit 10 may store the reception time, terminal identifier, and received signal strength in association with each other in the terminal identification information history table, and specify the first time when the received signal strength became equal to or greater than a predetermined value (e.g., -60 dBm). Furthermore, the control unit 10 may specify the first time when the received signal strength became equal to or greater than a predetermined value (e.g., -60 dBm) N or more consecutive times (e.g., three times).

[0089] The control unit 10 may perform the process of detecting the number of passengers in the vehicle 3 shown in the flowcharts of Figures 7 and 8 periodically, not just at the start of travel. If the control unit 10 determines that the number of passengers in the vehicle 3 exceeds the capacity of the vehicle 3, it may record the information in the storage unit 14 or display warning information on the display unit 15. For example, if the vehicle 3 is an electric kick scooter or a bicycle, there is a possibility, although not very high, that someone may jump on the vehicle 3 while it is traveling, so such processing is effective.

[0090] 9 is an example of warning information displayed on the display unit 15. For example, a message such as "The vehicle's passenger capacity has been exceeded. Please disembark immediately" may be displayed. The audio output unit 17 may also output a voice message or a warning sound for the warning information. The propulsion control unit 32 of the vehicle 3 may also forcibly stop the vehicle 3.

[0091] FIG. 10 is a diagram showing an example of the over-occupancy information list created in S250 of the flowcharts of FIGS. 7 and 8. As shown in this figure, the over-occupancy information list is data that associates the over-occupancy date and time (date and time when the over-occupancy occurred), the over-occupancy location (location where the over-occupancy occurred (latitude, longitude)), the number of occupants (number of detected people), and the terminal identifier (terminal identifier of the mobile terminal 5 of the user who was in the vehicle 3 when the capacity was exceeded). In the example shown in this figure, a maximum of N terminal identifiers (for example, N=10) can be recorded. Furthermore, each row represents one piece of over-occupancy information.

[0092] That is, when a new overcapacity occurs, new data (a new row) is added to the overcapacity information list. The overcapacity information list may record all overcapacity information that has occurred in the past, or may record overcapacity information that has occurred within a predetermined period (for example, the last three months). The control unit 10 may periodically delete data after the predetermined period has elapsed.

[0093] The control unit 10 may read out the over-occupancy information list at any timing and display it on the display unit 15. For example, the control unit 10 may display the over-occupancy information list on the display unit 15 in a table format as shown in FIG. 11. FIG. 11 is an example of a display of over-occupancy information showing the over-occupancy information list in a table format. The user of the vehicle 3 may operate the operation unit 16 to sort the information in ascending / descending order by an item specified by the user (over-occupancy date and time, over-occupancy location, or number of occupants). Although not shown in this figure, the terminal identifier detected when the capacity is exceeded may also be displayed.

[0094] The control unit 10 may display the information in the over-occupancy information list on a map using a map database stored in the memory unit 14 or a map database obtained from the Internet or the like via the communication unit 19. Fig. 12 is a diagram showing an example in which a map and over-occupancy information are superimposed and displayed on the display unit 15. As shown in this figure, points where over-occupancy has occurred in the past are indicated with a predetermined mark (here, a "square" mark), the number of occupants is displayed within the mark, and the date and time when the over-occupancy was detected is also displayed.

[0095] In addition, when the detection device 1 does not have a display unit 15, the control unit 10 may transmit the over-capacity information list to a mobile terminal 5 such as a smartphone carried by the user via the communication unit 19 or the short-range communication unit 11, and the mobile terminal 5 may display the list as shown in Fig. 12. The communication unit 19 may communicate with the mobile terminal 5 using long-distance communication such as a mobile phone line, or, like the short-range communication unit 11, may communicate with the mobile terminal 5 using short-range communication such as Bluetooth.

[0096] The over-capacity information list may also be recorded on a removable storage medium such as a memory card, and a manager of the vehicle 3, such as a sharing service provider, may remove the storage medium and obtain the over-capacity information list. The vehicle 3 may also be connected to an external device via a wired or wireless connection, and the over-capacity information list may be transmitted to the external device (for example, a server or terminal device managed by the sharing service provider).

[0097] When renting out a vehicle 3, the sharing service provider may require the user to enter the terminal identifier of the user's mobile terminal 5, and if the terminal identifier of the user's mobile terminal 5 is frequently recorded in the over-capacity information list, the provider may take measures such as raising the fee or prohibiting the rental of the vehicle 3. Furthermore, the insurance company of the vehicle 3 may raise the user's insurance premium if the terminal identifier of the user's mobile terminal 5 is frequently recorded in the over-capacity information list, or conversely, may lower the user's insurance premium if the recording frequency is infrequent. This can raise users' awareness of safe driving.

[0098] According to this embodiment, the detection device 1 receives radio waves transmitted from the mobile terminals 5, detects terminal identifiers that are detected consecutively a predetermined number of times or more within a predetermined period (continuously for a predetermined period of time or more), and groups terminal identifiers that are presumed to be carried by the same person based on the start time of detection of each identifier, calculates the number of groups, and sets this as the number of passengers. This makes it possible to accurately detect the number of passengers in the vehicle 3 with a relatively simple configuration. For example, even if one person is carrying multiple mobile terminals 5, it is possible to accurately detect the number of passengers in the vehicle 3.

[0099] In addition, the influence of radio waves transmitted from mobile terminals 5 carried by pedestrians around the vehicle 3 and from mobile terminals 5 in other vehicles 3 can be reduced, making it possible to accurately detect the number of passengers using a relatively simple system.

[0100] Furthermore, when an abnormal state in which the number of passengers on board exceeds the capacity of vehicle 3 is detected, it is possible to issue an appropriate warning and stop vehicle 3. This makes it possible to prevent accidents and other incidents caused by the number of passengers on board exceeding the capacity of vehicle 3.

[0101] As described above, according to the detection device 1 of this embodiment, the number of people present around the detection device 1 can be detected with high accuracy using a relatively simple system.

[0102] <Modification of Example 1> In the first embodiment, the number of passengers in the vehicle 3 is detected by the detection device 1 mounted on the vehicle 3. In this modification, a detachable detection device 1 is attached to the vehicle 3 to detect the number of passengers.

[0103] The detection device 1 described in this modification is specifically a smartphone, a tablet terminal, or a navigation terminal such as a PND (Portable Navigation Device) that can be retrofitted to the vehicle 3. It is preferable to provide a cradle or attachment unit for installing the detection device 1 on the vehicle 3 so that the detection device 1 can be easily attached and detached. The configuration of the detection device 1 in this modification is the same as the configuration of the detection device 1 in Example 1 shown in FIG. 4.

[0104] According to this modification, since the detection device 1 can be easily attached / detached to the vehicle 3, it is possible to easily add a detection function to a vehicle 3 that does not have a function for detecting the number of passengers. Furthermore, when the detection function is not required, the detection device 1 can be easily detached. Furthermore, a smartphone or tablet device owned by the user can be used as the detection device 1. Therefore, it is particularly easy to apply to vehicles 3 provided by sharing service providers and rental companies. Since the detection device 1 can be easily detached after using the vehicle 3, the risk of failure of the detection device 1 can be reduced even when the vehicle 3 is stored (parked) outdoors. Furthermore, if the detection device 1 breaks down due to aging or the like, it can be easily replaced.

[0105] <Example 2> In the first embodiment, when the vehicle 3 starts traveling, the terminal identification information history table in the memory unit 14 is referenced to determine the number of people riding in the vehicle 3. In the present embodiment, when a user gets off the vehicle 3, the terminal identification information history table is referenced to determine the number of people riding in the vehicle 3. The configuration of the detection device 1 in this embodiment is the same as the configuration of the detection device 1 in the first embodiment shown in FIG. 4.

[0106] In this embodiment, the control unit 10 also records in the terminal identification information history table the terminal identification information received after the vehicle 3 has been driven (stopped). For example, the control unit 10 may always record in the terminal identification information history table during an operable period (a period during which power is supplied).

[0107] The control unit 10 may record all received terminal identification information in the terminal identification information history table, or may record only terminal identification information whose received signal strength satisfies a predetermined condition (for example, -65 dBm or more). For example, the condition for the received signal strength to be recorded in the terminal identification information history table may be set so that information transmitted from a mobile terminal 5 within a predetermined distance from the vehicle 3 (for example, within 2 m) is recorded, and information transmitted from a mobile terminal 5 farther away than the predetermined distance is not recorded.

[0108] In addition, the conditions for the received signal strength to be recorded in the terminal identification information history table may be set so that information transmitted from a mobile terminal 5 inside (on) the vehicle 3 is recorded, but information transmitted from a mobile terminal 5 outside the vehicle is not recorded.

