JPH0361878A - Magnetic field detector - Google Patents

Abstract

PURPOSE:To detect the magnetic field in a three-dimensional space highly accurately by providing a rotary shaft on a control stage, and arranging a sensor on the rotary shaft so that the axis of the sensor has a specified angle with respect to the shaft. CONSTITUTION:A rotary shaft 20 is supported at the central part of a hollow- disk-shaped control stage 13 so that the shaft can be rotated around the rotating axis of the shaft. A slant surface 20a is formed in the rotary shaft 20. A squid (magnetic-field detecting sensor) 22 and a coil 23 which are separated into the upper and lower sides with an insulating layer 21 are formed on the slant surface 20a by using a thin film technology. The angle formed by the axis of the rotary shaft 20 and the normal line of the slant surface 20a (i.e. the axis of the sensor) is set at a minute value delta. Therefore, when the direction of a magnetic field H agrees with the direction of the rotary axis of the rotary shaft 20, the magnetic field detected with the squid has the direction of Hcos delta. Therefore, when the detected value is divided by cos delta, the amount of change in magnetic field H can be detected.

Description

DETAILED DESCRIPTION OF THE INVENTION A0 Object of the Invention (1) Industrial Field of Application The present invention relates to a magnetic field detection device. The magnetic field detection device includes:
It is used to detect magnetic fields in fields such as searching for sunken ships and submarines, and exploring resources.

(2) Conventional technology Recently, devices for detecting magnetic fields with high precision include Squillad (
SQUID, Supercond-uct
ing Quantum Interface De
vice % superconducting quantum interference device) is used.

Squirad utilizes the phenomenon that the current flowing through the Gisefson element in the superconducting state depends on changes in the magnetic field with extremely high sensitivity.
About rsQUID, February issue, pp. 19-25
Published by the Institute of Electronics and Measurement Engineers) and Journal of the Institute of Electronics and Communication Engineers (198
2/6 VOL, J65-CN0.6, No. 475-482
``5QUID magnetometer using niobium thin film bridge and its performance evaluation'').

These publications describe magnetic flux detection devices using DCC Squirads and RF Squids.

The magnetic field can be detected by dividing the magnetic flux detected by the magnetic flux detection device described therein by the area of the detection coil.

Various methods have been known for detecting magnetic fields in three-dimensional space using magnetic field detection devices using such Squirad or other magnetic field detection sensors, such as the following methods (a) and (b). The following methods are known.

(a) Using a total of three sensors to detect the magnitude or amount of change in the magnetic field in the orthogonal x, y, and z axes directions, the magnitude or amount of change in each magnetic field in the three directions detected by the sensors How to synthesize.

(b) A total of three sensors are supported on the control table whose posture is controlled around the orthogonal X-axis and Y-axis to detect the magnitude or amount of change in the magnetic field in the orthogonal χ, Y, and Z-axis directions, respectively. The output of the sensor for detecting the magnetic field in the X and Y axis directions is 0.
By controlling the attitude of the control base in
Align the axial direction with the direction of the magnetic field. And 1. A method of detecting the magnitude of a magnetic field using a sensor for detecting magnetic fields in the z-axis direction.

In such a magnetic field detection device in three-dimensional space, if you want to detect the magnetic field with high precision, a Squillad is used as the sensor, and if detection accuracy is not an issue, you can use another sensor such as a fluxgate sensor instead of the Squillad. Sensors for detecting magnetic fields are often used.

(3) Problems to be Solved by the Invention By the way, the conventional magnetic field detection method described above requires a total of three sensors for magnetic field detection, one each in the X, Y, and Z directions. sensors had to be placed at right angles to each other. Another problem is that it is not easy to geometrically arrange the sensors at right angles to each other.

