JP7664305B2 - Spatial magnetic field measuring system and spatial magnetic field measuring method - Google Patents

Description

Article 30, paragraph 2 of the Patent Act applies. Exhibited on September 14, 2022 at the "JIMA 2022 11th General Inspection Equipment Exhibition" held at Tokyo Big Sight (held from September 14 to 16, 2022). Exhibited on October 26, 2022 at the "5th Nagoya EV/HV/FCV Technology Exhibition (within Nagoya Automotive World 2022)" held at Port Messe Nagoya (held from October 26 to 28, 2022). Exhibited on January 25, 2023 at the "15th EV/HV/FCV Technology Exhibition (within Automotive World 2023)" held at Tokyo Big Sight (held from January 25 to 27, 2023).

The present invention relates to a spatial magnetic field measurement system and a spatial magnetic field measurement method.

Spatial magnetic field measuring devices are used to measure and visualize the magnetic field distribution in the three-dimensional space around an object, in order to measure the magnetic fields generated by products such as electronic devices and identify noise sources and analyze magnetic interference.

Such a spatial magnetic field measuring device can be realized by measuring the correspondence data between the magnetic field and position coordinates at each measurement position in three-dimensional space, for example, by scanning a magnetic probe with a movable XYZ stage as in Patent Document 1, or by moving the magnetic probe three-dimensionally with a robot arm. However, these methods are limited by the size and range of motion of the XYZ stage and robot arm, and therefore the device must be made larger in size depending on the size of the object to be measured, preventing weight reduction, space saving, and cost reduction.

In response to this, for example, the conventional techniques of Patent Documents 2 to 4 disclose spatial magnetic field measuring devices in which a magnetic probe is manually scanned. More specifically, in the conventional techniques disclosed in Patent Documents 2 to 4, the magnetic probe is manually scanned around the space surrounding the object to be measured, and a camera is used to capture an image of the object to be measured and the magnetic probe being scanned, and the spatial magnetic field is measured using corresponding data between the measurement position and angle of the magnetic probe calculated from the image and the magnetic field measured at that timing.

JP 2010-190709 A JP 2013-238581 A International Publication No. 2009/028186 International Publication No. 2014/002466

However, in the above conventional technology, the preparation for magnetic measurement is burdensome, as it requires predefining the movable area of the magnetic probe to identify the position coordinates and angle of the magnetic probe, and setting the camera so that the movable area falls within the angle of view. In addition, when the measurement target is, for example, the inside of a steel pipe or has a complex shape, it may not be possible to set the camera so that the movable area can be captured.

The present invention was made in consideration of these circumstances, and its purpose is to provide a spatial magnetic field measurement system and a spatial magnetic field measurement method that are easy to prepare in advance and have few restrictions on what can be measured.

First Aspect of the Invention
A first aspect of the present invention is a spatial magnetic field measurement system including a magnetic probe device capable of scanning an arbitrary space and a terminal device that displays the spatial magnetic field of the arbitrary space, wherein the magnetic probe device includes a magnetic sensor unit consisting of one or more three-axis magnetic sensors, and a self-position estimation unit that includes a tracking camera and an inertial measurement unit that are integrally configured with the magnetic sensor unit and estimates the position and attitude of the magnetic sensor unit, and the terminal device includes a calculation unit that converts the measurement value of the three-axis magnetic sensor based on the estimated value of the self-position estimation unit and calculates a three-dimensional magnetic vector for each spatial coordinate scanned by the magnetic sensor unit, and a display unit that displays the three-dimensional magnetic vector of the arbitrary space. This is a spatial magnetic field measurement system.

According to the spatial magnetic field measurement system of the first aspect of the present invention, by scanning an arbitrary space with a magnetic probe device equipped with a magnetic sensor unit, a three-dimensional magnetic vector can be calculated for each spatial coordinate scanned by the magnetic probe device. In this case, the spatial magnetic field measurement system can estimate its own spatial position and attitude by a tracking camera and an inertial measurement unit integrally configured with the magnetic sensor unit, so that external equipment such as a camera for acquiring the spatial coordinates and its setting are not required. In addition, the spatial magnetic field measurement system can perform magnetic measurement even in a space where the measurement object cannot be photographed from the outside, for example, inside a steel pipe, in the gap between two adjacent devices, or near an object with a complex shape, as long as the magnetic probe device can be held up. Therefore, according to the present invention, a spatial magnetic field measurement system can be provided that is easy to prepare in advance and has few restrictions on the measurement object.