[0109] 13 and 14 are examples of a terminal identification information history table in this embodiment. The table in Fig. 13 shows a state in which one user in a vehicle 3 carries two mobile terminals 5. This figure also shows data up to the point in time when the terminal identifier was last recorded in the terminal identification information history table.

[0110] As shown in this figure, two mobile terminals 5 with terminal identifiers "1000" and "2000" are recorded in the table, but both mobile terminals 5 are carried by the same user. Therefore, the reception times of the two terminal identifiers are consistently the same, and the time at which recording of the two terminal identifiers ended is also the same (2023 / 09 / 14 10:35:09). In this way, when one user carries multiple mobile terminals 5, it is highly likely that the short-range communication unit 11 will be unable to receive signals from those devices at the same time, or the received signal strength will no longer satisfy a predetermined standard, and therefore recording of multiple terminal identifiers will end at the same time.

[0111] On the other hand, FIG. 14 is an example of a terminal identification information history table in the case where two users riding in a vehicle 3 each carry one mobile terminal 5. As shown in this figure, one user's mobile terminal 5 (terminal identifier "2000") finished recording at "2023 / 09 / 14 10:35:04", and then another user's mobile terminal 5 (terminal identifier "1000") finished recording at "2023 / 09 / 14 10:35:14". In other words, there is a 10-second difference between the recording end times of the two terminal identifiers. When two users get off the vehicle 3, the timing at which they get off and move away from the vehicle 3 often differs from person to person, so it is highly likely that the recording end times will differ depending on the terminal identifier.

[0112] Therefore, when multiple terminal identifiers are detected consecutively in the terminal identification information history table, the control unit 10 groups the terminal identifiers by comparing the end times (last times) at which the terminal identifiers were detected. Specifically, similar to the first embodiment, the control unit 10 groups terminal identifiers whose difference in end time is equal to or less than the threshold value Tg into the same group. The control unit 10 then counts the number of groups and determines whether the number of groups exceeds the capacity C. For example, the threshold value Tg may be set to 1 second.

[0113] If the threshold value Tg is set to 1 second, the number of groups will be 1 in the example of Fig. 13, and 2 in the example of Fig. 14. The control unit 10 stores such a determination result in the memory unit 14 in association with the date and time. Note that when the user performs an operation to turn off the power of the vehicle 3, it is desirable that the power is not actually turned off immediately, but that the control unit 10, short-range communication unit 11, memory unit 14, etc. continue to operate for a predetermined time (for example, 3 minutes), and continue recording in the terminal identification information history table.

[0114] In addition, the next time the user uses vehicle 3, a warning message may be displayed on the display unit 15 of vehicle 3 stating, "Last time, we observed passengers exceeding capacity. Please refrain from exceeding capacity as this is dangerous."

[0115] The processing in this embodiment has the same flow as the flowcharts in FIGS. 7 and 8, but differs in the following respects.

[0116] In S100A corresponding to S100, the control unit 10 determines whether the vehicle 3 has stopped or whether an operation to turn off the power of the vehicle 3 has been performed. If the vehicle 3 has stopped or an operation to turn off the power of the vehicle 3 has been performed (S100A: Yes), the process proceeds to S110 after a predetermined time (for example, 30 seconds) has elapsed.

[0117] In S210A, which corresponds to S210, the control unit 10 identifies the time when each terminal identifier recorded in the ride list PL was last detected and records it in the end time list EL. Specifically, the control unit 10 identifies the reception time of the record in the target record R1 in which each terminal identifier was last recorded as the end time. Alternatively, the control unit 10 may identify the last time when the signal strength exceeded a predetermined value as the end time. The control unit 10 associates the terminal identifier with the end time and records them in the end time list EL.

[0118] In S220A corresponding to S220, the control unit 10 refers to the end time list EL and groups the terminal identifiers. Specifically, the control unit 10 groups the terminal identifiers whose difference in end time is equal to or less than the threshold value Tg.

[0119] Furthermore, the control unit 10 may execute the above-described processing periodically, not just when the vehicle 3 is stopped or when the power is turned off, and if it determines that the number of people on board the vehicle 3 exceeds the capacity of the vehicle 3, it may record that information in the storage unit 14 or display warning information on the display unit 15. For example, if the vehicle 3 is an electric kick scooter or bicycle, there is a possibility, although not very high, that someone other than the driver may jump out of the moving vehicle 3, so such processing is also effective.

[0120] According to this embodiment, the detection device 1 compares the end times of detection of mobile devices 5 around the vehicle 3, groups the device identifiers of the mobile devices 5 that are presumed to be carried by the same person, calculates the number of groups, and sets this as the number of passengers. This enables the detection device 1 to accurately determine the number of passengers in the vehicle 3.

[0121] Example 3 In this embodiment, the detection device 1 detects the number of passengers in the vehicle 3 based on temporal changes in the received signal strength (RSSI: Received Signal Strength Indicator) of the terminal identification information received by the short-range communication unit 11 (receiving unit 101). The received signal strength is also called signal strength. The configuration of the detection device 1 in this embodiment is the same as the configuration of the detection device 1 in the first embodiment shown in FIG.

[0122] The control unit 10 calculates (creates) time-series data based on the signal strength in each cycle. More specifically, the control unit 10 calculates (creates) at least one of time-series data of the signal strength in each cycle and time-series data of the temporal difference value of the signal strength in each cycle. The control unit 10 groups the device identifiers based on the calculated time-series data. More specifically, the control unit 10 calculates the similarity between the calculated time-series data for each combination of multiple device identifiers, and groups the device identifiers by grouping multiple device identifiers whose similarity meets a predetermined criterion. The control unit 10 may determine that the predetermined criterion is met, for example, if the similarity is equal to or greater than a predetermined value.

[0123] In this embodiment, similarly to the first embodiment, the control unit 10 also records in the terminal identification information history table the terminal identification information received before the vehicle 3 starts traveling. In the following description, the detection period T2 is set to 200 milliseconds, but it is not limited to this value.

[0124] The terminal identification information history table in this embodiment stores the reception time, terminal identifier, and received signal strength in association with each other. As described above, the control unit 10 may set the condition for the received signal strength to be recorded in the terminal identification information history table so as to record only information transmitted from a mobile terminal 5 within a predetermined distance from the vehicle 3 or a mobile terminal 5 inside (on) the vehicle 3.

[0125] FIG. 15 is a diagram (graph) showing an example of changes in received signal strength before and after vehicle 3 starts moving. The horizontal axis of this diagram represents time, and the vertical axis represents received signal strength, with the received signal strength increasing (stronger) as one moves higher on the graph. The unit of received signal strength may be dBm. This diagram shows changes in received signal strength when two users, each carrying two mobile terminals 5, board vehicle 3.

[0126] For example, a situation may arise in which user A, who will be the driver, gets into vehicle 3 first with mobile terminals 5 with terminal identifiers "1000" and "2000" in his pocket or bag, and another user B gets into vehicle 3 later with mobile terminals 5 with terminal identifiers "3000" and "4000" in his pocket or bag. When two people get into vehicle 3 such as an electric kick scooter or bicycle, it is unlikely that they will get in at the same time, and it is common for the driver to get in first and then the other user to get in later.

[0127] As shown in Fig. 3, since the detection device 1 (short-range communication unit 11) is installed at the front of the vehicle 3 (near the handlebars in the case of an electric kick scooter), the received signal strength of the terminal identifiers "1000" and "2000" held by user A, who will be the driver, increases first. Then, the received signal strength of the terminal identifiers "3000" and "4000" held by user B increases later.

[0128] Furthermore, at time Ta, user A completes boarding and his position (posture) becomes almost constant, so the received signal strengths of terminal identifiers "1000" and "2000" become almost constant from time Ta onwards. Similarly, at time Tb, user B completes boarding and his position (posture) becomes almost constant, so the received signal strengths of terminal identifiers "3000" and "4000" become almost constant from time Tb onwards.

[0129] As shown in the figure, the temporal changes in the received signal strength of portable terminals 5 carried by the same person have a common (similar) pattern, whereas the temporal changes in the received signal strength of portable terminals 5 carried by different people have different patterns. In this embodiment, the number of passengers is detected based on such temporal changes in the received signal strength.

[0130] The flow of processing by the detection device 1 in this embodiment will be described with reference to Fig. 16. Fig. 16 is a flowchart showing the flow of processing by the detection device 1.

[0131] S300 is the same as S100 in Fig. 7. That is, the control unit 10 determines whether or not the vehicle 3 has started traveling.

[0132] S310 is the same as S120 in Fig. 7. That is, the control unit 10 refers to the terminal identification information history table in the storage unit 14, and extracts all records whose reception times are within a predetermined period Q1 (for example, 3 minutes) from the current time as records to be processed R1.

