JP2011059091A - Apparatus for detecting indoor position - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for detecting an indoor position having high position precision of a terminal device without using any GPSs. <P>SOLUTION: The apparatus for detecting the indoor position 1 includes: a three-axis high-sensitivity magnetic sensor 3 that includes at least three magnetic field generation sources 2 for generating alternate magnetic fields of different frequencies and detects only the alternate magnetic fields disposed within the mobile terminal; a six-axis sensor 4 for detecting an attitude; a means 90 of extracting a magnetic vector 71 for each frequency in a magnetic field generation source 2 of a different frequency from magnetic vector information 70 from the magnetic sensor 3; a means 91 of computing maximum magnetic vector information 72 from the magnetic vector information 71; a coordinate conversion operation means 92 of performing conversion operation of the maximum magnetic vector information 72 to a vertical coordinates system; a means 93 of computing position vector information 74 from the maximum magnetic vector information 73 after the coordinates conversion; a means 94 of computing distance information 75 from the position vector information 74; and a means 95 of computing position information 77 from the distance information 75 and the position information of the magnetic field generation source 2 based on trigonometry. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an indoor position detection device for accurately obtaining the position of an indoor moving body such as a human being in a room.

Conventionally, a system for detecting an outdoor position is known as a global positioning system GPS (Global Positioning System).
However, since the signal from the satellite is weak in the room, there is a problem that it cannot be used.
In order to solve this problem, as a positioning system other than GPS, there is a system that performs positioning using the position of a base station of a communication system such as a mobile phone as disclosed in Patent Document 1. In such a system, if the terminal device can receive signals transmitted from a plurality of base stations, positioning can be performed in a relatively short time even in a room. However, when GPS is used for positioning in a place with poor reception environment such as indoors, even with the configuration as in Patent Document 1, if the strength of the received signal is weak, positioning takes a long time and a large amount of power is required. There was a problem of consumption. Moreover, in the positioning using the position of the base station, the accuracy of the obtained terminal device position is on the order of several hundreds of meters at the most, and there is a problem that it is far from GPS positioning when the conditions are good.

Japanese Patent Laid-Open No. 2004-219076

  Therefore, the present invention provides an indoor position detection device with high position accuracy of a terminal device without using GPS.

  The invention according to claim 1 has at least three magnetic field generation sources that generate alternating magnetic fields having different frequencies from each other, and is placed on a portable terminal that is carried by an indoor moving body. A high-sensitivity magnetic sensor that detects only alternating magnetic vector information in three axial directions orthogonal to each other in a predetermined portable coordinate system, and a geomagnetic sensor that is placed on a portable terminal and detects geomagnetic vector information in the three axial directions From the magnetic vector information detected in the mobile coordinate system of the high-sensitivity magnetic sensor and the magnetic field generation source having a different frequency from the six-axis sensor that detects the gravitational acceleration vector information in the three-axis direction. Each frequency-based magnetic vector information extraction means for extracting magnetic vector information for each frequency, and whether the magnetic vector information for each frequency A maximum magnetic vector information calculation means for calculating maximum magnetic vector information for each frequency, and a maximum magnetic vector information for each frequency detected in the portable coordinate system, which is a coordinate system having a vertical direction as a single axis (hereinafter, vertical A coordinate conversion calculation means for calculating maximum magnetic vector information for each frequency in the vertical coordinate system by performing a conversion calculation using the geomagnetic vector information and the gravitational acceleration vector information in the coordinate system), and the maximum magnetic vector The position vector information calculation means for calculating the position vector information between the magnetic field generation source and the high-sensitivity magnetic sensor from the information, and the position vector information is orthogonally projected onto the horizontal plane, so that the magnetic field generation source on the horizontal plane and the high sensitivity Distance information calculation means for calculating distance information between magnetic sensors, and position information of the magnetic field generation source based on the triangle method from the distance information And position calculating means for calculating a position information on indoor horizontal plane sensitive magnetic sensor using the distance information, a chamber position detecting apparatus comprising a.

  Thereby, a GPS signal is not required, and an indoor position detection device with high positioning accuracy can be obtained.

The invention according to claim 2 has at least three magnetic field generation sources that are installed at the same height in the vertical direction in the room and generate alternating magnetic fields having different frequencies from each other, and is carried by the indoor moving body. A six-axis sensor comprising a geomagnetic sensor for detecting geomagnetic vector information in three axial directions orthogonal to each other in a predetermined portable coordinate system in a portable terminal, and an acceleration sensor for detecting gravitational acceleration vector information in the three axial directions; A high-sensitivity magnetic sensor that detects only AC magnetic vector component information in an arbitrary measurement axis in a portable terminal that is mounted on a terminal and is used at the same height as the magnetic field generation source when used; From the magnetic vector component information of alternating current detected by any one measurement axis of the sensitivity magnetic sensor, each of the magnetic field generation sources having different frequencies is Magnetic vector component information extracting means for each frequency for extracting magnetic vector component information by number, maximum magnetic vector component information calculating means for calculating maximum magnetic vector component information for each frequency from said magnetic vector component information for each frequency, and high The angle formed between the measurement axis and the vertical axis of the sensitivity magnetic sensor is calculated using the geomagnetic vector information and the gravitational acceleration vector information, and the maximum magnetism for each frequency detected by the formed angle and the portable coordinate system. From the vector component information, the vertical axis component information calculating means for calculating the maximum magnetic vector component information for each frequency on the vertical axis whose posture is corrected at the predetermined height, and from the vertical axis component information of the maximum magnetic vector, the magnetic field Distance information calculation means for calculating distance information between the source and the high-sensitivity magnetic sensor, and based on the distance information, three magnetic fields are calculated from the distance information. And position information calculating means for calculating a position information on indoor horizontal surface sensitive magnetic sensor using the positional information and the three distance information sources, an indoor position detecting apparatus comprising a.
Compared to the invention described in claim 1, the present invention provides an indoor position detection device having a simple configuration, no GPS signal, and high positioning accuracy.

