JP7026079B2 - Magnetic communication system - Google Patents

Description

The present invention relates to a magnetic communication system, and more particularly to a magnetic communication system suitable for using a mobile communication terminal device (such as a smartphone or tablet) as a receiving device.

[Conventional magnetic communication]
As a communication system for transmitting and receiving predetermined information, a communication method called a magnetic communication system has been proposed, although it is not common. In this magnetic communication system, for example, as described in Patent Document 1, on the data transmission device side, a current is supplied from a transmission circuit to a coil wound around a magnetic core, while a bit of data transferred by the transmission circuit. The on / off of the coil current is controlled according to the value (“1” / “0”). On the other hand, on the data receiving device side, when the voltage generated in the coil is processed by the receiving circuit, the voltage of the coil is differentiated by the differentiating circuit to extract the voltage change, and the positive pulse is detected by the first slicer. Bit data (“1” / “0”) is reproduced by detecting a negative pulse with the second slicer and applying both outputs to the SR (set reset) flip-flop. (See paragraph 0002 of Patent Document 1 above.)

Further, in recent years, communication systems using short-range wireless communication technology such as Bluetooth (Bluetooth: registered trademark trademark registration number 4477936 owned by Bluetooth SIG) have become widespread. As such a communication system, for example, there is a system described in Patent Document 2. The system of Patent Document 2 provides a method and a device for ordering and keeping records of health care activities, in which an entity in an area (arbitrary patient, nurse, doctor, medication container, etc.) is provided. And the tag of the optional patient's physical patient file) scans the nursing area of any patient in that area, reads the identification data from the tag in response to the detection of the tag of the area's existence, and through the user interface. In addition to the wireless automatic identification (RFID) tag, a bluetooth tag is exemplified as the tag while receiving input data regarding an arbitrary patient by a health care personnel (Summary of Patent Document 2, claim 2, claim 2). See claim 10).

Japanese Unexamined Patent Publication No. 11-8574 Special Table 2013-591954

Here, with respect to an object or a person at a specific position to be detected (hereinafter, may be referred to as a "detection object"), the position of the detection object or (from a specific object or the like). ) There are cases where you want to detect the relative distance and use the detection result for specific processing. For example, in such a case, a detection target that is in a stationary state (hereinafter, may be referred to as a “stationary object”) is compared with a detection target that is a moving object (hereinafter, “moving object”). When) is close to or separated from each other, the position of the stationary object and the relative distance (from the moving object) are notified to the mobile communication terminal device such as a smartphone carried by the moving object. , The mobile terminal communication device of a moving object may be used to provide predetermined information (voice, video, etc.) to the outside. As an example of such a case, a person carrying a mobile communication terminal device is seated in a specific chair (as a stationary object) which is an exhibit at a place where furniture is displayed and exhibited, such as a furniture exhibition hall. Occasionally, information about a particular chair (manufacturer, price, quality, etc.) is output by voice or image from the seated person's mobile communication terminal device, and the chair information is provided to that person. It is conceivable to do.

In this case, as in Patent Document 2, when the position information of a stationary object and the distance information (for a person) are acquired by using Bluetooth, for example, it is adopted from Bluetooth 4.0 (Bluetooth Low Energy (BLE)). Using the proximity profile (PXP), pairing is performed between the Bluetooth installed on a stationary object and the Bluetooth built in a mobile communication terminal device carried by a person, and the Bluetooth on the stationary object side and mobile communication. The relative distance to the Bluetooth on the terminal device side is monitored, and when the monitored relative distance becomes sufficiently small, the person is sufficiently close to the stationary object (for example, when the stationary object is a chair). , That person is seated in the chair) and provides the person with information about the stationary object (for example, if the stationary object is a chair, provide the person with information about the chair). ) Is possible. However, according to the empirical experiments of the present inventors, when the above-mentioned detection is performed using the bluetooth, there are a plurality of stationary objects as detection objects and the distance between the stationary objects becomes small. (That is, when a predetermined number of stationary objects are close to each other in a certain area range), for example, when a plurality of stationary objects are present within a range of several meters in diameter, the positions of the plurality of stationary objects are accurate. It turned out that it could not be determined. That is, when there are multiple stationary objects (with the Bluetooth to be paired fixed) around the person carrying the mobile communication terminal device (with built-in Bluetooth) (that is, in the vicinity position and the distance position of the person, respectively). In the case of a stationary object), in the Bluetooth monitoring result, the stationary object in the vicinity of the person is judged to be the stationary object in the separated position, or conversely, the stationary object is in the separated position when viewed from the person. It has been confirmed that a stationary object is judged to be a stationary object in a nearby position.

Although it is conceivable to use the RFID tag described in Patent Document 2 when acquiring the position information of a stationary object and the distance information (for a person) as described above, a detection device (RFID) for detecting the RFID tag is also conceivable. The reader) is not usually built into a mobile communication terminal device such as a smartphone (unlike Bluetooth), and it is necessary to prepare a separate detection device and connect it to the mobile communication terminal device, such as usability and economy. It is inconvenient in that.

On the other hand, it is conceivable to acquire the position information of a stationary object and the distance information (for a person) as described above by using a magnetic communication system as described in Patent Document 1, but in this case, Patent Document 1 describes it. As explicitly stated, conventional magnetic communication systems need to align magnetic cores on both communicating devices to keep the distance between them to a minimum. Therefore, in the conventional magnetic communication system, one or both magnetic core units are pressed against the other magnetic core unit by the pressure of a spring. (See paragraph 0003 of Patent Document 1 above.) On the other hand, in the above-mentioned conventional example, the force due to the spring becomes a force for separating the communicating devices, and the connection is stabilized by locking the communicating devices. The magnetic core unit according to the invention of Patent Document 1 is one of the magnetic cores provided in both the communicating devices because there is a problem that the operation is troublesome and the cost of the locking mechanism becomes a problem. A DC current is passed through the coil wound around the magnetic core of the above, and an attractive force is exerted between the magnetic cores. However, in this case as well, as in the case of the conventional magnetic communication system, it is necessary to align the positions of the magnetic cores provided in both the communicating devices and keep the mutual distance to the minimum. That is, when the above-mentioned position information of a stationary object or distance information (for a person) is acquired by using a magnetic communication system as described in Patent Document 1, the position of one of the magnetic cores fixed to the stationary object is obtained. In addition, it is necessary to align the position of the other magnetic core fixed to the mobile communication terminal device and fix the positions of both magnetic core devices to each other at the minimum distance (usually considered to be about several cm). Therefore, in the conventional magnetic communication system, when the distance between the stationary object and the moving object becomes large to some extent (for example, the detection device fixed to the chair as a stationary object and the moving object as in the case of the position detection of the chair described above). It cannot be applied to (when the distance between the detection device fixed to the mobile communication terminal device as an object is several tens of cm or several meters).

Therefore, in the present invention, when the distance between a stationary object and a moving object becomes large to some extent (in particular, the distance between the detection device fixed to the stationary object and the detection device fixed to the mobile communication terminal device as a moving object). Can be applied to cases where the distance is several tens of centimeters or several meters), and when there are a plurality of stationary objects to be detected and the distance between the stationary objects is small (that is, a certain area). Accurately determine the position of each of a plurality of stationary objects even if there are a plurality of stationary objects in close proximity to each other in the range), for example, even if there are a plurality of stationary objects within a range of several meters in diameter. It is an object of the present invention to provide a magnetic communication system that can be used.

Further, the present invention utilizes a geomagnetic sensor (sometimes called an electronic compass or a digital compass) as a magnetic sensor built in a mobile communication terminal device to generate an AC magnetic signal from a stationary object as a detection target. It is an object of the present invention to provide a magnetic communication system capable of accurately providing information such as the position and distance of a stationary object to a mobile communication terminal device as a moving object by detecting the object.

The magnetic communication system of the present invention comprises one transmitting side device and one receiving side device. The one transmitting side device is fixed to a stationary object as a detection target, and includes a signal wave pattern setting means for generating a signal wave pattern composed of a predetermined combination of signal waves for uniquely expressing predetermined information. It includes a side control unit and a magnetic field generation coil that outputs an AC magnetic signal corresponding to the signal wave pattern. The signal wave pattern setting means sets n electric signal waves of different frequencies, which are two or more predetermined numbers, and expresses an n-ary number by the n electric signal waves which are the predetermined number, and also expresses the n-ary number. By continuously outputting the electric signal wave of the above by m digits, which is a predetermined number of digits, a function of forming one signal wave pattern expressing information of n-ary m digits is realized. The signal wave pattern generation means can be realized by the signal wave pattern setting means, the fundamental wave generation circuit, the modulation circuit, etc. of the embodiment described later. On the other hand, the one receiving side device is fixed to a moving object, determines the signal wave pattern based on the magnetic sensor that detects the AC magnetic signal and the output of the detection result of the magnetic sensor, and determines the signal wave pattern. It is provided with a receiving side control unit that determines the unique information expressed by. The frequency of the signal wave constituting the signal wave pattern is set to a frequency in an ultra-low frequency band whose upper limit is 100 Hz or less . The receiving side control unit receives the output of the magnetic sensor, analyzes the signal wave pattern from the transmitting side device which is the source of the electric signal from the magnetic sensor, and outputs a command signal corresponding to the signal wave pattern. Realize the function to output.