[0133] In S320, the control unit 10 creates signal strength time-series data indicating the change over time in the received signal strength for each terminal identifier for the processing target record R1, and stores the data in the storage unit 14.

[0134] An example of signal strength time series data is shown in Figure 17. Figure 17 is an example of signal strength time series data corresponding to the graph in Figure 15. The received signal strength for each detection period T2 is recorded in association with each terminal identifier included in the processing target record R1. In the example shown in this figure, four terminal identifiers, "1000," "2000," "3000," and "4000," are included in the processing target record R1, and the received signal strength for each is recorded in dBm every 200 milliseconds.

[0135] In the following explanation, it is assumed that the signal strength time series data has Tn pieces of data (t=1 to Tn) recorded. If there is data in which radio waves are not detected during part of t=1 to Tn, the received signal strength can be set to a predetermined value (for example, a very small value such as -100 dBm) and the following processing can be performed.

[0136] Return to FIG. 16. In S330, the control unit 10 calculates an index indicating the similarity (similarity degree) between terminal identifiers for the signal strength time series data. In the following description, the received signal strength at time t for terminal identifier i is denoted as E[i][t], the received signal strength at time t for terminal identifier j is denoted as E[j][t], and the index indicating the similarity between terminal identifier i and terminal identifier j is denoted as D[i][j]. For example, when there are four terminal identifiers, under the conditions of i, j = 1 to 4 and i < j, the combination of terminal identifier i and terminal identifier j is changed, and the index D[i][j] is calculated.

[0137] The control unit 10 calculates an index D[i][j] indicating the similarity between the time series data based on the signal strength corresponding to terminal identifier i and the time series data based on the signal strength corresponding to terminal identifier j using any one of formulas (1) to (6). Hereinafter, each of the indexes D[i][j] calculated by formulas (1) to (6) is denoted as index D1[i][j] (index D1) to D6[i][j] (index D6). When there is no need to distinguish each of index D1[i][j] to D6[i][j], these are collectively referred to simply as "index D[i][j]". Index D1 to index D6 are all indexes indicating the similarity between time series data based on (related to) signal strength.

[0138]

Equation

[0139]

Equation

[0140] Equation (1) and equation (2) represent the distance between the signal strength time-series data of terminal identifier i and the signal strength time-series data of terminal identifier j. Equation (1) represents their Euclidean distance, and equation (2) represents their Manhattan distance. In equations (1) and (2), indices D1[i][j] and D2[i][j] take values ​​greater than or equal to 0, and the smaller the index value, the higher the similarity (degree of similarity) between terminal identifier i and terminal identifier j. In other words, the closer the values ​​of indices D1[i][j] and D2[i][j] are to 0, the higher the similarity (degree of similarity) between terminal identifier i and terminal identifier j. In this embodiment, such distances are also included in the similarity. In other words, the relationship between the level of similarity and the magnitude of the index value may be arbitrary.

[0141]

number

[0142] In equation (3), M[i] is the average value of the received signal strength of terminal identifier i, and M[j] is the average value of the received signal strength of terminal identifier i. Equation (3) is the correlation coefficient between the signal strength time-series data of terminal identifier i and the signal strength time-series data of terminal identifier j, and index D3[i][j] takes a value in the range from -1 to +1. The larger the value of index D3[i][j] (closer to +1), the higher the similarity (degree of similarity) between terminal identifier i and terminal identifier j, and the smaller the value of index D3[i][j] (closer to -1), the lower the similarity (degree of similarity).

[0143]

number

[0144]

number

[0145] Equations (4) and (5) represent the distance between the time series data of the temporal difference value of the received signal strength of terminal identifier i and the time series data of the temporal difference value of the received signal strength of terminal identifier j. In other words, the distance between two terminal identifiers is calculated using the difference value between the received signal strength at time t (point in time t) and the received signal strength at time t-1 of the previous period. Equation (4) represents their Euclidean distance, and Equation (5) represents their Manhattan distance. In equations (4) and (5), the indices D4[i][j] and D5[i][j] take values ​​greater than or equal to 0, and the smaller the index value, the higher the similarity (degree of similarity) between terminal identifier i and terminal identifier j.

[0146] In equations (4) and (5), even if the difference (level difference) between the received signal strength of terminal identifier i and the received signal strength of terminal identifier j is large, if the patterns of increase and decrease over time are similar, the index value will be small. Therefore, this is suitable for cases where you want to calculate an index that places emphasis on the pattern of increase and decrease in received signal strength over time rather than the magnitude of the received signal strength itself.

[0147]

number

[0148] Equation (6) is the cosine similarity between the time series data of the temporal difference value of the received signal strength of terminal identifier i and the time series data of the temporal difference value of the received signal strength of terminal identifier j. In equation (6), index D6[i][j] takes a value in the range of -1 to +1. The larger the value of index D6[i][j] (closer to +1), the higher the similarity (degree of similarity) between terminal identifier i and terminal identifier j, and the smaller the value of index D6[i][j] (closer to -1), the lower the similarity (degree of similarity).

[0149] For example, when the signal strength time series data contains four terminal identifiers, i, j = 1 to 4, and i < j. Therefore, in S330, six indicators D[1][2], D[1][3], D[1][4], D[2][3], D[2][4], and D[3][4] will be calculated. Note that the control unit 10 may calculate a plurality of indicators among the indicators D1 to D6, and calculate a comprehensive indicator based on them. For example, the indicator D1 and the indicator D2 may be calculated, and their sum may be used as the comprehensive indicator D (D = D1 + D2). Also, for example, the indicator D1 and the indicator D4 may be calculated, and their sum may be used as the comprehensive indicator D (D = D1 + D4). That is, the control unit 10 only needs to calculate at least one of the indicators D1 to D6.

[0150] In S340, the control unit 10 groups terminal identifiers with high similarity in the signal strength time series data into the same group to form a group. Specifically, the control unit 10 groups a plurality of terminal identifiers whose indicators (similarity degrees) meet a predetermined criterion into the same group.

[0151] In S330, when an indicator is calculated using any of the formulas (1), (2), (4), and (5), the smaller the value of the indicator, the higher the similarity. Therefore, the control unit 10 uses the condition that "the indicator is less than or equal to a predetermined value" as a predetermined criterion, and groups the terminal identifiers that meet this condition into the same group.

[0152] For example, when the indicator is calculated using the formula (2), the control unit 10 sets the absolute value of the difference in signal strength that can be regarded as similar at each time point as ΔE (for example, ΔE = 4 dBm), calculates the threshold Dg as Dg = ΔE × Tn, and may group the identifiers whose indicator D2[i][j] is less than or equal to the threshold Dg into the same group. Even when the control unit 10 calculates an indicator using other mathematical formulas, the threshold Dg may be set in the same way, and the identifiers whose indicator D[i][j] is less than or equal to the threshold Dg may be grouped into the same group.

[0153] Also, when calculating the index using Equation (3) or Equation (6), the index ranges from -1 to +1. Since the higher the value of the index, the higher the similarity, the control unit 10 uses the condition that "the index is greater than or equal to a predetermined threshold Dh" as a predetermined criterion, and groups the terminal identifiers that meet this condition into the same group. For example, the control unit 10 may set Dh = 0.6 and group the terminal identifiers with an index of 0.6 or higher into one group.

[0154] For example, when calculating the index D1[i][j] (i, j = 1 to 4, i < j) using Equation (1) for the signal strength time series data shown in FIGS. 15 and 17, the values are approximately as follows. D1[1][2]=11.1, D1[1][3]=61.7, D1[1][4]=71.2, D1[2][3]=51.9, D1[2][4]=61.1, D1[3][4]=10.7.

[0155] Here, assuming the threshold Dg = 20, among these, D1[1][2] and D1[3][4] are less than or equal to the threshold Dg and meet the predetermined criterion. Therefore, the combination of i = 1 (terminal identifier "1000") and j = 2 (terminal identifier "2000") belongs to the same group, and the combination of i = 3 (terminal identifier "3000") and j = 4 (terminal identifier "4000") belongs to the same group. On the other hand, the remaining indices do not meet the predetermined criterion and are not integrated into the group. That is, in the case of the example shown in FIGS. 15 and 17, two groups are formed from the four terminal identifiers.

[0156] Note that when the index does not meet the predetermined criterion, each terminal identifier constituting the index forms an independent group. For example, if there are six terminal identifiers in the signal strength time series data, D[1][2] and D[3][4] meet the predetermined criterion, and D[5][6] does not meet the predetermined criterion, then i = 5 and 6 will be in separate groups, resulting in the formation of four groups.

[0157] Also, three or more terminal identifiers may be grouped together. For example, if D[1][2] and D[1][3] meet a predetermined criterion, or if D[1][2] and D[2][3] meet a predetermined criterion, i=1 to 3 may be grouped together.