  The invention according to claim 3 has at least three magnetic field generation sources that are installed at the same height in the vertical direction in the room and generate alternating magnetic fields having different frequencies from each other, and are carried by the indoor moving body. 6 axes comprising a triaxial magnetic sensor for detecting magnetic vector information in three axial directions orthogonal to each other in a predetermined portable coordinate system in a portable terminal, and a triaxial acceleration sensor for detecting gravitational acceleration vector information in the three axial directions. A high-sensitivity magnetic sensor that detects only AC magnetic vector component information on an arbitrary measurement axis in a portable terminal that is mounted on the portable terminal and is used at substantially the same height as the magnetic field generation source when used. And geomagnetic vector information extracted from the magnetic vector information detected in the portable coordinate system of the three-axis magnetic sensor stored in the microcomputer. Magnetic field information extracting means and magnetic field component information of each frequency of the magnetic field generation source having different frequencies from AC magnetic vector component information detected by an arbitrary measurement axis of the high-sensitivity magnetic sensor stored in the microcomputer. Magnetic vector component information extracting means for each frequency for extracting vector information, maximum magnetic vector component information calculating means for calculating maximum magnetic vector component information for each frequency from said magnetic vector component information for each frequency, and said high-sensitivity magnetic sensor The angle formed by the measurement axis and the vertical axis is calculated using the geomagnetic vector information and the gravitational acceleration vector information, and the maximum magnetic vector component information for each frequency detected in the formed angle and the mobile coordinate system, Vertical axis component information for calculating the maximum magnetic vector component information on the vertical axis whose posture is corrected by frequency at the predetermined height Each of the magnetic field generating sources having different frequencies from the vertical magnetic field component information calculating means of the maximum magnetic vector comprising the calculating means and the magnetic vector information detected in the portable coordinate system of the three-axis magnetic sensor stored in the microcomputer. Magnetic vector information extracting means by frequency for extracting magnetic vector information by frequency, maximum magnetic vector information calculating means for calculating maximum magnetic vector information by frequency from the magnetic vector information by frequency, and detection by the portable coordinate system By converting the calculated maximum magnetic vector information for each frequency into a coordinate system having the vertical direction as one axis (hereinafter referred to as a vertical coordinate system) using the geomagnetic vector information and the gravitational acceleration vector information. A vertical coordinate system comprising: coordinate conversion calculation means for calculating maximum magnetic vector information for each frequency in the vertical coordinate system And storing the maximum magnetic vector vertical axis component information at an arbitrary frequency based on the output from the single-axis high-sensitivity magnetic sensor, and at the same frequency as the maximum magnetic vector vertical axis component information. Vertical axis component information memory means for calculating and storing the vertical axis component information of the maximum magnetic vector information in the vertical coordinate system based on the output of the three-axis magnetic sensor, and the value of the vertical axis component information of the maximum magnetic vector in the vertical coordinate system is When the value is larger than the predetermined value, the first position information calculation means is selected, and when the value of the vertical axis component information of the maximum magnetic vector information in the vertical coordinate system is equal to or less than the predetermined value, the second position information calculation means When the position information calculation selection means and the position information calculation selection means select, any frequency in the vertical coordinate system is selected. The position vector information calculation means for calculating the position vector information between the three-axis magnetic sensor from the magnetic field generation source from the maximum magnetic vector information of the magnetic field, and the position vector information is orthogonally projected onto the horizontal plane, thereby generating the magnetic field on the horizontal plane. A distance information calculation means for calculating distance information between the source and the high-sensitivity magnetic sensor, and based on the distance information, the position information of the magnetic field generation source and the indoor space of the high-sensitivity magnetic sensor based on the distance information Position information calculating means for calculating position information on a horizontal plane of the first position information calculating means, and when selected by the position information calculation selecting means, from the maximum magnetic vector vertical axis component information, Based on the distance information calculating means for calculating the distance information between the sensitive magnetic sensors and the distance information, the position information of the three magnetic field generation sources and the three distance information are calculated based on the triangle method. And position information calculating means for calculating a position information on indoor horizontal plane sensitive magnetic sensor have a second position information computing means composed of a chamber position detecting device characterized by comprising the.

  According to the third aspect of the present invention, even if the portable terminal approaches the magnetic field generation source, the indoor position detection device with high accuracy and a simple configuration that does not require GPS signals and has high positioning accuracy. Is obtained.

In the third aspect of the invention, the magnitude of the maximum magnetic vector information from the triaxial magnetic sensor with respect to the predetermined value with respect to the vertical axis component information is determined. You may judge the magnitude with respect to the predetermined value with respect to the vertical-axis component information of a vector. Basically, the same effect can be achieved.
Which is better is appropriately selected by considering the relationship between the magnetic vector component in the vertical direction and the distance from the magnetic field generation source between the high-sensitivity magnetic sensor and the magnetic sensor.

According to a fourth aspect of the present invention, there is provided an indoor position detection apparatus in which the magnetic field generation source according to the first to third aspects rotates a rare earth sintered magnet using a motor.
Thereby, the installation space | interval of a magnetic field generation source can be extended, and it can be set as a more energy-saving and low-cost apparatus.

According to a fifth aspect of the present invention, in the high-sensitivity magnetic sensor according to the first to fourth aspects, a pulse current is applied to the amorphous wire, and a voltage corresponding to the strength of the surrounding magnetic field is applied to the detection coil wound around the amorphous wire. A magnetic sensor composed of a magnetic impedance element that generates the voltage generated by the detection coil of the magnetic impedance element (hereinafter referred to as MI element as appropriate), and stores the voltage in a hold capacitor via an electronic switch; An indoor position detection device comprising a high-sensitivity magnetic sensor that amplifies only a changing magnetic field signal by connecting a hold capacitor and an amplifier with a high-frequency filter.
As described above, the position detection sensor capable of detecting only the alternating magnetic field is configured as a predetermined electric circuit while using the MI element as described above, thereby detecting the static magnetic field component such as the geomagnetism. Only the changing alternating magnetic field signal from the magnetic field generation source of the invention can be extracted with high sensitivity.

A sixth aspect of the present invention is an indoor position detection apparatus, wherein the frequency of the alternating magnetic field generated by the magnetic field generation source according to the first to fourth aspects is 1 to 40 Hz or 70 to 500 Hz.
When an AC magnetic field signal is generated at a frequency of 1 to 40 Hz, a frequency of 50 to 60 Hz that is normally used in an AC power supply, which is normally present in the room, is avoided, so that only an AC signal having a predetermined frequency is extracted. The noise can be cut by another magnetic vector information extracting means, and only predetermined alternating magnetic vector information can be extracted. In addition, because of the low frequency, it is possible to finally obtain a strong output, thereby enabling highly accurate position detection.
Further, when an alternating magnetic field signal is generated at a frequency of 70 Hz or higher, only the alternating magnetic field signal can be extracted as in the case of 1 to 40 Hz. Moreover, the output decreases as the frequency increases. Since the upper limit of the rotation speed of a normal motor is about 30,000, the frequency of the magnetic field when rotating a rare earth sintered magnet with a normal motor is 500 Hz, but this frequency is also necessary for the indoor position detection device to work. Since an output was obtained, the upper limit of the frequency of the AC magnetic signal was set to 500 Hz.

According to a seventh aspect of the present invention, there is provided an indoor position detecting apparatus, wherein the frequency-specific magnetic vector information extracting means and the maximum magnetic vector information calculating means according to the first or third aspect are Fourier transform means. .
By using the Fourier transform means, AC magnetic vector information of each frequency can be satisfactorily extracted from magnetic vector information in which AC magnetic vector information of each frequency from at least three magnetic field generation sources overlap. At the same time, information proportional to the maximum magnetic vector information can be obtained.

According to an eighth aspect of the present invention, there is provided an indoor position detecting apparatus wherein the frequency-specific magnetic vector component information extracting means and the maximum magnetic vector component information calculating means according to the second or third aspect are Fourier transform means. It is.
By using the Fourier transform means, AC magnetic vector information of each frequency can be satisfactorily extracted from magnetic vector information in which AC magnetic vector information of each frequency from at least three magnetic field generation sources overlap. At the same time, information proportional to the maximum magnetic vector information can be obtained.

According to a ninth aspect of the present invention, there is provided an indoor position detection apparatus wherein the frequency-based magnetic vector information extracting means in the first or third aspect is a digital band filter.
By using the digital band filter, AC magnetic vector information of each frequency can be satisfactorily extracted from magnetic vector information in which AC magnetic vector information of each frequency from at least three magnetic field generation sources overlap.

  According to a ninth aspect of the present invention, there is provided an indoor position detection apparatus wherein the frequency-based magnetic vector information extracting means in the first or third aspect is a digital band filter.

  According to a tenth aspect of the present invention, there is provided the indoor position detecting device, wherein the frequency-specific magnetic vector component information extracting means in the second or third aspect is a digital band filter.

  By using the configuration of the present invention, it is possible to provide an indoor position detection device with high position detection accuracy of a terminal device without using GPS.

  It is a conceptual diagram of the Example of the indoor position detection apparatus of this invention.   It is a conceptual diagram of detection of the magnetic field of the isomagnetic vector distribution and high sensitivity magnetic sensor formed around the magnetic field generation source of the present invention.   It is an electrical circuit diagram of the high sensitivity magnetic sensor used for the indoor position detection apparatus of this invention.   It is a block diagram of the indoor position detection apparatus of Example 1 of the present invention.   It is a block diagram of the indoor position detection apparatus of Example 2 of the present invention.   It is a characteristic figure of the distance from the magnetic field generation source in this invention to a highly sensitive magnetic sensor, and magnetic field intensity.

  Hereinafter, embodiments of the indoor position detection apparatus of the present invention will be described using examples. In addition, this invention is not limited to the following Example.