According to the present invention, when the distance between a stationary object and a moving object becomes large to some extent due to the configuration as described above (particularly, the detection device fixed to the stationary object and the mobile communication terminal device as the moving object are fixed to the present invention. It can also be applied (when the distance to the detection device is several tens of centimeters or several meters), and there are a plurality of stationary objects as detection objects, and the distance between these stationary objects becomes small. When (that is, when a predetermined number or more of stationary objects are closely present in a certain area range), for example, even when a plurality of stationary objects are present within a range of several meters in diameter, a plurality of stationary objects. The positions of each can be accurately determined.

FIG. 1 is a plan view showing the overall configuration of the transmitting side device of the magnetic communication system according to the embodiment of the present invention (with the recess cover removed and the internal configuration of the accommodating recess). FIG. 2 is an exploded perspective view showing the overall configuration of the transmitting side device of the magnetic communication system according to the embodiment of the present invention (with the recess cover removed and the internal configuration of the accommodating recess). FIG. 3 is an exploded perspective view for explaining a magnetic field in the transmitting side device of the magnetic communication system according to the embodiment of the present invention (shown together with the internal configuration of the accommodating recess by removing the recess cover). FIG. 4 is a perspective view showing a usage example of the magnetic communication system according to the embodiment of the present invention. FIG. 5 is a perspective view showing another usage example of the magnetic communication system according to the embodiment of the present invention. FIG. 6 is a functional block diagram showing an example of a control system of a magnetic communication system according to an embodiment of the present invention. FIG. 7 is an explanatory diagram (waveform diagram) schematically showing an example of a signal wave constituting a signal wave pattern of the magnetic communication system according to the embodiment of the present invention. FIG. 8 is an explanatory diagram (schematic diagram) schematically showing an example of a signal wave pattern and a fast Fourier transform process of the magnetic communication system according to the embodiment of the present invention. FIG. 9 is an explanatory diagram showing an example of a signal wave pattern of a magnetic communication system according to an embodiment of the present invention and an example of a fast Fourier transform process. FIG. 10 is an explanatory diagram showing an example of a fast Fourier transform result in the receiving side control unit of the magnetic communication system according to the embodiment of the present invention. FIG. 11 is an explanatory diagram (table) showing the first half of an example of analysis of a signal wave pattern by a receiving side control unit of a magnetic communication system according to an embodiment of the present invention. FIG. 12 is an explanatory diagram (table) showing the latter half of an example of analysis of a signal wave pattern by a receiving side control unit of a magnetic communication system according to an embodiment of the present invention.

Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described. Throughout each embodiment, the same members, elements or parts are designated by the same reference numerals, and the description thereof will be omitted. In the following description, the "... means" may refer to a configuration using hardware resources configured to realize a predetermined function corresponding to a predetermined electric / electronic component, an electronic element, or the like. , The CPU, ROM, RAM, external storage device, input device, output device, and other hardware resources of the computer device are operated by commands from a predetermined program to realize the corresponding predetermined functions. In some cases, it refers to a configuration based on software resources, and in some cases, it refers to a configuration consisting of a combination of hardware resources and software resources. In any case, if the configuration by hardware resources can be replaced by the configuration by software resources for a certain "means", the configuration by such software resources is also within the scope of the invention, and it depends on the software resources. If the configuration can be replaced by a configuration with hardware resources, such a configuration with hardware resources is also within the scope of the invention.

[Overall configuration of magnetic communication system]
The present invention can be embodied as a magnetic communication system according to the embodiment shown in FIGS. 1 to 12. Hereinafter, the overall configuration of this magnetic communication system will be schematically described first with reference to FIGS. 1 to 6. The magnetic communication system of the present embodiment is composed of a transmitting side device (transmitting unit) S shown in FIGS. 1 to 3 and 6 and a receiving side device (receiving unit) R shown in FIGS. 4 and 6. By performing magnetic communication between the transmitting side device S and the receiving side device R, the information of the transmitting side device S is received by the receiving side device R, and a predetermined process or a predetermined operation according to the content of the information is performed. Etc. are configured to be executed by a computer device. Specifically, the transmitting side device S constitutes a communication device on the stationary object side of the detection target object, and can be detachably fixed to a predetermined position or a predetermined portion of the stationary object as the detection target object. It has a predetermined size and shape according to the shape and size of a stationary object, a predetermined detachable structure, etc., and generates an AC magnetic field (AC magnetic field) in a predetermined mode according to the application and specifications of the magnetic communication system. It is provided with an electrical configuration and an electronic configuration for the purpose of, and can freely transmit a predetermined AC magnetic signal corresponding to the generated AC magnetic field to the outside. On the other hand, the receiving-side device R constitutes a communication device on the moving object side of the detection target object, receives an AC magnetic signal from the transmitting-side device S, and receives a predetermined AC magnetic signal according to the AC magnetic signal. It has an electrical configuration and an electronic configuration for outputting an electrical signal (typically, a predetermined electrical signal for causing a computer device to perform a predetermined process or operation), and a predetermined electrical signal corresponding to the output electrical signal is provided. Computer devices are designed to perform processing and operations.

[Sender device]
Next, the transmitting side device S of the present embodiment will be described in detail. As shown in FIGS. 1 to 3, the transmitting side device S includes a substrate 10, a transmitting side control unit 20, and a magnetic field generation coil 30. Specifically, the substrate 10 supports and accommodates the transmission side control unit 20 and the magnetic field generation coil 30 as a base member of the transmission side device S, and has a configuration that can be freely attached to a stationary object such as a chair or a desk. ing.

<Hypokeimenon>
The substrate 10 includes a base 11 having a predetermined shape such as a rectangular plate as a whole. The base 11 is formed of, for example, a wood material, a synthetic resin material, a metal material, or the like so as to have the predetermined shape, has a predetermined rigidity according to the material, and is not easily deformed by an external force. There is. The base 11 has a flat plate shape having a uniform predetermined thickness dimension as a whole, and has a predetermined width direction dimension (horizontal dimension in FIG. 1) and a predetermined length direction dimension (vertical dimension in FIG. 1). The outer contour thereof is a square outer contour (as a kind of rectangular shape) as shown in FIG. Further, a housing recess 12 is formed in the central portion of one side surface (upper surface side in the illustrated example) of the base portion 11 in the thickness direction. The accommodating recess 12 has a concave shape having a predetermined thickness dimension (that is, a predetermined depth) (smaller than the thickness dimension of the base 11), and has a predetermined width direction dimension (horizontal dimension in FIG. 1) and a predetermined depth. It has a length direction dimension (vertical dimension in FIG. 1), and its outer contour has a predetermined shape (corresponding small rectangular shape when the base 11 is rectangular) corresponding to the outer contour of the base 11. It is an outer contour. Further, on one side surface in the thickness direction of the base portion 11, a circular accommodating groove 13 is formed on the outside of the accommodating recess 12 at a substantially intermediate position between the outer peripheral edge of the base portion 11 and the accommodating recess 12. The accommodating groove 13 has a channel groove shape or a recessed groove shape having the same thickness dimension (that is, the same depth) as the accommodating recess 12, and accommodates the accommodating recess 12 on one side surface in the thickness direction of the base 11. A communication groove 14 that communicates the accommodating recess 12 and the accommodating groove 13 is formed at a predetermined position in the portion between the groove 13 and the accommodating groove 13. The communication groove 14 has the same thickness as the accommodating recess 12 and the accommodating groove 24. It has a channel groove shape or a concave groove shape (that is, the same depth).

Here, in the examples of FIGS. 1 to 3, the base 11 is formed in a square plate shape, but it can also be in another rectangular plate shape such as a rectangular plate shape, or a hexagonal plate shape or an octagonal shape. It may be in the shape of another polygonal plate such as a plate, or it may be in the shape of a plate having another shape such as a circular plate or an elliptical plate. Further, the communication groove 14 is formed at the base 11 so as to connect the corner portion of the accommodating recess 12 and the circumferential position of the accommodating groove 13 (corresponding to the corner portion), but at any other portion or position. It may be formed.