[0158] In S350, the control unit 10 calculates (counts) the number of groups formed in S340, and sets the number of groups as the number of passengers in the vehicle 3. In the examples shown in Fig. 15 and Fig. 17, the number of groups is determined to be 2, and the number of passengers is also determined to be 2.

[0159] S360 is the same as S240 in Fig. 8. S370 is the same as S250 in Fig. 8. As in the description of the first embodiment, S360 may be omitted, and the process may proceed from S350 to S370, and the detected number of passengers may be stored in the memory unit 14 regardless of whether the detected number of passengers exceeds the capacity C.

[0160] In this embodiment, the control unit 10 detects the number of passengers in the vehicle 3 by grouping terminal identifiers that are presumed to be carried by the same person based on temporal changes in the received signal strength of the terminal identification information received by the short-range communication unit 11. Therefore, the detection device 1 can accurately detect the number of passengers in the vehicle 3 with a relatively simple configuration. The detection device 1 can accurately detect the number of passengers in the vehicle 3 even when, for example, one person is carrying multiple mobile terminals 5.

[0161] As in the second embodiment, it is also possible to perform the same processing as in this embodiment when the vehicle 3 is stopped or when an operation to turn off the power of the vehicle 3 is performed. That is, the control unit 10 may create signal strength time-series data around the time when the vehicle 3 is stopped or when an operation to turn off the power of the vehicle 3 is performed, and perform the same processing as in S330 to S370 on the signal strength time-series data to group the terminal identifiers.

[0162] <Modification of Example 3> In the third embodiment, groups are formed based on time-series data of received signal strength or time-series data of temporal difference values ​​of signal strength, but the present invention is not limited to this. In this modified example, the distance between the vehicle 3 and the mobile terminal 5 is calculated (estimated) based on the received signal strength, and groups are formed based on the time-series data of the distance. Because the distance is calculated based on the signal strength, such time-series data of the distance can also be considered as one type of time-series data based on the signal strength. In this modified example, transmission power information is included in the terminal identification information received by the short-range communication unit 11, and the transmission power information (TX_POWER) included in the terminal identification information and the received signal strength indicator (RSSI) information when the terminal identification information is received by the short-range communication unit 11 of the vehicle 3 are recorded together in the terminal identification information history table.

[0163] 16, the control unit 10 creates distance time-series data indicating the change over time in the distance between the vehicle 3 (short-range communication unit 11) and the mobile terminal 5 for each terminal identifier for the record R1 to be processed, and stores the data in the storage unit 14. Specifically, the control unit 10 calculates the distance L[i][t] between the vehicle 3 and the mobile terminal 5 based on the received signal strength and the transmission output according to the following equation (7).

[0164] Here, Tx[i][t] is the transmission power of terminal identifier i at time t, E[i][t] is the received signal strength of terminal identifier i at time t, and L[i][t] is the distance of terminal identifier i at time t. Also, the "^" symbol indicates an exponentiation operation, and the "*" symbol indicates a multiplication operation.

[0165]

number

[0166] The control unit 10 calculates L[i][t] for each terminal identifier and each time included in the record R1 to be processed, and creates a distance time-series table.

[0167] 18 is a diagram showing an example of distance time-series data. In the example shown in this figure, four terminal identifiers, "1000," "2000," "3000," and "4000," are included in the record R1 to be processed, and the distance between the mobile terminal 5 corresponding to each terminal identifier and the vehicle 3 is recorded in meters every 200 milliseconds. In this modification, the same processes as S330 to S370 are performed on such distance time-series data to detect the number of passengers in the vehicle 3.

[0168] According to this modification, the distance between the vehicle 3 and the mobile terminal 5 is estimated, and terminal identifiers with similar change patterns in the distance are grouped together, so that the detection device 1 can detect the number of passengers more accurately.

[0169] Example 4 In Examples 1 to 3, the terminal identifiers were grouped based on temporal changes in the signal received by the short-range communication unit 11, and the number of passengers was detected based on the number of groups. In this example, the number of groups is determined more accurately by combining with any of the processes of Examples 1 to 3. In this example, more detailed information about the mobile terminal 5 is obtained from the terminal identifiers in the received terminal identification information (for example, Bluetooth advertising packets). The configuration of the detection device 1 in this example is the same as the configuration of the detection device 1 in Example 1 shown in FIG. 4.

[0170] In this embodiment, the number of groups is calculated more accurately by using information on devices (hereinafter referred to as "specific devices") that are unlikely to be carried by one person in multiples. The storage unit 14 in this embodiment stores specific device information that indicates specific devices. More specifically, the storage unit 14 stores, as the specific device information, at least one of category information that indicates the category of the specific device and model name information that indicates the model name of the specific device. In addition, the short-range communication unit 11 further receives detailed information that can determine whether the mobile terminal 5 corresponding to the terminal identifier is a specific device. If the mobile terminal 5 is a specific device, the detailed information includes information that matches at least one of the category information and model name information in the storage unit 14.

[0171] The control unit 10 identifies the terminal identifiers corresponding to the specific devices based on the received detailed information and the stored specific device information, and adjusts the parameters used for grouping so that the number of groups is equal to or greater than the number of identified terminal identifiers. This embodiment will be described in detail below.

[0172] 19 is an example of a sequence diagram showing processing between the detection device 1 and multiple mobile terminals 5. In this diagram, two mobile terminals 5A and 5B are shown as the multiple mobile terminals 5. In addition, in this diagram, the terminal identifiers of the mobile terminals 5A and 5B are terminal identifiers a and b, respectively.

[0173] As explained in the first embodiment, the mobile terminal 5 transmits terminal identification information including at least a terminal identifier at a predetermined cycle. In the example shown in the figure, the terminal identification information further includes transmission output information. In the example shown in the figure, the mobile terminals 5A and 5B transmit the terminal identification information at a predetermined cycle, and the detection device 1 receives the terminal identification information via the short-range communication unit 11.

[0174] When acquiring detailed information about the mobile terminal 5A, the control unit 10 transmits a request notification for detailed information (for example, a Bluetooth SCAN_REQ command) to the mobile terminal 5A. The request notification for detailed information includes the terminal identifier a of the destination (target) mobile terminal 5A. When the mobile terminal 5A receives the request notification for detailed information, it transmits a response notification (for example, a Bluetooth SCAN_RSP command) of the detailed information of the mobile terminal 5A to the detection device 1. The detailed information transmitted by the mobile terminal 5A includes information that can determine whether the mobile terminal 5A is a specific device. Specifically, the detailed information includes at least one of the category of the mobile terminal 5A (for example, smartphone, tablet terminal, PC, smart watch, earphones, etc.) and the model name of the mobile terminal 5A. The control unit 10 can determine whether the mobile terminal 5A is a specific device by comparing the received detailed information with the specific device information in the storage unit 14.

[0175] In this embodiment, at least one of a category list (category information) and a model name list (model name information) is stored in the memory unit 14. The category list indicates categories of portable terminals 5 that are unlikely to be carried by a single user of the vehicle 3. The model name list indicates model names of portable terminals 5 that are unlikely to be carried by a single user of the vehicle 3. The category list is an example of the above-mentioned category information. The model name list is an example of the above-mentioned model name information. The control unit 10 refers to at least one of the category list and the model name list, and calculates the number of portable terminals 5 that fall into that category among the surrounding portable terminals 5.

[0176] FIG. 20 is a diagram showing an example of a category list. In the example shown in this figure, "large tablet terminals," "personal computers," and "smart watches" are registered in the category list, but of course, the category list is not limited to these. Since it is difficult to put a "large tablet terminal" or a "personal computer" in a user's pocket, it is unlikely that a single user of vehicle 3 will own more than one of them. This possibility is particularly low for small vehicles such as electric kick scooters and bicycles. It is also unlikely that a single user will own more than one "smart watch."

[0177] FIG. 21 is a diagram showing an example of a model name list. In the example shown in this figure, model names and model numbers such as "tablet terminal," "personal computer," and "smart watch" are registered. The model name may also include a manufacturer name and a category name. In this embodiment, if the detailed information transmitted by the mobile terminal 5 includes a model name (including cases where both the model name and the category are included), it is assumed that a model name list is stored in the storage unit 14, and the control unit 10 refers to the model name list. Furthermore, if the detailed information transmitted by the mobile terminal 5 does not include a model name (including cases where only the category is included), it is assumed that a category list is stored in the storage unit 14, and the control unit 10 refers to the category list.

[0178] The category list and the model name list may change over time depending on the popularity of mobile devices, etc. For example, if wearable devices such as smart glasses become more popular in the future, they may be included as mobile devices to be detected.

