Terminal device and program

Abstract

To provide a terminal device that allows users of sound-emitting devices to easily understand the movement status of monitored devices. [Solution] The terminal device 100 according to this disclosure includes a receiving unit 101 that receives signals transmitted from another device equipped with an audio output unit, a sensor unit 102 that outputs displacement information indicating a change in the position or orientation of the device, a detection unit 103 that detects an abnormal state based on the signal strength or displacement information of the receiving unit 101, a generation unit 104 that generates an acoustic signal based on the displacement information when an abnormal state is detected by the detection unit 103, and a transmission unit 105 that transmits the acoustic signal generated by the generation unit 104 to another device. The generation unit 104 determines the movement state of the device based on the displacement information and generates a plurality of acoustic signals, each having at least one of the amplitude and frequency of the acoustic signal, corresponding to each of a plurality of movement states.

Description

Technical Field

[0001] The present disclosure relates to a terminal device and a program.

Background Art

[0002] There is a technology for detecting deterioration in the connection state between wirelessly connected devices and preventing the devices from becoming separated (for example, moving without noticing that one of the devices has been left behind). As a related technology, Patent Document 1 discloses a technology for notifying an abnormality by a sound such as a buzzer or a screen display when the signal quality of wireless communication between two devices falls below a preset quality level.

Prior Art Documents

Patent Documents

[0003] [[ID=2)]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the technology disclosed in Patent Document 1, although the user can grasp that the monitored device has moved away, the user cannot grasp the movement status of the monitored device. For example, if it is known whether the monitored device is moving or stationary, the user can easily determine whether theft has occurred or it is just left behind, but such a situation is not considered in the technology of Patent Document 1.

[0005] In recent years, a technology for wirelessly connecting a terminal device such as a smartphone and a device such as an earphone or a headset has become widespread. Generally, since these devices often do not have a display function, in order to notify the movement status of the terminal device using these devices, notification by sound is necessary.

[0006] In light of the aforementioned issues, the purpose of this disclosure is to provide a terminal device and program that allows users of sound-emitting devices to easily understand the movement status of monitored devices. [Means for solving the problem]

[0007] The terminal device relating to this disclosure is A receiving unit that receives signals transmitted from another device equipped with an audio output unit, This device includes a sensor unit that outputs displacement information indicating a change in position or orientation, A detection unit that detects an abnormal state based on the signal strength of the receiving unit or the displacement information, When an abnormal condition is detected by the detection unit, a generation unit generates an acoustic signal based on the displacement information, A transmitting unit that transmits the acoustic signal generated by the generation unit to the other device, Equipped with, The generation unit determines the movement state of the device based on the displacement information and generates multiple acoustic signals, each having at least one of the amplitude and frequency of the acoustic signal, corresponding to each of the multiple movement states.

[0008] The program related to this disclosure is A receiving step of receiving a signal transmitted from another device equipped with an audio output unit, An output step that outputs displacement information indicating a change in the position or orientation of this device, A detection step that detects an abnormal state based on the signal strength of the receiving step or the displacement information, If an abnormal condition is detected in the above detection step, a generation step is performed to generate an acoustic signal based on the displacement information, A transmission step of transmitting the acoustic signal generated in the generation step to the other device, A program that causes a computer to execute, In the generation step, the movement state of the device is determined based on the displacement information, and a plurality of acoustic signals are generated corresponding to each of the plurality of movement states, each having at least one of the amplitude and frequency of the acoustic signal being different. [Effects of the Invention]

[0009] The terminal device and program described herein enable users who use sound-emitting devices to easily understand the movement status of monitored devices. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a block diagram showing the configuration of the terminal device in the basic embodiment. [Figure 2] Figure 2 is a flowchart showing the processing flow in the terminal device of the basic embodiment. [Figure 3] Figure 3 is a block diagram showing the overall configuration of the communication system in Embodiment 1. [Figure 4] Figure 4 is a diagram illustrating the situation (use case) assumed in Embodiment 1. [Figure 5] Figure 5 is a flowchart showing the processing flow in the master unit according to Embodiment 1. [Figure 6] Figure 6 shows an example of the change in acceleration detected by the sensor unit of the master unit and the change in the signal strength of the slave unit detected by the short-range communication unit of the master unit in Pattern 1 of Embodiment 1. [Figure 7] Figure 7 is a diagram illustrating the situation (use case) assumed in Embodiment 2. [Figure 8] Figure 8 shows an example of the change in acceleration detected by the sensor unit of the master unit and the change in the signal strength of the slave unit detected by the short-range communication unit of the master unit in pattern 3 of embodiment 2. [Figure 9] Figure 9 is a flowchart showing the process flow for creating the reference range used to determine abnormal conditions in Embodiment 2. [Figure 10]FIG. 10 is a diagram showing changes in acceleration detected by the sensor unit of the master device and changes in the signal strength of the slave device detected by the short-range communication unit of the master device in Pattern 4 of Embodiment 3. [Figure 11] FIG. 11 is a flowchart showing a part of the processing in the master device according to Embodiment 3. [Figure 12] FIG. 12 is a flowchart showing a part of the processing in the master device according to Embodiment 3. [Figure 13] FIG. 13 is a flowchart showing the processing related to the generation of audio information in the master device according to Embodiment 4. [Figure 14] FIG. 14 is a configuration diagram of the communication system in Embodiment 5. [Figure 15] FIG. 15 is a diagram schematically showing the positional relationship between the user wearing the slave device and the master device according to Embodiment 5.

MODE FOR CARRYING OUT THE INVENTION

[0011] 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 denoted by the same reference numerals. For the sake of clarity of explanation, duplicate explanations are omitted as necessary.

[0012] <Basic Embodiment> 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 plurality of embodiments shown hereinafter, more detailed configuration examples, operation examples, etc. will be described.

[0013] (Terminal Device 100) Referring to FIG. 1, the terminal device 100 according to this embodiment will be described. FIG. 1 is a block diagram showing the configuration of the terminal device 100. The terminal device 100 includes a receiving unit 101, a sensor unit 102, a detecting unit 103, a generating unit 104, and a transmitting unit 105. The terminal device 100 is a device to be monitored.

[0014] The receiving unit 101 receives signals transmitted from other devices equipped with an audio output unit. The sensor unit 102 outputs displacement information indicating a change in the position or orientation of the terminal device 100 (this device). The detection unit 103 detects an abnormal condition based on the signal strength or displacement information from the receiving unit 101. An abnormal condition is, for example, a state in which the terminal device 100 has been stolen, misplaced, or dropped.

[0015] The generation unit 104 generates an acoustic signal based on displacement information when an abnormal condition is detected by the detection unit 103. The generation unit 104 determines the movement state of the terminal device 100 based on the displacement information and generates multiple acoustic signals corresponding to each of the multiple movement states, each having at least one different amplitude and frequency of the acoustic signal.

[0016] The generation unit 104 determines at least whether the terminal device 100 is stationary (at rest) as a movement status of the terminal device 100. If the terminal device 100 is stationary, it is highly likely that it has been left behind, and if the terminal device 100 is not stationary, it is highly likely that it has been stolen or dropped.

[0017] In this embodiment, the term "moving state" includes the stationary state, and the term "moving" is sometimes used to indicate a narrower "state of movement that is not stationary (while stationary)." Furthermore, "moving" includes the state in which the device was moving in the most recent past. The transmitting unit 105 transmits the acoustic signal generated by the generating unit 104 to another device.

[0018] The terminal device 100 includes a processor, memory, and storage device (not shown). The storage device stores a computer program on which the processing described herein is implemented. The processor can load the computer program from the storage device into memory and execute the computer program. In this way, the processor realizes the functions of the detection unit 103 and the generation unit 104.

[0019] Alternatively, the detection unit 103 and the generation unit 104 may each be implemented with dedicated hardware. Furthermore, some or all of the components may be implemented by general-purpose or dedicated circuits, processors, etc., or combinations thereof. These may be configured by a single chip or by multiple chips connected via a bus. Some or all of the components may be implemented by a combination of the aforementioned circuits, etc., and programs. Additionally, a CPU (Central Processing Unit), GPU (Graphics Processing Unit), FPGA (Field-Programmable Gate Array), quantum processor (quantum computer control chip), etc., can be used as the processor.

[0020] Furthermore, if some or all of the components of the terminal device 100 are implemented by multiple information processing devices or circuits, these multiple information processing devices or circuits may be centrally located or distributed. For example, the information processing devices or circuits may be implemented in a form in which each is connected via a communication network, such as a client-server system or a cloud computing system. In addition, some functions of the terminal device 100 may be provided in SaaS (Software as a Service) format.

[0021] (Processing by terminal device 100) The processing performed by the terminal device 100 will be explained with reference to Figure 2. Figure 2 is a flowchart showing the processing flow in the terminal device 100.

[0022] In S10, the receiving unit 101 receives a signal transmitted from another device. In S20, the sensor unit 102 outputs displacement information. In S30, the detection unit 103 detects an abnormal condition based on the signal strength or displacement information from the receiving unit 101.

[0023] If an abnormal condition is determined in S30 (S30: Yes), the process proceeds to S40. If no abnormal condition is determined in S30 (S30: No), the process returns to S10 and is repeated. In S40, the generation unit 104 generates multiple acoustic signals corresponding to each of the multiple movement states, with at least one of the amplitude and frequency being different, based on the displacement information. In S50, the transmission unit 105 transmits the acoustic signals generated by the generation unit 104 to other devices. The following are examples of acoustic signals generated by the generation unit 104, but are not limited to these.

[0024] (Example 1) When the terminal device 100 is stationary (in a stationary state), a small amplitude acoustic signal is generated, and when the terminal device 100 is not stationary, a large amplitude acoustic signal is generated. The frequencies of the small amplitude acoustic signal and the large amplitude acoustic signal may be the same or different. Note that when the terminal device 100 is not stationary, it can be said that the terminal device 100 is in motion.

[0025] Furthermore, the generation unit 104 may determine that the terminal device 100 is stationary if the displacement information is within a predetermined reference range, and determine that the terminal device 100 is not stationary (is moving) if the displacement information exceeds the predetermined reference range. For example, the generation unit 104 may determine that the device is stationary if the displacement information is below a predetermined value, and determine that the device is moving if the displacement information is greater than a predetermined value.

[0026] (Example 2) When the terminal device 100 is stationary, a low-frequency acoustic signal is generated, and when the terminal device 100 is not stationary, a high-frequency acoustic signal is generated. For example, a frequency in the range where human hearing is highly sensitive may be used as the high frequency, and a frequency lower than that may be used as the low frequency. The amplitudes of the low-frequency acoustic signal and the high-frequency acoustic signal may be the same or different.

[0027] (Example 3) When the terminal device 100 is stationary, an acoustic signal with a small amplitude and low frequency is generated, and when the terminal device 100 is not stationary, an acoustic signal with a large amplitude and high frequency is generated.