<Sender control unit>
A transmission side control unit 20 is arranged and fixed at a predetermined position in the accommodating recess 12 of the substrate 10. The transmission side control unit 20 has electrical and electronic components mounted on a substrate for realizing the circuit configuration of the functional block of the transmission side device S shown in FIG. 6, and the substrate is mounted on the substrate 10 in the accommodating recess 12. By fixing the transmission side control unit 20 to a predetermined position on the bottom wall by a predetermined fixing means (fastening means such as a screw or screw, or a supporting means such as a bracket), the transmitting side control unit 20 is fixed at a predetermined position of the accommodating recess 12. ing. The transmission side control unit 20 basically outputs an alternating current of a predetermined frequency at a predetermined voltage to the outside at a predetermined time interval (hopping cycle). Specifically, the transmitting side control unit 20 generates AC waveforms (typically sine waves) having a plurality of different frequencies, and switches between those frequencies at predetermined intervals (that is, at regular time intervals). It has an electrical and electronic configuration for outputting an alternating current of those frequencies to the magnetic field generation coil 30 together with hopping at a predetermined hopping cycle). The transmission side control unit 20 is based on software resources (such as various programs) that enable the microcomputer to perform predetermined functions as described later with respect to various microcomputers (microcomputers) configured by hardware resources. It can be configured by combining configurations.

Specifically, as shown in FIG. 6, the transmission side control unit 20 of the transmission side device S includes a signal wave pattern setting means 21, a hopping cycle setting means 22, a fundamental wave generation circuit 23, and a modulation circuit 24. There is. Further, the transmission side device S further includes a coil drive circuit 25, a feeder line 26, and a magnetic field generation coil 30 as an electrical / electronic configuration connected to the output side of the transmission side control unit 20. Further, the transmitting side device S further includes an external input device 41 as an electrical / electronic configuration connected to the input side of the transmitting side control unit 20. The transmission side control unit 20 is a characteristic configuration of the magnetic communication device of the present embodiment, but is predetermined for various microcomputers (microcomputers) as a configuration using hardware resources, as will be described later. It can be configured by combining configurations with software resources (such as various programs) that realize the functions in the microcomputer. In the following explanation, what is called "... means" basically realizes the function by software resources, and what is called "... circuit" is basically. The function is realized by the hardware resource, but the function is not limited to this, and the function called "... means" can be realized by the hardware resource, or "... circuit". It is also possible to realize the function of what is called "" by using software resources. Although not shown, the transmission side device S is provided with an internal power supply for supplying a drive current of the transmission side control unit 20, the magnetic field generation coil 30, or the like, or an electrical connection port to which an external power supply can be freely connected. Is configured to supply the drive current of the transmission side control unit 20, the magnetic field generation coil 30, and the like.

<Signal wave pattern setting means>
More specifically, the signal wave pattern setting means 21 sets a predetermined number (n) of two or more electric signal waves of different frequencies, and expresses an n-ary number by the predetermined number (n) of the electric signal waves. At the same time, by continuously outputting the n-ary electric signal wave by a predetermined number of digits (m digits), a function of forming one signal wave pattern is realized. Specifically, the signal wave pattern setting means 21 sets, for example, two electric signal waves having different frequencies, expresses a binary number by the two electric signal waves, and expresses the binary number, and the electric signal wave of the binary number. Can be continuously output by a predetermined number of digits (2 digits, 3 digits, 4 digits, etc.) to form one signal wave pattern. In this case, 2 squared (= 4 ways in total). It is possible to generate a predetermined number of signal wave patterns such as 2 to the 3rd power (= 8 ways in total) or 2 to the 4th power (= 16 ways in total). Alternatively, the signal wave pattern setting means 21 sets, for example, three electric signal waves having different frequencies, expresses a ternary number by the three electric signal waves, and determines the electric signal wave of the ternary number. By continuously outputting only the number of digits (2 digits, 3 digits, 4 digits, etc.), one signal wave pattern can be configured. In this case, 3 squared (= 9 ways in total), 3 It is possible to generate a predetermined number of signal wave patterns such as cube (= 27 in total) or 3 to 4 (= 81 in total). Alternatively, the signal wave pattern setting means 21 sets, for example, four electric signal waves having different frequencies, expresses a quaternary number by the four electric signal waves, and determines the electric signal wave of the quaternary number. By continuously outputting only the number of digits (2 digits, 3 digits, 4 digits, etc.), one signal wave pattern can be configured. In this case, 4 squared (= 16 ways in total), 4 It is possible to generate a predetermined number of signal wave patterns such as 3rd power (= 64 ways in total) or 4 4th power (= 256 ways in total).

More specifically, in the present embodiment, the signal wave pattern setting means 21 sets four electric signal waves having different frequencies as an example of the signal wave pattern, and the four electric signal waves are used as a quaternary number. And by continuously outputting the electric signal wave of the quaternary number by 3 digits, one signal wave pattern is constructed and a signal wave pattern of 4 3 (= 64 ways in total) is generated. It has become like. Further, as the four types of electric signal waves constituting the quaternary number of this signal wave pattern, for example, a signal wave A, a signal wave B, a signal wave C, and a signal wave D as shown in FIG. 7 are set. The frequency f1 of the signal wave A, the frequency f2 of the signal wave B, the frequency f3 of the signal wave C, and the frequency of the signal wave D are set to f1 = 2.4 Hz, f2 = 4.8 Hz, f3 = 7.2 Hz, respectively. f4 = 9.6 Hz is set. In this setting, the frequency f1 (= 2.4 Hz) of the signal wave A is used as the basic frequency, and the frequency f2 of the signal wave B is twice the frequency f1 of the signal A (f2 = 2 f1 = 4.8 Hz). The frequency f3 of the signal wave C is three times the frequency f1 of the signal A (f3 = 3f1 = 7.2 Hz), and the frequency of the signal wave D is four times the frequency f1 of the signal A (f4 = 4f1 =). It is set to 9.6 Hz). In this case, the signal wave patterns of the generated electrical signal waves are {A, A, A}, {A, A, B}, {A, A, C}, {A, A, D}, {A, B, A}, {A, B, B}, {A, B, C}, {A, B, D}, ..., {D, D, A}, {D, D, B}, { D, D, C}, {D, D, D}.

In this case, the magnetic field generation coil 30 described later receives the output of the electric signal wave of the above signal wave pattern from the transmission side control unit 20, and as shown in FIG. 7, the corresponding signal wave pattern (electric signal wave). Any one signal of signal waves A, B, C, D consisting of an AC magnetic signal wave having the same frequencies f1 to f4 as the signal waves A to D and (frequency pattern represented by three quaternary digits). An AC magnetic signal that expresses three-digit quaternary information (64 different data that can be identification information or identifier) by setting the wave to a signal wave of each of the three digits and outputting it. Is output to the outside. As shown in FIG. 7, the signal waves A, B, C, and D composed of these AC magnetic signal waves are AC signal waves in which the magnetic flux density is increased or decreased with time (typically, a sine wave). Is what forms. In this case, the signal wave patterns of the generated AC magnetic signal waves are {A, A, A}, {A, A, B}, {A, A, C}, {A, A, D}, {A. , B, A}, {A, B, B}, {A, B, C}, {A, B, D}, ..., {D, D, A}, {D, D, B}, It becomes {D, D, C}, {D, D, D}.

<Hopping cycle setting means>
The hopping cycle setting means 22 is a signal wave of a predetermined signal wave pattern set by the signal wave pattern setting means 21 (that is, a continuous signal wave of a signal wave pattern of n-ary m digits, for example, a signal wave A. , B, C, D) are switched and output at a predetermined switching time interval (that is, hopping cycle) which is a fixed time interval, and a function to output a timing signal is realized. Specifically, the hopping cycle setting means 22 has the longest period (in the case of signal waves A, B, C, D) among the periods (of each signal wave) determined by the frequency of the signal wave of the set signal wave pattern. , 1 / f1 ≈ 0.42 seconds, which is the period of the signal wave A having the minimum frequency), and the hopping period is set so that the time interval is equal to or longer than the longest period. More specifically, the hopping cycle setting means 22 sets a quaternary three-digit signal wave pattern as a signal wave pattern as an example of the hopping cycle, and when the signal waves A, B, C, and D are used. , Based on the period (1 / f1 ≈ 0.42 seconds) of the signal wave A, which is the minimum frequency in the signal waves A, B, C, D, the time interval equal to or longer than the longest period is 0.6 seconds (0.6 sec). ), The hopping cycle is set. Then, in this case, the four signal waves (which are electric signal waves) of the peripheral number pattern represented by the three digits of the quaternary number consisting of the signal waves A to D are switched by the hopping cycle setting means 22 at a predetermined hopping frequency. While (while being hopping), by setting and outputting each of the signal waves of each of the three digits, information of three digits of the quaternary number (64 different data, which can be identification information or an identifier) is output. The AC electric number to be expressed is output. Specifically, in this case, the hopping cycle setting means 22 is used to signal waves (signal 1, signal) having three digits (first digit x 1, second digit x 2, third digit x 3) as shown in FIG. 2. As the signal 3), one of the signal waves A, B, C, and D is hopping and set, respectively, so that the four signal waves A, B, C, and D constituting the quaternary number are set. Any one signal wave A, B, C, D selected from the above becomes three digits (x1x2x3), and a continuous electric signal wave of a predetermined signal wave pattern is generated.

