Presentation system

Abstract

To present a proximity state of a user to a blockade area even under mist, sand cloud or other bad conditions.SOLUTION: An acceleration acquisition unit 211 acquires acceleration information of a local terminal from an acceleration sensor 241. A rotation angle acquisition unit 212 acquires rotation angle information of the local terminal from a gyro sensor 242. A signal acquisition unit 213 acquires a radio wave signal received by a reception unit. A bearing identification unit 214 identifies the bearing of a mobile terminal 2 relative to an estimation device 1 on the basis of the signal acquired by the signal acquisition unit 213. A determination unit 215 grasps a proximity state of a user U carrying the mobile terminal 2 to a blockade area R on the basis of information pertaining to acceleration, rotation angle, and bearing and determines whether the user U is in danger. A presentation control unit 216 warns the user U of danger by controlling the presentation unit 25 when it is determined by the determination unit 215 on the basis of the proximity state that the user U is in danger.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention relates to a technology for a presentation system that presents a user's approach to a closed area. [Background technology]

[0002] In workplaces such as civil engineering construction sites, for safety reasons, areas (hereinafter referred to as "closed areas") are sometimes provided that are closed off to prevent users such as workers from approaching. In workplaces where closed areas are provided, it is desirable to have a presentation system that presents warnings or the like in response to the situation in which a user approaches the closed area (hereinafter referred to as the approach situation). For example, the following Patent Documents 1-2 are technologies for monitoring the user's position (direction, distance) and performing control in response to the monitoring results.

[0003] Patent Document 1 discloses an eyeglass-type display device that is worn on a user's head and includes a display that is visible to the user, and an operation content receiving unit that receives operation content from the user, in which the display displays an image showing the positioning information of a target for positioning by a position measuring device using laser light and the positional relationship between the target and a predetermined planned installation position, and multiple coordinate systems are provided for the image display, and the operation content receiving unit is configured to receive designation of one of the multiple coordinate systems by the user.

[0004] Patent document 2 discloses a method for determining a position of a mobile device based on a first position estimate made using a first position system, the method including the steps of obtaining an initial estimate of the position of the mobile device based on a second position estimate that is coarser than the first position estimate, using the initial estimate to select a subset of wireless reference nodes of the first network that are within a defined vicinity of the position of the mobile device, and selectively providing respective assistance data for each of the subset of wireless reference nodes from a database of respective assistance data for each of the wireless reference nodes stored on a server of the first position system to a position determination module on the mobile device, in order for the position determination module of the mobile device to calculate a finer estimate of the position of the mobile device. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2020-169855 A [Patent Document 2] Special Publication No. 2018-512571 Summary of the Invention [Problem to be solved by the invention]

[0006] The technology described in Patent Document 1 uses laser light to determine the position of the user's head, but the detection accuracy of such optical detection methods is significantly affected by fog, dust, and the like. The technology described in Patent Document 2 uses an alternative coarse positioning system that takes into consideration privacy when identifying an individual's location, but it cannot protect the user because it does not monitor the user's approach to the sealed-off area, such as whether the user's field of vision includes the sealed-off area, or whether the user's movement direction and speed are within a specified range relative to the sealed-off area.

[0007] One of the objects of the present invention is to present the user's approach to a closed area even under adverse conditions such as fog or dust. [Means for solving the problem]

[0008] The present invention provides, as a first aspect, a presentation system comprising an estimation device present in a field having a sealed-off area, a mobile terminal carried by a user moving through the field, and a presentation device, wherein the estimation device generates user information for the mobile terminal by transmitting and receiving radio waves with the mobile terminal, the mobile terminal receives the user information, and causes the presentation device to present the user's approach to the sealed-off area based on the user information.

[0009] According to the presentation system of the first aspect, it is possible to present the user's approach to the sealed off area even under adverse conditions such as fog or dust.

[0010] In the presentation system of the first aspect, a configuration may be adopted as a second aspect in which the mobile terminal or the presentation device warns the user when it determines that the user is in danger based on the approach situation.

[0011] According to the presentation system of the second aspect, when it is determined that the user is in danger, it is possible to issue a warning to the user.

[0012] In the presentation system of the first aspect, a configuration in which the mobile terminal includes the presentation device may be adopted as a third aspect.

[0013] According to the presentation system of the third aspect, the presentation device provided in the mobile terminal carried by the user can directly present the approach status to the blocked area to the user.