As shown in FIG. 1, the indoor position detection device 1 includes a magnetic field generation source 2 and a portable terminal 3.
The magnetic generation source 2 includes a magnet 21 and a motor 22. As the magnet 21, an elongated rod-shaped magnet 21 was used. The magnet 21 is magnetized with an N pole on one side and an S pole on the other side. A central portion in the longitudinal direction of the magnet 21 is vertically attached to the end of the motor shaft. Here, as the magnet 21, an Nd—Fe—B based sintered magnet having (BH) max of 38 MGOe was used. The magnet 21 had a diameter of 1 cm and a length of 6 cm.
The motor is attached to an arbitrary position on the wall surface as shown in FIGS. 2, the vertical axis is the vertical axis Z ′ in the earth coordinate system ec in FIG. 1, and the horizontal axis is the northward axis Y ′ in the earth coordinate system ec in FIG. 1. When the motor rotates at a predetermined number of revolutions, a magnetic field as shown by an elliptical line in FIG. 2 is formed around it. The elliptical line is a line indicating the isomagnetic field strength. The thicker the line near the magnet, the stronger the magnetic field strength is near the magnet. 2 is a horizontal plane including the rotation center of the magnetic field source 2 in the direction along the vertical axis Z ′ along the magnetic field of the magnetic sensitive part of the high sensitivity magnetic sensor 4 (circuit is schematically shown) shown in FIG. Above, it was installed at a position in the direction from the magnet center to the north axis. The magnetic field formed by the magnetic field generation source 2 when the motor is rotated at 600 rpm is measured at the above position. As a result, as shown in FIG. 2, the magnetic field strength in the Z′-axis direction oscillates with time, and a 10 Hz sine wave is obtained.

Here, the frequency of the generated alternating magnetic field is preferably 1 to 40 Hz or 70 to 500 Hz. If magnetic signals are generated at these frequencies, the frequency noise of 50-60 Hz used for AC power supply can be cut by frequency-specific magnetic vector extraction means described later, and only predetermined AC magnetic field signals are extracted. it can. Further, in the case of 1 to 40 Hz, since the frequency is low, a strong output can be finally obtained, and thereby highly accurate position detection can be performed. In this example, the frequency of the alternating magnetic field of the three magnetic field generation sources 2 was 8 Hz, 10 Hz, and 12 Hz, respectively.
As shown in FIG. 1, the magnetic field generation source 2 is installed in three places in the room. In the case of FIG. 1, the magnetic field generation sources 2 may be arranged at the four corners of the room.

  The portable terminal 3 is carried or attached to an indoor moving body. Usually, as shown in FIG. 1, the portable terminal 3 is taken by a human hand and used to face the display screen 31. The portable terminal 3 may be carried or attached to an indoor moving body such as an animal or a robot, not limited to a human being. As shown in FIG. 1, the mobile terminal 3 includes a high-sensitivity magnetic sensor 4, a 6-axis sensor 5, and a microcomputer 6 inside.

  As shown in FIG. 1, the high-sensitivity magnetic sensor 4 according to the first embodiment has three magnetic vectors orthogonal to each other in a coordinate system (hereinafter referred to as a portable coordinate system) 3-c that measures predetermined magnetism in a portable terminal. It is necessary to detect each component in the axial direction and to detect only the alternating magnetic vector information 70. In FIG. 1, as an example, the longitudinal direction of the mobile terminal is the Y axis, the right side direction of the display screen of the mobile terminal is the X axis, and the vertical direction to the mobile terminal is the Z axis. In order to detect the three-axis component, three magnetic sensors are required. In the present invention, a sensor using a magnetic impedance element used for the high sensitivity magnetic sensor 4 is used. The MI element is an element that applies a pulse current to an amorphous wire and generates a voltage corresponding to the strength of the surrounding magnetic field in a detection coil wound around the amorphous wire. Amorphous wires that are magnetic bodies of the respective MI elements are installed along the X, Y, and Z axes of the portable coordinate system 3-c of FIG.

The high-sensitivity magnetic sensor 4 used in Example 1 accumulates the voltage generated by the detection coil of the MI element in a hold capacitor via an electronic switch, and connects the hold capacitor and the amplifier with a high frequency filter. Only the fluctuating magnetic field signal is amplified.
The position detection sensor 4 according to the first embodiment does not detect any geomagnetism, which is a DC signal and noise, and can generate a highly sensitive output only for the AC magnetic vector generated by the magnetic source 2. Since the electronic circuit of the sensor of the first embodiment is shown in detail in Japanese Patent Application No. 2006-316273, only the electric circuit diagram is cited and shown in FIG. The high sensitivity magnetic sensor 4 is fixed on a substrate inside the housing of the mobile terminal 3.
In the present invention, the high sensitivity magnetic sensor 4 is used to measure the distance from the magnetic field generation source 2 to the portable terminal 3.

  In the first embodiment, the 6-axis sensor 5 refers to the magnetic vector distribution data measured or calculated based on the earth coordinate system ec described later for the alternating magnetic vector information 70 measured by the portable coordinate system 3-c. Thus, it is used to determine the position of the high sensitivity magnetic sensor. Specifically, the geomagnetic vector information 80a in the triaxial direction and the heavy acceleration vector information 80b in the triaxial direction measured from the six-axis sensor 5 are used to convert the portable coordinate system 3-c to the earth coordinate system ec. , Used to determine the attitude matrix E. The posture detecting 6-axis sensor 5 may be a known 6-axis sensor. The 6-axis sensor is described in, for example, Japanese Unexamined Patent Application Publication No. 2007-93448.

In this publication, the acceleration sensor is a cantilever type, but the three-axis acceleration sensor may be another known acceleration sensor. Here, a capacitance type was used. The triaxial acceleration sensor is used for detecting gravitational acceleration.
As the three-axis magnetic sensor, three MI sensors using MI elements are used for three axes in the present invention. The triaxial magnetic sensor is used to detect the triaxial component of geomagnetism. A Hall element, MR element, or FG sensor may be used instead of the MI element. Further, if the geomagnetism of the three-axis component can be measured, the number of elements may be two.
Usually, the azimuth and orientation can be detected three-dimensionally by the six-axis sensor 5. Here, the posture refers to the pitch, yaw, absolute angle and relative angle of the mobile terminal 3 to which the 6-axis sensor 5 is fixed. In the present invention, the 6-axis sensor 5 is fixed on the same substrate to which the high-sensitivity magnetic sensor 4 inside the housing in the mobile terminal 3 is fixed. Furthermore, it is preferable that the directions of the X, Y, and Z axes of the three-axis sensors are matched. With this arrangement, a posture matrix E, which will be described later, can be easily obtained.

Next, the structure of the microcomputer 6 will be described. As shown in FIG. 1, a microcomputer 6 is incorporated in the portable terminal 3. As shown in FIG. 4, the microcomputer 6 includes a CPU 61, a ROM 62, a RAM 63, an I / O 65, and a connection line 64 for connecting them. The ROM 62 stores a program 62p. When the CPU 61 reads out and executes the program 62p, the frequency-specific magnetic vector information extracting unit 90, the maximum magnetic vector information calculating unit 91, the coordinate conversion calculating unit 92, A position vector information calculation unit 93, a distance information calculation unit 94, a position calculation unit 95, a digital low-pass filter, and the like are realized.
Further, the I / O 65 is connected to the high-sensitivity magnetic sensor 4, the 6-axis sensor 5, and the display device 8 (output means). From the high-sensitivity magnetic sensor 4, AC magnetic vector information 70 in the X, Y, and Z triaxial directions orthogonal to each other of the portable coordinate system 3-c in the portable terminal 3 is input. Further, among the six-axis sensors 5, geomagnetic vector information 80 a is input from the three-axis magnetic sensor 51, and gravitational acceleration vector information 80 b is input from the three-axis acceleration sensor 52. A block diagram of the second embodiment described later is similarly shown in FIG.