As a result, the magnetic field generation coil 30, which will be described later, receives the output of the electric signal wave of the above signal wave pattern from the transmission side control unit 20, and as shown in FIG. 8, the corresponding signal wave pattern (electric signal wave). It has the same frequencies f1 to f4 as the signal waves A to D, and has three digits while switching (hopping) four signal waves (a peripheral number pattern expressed by three quaternary digits) at a predetermined hopping frequency. By setting each digit of the signal wave and outputting it, an AC magnetic signal expressing 3-digit quaternary information (64 different data that can be identification information or an identifier) is output to the outside. do. Specifically, in this case, the magnetic field generating coil 30 has a signal wave (signal 1, signal) having three digits (first digit x 1, second digit x 2, third digit x 3) as shown in FIG. 2. As the signal 3), one of the signal waves A, B, C, and D, which are magnetic signal waves corresponding to the signal waves A, B, C, and D, which are electric signal waves, is hopping and set. By doing so, any one (magnetic signal wave) signal wave A, B, C, D selected from the four signal waves A, B, C, D constituting the quaternary number has three digits (x1x2x3). To generate a continuous AC magnetic signal wave with a predetermined signal wave pattern.

<Separation signal E>
On the other hand, the hopping cycle setting means 22 (or the signal wave pattern setting means 21) has a predetermined delimiter signal E before and after each signal wave pattern (one signal wave pattern) composed of signal waves of n-ary m digits. It also realizes the function of inserting. The delimiter signal E is a signal having a frequency at which the frequency of the signal wave of the signal wave pattern can be clearly distinguished. However, typically, as a zero frequency signal, the section in which the delimiter signal E exists is the signal. The existence of the delimiter signal E can be expressed by setting a state in which no frequency including each frequency of the waves A to D is output. That is, the hopping cycle setting means 22 (or the signal wave pattern setting means 21) is the position immediately before the first electric signal wave and the last electric signal of each set of (one) signal wave patterns generated as described above. Immediately after the wave, a delimiter signal E that continues temporally for a predetermined delimiter time interval is inserted, respectively. Here, the delimiter time interval of the delimiter signal E can be set to the same time interval as the time interval of the hopping cycle (for example, 0.6 seconds) from the viewpoint of demodulation processing by the receiving side control unit 60, which will be described later. preferable. Specifically, when an electric signal wave (signal 1, signal 2, signal 3) of a signal wave pattern consisting of a three-digit signal wave (x1x2x3) as shown in FIG. 8 is generated, the signal wave pattern Separation signals E at the same time interval are inserted at the front and rear positions of the signal wave (that is, the position immediately before the first signal wave x1 (signal 1) and the position immediately after the last signal wave x3 (signal 3)). Will be done. In reality, since the signal waves of the signal wave pattern are continuously output in a plurality of sets (usually a large number of sets) in time, after the final delimiter signal 3 in FIG. 8, further (not shown). (Although not), the signal waves of the same signal wave pattern will be continuous.

<Fundamental wave generation circuit>
The fundamental wave generation circuit 23 has a circuit configuration for generating a fundamental wave having a predetermined fundamental frequency, and can be configured by using a known waveform generation circuit. As such a fundamental wave, for example, among the signal waves constituting the n-ary m-digit signal wave pattern, a signal wave having the same frequency as the fundamental signal wave having the lowest frequency can be used. In the case of B, C, D, a signal wave (typically a sine wave) having the same frequency (2.4 Hz) as the signal wave A can be used.

<Modulation circuit>
Based on the output from the signal wave pattern setting means 21 and the output from the hopping cycle setting means 22, the modulation circuit 24 uses the fundamental signal wave output from the fundamental wave generation circuit 23 as the n-ary m-digit signal wave. It realizes the function of modulating and outputting so that it becomes the electric signal wave of the pattern. For example, in the modulation circuit 24, when a signal wave pattern consisting of a three-digit signal wave (x1x2x3) as shown in FIG. 8 is set, the electric signal wave (x1 = signal 1, x2 = signal 2, x3 =). The signal 3) is modulated and output, and the position before and after the signal wave of the signal wave pattern (that is, the position immediately before the first signal wave x1 (signal 1) and the position immediately after the last signal wave x3 (signal 3)). The delimiter signal E at the same time interval is inserted into and output to each.

That is, the magnetic field generation coil 30, which will be described later, receives the output of the electric signal wave of the above signal wave pattern from the modulation circuit 24 of the transmission side control unit 20, and as shown in FIG. 8, the corresponding signal wave pattern (electric signal). While switching (hopping) four signal waves having the same frequencies f1 to f4 as the signal waves A to D, which are waves, and having a peripheral number pattern expressed by three quaternary digits at a predetermined hopping frequency. ) An AC magnetic signal that expresses quaternary 3-digit information (64 different data that can be identification information or identifier) is output by setting each 3-digit signal wave and outputting it. Output to the outside. Specifically, in this case, the magnetic field generating coil 30 has a signal wave (signal 1, signal) having three digits (first digit x 1, second digit x 2, third digit x 3) as shown in FIG. 2. As the signal 3), one of the signal waves A, B, C, and D, which are magnetic signal waves corresponding to the signal waves A, B, C, and D, which are electric signal waves, is hopping and set. By doing so, any one (magnetic signal wave) signal wave A, B, C, D selected from the four signal waves A, B, C, D constituting the quaternary number has three digits (x1x2x3). To generate a continuous AC magnetic signal wave with a predetermined signal wave pattern.

<Coil drive circuit>
The coil drive circuit 25 realizes a function of amplifying the modulation signal from the modulation circuit 24 at a predetermined amplification factor and outputting it to the magnetic field generation coil 30 via the feeder line 26. The coil drive circuit 25 functions as a driver that amplifies the modulation signal from the modulation circuit 24 and outputs it to the magnetic field generation coil 30, and wants to generate a stronger magnetic field MF from the magnetic field generation coil 30. Since it is a preferred electrical configuration to be mounted in some cases, it can be omitted if there is no such need.

<External input device>
The external input device 41 realizes a function of inputting setting information regarding the frequency of each signal wave of the signal wave pattern and the combination of the signal waves by the signal wave pattern setting means 21 from the outside. That is, the external input device 41 provides an input interface to the signal wave pattern setting means 21 and the hopping cycle setting means 23, and is realized as a configuration using the hardware resources. Specifically, the input device provides the signal wave pattern setting means 21 with an input function for setting the signal wave pattern, and sets the hopping cycle with respect to the hopping cycle setting means 22. Provides input function. The external input device 41 may be configured as a separate device outside the transmitting side device S, and may be used by connecting to the interface of the transmitting side device S only when necessary.

<Magnetic field generation coil>
A magnetic field generating coil 30 is arranged in the accommodating groove 13 of the substrate 10 in an accommodating state. The magnetic field generation coil 30 uses a predetermined coil wire having a predetermined diameter (wire diameter) (typically, a copper wire material such as an enamel wire), and the coil wire is wound into a predetermined coil with a predetermined number of turns (N). It is formed by winding the accommodating groove 13 in the circumferential direction so as to have a diameter (D). Further, the magnetic field generation coil 30 is electrically (and electrically) connected to the transmission side control unit 20 in the accommodation recess 12 by a feeding line 26, and is an alternating current having a predetermined frequency supplied from the transmission side control unit 20. An AC magnetic field (AC magnetic field) of a corresponding frequency (basically the same frequency) is generated by a current (hereinafter, may be simply referred to as “supply current”). Further, the magnetic field generating coil 30 changes the frequency of the alternating current generated by itself to the frequency corresponding to the frequency of the supply current (basically, every time the alternating current from the transmitting side control unit 20 is switched in the predetermined hopping cycle). Switch to the same frequency) and generate an AC magnetic field of the corresponding frequency. Here, the strength (H) of the magnetic field generated by the magnetic field generating coil 30 is basically the number of turns (the position of the magnetic field center MFC which is the axial center portion as shown in FIG. 3). N) is proportional to the amount of current (I) conducting to the magnetic field generating coil 30, and is inversely proportional to the coil diameter (D = 2r), so that H = NI / 2r (A / m). Further, the magnetic flux density (B) is proportional to the strength (H) of the magnetic field, and B = μH = μNI / 2r (T) (“μ” in the formula is the magnetic permeability). Therefore, in the magnetic communication system of the present embodiment, the current value (I) of the supply current from the transmission side control unit 20, the number of turns (N) of the magnetic field generating coil 30, and the coil diameter (D =) of the magnetic field generating coil 30 2r: D is the diameter, r is the radius), and the value (parameter) of any one or more is increased or decreased, and the strength (H) of the AC magnetic field generated by the magnetic field generation coil 30 is a predetermined strength value (or , Within the specified strength range). If necessary, the type and diameter of the coil wire of the magnetic field generating coil 30 may be additionally used as such a parameter.