[0028] (Example 4) When the terminal device 100 is stationary, an acoustic signal with a small temporal change in amplitude is generated, and when the terminal device 100 is not stationary, an acoustic signal with a large temporal change in amplitude is generated. For example, as an acoustic signal with a small temporal change in amplitude, a sound with a constant amplitude that continues (sustained sound) may be used, and as an acoustic signal with a large temporal change in amplitude, a sound in which periods of large amplitude (e.g., 0.5 seconds) and periods of small amplitude (e.g., 0.5 seconds) are repeated alternately (e.g., with a 1-second period) (intermittent sound) may be used. Note that the period of small amplitude may be a period of zero amplitude, i.e., a silence period. Furthermore, not only sounds with discontinuously changing amplitudes but also sounds with continuously (smoothly) changing amplitudes may be used. Also, the frequencies of the sound with small amplitude changes and the sound with large amplitude changes may be the same or different.

[0029] (Example 5) When the terminal device 100 is stationary, an acoustic signal with a small temporal change in frequency is generated, and when the terminal device 100 is not stationary, an acoustic signal with a large temporal change in frequency is generated. For example, as an acoustic signal with a small temporal change in frequency, a sound with a constant frequency may be used, and as an acoustic signal with a large temporal change in frequency, a sound in which periods of high frequency (e.g., 0.5 seconds) and periods of low frequency (e.g., 0.5 seconds) alternate (e.g., with a 1-second period) may be used. Furthermore, not only sounds with discontinuous frequency changes but also sounds with continuous (smooth) frequency changes may be used. In addition, the amplitudes of the sound with a small frequency change and the sound with a large frequency change may be the same or different.

[0030] (Example 6) When the terminal device 100 is stationary, an acoustic signal with small temporal changes in amplitude and frequency is generated, and when the terminal device 100 is not stationary, an acoustic signal with large temporal changes in amplitude and frequency is generated. For example, as an acoustic signal with small temporal changes in amplitude and frequency, a sound may be used in which periods of small amplitude and low frequency and periods of large amplitude and high frequency are repeated over a long period (for example, a 4-second period), and the rate of change of amplitude and frequency is small (for example, the ratio of maximum amplitude to minimum amplitude is 150% or less).

[0031] For example, as an acoustic signal with large temporal changes in amplitude and frequency, a sound may be used in which periods of small amplitude and low frequency and periods of large amplitude and high frequency are repeated at short intervals (e.g., every 1 second), and the rate of change of amplitude and frequency is large (e.g., the ratio of maximum amplitude to minimum amplitude is 200% or more). As mentioned above, the amplitude and frequency may change continuously or discontinuously.

[0032] (Example 7) When the terminal device 100 is stationary, an acoustic signal with a constant amplitude and frequency is generated. When the terminal device 100 is not stationary, the timing for changing at least one of the amplitude and frequency is determined based on the displacement information, and an acoustic signal is generated. For example, if a person is holding the terminal device 100 in their hand and performing an action such as swinging their arm, the displacement changes periodically. The amplitude may be increased when the displacement increases (moves further from the reference position) and decreased when the displacement decreases (moves closer to the reference position).

[0033] In this case, the position with the arm hanging vertically down may be used as the reference position, the position with the arm swinging forward of the body may be considered the positive direction of displacement, and the position with the arm swinging backward of the body may be considered the negative direction of displacement. For example, the amplitude may be increased when the arm is swung widely forward or backward of the body, and decreased when the arm is hung vertically down. Of course, when decreasing the amplitude, it may also be possible to reduce the amplitude to zero to silence the sound.

[0034] Alternatively, for example, the amplitude could be increased when the arm swings widely in front of the body, and decreased at other times. In other words, the amplitude could be increased when the absolute value of the displacement is at its maximum, without considering the sign (direction) of the displacement, or it could be increased when the displacement is at its maximum in either the positive or negative direction, taking the sign (direction) of the displacement into consideration.

[0035] Alternatively, for example, the frequency may be increased when the displacement is large and decreased when the displacement is small. Or, for example, the frequency may be increased when the arm is swung widely in front of the body and decreased at other times. In other words, the frequency may be increased when the absolute value of the displacement is at its maximum, without considering the sign (direction) of the displacement, or the frequency may be increased when the displacement is at its maximum in either the positive or negative direction, considering the sign (direction) of the displacement. Of course, the amplitude may be increased and the frequency increased when the displacement is large, and the amplitude may be decreased and the frequency may be decreased when the displacement is small.

[0036] In this way, the generation unit 104 generates an acoustic signal in which at least one of the amplitude and frequency changes in synchronization with the displacement information. In this case, when the terminal device 100 is stationary, the displacement information is constant and does not change, so an acoustic signal with constant amplitude and frequency is generated.

[0037] As illustrated above, the generation unit 104 determines at least whether the terminal device 100 is stationary or not as a moving state of the terminal device 100, and generates a first acoustic signal corresponding to the stationary state (stationary) and a second acoustic signal corresponding to the non-stationary state (moving). The first and second acoustic signals only need to differ in at least one of their amplitude and frequency. By generating these two types of acoustic signals and outputting them to the audio output unit of another device, a user of the other device can instantly determine whether the terminal device 100, in which an abnormal state has been detected, is stationary or moving. In other words, a user can intuitively and easily infer that the terminal device 100 has been misplaced when they hear the first acoustic signal, and that the terminal device 100 has been stolen or dropped when they hear the second acoustic signal.

[0038] Furthermore, it is desirable to make the second acoustic signal a sound that is easier for the user to recognize (a prominent sound) compared to the first acoustic signal. As mentioned in the example above, it is desirable to make the second acoustic signal louder than the first acoustic signal, or to make the second acoustic signal a higher pitched sound than the first acoustic signal (a sound in a frequency range where hearing is highly sensitive). This processing is based on the understanding that if the terminal device 100 is moving when an abnormal condition occurs, there is a higher possibility that theft or dropping has occurred, and the user will need to take urgent action more than if it is stationary and there is a higher possibility of it being misplaced.

[0039] Furthermore, it is preferable to make the second acoustic signal a sound with greater variation (larger volume) compared to the first acoustic signal. As described in the example above, it is preferable to make the temporal change of at least one of the amplitude and frequency of the first acoustic signal relatively small, and the temporal change of at least one of the amplitude and frequency of the second acoustic signal relatively large. In other words, it is preferable that the second acoustic signal has a greater temporal change of at least one of the amplitude and frequency compared to the first acoustic signal.

[0040] For example, the rate of change of the amplitude of the first acoustic signal (the ratio of the maximum value to the minimum value of the amplitude) may be set to 120%, and the rate of change of the amplitude of the second acoustic signal may be set to 400%. Alternatively, for example, the rate of change of the frequency of the first acoustic signal (the ratio of the maximum value to the minimum value of the frequency) may be set to 120%, and the rate of change of the frequency of the second acoustic signal may be set to 200%.

[0041] Alternatively, for example, the period of change in the amplitude of the first acoustic signal may be 5 seconds, and the period of change in the amplitude of the second acoustic signal may be 1 second. Alternatively, for example, the period of change in the frequency of the second acoustic signal may be 5 seconds, and the period of change in the frequency of the second acoustic signal may be 1 second. In other words, it is preferable to make the amount of change (amount of change) of at least one of the amplitude and frequency of the second acoustic signal larger, or to increase the frequency of change (more frequently), compared to the first acoustic signal.

[0042] The term "large change" is sometimes used to describe both large amounts of change and frequent changes. This type of processing is based on the understanding that users can easily associate small changes in sound with the stationary state of an object, and large changes in sound with the movement of an object. By generating such acoustic signals, users can intuitively and easily grasp the movement state of the terminal device 100.

[0043] In the above explanation, two movement states for the terminal device 100 were used: stationary and moving. However, the system is not limited to these two, and three or more movement states may be used. For example, the generation unit 104 may determine that the terminal device 100 is stationary when the displacement information is less than a first predetermined value, determine that the terminal device 100 is moving slightly when the displacement information is greater than or equal to the first predetermined value and less than a second predetermined value, and determine that the terminal device 100 is moving significantly when the displacement information is greater than or equal to the second predetermined value.

[0044] Here, the second predetermined value is a value greater than the first predetermined value. The generation unit 104 may, for example, generate an acoustic signal with constant amplitude and frequency when stationary, generate an acoustic signal with constant frequency and changing amplitude when moving slightly, and generate an acoustic signal with changing amplitude and amplitude when moving significantly.

[0045] For example, the generation unit 104 may generate an acoustic signal with constant amplitude and frequency when stationary, generate an acoustic signal with amplitude and frequency that changes small (e.g., with a rate of change of 150%) with a long period (e.g., a 4-second period) when moving small, and generate an acoustic signal with amplitude and frequency that changes large (e.g., with a rate of change of 300%) with a short period (e.g., a 1-second period) when moving large.

[0046] As described above, when an abnormal condition is detected, the terminal device 100 generates an acoustic signal based on the displacement information and transmits the generated acoustic signal to another device equipped with an audio output unit. This allows users of other devices to easily understand the movement status of the terminal device 100.

[0047] <Embodiment 1> Next, Embodiment 1 will be described. Embodiment 1 is a specific example of the basic embodiment described above. Figure 3 is a block diagram showing the overall configuration of the communication system in Embodiment 1. The communication system consists of a master unit 1 (first communication device) and a slave unit 3 (second communication device). The master unit 1 is an example of the terminal device 100 described above. The slave unit 3 is an example of another device described above.

[0048] (Main unit 1) The master unit 1 consists of a communication unit 11, a position detection unit 12, a sensor unit 13, a light-emitting unit 14, a processing unit 15, a display unit 16, a storage unit 17, and an audio unit 18.

[0049] The communication unit 11 includes a long-distance communication unit 111 and a short-distance communication unit 112. The long-distance communication unit 111 communicates using, for example, a mobile phone line or an internet line via a wireless LAN (Local Area Network).

[0050] The short-range communication unit 112 is an example of the receiving unit 101 and transmitting unit 105 described above. The short-range communication unit 112 (receiving unit) receives signals transmitted from the slave unit 3. The short-range communication unit 112 (transmitting unit) transmits the acoustic signal generated by the processing unit 15 (generation unit) to the slave unit 3.

[0051] The position detection unit 12 detects the position of the base station 1 and outputs position information. The position detection unit 12 detects the position of the base station 1 using, for example, a GNSS (Global Navigation Satellite System) system, mobile phone base station information, wireless LAN access point information, or an indoor positioning system. The position information may be (latitude, longitude) or it may be the direction and distance based on a predetermined point (for example, a place inside a building).