<< Magnetic vector information extraction means 90 by frequency >>
The following is the configuration of this embodiment using the program 26p stored in the ROM 62.
The AC magnetic field formed by the magnetic field generation source 2 is detected by the high-sensitivity magnetic sensor 4 as the magnetic vector information 70 of the three-axis component in a state where the AC magnetic fields of three frequencies from the three magnetic field generation sources 2 are overlapped. The frequency-specific magnetic vector extracting means 90 for extracting the alternating magnetic field of each frequency is required.
The frequency-specific magnetic vector extracting means 90 has the following two types of methods and is provided in the microcomputer 6.

The first is a method using a digital bandpass filter 90a. This allows only a predetermined frequency component of the incoming AC signal to pass through.
Specifically, first, magnetic vector information 70 composed of alternating three-axis components formed by overlapping alternating magnetic fields of frequencies including noise is passed to three digital bandpass filters 90a that pass frequencies of 8 Hz, 10 Hz, and 12 Hz, respectively. By passing, it is separated into three magnetic vector information 71 composed of three-axis components having three frequencies.

Another means is a method using Fourier transform means 90b. By using this, the same effect as described above can be obtained.
The operation of the Fourier transform means 90b (hereinafter referred to as FET 90b) will be described. Magnetic vector information 70 in which alternating magnetic fields of respective frequencies overlap is expressed by a time axis and magnetic vector components. The AC signal having the relationship between the time axis and each magnetic vector component is subjected to Fourier transform by the FET 82 to become a signal having a relationship between the frequency and the magnetic vector amplitude (maximum value).
In the present embodiment, peaks are obtained at necessary frequencies of 8, 10, and 12 Hz. An amplitude value is output even at other frequencies. In the present embodiment, the amplitude value at other frequencies is set to 0, and the relationship between the frequency and the magnetic field strength amplitude is subjected to inverse Fourier transform, whereby the three maximum magnetic vector information 71 composed of the three-axis components having three frequencies. Can be separated.
In this case, the Fourier transform means 90b can simultaneously execute the frequency-specific magnetic vector information extraction means 90 and the frequency-specific maximum magnetic vector information calculation means 91 described below. Can be used properly.
By these means, a set of three high-sensitivity magnetic sensors 4 can extract three magnetic vector information 71 from the magnetic field source 2 composed of three-axis components of three different frequencies.

<< Maximum Magnetic Vector Information Calculation Unit 91 by Frequency >>>>
It is necessary to obtain the maximum magnetic vector information 72 for each frequency from the magnetic vector information 71 including the three-axis components for each frequency that changes with time. This is because the maximum magnetic vector information 72 can be uniquely identified, and what is used for a known magnetic vector distribution described later is also the maximum magnetic vector information at each position.
An example of the maximum magnetic vector information calculation means 91 will be described below. First, the absolute value of the magnetic vector information 71 of alternating current at a predetermined time t, which is measured by the portable coordinate system 3-c and passes through the digital band pass filter 90a as the magnetic vector information extracting means 90 by frequency, is calculated.
Then, for example, every time a predetermined time Δt elapses, the absolute value of the magnetic vector signal 71 at that time is calculated and compared with a past absolute value within a predetermined time to obtain a maximum value. The magnetic vector information 72 is read when the maximum value is reached. Thereby, the maximum magnetic vector information 72 for each predetermined frequency detected by the portable coordinate system 3-c can be calculated.

<< Coordinate transformation calculation means 92 of maximum magnetic vector information 72 >>
The coordinate conversion calculation means 92 for the maximum magnetic vector information 72 calculates the maximum in the vertical coordinate system by performing a coordinate conversion calculation on the measurement coordinate system of the maximum magnetic vector information 72 for each frequency from the portable coordinate system to the vertical coordinate system. Magnetic vector information 73 is obtained.
The reason why such coordinate conversion is necessary is that the magnetic field distribution of the method of the present embodiment has a uniform magnetic field intensity distribution line in the cross section including the vertical axis Z ′ of the vertical coordinate system as shown in FIG. On the other hand, if it is not distributed concentrically and the magnitude of the maximum magnetic vector is known, the position between the magnetic field source 2 and the high-sensitivity magnetic sensor cannot be specified, and the position vector (distance) between the two cannot be specified. This is because there are circumstances.
And in order to identify them, the following steps are required. First, the three-dimensional maximum magnetic vector distribution formed by the magnetic field generation source 2 of each frequency in the room is obtained by calculation or measurement with a predetermined measurement coordinate system fixed, and stored in the ROM 62 in advance.
Then, the position of the magnetic vector coinciding with the alternating magnetic vector information 70 measured by the high-sensitivity magnetic sensor 4 for obtaining the three-axis component in the portable terminal 3 is read from the ROM 62 with the already measured three-dimensional maximum magnetic vector distribution data. The position information of the mobile terminal 3 is determined by referring to the call comparison. Then, a position vector (distance) between the position and the magnetic field generation source 2 having position information is obtained in advance.

The problem here is that the measurement coordinate system of the three-dimensional maximum magnetic vector distribution data from the magnetic field generation source 2 is uniquely fixed for reference that is calculated and measured in advance, whereas the portable terminal 3 is basically different from the previous measurement coordinate system. Therefore, even if the maximum magnetic vector measured by the mobile coordinate system 3-c is used, an accurate position can be obtained. It is not.
Therefore, in the present embodiment, the portable coordinate system 3-c, which is the measurement coordinate system of the maximum magnetic vector information 72 for each frequency described above, is subjected to coordinate conversion calculation by rotation to the measurement coordinate system in which the maximum magnetic vector distribution data is measured in advance. (Hereinafter referred to as coordinate transformation calculation means 92). As a result, the coordinate system is matched so that the measurement coordinate systems match, so that it is possible to refer to the maximum magnetic vector data measured in advance that matches the maximum magnetic vector 73, and the mobile terminal 3 (high sensitivity magnetic sensor 4). The position can be specified.

Here, since the room is usually formed on a horizontal plane, it is natural that the measurement coordinate system has at least one vertical axis. (Hereinafter, this coordinate system is referred to as a vertical coordinate system).
In that case, the other two axes can be arbitrarily set on a horizontal plane. In the vertical coordinate system, it is preferable that one axis on the horizontal plane be the north axis as in the earth coordinate system ec in FIG. This is because the coordinate conversion by the coordinate conversion calculation means 92 can be easily performed.
In addition, the vertical coordinate system may be set such that one axis on the horizontal plane is an axis along the wall of the room, as in the room coordinate system rc in FIG. In this case, it is easy for a human to recognize the position on the display screen.
In the first embodiment, the three-dimensional maximum magnetic vector distribution data by the magnetic field generation source 2 for each frequency is calculated or measured in advance in the earth coordinate system ec shown in FIG. It is also possible to provide a so-called heading-up function by using a 6-axis sensor as an electronic compass.

Here, an example of the coordinate transformation calculation means 92 will be described. Among the six-axis sensors 5, geomagnetic vector information 80 a is input from the three-axis magnetic sensor 51 and gravitational acceleration vector information 80 b is input from the three-axis acceleration sensor 52.
Here, in the ideal state, this may be left as it is. However, since the magnetic signal from each magnetic field generation source 2 is placed as noise in the geomagnetic vector information 80a, only a frequency smaller than the minimum frequency to be used is passed. It is preferable to pass through the low-pass filter 920.
Furthermore, noise caused by approaching other magnetic field generation sources in the room can be dealt with by passing only a predetermined frequency through the digital low-pass filter 920.
In addition, since the motion acceleration due to various movements of humans and the like is recorded as noise in the gravitational acceleration vector information 80b, this noise can be dealt with by passing a frequency equal to or lower than a predetermined frequency by the digital low-pass filter 920. .
Such geomagnetic vector information from which various noises have been removed is referred to as geomagnetic vector information 81a, and gravitational acceleration vector information from which various noises have been removed is referred to as gravitational acceleration vector information 81b.