[0014] In the presentation system of the first aspect, a configuration may be adopted as a fourth aspect, in which the user information includes information on the position, movement direction, and field of view of the user.

[0015] According to the presentation system of the fourth aspect, the user's approach to the sealed off area can be presented based on the user's position, movement direction, and field of view.

[0016] In the presentation system of the first aspect, a configuration may be adopted as a fifth aspect in which the mobile terminal transmits identification information identifying the terminal itself via the radio waves, and the estimation device transmits the user information to the mobile terminal indicated by the identification information contained in the received radio waves.

[0017] According to the presentation system of the fifth aspect, the approach to a closed area can be presented individually to each of a plurality of users.

[0018] In the presentation system of the fourth aspect, a sixth aspect may be adopted in which the mobile terminal and the estimation device have a plurality of receivers arranged at a predetermined interval, one of which transmits the radio waves and the other receives the radio waves, and the location of the user is estimated based on a phase difference or intensity difference of the radio waves received by each of the plurality of receivers, and the user information including information on the location is generated.

[0019] According to the presentation system of the sixth aspect, the user's position can be estimated by a plurality of receivers to generate user information. [Brief description of the drawings]

[0020] [Figure 1] 1 is a diagram showing an example of the overall configuration of a presentation system 9 according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram showing an example of the appearance of a mobile terminal 2. [Diagram 3] FIG. 2 shows an example of the configuration of a mobile terminal 2. [Figure 4] FIG. 1 is a diagram showing an example of the configuration of an estimation device 1. [Diagram 5] 4 is a diagram showing an example of reception angles of radio waves received by a receiving unit 132. FIG. [Figure 6] 4A and 4B are diagrams showing examples of transmission angles of radio waves transmitted by a transmission unit 131. [Figure 7] FIG. 2 is a diagram showing an example of a user's field of view identified by a mobile terminal 2. [Figure 8] FIG. 2 is a diagram showing an example of the functional configuration of the estimation device 1. [Figure 9] FIG. 2 is a diagram showing an example of the functional configuration of a mobile terminal 2. [Figure 10] FIG. 4 is a flowchart showing an example of the operation flow of the estimation device 1. [Figure 11] 4 is a flowchart showing an example of the operation flow of the mobile terminal 2. [Figure 12] FIG. 13 is a diagram showing an example of a presentation device 3 according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] <Embodiment> <Overall configuration of presentation system> In the figures shown below, the space in which each component is placed is represented as an xyz right-handed coordinate space. Among the coordinate symbols shown in the figures, a dot in a circle represents an arrow pointing from the back of the page to the front. The direction along the x-axis in space is called the x-axis direction. In addition, within the x-axis direction, the direction in which the x component increases is called the +x direction, and the direction in which the x component decreases is called the -x direction. For the y and z components, the y-axis direction, +y direction, -y direction, z-axis direction, +z direction, and -z direction are defined according to the above definitions. In the figures below, the -z direction is the direction in which gravity acts, that is, the vertical downward direction.

[0022] 1 is a diagram showing an example of the overall configuration of a presentation system 9 according to an embodiment of the present invention. This presentation system 9 is a system that presents a situation (approach situation) in which a user U moving through a place G, such as a construction site, approaches a sealed-off area R. The place G is a predetermined area on the ground surface parallel to the xy plane.

[0023] The presentation system 9 shown in Fig. 1 includes an estimation device 1 and a mobile terminal 2. The estimation device 1 in Fig. 1 is installed in a sealed-off area R. Note that the estimation device 1 does not have to be installed in the sealed-off area R as long as the location of the sealed-off area R is identified. The mobile terminal 2 is a terminal device possessed by each of multiple users U.

[0024] <External appearance of mobile terminal> Fig. 2 is a diagram showing an example of the external appearance of the mobile terminal 2. The mobile terminal 2 shown in Fig. 2 is a glasses-type wearable device worn on the head by a user U. This mobile terminal 2 is composed of, for example, a lens 201, a rim 202, a bridge 203, and a temple 204, and various components described below are held inside the temple 204.

[0025] For example, the lenses 201 are transparent members that are placed in front of both eyes of the user U and transmit visible light. The rims 202 are support members that fix the two lenses 201, one on the left and one on the right. The bridge 203 is a support member that connects the two rims 202, one on the left and one on the right, at the center, and is placed on the nose of the user U. The temples 204 are support members that are placed on the left and right ears of the user U and support the entire mobile terminal 2.