<Second aspect of the present invention>
A second aspect of the present invention is a spatial magnetic field measurement system in which, in the first aspect of the present invention described above, the terminal device subtracts a magnetic vector of the spatial magnetic field that is independent of the spatial coordinates from the three-dimensional magnetic vector as a geomagnetic vector.

According to the spatial magnetic field measurement system of the second aspect of the present invention, by extracting and canceling the geomagnetic component from the spatial magnetic field measured by the magnetic sensor unit, it becomes possible to measure the magnetic field with reduced influence of geomagnetic noise.

<Third aspect of the present invention>
A third aspect of the present invention is a spatial magnetic field measurement system in which, in the first aspect of the present invention described above, the terminal device displays the three-dimensional magnetic vector superimposed on object data of the measurement target that has been acquired in advance.

The spatial magnetic field measurement system according to the third aspect of the present invention makes it possible to clearly visualize the spatial correspondence between known object data, such as design drawings of the object to be measured, and the three-dimensional magnetic vectors measured and calculated in its surroundings.

<Fourth aspect of the present invention>
A fourth aspect of the present invention is a spatial magnetic field measurement system in which, in the first aspect of the present invention described above, the terminal device superimposes and displays the three-dimensional magnetic vector on an image of the object to be measured acquired by the tracking camera.

According to the spatial magnetic field measurement system of the fourth aspect of the present invention, even if there is no prior information on the measurement target, it is possible to visualize the spatial correspondence between the image of the tracking camera during magnetic measurement and the calculated three-dimensional magnetic vector based on the spatial coordinates estimated by the self-position estimation unit at the time when the image is captured.

Fifth aspect of the present invention
A fifth aspect of the present invention is a spatial magnetic field measurement system in which, in the first aspect of the present invention described above, the terminal device displays the three-dimensional magnetic vector superimposed on environmental data generated by the self-position estimation unit.

According to the spatial magnetic field measurement system of the fifth aspect of the present invention, by utilizing an algorithm that generates environmental data together with the self-position estimation of the magnetic probe device, it is possible to simultaneously measure the spatial magnetic field and scan the shape of the measurement target by scanning the magnetic probe device, and to accurately visualize the spatial correspondence with the calculated three-dimensional magnetic vector.

<Sixth aspect of the present invention>
A sixth aspect of the present invention is a spatial magnetic field measurement method including a magnetic measurement process of scanning an arbitrary space with a magnetic sensor unit consisting of one or more three-axis magnetic sensors, a self-position estimation process of estimating the position and attitude of the magnetic sensor unit using a tracking camera and an inertial measurement unit integrally configured with the magnetic sensor unit, a calculation process of converting the measurement values of the three-axis magnetic sensor based on the estimated values of the self-position estimation process and calculating a three-dimensional magnetic vector for each spatial coordinate scanned by the magnetic sensor unit, and a display process of displaying the three-dimensional magnetic vector in the arbitrary space.

According to the spatial magnetic field measuring method of the sixth aspect of the present invention, by scanning an arbitrary space with the magnetic sensor unit, a three-dimensional magnetic vector can be calculated for each scanned spatial coordinate. At this time, the tracking camera and inertial measurement unit configured integrally with the magnetic sensor unit can estimate the own spatial coordinates, so there is no need for external equipment such as a camera to obtain the spatial coordinates or for setting it up. Furthermore, even if the measurement target is, for example, the inside of a steel pipe, the gap between two adjacent devices, or near an object with a complex shape, and the magnetic sensor unit cannot be photographed from the outside, magnetic measurement is possible if the magnetic sensor unit can be held up. Therefore, according to the present invention, a spatial magnetic field measuring method can be provided that is easy to prepare in advance and has few restrictions on the measurement target.

<Seventh aspect of the present invention>
A seventh aspect of the present invention is a spatial magnetic field measurement method according to the sixth aspect of the present invention described above, wherein in the calculation step, a magnetic vector that is independent of the spatial coordinates among the spatial magnetic field of the arbitrary space is subtracted from the three-dimensional magnetic vector as a geomagnetic vector.