[0052] The sensor unit 13 is an example of the sensor unit 102 described above. The sensor unit 13 outputs displacement information indicating a change in the position or orientation of the master unit 1. In other words, the sensor unit 13 outputs information indicating the movement or motion state of the master unit 1. If the position or orientation of the master unit 1 has changed, it means that the master unit 1 is moving, and if the position and orientation of the master unit 1 have not changed, it means that the master unit 1 is stationary. Therefore, it is possible to determine whether the master unit 1 is stationary or moving based on the displacement information. That is, the motion state (movement status) of the master unit 1 can be determined by the displacement information output by the sensor unit 13. In this embodiment, the motion state is a concept that includes the stationary state, and is not limited to the linear movement of the master unit 1, but also includes rotational movement.

[0053] Since acceleration, velocity, and displacement are mutually convertible, acceleration information can be used as displacement information, for example. In this embodiment, the sensor unit 13 includes an acceleration sensor that detects acceleration in the three axes of X, Y, and Z, and acceleration information is used as displacement information, but it is not limited to this. For example, the sensor unit 13 may include a gyro sensor (angular velocity sensor), and angular velocity may be used as displacement information. In other words, the displacement information may also be information indicating a change in the orientation of the master unit 1.

[0054] Furthermore, the temporal change in position information detected by the position detection unit 12 may be used as displacement information. More specifically, the amount of change in position information per unit time (for example, 0.1 seconds or 1 second) may be used as displacement information. For example, the change (amount of change) in the position (latitude, longitude) of the master unit 1 at a predetermined point in time may be used as displacement information.

[0055] Alternatively, for example, the displacement information may be the change (amount of change) in direction and distance after the position of the master unit 1 at a predetermined point in time. The reference position may also be the position of the master unit 1 measured previously and updated each time. In this way, when using temporal changes in position information as displacement information, it is possible to omit acceleration sensors and implement the sensor unit 13 with hardware common to the position detection unit 12. Furthermore, in addition to the function of outputting displacement information, the sensor unit 13 may also have functions for measuring illuminance, temperature, atmospheric pressure, etc., around the master unit 1.

[0056] The light-emitting unit 14 illuminates the area around the master unit 1. The light-emitting unit 14 is a light source such as an LED (Light Emitting Diode). The light-emitting unit 14 notifies of an abnormality in the master unit 1 by lighting up or flashing.

[0057] The processing unit 15 is an example of the detection unit 103 and generation unit 104 described above. The processing unit 15 (detection unit) detects an abnormal state based on the signal strength or displacement information of the short-range communication unit 112 (receiving unit). When an abnormal state is detected, the processing unit 15 (generation unit) generates an acoustic signal based on the displacement information. The processing unit 15 determines the movement state of the master unit 1 based on the displacement information and generates multiple acoustic signals corresponding to each of the multiple movement states, each having at least one different amplitude and frequency of the acoustic signal.

[0058] For example, the processing unit 15 generates a first acoustic signal in which the amplitude and frequency of the acoustic signal are constant when the displacement information is within a predetermined reference range. Furthermore, when the displacement information exceeds a predetermined reference range, the processing unit 15 determines the timing to change at least one of the amplitude and frequency of the acoustic signal according to the displacement information, and generates a second acoustic signal in which at least one of the amplitude and frequency is changed.

[0059] The first acoustic signal is typically a sound with a constant amplitude and frequency that lasts for a predetermined time or longer, but it is sufficient if the amplitude and frequency change is relatively small compared to the second acoustic signal. In other words, the first acoustic signal does not necessarily have to be a sound with constant (unchanging) amplitude and frequency.

[0060] The display unit 16 displays various information. The display unit 16 may be configured using a touch panel that functions as an interface for receiving operations from the user of the master unit 1.

[0061] The memory unit 17 stores various data and programs. At least a portion of the memory unit 17 is composed of non-volatile memory so that necessary data is retained even when the power to the master unit 1 is turned off.

[0062] The audio unit 18 includes an audio output unit 182 (speaker, etc.) that outputs sound and an audio input unit 181 (microphone, etc.) that inputs (collects) sound.

[0063] (Handset 3) The sub-unit 3 consists of a short-range communication unit 312, a processing unit 35, a storage unit 37, an audio unit 38, and an operation unit 39.

[0064] The short-range communication unit 312 communicates with the short-range communication unit 112 of the master unit 1. The short-range communication unit 312 receives signals transmitted from the master unit 1. The short-range communication unit 312 also transmits signals to the master unit 1.

[0065] The processing unit 35 performs various processes in the slave unit 3. For example, the processing unit 35 acquires the acoustic signal received by the short-range communication unit 312 and causes the audio unit 38 to output the acoustic signal. Also, when the processing unit 35 receives an instruction from the operation unit 39 to stop the acoustic signal, it causes the short-range communication unit 312 to send a message to stop the acoustic signal.

[0066] The memory unit 37 stores various data and programs. The audio unit 38 includes at least an audio output unit 382 that outputs sound. The audio unit 38 may also include an audio input unit 381 that receives sound. The operation unit 39 receives user input for the slave unit 3. The operation unit 39 is composed of buttons, dials, etc.

[0067] The master unit 1 and the slave unit 3 are connected by short-range wireless communication via their respective short-range communication units. The short-range communication units 112 and 312 communicate, for example, via Bluetooth (registered trademark, hereinafter the same) or wireless LAN, but are not limited to these. When the slave unit 3's short-range communication unit 312 transmits data to the master unit 1, it may also transmit information indicating the transmission output of the slave unit 3's radio waves. Similarly, when the master unit 1's short-range communication unit 112 transmits data to the slave unit 3, it may also transmit information indicating the transmission output of the master unit 1's radio waves.

[0068] The master unit 1 is, for example, a mobile phone, smartphone, tablet device, personal computer, or professional radio. The slave unit 3 is a peripheral device of the master unit 1, and is, for example, a headset, earphones, headphones, speaker, smartwatch, VR (Virtual Reality) goggles, or wearable device. In this embodiment, the case where the slave unit 3 is a headset, earphones, or headphones will be described as an example, but of course, it is not limited to these.

[0069] Furthermore, the master unit 1 and the slave unit 3 may be the same type of device; for example, the slave unit 3 may be a smartphone. For example, both the master unit 1 and the slave unit 3 may be smartphones, and the master unit 1 may communicate with an internet server etc. using a long-range communication unit 111 (such as a mobile phone line), and the slave unit 3 may connect to the master unit 1 using a short-range communication unit 312 (such as wireless LAN or Bluetooth), and access the internet via the master unit 1, performing what is known as tethering.

[0070] Figure 4 is a diagram illustrating the situation (use case) assumed in Embodiment 1. As shown in Figure 4(a), the master unit 1 is placed on a table or the like, and the user is using the slave unit 3 at a short distance away. For example, the slave unit 3 is a headset, and the slave unit 3 outputs the audio received from the master unit 1 to the user, picks up the voice spoken by the user and transmits it to the master unit 1, allowing the user to make a voice call or participate in an online meeting. In other words, in this situation, the master unit 1 is used while stationary for at least a certain period of time.

[0071] Next, we consider a scenario where the main unit 1 is taken away by someone other than the user (hereinafter referred to as the perpetrator), as shown in Figure 4(b). In this case, the main unit 1 rapidly transitions from a stationary state to a moving state. The situation shown in Figure 4(b) may hereafter be referred to as Pattern 1 (Theft / Loss Pattern 1).

[0072] Furthermore, we also consider the possibility that the situation shown in Figure 4(c) may occur after the situation shown in Figure 4(a). Figure 4(c) shows a situation where the user leaves the table and moves to another location, leaving the main unit 1 behind, resulting in the main unit 1 being forgotten. The situation shown in Figure 4(c) may be referred to below as Pattern 2 (Theft / Loss Pattern 2).

[0073] In this embodiment, theft as shown in Figure 4(b) and misplacement as shown in Figure 4(c) are detected early, and the status of the master unit 1 is notified to the user using the slave unit 3 using sound.

[0074] (Processing by Master Unit 1) Figure 5 is a flowchart showing the processing flow in the master unit 1. In S100, the processing unit 15 of the master unit 1 acquires the signal strength of the radio waves transmitted from the slave unit 3, which are received by the short-range communication unit 112 (receiving unit) (hereinafter also referred to as "signal strength of slave unit 3" or "signal strength").

[0075] In S110, the processing unit 15 of the master unit 1 acquires acceleration information from the sensor unit 13. As mentioned above, acceleration information is a representative example of displacement information that indicates the movement of the master unit 1, and the processing unit 15 may also acquire the amount of change in position information or angular velocity information.

[0076] In S120, the processing unit 15 of the master unit 1 acquires position information from the position detection unit 12. In S130, the processing unit 15 of the master unit 1 determines whether or not an abnormal condition has occurred based on the information acquired in S100 to S120.

[0077] Figure 6 shows an example of the change in acceleration detected by the sensor unit 13 of the master unit 1 and the change in signal strength of the slave unit 3 detected by the short-range communication unit 112 of the master unit 1 when pattern 1 shown in Figure 4(b) occurs. Note that the acceleration in this figure represents the average value of the acceleration in the three axes. During the period up to time A, the master unit 1 is stationary on the table, so a nearly constant acceleration (equivalent to 1G) corresponding to the acceleration due to gravity is detected.

[0078] At time point A, a large acceleration is generated because the perpetrator lifted the master unit 1 from the table or other surface. Subsequently, the perpetrator quickly leaves, so periodic acceleration associated with walking or running is observed. Also, as the perpetrator gradually moves away from the slave unit 3, the signal strength decreases.

[0079] However, depending on the escape route taken by the perpetrator, the distance to the sub-unit 3 may temporarily decrease, so the signal strength does not necessarily decrease monotonically, and as shown in Figure 6, the signal strength may temporarily increase. On the other hand, although not shown in the illustration, if pattern 2 shown in Figure 4(c) occurs, the acceleration does not change, and the signal strength decreases over time, similar to Figure 6.

[0080] In S130, the processing unit 15 of the master unit 1 detects an abnormal state based on the changes in signal strength and acceleration as shown in Figure 6. Specifically, the processing unit 15 determines that an abnormal state exists if at least one of the following conditions is met.

[0081] (Anomaly detection 1) The signal intensity has decreased to below the first predetermined value (first threshold). For example, in the example in Figure 6, at time point B, the signal strength drops below the first threshold, so an abnormal condition is detected. It is desirable that the first threshold is not the signal strength at which communication between the slave unit 3 and the master unit 1 becomes impossible, but rather a value somewhat higher than the limit at which communication becomes impossible.

[0082] (Anomaly detection 2) The signal strength dropped sharply, exceeding a predetermined rate of decrease. For example, the predetermined reduction rate may be set to a signal intensity decrease of 15% or more per second.

[0083] (Anomaly detection 3) The distance calculated based on the signal strength and the transmission output of the slave unit 3 has exceeded a predetermined value. For example, the processing unit 15 may detect an abnormal condition when the distance between the two becomes 5 meters or more.