[0026] <Mobile terminal configuration> Fig. 3 is a diagram showing an example of the configuration of the mobile terminal 2. As shown in Fig. 3, the mobile terminal 2 has, for example, a processor 21, a memory 22, a controller 23, a sensor 24, and a presentation unit 25 as components inside the temple 204 described above. The mobile terminal 2 also has a transmission unit 231 and a reception unit 232 controlled by the controller 23. The sensor 24 of the mobile terminal 2 also has an acceleration sensor 241 and a gyro sensor 242.

[0027] The memory 22 is a storage means for storing an operating system, various programs, data, etc., which are loaded into the processor 21. The memory 22 includes a random access memory (RAM) or a read only memory (ROM). The memory 22 may include a solid state drive, a hard disk drive, etc.

[0028] The processor 21 reads and executes a computer program (hereinafter simply referred to as a program) stored in the memory 22 to control each part of the mobile terminal 2. The processor 21 is, for example, a CPU (Central Processing Unit).

[0029] The controller 23 is a control device that controls the transmitting unit 231 and the receiving unit 232. The transmitting unit 231 is a communication circuit that transmits radio waves. The receiving unit 232 is a communication circuit that receives radio waves. The transmitting unit 231 and the receiving unit 232 may share an antenna portion that transmits and receives radio waves. The mobile terminal 2 may include at least one of the transmitting unit 231 and the receiving unit 232 in multiple units.

[0030] The sensor 24 is a group of devices that sense the motion state (movement direction, movement speed, attitude, etc.) of the mobile terminal 2. The acceleration sensor 241 senses the acceleration of the mobile terminal 2. The acceleration sensor 241 may be of a piezoelectric type, a servo type, a strain gauge type, a semiconductor type, etc. For example, the processor 21 measures the movement distance and movement direction of the mobile terminal 2 by integrating the acceleration sensed by the acceleration sensor 241.

[0031] The gyro sensor 242 senses the angular velocity of the mobile terminal 2. The gyro sensor 242 may be a vibration sensor using a piezoelectric method, a capacitance method, or the like, or may be an optical or mechanical sensor. The processor 21 measures the attitude and direction of the mobile terminal 2 by integrating the angular velocity sensed by the gyro sensor 242. For example, by storing the directions of the lens 201, bridge 203, and the like described above in the memory 22 in advance, the processor 21 can use the sensing result of the gyro sensor 242 to generate information on the field of view of the user U wearing the mobile terminal 2.

[0032] The presentation unit 25 displays an image to the user U wearing the mobile terminal 2 under the control of the processor 21. The presentation unit 25 may have, for example, a liquid crystal projector that projects an image onto the above-mentioned lens 201, or may have a projector that projects laser light directly onto the retina of the user U to show the image. It is desirable for the presentation unit 25 to display a transparent image superimposed on the scenery in the field of view that the user U actually sees through the lens 201, without blocking the field of view.

[0033] 3 is a configuration included in the mobile terminal 2, and is a presentation device that presents information under the control of the processor 21 of the mobile terminal 2. In other words, the mobile terminal 2 is an example of a mobile terminal equipped with a presentation device.

[0034] This presentation system 9, which has a mobile terminal 2 equipped with a presentation unit 25 and an estimation device 1, is an example of a presentation system that has an estimation device present in a field having a sealed area, a mobile terminal carried by a user moving around the field, and a presentation device.

[0035] <Configuration of the estimation device> Fig. 4 is a diagram showing an example of the configuration of the estimation device 1. The estimation device 1 is a device that estimates the approach situation of a user U wearing (carrying) a mobile terminal 2 to a sealed area R. The estimation device 1 shown in Fig. 4 has a processor 11, a memory 12, and a controller 13. The estimation device 1 also has a transmitting unit 131 and a receiving unit 132 controlled by the controller 13.

[0036] The memory 12 is a storage means for storing an operating system, various programs, data, etc., which are loaded into the processor 11. The memory 12 includes a RAM or a ROM. The memory 12 may include a solid state drive, a hard disk drive, etc.

[0037] The processor 11 reads out and executes a program stored in the memory 12 to control each part of the estimation device 1. The processor 11 is, for example, a CPU.