According to the spatial magnetic field measurement method of the seventh aspect of the present invention, by extracting and canceling the geomagnetic component from the spatial magnetic field measured by the magnetic sensor unit, it becomes possible to measure the magnetic field with reduced effects of geomagnetic noise.

<Eighth aspect of the present invention>
An eighth aspect of the present invention is a spatial magnetic field measurement method according to the sixth aspect of the present invention described above, wherein in the display process, the three-dimensional magnetic vector is superimposed on object data of the measurement target that has been acquired in advance and displayed.

The spatial magnetic field measurement method according to the eighth aspect of the present invention makes it possible to clearly visualize the spatial correspondence between known object data, such as design drawings of the object to be measured, and three-dimensional magnetic vectors measured and calculated in its vicinity.

Ninth aspect of the present invention
A ninth aspect of the present invention is a spatial magnetic field measurement method according to the sixth aspect of the present invention described above, wherein in the display process, the three-dimensional magnetic vector is superimposed on an image of the object to be measured acquired by the tracking camera and displayed.

According to the spatial magnetic field measurement method of the ninth aspect of the present invention, even if there is no prior information on the measurement target, it is possible to visualize the spatial correspondence between the image of the tracking camera during magnetic measurement and the calculated three-dimensional magnetic vector based on the spatial coordinates estimated by the self-location estimation process at the time when the image is captured.

<Tenth aspect of the present invention>
A tenth aspect of the present invention is a spatial magnetic field measuring method according to the sixth aspect of the present invention described above, wherein in the display process, the three-dimensional magnetic vector is superimposed on the environmental data generated in the self-position estimation process and displayed.

According to the spatial magnetic field measurement method of the tenth aspect of the present invention, by utilizing an algorithm that generates environmental data together with self-location estimation, it is possible to simultaneously measure the spatial magnetic field and scan the shape of the measurement target by scanning the magnetic sensor unit, and to accurately visualize the spatial correspondence with the calculated three-dimensional magnetic vector.

The present invention provides a spatial magnetic field measurement system and a spatial magnetic field measurement method that are easy to prepare in advance and have few restrictions on the object to be measured.

1 is an external configuration diagram of a spatial magnetic field measurement system according to the present invention. 2 is a block diagram showing the main internal configuration of a magnetic probe device and a terminal device. FIG. FIG. 11 is a sequence diagram showing an example of the operation of the spatial magnetic field measuring system. 13 is a display example of a three-dimensional magnetic vector viewed from a first direction. 13 is a display example of a three-dimensional magnetic vector viewed from a second direction. 13 is a display example of a three-dimensional magnetic vector viewed from a third direction.

The following describes in detail the embodiments of the present invention with reference to the drawings. Note that the present invention is not limited to the contents described below, and can be modified as desired without departing from the gist of the invention. Furthermore, the drawings used to explain the embodiments are all schematic representations of the components, and may include partial emphasis, enlargement, reduction, or omissions to facilitate understanding, and may not accurately represent the scale or shape of the components.

Figure 1 is an external configuration diagram of a spatial magnetic field measurement system 1 according to the present invention. The spatial magnetic field measurement system 1 includes a magnetic probe device 2 capable of scanning an arbitrary space, and a terminal device 3 that displays the spatial magnetic field in the arbitrary space. In the spatial magnetic field measurement system 1, the person measuring the magnetic field scans the magnetic probe device 2 in a three-dimensional space around a measurement target such as an electronic device, and the magnetic field distribution in the three-dimensional space is visualized on the terminal device 3.

The magnetic probe device 2 according to this embodiment has an external configuration including a gripping portion 10, a base portion 11, a magnetic sensor portion 12, and a spatial sensor portion 13. Note that the arrangement of the components of the magnetic probe device 2 is not limited to that shown in FIG. 1, and they can be arranged in various shapes and configurations as long as they have the same functions.