In view of the above-mentioned circumstances, the present invention is to enable highly accurate detection of the magnitude or amount of change in a magnetic field in a three-dimensional space without having to geometrically arrange a plurality of magnetic field detection sensors at right angles to each other. The task is to

B1 Structure of the Invention (1) Means for Solving the Problems In order to solve the above problems, the magnetic field detection device of the present invention includes:
comprising an attitude control device that controls the attitude of a control base on which a sensor for detecting a magnetic field is supported around an orthogonal X-axis and a Y-axis to hold the sensor in a predetermined attitude with respect to the direction of the magnetic field;
In a magnetic field detection device that detects the magnitude of the magnetic field from a detection signal of a sensor held in a predetermined attitude with respect to the direction of the magnetic field, a rotating shaft is provided on the control stand, and a rotating shaft 1 on the rotating shaft is provided on the control stand. The sensor is arranged so that the sensor axis has a predetermined angle δ with respect to the axis, and the attitude control device controls the attitude of the control base so that the alternating current component of the detection signal of the sensor becomes 0. It is characterized by being made to do.

(2) Effect Generally, when the magnetic field to be detected is detected, the angle between the axis (hereinafter referred to as the "sensor axis") that perpendicularly passes through the sensor that detects the magnetic field and the direction of the magnetic field π is θ. In this case, the magnetic field detected by the sensor increases cos θ.

By the way, in the magnetic field detection device of the present invention having the above-described configuration, the sensor axis is mounted on a rotating shaft that is rotatably driven on a control stand whose attitude is controlled around the X-axis and the Y-axis. Since the sensor is arranged so as to have an angle δ, if the axis of the rotating shaft is coincident with the direction of the magnetic field, the sensor will be able to match the direction of the magnetic field and the sensor regardless of the rotational position of the rotating shaft. Angle θ with the direction of the axis
is maintained at the predetermined angle δ. In this case, the angle θ between the sensor axis and the direction of the magnetic field is constant (ie, θ=δ) regardless of the rotational position of the rotating shaft. Therefore, the value of the magnetic field Hcosθ detected by the sensor is constant, and the detection signal does not include an alternating current component. however,
If the axis of the rotating shaft does not match the direction of the magnetic field, the angle θ between the sensor axis and the direction of the magnetic field changes as the rotating shaft rotates. The period of change of the angle θ is the same as the rotation period of the rotating shaft.

In this case, the value of the magnetic field Hcosθ detected by the sensor is
It changes in synchronization with the rotation period of the rotating shaft, and its detection signal includes an alternating current component.

However, the attitude control device controls the attitude of the table so that the AC component of the detection signal of the sensor becomes zero. Therefore, when the alternating current component is zero, the detection signal of the sensor is only the direct current component, and in this case, the sensor detects a predetermined angle (between the axis of the rotating shaft and the inclined angle with the surface normal) δ
The magnetic field component H cos δ shifted by the amount is detected.

(3) Example Next, an example of the magnetic field detection device of the present invention will be described.

In FIG. 1, a cylindrical cryogenic container 1 having an axis in the Y-axis direction includes a cylindrical sensor storage tank 1a and a refrigerant tank 1b disposed outside of the sensor storage tank 1a to cool the sensor storage tank 1a. and these sensor storage tank 1a and refrigerant tank 1b.
A heat insulating layer I placed around the outer periphery of the
It is equipped with C. A refrigerant 2 such as liquid helium or liquid nitrogen is stored in the refrigerant tank lb.

The opening of the sensor storage tank 1a is closed by a lid 3, and a connecting rod 4 extending inward from the inner surface of the lid 3 (to the left in FIG. 1) has an axis in the Y-axis direction at the tip. A cylindrical sensor storage case 5 is supported.