[0084] (Anomaly detection 4) The acceleration has exceeded the second predetermined value (second threshold). For example, in the example shown in Figure 6, at time point A, the acceleration exceeds the second threshold, so an abnormal condition is detected. The second threshold may be a pre-set value (fixed value), but it may also be set dynamically as described later.

[0085] (Anomaly detection 5) The period of acceleration meets the predetermined standard. For example, the processing unit 15 may set a predetermined criterion to a period shorter than 1 second and detect an abnormal state when a period shorter than 1 second is observed.

[0086] (Anomaly detection 6) The location information of master unit 1 has exceeded a predetermined range. As described above, the location information may be (latitude and longitude), or it may be the direction and distance relative to a predetermined point. For example, the processing unit 15 may determine that a predetermined range has been exceeded when the location is more than 10 meters away from the predetermined point.

[0087] (Anomaly detection 7) The movement speed (displacement per unit time) of the master unit 1 has exceeded a predetermined value.

[0088] Furthermore, when angular velocity information is used as displacement information, the processing unit 15 may detect an abnormal state when the angular velocity of the master unit 1 exceeds a predetermined value, that is, when the change in the orientation of the master unit 1 exceeds a predetermined standard. Also, the processing unit 15 may determine that an abnormal state exists when any combination of the above-mentioned conditions is satisfied in an AND condition. For example, the processing unit 15 may determine that an abnormal state exists when both (abnormal detection 1) and (abnormal detection 4) are satisfied. If (abnormal detection 1) to (abnormal detection 3) are not used, S100 can be omitted. Also, if (abnormal detection 6) is not used, S120 can be omitted.

[0089] Returning to the explanation of Figure 5, if an abnormal state is determined in S130 (S130: Yes), proceed to S140. If an abnormal state is not determined in S130 (S130: No), return to S100 and repeat the process.

[0090] In S140, the processing unit 15 of the master unit 1 determines the state of movement of the master unit 1 (also called the displacement state or movement state). Specifically, the processing unit 15 determines whether the master unit 1 is stationary (at rest). If the master unit 1 is not stationary, then the master unit 1 is moving. In this determination, the processing unit 15 may use the data acquired in S110 to S120, or it may acquire and use data continuously (for example, every 50 milliseconds). The processing unit 15 only needs to make the determination using at least one of the methods shown below.

[0091] 1) If the maximum acceleration value obtained from the sensor unit 13 is less than the third predetermined value, it is determined to be stationary; if the maximum acceleration value is equal to or greater than the third predetermined value, it is determined to be in motion. The third predetermined value may be the same as the second predetermined value, or it may be a smaller value than the second predetermined value.

[0092] 2) When the sensor unit 13 outputs displacement information, for example, the amount of change in position information every second, it is determined to be stationary if the amount of change in position information is less than a predetermined value, and it is determined to be moving if the amount of change in position information is equal to or greater than the predetermined value.

[0093] In other words, methods 1) and 2) can be described as the processing unit 15 determining that the device is stationary or "not moving" when the displacement information is within a predetermined reference range, and determining that it is moving or "moving" when the displacement information exceeds the predetermined reference range.

[0094] 3) If the position information obtained from the position detection unit 12 falls within a predetermined range, it is determined to be stationary; if it exceeds the predetermined range, it is determined to be moving. For example, the processing unit 15 may set the predetermined range to a radius of 2 meters from a reference position (e.g., the position of a table or desk), determine that the master unit 1 is stationary if its position information is within the predetermined range, and determine that it is moving if its position information exceeds the predetermined range. Alternatively, the predetermined range may be set to avoid false detections, taking into account the error of the position detection unit 12. When angular velocity information is used as displacement information, the processing unit 15 may determine that the master unit 1 is stationary if the maximum value of its angular velocity is less than a predetermined value, and determine that it is moving if the maximum value of its angular velocity is equal to or greater than the predetermined value.

[0095] Furthermore, multiple conditions may be combined using AND conditions. For example, conditions 1) and 3) above may be combined using AND conditions. For example, the processing unit 15 may determine that the device is stationary when the maximum value of acceleration is less than a third predetermined value and the change in position information falls within a predetermined range. Such processing can reduce malfunctions caused by detection errors in the sensor unit 13 and the position detection unit 12.

[0096] If master unit 1 is stationary (S140: Yes), proceed to S150; otherwise, proceed to S160.

[0097] In S150, the processing unit 15 of the master unit 1 generates (creates) an acoustic signal indicating that the master unit 1 is stationary (no displacement). This acoustic signal is called the first acoustic signal or (acoustic signal 1). (Acoustic signal 1) is typically a sustained sound with a constant amplitude.

[0098] For example, the processing unit 15 generates a sustained sound in which a constant amplitude is maintained for a predetermined time or longer. Alternatively, the processing unit 15 may generate a sustained sound in which a constant amplitude and frequency are maintained for a predetermined time or longer. For example, the processing unit 15 may generate a sustained sound with a relatively low frequency (a pitch lower than the predetermined frequency), such as a "boom." The process proceeds from S150 to S170.

[0099] In S160, the processing unit 15 of the master unit 1 generates an acoustic signal indicating that the master unit 1 is moving (displaced). This acoustic signal is called the second acoustic signal or (acoustic signal 2). Acoustic signal 2 is typically an intermittent sound, where the sound occurs intermittently. This intermittent sound is also called a click sound.

[0100] An intermittent sound is a sound in which the period of sound output and the period of silence are repeated in short cycles, such as "beep, beep, beep, beep." In other words, an intermittent sound is a sound in which the sound output and silence are repeated alternately. Alternatively, an intermittent sound does not have to be completely silenced, and may be a sound in which periods of high volume (amplitude) and periods of low volume are repeated alternately. In particular, it is preferable for the processing unit 15 to determine the timing of sound output in synchronization with acceleration or displacement.

[0101] As mentioned above, acceleration, velocity, and displacement are mutually convertible, and in periodic motion such as swinging an arm, the displacement is also maximum at the time when the acceleration is maximum. For example, if the perpetrator swings their arm while holding the master unit 1 while walking, in the acceleration graph of Figure 6, the acceleration is maximum at time t1 when the arm is furthest forward, and minimum at time t2 when the arm is furthest back. For example, in the case of intermittent sounds such as "beep, beep, beep, beep," the "beep" sound is output at times t1 and t2.

[0102] Depending on how the sign of acceleration is taken, the maximum and minimum points may be reversed, but in any case, the processing unit 15 can generate a sound that synchronizes with the perpetrator's movements (behavior) by outputting sound around the point of maximum absolute value of acceleration and generating an intermittent sound that stops around the point where the acceleration is near zero. Alternatively, by considering the positive or negative sign of acceleration and outputting a "beep" sound at either timing t1 or t2, it is possible to generate a sound that synchronizes with the perpetrator's movements (behavior).

[0103] Furthermore, the processing unit 15 may generate an acoustic signal (acoustic signal 2) that alternately outputs high-pitched sounds (high-frequency sounds) and low-pitched sounds (low-frequency sounds). For example, the processing unit 15 may generate an acoustic signal such as "peep-peep." More specifically, the processing unit 15 may generate an acoustic signal that outputs high-pitched sounds around the point of maximum absolute value of acceleration and low-pitched sounds around the point where acceleration is near zero. In this way, it is possible to generate sounds that are synchronized with the actions (behavior) of the perpetrator. In this case, the amplitudes of the high-pitched sound and the low-pitched sound may be the same or different. That is, (acoustic signal 2) may be a sound with a constant frequency and changing amplitude, or a sound with a constant amplitude and changing frequency, or a sound with changing amplitude and frequency.

[0104] Here, we have described typical examples of (acoustic signal 1) and (acoustic signal 2), but we are not limited to these. For example, (acoustic signal 2) may be a sound with a louder volume (amplitude) than (acoustic signal 1). For example, (acoustic signal 2) is not limited to an intermittent sound, but may be a sound with a constant amplitude and a larger amplitude than (acoustic signal 1).

[0105] Furthermore, for example, (acoustic signal 2) may have a higher pitch (frequency) than (acoustic signal 1). For example, (acoustic signal 2) is not limited to an intermittent sound, but may have a constant frequency and a higher frequency than (acoustic signal 1). In other words, (acoustic signal 1) and (acoustic signal 2) only need to be acoustic signals that differ in at least one of their amplitude and frequency.

[0106] However, it is preferable that (acoustic signal 2) is a more noticeable sound (a sound that easily attracts the user's attention) than (acoustic signal 1). Furthermore, it is preferable that (acoustic signal 1) is a sound with little (little) temporal change so that the user associates it with stillness, and it is preferable that (acoustic signal 2) is a sound with a large (many) temporal change so that the user associates it with movement. Proceed from S160 to S170.

[0107] In S170, the processing unit 15 of the master unit 1 stops the original audio output. For example, the processing unit 15 controls the short-range communication unit 112 of the master unit 1 to stop outputting call audio data or music data that was being output to the slave unit 3. At this time, the short-range communication unit 112 of the master unit 1 may also send a message to the slave unit 3 to increase the transmission output of the radio waves of the slave unit 3. Also, if S170 is executed for the second time or later, the original audio output has already been stopped, so S170 is skipped and the process proceeds to S180.

[0108] In S180, the processing unit 15 of the master unit 1 causes the acoustic signal (notification sound) generated in S150 or S160 to be transmitted to the short-range communication unit 112 of the master unit 1. The short-range communication unit 112 of the master unit 1 transmits the generated acoustic signal to the slave unit 3. When the short-range communication unit 312 of the slave unit 3 receives the acoustic signal (notification sound), the processing unit 35 of the slave unit 3 acquires the received acoustic signal and causes the audio unit 38 (audio output unit 382) of the slave unit 3 to output the acoustic signal.

[0109] The state of the master unit 1 during the period when the slave unit 3 is emitting an alert sound is sometimes referred to as alert mode. The user of slave unit 3 can easily (instantly) understand the movement status of the master unit 1 by listening to the alert sound.

[0110] In other words, if (sound signal 1) is heard, it is understood that the base unit 1 is stationary, so the user can conclude that they have left the base unit 1 behind. Therefore, the user can calmly recall where they left the base unit 1 and return there. On the other hand, if (sound signal 2) is heard, it is understood that the base unit 1 is moving, so the user can quickly identify the culprit by looking around and searching for someone performing an action synchronized with the timing of the intermittent sound.

[0111] The user of the slave unit 3 may issue a notification stop command by operating the control unit 39 of the slave unit 3. For example, if the user has found the misplaced master unit 1, or has identified the culprit and recovered master unit 1, and has determined that further notification sound output is no longer necessary, the user will issue a notification stop command by performing a predetermined operation. When the processing unit 35 of the slave unit 3 receives a notification stop command from the control unit 39, it will send a notification stop message to the short-range communication unit 312.