[0038] The controller 13 is a control device that controls the transmitting unit 131 and the receiving unit 132. The transmitting unit 131 is a communication circuit that transmits radio waves. The receiving unit 132 is a communication circuit that receives radio waves. The transmitting unit 131 and the receiving unit 132 may share an antenna portion that transmits and receives radio waves. The estimation device 1 may include at least one of the transmitting unit 131 and the receiving unit 132 in multiple units.

[0039] The transmitting unit 131 transmits radio waves to the receiving unit 232 of the mobile terminal 2. Furthermore, the receiving unit 132 receives the radio waves transmitted by the transmitting unit 231 of the mobile terminal 2. The transmitting unit 131 and the receiving unit 132 may have a function of connecting with the transmitting unit 231 or the receiving unit 232 of the mobile terminal 2 in a method conforming to IEEE802.15, such as Bluetooth (registered trademark). Furthermore, the transmitting unit 131 and the receiving unit 132 may be a line using, for example, LPWA (Low Power Wide Area).

[0040] <Radio wave reception angle> FIG. 5 is a diagram showing an example of the receiving angle of the radio wave received by the receiving unit 132. As shown in FIG. 5, the estimation device 1 has a plurality of receiving units 132 arranged at a predetermined interval, for example. That is, the plurality of receiving units 132 are so-called array antennas. The predetermined intervals may all be constant intervals, or may be different as long as they are known. These plurality of receiving units 132 receive the radio wave transmitted by the transmitting unit 231 of the mobile terminal 2 at their respective positions. The radio wave is transmitted by the transmitting unit 231 at a phase determined in advance. The radio wave is a sine wave signal, a chirp signal, a pulse signal, or the like.

[0041] The processor 11 of the estimation device 1 estimates the reception angle θa (also called the arrival angle or incident angle) of the radio wave based on, for example, the phase difference of the radio wave received by each of the multiple receiving units 132. A method for estimating the reception angle θa is called the AoA (Angle Of Arrival) method.

[0042] For example, the multiple receiving units 132 shown in FIG. 5 are arranged at equal intervals along the x-axis direction. For example, the +x direction is the east direction. When a mobile terminal 2 is located far enough away from all of the multiple receiving units 132, the radio waves emitted by the transmitting unit 231 of the mobile terminal 2 are received by each of the receiving units 132 at a substantially constant receiving angle θa with respect to the x-axis direction. Since the multiple receiving units 132 are arranged differently, a phase difference occurs in the received radio waves. Therefore, the processor 11 calculates the receiving angle θa based on this phase difference, a predetermined frequency of the radio waves, and the interval between the receiving units 132.

[0043] Then, the processor 11 estimates the direction of the mobile terminal 2 relative to the estimation device 1 based on the calculated reception angle θa as information on the user of the mobile terminal 2 (hereinafter referred to as user information). The processor 11 may calculate the reception angle θa based on the intensity difference of the radio waves received by each of the multiple receiving units 132. The processor 11 may also estimate the distance from the estimation device 1 to the mobile terminal 2 based on the intensity difference of the received radio waves. The processor 11 generates information on the estimated direction and distance as user information of the mobile terminal 2.

[0044] <Radio wave transmission angle> Fig. 6 is a diagram showing an example of the transmission angle of the radio wave transmitted by the transmitting unit 131. As shown in Fig. 6, the estimation device 1 has a plurality of transmitting units 131 arranged at a predetermined interval along, for example, the x-axis. Note that the predetermined intervals may all be constant intervals, but may be different as long as they are known. These plurality of transmitting units 131 transmit radio waves from their respective positions with a predetermined phase. The radio waves are sinusoidal signals, chirp signals, pulse signals, etc.

[0045] The receiver 232 of the mobile terminal 2 receives the radio waves transmitted by each of the multiple transmitters 131. The processor 21 of the mobile terminal 2 calculates the transmission angle θd (also called the radiation angle or the transmission angle) of the radio waves based on, for example, the phase difference between the received radio waves. A method for estimating the transmission angle θd is called the AoD (Angle of Departure) method. The processor 21 specifies the direction of the mobile terminal 2 with respect to the estimation device 1 based on the calculated transmission angle θd. The processor 21 may calculate the transmission angle θd based on the intensity difference of the radio waves received by the receiver 232. The processor 21 may also calculate the distance from the estimation device 1 to the mobile terminal 2 based on the intensity difference of the received radio waves.