As shown in FIG. 2.3, a Y-direction rotation shaft 7.8 fixed to a substantially rectangular frame 6 is rotated by a pair of Y-direction end walls 5a and 5b of the cylindrical sensor storage case 5. Possibly supported. Note that the frame 6 is formed of a hollow prismatic member, and the Y-direction rotation shaft 7.8 is formed of a hollow cylindrical member, in which a rotational force transmission mechanism to be described later is disposed. It looks like this. Further, an outer ring 9 is fixed to the frame 6, and a rack 9a (see FIG. 3) that engages with a Y control pinion 10 is formed on one end surface of the outer ring 9. The Ye control binion 10 is rotatably supported by the side wall of the sensor storage case 5, and is connected to the Y control ultrasonic motor 12 supported by the lid 3 via a flexible cable 11. and,
The rotational force of the Y-control ultrasonic motor 12 is transmitted to the outer ring 9 and the frame 6 via the flexible cable 11, the Y-control binion 10, the rack 9a, etc., and controls the posture of the frame 6 around the Y-axis. It is configured as follows.

A hollow disk-shaped control stand 13 is formed by a pair of wall surfaces 6a and 6b facing apart from each other in the X-axis direction of the substantially rectangular frame 6.
Hollow X-direction rotating shafts 14, 15 fixed to are rotatably supported, respectively.

An inner ring 16 is fixed to the control base 13,
An X control pinion 17 is provided on one end surface of this inner ring 16.
(See FIG. 3) A rack 16a is formed which meshes with the rack 16a. The X control pinion 17 is rotatably supported by the side wall of the frame 6, and is connected to the flexible cable 1.
It is connected to an X-control ultrasonic motor 19 supported by the lid 3 through the front. Then, an ultrasonic motor 19 for use by XfltlJ, and the flexible cable 1
8, the Y control pinion 17, the rack 16a, and the like, the signal is transmitted to the inner ring 16 and the control stand 13, and is configured to control the attitude of the control stand 13 around the X axis.

A rotary shaft 20 is supported in the center of the hollow disc-shaped control base 13 so as to be rotatable around a shaft rotation axis perpendicular to the control base 13 . And this rotating shaft 20
, an inclined surface 20a is formed, and this inclined surface 2O
On a, an insulating layer 21 (see Fig. 6) is formed using thin film technology.
A squillard (that is, a sensor for detecting a magnetic field) 22 and a coil 23 are formed vertically separated. The angle formed between the axis of the rotating shaft 20 and the normal to the inclined surface 20a (i.e., the sensor axis) is a minute value δ.
is set to . Therefore, for example, when the direction of the magnetic field H to be detected coincides with the direction of the rotational axis of the rotating shaft 20, the magnetic field detected by the squillard 22 becomes H cos δ. Therefore, in that case, the amount of change in the magnetic field π can be detected by dividing the magnetic field detected by the SQUID 22 by cos δ.

As shown in FIG. 4.5, the rotary shaft 20 is provided with a helical gear 24 and a slip ring 25. As shown in FIG. 3, the helical gear 24 is operated via a transmission mechanism 26 disposed inside the hollow disc-shaped control base 13 and the frame 6 formed from a hollow prismatic column. , and is connected to a helical gear 27 rotatably supported on the inner surface of the frame 6. This helical gear 27 is connected via a hollow flexible cable 28 to a rotating shaft driving ultrasonic motor 29 (see FIGS. 1 and 3) supported by the lid 3. A through hole is formed in the center of the helical gear 27, and this through hole and the hollow flexible cable 28 are used to allow the flexible cable 18 to pass through. The rotational force of the rotary shaft driving ultrasonic motor 29 is transmitted to the rotary shaft 20 via the flexible cable 28, helical gear 27, transmission mechanism 26, helical gear 24, etc., and rotates the rotary shaft 20 around its axis. It is configured to rotate at a constant speed.

As shown in FIG. 5, the slip ring 25 is connected to a coil 23 (see FIG. 6) which is inductively coupled to the squillard 22 through a first connection line 30, and a brush that contacts the slip ring 25 31 is connected to one end of the second connection line 32.

As shown in FIG. 3, this second connection line 32 passes through a through hole formed in the frame 6 and the hollow Y-direction rotating shaft 8, and is connected to a connection terminal 33 provided on the lid 3. ing.

Referring again to FIG. 1, the connection terminal 33 is connected to a sensor exciter 41 and a magnetic field detection circuit . The relationship among the sensor exciter 41, the magnetic field detection circuit 42, the SQUID 22, the coil 23, etc., and the details of the magnetic field detection circuit 42 are shown in FIG.