[0179] First, a description will be given of an example in which this embodiment is combined with embodiment 1. In this embodiment, it is assumed that data is recorded in the terminal identification information history table every 200 milliseconds, for example.

[0180] The processing of the detection device 1 according to this embodiment will be described with reference to FIG. 22. FIG. 22 is a flowchart showing the processing flow of the detection device 1 in this embodiment. In this embodiment, the detection device 1 executes S180 of the flowchart shown in FIGS. 7 and 8 in the first embodiment, and then executes the processing of the flowchart shown in FIG. 22. That is, if S170: Yes, the process proceeds to S180, and from S180, the process proceeds to S400 in FIG. 22. Note that if S170: No, the process proceeds to S190, and the processing of the flowchart in FIG. 22 is not executed.

[0181] In S400, the control unit 10 transmits a request for detailed information to the mobile terminal with the terminal identifier X.

[0182] In S410, the control unit 10 determines whether or not detailed information has been received from the mobile terminal with the terminal identifier X. If detailed information has been received from the mobile terminal with the terminal identifier X (S410: Yes), the process proceeds to S420. If detailed information has not been received from the mobile terminal with the terminal identifier X (S410: No), the process returns to S410 and repeats the process.

[0183] In S420, the control unit 10 determines whether the detailed information received from the mobile terminal with terminal identifier X corresponds to the category list or model name list of the storage unit 14. In other words, it determines whether the detailed information of the terminal identifier X matches the specific device information. If it corresponds to the category list or model name list of the storage unit 14 (S420: Yes), proceed to S430. If it does not correspond to the category list or model name list of the storage unit 14 (S420: No), end the processing here and proceed to S190 in the flowchart of FIG. 7.

[0184] At S430, the control unit 10 adds the terminal identifier X to the specific device list. That is, if the portable terminal with the terminal identifier X corresponds to a specific device, it is registered in the specific device list. Therefore, the specific device list is a collection of terminal identifiers of portable terminals that are unlikely to be owned by a single user of the vehicle 3. From S430, the process proceeds to S190 in the flowchart of FIG. 7.

[0185] In this embodiment, after executing S210 in Fig. 8, the process proceeds to S212 (not shown). In S212, the control unit 10 calculates (counts) the number of terminal identifiers (number of specific devices) registered in the specific device list.

[0186] The specific device list has zero or more terminal identifiers registered. In other words, there are cases where a terminal identifier is registered in the specific device list, and cases where no terminal identifier is registered at all. In other words, the user of the vehicle 3 may or may not have a specific device, but if a specific device is detected, it is highly likely that there are at least as many occupants as the number of specific devices. In this embodiment, grouping is performed based on this knowledge. From S212, the process proceeds to S220A, which corresponds to S220 in FIG. 8.

[0187] In S220A, the control unit 10 groups the terminal identifiers based on the start time list SL and the number of specific devices. Specifically, the control unit 10 sets a parameter (here, threshold value Tg) used in grouping within a predetermined range so that the number of groups is equal to or greater than the number of specific devices. For example, if the predetermined range is equal to or greater than 1 second and equal to or less than 2 seconds, and the number of specific devices is 2, the control unit 10 first sets the upper limit of the predetermined range (2 seconds) as the threshold value Tg, and performs grouping. If the number of groups is equal to or greater than the number of specific devices (here, 2), the process proceeds to S230 in FIG. 8.

[0188] If the number of groups is less than the specified devices, the control unit 10 sets the threshold Tg within a predetermined range (for example, 1.5 seconds) and performs grouping again. The control unit 10 repeats this process to perform grouping. If the threshold Tg reaches the lower limit of the predetermined range (1 second), the control unit 10 adopts the group created based on the threshold Tg and proceeds to S230. In other words, if the number of groups does not become equal to or greater than the specified number of devices even when the parameters are set within the predetermined range, the control unit 10 sets the parameters to predetermined values ​​and performs grouping. The process from S230 onwards is the same as in the first embodiment.

[0189] Next, an example in which this embodiment is combined with embodiment 3 will be described. Fig. 23 is a flowchart showing the flow of processing in the detection device 1. S300 to S320 are the same as S300 to S320 in Fig. 16. After S320 is executed, the process proceeds to S322.

[0190] In S322, the control unit 10 executes the same process as that shown in the flowchart of FIG. 22 for each terminal identifier included in the target record R1 to create a specific device list.

[0191] In S324, the control unit 10 calculates (counts) the number of terminal identifiers (number of specific devices) registered in the specific device list. S330 is the same as S330 in FIG.

[0192] S340A corresponds to S340 in Fig. 16. In S340A, the control unit 10 forms groups by grouping terminal identifiers that are highly similar into the same group, taking into account the number of specific devices. Specifically, the parameter used for grouping (here, threshold value Dg) is set within a predetermined range so that the number of groups is equal to or greater than the number of specific devices.

[0193] For example, if the range of threshold value Dg is 10 to 30 and the number of specific devices is 2, the control unit 10 first sets the upper limit of the predetermined range (30) as threshold value Dg and performs grouping. If the number of groups is equal to or greater than the number of specific devices (here, 2), the process proceeds to S350. If the number of groups is less than the number of specific devices, threshold value Dg is set within the predetermined range (for example, 20) and grouping is performed again.

[0194] This process is repeated to form groups, but if the threshold value Dg reaches the lower limit (10) of the predetermined range, the group created based on the threshold value Dg is adopted, and the process proceeds to S350. In other words, if the number of groups does not exceed the specified number of devices even when the parameters are set within the predetermined range, the parameters are set to predetermined values ​​and grouping is performed. The process from S350 onwards is the same as that shown in FIG.

[0195] According to this embodiment, the detection device 1 extracts specific devices that are unlikely to be carried (possessed) by a single user of the vehicle 3 from among the mobile terminals 5 present in the vicinity, and adjusts the parameters used for grouping so that the number of groups is equal to or greater than the number of specific devices. This enables the detection device 1 to detect the number of people in the vehicle 3 with higher accuracy.

[0196] <Example 5> When there are other vehicles or pedestrians around a traveling vehicle 3 that are moving in the same direction and at the same speed as the vehicle 3, there is a possibility that terminal identification information from mobile terminals 5 other than those of the occupants of the vehicle 3 will be continuously detected. For example, when a person and a friend are riding in multiple vehicles and heading to the same destination at the same time, there is a possibility that terminal identifiers transmitted from other vehicles will be continuously received. In this embodiment, the distance between the mobile terminal 5 and the vehicle 3 is calculated for the terminal identifier received while the vehicle 3 is traveling, thereby determining whether or not the terminal identifier is from a mobile terminal 5 carried by an occupant of the vehicle 3. The configuration of the detection device 1 in this embodiment is the same as the configuration of the detection device 1 in Example 1 shown in FIG. 4.

[0197] In this embodiment, the terminal identification information includes transmission power information, and the transmission power information (TX_POWER) included in the terminal identification information and the information on the received signal strength when the terminal identification information is received by the short-range communication unit 11 of the detection device 1 are recorded together in the terminal identification information history table.

[0198] Figure 24 is an example of a terminal identification information history table in this embodiment. The reception time and terminal identifier are the same as those described in Figures 5 and 6 of Example 1. The transmission output is the transmission output value (dBm) described in the terminal identification information, and the received signal strength is the received signal strength when the short-range communication unit 11 of the detection device 1 receives the terminal identification information.

[0199] In this embodiment, the distance DX between the vehicle 3 and the portable terminal 5 is calculated, and if the distance DX is equal to or less than a predetermined value V2, it is determined that the portable terminal 5 is carried by the user of the vehicle 3. The predetermined value V2 may be set according to the size of the vehicle 3, but may be set to, for example, 1 m, assuming the maximum value of the distance between the antenna of the short-range communication unit 11 and the position of an occupant in the same vehicle 3.

[0200] 25 is a flowchart showing the processing of the detection device 1 when the vehicle 3 is traveling. This processing is executed periodically at predetermined intervals T3. The interval T3 is, for example, one minute.

[0201] In S500, the control unit 10 acquires speed information from the vehicle speed detection unit 31 of the vehicle 3 and determines whether the vehicle 3 is currently traveling. For example, it may determine whether the speed is equal to or greater than a predetermined value. This predetermined value may be set, for example, to the minimum speed at which the vehicle 3 can travel stably (for example, 2 km / h). Alternatively, for example, it may be determined that the vehicle 3 is traveling if the speed remains equal to or greater than the predetermined value for a predetermined period of time or longer. If the vehicle 3 is traveling (S500: Yes), the process proceeds to S510. If the vehicle 3 is not traveling (S500: No), the process ends.

[0202] In S510, the control unit 10 initializes the ride list PL, and then proceeds to S520.