[0046] The processor 21 of the mobile terminal 2 converts the information on the direction and distance of the mobile terminal 2 relative to the estimation device 1 calculated by the above-mentioned operation into a signal using various modulation methods such as ASK (Amplitude Shift Keying), FSK (Frequency Shift Keying), and PSK (Phase Shift Keying), and supplies the signal to the transmission unit 231 using the controller 23. The transmission unit 231 transmits the signalized information to the estimation device 1 via radio waves. The processor 11 of the estimation device 1 receives the radio waves via the reception unit 132, extracts the above-mentioned information on the direction and distance estimated by the processor 21 from the radio waves, and estimates the direction and distance from the estimation device 1 to the mobile terminal 2 based on the extracted information. The processor 11 generates the information on the estimated direction and distance as user information of the mobile terminal 2.

[0047] In the above example, the estimation device 1 has multiple transmitters 131 or multiple receivers 132, and the direction of the mobile terminal 2 relative to the estimation device 1 is estimated using the AoA method or the AoD method by using the array antenna formed by these. However, the mobile terminal 2 may also be provided with multiple transmitters 231 or multiple receivers 232 to form an array antenna and estimate the direction of the mobile terminal relative to the estimation device 1.

[0048] In other words, the presentation system 9 described above is an example of a presentation system having multiple receivers arranged at a predetermined interval, with one of the mobile terminal and the estimation device transmitting radio waves and the other receiving radio waves, and estimating the user's position based on the phase difference or intensity difference of the radio waves received by each of the multiple receivers, and generating user information including information on the user's position.

[0049] <User's perspective> 7 is a diagram showing an example of a user's field of view identified by the mobile terminal 2. The mobile terminal 2 senses its own terminal's attitude (for example, the direction of the line of sight of the user wearing the mobile terminal) and motion information such as the moving direction and moving speed by the above-mentioned sensor 24. For example, the processor 21 of the mobile terminal 2 converts information such as the line of sight direction θs, moving direction a, moving speed, etc. of the mobile terminal sensed at that time, together with information on the direction and distance of the mobile terminal 2 with respect to the estimation device 1 calculated by the above-mentioned AoD, etc., into signals using various modulation methods, and supplies them to the transmission unit 231 by the controller 23. The transmission unit 231 transmits these signalized information to the estimation device 1 by wireless radio waves.

[0050] The processor 11 of the estimation device 1 that receives this wireless radio wave extracts information such as the above-mentioned direction, distance, line of sight direction, moving direction, moving speed, etc. The processor 11 stores in advance in the memory 12 the user's viewing angle θr centered on the line of sight direction θs at the mobile terminal 2. Therefore, the processor 11 generates, as user information, information on the position, moving direction, and viewing field of the mobile terminal 2 as seen from the estimation device 1, i.e., the user U wearing it, based on the extracted information and the information on the viewing angle θr.

[0051] The viewing angle θr may be a fixed value or may be a variable value. For example, if the sensor 24 has a sensor that detects the movement of the eyeball of the user U, the viewing angle θr may be determined according to the movement of the eyeball of the user U observed by the sensor. The viewing angle θr may also change according to the movement speed and movement acceleration of the mobile terminal 2 that are detected.

[0052] That is, the above-mentioned estimation device 1 is an example of an estimation device that generates user information of a mobile terminal by transmitting and receiving radio waves to and from the mobile terminal. The above-mentioned user information of the mobile terminal 2 is an example of user information including information on the user's position, moving direction, and field of view.

[0053] 7, the line of sight direction θs and the movement direction a are different, but this is because the user U does not necessarily move toward the front while looking straight ahead. In other words, when the user U moves toward the front while looking straight ahead, the line of sight direction θs and the movement direction a match.

[0054] The user information generated by the processor 11 is converted into a signal and transmitted on radio waves from the transmitting unit 131 via the controller 13. The processor 21 of the mobile terminal 2 receives the radio waves including the user information and identifies the approach status of the user U to the blocked area R based on the signal. The processor 21 then causes the presentation unit 25 to present the identified approach status. In other words, the mobile terminal 2 is an example of a mobile terminal that receives user information and causes a presentation device to present the approach status of the user to the blocked area based on the user information.

[0055] <Functional configuration of the estimation device> Fig. 8 is a diagram illustrating an example of a functional configuration of the estimation device 1. The processor 11 of the estimation device 1 illustrated in Fig. 8 executes a program read from the memory 12 to function as an acquisition unit 111, an angle estimation unit 112, a distance estimation unit 113, a moving direction estimation unit 114, a field of view estimation unit 115, a user information generation unit 116, and a transmission control unit 117.