Specifically, the magnetic field strength generated by the magnetic field generation coil 30 is the normal distance or distance between the stationary object and the moving object, which is the detection target, when the moving object approaches the stationary object. Assuming a range (hereinafter, these may be collectively referred to as "normal distance"), the AC magnetic signal from the transmitting side device S fixed to the stationary object is fixed to the moving object at the normal distance (hereinafter, these may be collectively referred to as "normal distance"). Alternatively, it can be reliably received by the receiving side device R (which is carried by a moving object and moves integrally with the moving object), and the AC magnetic signal can be reliably demolished by the receiving side device R to restore the original information. The strength is set to be equal to or higher than the minimum strength value (hereinafter, may be referred to as "minimum strength value").

The normal distance, which is the standard for such a minimum strength value, can be grasped in advance according to the type of a stationary object. For example, as shown in FIG. 4, when the stationary object is the chair 100 and the transmitting side device S is fixed to the lower side (lower side surface) of the seat portion 101 of the chair 100, the mobile communication terminal device (that is, that is). When a person 100 as a moving object carrying the receiving side device R) sits on the chair 100 as a stationary object (carried by the person 100), the person 100 is fixed to the mobile communication terminal device (receiving side device R) and the chair 100. Since it is considered that the distance to the transmitting side device S is usually within the range of about 50 cm, or at most about 1 meter, the normal distance is also considered to be within the range of about 1 meter in this case. For example, it is practical to set it within a distance of 50 cm to 1 meter. Further, for example, as shown in FIG. 5, when the stationary object is the table 120 and the transmitting side device S is fixed to the lower side (lower side surface) of the top plate 121 of the table 120, the mobile communication terminal device ( That is, the person 100 as a moving object carrying the receiving side device R) is a mobile communication terminal device (carrying the receiving side device R) when the person 100 is seated or stopped at the nearest position of the table 120 as a stationary object. Since the distance between R) and the transmitting side device S fixed to the table 120 is also considered to be usually within a distance of about 50 cm, or at most within a distance of about 1 meter. In this case, it is practical to set the normal distance within a range of, for example, 50 cm to 1 meter.

On the other hand, the magnetic field strength generated by the magnetic field generation coil 30 is determined when a plurality of stationary objects are arranged close to each other within a predetermined area range (that is, when they are arranged two-dimensionally close to each other) or predetermined. Minimum separation distance or minimum separation distance range between adjacent stationary objects (in the two-dimensional direction or three-dimensional direction) when they are placed close to each other within the volume range (that is, when they are placed close to each other in three dimensions). , These may be collectively referred to as "minimum separation distance"), and at the midpoint of such minimum separation distance, the magnetic field generation coil 30 of the transmitting side device S fixed to the adjacent stationary object is generated. It is desirable to set the maximum value of the magnetic field strength (hereinafter, may be referred to as "intermediate point strength value") to be less than the minimum strength value. In this way, when a plurality of stationary objects are arranged adjacent to each other, the AC magnetic signal from the transmitting side device S of one of the adjacent stationary objects is the AC magnetic signal from the transmitting side device S of the other adjacent stationary object. Does not interfere with the signal. That is, when the receiving side device R of the moving object approaches both of the adjacent stationary objects, the receiving side device R always has only the AC magnetic signal from one transmitting side device S of the adjacent stationary object. (That is, the AC magnetic signal from the other transmitting side device S becomes less than the receiving sensitivity and is not received by the receiving side device R).

The minimum distance, which serves as a reference for the strength value at the intermediate point, can be grasped in advance according to the type of the stationary object, the type of the facility in which the stationary object is arranged, and the like. For example, when a plurality of chairs 100 as shown in FIG. 4 are arranged apart from each other in an indoor facility (for example, a furniture exhibition hall), the minimum separation distance between the chairs 100 arranged adjacent to each other is usually set. Since it is considered that the minimum distance is within the range of about 1 meter to 2 meters, it is practical to set the minimum separation distance within the range of, for example, 1 meter to 2 meters in this case. be. Further, for example, when a plurality of tables 120 as shown in FIG. 5 are arranged apart from each other in an indoor facility (for example, a furniture exhibition hall), the minimum separation distance between the tables 120 arranged adjacent to each other is usually set. Is also considered to be within the range of a distance of about 1 meter to 2 meters at the minimum, so in this case, the minimum separation distance should also be set within the range of a distance of, for example, 1 meter to 2 meters. Is practical.

In the present invention, the normal distance is within a range of several tens of centimeters to several meters, for example, within a range of about 50 cm to about 1 meter, within a range of about 50 cm to about 2 meters, and about 1 meter to about 2 meters. It is possible to set a relatively close distance, such as within the range of, but it is possible to set an arbitrary distance depending on the case. In any case, in recent years when the communication environment using the Internet is becoming more and more fulfilling, mobile communication terminal devices that people carry are usually typical as moving objects, so people are stationary. Assumed between the transmitting side device S on the stationary object side and the receiving side device 4 on the moving object side when approaching an object (chair, desk, table, counter, cabinet, etc.) (or sitting, sitting, etc.) It is practical to set the normal distance or the minimum separation distance on the assumption that the mobile communication terminal device will be the receiving side device R.

Further, in the present embodiment, the maximum strength of the magnetic field MF generated by the magnetic field generating coil 30 (typically, the magnetic field strength at the position of the magnetic field center MFC shown in FIG. 3) is the detection target. Assuming that a moving object is a person and that the moving object to be detected is carried by a person such as a mobile mobile terminal device, that person is the most stationary object as a detection target. The strength (or magnetic field density) of the magnetic field applied to the person when approaching is less than the standard value of the international guideline (typically, the standard value of the International Commission for Non-Ionized Radiation Protection (ICNIRP). Less than).

[Corresponding to the characteristics of the geomagnetic sensor]
Here, the present invention utilizes a geomagnetic sensor (sometimes referred to as an electronic compass or a digital compass) as a magnetic sensor built in a mobile communication terminal device to obtain an AC magnetic signal from a stationary object for which a detection target is determined. It is also one of the purposes (issues) to provide a magnetic communication system capable of accurately providing information such as the position and distance of the stationary object to the mobile communication terminal device as a moving object by detecting the above. .. Therefore, special settings and consideration are required according to the characteristics of the geomagnetic sensor (particularly, the characteristics of a general-purpose geomagnetic sensor built in a mobile communication terminal device such as a smartphone or tablet). That is, since the geomagnetic sensor is an electronic device for detecting the magnitude and direction of the geomagnetism, the present inventors have a case where the frequency is hopping and the hopping frequency is detected as in the present invention. , It was found that there is a limit to the frequency range in which each frequency can be detected accurately. That is, it was found that there is a limit to the frequencies that can be detected because it is not composed of points that detect frequencies other than the magnitude and direction of the geomagnetism. Therefore, as a result of further diligent research and development, the present inventors have set the upper limit of such a frequency to about 10 Hz in the case of a geomagnetic sensor with a built-in mobile communication terminal device that is generally distributed. I got the finding that there is. Therefore, in the present invention, the frequency of the signal wave constituting the signal wave pattern is the frequency of the signal D which is the highest frequency among the frequencies of the signal waves A, B, C, and D having an upper limit of 10 Hz or less (for example, the frequency of the signal wave A, B, C, D). Is a frequency of 10 Hz or less (9.6 Hz)), and the frequency of the signal wave is set. If the upper limit of the measurable frequency of the geomagnetic sensor (especially general-purpose built-in in mobile communication terminal devices such as smartphones and tablets) increases in the future or due to design changes, the frequency within that range will be used. You can also do it. The response frequency of the geomagnetic sensor is, for example, 100 Hz to kHz order in the case of a magnetic sensor composed of a Hall element or a fluxgate sensor, MHz order in the case of a magnetic sensor composed of an MR element or a GMR element, and a magnetic sensor composed of an MI element. In the case of, it may be on the order of 10 kHz to 100 kHz, but the characteristics of the magnetic sensor mounted on the actual mobile communication terminal device are various, and as described above, the ultra-low frequency band of about 10 Hz or the ultra-low frequency band or Since it is expected that the response frequency will be in the ultra-low frequency band of at most about 100 Hz, in the present invention, the frequency of the signal wave of the signal wave pattern is set to these ultra-low frequency bands (or ultra-low) at the maximum. It is very preferable in practice to set the frequency to be lower than the frequency band.