In FIG. 6, the SQUID 22 has a direction in which an external magnetic field vertically passes through the SQUID 22 (sensor axial direction).
It is used as a detection coil for detecting a change in the component H cos θ (where θ is the angle between the direction of the external magnetic field H and the direction of the axis passing through the SQUID 22). A coil 23 arranged so as to be inductively coupled to this squirrel 22 forms a resonant circuit together with a capacitor.

This resonant circuit receives weak high frequency power from a sensor exciter 41 that outputs a high frequency (for example, 22 MHz) via the connection terminal 33, and resonates at 22 Mk.

The 22 MHz signal of the resonant circuit is connected to the external magnetic field H SQUID 2.
The amplitude is modulated according to the amount of change in the magnetic field component H cos θ passing through 2. This amplitude-modulated signal, that is, the magnetic field detection signal is transmitted to the RF amplifier and detector 43 of the magnetic field detection circuit 42.
The signal is amplified and detected and input to the lock-in amplifier 44.

The lock-in amplifier 44 is a buffer amplifier 45.
, a phase detector 46, a reference signal oscillator 47, and the like. The reference signal oscillator 47 generates a reference signal (for example, 50 KHz) for improving detection accuracy, and this reference signal is applied to the coil 23. And the lock-in amplifier 44
Among the input signals from the amplifier and detector 43, 50KH
Only the signal modulated by z is detected and output to the integrating amplifier 48. The signal output from the integrating amplifier 48 passes through a feedback line 49 and causes the coil 23 to generate a feedback magnetic field.

This feedback magnetic field is a component Hco of the external magnetic field H.
It has a size and direction that cancels out the amount of change in sθ. Therefore, the output signal of the integrating amplifier 48 corresponds to the change in the component H cos θ of the external magnetic field H. Furthermore, when the direction of the axis of the rotary shaft 20 matches the direction of the external magnetic field H, the output signal of the integrating amplifier 48 is only a DC signal, but when the direction does not match, the output signal includes an AC signal. Become. The output signal of this integrating amplifier 48 is input to a DC/AC separator 50.

The DC/AC separator 50 separates the output signal of the integrating amplifier 48 into a DC component and an AC component, outputs only the DC component therein to the correction calculator 51, and outputs the AC component to the amplitude/phase detector. 52.

An amplitude and phase detector 52 transmits amplitude and phase information obtained from the AC component to a motor drive signal generator 53 for X and Y control.
At the same time, the amplitude information is output to the correction calculator 5.
It is also output to 1.

On the other hand, the rotary shaft driving ultrasonic motor 29 is configured to be driven by a rotary shaft motor driver 54. The rotational position of the rotary shaft driving ultrasonic motor 29, that is, the rotational position of the rotary shaft 20, is detected by a rotation angle detector 55, and the detection signal is input to the X, Y control motor drive signal generator 53. has been done.

The X, Y control motor drive signal generator 53 generates the amplitude and
Based on the input signals from the phase detector 52 and the rotation angle detector 55, an X control motor control signal and a Y control motor control signal are output to the X and Y control motor driving tools 56.

The X, Y control motor driver 56 outputs an X control motor drive signal to the X control motor 19 according to the input signal, and also outputs a Y control motor drive signal to the Yllf.
Output to the il motor 12.

The attitude control device of this embodiment (the attitude control device that holds the sensor in a predetermined attitude with respect to the direction of the magnetic field) is composed of the components indicated by the numerals 6 to 20 and 52 to 56. Further, the magnetic field detection device of this embodiment is constituted by the components indicated by the above-mentioned numerals 1 to 56.

Next, the operation of the embodiment having the above-described configuration will be explained.

In FIG. 7, x, y, and z are orthogonal coordinate axes fixed to the control base 13J:, and the X axis is the X-direction rotation axis 14.
15 (see FIG. 3), and the Z axis coincides with the axial direction of the rotating shaft 20. and,
The y-axis is perpendicular to the X-axis and Z-axis.