[0056] The acquisition unit 111 acquires information on radio waves received by the receiving unit 132 shown in Fig. 4 via the controller 13. The angle estimation unit 112 estimates the angle (direction) of the mobile terminal 2 that has emitted the above-mentioned radio waves with respect to its own device (estimation device 1). The distance estimation unit 113 estimates the distance from the mobile terminal 2 that has emitted the above-mentioned radio waves to its own device (estimation device 1).

[0057] The movement direction estimation unit 114 estimates the movement direction of the mobile terminal 2. The visual field estimation unit 115 estimates the visual field of the user U who holds (wears) the mobile terminal 2.

[0058] The user information generation unit 116 generates “user information”, which is information about a user U who possesses the mobile terminal 2, based on the angle, distance, moving direction, and field of view information estimated by the angle estimation unit 112, distance estimation unit 113, moving direction estimation unit 114, and field of view estimation unit 115, respectively.

[0059] The transmission control unit 117 instructs the controller 13 to transmit the generated user information from the transmission unit 131 shown in Fig. 4. As a result, the user information is carried on radio waves using various modulation methods and transmitted from the transmission unit 131.

[0060] <Functional configuration of mobile terminal> Fig. 9 is a diagram showing an example of a functional configuration of the mobile terminal 2. The processor 21 of the mobile terminal 2 shown in Fig. 9 executes a program read from the memory 22, thereby functioning as an acceleration acquisition unit 211, a rotation angle acquisition unit 212, a signal acquisition unit 213, a direction identification unit 214, a determination unit 215, a presentation control unit 216, and a transmission control unit 217.

[0061] The acceleration acquisition unit 211 acquires information on the acceleration of the terminal itself from an acceleration sensor 241 included in the sensor 24. The rotation angle acquisition unit 212 acquires information on the rotation angle of the terminal itself from a gyro sensor 242 included in the sensor 24.

[0062] 3 via the controller 23. The direction identification unit 214 identifies the direction of the mobile terminal 2 relative to the estimation device 1, estimated by the AoA method or the AoD method, based on the signal acquired by the signal acquisition unit 213.

[0063] The determination unit 215 obtains information on acceleration, rotation angle, and direction from the acceleration acquisition unit 211, the rotation angle acquisition unit 212, and the direction identification unit 214, respectively. Then, based on this information, the determination unit 215 grasps the approach status of the user U carrying the mobile terminal 2 to the blocked area R, and determines whether the user U is in danger. Furthermore, the determination unit 215 supplies the obtained information on acceleration and rotation angle to the transmission control unit 217. Note that the determination unit 215 may also supply information on the direction identified by the direction identification unit 214 to the transmission control unit 217.

[0064] When the determination unit 215 determines that the user U is in danger based on the above-described approach situation, the presentation control unit 216 controls the presentation unit 25 to warn the user U that he is in danger.

[0065] In other words, the presentation system 9 including a mobile terminal 2 having a processor 21 functioning as this presentation control unit 216 is an example of a presentation system that warns a user when the mobile terminal determines that the user is in danger based on the user's approach to a sealed area as the user moves around the area.

[0066] The transmission control unit 217 instructs the controller 23 to transmit the acceleration and rotation angle information supplied from the determination unit 215 from the transmission unit 231 (see FIG. 3). As a result, the acceleration, rotation angle, and direction information are carried on radio waves by various modulation methods and transmitted from the transmission unit 231. The transmission control unit 217 may also obtain direction information and instruct the controller 23 to transmit it.

[0067] <Operation of the estimation device> 10 is a flow diagram showing an example of the operation flow of the estimation device 1. The processor 11 of the estimation device 1 judges whether or not a radio wave has been received from the mobile terminal 2 (step S101), and continues this step while judging that a radio wave has not been received (step S101; NO). On the other hand, when the processor 11 judges that a radio wave has been received from the mobile terminal 2 (step S101; YES), it estimates the reception angle θa of the radio wave based on the phase difference of the radio waves received by each of the multiple receiving units 132 (step S102). The processor 11 may estimate the reception angle θa of the radio wave based on the intensity difference of the radio waves received by each of the multiple receiving units 132.