[Receiver]
Next, the receiving side device R of the present embodiment will be described in detail. As shown in FIG. 4, the receiving side device 4 has an electrical / electronic configuration (typically, as a mobile communication terminal device) mounted inside a smartphone as a mobile communication terminal device in the present embodiment. The configuration and functions of the receiving device 4 are realized by utilizing the electrical / electronic configuration (electrical / electronic configuration) previously mounted on the smartphone. Specifically, as shown in FIG. 6, the receiving side device R includes a magnetic sensor 51, a receiving side control unit 60, and an output means 65. Of these, first, the magnetic sensor 51 has a configuration that is preliminarily mounted in a smartphone as a mobile communication terminal device constituting the receiving side device R, and this magnetic sensor (electronic compass) is used in the present embodiment. It is used as a magnetic sensor 51. Specifically, the magnetic sensor 51 detects an AC magnetic signal from the magnetic field generation coil 30 of the transmitting side device S (that is, by detecting a change in magnetic flux density and a change in the direction of the magnetic field). Then, an electric signal corresponding to the signal wave pattern of the AC detection signal is output. That is, when an AC magnetic signal of a signal wave pattern having a quaternary digit of 3 digits consisting of the above signals A, B, C, and D is output, the magnetic sensor 51 corresponds to each digit of the signal wave pattern ( It detects an AC magnetic signal (as a magnetic signal wave) and outputs an electric signal corresponding to the AC magnetic signal (signal waves A, B, C, D).

<Receiver control unit>
The receiving side control unit 60 receives the output of the magnetic sensor 51, analyzes the signal wave pattern from the transmitting side device S which is the source of the electric signal from the magnetic sensor 51, and commands corresponding to the signal wave pattern. Realizes the function to output a signal. The receiving side control unit 60 is based on software resources (such as various programs) that enable the microcomputer to perform predetermined functions as described later for various microcomputers (microcomputers) configured by hardware resources. It can be configured by combining configurations. Specifically, the receiving side control unit 60 can be configured to include a demodulation circuit 61, a pattern recognition means 62, a matching means 63, and a command means 64.

<Demodulation circuit>
The demodulation circuit 61 inputs an electric signal which is an output signal of the magnetic sensor 51, demodulates each signal wave of a predetermined signal wave pattern transmitted by the transmitting side device S based on the electric signal, and demodulates the demodulated signal. Along with realizing the function of outputting the signal, the function of extracting the spectral component by high-speed Fourier conversion of the demodulated signal is realized. Specifically, the demodulation circuit 61 includes demodulation means that is means for demodulating the signal wave of the signal wave pattern from the transmitting side device S based on the electric signal from the magnetic sensor 51 , and demodulation from the demodulation means. It is equipped with FFT means for fast Fourier transform of the signal. In the demodulator circuit 61, when the output signal of the magnetic sensor 51 is an AC signal waveform that faithfully restores the signal wave pattern from the transmitting side device S (that is, the magnetic sensor 51 has such characteristics and performance). , Etc.), the electric signal from the magnetic sensor 51 can be directly input to the FFT means to perform a fast Fourier transform. In this case, the demodulation means can be omitted. The FFT means itself of the demodulator circuit 61 can be composed of a known high-speed Fourier transform circuit or the like, but this FFT means is more than the hopping period (for example, 0.6 sec) of the signal wave pattern by the transmitting side control unit 20. One fast Fourier transform is performed in a conversion cycle with a short time interval (for example, 0.4 sec), and one fast Fourier transform (hereinafter, may be referred to as "unit FFT") is performed a predetermined number of times. (Hereinafter, it may be referred to as "the number of FFTs for one pattern"), and the conversion cycle (that is, timing) of the adjacent unit FFT is set at a part of the time interval (hereinafter, "superimposition time interval"). It is configured to perform the fast Fourier transform for the number of FFTs for one pattern by superimposing only (.).

Specifically, the FFT means processes, as the superposition time interval, in two adjacent unit FFTs, one unit FFT straddling the adjacent signal wave (of the m-digit continuous signal wave). In that case (ie, if part of the time interval of one unit FFT belongs to the time interval of one signal wave and the other time interval belongs to the time interval of the other signal wave), the other unit. The time interval is set so that the entire FFT time interval is completely included in the time interval of the other signal wave. Further, the FFT means performs a fast Fourier transform for the number of FFTs for one pattern based on the ratio of the conversion cycle of the unit FFT to the hopping cycle and the ratio of the superimposed time interval as the number of FFTs for one pattern. The number of times that the signal wave of the set of signal wave patterns can be completely covered and the fast Fourier transform process can be performed by covering at least a part of the dividing signals before and after the signal wave is set.

Specifically, for example, as shown in FIG. 8, hopping is performed when a three-digit signal wave (x1x2x3) is used as a signal wave pattern and a set of signal wave patterns is separated by a delimiter signal E and recognized. When the cycle is 0.6 seconds, the cycle of the unit FFT by the FFT means is set to 0.4 seconds, the superimposition time interval is set to 0.2 seconds, and the FFT for one pattern is set. The number of times is set to 10. By doing so, the FFT means repeats the unit FFT (FFT01 to FFT10) in a predetermined cycle (0.4 seconds) for the number of FFTs for one pattern (10 times), and the adjacent unit FFTs are repeated at a predetermined superposition time interval (FFT01 to FFT10). By superimposing in 0.2 seconds), the number of FFTs for one pattern is within the range of the entire time interval of a set of signal wave patterns including at least one of the preceding and following dividing signals E. The time interval of the Fast Fourier Transform process of the By superimposing on the FFT means, the FFT means can completely extract the spectral components of all the signal waves of the set of signal wave patterns and recognize the frequency of the signal wave of the set of signal wave patterns. It has become. Further, the FFT means superimposes the time interval of the first unit FFT or the last unit FFT on a part of the time interval of the delimiter signal E of at least one (front or rear), so that at least one (front or rear) It is possible to recognize the existence of the delimiter signal E (that is, the zero frequency before the first signal wave of the signal wave pattern, or the zero frequency after the last signal wave). The total value of the unit FFT cycle (0.4 seconds) and the superimposed time interval (0.2 seconds) is equal to the hopping cycle (0.6 seconds). Further, the superimposed time interval (0.2 seconds) is a time interval that is half (1/2) of the cycle (0.4 seconds) of the unit FFT. As a result, there is always a unit FFT that "does not straddle" hopping (that is, the time interval of one signal wave) at least once during the hopping cycle of 0.6 seconds.

Further, the FFT means selectively uses only the extraction spectrum of the unit FFT at regular intervals among the unit FFTs of the number of FFTs for one pattern, so that the frequency of the signal wave of the set of signal wave patterns can be obtained. It is designed to recognize accurately. For example, as shown in FIG. 8, a three-digit signal wave (x1x2x3) is used as the signal wave pattern, and one set of signal wave patterns is recognized by being separated by the delimiter signal E, and the hopping period is set to 0.6 seconds. When the number of FFTs for one pattern is 10 times, the FFT means has every two of the last unit FFT and the previous unit FFT, as shown by diagonal lines in FIG. Select the extraction spectrum of the unit FFT of, select a total of 4 candidate spectra, and use these 4 candidate spectra (that is, the extraction spectra of the 1st, 4th, 7th, and 10th unit FFT). Then, the frequency of the signal wave of the set of signal wave patterns is accurately analyzed and recognized. More specifically, as shown in FIG. 9, a set of signal wave patterns is composed of continuous signal waves of signal wave ABC, and signal wave A, signal wave B, and signal wave C each have a predetermined hopping period. When the output is performed at a predetermined timing (between t1 and t2, between t2 and t3, and between t3 and t4), the FFT means sets the unit FFT (FFT01 to FFT10) of the number of FFTs for one pattern (10 times). The superimposition is performed at superimposition time intervals, and the extraction spectra of the predetermined four units FFTs are selected as candidate spectra. That is, the extraction spectrum of the unit FFT (FFT01 to FFT10) of the number of FFTs (10 times) for one pattern by the FFT means has a spectral component as shown in FIG. The extraction spectrum of the minute unit FFT (FFT01, FFT04, FFT07, FFT10) is output as a candidate spectrum. Then, as shown in FIG. 10, each candidate spectrum becomes a spectrum that almost accurately reflects the spectrum of the corresponding signal wave, and is output as a spectrum that accurately represents the frequency of the signal wave of the set of signal wave patterns. Can be done.