[0203] S520 to S570 are the same as S120 to S170 in Fig. 7, respectively. However, if S540: No, the process proceeds to S640. Also, if the number of receptions TR is equal to or greater than the predetermined number of times P1 (predetermined value P1) (S570: Yes), the process proceeds to S580. If the number of receptions TR is less than the predetermined number of times P1 (S570: No), the process proceeds to S630.

[0204] In S580, the control unit 10 extracts, from the processing target records R1, all records whose terminal identifier value is the same as the terminal identifier X as distance determination records R2. The distance determination records R2 consist of one or more records. Then, the process proceeds to S590.

[0205] In S590, the control unit 10 refers to the transmission output power and the received signal strength of each record in the distance determination record R2, and calculates the average transmission output power TSA and the average received signal strength RSA, and then proceeds to S600.

[0206] In S600, the control unit 10 uses, for example, equation (8) to calculate the distance DX between the vehicle 3 and the terminal with the terminal identifier X. Equation (8) is similar to equation (7).

[0207]

number

[0208] In S610, the control unit 10 determines whether the distance DX is equal to or less than a predetermined value V2. As described above, the predetermined value V2 is a value set based on the maximum distance within the same vehicle 3, for example, 1 m, so if the distance DX is equal to or less than the predetermined value V2, it can be determined that the terminal identifier was transmitted from within the same vehicle 3. If the distance DX is equal to or less than the predetermined value V2 (S610: Yes), the process proceeds to S620. If the distance DX is not equal to or less than the predetermined value V2 (S610: No), the process proceeds to S630.

[0209] In S620, the control unit 10 adds the terminal identifier X to the ride list PL. That is, when the distance DX is equal to or less than the predetermined value V2, the terminal identifier X is added to the ride list PL.

[0210] In S630, the control unit 10 deletes the terminal identifier X from the terminal identifier list TL. That is, since the terminal identifier X has been processed, it is deleted from the terminal identifier list TL. Thereafter, the process returns to S540 and the process is repeated.

[0211] In S640, the control unit 10 calculates (counts) the number of terminal identifiers recorded in the passenger list PL and determines whether or not this number exceeds the passenger capacity C. If the number of terminal identifiers exceeds the passenger capacity C (S640: Yes), the process proceeds to S650. If the number of terminal identifiers is equal to or less than the passenger capacity C (S640: No), the process ends.

[0212] S650 is the same as S250 in Fig. 8. That is, the control unit 10 records (stores) information indicating that the number of passengers exceeds the capacity in the storage unit 14. Note that the control unit 10 may omit S640, proceed from S540: No to S650, and store the detected number of passengers in the storage unit 14 regardless of whether the detected number of passengers exceeds the capacity C. For example, the control unit 10 may store the detected date and time and the number of passengers in the storage unit 14 in association with each other. Also, instead of proceeding from S540: No to S640, the control unit 10 may proceed from S540: No to S200 in Fig. 8 and execute S200 to S240. That is, instead of executing S640, S200 to S240 may be executed.

[0213] According to this embodiment, by calculating the distance between the vehicle 3 and the mobile terminal 5, the detection device 1 can exclude from detection targets mobile terminals 5 carried by persons other than the user of the vehicle 3, even if there are other vehicles 3 or pedestrians around the traveling vehicle 3 that are moving in the same direction and at the same speed as the vehicle 3. This makes it possible to determine the number of people in the vehicle 3 with higher accuracy.

[0214] Example 6 In the above embodiments, the number of passengers in the vehicle 3 is detected by the detection device 1 provided in the vehicle 3 or the detection device 1 that can be installed in the vehicle 3. In this embodiment, the number of people (number of users) using a building, facility, etc. is detected by the detection device 1 installed in a building, facility, etc.

[0215] 26 shows an example of the configuration of a detection system 9 in this embodiment. The detection system 9 includes detection devices 1A and 1B, and a management device 7. The configurations of the detection devices 1A and 1B used in this embodiment are the same as the configuration of the detection device 1 in Example 1 shown in FIG. 4. The management device 7 and the detection device 1A, and the management device 7 and the detection device 1B are connected via a wired or wireless network.

[0216] The management device 7 includes a control unit 70, a storage unit 74, and a communication unit 79. The control unit 70 controls the management device 7. The storage unit 74 stores various data and programs. At least a portion of the storage unit 74 is configured with non-volatile memory. The communication unit 79 communicates with the detection devices 1A and 1B via a network.

[0217] FIG. 27 is a diagram illustrating the installation locations of detection devices 1A and 1B in this embodiment. In the example shown in this figure, a building or a room within a building has an entrance and an exit, with detection device 1A installed on a wall near the entrance, and detection device 1B installed on a wall near the exit. In the example shown in this figure, detection device 1A is installed on the right wall near the entrance, and detection device 1B is set on the left wall near the exit, but it is optional whether they are installed on the right or left wall. Furthermore, detection devices 1A and 1B are not limited to being installed on walls, but may also be installed on the ceiling or floor of a room or corridor. The building or a room within the building may be, for example, a store, a conference room, an event venue, or an exhibition venue.

[0218] In this embodiment, it is desirable that the entrance and exit are separate. Also, a management device 7 capable of communicating with the detection devices 1A and 1B is installed. The management device 7 may be installed inside or outside a building or room.

[0219] In this embodiment, the terminal identification information history table stores the reception time, terminal identifier, and received signal strength in association with each other, as in the third embodiment. The detection device 1A is either adjusted in sensitivity so as not to receive radio waves transmitted from near the exit, or a threshold value for the received signal strength at the time of recording is set so that even if the detection device 1A receives radio waves, the received signal is not recorded in the terminal identification information history table.

[0220] In addition, the detection device 1B has its sensitivity adjusted so as not to receive radio waves transmitted from near the entrance, or a threshold value for the received signal strength at the time of recording is set so that even if it receives the signal, it is not recorded in the terminal identification information history table.

[0221] Fig. 28 is a diagram showing an example of changes in received signal strength detected by detection device 1A installed near the entrance and recorded in the terminal identification information history table of detection device 1A. As in Fig. 15, the horizontal axis of this diagram represents time and the vertical axis represents received signal strength, with the higher the graph, the higher (stronger) the received signal strength.

[0222] This figure also shows the change in received signal strength when two users, A and B, each carry two mobile terminals 5 and add an entrance. For example, user A passes through the entrance before user B, with the mobile terminal 5 with terminal identifier "1000" in his front pocket and the mobile terminal 5 with terminal identifier "2000" in his back pocket or in a backpack on his back. User B also passes through the entrance after user A, with the mobile terminal 5 with terminal identifier "3000" in his front pocket and the mobile terminal 5 with terminal identifier "4000" in his back pocket or in a backpack on his back.

[0223] Figure 29 is an example of signal strength time-series data corresponding to the graph in Figure 28. As in Figure 17, the four terminal identifiers "1000," "2000," "3000," and "4000" are included in the processing target record R1, and the received signal strength of each is recorded in dBm units every 200 milliseconds.

[0224] In this embodiment, each of the detection devices 1A and 1B groups terminal identifiers and detects the number of users based on the number of groups using one of the following methods. Hereinafter, when there is no need to particularly distinguish between the detection devices 1A and 1B, they may be simply referred to as "detection device 1."

[0225] [Method 1] As in the first embodiment, the detection device 1 groups the terminal identifiers based on the first time that the terminal identifiers are recorded in the terminal identification information history table. As described above, this first time may be the first time that the short-range communication unit 11 receives the signal, the first time that the received signal strength is equal to or greater than a predetermined value, or the first time that the received signal strength is equal to or greater than a predetermined value a predetermined number of times in succession.

[0226] [Method 2] The detection device 1 identifies the time (peak time) when the received signal strength reaches a maximum (peak) for each terminal identifier, and groups the terminal identifiers so that terminal identifiers whose peak time difference is less than a predetermined value (for example, 700 milliseconds) are grouped together. Unlike the previous embodiments, in this embodiment, the user approaches the detection device 1A or 1B and then moves away from it, so the received signal strength increases and then decreases, and a maximum point (peak point) occurs in the received signal strength.

[0227] 30 is a flowchart showing the processing flow of the detection devices 1A and 1B when using Method 2. The control units 10 of the detection devices 1A and 1B each periodically execute this processing at a predetermined cycle (for example, every 30 seconds).

[0228] In S700, the control unit 10 refers to the terminal identification information history table in the storage unit 14 and extracts all records whose reception time is within a predetermined period Q1 from the current time as records to be processed R1. The predetermined period Q1 in this embodiment may be a relatively short period (e.g., one minute), or may be the period from the time when entry and exit to a building or room becomes possible (e.g., 9:00 AM) to the current time. The predetermined period Q1 and the processing cycle may also be the same length (e.g., one minute).