<Attitude Matrix Calculation Means from Geomagnetic Vector Information 81a and Gravity Acceleration Vector Information 81b>
From the geomagnetic vector information 81a and the gravitational acceleration vector information 81b, from a known relational expression, a unit vector facing the east direction in the geography constituting the earth coordinate system, a unit vector facing the north direction, and a unit vector facing the vertical direction are Motomaru. Using these unit vectors, the posture matrix E is obtained. These operations are known means.

<Coordinate transformation calculation means 92 of maximum magnetic vector information 72 by posture matrix E>
The vertical coordinate system is obtained by performing a coordinate conversion operation using the attitude matrix E on the maximum magnetic vector information 72 which has been measured in the portable coordinate system 3-c and passed through the predetermined magnetic vector extracting means for each frequency. The maximum magnetic vector information 73 in the earth coordinate system ec that is one of the above can be obtained.

<< Position vector information calculation means 93 from maximum magnetic vector information 73 after coordinate conversion >>
After that, in the magnetic vector distribution data in the earth coordinate system ec selected as the measurement coordinate system in the alternating magnetic field formed in the room by the known magnetic field generation source 2 stored in the ROM 62, it is obtained earlier. The three-dimensional coordinates having the same magnetic vector as the maximum magnetic vector information 73 after converting the measured coordinate system into the earth coordinate system are referred to. Thereby, a three-dimensional coordinate is obtained. Since the three-dimensional coordinates include an error due to a difference between a known magnetic vector distribution and an actual magnetic vector distribution at the time of measurement, the following means are used to reduce the error.
Position vector information 74 from each magnetic field generation source 2 to the three-dimensional coordinates of the portable terminal 3 (high sensitivity magnetic sensor 4) is obtained (hereinafter referred to as position vector information calculation means 93).

<< Distance information calculation means 94 >>
Further, an orthogonal projection vector onto the horizontal plane of the three position vector information 74 is obtained. The distance information 75 from each magnetic field generation source 2 to the portable terminal is calculated from the length of each orthogonal projection vector (hereinafter referred to as distance information calculation means 94).

<< Position calculation means 95 based on trigonometry >>
From the position information 76 of the three magnetic field generation sources 2 and the three distance information 75 from the three magnetic field generation sources 2 to the portable terminal 3, the portable terminal 3 (high-sensitivity magnetic field) on the horizontal plane in the room is based on trigonometry. The position information 77 of the sensor 4) is calculated two-dimensionally (hereinafter referred to as position calculation means 95) and specified.

  As shown in FIG. 3, the display device 10 is connected to the microcomputer 6, and the position information on the horizontal plane in the room of the mobile terminal 3 is displayed on the display screen of the mobile terminal 3 in FIG. 1 using the display device 10. 31. Each means shown here is an example and is not limited thereto.

  In the second embodiment, the AC magnetic field vector from the magnetic field generation source 2 is measured using a high-sensitivity magnetic sensor 4 to measure the three-axis component, but only the vertical axis magnetic vector is specified. The position of the portable terminal 3 in the room is to be detected by measuring a magnetic vector with a uniaxial high-sensitivity magnetic sensor 4 on a horizontal plane. This apparatus used the same magnetic field generation source 2 as in Example 1 at a predetermined height. The alternating magnetic field generated from the magnet body 21 has only a vertical component Hz 'that is the Z' axis in FIG. 1 on a horizontal plane at the same predetermined height. The present embodiment is a technique that utilizes the property of magnetic field distribution that the distribution of the equal magnetic field strength consisting of the absolute value of the maximum magnetic vector is formed concentrically from the magnet on the horizontal plane. The feature of the second embodiment is that if the mobile terminal 3 is used on a horizontal plane having the same height as the installation position of the magnetic field generation source 2 and an alternating magnetic field vector consisting only of the vertical direction on the horizontal plane can be accurately measured, the magnetic field strength and distance The distance information on the horizontal plane between the magnetic field generation source 2 and the portable terminal can be easily obtained from the function of Here, only the changed part from Example 1 is described, and the overlapping part is omitted.

First, the hardware changes from the first embodiment will be described.
In this embodiment, the magnetic field generation source 2 is attached to a wall surface having a height of 1 m from the floor. The reason why the attachment position is set to about 1 m from the floor is that when a human uses the mobile terminal, the position of the mobile terminal is about 1 m from the floor.
In the high-sensitivity magnetic sensor 4 of the present embodiment, since the mobile terminal 3 is used in a region near a height of 1 m, the measurement target magnetic field vector is only in the vertical axis Z ′ direction. For this reason, only one high-sensitivity magnetic sensor 4 is required as long as it can measure an arbitrary one-axis direction.

  Next, changes in software from Example 1 will be described. The software means of the first embodiment includes a frequency-specific magnetic vector information extracting means 90, a maximum magnetic vector information calculating means 91, a coordinate transformation calculating means 92, a position vector information calculating means 93, a distance information calculating means 94, and a position information calculating means 95. Among them, since the maximum magnetic vector information calculation means 91, the coordinate conversion calculation means 93, and the distance calculation means 94 are different, an example of specific means will be shown mainly.

  Similarly to the first embodiment, the frequency-based magnetic vector component information extraction unit 900 uses the magnetic vector information of any one axis component detected from any one measurement axis of the portable coordinate system 3-c from the high-sensitivity magnetic sensor 4. From 700, magnetic vector information 701 of one-axis component for each frequency of the magnetic field generation source 2 having different frequencies is extracted. The measurement axis of the sensor may be in any direction, but in order to simplify subsequent calculations, here, measurement was performed on the Y axis of the portable coordinate system 3-c (longitudinal direction of the portable terminal 3 in FIG. 1).

<< Maximum Magnetic Vector Information Calculation Unit 901 >>
Here, the maximum magnetic vector information calculating means 901 for calculating the maximum magnetic vector information 702 for each frequency from the magnetic vector information for each frequency 701 will be described. Since the magnetic vector information 701 composed of the Y-axis component of the portable coordinate system 3-c changes with time at each frequency, it is necessary to obtain the maximum magnetic vector information 702 as in the first embodiment.
An example of the maximum magnetic vector information calculation unit 901 will be described below. First, the absolute value of the magnetic vector information 701 of the uniaxial component of the alternating current at the predetermined time t for each frequency is calculated by measuring on the Y axis of the portable coordinate system 3-c.
Then, every time the predetermined time Δt elapses, the absolute value of the magnetic vector information 701 at that time is calculated, and the maximum value of the absolute value within a certain time is obtained. The magnetic vector information 702 at the time when the maximum value is reached is read. Thereby, it is possible to calculate the maximum magnetic vector information 702 of the one-axis component for each predetermined frequency measured on the Y-axis.

<< Maximum Magnetic Vector Component Vertical Axis Component Information Calculation Unit 902 >>
The maximum magnetic vector component information calculation means 902 calculates the angle formed by the measurement axis of the high-sensitivity magnetic sensor 4 and the vertical axis, and the frequency at a predetermined height is calculated from the formed angle and the maximum magnetic vector information 702 for each frequency. The vertical axis component information 703 of another maximum magnetic vector component is calculated.
In the second embodiment, since the AC magnetic field is not measured with three axes, coordinate conversion using the posture matrix E as in the first embodiment is difficult to perform. Therefore, one measurement axis of the high-sensitivity magnetic sensor 4 using the geomagnetic vector information 81a and the gravitational acceleration vector information 81b obtained by removing various noises from the geomagnetic vector information 80a and the gravitational acceleration vector information 80b from the six-axis sensor 5. The angle formed by the Y axis and the vertically downward magnetic vector formed by the magnetic field generation source 2 having a predetermined frequency at the position of the mobile terminal 3 at a height of 1 m is calculated by a known relational expression.
The vertical axis component information 703 of the maximum magnetic vector component is calculated from a known relational expression using the one-axis maximum magnetic vector information 702 in the portable coordinate system and the angle formed previously (hereinafter referred to as the maximum magnetic vector component). Vertical axis component information calculation means 902).