Further, the FFT means is expressed by connecting n signals (A, B, C, D, etc.) having different frequencies by m digits, which are represented by signal waves analyzed by the extraction spectrum of the unit FFT. Based on the ratio of the signal strength of the code having the second (second) signal strength to the code having the maximum signal strength among the codes consisting of the information of each digit of the information of the base m digits). The "signal-likeness" of the code is calculated. Specifically, the FFT means has a value of the ratio of the maximum signal strength to the second signal strength (for example, the maximum signal strength is the second signal strength) for each of the predetermined number (4) of the candidate spectra. In the case of doubling, "2") is calculated, the values of the ratios of those four are totaled, and if the total value is sufficiently large, it is judged that the sign has sufficient "signal-likeness". Therefore, it is determined that the code is the signal wave having the maximum signal strength. Specifically, as shown in FIG. 11, the FFT means repeatedly executes the unit FFT (FFT01, FFT02, ..., FFT30, ...), Of which 10 times is one repeating unit (1 pattern FFT). The unit FFT (for example, FFT01 to FFT10) in the number of times for one pattern FFT is selected as the number of times of use), and the spectral values for the signals A, B, C, and D are extracted for each unit FFT. Next, the FFT means, for the first unit FFT (FFT01), the signal strength of the signal C which is the maximum signal strength (1st: 1359.8) and the signal strength of the signal A which is the second signal strength (1st: 1359.8). The ratio (ratio: 2.2) to the 2nd: 610.2) is calculated and held, and the same processing is performed for the other units FFT (FFT02 to FFT10). Next, the FFT means sums the values of the ratios (ratio) of every two unit FFTs for 10 units FFTs (FFT01 to FFT10) and holds them as a total value (sum3). For example, for the first unit FFT (FFT01), the ratio value of the first unit FFT (FFT01) (ratio = 2.2) and the ratio value of the fourth unit FFT (FFT04) (ratio = 1. 2) The ratio value (ratio = 48.6) of the 7th unit FFT (FFT07) and the ratio value (ratio = 30.7) of the 10th unit FFT (FFT10) are summed up and the total value (ratio = 30.7). Sum3 = 82.7) is retained. Similarly, for the second and subsequent unit FFTs (FFT02, FFT03, ..., FFT10), the FFT means also utilizes the subsequent 10 unit FFTs and the ratio of every two unit FFTs. The values of (ratio) are summed and held as a total value (sum3). For example, for the second unit FFT (FFT02), the ratio value of the second unit FFT (FFT02) (ratio = 2.5) and the ratio value of the fifth unit FFT (FFT05) (ratio = 2. 1), the ratio value (ratio = 1.0) of the 8th unit FFT (FFT08), and the ratio value (ratio = 1.7) of the 11th unit FFT (FFT11) are totaled and the total value (ratio = 1.7). Sum3 = 7.4) is retained.

Next, the FFT means compares the total value of the ratios of the respective unit FFTs calculated in this way, and has the total value of the ratio that becomes the maximum compared with the total value of the ratios of the adjacent unit FFTs. Is selected as the candidate unit FFT. As a result, in FIG. 11, for the first 10 units FFT (FFT01 to FFT10), FFT01, FFT04, FFT07, and FFT10 are selected as candidate units FFT ("○" is added to the "selection" column. Has been). For each unit FFT, the sign (A, B, C, D) of the signal wave having the maximum signal strength is entered in the "candidate" column for all unit FFTs, including those that are not candidate unit FFTs. It is displayed (FFT01 = C, FFT02 = C, ..., FFT10 = B). Then, as shown in FIG. 12, the FFT means arranges the symbols (“C”, “C”, “D”, “B” in the case of FIG. 11) in the “candidate” column of each candidate unit FFT in that order. , It is tentatively held as a combination of signal wave codes of the signal wave pattern analyzed by the FFT for the number of FFTs for one pattern (see the "final" column on the left side of the FFT 10 in FIG. 12). The FFT means repeats the above process twice (that is, executes only two trials), holds the results of the two times, and refers to the results of the two times to obtain the most "signal-likeness". The code to be possessed is determined, and the code is adopted as the code for output.

Next, the FFT means has each spectral value (each signal strength) of the four codes (A, B, C, D) extracted for each unit FFT for the section of the delimiter signal E as the unsigned section. ), The unit FFT having the smallest intensity difference (that is, homogenized or leveled) is selected, and it is determined that the signal (signature) belonging to the unit FFT is a delimiter signal, and the unit FFT is used. The code in the "candidate" column is replaced with the code "E" of the delimiter signal. For example, as shown in FIG. 11, when FFT01, FFT04, FFT07, and FFT10 are selected as candidate unit FFTs for the first 10 unit FFTs (FFT01 to FFT10), "candidates" for the four candidate units FFTs. When the continuous value of the code in the column is "CCDB", the intensity ("14.2", "18.4" of the code (A, B, C, D) of the second candidate FFT (FFT04) , "74.4", "61.4") are the group of the most leveled values compared to the other three candidate units FFT, so the FFT means is this second. The code (originally "C") in the "candidate" column of the candidate FFT (FFT04) is replaced with the code "E" of the delimiter signal, and "CEDB" is obtained as the continuous value of the final code (FFT10 in FIG. 12). See the "Final" column on the right side of. Specifically, the FFT means selects the most "unsigned-like" signal output from the four signal outputs as the unsigned period, and at this time, the "unsignedness" is the signal strength of the codes A to D. Based on the ratio of the sum of the above and the one with the highest strength, the one with the lowest strength is selected as unsigned. As described above, in the present invention, it is assumed that repeated signals are emitted from one signal source, and the obtained code is circulated and decoded with the delimited signal (unsigned section) as a guide.

Further, the FFT means independently (simultaneously) obtains the XYZ axis components in the fast Fourier transform process of each signal wave, and obtains the RMS (root mean square) of the obtained complex components for each frequency. Is used as the signal strength. The calculation formula at this time is as follows.
√ (Xr ^ 2 + Xi ^ 2 + Yr ^ 2 + Yi ^ 2 + Zr ^ 2 + Zi ^ 2)
{In the formula, r and i are the real part and the imaginary part, respectively}
This is so that even if there is a change in posture of the receiving side device R such as a mobile communication terminal device, the strength can be calculated without being affected by this.

<Pattern recognition means>
The pattern recognition means 62 is actually output by the transmission side device S based on the spectrum component of each signal wave of the signal wave pattern (corresponding to the signal wave pattern of the transmission side device S) output by the FFT means of the demodulator circuit 61. It recognizes the signal wave pattern. That is, the pattern recognition means 62 recognizes the frequency of each signal wave in the signal wave pattern actually output by the transmitting side device S based on the output signal of the FFT means, and outputs a control signal according to the recognition result. ..

<Matching means>
The matching means 63 inputs a signal from the pattern recognition means 62 and matches the recognition result of the pattern recognition means 62 with a predetermined process, and can be realized, for example, as a configuration using the above software resources. Specifically, the n-ary m-digit information represented by the combination of the signal wave frequencies of the signal wave pattern is used as a specific identifier or code information, and a specific process corresponding to the code information or the like is performed by a computer device. Specific command information to be executed is prepared in association with each different signal wave pattern (for example, stored in a database). Therefore, the matching means 63 is detected by the magnetic sensor 51 (transmitter side device) based on the signal representing the unique code information (corresponding to the combination of the signal wave frequencies of the signal wave pattern) input from the pattern recognition means 62. The signal wave pattern (from S) is matched with specific command information, and the signal corresponding to the matching information is output.

<Command means>
The command means 64 inputs a signal from the matching means 63 and outputs command information corresponding to the signal, and can be realized, for example, as a configuration using the above software resources. For example, the command means 64 can output command information for causing the computer device to execute a specific process based on the matching information from the matching means 63, and in response to the command information, the computer device, for example, can output the command information. , The specific output means 65 can be configured to output predetermined information (video, image, audio, etc.).

[Gist of magnetic communication system]
Based on the above description, the configuration that is the essence of the magnetic communication system according to the present invention will be roughly described. In the magnetic communication system of the present invention including the present embodiment, a predetermined plurality of cases are typically used. A set of signal wave patterns of AC magnetic signals (referred to as "signal wave pattern set" in the present application) is formed by a set (set) of AC magnetic signals having different frequencies continuously, and this signal wave pattern set is formed. Is used as an AC magnetic signal transmitted from the transmitting side device S and an AC magnetic signal received by the receiving side device R. At this time, in this magnetic communication system, the frequency of each AC magnetic signal constituting the signal wave pattern set is set to a different predetermined frequency, and the mutual relationship between the frequencies of the continuous AC magnetic signals in one signal wave pattern set is used. It represents unique information. Then, in the magnetic communication system of the present invention including the present embodiment, the transmitting side device S outputs the AC magnetic signal of a predetermined signal wave pattern output from the magnetic field generation coil 30 under the control of the transmitting side control unit 20 to the receiving side device. R receives by the magnetic sensor 51 and acquires the AC magnetic signal of the signal wave pattern as data. After that, the receiving side control unit 60 of the receiving side device R is determined by the signal wave pattern of the AC magnetic signal output from the magnetic sensor 51 (that is, the combination of the frequencies of the signal waves in each section constituting the signal wave pattern). By recognizing (unique information) and reading it and outputting a predetermined signal corresponding to the signal wave pattern, a computer device is made to execute a predetermined process or the like corresponding to the signal wave pattern.