[0112] The user of the slave unit 3 may also issue an alarm output instruction by operating the control unit 39 of the slave unit 3. For example, if the user cannot find the misplaced master unit 1, or if the culprit cannot be identified, and it is determined that further searching is difficult on their own, the user will issue an alarm output instruction by performing a predetermined operation. When the processing unit 35 of the slave unit 3 receives an alarm output instruction from the control unit 39, it will send an alarm output message to the short-range communication unit 312.

[0113] In S190, the processing unit 15 of the master unit 1 determines whether or not it has received a notification stop message via the short-range communication unit 112. If a notification stop message is received (S190: Yes), the process proceeds to S200. If a notification stop message is not received (S190: No), the process proceeds to S220.

[0114] In S200, the processing unit 15 of the master unit 1 controls the short-range communication unit 112 of the master unit 1 to stop transmitting the notification sound. In other words, it terminates the notification mode. The processing unit 15 may stop outputting the notification sound not only when it receives a notification stop message. For example, the processing unit 15 may stop outputting the notification sound after a predetermined time (for example, 3 minutes) has elapsed since outputting the notification sound.

[0115] In S210, the processing unit 15 of the master unit 1 resumes the original audio output. That is, the processing unit 15 controls the short-range communication unit 112 of the master unit 1 to resume outputting the call audio data and music data that were being output to the slave unit 3 before the abnormal condition occurred. After that, the process ends.

[0116] In S220, the processing unit 15 of the master unit 1 determines whether or not it has received an alarm output message via the short-range communication unit 112. If an alarm output message is received (S220: Yes), the process proceeds to S230. If an alarm output message is not received (S220: No), the process returns to S140 and is repeated.

[0117] The processing unit 15 may periodically repeat the processing from S140 to S220 (for example, every second). The processing unit 15 may use a timer to adjust the repetition period. The processing unit 15 may also adjust the length of the generated acoustic signal according to the repetition period. For example, if the repetition period is 1 second, the processing unit 15 may set the length of the (acoustic signal 1) generated at one time to 1 second so that the (acoustic signal 1) is played continuously and the sound is not interrupted.

[0118] In S230, the processing unit 15 of the master unit 1 transitions to alarm mode and controls the audio output unit 182 of the master unit 1 to output an alarm sound. Alarm mode indicates the state of the master unit 1 during the period in which the alarm sound is being output from the master unit 1.

[0119] The audio output unit 182 emits a loud alarm sound to the surrounding area. This makes it easier for the user of the slave unit 3 to determine the location of the master unit 1. In addition, people nearby will know that some kind of abnormal situation has occurred at the perpetrator's location, thus increasing the likelihood that the user of the slave unit 3 and those nearby can cooperate to apprehend the perpetrator.

[0120] In this process, the processing unit 15 of the master unit 1 may control the light-emitting unit 14 to illuminate the surroundings with light corresponding to the alarm mode. Alternatively, the processing unit 15 of the master unit 1 may control the display unit 16 to display a screen or message corresponding to the alarm mode. The display unit 16 may display a message such as, for example, "This master unit 1 has been stolen." After this, the process is terminated.

[0121] In this embodiment, the main unit 1 does not immediately emit an alarm sound. This is to reduce the risk that the perpetrator may be startled by the alarm sound and flee before the user can identify them. It also reduces the risk of causing a nuisance to the surroundings due to a malfunction.

[0122] According to this embodiment, the master unit 1 generates multiple acoustic signals indicating its movement status (movement status), such as whether it is stationary or moving, and transmits them to the slave unit 3. As a result, the user of the slave unit 3 can intuitively and easily grasp the movement status of the master unit 1. In other words, the user can instantly determine whether the master unit 1 is stationary or moving simply by listening to the sound. Therefore, the user can instantly determine whether they have left the master unit 1 behind or whether the master unit 1 has been stolen. Furthermore, since intermittent sounds are generated that are synchronized with the movement of the master unit 1, it becomes easier to identify the thief who stole the master unit 1. Due to these effects, the user can find the master unit 1 more reliably and quickly.

[0123] <Embodiment 2> In this embodiment, the processing unit 15 of the master unit 1 dynamically sets the acceleration threshold used for anomaly detection. The configuration of the communication system in this embodiment is the same as the configuration of Embodiment 1 shown in Figure 3.

[0124] Figure 7 is a diagram illustrating the situation (use case) assumed in this embodiment. As shown in Figure 7(a), the user is walking with the main unit 1 in their pants pocket or bag, and wearing the slave unit 3 (for example, headphones) (for example, while listening to music). Next, as shown in Figure 7(b), we assume a situation where a criminal takes advantage of the user's distraction and steals the main unit 1. The situation shown in Figure 7 may hereafter be referred to as Pattern 3 (Theft / Loss Pattern 3).

[0125] Figure 8 shows an example of the change in acceleration detected by the sensor unit 13 of the master unit 1 and the change in signal strength of the slave unit 3 detected by the short-range communication unit 112 of the master unit 1 in pattern 3. Initially, because the user is walking, a certain pattern appears in the acceleration of the master unit 1 corresponding to the walking motion. That is, acceleration with a nearly constant amplitude and a nearly constant period is detected periodically.

[0126] Time point A indicates the point in time when a predetermined time T1 has elapsed since the master unit 1 detected acceleration specific to walking. Time point B indicates the point in time when the perpetrator stole the master unit 1.

[0127] At time point B, the perpetrator takes the master unit 1 from the user's pocket, resulting in a large acceleration being detected. Furthermore, from time point B onward, the perpetrator is walking quickly or jogging away. Therefore, as shown in this figure, up to time point B, regular changes in acceleration characteristic of walking are detected, but from time point B onward, accelerations with larger amplitudes and shorter periods are detected.

[0128] At time point C, the signal strength falls below the first threshold, enabling anomaly detection due to the decrease in signal strength. However, to prevent false detections, the first threshold cannot be set too high, so time point C generally occurs later than time point B. Therefore, especially in pattern 3, it is necessary to use acceleration information to detect abnormal conditions early.

[0129] In this embodiment, after the master unit 1 executes S100 in Figure 5, it does not proceed to S110, but instead executes the process shown in the flowchart in Figure 9. Figure 9 is a flowchart showing the process flow for creating a reference range used to determine an abnormal state.

[0130] In S102, the processing unit 15 of the master unit 1 acquires acceleration information from the sensor unit 13. S102 is the same as S110.

[0131] In S104, the processing unit 15 of the master unit 1 analyzes the waveform of the acceleration sensor, calculates the amplitude and period of acceleration, and records them in the storage unit 17 in correspondence with the time. The processing unit 15 also calculates the rate of change of acceleration (derivative) and records it in the storage unit 17 in correspondence with the time.

[0132] In S106, the processing unit 15 of the master unit 1 refers to the storage unit 17 and determines whether a constant acceleration pattern has persisted for a predetermined time T1 (for example, 1 minute) or longer. Specifically, it is determined that a constant acceleration pattern has persisted if the amplitude, period, and derivative of the acceleration are all within predetermined ranges during the predetermined time T1. If a constant acceleration pattern has persisted (S106: Yes), the process proceeds to S108. If a constant acceleration pattern has not persisted (S106: No), the process in Figure 9 is terminated, and the process proceeds to S120 in Figure 5.

[0133] In S108, the processing unit 15 of the master unit 1 calculates acceleration statistics at a predetermined time T1, and based on these statistics, creates a reference value or reference range and records it in the storage unit 17. Specifically, the processing unit 15 calculates the average value and standard deviation of the amplitude (maximum amplitude per period) at a predetermined time T1, the average value and standard deviation of one period, and the maximum value of the differential coefficient of acceleration as reference values ​​for acceleration statistics. The processing unit 15 may use variance instead of standard deviation. Alternatively, the processing unit 15 may take the absolute value of the differential coefficient of acceleration and calculate its maximum value.

[0134] The processing unit 15 of the master unit 1 then creates a reference value based on these statistics and records it in the storage unit 17. For example, the processing unit 15 may use a predetermined multiple of the average amplitude (e.g., 2 times) as the reference value, or a value obtained by adding a predetermined value to the average amplitude as the reference value, or a predetermined multiple of the average period (e.g., 1.5 times) as the reference value, or a value obtained by adding a predetermined value to the maximum value of the derivative as the reference value. In addition, the processing unit 15 may calculate and record a reference range, not just a reference value.

[0135] For example, the reference range could be defined as the value obtained by adding (A1 + N1 × S1) the average amplitude A1 to N1 times the standard deviation S1 of the amplitude (for example, N1 = 3), and then subtracting (A1 - N1 × S1). In this case, if the amplitude is greater than or equal to (A1 - N1 × S1) and less than or equal to (A1 + N1 × S1), it is determined to be within the reference range; otherwise, it is determined to be outside the reference range (exceeding the reference range).

[0136] Alternatively, for example, the reference range could be defined as the value obtained by adding (P1 + N2 × Q1) the average value of the period P1 to N2 times the standard deviation of the period Q1 (for example, N2 = 2), and subtracting it from the average value of the period Q1 to obtain (P1 - N2 × Q1). In this case, if the period is greater than or equal to (P1 - N2 × Q1) and less than or equal to (P1 + N2 × Q1), it is determined to be within the reference range; otherwise, it is determined to be outside the reference range (exceeding the reference range).

[0137] Alternatively, for example, the reference range could be defined as the value obtained by adding (D1 + N3 × G1) the average value D1 of the maximum value of the derivative for each period at a predetermined time T1, multiplied by N3 (for example, N3 = 2) of the standard deviation G1 of the derivative, and subtracting this value (D1 - N3 × G1). In this case, if the maximum value of the derivative for each period is greater than or equal to (D1 - N3 × G1) and less than or equal to (D1 + N3 × G1), it is determined to be within the reference range; otherwise, it is determined to be outside the reference range (exceeding the reference range).

[0138] From S108, proceed to S120 in Figure 5. In this embodiment, from S120, proceed to S130A (not shown), which corresponds to S130.

[0139] In S130A, the processing unit 15 of the master unit 1 determines whether an abnormal condition has occurred, similar to S130. Specifically, the processing unit 15 of the master unit 1 refers to the storage unit 17 and determines whether the amplitude, period, and derivative of the acceleration have exceeded the reference value or reference range. Specifically, the processing unit 15 determines that an abnormal condition has occurred if at least one of the following conditions is met.

[0140] (Anomaly detection 8) The amplitude of acceleration exceeded the standard value or standard range. (Anomaly detected 9) The acceleration period exceeded the standard value or standard range. (Anomaly detection 10) The differential coefficient of acceleration exceeded the standard value or standard range. The reference value for the acceleration amplitude corresponds to the second threshold value in Embodiment 1, but it is dynamically set.