The gripping section 10 is formed in a shape that allows the operator to easily grip the magnetic probe device 2. The base 11 controls each of the functional modules of the magnetic probe device 2, which will be described later, and is provided with a power switch 11a and multiple operation buttons 11b. The magnetic sensor section 12 is a flat member in which multiple three-axis magnetic sensors (not shown in FIG. 1), which will be described later, are built in an array, and in this embodiment, constitute a 5 x 5 magnetic sensor array. The spatial sensor section 13, which will be described in detail later, has built-in sensors for estimating the self-position of the magnetic probe device 2.

In this embodiment, the terminal device 3 is a general-purpose PC, and performs calculations and visualization of the spatial magnetic field while communicating with the magnetic probe device 2 via an application for measuring the spatial magnetic field.

Next, the internal configuration of the magnetic probe device 2 and the terminal device 3 will be described in more detail. FIG. 2 is a block diagram showing the main internal configuration of the magnetic probe device 2 and the terminal device 3. The magnetic probe device 2 includes a self-position estimation unit 20, a three-axis magnetic sensor 21, an operation unit 22, a battery 23, a control unit 24, and a probe communication unit 25 as modules for each function.

The self-position estimation unit 20 is built into the spatial sensor unit 13 described above, and includes a tracking camera 20a and an inertial measurement unit 20b for obtaining estimates of the position and orientation of the magnetic probe device 2 in three-dimensional space.

In this embodiment, the tracking camera 20a includes two camera modules and acquires an image of the surroundings of the magnetic probe device 2 that is scanned in an arbitrary space. As a result, the self-position estimation unit 20 sequentially calculates the amount of movement of the magnetic probe device 2 in three-dimensional space from changes in the image. In this calculation, self-position estimation can be performed using a known algorithm such as SLAM (Simultaneous Localization and Mapping). Note that the SLAM algorithm can create surrounding environmental data at the same time as estimating the self-position.

The inertial measurement unit 20b is also called an IMU (Inertial Measurement Unit) and detects translational and rotational motion. In this embodiment, the inertial measurement unit 20b is a nine-axis IMU including a three-axis speed sensor, a three-axis acceleration sensor, and a three-axis geomagnetic sensor. The self-position estimation unit 20 can calculate the attitude of the magnetic probe device 2 in three-dimensional space (tilt angles in the three-axis directions) based on these measured values. The self-position estimation unit 20 may improve the accuracy of self-position estimation by also using measurement data from the inertial measurement unit 20b.

The three-axis magnetic sensor 21 is a sensor element that measures the spatial magnetic field in three axial directions, and one or more are built into the magnetic sensor unit 12. In this embodiment, the three-axis magnetic sensor 21 is configured as a 5 x 5 array, and each sensor independently measures the three-dimensional spatial magnetic field.

The operation unit 22 includes the above-mentioned power switch 11a for switching the power supply of the magnetic probe device 2 ON/OFF, and a number of operation buttons 11b for switching the start/end of magnetic measurement and selecting various modes. The operation unit 22 may also be provided with a display mechanism such as an LED for displaying the status of the magnetic probe device 2.

The battery 23 is a rechargeable power supply device built into the gripping unit 10, and in this embodiment, supplies power to each module of the magnetic probe device 2 via the control unit 24.

The control unit 24 is, for example, a known microcomputer control circuit, and manages the overall operation of the magnetic probe device 2. More specifically, the control unit 24 acquires data successively measured by the self-position estimation unit 20 and the three-axis magnetic sensor 21 in response to input operations from the operation unit 22 by the person measuring, and transmits the data to the terminal device 3 via the probe communication unit 25.

The probe communication unit 25 is a communication module for performing wireless two-way communication with the terminal device 3, and may employ communication means such as Wi-Fi (wireless LAN) or Bluetooth (registered trademark).

On the other hand, the terminal device 3 includes a calculation unit 30, a terminal communication unit 31, an input unit 32, a display unit 33, and a memory unit 34 as modules for each of the main functions.

The calculation unit 30 executes an application for spatial magnetic field measurement and calculates the spatial magnetic field by processing data from the magnetic probe device 2. The terminal communication unit 31 is a communication module that performs wireless communication with the probe communication unit 25 of the magnetic probe device 2. The input unit 32 is, for example, a keyboard or mouse, and is used by the person measuring to operate the application and set various parameters. The display unit 33 is, for example, a PC display, and displays the three-dimensional magnetic vector of an arbitrary space calculated by the calculation unit 30 via the application. The memory unit 34 stores the three-dimensional magnetic vector calculated by the calculation unit 30 as necessary.