In FIG. 7, the unit vector of the magnetic field detected by the SQUID 22 (hereinafter referred to as the "unit vector J in the sensor direction") is g, and the direction of the axis (sensor axis) that perpendicularly passes through the SQUID 22 and the direction of the magnetic field H. The magnitude of the magnetic field acting on the Squillad 22 is H
It is expressed as 3cosθ. This value is equal to the inner product of the magnetic field vector H and the unit vector g in the sensor axis direction. The inner product of each vector and g is calculated by dividing each vector into the x, y, and z axis components as follows.

Let δ be the angle between the axis (sensor axis) that perpendicularly passes through the SQUID 22 and the Z-axis, and φ be the angle that the projection of the unit vector S in the sensor direction onto the x-y plane makes with the X-axis.
shall be. In this case, when the rotating shaft 20 rotates, δ is constant, but φ changes periodically between O and 2π. x, y of the unit vector g in the sensor direction in this case
, the components in the z-axis direction are expressed as Sx, Sy, and Sz as follows.

5x=Ssinδcosφ S3'=Ssinδsinφ 5Z=Scosδ Here, if the unit vector in the sensor direction is set to S=1, the above-mentioned Sx, Sy, and Sz become as follows.

5x = sin δ cos φ 5 V = sin δ sin φ S z = cos δ In addition, in FIG. When ψ is expressed as Hx, Hy, and Hz, the components of the magnetic field in the x', y, and z axis directions are as follows.

Hx=Hsinζcosψ Hy=H5in(sinψ Hz=Hcosζ Therefore, the inner product of the front magnetic field and the unit vector g in the sensor axis direction is expressed by the following equation.

H・3=Hx-3x+Hy-3y 10Hz-3z=Hsi
nζcosψsinδCoSφ+Hsinζsinψs
inδsinφ+Hcosζcosδ −・−−−−
(1) Therefore, if the sensor for detecting the magnetic field is a sensor that can detect the magnitude itself before the magnetic field, such as a flux gate sensor, the sensor output will be the above (
It is given by equation 1), and since the SQUID 22 is used as the sensor in this embodiment, the detection signal of the SQUID 22 corresponds to the change before the magnetic field.

That is, the magnetic field detection circuit 42 shown in FIG.
detects the amount of change in the magnetic field from the magnetic field corresponding to the magnetic flux passing through the SQUID 22 at the start of detection. Therefore, let δ (= constant) and when time L = t o, H =
Ho, ζ=ζ. , ψ=φ. , φ=φ. (=ωto), when time 1=1) (=H1ζ=ζ, ψ=ψ, φ
= ωt (ω is the angular frequency of the rotating shaft 20), then
The output signal A of the magnetic field detection circuit 42 is as follows.

A = (Iku・”g) v-t (Iku・3) t-t.

= (l(stnζcosψsinδcosωt+H5
in(sinψsinδsinωt+f(cosζ c
osδ) −(16sinζacosψ6sinδcosωt.

+Ho5tnζosinψ6sinδ sinωt.

+ Hocos (, cos δ) = sin δ (H sin ζ cos ψ cos ω 10H5in (sin ψ 5ina + Ha Sin ζ cos ψ, cos ωL.

Ho5inζostnψ6 sin ωto )+
cosδ (Hcosζ−HocO5ζO)−sin
δ (Hsinζ cos(ωt−ψ)−Hosinζ
6 cos (ω1.-ψo)) 10 cos δ (H cos ζ
−H0CO5ζ0)=Hsinδ 5in(cos (
(+1 t-ψ)+Hcosδ cosζ Ho5in δsin ζ6CO3(ωL o
−ψo)) Hocos δcos Co) −
−−−−−−−=−−−−−−−−−−−−−−−−−
--(2) In the above equation (2), ζ(l, ζ. (In the case of l, sinζ=ζ, cosζ=l−ζ2/2,
sinζO豐ζ. , cosζ. =1-ζ. Approximating to '/2, the output signal A of the magnetic field detection circuit 42 expressed by the above equation (2) is expressed by the following equation.