[0141] For example, in the example shown in Figure 8, the reference value for the acceleration amplitude, dynamically created using the method described above, is set from time A onwards. At time B, the acceleration amplitude exceeds this reference value, thus detecting an abnormal condition. In this way, by appropriately using acceleration information, abnormalities can be detected early.

[0142] Furthermore, the processing unit 15 may determine that an abnormal state exists if any combination of the above-mentioned conditions is met in an AND condition. For example, the processing unit 15 may determine that an abnormal state exists if both (abnormal detection 8) and (abnormal detection 9) are met.

[0143] Furthermore, the process shown in Figure 9 can also be used as the process corresponding to Pattern 1 and Pattern 2. For example, when the master unit 1 is placed on a table or the like and is stationary, in S108, information such as the average amplitude = α (where α is equivalent to the acceleration due to gravity), the average period = infinity (no period), and the maximum value of the derivative = 0 is recorded. The acceleration pattern observed from time A onward in Figure 6 is significantly different from this information, and therefore, in S130A, it is determined to be an abnormal state. In other words, the "constant acceleration pattern" in S106 is a concept that includes a stationary state with acceleration of 0 or acceleration α.

[0144] According to this embodiment, the master unit 1 creates a reference value or reference range based on acceleration statistics when a certain acceleration pattern persists for a predetermined time or longer, and uses the created reference value or reference range to determine an abnormal state. As a result, the master unit 1 can detect an abnormal state at an early stage.

[0145] <Embodiment 3> In this embodiment, similar to Pattern 3 shown in Figure 7(a), we assume a situation where the user is carrying the base unit 1 (for example, in a pocket or bag) and wearing the slave unit 3 (for example, headphones) while walking. However, unlike Pattern 3, instead of a criminal stealing the base unit 1, we assume a situation where the user drops the base unit 1 and continues walking for a while without noticing. The situation assumed in this embodiment is sometimes called Pattern 4 (Theft / Loss Pattern 4). The configuration of the communication system in this embodiment is the same as the configuration of Embodiment 1 shown in Figure 3.

[0146] Figure 10 shows the change in acceleration detected by the sensor unit 13 of the master unit 1 and the change in signal strength of the slave unit 3 detected by the short-range communication unit 112 of the master unit 1 in pattern 4.

[0147] Initially, because the user is walking, a certain pattern appears in the acceleration of the base unit 1, corresponding to the walking motion. That is, an acceleration of approximately constant amplitude and periodicity is detected. Time point A indicates the moment when the base unit 1 falls from the user's pocket or bag and enters a state of free fall. In the free fall state, an acceleration of approximately 0 is detected. Furthermore, the free fall state continues for a predetermined time depending on the height from which it fell. For example, if the base unit 1 falls from a height of 1 meter, the free fall state will continue for approximately 0.45 seconds.

[0148] Time point B indicates the point in time when the master unit 1 collides with the ground or floor, resulting in a large acceleration. At time point B, the acceleration exceeds the second threshold, and the (anomaly detection 4) method enables anomaly detection at time point B.

[0149] At time point C, the signal strength falls below the first threshold, making anomaly detection possible at time point C using method (anomaly detection 1). Furthermore, at time point C, since the master unit 1 is stationary on the ground, the acceleration remains at 0 from time point C onward. Below, the method for generating the acoustic signal will be explained for each of the three anomaly detection methods used.

[0150] [Method 1] As the first method, we will explain the case where (anomaly detection 1) is used, that is, the case where anomalies are detected based on signal strength.

[0151] In this case, steps S100 to S140 in Figure 5 are executed first. However, it is assumed that the acceleration information acquired in S110 is stored in the memory unit 17 for a predetermined time (for example, the most recent minute). In S130, the (anomaly detection 1) method is used, so in the example shown in Figure 10, an anomaly is detected at time C. At time C, the master unit 1 is almost stationary, so S140 is determined to be Yes. From S140:Yes, the process proceeds to S145 in Figure 11. Figure 11 is a flowchart showing part of the processing in the master unit 1.

[0152] In S145, the processing unit 15 of the master unit 1 determines whether the master unit 1 has moved during the most recent predetermined time T3 (for example, 3 seconds). Specifically, the processing unit 15 of the master unit 1 refers to the storage unit 17 and determines that the master unit 1 has moved if an acceleration of a predetermined value or an acceleration exceeding a reference range is recorded during the most recent predetermined time T3. In other words, the processing unit 15 determines that the master unit 1 has moved if a displacement exceeding a predetermined standard is observed during the most recent predetermined time T3. If the master unit 1 has moved (S145: Yes), the process proceeds to S155; if the master unit 1 has not moved (S145: No), the process proceeds to S150.

[0153] S150 is the same as S150 in Embodiment 1, and the processing unit 15 generates an acoustic signal indicating that the master unit 1 is stationary. The processing in Figure 11 ends at S150, and the process proceeds from S150 to S170 in Figure 5. From there on, it is the same as the flowchart in Figure 5.

[0154] In S155, the processing unit 15 of the master unit 1 generates (creates) an acoustic signal indicating that the master unit 1 has come to a stop after moving. Specifically, the processing unit 15 generates the following acoustic signal (acoustic signal 3). After generating a short warning sound (also called a passing sound or transition sound) indicating the movement of the master unit 1, the processing unit 15 generates a sound (sustained sound) with a constant amplitude, similar to (acoustic signal 1). It is preferable that the volume (amplitude) of the warning sound is greater than the volume (amplitude) of the sustained sound so that the warning sound is more noticeable than the sustained sound.

[0155] The warning sound should preferably be a sound that evokes the feeling of a fall, impact, or breakage, and lasts for about 1 to 2 seconds. For example, a sound such as a "whoosh" or "pew" with a continuously decreasing frequency may be used. Alternatively, a sound such as a "crash" or "crack" like glass breaking may be used. An alert sound such as "beep beep beep" may also be used as the warning sound. Furthermore, the processing unit 15 may generate a warning sound according to the acceleration at a predetermined time T3.

[0156] For example, the longer the time the acceleration is observed, the longer the duration of the warning sound may be. Alternatively, the duration of the warning sound may be the same as the time the acceleration is actually observed. Furthermore, the larger the acceleration or the derivative of acceleration, the louder the warning sound may be. Also, the larger the acceleration or the derivative of acceleration, the greater the change in the tone of the warning sound may be. For example, if a sound with a continuously decreasing frequency is used as a warning sound, the larger the acceleration, the greater the range of frequency change may be.

[0157] Furthermore, the processing unit 15 may generate voice announcements such as "You have been hit hard" or "You have fallen" depending on the magnitude and direction of acceleration, and the generated voice announcements may be used as warning sounds. For example, the processing unit 15 may generate a warning sound lasting about 1 to 2 seconds, followed by a sustained sound that maintains a constant amplitude for a predetermined period of time or longer. The sustained sound should preferably have a lower frequency than the warning sound.

[0158] Furthermore, the volume of the sustained sound should be lower than the volume of the warning sound. In other words, the volume of the warning sound should be higher than the volume of the sustained sound. As a result, a sound such as "whoosh, boom" is generated as (acoustic signal 3). The process in Figure 11 ends at S155, and the process proceeds from S155 to S170 in Figure 5. From there on, it is the same as the flowchart in Figure 5.

[0159] By generating such an (acoustic signal 3), the user can intuitively and quickly understand that the master unit 1 has come to a stop after falling or the like.

[0160] [Second method] As a second method, we will explain the case where anomaly detection is performed using (anomaly detection 4), that is, by detecting a large acceleration.

[0161] In this case, the flowchart in Figure 5 or the method in Embodiment 2 is executed. In S130, (anomaly detection 4) or the method in Embodiment 2 is used, so in the example shown in Figure 10, an anomaly is detected at time B when the acceleration exceeds the second threshold, reference value, or reference range. At time B and immediately afterward, the master unit 1 is moving, so it is determined to be No in S140, and (acoustic signal 2) is generated in S160. For example, an intermittent sound (click sound) is generated when the master unit 1 collides with the ground or floor or bounces.

[0162] Subsequently, S170 to S180 are executed. Generally, users cannot issue a notification stop command or an alarm output command in a short time of about 1 to 2 seconds, so S190: No and S220: No are determined, and the process returns to S140 and is repeated. When S140 is executed for the second time or thereafter, the master unit 1 becomes stationary, so S140: Yes is determined, and S150 is executed.

[0163] This generates (acoustic signal 1). In other words, when pattern 4 occurs, a short (acoustic signal 2) is generated, followed by a long (acoustic signal 1). Therefore, the user can intuitively and quickly understand that the master unit 1 has come to a stop after falling or the like.

[0164] [Third Method] As a third method, we will explain the case of detecting a free-fall state. In this case, the process is almost the same as the flowchart in Figure 5, but the following differences are observed.

[0165] In S130B (not shown), which corresponds to S130, the processing unit 15 of the master unit 1 determines whether or not an abnormal condition has occurred. However, a free-fall state is also considered one of the abnormal conditions. In other words, the processing unit 15 performs abnormality detection including the following (abnormality detection 11). (Anomaly detected 11) A free-fall state was detected.

[0166] As described above, since the acceleration becomes almost zero at time A, the processing unit 15 can determine that it is in a free-fall state. For example, the processing unit 15 of the master unit 1 may determine that it is in a free-fall state if the acceleration is below a predetermined value for a predetermined time or longer. This predetermined value should preferably be a value that is sufficiently smaller than the acceleration due to gravity. The predetermined time can be, for example, 0.1 seconds. From S130B, the process proceeds to S132 in the flowchart of Figure 12, not to S140. Figure 12 is a flowchart showing part of the processing in the master unit 1.

[0167] In S132, the processing unit 15 of the master unit 1 determines whether or not it is in a free-fall state. Specifically, the processing unit 15 can determine the free-fall state using the method described above. If it is in a free-fall state (S132: Yes), proceed to S134; if it is not in a free-fall state (S132: No), terminate the process shown in Figure 12 and proceed to S140. The process thereafter is the same as the flowchart in Figure 5.

[0168] In S134, the processing unit 15 of the master unit 1 generates an acoustic signal indicating a free-fall state. Specifically, it should generate the (acoustic signal 3) described above. For example, it is good to use a sound such as "whoosh" or "pew" with a continuously decreasing frequency to evoke the image of falling. The process in Figure 12 ends in S134 and proceeds to S170. The process after that is the same as the flowchart in Figure 5.

[0169] Therefore, (acoustic signal 3) is generated between time point A and time point B, (acoustic signal 2) is generated between time point B and time point C, and (acoustic signal 1) is generated from time point C onward. For example, sounds such as "whoosh, beep beep, boom" are generated. As a result, the user can understand the movement status of the master unit 1 in a more intuitive and detailed manner.