Next, an example of the procedure for a spatial magnetic field measurement method using the spatial magnetic field measurement system 1 will be described. Figure 3 is a sequence diagram showing an example of the operation of the spatial magnetic field measurement system 1.

The magnetic probe device 2 is powered on when the power switch 11a is operated by the person performing the measurement (step S1). This starts up the control unit 24 in the magnetic probe device 2, and initialization processing of various sensors is performed (step S2).

In addition, when the person measuring the device starts the spatial magnetic field measurement application, the terminal device 3 performs an initialization process for the calculation and display described below (step S3).

When the initialization process is completed, the terminal device 3 calls the magnetic probe device 2 from the terminal communication unit 31 based on the input operation of the measurer via the input unit 32 (step S4). In response, the magnetic probe device 2 responds to the terminal device 3 from the probe communication unit 25 (step S5). This establishes communication between the magnetic probe device 2 and the terminal device 3. Note that the call to establish communication may be made from the magnetic probe device 2 to the terminal device 3.

The terminal device 3 also selects a display mode for spatial magnetic field measurement based on the input operation of the person measuring (step S6). Here, the display mode refers to a selection of drawing methods for the measurement target that are overlaid when the measured and calculated three-dimensional magnetic vector is displayed on the display unit 33, and in this embodiment, the display mode is selected from the object mode, captured image mode, and environmental data mode.

In object mode, three-dimensional magnetic vectors are superimposed on 3D CAD data of the measurement target that was created in advance, or 3D object data of the measurement target that was photographed in advance. In captured image mode, three-dimensional magnetic vectors are superimposed on an image of the measurement target acquired by the tracking camera 20a when scanning with the magnetic probe device 2. In environmental data mode, three-dimensional magnetic vectors are superimposed on environmental data generated by the self-position estimation unit 20 during the self-position estimation process.

Next, the person measuring the magnetic field presses the geomagnetic measurement button among the operation buttons 11b of the magnetic probe device 2, and rotates the magnetic probe device 2 in three-axis directions at a position away from the measurement target to measure the magnetic field (step S7). The magnetic probe device 2 transmits to the terminal device 3, together with its posture information in three-dimensional space during rotation and the measured magnetic data of the three-axis magnetic sensor 21 measured in synchronization with the posture information, as geomagnetic data (step S8).

The terminal device 3 calculates, for example, a magnetic vector that is independent of spatial coordinates among the spatial magnetic fields, as a geomagnetic vector (Gx, Gy, Gz) based on the geomagnetic data received from the magnetic probe device 2 (step S9). Note that the calculation of the geomagnetic vector (Gx, Gy, Gz) may use other known algorithms. Furthermore, if the influence of geomagnetism is not taken into consideration, the procedures from step S7 to step S9 may be omitted.

Then, the person measuring the magnetic field starts measuring the spatial magnetic field by pressing the measurement start button of the operation buttons 11b and scanning an arbitrary space around the measurement target with the magnetic probe device 2 (step S10). When the spatial magnetic field measurement starts, the magnetic probe device 2 sequentially transmits the spatial data of the three-axis magnetic sensor 21 acquired by the self-position estimation unit 20 and the magnetic data acquired by the three-axis magnetic sensor 21 to the terminal device 3 (step S11).

The spatial data here includes time-series three-dimensional position data {x(t), y(t), z(t)} estimated by the self-position estimation unit 20, and time-series attitude data {ψ(t), θ(t), φ(t)}. The magnetic data also includes time-series magnetic vector data {Bx(t), By(t), Bz(t)} acquired by each of the multiple three-axis magnetic sensors 21. These data are acquired at a high-speed sampling frequency.

When the terminal device 3 receives the spatial data and magnetic data from the magnetic probe device 2, it calculates the three-dimensional magnetic vector for each spatial coordinate scanned by the three-axis magnetic sensor 21 from the data and displays it on the display unit 33 (step S12).