[0229] In S710, the control unit 10 refers to the record R1 to be processed and calculates the peak time for each terminal identifier. The peak time is the time when the signal strength is at its maximum. In the example shown in FIG. 28, there is a peak point for each of the four terminal identifiers, and the respective peak times are Tc, Td, Te, and Tf. The control unit 10 detects such peak points and calculates the peak time. Note that if there are multiple peak points for one terminal identifier, the peak point with the highest received signal strength is adopted and that time is taken as the peak time.

[0230] In S720, the control unit 10 sorts the peak times in ascending order and calculates the difference (time difference) between adjacent peak times, for example, ΔTcd=Td−Tc, ΔTde=Te−Td, ΔTef=Tf−Te, etc.

[0231] In S730, the control unit 10 groups together terminal identifiers whose peak time difference is small. Specifically, the control unit 10 groups corresponding terminal identifiers into the same group when the difference between the peak times is equal to or less than a predetermined value (for example, 700 milliseconds). This predetermined value should be set assuming the moving speed of a person passing through an entrance and the maximum distance between multiple portable terminals 5 carried by the same person.

[0232] For example, assuming that a person's movement speed (walking speed) is a somewhat slow 1 meter per second, and the maximum distance between multiple mobile terminals 5 carried by the same person is 70 cm, the predetermined value is 700 milliseconds. In the example shown in Fig. 28, since ΔTcd and ΔTde are equal to or less than the predetermined value, terminal identifiers "1000" and "2000" are in the same group, and terminal identifiers "3000" and "4000" are in the same group.

[0233] The control unit 10 may group three or more terminal identifiers together. For example, when three peak times Th, Ti, and Tj are detected and the time difference ΔThj between the earliest time Th and the latest time Tj among them is equal to or less than a predetermined value (for example, 700 milliseconds), the control unit 10 may group the three terminal identifiers together.

[0234] In S740, the control unit 10 calculates (counts) the number of groups and sets it as the number of users (the number of people who passed near the detection device 1A or 1B).

[0235] [Method 3] As in the third embodiment, the detection device 1 groups a plurality of terminal identifiers whose temporal changes in received signal strength are similar. More specifically, the detection device 1 calculates an index (similarity) indicating the similarity between the terminal identifiers, and groups a plurality of terminal identifiers whose index meets a predetermined criterion into the same group. For example, terminal identifiers whose index is equal to or greater than a predetermined value may be grouped together. Also, as described above, three or more terminal identifiers may be grouped together.

[0236] In this way, the detection devices 1A and 1B each calculate the number of users (the number of people who passed near the detection device 1A and the number of people who passed near the detection device 1B) using any of methods 1 to 3. Then, the management device 7 performs control processing using this information.

[0237] 31 is a flowchart showing the flow of control processing in the management device 7. The control unit 70 of the management device 7 executes this processing at predetermined intervals (for example, every minute).

[0238] In S800, the control unit 70 acquires the number of users M1 detected by the detection device 1A from the detection device 1A via the network. The number of users M1 is the number of people who have passed through the entrance (number of entrants).

[0239] In S810, the control unit 70 acquires the number of users M2 detected by the detection device 1B from the detection device 1B via the network. The number of users M2 is the number of people who passed through the exit (the number of entrants, the number of exits).

[0240] In S820, the control unit 70 calculates the difference between the two types of user numbers to calculate the number of visitors. Specifically, it calculates a value ΔM (ΔM=M1-M2) by subtracting the number of users M2 of detection device 1B from the number of users M1 of detection device 1A. ΔM is the number of people entering minus the number of people leaving (number of people leaving), and is therefore the number of people staying in the building or room (number of visitors).

[0241] In S830, the control unit 70 determines whether the number of people staying exceeds the capacity C. The capacity C may be set appropriately depending on the size of the building, the characteristics of the facility, etc. For example, the capacity C may be set to 10 for a small store, and 3,000 for a large event venue.

[0242] Furthermore, in art galleries and the like where an increase in the number of people could result in unexpected contact with other people and damage to exhibits, the allowable population density per unit area may be set lower than in normal stores, and the capacity C may be set accordingly. The capacity C may also be set depending on the prevalence of infectious diseases and social conditions. For example, in situations where an infectious disease is prevalent or public safety is deteriorating, the capacity C may be set lower than usual.

[0243] If the number of visitors exceeds the capacity C (S830: Yes), the process proceeds to S840. If the number of visitors does not exceed the capacity C (S830: No), the process ends.

[0244] In S840, the control unit 70 records the number of visitors and implements entry restrictions, etc. Specifically, the control unit 70 associates the detection date and time, the number of users M1, the number of users M2, the number of visitors, and the like in the storage unit 74 of the management device 7 and stores them. The control unit 70 also controls, via the network, a display device installed near the entrance to display a message indicating that entry will be restricted because the capacity has been exceeded, or to close the entrance door or gate. This makes it possible to prevent visitors from significantly exceeding the capacity, preventing accidents and the spread of infection due to excessive visitors and improving the safety of buildings and facilities.

[0245] The control unit 70 may omit S830 and store the number of visitors in the memory unit 74 regardless of whether the number of visitors exceeds the capacity C. For example, the control unit 70 associates the detection date and time with the number of visitors and stores them in the memory unit 74. Even when such processing is performed, the detection system 9 can accurately record the transition (history) of the number of visitors (number of visitors) with a relatively simple system.

[0246] Also, for example, if the predetermined period Q1 and the processing cycle are each one minute, detection device 1A calculates the number of people entering per minute, and detection device 1B calculates the number of people leaving per minute, but the management device 7 may calculate these cumulative numbers. For example, in S820, the control unit 70 may calculate the cumulative number of people entering and leaving from the time when people became able to enter or leave the building or room (e.g., 9:00 AM) to the current time (e.g., 4:00 PM), and may use the value obtained by subtracting the cumulative number of people leaving from the cumulative number of people entering as ΔM (number of visitors).

[0247] In the above description, it is assumed that the management device 7 executes the process of Fig. 31, but this is not limiting. For example, at least one of the detection devices 1A and 1B may have the function of the management device 7 and execute the process of Fig. 31. In this case, it is sufficient that the detection devices 1A and 1B are connected via a network and can communicate with each other.

[0248] According to this embodiment, users of a building or facility do not need to perform any special operations, and the detection system 9 can accurately detect the number of people in a building or facility without imposing a burden on the users. Furthermore, compared to systems that detect the number of people by recognizing images of human bodies or faces using surveillance cameras or the like, this system is relatively inexpensive and simple, and is less likely to cause users concerns about privacy violations than systems that recognize images of human bodies or faces using surveillance cameras or the like.

[0249] <Modification 1 of Example 6> In the sixth embodiment, the detection devices 1A and 1B are installed in a building or the like with separate entrances and exits to detect the number of people staying there. In this modified example, the detection devices 1A and 1B are installed in a building or the like with no separate entrances and exits to detect the number of people staying there.

[0250] FIG. 32 is a diagram illustrating the installation locations of detection devices 1A and 1B in this modified example. In the example shown in this figure, there is one entrance to a building or a room within a building, and detection device 1A is installed on the wall to the right of the entrance when viewed from the outside, and detection device 1B is installed on the wall to the left of the entrance. In this modified example, it is desirable that the flow of entrants and exits be separated according to a predetermined rule such as "keep to the right." The arrows in FIG. 32 indicate the flow of users when keeping to the right.

[0251] The control unit 70 of the management device 7 acquires the terminal identification information history tables from the detection devices 1A and 1B. The control unit 70 then compares the received signal strengths of the two terminal identification information history tables at each time and classifies the data into data for which the detection device 1A has a stronger received signal strength (also referred to as right-side data) and data for which the detection device 1B has a stronger received signal strength (also referred to as left-side data) at the same time. Of course, data detected only on one side is considered to be data on the detected side. For example, data of a terminal identifier detected only by the detection device 1A is considered to be right-side data.

[0252] As described above, users pass through the entrances and exits in accordance with the "keep on the right" rule, so the received signal strength of the radio waves transmitted from the portable terminal 5 carried by the entrant will be stronger at detection device 1A. On the other hand, the received signal strength of the radio waves transmitted from the portable terminal 5 carried by the contestant (exiting person) will be stronger at detection device 1B. For this reason, the right-side data is likely to be radio waves transmitted from the portable terminal 5 of the entrant, and the left-side data is likely to be radio waves transmitted from the portable terminal 5 of the contestant.

[0253] Control unit 70 notifies detection device 1A of the right-side data and notifies detection device 1B of the left-side data. For example, control unit 70 may notify detection device 1A of a set of terminal identifiers corresponding to the right-side data and notify detection device 1B of a set of terminal identifiers corresponding to the left-side data. Control unit 70 may also notify detection device 1A of a combination of a reception time and a terminal identifier corresponding to the right-side data and notify detection device 1B of a combination of a reception time and a terminal identifier corresponding to the left-side data.