[0170] Furthermore, in the first method, the warning sound is generated with a slight delay (a small time lag) after the actual fall or impact occurs, whereas in the third method, the warning sound is generated almost in real time (without any time lag). Therefore, with the third method, the user can recognize the fall of the main unit 1 earlier. In other words, using the third method, it may be possible in some cases for the user to recognize the fall and take action (such as catching it with their hand or placing their foot between the main unit 1 and the ground to mitigate the impact) before the main unit 1 hits the ground or floor.

[0171] According to this embodiment, even if the user drops the main unit 1 while walking, the system can quickly notify the user that an abnormality has occurred, thereby preventing the loss or damage of the main unit 1.

[0172] <Embodiment 4> In previous embodiments, an acoustic signal indicating the movement status of the master unit 1 was generated. In this embodiment, in addition to that, voice information indicating the status of the master unit 1 is generated and transmitted to the slave unit 3. The configuration of the communication system in this embodiment is the same as the configuration of Embodiment 1 shown in Figure 3.

[0173] In this embodiment, the processing unit 15 (generation unit) of the master unit 1 further generates voice information indicating the distance to the slave unit 3, calculated based on the location information of the master unit 1 or the signal strength of the short-range communication unit 112 (receiving unit). The short-range communication unit 112 (transmission unit) of the master unit 1 transmits the acoustic signal and voice information to the slave unit 3.

[0174] In this embodiment, after executing steps S100 to S170 in the flowchart of Figure 5, the processing in the flowchart of Figure 13 is executed. That is, the process proceeds from S170 to S172 in Figure 13. Figure 13 is a flowchart showing the processing related to the generation of voice information in the master unit 1.

[0175] In S172, the processing unit 15 of the master unit 1 determines whether or not it has transmitted an acoustic signal for a predetermined time or longer. That is, the processing unit 15 determines whether or not it has transmitted any of the above-mentioned (acoustic signal 1) to (acoustic signal 3) for a predetermined time or longer. For example, the predetermined time may be 3 seconds. Alternatively, the criterion may be "a predetermined number of times" instead of "a predetermined time". For example, if steps S140 to S220 are repeatedly executed with a 1-second cycle, the processing unit 15 of the master unit 1 may determine whether or not it has transmitted an acoustic signal a predetermined number of times (e.g., 3 times) or more.

[0176] In this embodiment, a variable indicating the transmission time (or number of transmissions) of the acoustic signal is stored in the storage unit 17, and this variable is initialized to 0 when the process shown in Figure 5 is started. The unit of the variable is arbitrary; for example, it may be in seconds or milliseconds.

[0177] The following explanation uses a variable indicating the transmission time as an example, but the same process can be followed when using a variable indicating the number of transmissions. If the acoustic signal has been transmitted for a predetermined time or longer (S172:Yes), proceed to S174; if the acoustic signal has not been transmitted for a predetermined time or longer (S172:No), proceed to S180.

[0178] In S174, the processing unit 15 of the master unit 1 refers to the storage unit 17 and resets the variable indicating the transmission time of the acoustic signal. In other words, the processing unit 15 sets that variable to 0.

[0179] In S176, the processing unit 15 of the master unit 1 generates (creates) audio information (such as a voice announcement) indicating the location of the master unit 1. For example, the processing unit 15 can create the audio information using speech synthesis technology that reads text information aloud. Examples of audio information are shown below, but are not limited to these.

[0180] (Voice Information 1) Based on information acquired from the position detection unit 12 of the master unit 1, the voice reads out the direction and distance relative to a predetermined point (for example, a certain location inside a building). For example, voice information such as "Main unit 1 is located 10 meters north of the reference location" is generated.

[0181] (Voice Information 2) Voice reading of (latitude, longitude) based on information acquired from the position detection unit 12 of the master unit 1. For example, voice information such as "Main unit 1 is located at N1 degrees N2 minutes N3 seconds north latitude and E1 degrees E2 minutes E3 seconds east longitude" will be generated. Note that units finer than seconds may also be used.

[0182] (Voice Information 3) Voice reading of the location information of base unit 1 converted into address, building name, street name, room name, etc. For example, voice information such as "The master unit 1 is located at 1-2-3 B town, A city, inside Building C" is generated. In this case, the memory unit 17 of the master unit 1 stores data (map data) that shows the correspondence between latitude and longitude and address, building name, and street name. Alternatively, the long-distance communication unit 111 of the master unit 1 may acquire such map data from an external server or the like as appropriate.

[0183] Furthermore, in environments where the base station 1 can use an indoor positioning system, more detailed location information may be included, such as, "Base station 1 is located in front of conference room E, 3 meters to the left after leaving conference room D and walking down the corridor." The processing unit 15 of base station 1 creates voice information based on the map data stored in the storage unit 17 or map data acquired from an external source, and the location information detected by the location detection unit 12.

[0184] (Audio Information 4) Audio reading of the relative position based on the position of the master unit 1 when an abnormal condition was determined in S130. For example, voice information such as "Main unit 1 is located 5 meters southeast of the location where the abnormality occurred" is generated.

[0185] (Audio information 5) Audio reading out the direction and speed of movement. For example, voice information such as "Main unit 1 is moving eastward at a speed of 2 meters per second" is generated.

[0186] (Audio information 6) Audio reading of information indicating ambient illuminance. If the sensor unit 13 of the master unit 1 is equipped with an illuminance measurement function, voice information such as "The master unit 1 is in a bright (or dark) place" will be generated. This makes it easier for the user to determine whether the perpetrator has the master unit 1 in their bag or pocket, or is holding it in their hand, making it easier to identify the perpetrator.

[0187] (Audio information 7) Ambient sounds (audio picked up by the audio input section 181 of the master unit 1). This makes it easier to identify the perpetrator because conversations and ambient sounds of people around the master unit 1 can be heard. Alternatively, the processing unit 15 of the master unit 1 may have the camera unit (not shown) take pictures of the area around the master unit 1, generate audio information such as "Master unit 1 is recording its surroundings," and transmit it to the slave unit 3. The processing unit 15 may also control the audio output unit 182 to output audio information such as "Recording is currently in progress" along with an alarm sound from the master unit 1.

[0188] (Voice information 8) Voice reading out the distance between base unit 1 and slave unit 3. The processing unit 15 of the master unit 1 calculates the distance based on the signal strength of the radio waves from the slave unit 3 received by the short-range communication unit 112 and the transmission output information of the slave unit 3. For example, voice information such as "Master unit 1 is located 10 meters away from slave unit 3 (you)" is generated.

[0189] (Audio information 9) Audio reading out acceleration information. For example, voice information such as "A strong vertical acceleration is being applied to base unit 1 with a 1-second cycle" is generated.

[0190] The processing unit 15 of the master unit 1 may combine these voice pieces as it sees fit. For example, the processing unit 15 may combine (voice piece 5) and (voice piece 8) to generate voice piece such as, "Master unit 1 is moving eastward at a speed of 1 meter per second, 5 meters away from slave unit 3 (you)."

[0191] Let's return to the explanation of the flowchart in Figure 13. In S178, the processing unit 15 of the master unit 1 transmits audio information indicating the status of the master unit 1 to the slave unit 3 via the short-range communication unit 112. The processing unit 15 of the master unit 1 also initializes (resets) a variable that stores the transmission time or number of transmissions of the acoustic signal stored in the storage unit 17. In other words, the processing unit 15 sets the value of that variable to 0. The process in Figure 13 ends at S178, and the process proceeds from S178 to S190 in Figure 5. From there on, it is the same as the flowchart in Figure 5.

[0192] S180 is the same as S180 in Figure 5. In other words, the processing unit 15 of the master unit 1 causes the master unit 1's short-range communication unit 112 to transmit an acoustic signal (notification sound).

[0193] In S182, the processing unit 15 of the master unit 1 refers to the storage unit 17 and updates the variable indicating the transmission time of the acoustic signal. That is, the processing unit 15 increments the variable by the duration of the acoustic signal transmitted in S180. For example, if the acoustic signal transmitted in S180 is 1 second, the processing unit 15 increases the value of the variable by 1 second. If a variable indicating the number of acoustic signal transmissions is used, the value of that variable should be increased by 1. The process in Figure 13 ends in S182, and the process proceeds from S182 to S190 in Figure 5. From there on, it is the same as the flowchart in Figure 5.

[0194] In the above explanation, the processing unit 15 of the master unit 1 created the voice information, but this is not the only way. For example, in S178, the processing unit 15 of the master unit 1 may transmit text information indicating the status of the master unit 1 to the slave unit 3 via the short-range communication unit 112. The processing unit 35 of the slave unit 3 may receive this text information via the short-range communication unit 312, convert it into voice using speech synthesis technology, and then output the voice from the voice output unit 382.

[0195] According to this embodiment, in addition to an acoustic signal indicating the movement status of the master unit 1, voice information indicating the status of the master unit 1 is transmitted to the slave unit 3. As a result, the user can easily understand the location, direction of movement, speed of movement, and surrounding conditions of the master unit 1. This makes it easier to identify the perpetrator and find the master unit 1.

[0196] <Embodiment 5> In this embodiment, more detailed voice information is generated. Figure 14 is a diagram of the communication system configuration in this embodiment. As shown in Figure 14, in this embodiment, similar to the position detection unit 12 and sensor unit 13 of the master unit 1, the slave unit 3 also has a position detection unit 32 and a sensor unit 33.

[0197] The short-range communication unit 112 (receiving unit) of the master unit 1 receives a signal containing location information and direction information indicating the orientation of the slave unit 3. The processing unit 15 (generating unit) of the master unit 1 generates audio information indicating the relative position of the master unit 1 based on the location information of the master unit 1 and the location and direction information of the slave unit 3. The short-range communication unit 112 (transmitting unit) of the master unit 1 transmits the acoustic signal and audio information to the slave unit 3.

[0198] The position detection unit 32 of the slave unit 3 is the same as the position detection unit 12 of the master unit 1, and detects the position information of the slave unit 3 using a GNSS system, mobile phone base station information, wireless LAN access point information, indoor positioning system, etc. The position information may be (latitude, longitude), or it may be the direction and distance based on a predetermined point (for example, a place inside a building).

[0199] The sensor unit 33 of the slave unit 3 is equipped with at least a geomagnetic sensor (direction sensor). Therefore, the sensor unit 33 can detect which direction the user wearing the slave unit 3 is facing. The sensor unit 33 may also be equipped with an acceleration sensor, a gyroscope, or the like.

[0200] The other configurations are the same as those of Embodiment 1 shown in Figure 3. The short-range communication unit 312 of the slave unit 3 transmits location information and direction information of the slave unit 3 at any time. For example, the short-range communication unit 312 may transmit when the location information or direction information of the slave unit 3 changes, or it may transmit at a predetermined interval. The short-range communication unit 112 of the master unit 1 receives location information and direction information of the slave unit 3 at any time.