[Scope of magnetic communication system of the present invention]
Regarding the present invention, examples of use (chairs, desks) as shown in FIGS. 4 and 5 are explained, and a smartphone is exemplified as the receiving side device R (FIG. 4), but the scope of the present invention is limited to the smartphone. A mobile communication terminal device such as a tablet is a typical example, and any communication device is included. Further, the application example of the present invention is not limited to a chair or a desk, and a stationary object (fixing the transmitting side device S) and a moving object (typically a person fixing or carrying the receiving side device R). ) By magnetic communication, it can be applied to any use as long as predetermined information can be exchanged. Further, the control system of the present invention (configuration of circuits and functions of the transmitting side device S and the receiving side device R, etc.) has been described with reference to the example shown in FIG. 6, but the control system of the present invention is not limited thereto. do not have. For example, in the transmitting side device S, an AC waveform (for example, A, B, C, D) having a different frequency is set for the signal wave pattern setting means 21 from the external input device 41 (keyboard, mouse, etc.). Further, by setting patterns of different frequencies (for example, "ABC", "ABD", etc.) and setting a hopping cycle (for example, 0.6 sec) for the hopping cycle setting means 22, a fundamental wave is generated. By modulating the fundamental wave (for example, a 2.4 Hz sinusoidal wave) from the circuit 23 with the modulation circuit 24 according to the signal wave pattern, an alternating current of the signal wave pattern is supplied to the coil drive circuit 25. It has been described that the alternating current generated by the magnetic field generating coil 30 generates an alternating current with the signal wave pattern by feeding the alternating current from the feeding line 26 to the magnetic field generating coil 30, but the control system on the transmitting side is the present invention. Any configuration can be adopted as long as the problem is not impaired and the problem can be achieved. Similarly, in the receiving side device R, the magnetic sensor 51 (built into the mobile communication terminal device or the like) detects the AC magnetic field (AC magnetic signal), and the demodulation circuit 61 demodulates the AC magnetic signal to the AC electricity of the signal wave pattern. After demodulating into a signal, the pattern recognition means 62 recognizes the signal wave pattern, the matching means 63 specifies a predetermined process or operation that matches the signal wave pattern, and the command means 64 performs the predetermined process or the like. Although the description has been described that the command signal corresponding to the operation or the like is output and the output means 65 (display or speaker) outputs the video or audio corresponding to the command signal, the control system on the receiving side is also the present invention. Any configuration can be adopted as long as the problem is not impaired and the problem can be achieved.

Further, in the present invention, the signal wave pattern is not limited to the example of the 3-digit quaternary number as illustrated in the above embodiment, and a configuration using an arbitrary n-ary number with an arbitrary number of digits is possible. be. Further, in the description of the above embodiment, the spectral components of the FFT in FIG. 10 are displayed in a simple spectrum according to the signal wave pattern of FIG. 9 and the timing of the FFT (when only the section of the frequency A is FFTed). Is a schematic explanation of the spectrum of only component A, and in the case of FFT that spans A and B, both components of A and B), but the actual spectrum shows all of ABCD even in the section where FFT does not straddle. Some of the ingredients of are coming out.

In the magnetic communication of the present invention, a normal baseband signal (0 / It is also possible to modulate the carrier wave with (1 bit string), output the AC magnetic signal from the transmitting side device S, and analyze the AC magnetic signal on the receiving side device R side. However, according to the present invention, when an AC magnetic signal is generated by using a signal wave pattern composed of signals having different frequencies and a delimiter signal, communication with less error can be performed. On the other hand, since one of the features of the present invention is to configure a magnetic communication system by using a geomagnetic sensor such as a smartphone originally used as an electronic compass as a magnetic sensor (of the receiving side device R), from this point of view. Also in the present invention, there is a case where the carrier is modulated with a normal baseband signal (0/1 bit string), an AC magnetic signal is output from the transmitting side device S, and the AC magnetic signal is analyzed on the receiving side device R side. It becomes a feature.

Further, in the present invention, a modulation method is adopted in which n different frequencies (for example, four types) are prepared as AC magnetic signals and the frequencies are hopping at a predetermined cycle. By changing, it can be understood that the carrier wave (sine wave) is frequency-modulated (FSK) based on the baseband signal composed of n-ary numbers. Therefore, the present invention can also modulate an n-ary baseband signal by amplitude modulation (ASK) or phase modulation (PSK) (rather than frequency modulation). Further, the present invention employs frequency modulation as a method of preventing erroneous detection even if there is a change in the distance or attitude of the communication terminal device with respect to the magnetic sensor, and demodulates with a high-cost algorithm such as FFT. .. For phase modulation, it is necessary to grasp the characteristics of the magnetic field that can be generated and the FFT tendency in a short sample, but it can be used as the modulation method of the present invention. The most important point is to adopt a modulation method according to the characteristics of the geomagnetic sensor built into smartphones, etc., but since the sample rate on the OS side may differ depending on the model, each such model It is necessary to change the frequency of the signal wave according to the specifications. It is also important to normalize (divide by the value measured at the reference distance) because the sensitivity of the signal differs depending on the frequency. This will vary from individual to individual (because the detection rate will vary significantly with the same correction parameters).

S: Transmitter (transmitter device)
20: Transmitter control unit (transmitter side control means)
21: Signal wave pattern setting means 22: Hopping cycle setting means 24: Modulation circuit 30: Magnetic field generation coil R: Receiver (reception side device)
51: Magnetic sensor 60: Receiver side control unit (receiver side control means)
62: Pattern recognition means 63: Matching means 64: Command means

Claims (5)

It is a magnetic communication system consisting of one transmitting side device and one receiving side device.
The one transmitting device is fixed to one stationary object to be detected, and is fixed to one stationary object.
A transmitting side control unit including a signal wave pattern setting means for generating a signal wave pattern consisting of a predetermined combination of signal waves for uniquely expressing predetermined information, and
It is equipped with a magnetic field generation coil that outputs an AC magnetic signal corresponding to the signal wave pattern.
The signal wave pattern setting means sets n electric signal waves of different frequencies, which are two or more predetermined numbers, and expresses an n-ary number by the n electric signal waves which are the predetermined number, and also expresses the n-ary number. By continuously outputting the electric signal wave of the above by m digits, which is a predetermined number of digits, a function of constructing one signal wave pattern expressing information of n-ary m digits is realized.
The one receiving device is fixed to one moving object and is fixed to one moving object.
A magnetic sensor that detects the AC magnetic signal and
A receiving side control unit for determining the signal wave pattern based on the output of the detection result of the magnetic sensor and determining the unique information expressed by the signal wave pattern is provided.
The frequency of the signal wave constituting the signal wave pattern is set to a frequency in an ultra-low frequency band whose upper limit is 100 Hz or less .
The receiving side control unit receives the output of the magnetic sensor, analyzes the signal wave pattern from the transmitting side device which is the source of the electric signal from the magnetic sensor, and outputs a command signal corresponding to the signal wave pattern. A magnetic communication system characterized by realizing an output function. The magnetic field strength generated by the magnetic field generation coil is usually a normal distance or a range of distances between a stationary object as a detection target and a moving object when the moving object approaches the stationary object. Assuming a distance, the AC magnetic signal from the transmitting side device fixed to the stationary object is restored by the receiving side device fixed to the moving object or moving integrally with the moving object at the normal distance. The magnetic communication system according to claim 1, wherein the strength is set to a strength equal to or higher than the minimum strength value that can be set. The magnetic field strength generated by the magnetic field generation coil is such that when a plurality of stationary objects are two-dimensionally arranged close to each other within a predetermined area range as detection objects, or three-dimensionally close to each other within a predetermined volume range. In the case of According to claim 1 or 2, the intermediate point strength value, which is the maximum value of the magnetic field strength generated by the magnetic field generation coil of the transmitting side device, is set to be less than the minimum strength value. The magnetic communication system described. The magnetic communication system according to claim 2 , wherein the normal distance is set within a distance of 50 cm to 100 cm. The magnetic communication system according to any one of claims 1 to 4, wherein the magnetic sensor is a geomagnetic sensor as a magnetic sensor built in a mobile communication terminal device.

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