More specifically, the calculation unit 30 can calculate the spatial coordinates of each of the multiple three-axis magnetic sensors based on the three-dimensional position data {x(t), y(t), z(t)} and attitude data {ψ(t), θ(t), φ(t)} sequentially acquired as the position and attitude of the inertial measurement unit 20b. Note that the relative positions of the inertial measurement unit 20b and each of the three-axis magnetic sensors are stored in advance.

The calculation unit 30 can also calculate a three-dimensional magnetic vector for each spatial coordinate, regardless of the posture of the magnetic probe device 2 at each timing, by vector converting (rotating) the magnetic vector data {Bx(t),By(t),Bz(t)} of each of the three-axis magnetic sensors 21 based on the posture data {ψ(t),θ(t),φ(t)} acquired sequentially. Here, when the geomagnetic vector (Gx, Gy, Gz) has been calculated as described above, it is possible to calculate a three-dimensional magnetic vector in which the influence of the geomagnetic field has been cancelled by subtracting this.

Then, the display unit 33 draws the three-dimensional magnetic vector calculated by the calculation unit 30 on the corresponding position coordinates of the image of the measurement target selected as the display mode. This allows the measurer to visualize the three-dimensional magnetic vector for each position coordinate in any space scanned by the magnetic probe device 2 in approximately real time.

The magnetic probe device 2 continues to measure and transmit spatial data and magnetic data while the operator is scanning the area around the measurement target (step S13, magnetic measurement process, self-position estimation process). The terminal device 3 also continues to calculate and draw a three-dimensional magnetic vector based on the spatial data and magnetic data successively received from the magnetic probe device 2 (step S14, calculation process, display process). As a result, the three-dimensional magnetic vectors successively calculated during the magnetic measurement are added to the image on the display unit 33. The display unit 33 may display the successively calculated three-dimensional magnetic vectors all at once after the magnetic measurement is completed.

The person measuring can end the magnetic measurement by pressing the measurement end button among the operation buttons 11b at any time (step S15). At this time, the terminal device 3 ends the calculation and additional display of the three-dimensional magnetic vector when notified of the end of the magnetic measurement from the magnetic probe device 2 (step S16) (step S17). In addition, the person measuring can perform an operation to store the measured three-dimensional magnetic vector in the memory unit 34 as necessary.

Then, if the magnetic probe device 2 is not to perform the next magnetic measurement, the power switch 11a is used to turn off the power (step S18). Also, the terminal device 3 is operated via the input unit 32 to end the spatial magnetic field measurement application (step S19).

The above sequence of steps for the spatial magnetic field measurement method is merely one example, and the specifications may be modified as appropriate to allow for changes in the order of operations or interrupt operations, etc., as long as the desired results are obtained.

Next, we will explain an example of displaying three-dimensional magnetic vectors obtained by the spatial magnetic field measurement system 1. Here, we show an example in which a U-shaped magnet P placed on a flat surface is the measurement target, and the space immediately above the U-shaped magnet P is scanned by the magnetic probe device 2.

Figure 4 is an example of a display of a three-dimensional magnetic vector viewed from a first direction. Figure 5 is an example of a display of a three-dimensional magnetic vector viewed from a second direction. Figure 6 is an example of a display of a three-dimensional magnetic vector viewed from a third direction. In other words, Figures 4 to 6 show the same vector distribution measured as a three-dimensional magnetic vector around the measurement target, but from different perspectives.

To show the correspondence between Figures 4 to 6, the U-shaped magnet P is shown placed on an XY plane with the X direction being the direction in which the end faces of the north and south poles at both ends face, and the Y direction being the direction in which the north and south poles move away from each other, with the thickness direction corresponding to the Z direction. Additionally, each three-dimensional magnetic vector is represented by a triangular pyramid, with the magnetic direction being represented by the shading of the pyramid. Here, the measured magnetic field is displayed in object mode, which superimposes the three-dimensional magnetic vector on the object data of the U-shaped magnet P created in advance.

As can be seen in each figure, the distribution of three-dimensional magnetic vectors was measured immediately above the U-shaped magnet P scanned by the magnetic probe device 2. In addition, particularly strong magnetic fields were measured near the north and south poles, and accurate magnetic vectors were calculated that correspond to the magnetic field lines emanating from the north pole and suctioning from the south pole. This confirms that even the handheld magnetic probe device 2 of the present invention can accurately measure the spatial magnetic field in any space.