[0201] The processing of the master unit 1 in this embodiment follows the same flow as in Embodiment 4. That is, it executes the processes shown in the flowcharts in Figures 5 and 13. However, it differs from Embodiment 4 in the following respects.

[0202] In S130, the processing unit 15 of the master unit 1 may use any of the following methods in addition to the abnormality detection method described in the previous embodiments.

[0203] (Anomaly detection 12) The distance calculated based on the location information of the master unit 1 and the location information of the slave unit 3 has exceeded a predetermined value. The distance between the two can be calculated using Hubeni's formula or similar methods. This method generally provides higher accuracy than the distance calculated based on the signal strength used in (anomaly detection 3) and the transmission output of the slave unit 3, allowing the processing unit 15 to detect abnormal conditions with greater precision.

[0204] (Anomaly detection 13) The direction (orientation) of the master unit 1 relative to the slave unit 3 has exceeded a predetermined standard. The processing unit 15 of the master unit 1 calculates the direction of the master unit 1 relative to the slave unit 3 based on the location information of the master unit 1 and the location information of the slave unit 3. For example, if a predetermined condition is set that the master unit 1 is located within the range from north (0 degrees) to east (90 degrees) of the slave unit 3, the processing unit 15 determines that an abnormal state is occurring if the direction of the master unit 1 is south (180 degrees) of the slave unit 3.

[0205] (Anomaly detection 14) The acceleration change of master unit 1 and the acceleration change of slave unit 3 are significantly different. For example, if similar accelerations are observed at almost the same time in both the master unit 1 and the slave unit 3, the processing unit 15 will not determine it to be an abnormal state, as it is highly likely that the user of slave unit 3 is carrying master unit 1. On the other hand, if the amplitude and period of acceleration differ significantly between master unit 1 and slave unit 3, the processing unit 15 will determine it to be an abnormal state.

[0206] After executing S174, S175 (not shown) is executed. In S175, the processing unit 15 of the master unit 1 calculates the direction (direction) and distance of the master unit 1 relative to the user of the slave unit 3 (facing the user).

[0207] Figure 15 schematically shows the positional relationship between the user with the slave unit 3 attached and the master unit 1. Assume the user is facing direction a in the figure. In this case, the master unit 1 can obtain the following information by using the position information of the master unit 1, the position information of the slave unit 3, and the information from the geomagnetic sensor.

[0208] The user of handset 3 is facing direction a. In the example in Figure 15, direction a is southwest (225 degrees clockwise from north). • The master unit 1 is located 10 meters northeast of the slave unit 3. • The direction of the master unit 1 is offset by 180 degrees from direction a, so the master unit 1 is located 10 meters behind the user.

[0209] Furthermore, the geomagnetic sensor in sub-unit 3 has been calibrated, and the rotation angle can be obtained with respect to magnetic north. However, for more accurate calculation of relative direction, it is desirable to calibrate sub-unit 3 so that the rotation angle can be obtained with respect to true north rather than magnetic north.

[0210] From S175, the process proceeds to S176A (not shown), which corresponds to S176. In S176A, the processing unit 15 of the master unit 1 generates (voice information 10) indicating the direction and distance calculated in S175.

[0211] (Voice Information 10) For example, in the situation shown in Figure 15, voice information such as "The base unit 1 is located approximately 10 meters behind you" is generated. This makes it possible to provide the user with more intuitive and easy-to-understand voice information. Of course, various other voice information as described in Embodiment 4 may also be added. The process proceeds from S176A to S178.

[0212] According to this embodiment, the location information of the master unit 1 as seen from the user wearing the slave unit 3 can be provided in a way that is intuitively easy for the user to understand, so the user can find the master unit 1 more easily.

[0213] <Embodiment 6> Similar to Embodiment 5, if the slave unit 3 is also equipped with a position detection unit 32 and a sensor unit 33, it is also possible to search for the slave unit 3 from the master unit 1. The processing unit 15 of the master unit 1 acquires position information, direction information, acceleration information, etc. of the slave unit 3 via the short-range communication unit 112, and processes the information by replacing the movement status (movement state) and position information of the master unit 1 in Embodiments 1 to 5 with the movement status and position information of the slave unit 3.

[0214] For example, the processing unit 15 of the master unit 1 generates an acoustic signal indicating the movement status of the slave unit 3 (indicating whether it is stationary or moving). Alternatively, the processing unit 15 of the master unit 1 may generate audio information indicating the direction and distance of the slave unit 3 relative to the master unit 1, similar to Figure 15.

[0215] The processing unit 15 of the master unit 1 outputs the generated acoustic signals and audio information to the audio output unit 182 of the master unit 1. Furthermore, since the master unit 1 is equipped with a display unit 16, the relative positional relationship (distance) and absolute positional information (latitude, longitude) of the master unit 1 and the slave unit 3 may be displayed on the display unit 16, as shown in Figure 15. For example, the display unit 16 may display icons representing the master unit 1 and the slave unit 3 on a map.

[0216] Furthermore, the display format of the icon for the slave unit 3 (e.g., color, shape, size, etc.) may be changed depending on the movement status of the slave unit 3 (e.g., whether it is stationary or moving). For example, the display unit 16 may display a still image icon when the slave unit 3 is stationary, and display the icon as if it is vibrating or display an animated icon that changes over time when the slave unit 3 is moving.

[0217] Furthermore, if the master unit 1 has a vibration function, the master unit 1 may be vibrated when the slave unit 3 is moving. In this case, the master unit 1 may also be vibrated in sync with the timing of the displacement of the slave unit 3 (for example, at the timing when the displacement of the slave unit 3 is maximum). By providing such displays and notifications, users can search for the slave unit 3 more intuitively. In addition, by combining the output of acoustic signals and voice information from the audio output unit 182 with the display on the display unit 16, users can understand the location and status of the slave unit 3 even more intuitively and easily.

[0218] Furthermore, the processing unit 35 of the slave unit 3 may acquire position information, acceleration information, direction information, etc., of the master unit 1 via the short-range communication unit 312, create an acoustic signal indicating the movement status of the master unit 1, and voice information indicating the position of the master unit 1 relative to the slave unit 3, and output them from the voice output unit 382. Alternatively, the processing unit 35 of the slave unit 3 may create an acoustic signal indicating the movement status of the slave unit 3 and voice information indicating the position of the slave unit 3 relative to the master unit 1 based on the information acquired from the position detection unit 32 and the sensor unit 33, and transmit them to the master unit 1 via the short-range communication unit 312. The processing unit 15 of the master unit 1 may output the acoustic signals and voice information received via the short-range communication unit 112 from the voice output unit 182.

[0219] Each of the functional components of the terminal device 100, master unit 1, and slave unit 3 described above may be implemented by hardware (e.g., hardwired electronic circuits) or by a combination of hardware and software (e.g., a combination of an electronic circuit and a program that controls it). For example, this disclosure can also be implemented by having a CPU execute a computer program to perform any processing.

[0220] The program, when loaded into a computer, includes a set of instructions (or software code) for causing the computer to perform one or more of the functions described in the embodiments. The program may be stored in various types of non-transitory computer-readable medium or tangible storage medium. Examples, but not limited to, include non-transitory computer-readable medium or tangible storage medium, such as RAM (Random-Access Memory), ROM (Read-Only Memory), flash memory, SSD (Solid-State Drive) or other memory technologies, CD-ROM, DVD (Digital Versatile Disc), Blu-ray® disc or other optical disc storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage devices. The program may also be transmitted over various types of transient computer-readable medium or communication medium. Examples, but not limited to, include transient computer-readable medium or communication medium, such as electrical, optical, acoustic or other forms of propagating signals.

[0221] This disclosure is not limited to the embodiments described above, and can be modified as appropriate without departing from the spirit of the invention. Furthermore, the embodiments described above can be combined in any way. [Explanation of Symbols]

[0222] 1. Master unit 3. Handset 11 Communications Department 12 Position detection unit 13 Sensor section 14 Light-emitting part 15 Processing Unit 16 Display section 17 Memory section 18. Audio section 32 Position detection unit 33 Sensor section 35 Processing Unit 37 Memory section 38. Audio section 39 Control section 100 terminal devices 101 Receiving Unit 102 Sensor section 103 Detection unit 104 Generation part 105 Transmitter 111 Long-Distance Communications Department 112 Near Field Communication Department 181 Voice Input Section 182 Audio Output Section 312 Near Field Communication Department 381 Voice Input Section 382 Audio Output Section

Claims

1. A receiving unit that receives signals transmitted from another device equipped with an audio output unit, This device includes a sensor unit that outputs displacement information indicating a change in position or orientation, A detection unit that detects an abnormal state based on the signal strength of the receiving unit or the displacement information, When an abnormal condition is detected by the detection unit, a generation unit generates an acoustic signal based on the displacement information, A transmitting unit that transmits the acoustic signal generated by the generation unit to the other device, Equipped with, The generation unit determines the movement state of the device based on the displacement information and generates a plurality of acoustic signals, each having at least one of the amplitude and frequency of the acoustic signal, corresponding to each of the plurality of movement states. Terminal device.

2. The generation unit generates a first acoustic signal when the displacement information is within a predetermined reference range, and generates a second acoustic signal when the displacement information exceeds a predetermined reference range. The second acoustic signal exhibits a greater temporal variation in at least one of its amplitude and frequency compared to the first acoustic signal. The terminal device according to claim 1.

3. The generation unit generates a first acoustic signal with constant amplitude and frequency when the displacement information is within a predetermined reference range, and when the displacement information exceeds a predetermined reference range, it determines the timing for changing at least one of the amplitude and frequency according to the displacement information and generates a second acoustic signal in which at least one of the amplitude and frequency changes. The terminal device according to claim 1.

4. This device further includes a position detection unit that detects the position information of the device, The receiving unit receives a signal that includes the position information of the other device and the orientation information of the other device. The generation unit further generates audio information indicating the relative position of the device based on the position information of the device, the position information of the other device, and the orientation information, with respect to the position and orientation of the other device. The transmitting unit transmits the acoustic signal and the voice information to the other device. The terminal device according to any one of claims 1 to 3.

5. A receiving step of receiving a signal transmitted from another device equipped with an audio output unit, An output step that outputs displacement information indicating a change in the position or orientation of this device, A detection step that detects an abnormal state based on the signal strength of the receiving step or the displacement information, If an abnormal condition is detected in the above detection step, a generation step is performed to generate an acoustic signal based on the displacement information, A transmission step of transmitting the acoustic signal generated in the generation step to the other device, A program that causes a computer to execute, In the generation step, the movement state of the device is determined based on the displacement information, and a plurality of acoustic signals are generated corresponding to each of the plurality of movement states, each having at least one of the amplitude and frequency of the acoustic signal. program.

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