[0068] Furthermore, the processor 11 estimates the distance from the mobile terminal 2 that transmitted the received radio wave to the estimation device 1 based on the phase difference or intensity difference of the received radio wave (step S103).

[0069] Then, the processor 11 encodes information indicating the estimation result using various modulation methods, superimposes the encoded information on radio waves by the controller 13, and transmits the encoded information from the transmitter 131 to the mobile terminal 2 (step S104), and ends the process. Note that the processor 11 may return the process to step S101 after step S104.

[0070] <Mobile terminal operation> 11 is a flow diagram showing an example of the operation flow of the mobile terminal 2. The processor 21 of the mobile terminal 2 judges whether or not a radio wave has been received from the estimation device 1 (step S201), and continues this step while it judges that a radio wave has not been received (step S201; NO). On the other hand, when the processor 21 judges that a radio wave has been received from the estimation device 1 (step S201; YES), it acquires information on the acceleration sensed by the acceleration sensor 241 of the sensor 24 (step S202). In addition, the processor 21 acquires information on the rotation angle sensed by the gyro sensor 242 of the sensor 24 (step S203).

[0071] Then, the processor 21 identifies the transmission angle θd of the radio waves based on the phase difference or intensity difference of the radio waves received by the multiple receiving units 232 (step S204). The processor 21 may identify the transmission angle θd based on information superimposed on the radio waves received from the estimation device 1. For example, when the estimation device 1 transmits information on the above-mentioned reception angle θa to the mobile terminal 2 by superimposing the information on the radio waves, the processor 21 may extract this information and identify it as the transmission angle θd.

[0072] Through the above-described processing, the processor 21 identifies the moving direction, moving distance, moving speed, acceleration, and posture (i.e., the gaze direction and field of view of the user U wearing the terminal) of the own terminal. The processor 21 also identifies the position of the own terminal relative to the estimation device 1. The positional relationship between the sealed area R and the estimation device 1 is stored in advance in the memory 22. Therefore, based on this information, the processor 21 determines whether the user U wearing the own terminal is approaching the sealed area R (step S205). If it is determined that the user U is not approaching the sealed area R (step S205; NO), the processor 21 ends the processing.

[0073] On the other hand, when it is determined that the user U is approaching the sealed area R (step S205; YES), the processor 21 determines whether or not the sealed area R is within the field of view of the user U (step S206). When it is determined that the sealed area R is within the field of view of the user U (step S206; YES), the processor 21 displays a message that the user U is approaching the sealed area R (step S207) and ends the processing. In this case, since the sealed area R is within the field of view, it is determined that the user U is not in danger, but by informing the user U that he is approaching, it is possible to prevent an accident due to the carelessness of the user U.

[0074] On the other hand, if it is determined that the blocked area R is not within the user U's field of view (step S206; NO), the processor 21 instructs the presentation unit 25 to warn the user U that he or she is in danger (step S208), and terminates the processing.

[0075] As described above, this presentation system 9 grasps the user U's approach to the sealed area R by transmitting and receiving radio waves between the mobile terminal 2 worn by the user U and the estimation device 1, and can therefore present the approach status to the user U even in poor optical conditions such as fog or dust.

[0076] The configurations, shapes, sizes, and layouts described in the above embodiments are merely schematic to the extent that the present invention can be understood and practiced. Therefore, the present invention is not limited to the described embodiments, and may be modified in various forms without departing from the scope of the technical ideas set forth in the claims.

[0077] <Modification> The above is a description of the embodiment, but the contents of this embodiment may be modified as follows. In addition, the following modifications may be combined.

[0078] <1> In the above-described embodiment, the presentation unit 25 is configured to be included in the mobile terminal 2, but the mobile terminal 2 does not have to have the presentation unit 25. In this case, the presentation system 9 may have a presentation device 3 separate from the mobile terminal 2, instead of the presentation unit 25 of the mobile terminal 2. FIG. 12 is a diagram showing an example of the presentation device 3 in a modified example. The mobile terminal 2 has an interface 25a instead of the presentation unit 25. This interface 25a is a communication circuit that connects to the presentation device 3 held by the user U so as to be able to communicate wirelessly or via wire.

[0079] The presentation device 3 is a device having a display screen such as a liquid crystal display and a sound emitting device such as a speaker, and is, for example, a tablet PC, a smartphone, etc. The processor 21 of the mobile terminal 2 worn by the user U issues an instruction to the presentation device 3 via the interface 25a to present the approach status of the user U to the sealed area R.