[0254] The detection devices 1A and 1B perform the same processing as in Example 6 on the notified data. Therefore, the detection device 1A can detect (calculate) the number of visitors M1, and the detection device 1B can detect (calculate) the number of participants (number of exiting visitors) M2. As in Example 6, the management device 7 can calculate the number of visitors based on the number of visitors M1 and the number of participants M2, and can perform control processing such as admission restriction based on the number of visitors.

[0255] The process of classifying the data into right-side data and left-side data may be performed not only by the management device 7 but also by the detection device 1A or the detection device 1B. For example, the detection device 1A may obtain the terminal identification information history table from the detection device 1B, compare it with its own terminal identification information history table, and classify the data into right-side data and left-side data. The detection device 1A may then notify the detection device 1B of the information about the left-side data, and the detection device 1A may process the right-side data and the detection device 1B may process the left-side data. Furthermore, after the management device 7 identifies the right-side data and the left-side data, the management device 7 may perform the same process as the detection device 1 based on the right-side data and the left-side data to calculate the number of entrants M1 and the number of contestants M2. In this case, there is no need to notify the detection device 1 of the right-side data and the left-side data.

[0256] According to this modification, even in a building or the like that does not have separate entrances and exits, the detection system 9 can accurately detect the number of visitors with a relatively simple configuration.

[0257] <Modification 2 of Example 6> In the sixth embodiment, the detection devices 1A and 1B are installed in a building or the like with separate entrances and exits to detect the number of people staying there. In this modified example, the detection devices 1A and 1B are installed in a building or the like with no separate entrances and exits to detect the number of people staying there.

[0258] FIG. 33 is a diagram illustrating the installation locations of detection devices 1A and 1B in this modified example. In the example shown in this figure, a building or a room in a building has one entrance / exit, and detection device 1A is installed on a wall or the like in front of the entrance (closer to the outside), and detection device 1B is installed on a wall or the like behind the entrance (closer to the inside). In the example shown in this figure, detection devices 1A and 1B are installed on the wall to the right of the entrance / exit, but they may be installed on either side of the wall. Furthermore, detection devices 1A and 1B are not limited to being installed on walls, and may also be installed on the ceiling or floor of a corridor or room. For example, detection device 1A may be installed on the ceiling in front of the entrance / exit, and detection device 1B may be installed on the ceiling behind the entrance / exit.

[0259] In the first modification of the sixth embodiment, it was assumed that the flow lines of visitors and spectators would be separated due to a predetermined rule such as "keep to the right," but in this modification, such a restriction is not necessary. The arrows in Figure 33 indicate that the flow lines of visitors and spectators are not separated.

[0260] The control unit 70 of the management device 7 acquires the terminal identification information history tables from the detection devices 1A and 1B. Then, the control unit 70 executes the same process as in S710 to calculate the peak time for each terminal identifier in each of the two terminal identification information history tables.

[0261] Radio waves transmitted from a mobile terminal 5 carried by a user entering a building or the like will first peak at detection device 1A, and then peak at detection device 1B. On the other hand, radio waves transmitted from a mobile terminal 5 carried by a user exiting (leaving) a building or the like will first peak at detection device 1B, and then peak at detection device 1A. This modified example utilizes this property to classify people into entrants and exiters.

[0262] Specifically, the control unit 70 compares the peak time of the detection device 1A with the peak time of the detection device 1B for each terminal identifier, and classifies the data into data for which the peak time of the detection device 1A is earlier (also called entry data) and data for which the peak time of the detection device 1B is earlier (also called exit data).

[0263] The control unit 70 notifies the detection device 1A of the entry data and notifies the detection device 1B of the exit data. For example, the control unit 70 may notify the detection device 1A of a set of terminal identifiers corresponding to the entry data and notify the detection device 1B of a set of terminal identifiers corresponding to the exit data.

[0264] The detection devices 1A and 1B perform the same processing as in Example 6 on the notified data. Therefore, the detection device 1A can detect (calculate) the number of visitors M1, and the detection device 1B can detect (calculate) the number of participants (number of exiting visitors) M2. As in Example 6, the management device 7 can calculate the number of visitors based on the number of visitors M1 and the number of participants M2, and can perform control processing such as admission restriction based on the number of visitors.

[0265] The process of classifying the data into entry data and exit data may be performed not only by management device 7 but also by detection device 1A or detection device 1B. For example, detection device 1A may obtain a terminal identification information history table from detection device 1B, compare it with its own terminal identification information history table, and classify the data into entry data and exit data. Detection device 1A may then notify detection device 1B of the entry data information, and detection device 1A may process the entry data and detection device 1B may process the exit data. Furthermore, after management device 7 identifies the entry data and exit data, it may perform the same process as detection device 1 based on them to calculate the number of entrants M1 and the number of contestants M2. In this case, there is no need to notify detection device 1 of the entry data and exit data.

[0266] According to this modified example, even in buildings where the entrance and exit are not separate, or even when the flow of visitors and visitors is not separate, the detection system 9 can accurately detect the number of visitors with a relatively simple configuration.

[0267] The functional components of the detection device 100, the detection device 1, the management device 7, and the vehicle 3 described above may be realized by hardware (e.g., a hardwired electronic circuit) that realizes the functional components, or may be realized by a combination of hardware and software (e.g., a combination of an electronic circuit and a program that controls it). For example, any process in the present disclosure can be realized by having a CPU execute a computer program.

[0268] The program includes instructions (or software code) that, when loaded into a computer, cause the computer to perform one or more functions described in the embodiments. The program may be stored on various types of non-transitory computer-readable medium or tangible storage medium. By way of example and not limitation, non-transitory computer-readable medium or tangible storage medium includes random-access memory (RAM), read-only memory (ROM), flash memory, solid-state drive (SSD) or other memory technology, CD-ROM, digital versatile disc (DVD), Blu-ray disc or other optical disk storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage device. The program may also be transmitted on various types of transitory computer-readable medium or communication medium. By way of example and not limitation, transitory computer-readable medium or communication medium includes electrical, optical, acoustic, or other forms of propagated signals.

[0269] The present disclosure is not limited to the above-described embodiments, and can be modified as appropriate without departing from the spirit and scope of the present disclosure. In addition, the above-described embodiments can be combined in any manner. [Explanation of symbols]

[0270] 1, 1A, 1B Detector 3 vehicles 5, 5A~5C mobile devices 7 Management device 9. Detection System 10 Control Unit 11 Near Field Communication Department 12 Vehicle Communication Unit 13 Timing section 14 Storage section 15 Display section 16 Control section 17 Audio output section 18 Location information identification section 19 Communications Department 31 Vehicle speed detection unit 32 Propulsion control unit 70 Control Unit 74 Memory section 79 Communications Department 100 Detection device 101 Receiving unit 102 Calculation section 103 Storage section

Claims

1. a receiving unit that receives, at a predetermined interval, radio waves including device identifiers transmitted from devices present in the vicinity; a calculation unit that acquires, for each device identifier, information indicating a reception status in each period of the radio waves received by the receiving unit during a predetermined period, groups the device identifiers based on a change over time in the reception status, and calculates the number of groups; a storage unit that stores the number of groups calculated by the calculation unit; A detection device comprising:

2. The calculation unit calculates time-series data based on signal strength in each period, calculates an index indicating a similarity between the calculated time-series data for each combination of the device identifiers, and groups the device identifiers by grouping the device identifiers together if the index satisfies a predetermined criterion. The detection device according to claim 1 .

3. The calculation unit identifies, for each device identifier, a time at which the receiving unit receives radio waves or a time at which the signal strength obtained by the receiving unit satisfies a predetermined condition, and groups the device identifiers by grouping a plurality of device identifiers whose identified times differ by within a predetermined time into the same group. The detection device according to claim 1 .

4. the storage unit further stores specific device information indicating specific devices that are unlikely to be carried by one person in plurality; the receiving unit further receives detailed information that enables determination of whether the device corresponding to the device identifier is the specific device; The calculation unit identifies the device identifier corresponding to the specific device based on the received detailed information and the stored specific device information, and adjusts parameters used in grouping so that the number of groups is equal to or greater than the number of the identified device identifiers. The detection device according to any one of claims 1 to 3.

5. a receiving step of receiving, at a predetermined interval, radio waves including device identifiers transmitted from devices present in the vicinity; a calculation step of acquiring, for each device identifier, information indicating a reception status in each cycle of the radio waves received in the receiving step during a predetermined period, grouping the device identifiers based on a temporal change in the reception status, and calculating the number of groups; a storage step of storing the number of groups calculated in the calculation step. program.

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