<< Distance information calculation means 903 >>
The distance information calculation means 903 calculates distance information 704 between the magnetic field generation source 2 and the high sensitivity magnetic sensor 4 using the maximum magnetic field strength information 703.
As described above, the absolute value of the magnetic field vector pointing in the vertical direction on the horizontal plane at the same height by the AC magnetic field generated by the magnetic field source 2 having a height of 1 m is expressed as a function of the distance r from the magnet center. .
Therefore, by substituting the absolute value of the maximum magnetic vector 73 obtained previously into the above function, the two-dimensional on the horizontal plane from the respective magnetic field generation sources 2 to the high-sensitivity magnetic sensor 4 (mobile terminal 3). Distance information 704 is obtained. For this reason, the apparatus of this embodiment omits two high-sensitivity magnetic sensors 4 and does not require a device corresponding to the position vector information calculation means 93 of the first embodiment.

<< Position performance information calculation means 904 >>
As in the first embodiment, the position information calculation unit 904 uses the position information 705 of the three magnetic field generation sources and the three distance information 704 on the horizontal plane in the room of the high sensitivity magnetic sensor 4 based on the triangle method. The position information 706 is calculated. From the three distances from the three magnetic field generation sources 2 on the horizontal plane at a position 1 m from the floor to the mobile terminal 3, the position of the mobile terminal on the horizontal plane is specified two-dimensionally by trigonometry.

  Further, as shown in FIG. 3, a display device 8 is connected to the microcomputer 6, and the position information on the horizontal plane in the room of the portable terminal 3 is displayed on the display screen of the portable terminal 3 of FIG. 1 using the display device 8. To display.

In the case of the present Example 2, the magnetic field generation source 2 is attached to the wall surface with a height of 1 m from the floor. A magnet center is set on a horizontal plane having a height of 1 m from the floor, and a straight line perpendicular to the rotation surface of the magnet is assumed from the magnet center. The magnetic field strength of the alternating magnetic vector originally only in the vertical direction measured by the high-sensitivity magnetic sensor 4 installed in the vertical direction at an arbitrary distance from the magnet center on the straight line and at an arbitrary distance on the straight line The relationship is shown in FIG. The magnetic field generation source 2 is the same as that of the first embodiment, and an elongated rod-shaped magnet is rotated along the wall surface.
The same high-sensitivity magnetic sensor 4 as in Example 1 detected a 10 nT magnetic field strength at a point 6 m from the magnetic source 2. It can be seen that a magnetic field strength difference of 10 nT is given in the vicinity of 5 m from the magnetic source 2 with respect to the change of the distance 1 m. Since the high sensitivity magnetic sensor 4 has a magnetic resolution of at least 0.5 nT, the position resolution of the position detection sensor has a high performance of 50 mm. When using the original high-sensitivity magnetic sensor, since the noise magnetic field in the room is 3 to 4 nT, the installation interval between the magnetic field generation sources 2 is preferably about 5 m. These installation intervals can be increased to 10 m or more by increasing sensor sensitivity or the like.

  In the third embodiment, distance information is obtained from magnetic vector information obtained from a triaxial magnetic sensor having relatively low sensitivity at a relatively short distance as a sensor for measuring distance, and uniaxial high-sensitivity magnetism is obtained at a distance farther than that. By finding distance information by simple measurement using a sensor, the indoor position detection device can obtain sufficient measurement accuracy with a simple configuration even in applications where there is a certain amount of position variation in the height direction of the mobile terminal. In the present embodiment, as in the second embodiment, the alternating magnetic field generated from the magnet body 21 has a vertical direction component Bz ′ that is the Z ′ axis in FIG. 1 on the horizontal plane at the same predetermined height. Only the vertical direction component Bz ′ of the magnetic vector at the position of the high-sensitivity magnetic sensor 51 and the distance from the magnetic field generation source to the position of the high-sensitivity magnetic sensor 51 are used. Also in the third embodiment, the mobile terminal 3 is used on a horizontal plane having the same height as the installation position of the magnetic field generation source 2. Here, only the changed part from Example 1 is described, and the overlapping part is omitted.

Specifically, the magnetic field generation source 2 is all attached to a wall surface having a height of 1 m in the vertical direction as in the second embodiment, and other specifications relating to the magnetic field generation source are as in the first embodiment. Same as 2.
In this embodiment, the indoor moving body is a robot. The 6-axis sensor is the same as that of the first embodiment, and the high-sensitivity magnetic sensor 4 is the same as that of the first embodiment.

The geomagnetic vector extraction means for extracting the geomagnetic vector information from the magnetic vector information detected by the portable coordinate system of the three-axis magnetic sensor 51 stored in the microcomputer 6 is digital as in the first embodiment as in 0036. A low pass filter 920 was used.
Further, as in the case of 0036, the digital low-pass filter was used for noise such as motion acceleration with respect to the triaxial acceleration sensor, as in 0036.

<< Maximum Magnetic Vector Component Vertical Axis Component Information Calculation Unit 1000 >>
The maximum magnetic vector for obtaining the vertical axis component information 703 of the maximum magnetic vector component from the alternating magnetic vector component information 700 detected by any one measurement axis of the one axis high-sensitivity magnetic sensor 4 stored in the microcomputer 6 The component vertical axis component information calculation means 1000 is a frequency-specific magnetic vector component information extraction means 900, maximum magnetic vector information calculation means 901, and vertical axis component information calculation of the maximum magnetic vector component shown in 0046 to 0048 of the second embodiment. This is the same as the step of the means 902.

<< Maximum Magnetic Vector Information Calculation Unit 1100 in Vertical Coordinate System (Earth Coordinate System) >>
The maximum in the earth coordinate system ec for obtaining the maximum magnetic vector information 73 in the earth coordinate system ec from the magnetic vector information 70 detected in the portable coordinate system 3-c of the three-axis magnetic sensor 51 stored in the microcomputer 6 The magnetic vector information calculation means 1100 includes the frequency-specific magnetic vector information extraction means 90, the frequency-specific maximum magnetic vector information calculation means 91, and the coordinates of the maximum magnetic vector information 72 shown in 0029 to 0032 and 0036 to 0038 of the first embodiment. This is the same as the step of the conversion calculation means 92.

<< Vertical Axis Component Information Memory Means 1200 >>
The vertical axis component information memory means 1200 stores the vertical axis component information 703 of the maximum magnetic vector component at an arbitrary frequency based on the output from the uniaxial high-sensitivity magnetic sensor 4, and the vertical axis component information 703 of the maximum magnetic vector. The vertical axis component information 73 ′ of the maximum magnetic vector information 73 in the earth coordinate system based on the output of the three-axis magnetic sensor 51 at the same frequency is calculated and stored in the ROM 62 of the microcomputer 6.

<< Position Information Calculation Selection Unit 1300 >>
When the value of the vertical axis component information 73 ′ of the maximum magnetic vector in the earth coordinate system ec is larger than a predetermined value, the position information calculation selection unit 1300, which is a feature of the present embodiment, is described below. The position information calculation means 1400 is selected, and if the value of the vertical axis component information 73 ′ of the maximum magnetic vector information in the earth coordinate system ec is equal to or less than a predetermined value, the second position information calculation means 1500 is selected.
Here, the predetermined value is 500 nT. If the value of the vertical axis component information 73 ′ of the maximum magnetic vector information is greater than 500 nT, the distance from the magnetic field generation source 2 at which sufficient sensitivity can be obtained in the three-axis magnetic sensor 51 made of the MI sensor. This corresponds to the distance at which the rotation of the magnetic vector starts to increase due to the displacement in the vertical direction from the horizontal plane including. In this embodiment, the distance from the magnetic field generation source 2 is about 2 m. Therefore, the first position information calculation means 1400 that uses the three-axis magnetic sensor 51 that measures magnetic vector information is selected.
Conversely, if the value of the vertical axis component information 73 ′ of the maximum magnetic vector information is 500 nT or less, the distance from the magnetic field generation source 2 at which sufficient sensitivity cannot be obtained with the three-axis magnetic sensor 51 made of the MI sensor. The distance from the horizontal plane including the magnetic field generation source 2 is almost no rotation of the magnetic vector due to the vertical displacement. Therefore, the second position information calculation means 1500 that uses a uniaxial magnetic vector component in the high-sensitivity magnetic sensor 4 having sufficient sensitivity at that distance is selected.