[0080] <2> In the above embodiment, the processor 21 of the mobile terminal 2 functions as the determination unit 215 that determines whether the user U is in danger according to the approach situation, but this determination may be made by a configuration different from the processor 21. For example, in the above-mentioned modified example, the processor (not shown) of the presentation device 3 may perform this determination. In this case, the processor of the presentation device 3 may obtain information on the approach situation of the user U to the closed area R via the interface 25a, and determine whether the user U is in danger based on this information. Then, when the processor of the presentation device 3 determines that the user U is in danger, it may present the approach situation and issue a warning. Note that the processor of the presentation device 3 may obtain information on the approach situation specified by the mobile terminal 2, but may also obtain information on which the approach situation is based. The "information on which the approach situation is based" here is, for example, information on the position, moving direction, moving distance, moving speed / acceleration, and attitude of the mobile terminal 2 relative to the estimation device 1 in the coordinate system.

[0081] That is, this presentation system 9 is an example of a presentation system in which the presentation device warns a user when it determines that the user moving around the venue is in danger based on the user's approach to a sealed-off area.

[0082] <3> In the above-described embodiment, each of the mobile terminals 2 may be assigned with identification information that allows the mobile terminal 2 to be identified. In this case, each of the mobile terminals 2 may transmit the identification information that identifies the mobile terminal 2 to the estimation device 1 via radio waves. Then, the estimation device 1 may extract the identification information included in the received radio waves. The estimation device 1 distinguishes the received radio waves for each mobile terminal 2 that is the source of the radio waves. Then, the estimation device 1 may add the identification information extracted from the radio waves to user information generated for each mobile terminal 2, encode the information, and transmit the information superimposed on the radio waves. When the radio waves transmitted by the estimation device 1 include identification information indicating the mobile terminal, the multiple mobile terminals 2 may use the radio waves as intended for the mobile terminal.

[0083] In other words, the presentation system 9 in this modified example is an example of a presentation system in which a mobile terminal transmits identification information identifying the terminal itself via radio waves, and an estimation device transmits user information to the mobile terminal indicated by the identification information contained in the received radio waves.

[0084] <4> In the above-described embodiment, the estimation device 1 and the mobile terminal 2 each use a CPU as a processor, but other processors may be used. The other processor may be a programmable logic device, such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC), or may include these. [Explanation of symbols]

[0085] 1...estimation device, 11...processor, 111...acquisition unit, 112...angle estimation unit, 113...distance estimation unit, 114...movement direction estimation unit, 115...field of view estimation unit, 116...user information generation unit, 117...transmission control unit, 12...memory, 13...controller, 131...transmission unit, 132...reception unit, 2...mobile terminal, 201...lens, 202...rim, 203...bridge, 204...temple, 21...processor , 211...acceleration acquisition unit, 212...rotation angle acquisition unit, 213...signal acquisition unit, 214...direction identification unit, 215...judgment unit, 216...presentation control unit, 217...transmission control unit, 22...memory, 23...controller, 231...transmitter, 232...receiver, 24...sensor, 241...acceleration sensor, 242...gyro sensor, 25...presentation unit, 25a...interface, 3...presentation device, 9...presentation system.

Claims

1. The present invention includes an estimation device that is present in a field having a closed area, a mobile terminal carried by a user moving through the field, and a presentation device, The estimation device generates user information of the mobile terminal by transmitting and receiving radio waves to and from the mobile terminal; The mobile terminal receives the user information and causes the presentation device to present the user's approach status to the blocked area based on the user information.

2. When the mobile terminal or the presentation device determines that the user is in danger based on the approach situation, the mobile terminal or the presentation device issues a warning to the user. The presentation system of claim 1 .

3. The mobile terminal is equipped with the presentation device. The presentation system of claim 1 .

4. The user information includes information on the user's position, movement direction, and field of view. The presentation system of claim 1 .

5. The mobile terminal transmits identification information for identifying the mobile terminal via the radio waves; The estimation device transmits the user information to the mobile terminal indicated by the identification information included in the received radio wave. The presentation system of claim 1 .

6. One of the mobile terminal and the estimation device transmits the radio waves; The other has a plurality of receivers arranged at a predetermined interval for receiving the radio waves, estimates the position of the user based on a phase difference or an intensity difference of the radio waves received by each of the plurality of receivers, and generates the user information including information on the position. The presentation system of claim 4.

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