As described above, according to the spatial magnetic field measurement system 1 of the present invention, by scanning an arbitrary space with the magnetic probe device 2 equipped with the three-axis magnetic sensor 21, it is possible to measure a three-dimensional magnetic vector for each spatial coordinate scanned by the magnetic probe device 2. At this time, the spatial magnetic field measurement system 1 can estimate its own spatial coordinates using the tracking camera 20a and the inertial measurement unit 20b configured integrally with the three-axis magnetic sensor 21, so that external equipment such as a camera for acquiring the spatial coordinates and its setting are not required. In addition, the spatial magnetic field measurement system 1 can perform magnetic measurement even in a space where the magnetic probe device 2 cannot be photographed from the outside, such as the inside of a long steel pipe, the gap between two adjacent devices, or the vicinity of an object with a complex shape, as long as the magnetic probe device 2 can be held up. Therefore, according to the present invention, it is possible to provide a spatial magnetic field measurement system 1 that is easy to prepare in advance and has few restrictions on the measurement object.

REFERENCE SIGNS LIST 1 Spatial magnetic field measurement system 2 Magnetic probe device 3 Terminal device 20 Self-position estimation unit 20a Tracking camera 20b Inertial measurement unit 21 Three-axis magnetic sensor 30 Calculation unit 33 Display unit

Claims (8)

A spatial magnetic field measurement system including a magnetic probe device capable of scanning an arbitrary space and a terminal device that displays a spatial magnetic field in the arbitrary space,
The magnetic probe device includes:
A magnetic sensor unit including one or more three-axis magnetic sensors;
a self-position estimation unit including a tracking camera and an inertial measurement unit integrally formed with the magnetic sensor unit, and estimating a position and an attitude of the magnetic sensor unit;
The terminal device
a calculation unit that converts the measurement values of the three-axis magnetic sensor based on the estimated value of the self-position estimation unit and calculates a three-dimensional magnetic vector for each spatial coordinate scanned by the magnetic sensor unit;
A display unit that displays the three-dimensional magnetic vector in the arbitrary space ,
A spatial magnetic field measuring system that subtracts a magnetic vector that is independent of the spatial coordinates from the three-dimensional magnetic vector as a geomagnetic vector . The spatial magnetic field measurement system according to claim 1, wherein the terminal device displays the three-dimensional magnetic vector superimposed on the object data of the measurement target that has been acquired in advance. The spatial magnetic field measurement system according to claim 1, wherein the terminal device displays the three-dimensional magnetic vector superimposed on an image of the measurement target acquired by the tracking camera. The spatial magnetic field measurement system according to claim 1, wherein the terminal device displays the three-dimensional magnetic vector superimposed on the environmental data generated by the self-location estimation unit. a magnetic measurement step of scanning an arbitrary space with a magnetic sensor unit including one or more three-axis magnetic sensors;
a self-position estimation step of estimating a position and an attitude of the magnetic sensor unit by a tracking camera and an inertial measurement unit integrally configured with the magnetic sensor unit;
a calculation step of converting the measurement values of the three-axis magnetic sensor based on the estimated value of the self-position estimation step, and calculating a three-dimensional magnetic vector for each spatial coordinate scanned by the magnetic sensor unit;
A display step of displaying the three-dimensional magnetic vector in the arbitrary space ,
A spatial magnetic field measuring method , wherein in the calculation step, a magnetic vector that is independent of the spatial coordinates among the spatial magnetic fields of the arbitrary space is subtracted from the three-dimensional magnetic vector as a geomagnetic vector . 6. The spatial magnetic field measuring method according to claim 5 , wherein in the displaying step, the three-dimensional magnetic vector is displayed superimposed on object data of the measurement target obtained in advance. 6. The spatial magnetic field measuring method according to claim 5 , wherein in the displaying step, the three-dimensional magnetic vector is displayed superimposed on an image of the object to be measured acquired by the tracking camera. 6. The spatial magnetic field measuring method according to claim 5 , wherein in said displaying step, said three-dimensional magnetic vector is displayed superimposed on the environmental data generated in said self-position estimating step.