<< first position information calculation means 1400 >>
When selected by the position information calculation selection means 1300, the first position information calculation means 1400 that obtains the position information 77 of the portable terminal 3 on the horizontal plane from the maximum magnetic vector information 73 of an arbitrary frequency in the earth coordinate system ec. The steps of the position vector information calculation means 93, the distance information calculation means 94, and the position calculation means 95 based on trigonometry shown in 0039 to 0041 of the first embodiment are the same.

<< Second position information calculation means 1500 >>
The second position information calculation unit 1500 that obtains the position information 706 of the portable terminal 3 on the horizontal plane from the vertical axis component information 703 of the maximum magnetic vector component when selected by the position information calculation selection unit 1300 is the same as that of the second embodiment. The steps of the distance information calculation means 903 and the position performance information calculation means 904 shown in FIG.

The equal maximum magnetic vector distribution in the vertical axis Z ′ direction of the second embodiment is, as can be seen from the schematic diagram of FIG. 2, the closer the distance from the magnetic field generation source is, the smaller the sensor position deviates from the magnet installation height. Then, the deviation of the direction of the magnetic vector at that point from the vertical direction becomes large, and the error based on the positional deviation of the highly sensitive magnetic sensor in the vertical direction may increase. On the other hand, if the distance is some distance away, even if the position slightly deviates from the magnet installation height, the direction of the magnetic vector remains in the vertical direction in the vicinity.
By utilizing this fact, in this embodiment, the magnetic vector is obtained by the triaxial magnetic sensor 51 in an area where the distance is close to some extent and the measurement of the inclination of the magnetic vector is necessary. Here, the reason why the three-axis high-sensitivity magnetic sensor 4 is not required is that a sufficient signal can be obtained even if the sensor sensitivity is relatively low because the distance from the magnetic field generation source to the sensor is short. Thereafter, the maximum magnetic vector information 73 in the earth coordinate system is calculated using the triaxial magnetic sensor 51 in the same manner as in the first embodiment. Thereafter, the vertical axis component information 73 ′ of the maximum magnetic vector information is calculated from the information as described above.
On the contrary, a uniaxial high-sensitivity magnetic sensor was used because it was not necessary to measure the gradient of the magnetic vector in a sufficiently distant area. Thereafter, as in the second embodiment, the vertical axis component information 703 of the maximum magnetic vector component is calculated based on the high-sensitivity magnetic sensor 4 with one axis.

In this embodiment, it is determined whether the vertical axis component information 73 ′ of the maximum magnetic vector information in the earth coordinate system from the three-axis magnetic sensor 51 is larger or smaller than a predetermined value. If the value is larger than the predetermined value, it is determined that the distance between the sensor (mobile terminal 3) and the magnetic field generation source 2 is short and the value from the triaxial magnetic sensor 51 can be used, and the earth coordinate system from the triaxial magnetic sensor 51 is used. The position information 77 is calculated by the first position information calculation means 1400 using the maximum magnetic vector information 73 of an arbitrary frequency at ec.
If it is equal to or less than the predetermined value, it is determined that the distance between the sensor (mobile terminal 3) and the magnetic field generation source 2 is too long to use the triaxial sensor 51, and the maximum magnetic vector from the uniaxial high-sensitivity magnetic sensor 4 is determined. The position information 706 is calculated by the second position information calculation means 1500 using the component vertical axis component information 703.
As a result, in applications in which the position in the height direction of the portable terminal carried with the movement of the robot changes, in Example 2, the measurement accuracy of the uniaxial high-sensitivity magnetic sensor decreases as the magnetic field generation source is approached. However, by configuring as in the third embodiment, even if the portable terminal approaches the magnetic field generation source, the GPS signal is not required with high accuracy and a simple configuration, and is high. An indoor position detection device with positioning accuracy can be obtained.

In Example 3, the magnitude of the maximum magnetic vector information from the three-axis magnetic sensor 51 with respect to the predetermined value with respect to the vertical axis component information 73 ′ is determined, but the maximum magnetism from the single-axis high-sensitivity magnetic sensor 4 is determined. You may determine the magnitude | size with the predetermined value with respect to the vertical-axis component information 703 of a vector component.
If the value is larger than the predetermined value, it is determined that the distance between the sensor (mobile terminal 3) and the magnetic field generation source 2 is short and the value from the triaxial magnetic sensor 51 can be used, and the earth coordinate system from the triaxial magnetic sensor 51 is used. The position information is calculated by the first position information calculation means using the maximum magnetic vector information 73 of an arbitrary frequency at ec. If the value is equal to or smaller than the predetermined value, it is determined that the distance between the sensor (mobile terminal 3) and the magnetic field generation source 2 is too long to use the triaxial magnetic sensor 51, and the maximum magnetism from the uniaxial high sensitivity magnetic sensor 4 is determined. The position information is calculated by the second position information calculation means using the vertical axis component information 703 of the vector component. Basically, the same effect can be achieved.
Which is better is appropriately selected depending on the relationship between the magnetic vector component in the vertical direction and the distance from the magnetic field generation source between the high-sensitivity magnetic sensor and the magnetic sensor.

1: Indoor position detection device 2: Magnetic field generation source 3: Mobile terminal 4: High-sensitivity magnetic sensor 5: 6-axis sensor 51: 3-axis magnetic sensor 52: 3-axis acceleration sensor 6: Microcomputer 90: Magnetic vector information extraction means by frequency 91: Maximum magnetic vector information calculation means for each frequency 92: Coordinate conversion means for maximum magnetic vector information 90a: Digital low-pass filter 90b: Fourier transform means 93: Position vector information calculation means 94: Distance information calculation means 95: Based on trigonometry Position computing means 900: frequency-specific magnetic vector component information extracting means 901: maximum magnetic vector information computing means 902: vertical axis component information computing means 903 for maximum magnetic vector components: distance information computing means 904: position performance information computing means 920: digital Low-pass filter 1000: Vertical axis component information operator of maximum magnetic vector component 1100: Vertical coordinate system maximum magnetic vector information calculation unit in the (global coordinate system) 1200: Vertical axis component information memory means 1300: position information computation selection unit 1400: first position information calculation means 1500: second position information calculating means

Claims (10)

Having at least three magnetic field generation sources that generate alternating magnetic fields having different frequencies from each other, installed in a room,
A high-sensitivity magnetic sensor that is mounted on a portable terminal carried by the indoor moving body and detects only alternating magnetic vector information in three axial directions orthogonal to each other in a predetermined portable coordinate system in the portable terminal;
A 6-axis sensor mounted on a portable terminal and comprising a geomagnetic sensor for detecting geomagnetic vector information in the three-axis direction and an acceleration sensor for detecting gravitational acceleration vector information in the three-axis direction;
Frequency-specific magnetic vector information extraction means for extracting magnetic vector information for each frequency of the magnetic field generation source having a different frequency from magnetic vector information detected in the portable coordinate system of the high-sensitivity magnetic sensor;
Maximum magnetic vector information calculation means for calculating maximum magnetic vector information by frequency from the magnetic vector information by frequency,
Using the geomagnetic vector information and the gravitational acceleration vector information for the maximum magnetic vector information for each frequency detected in the portable coordinate system in a coordinate system having a vertical direction as one axis (hereinafter referred to as a vertical coordinate system). Coordinate conversion calculation means for calculating the maximum magnetic vector information for each frequency in the vertical coordinate system,
From the maximum magnetic vector information, position vector information calculation means for calculating position vector information between the magnetic field generation source and the high-sensitivity magnetic sensor;
Distance information calculation means for calculating distance information between the magnetic field generation source on the horizontal plane and the high-sensitivity magnetic sensor by orthogonally projecting the position vector information onto the horizontal plane;
Indoor position detection comprising: position information means for calculating position information on the horizontal plane of the room of the high sensitivity magnetic sensor using the distance information and the position information of the magnetic field generation source based on the triangle method from the distance information apparatus The room has at least three magnetic field generation sources that are installed at the same height in the vertical direction and generate alternating magnetic fields having different frequencies from each other,
From a geomagnetic sensor for detecting geomagnetic vector information in three axial directions orthogonal to each other in a predetermined portable coordinate system in a portable terminal carried by the indoor moving body, and an acceleration sensor for detecting gravitational acceleration vector information in the three axial directions 6-axis sensor
A high-sensitivity magnetic sensor that detects only AC magnetic vector component information in an arbitrary measurement axis in a portable terminal that is mounted on a portable terminal and is used at substantially the same height as the magnetic field generation source when used;
Frequency-specific magnetic vector component information for extracting magnetic vector component information for each frequency of the magnetic field generation source having different frequencies from AC magnetic vector component information detected by any one measurement axis of the high-sensitivity magnetic sensor Extraction means;
Maximum magnetic vector component information calculation means for calculating maximum magnetic vector component information by frequency from the magnetic vector component information by frequency,
The angle formed between the measurement axis and the vertical axis of the high-sensitivity magnetic sensor is calculated using the geomagnetic vector information and the gravitational acceleration vector information, and the maximum angle for each frequency detected in the portable coordinate system and the formed angle. From the magnetic vector component information, vertical axis component information calculating means for calculating maximum magnetic vector component information for each frequency on the vertical axis whose posture is corrected at the predetermined height;
From the vertical axis component information of the maximum magnetic vector, distance information calculation means for calculating distance information between the magnetic field generation source and the high-sensitivity magnetic sensor;
From the distance information, based on the triangle method, position information calculation means for calculating position information on the horizontal plane in the room of the highly sensitive magnetic sensor using the position information of the three magnetic field generation sources and the three distance information;
Indoor position detection device comprising The room has at least three magnetic field generation sources that are installed at the same height in the vertical direction and generate alternating magnetic fields having different frequencies from each other,
A triaxial magnetic sensor for detecting magnetic vector information in three axial directions orthogonal to each other in a predetermined portable coordinate system in a portable terminal carried by the indoor moving body, and three axes for detecting gravitational acceleration vector information in the three axial directions A 6-axis sensor comprising an acceleration sensor;
A high-sensitivity magnetic sensor that detects only AC magnetic vector component information in an arbitrary measurement axis in a portable terminal that is mounted on a portable terminal and is used at substantially the same height as the magnetic field generation source when used;
Geomagnetic vector information extracting means for extracting geomagnetic vector information from magnetic vector information detected in the portable coordinate system of the three-axis magnetic sensor stored in a microcomputer;
The frequency-specific magnetic vector information of each magnetic field generation source having a different frequency is extracted from the alternating magnetic vector component information detected by any one measurement axis of the high-sensitivity magnetic sensor stored in the microcomputer. Magnetic vector component information extraction means;
Maximum magnetic vector component information calculation means for calculating maximum magnetic vector component information by frequency from the magnetic vector component information by frequency,
The angle formed between the measurement axis and the vertical axis of the high-sensitivity magnetic sensor is calculated using the geomagnetic vector information and the gravitational acceleration vector information, and the maximum angle for each frequency detected in the portable coordinate system is determined. Vertical axis component information calculation of the maximum magnetic vector component comprising the vertical axis component information calculation means for calculating the maximum magnetic vector component information on the vertical axis corrected by the posture for each frequency at the predetermined height from the magnetic vector component information Means,
Frequency-based magnetic vector information extraction means for extracting magnetic vector information for each frequency of the magnetic field generation source having different frequencies from magnetic vector information detected in the portable coordinate system of the three-axis magnetic sensor stored in the microcomputer; ,
Maximum magnetic vector information calculation means for calculating maximum magnetic vector information by frequency from the magnetic vector information by frequency,
Using the geomagnetic vector information and the gravitational acceleration vector information for the maximum magnetic vector information for each frequency detected in the portable coordinate system in a coordinate system having a vertical direction as one axis (hereinafter referred to as a vertical coordinate system). A coordinate conversion calculation means for calculating the maximum magnetic vector information for each frequency in the vertical coordinate system, and a maximum magnetic vector information calculation means in the vertical coordinate system,
The maximum magnetic vector vertical axis component information at an arbitrary frequency based on the output from the one-axis high-sensitivity magnetic sensor is stored, and the vertical based on the output of the three-axis magnetic sensor at the same frequency as the maximum magnetic vector vertical axis component information is stored. Vertical axis component information memory means for calculating and storing vertical axis component information of maximum magnetic vector information in the coordinate system;
When the value of the vertical axis component information of the maximum magnetic vector in the vertical coordinate system is larger than a predetermined value, the first position information calculation means is selected, and the vertical axis component information of the maximum magnetic vector information in the vertical coordinate system is selected. A position information calculation selection means for selecting the second position information calculation means when the value is equal to or less than a predetermined value;
Position vector information calculating means for calculating position vector information between the three-axis magnetic sensor from the magnetic field generation source from the maximum magnetic vector information of an arbitrary frequency in the vertical coordinate system when selected by the position information calculation selecting means;
Distance information calculation means for calculating distance information between the magnetic field generation source on the horizontal plane and the high-sensitivity magnetic sensor by orthogonally projecting the position vector information onto the horizontal plane;
Based on the distance information, based on the triangle method, the position calculation means for calculating the position information on the horizontal plane in the room of the high sensitivity magnetic sensor using the distance information and the distance information. Information computing means;
Distance information calculation means for calculating distance information between the magnetic field generation source and the high-sensitivity magnetic sensor from the maximum magnetic vector vertical axis component information when selected by the position information calculation selection means;
From the distance information, based on the triangle method, position information calculation means for calculating position information on the horizontal plane in the room of the highly sensitive magnetic sensor using the position information of the three magnetic field generation sources and the three distance information; Second position information calculation means comprising:
An indoor position detecting device comprising:   The indoor position detection apparatus according to claim 1, wherein the magnetic field generation source rotates a rare earth sintered magnet using a motor.   The high-sensitivity magnetic sensor includes a magnetic impedance element that applies a pulse current to an amorphous wire and generates a voltage corresponding to a magnetic field strength around the detection coil wound around the amorphous wire. It comprises a high-sensitivity magnetic sensor that amplifies only a magnetic field signal that fluctuates by accumulating the voltage generated by the detection coil in a hold capacitor via an electronic switch and connecting the hold capacitor and an amplifier with a high-frequency filter. The indoor position detection device according to claim 1-4,   The indoor position detection device according to claim 1, wherein the frequency of the alternating magnetic field generated by the magnetic field generation source is 1 to 40 Hz or 70 to 500 Hz.   4. The indoor position detecting device according to claim 1, wherein the frequency-specific magnetic vector information extracting means and the maximum magnetic vector information calculating means are Fourier transform means.   The indoor position detecting device according to claim 2 or 3, wherein the frequency-based magnetic vector component information extracting means and the maximum magnetic vector component information calculating means are Fourier transform means.   4. The indoor position detecting device according to claim 1, wherein the frequency-based magnetic vector information extracting means is a digital band filter.   The indoor position detecting device according to claim 2 or 3, wherein the frequency-based magnetic vector component information extracting means is a digital band filter.

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