A −Hζsinδcos(ωt−ψ)+Hcosδ(
1-ζ wealth/2) tLo ζakin 6 Cog (0) Lo-ψ
o)]-H@Co3δ(1-ζ,”/2)) −
-------=- (3) In the above equation (3), the first term is the AC component A1, which is output from the magnetic field detection circuit 42 to the amplitude/phase detector 52. In addition, in the above formula (3), the second
．． Term 3.4 is a DC component and is output from the magnetic field detection circuit 42 to the correction calculator 51. The second term is a DC component At that changes as the magnetic field H changes.

Further, the third term and the fourth term are DC components that are initialized at time 1-1°, and the value of this term 3.4 is removed by the correction calculator 51 in Figs. It has become so.

Output signal A of the magnetic field detection circuit 42 expressed by the above formula (3)
Among them, the AC component Al is expressed by the following formula.

A, = H (sin δ cos (ω one ψ) −1
(4) From equation (4), the amplitude value B of the AC component A1 of the detection signal of the magnetic field detection circuit 42 can be expressed by the following equation.

B=2Hζsinδ ---(5
) From equation (5), it can be seen that the amplitude B of the AC component A1 of the output signal of the magnetic field detection circuit 42 is proportional to the angle ζ formed between the direction of the magnetic field and the axis of the rotating shaft 20. Therefore, the AC component A1 can be used as an attitude control signal for the control base 13.

Furthermore, considering the DC component A2 that changes with the change in the magnetic field H among the DC components of the detection signal A of the magnetic field detection circuit 42 expressed by the equation (3), Al = T (cos
δ(1-ζz/2)=Hcosδ-(Hζtcosδ)
/2) −・−・・−−−1・−1−−・−1−−−・
-.-(6) In equation (6), the second term is smaller than the first term, so if it can be ignored, equation (6) can be expressed as the following equation.

Ax = Hcos δ −・・・−・ ・−・・−
- Song... - Song... (7) Therefore, since the DC component At of the output signal A of the magnetic field detection circuit 42 is proportional to the magnitude or amount of change in the magnetic field π, the DC component Az increases the magnetic field H. It is possible to detect the change in .

Furthermore, in the above formula (6), ζ, ζ. When the value of is large and the second term cannot be ignored, the amplitude B of the AC signal A shown in equation (5) also becomes large, so the amplitude B
It is also possible to correct the DC component of the detection signal of the magnetic field detection circuit 42 (that is, cancel the second term of the equation (6)) using the value of .

For example, the value of the following equation is used as the correction value C.

C=(B”cosδ)/8Hosin”δ= (4H
” (”sin”δcos δ) / 8H
−sin”δ−−−−・−−−−・・−−−−・−・(
8) By approximating this equation (8) with HLiH, the following equation (9) is obtained.

C-(H"ζ"cosδ') / 2 -------
−−−−−−−−−−−−−−−−−(9) This equation is equal to the above equation (6). Therefore, the amplitude B of the output signal of the amplitude/phase detector 52 is Correction calculator 5
1, and in the correction calculator 51, the above (8)
After the equation is calculated, it is added to the DC component of the output signal of the magnetic field detection circuit 42. As a result, the above formula (
The second term of 6) can be canceled.

The output signal of the amplitude/phase detector 52 is inputted to the X, Y control motor control signal generator 53 together with the output signal of the rotation angle detector 55.

A motor control signal generator 53 for X and Y control generates a motor control signal for Xa and Hs
A motor control signal Ya for Y control proportional to inζ cos ψ (see Fig. 7) is formed, and these signals are expressed as
It is output to the regular motor driver 56.

The X, YI control motor driver 56 receives input signals Xa,
Amplify Ya to X! Motor drive signal for control control X and Y
It outputs the @regular motor drive signal Yb, outputs the X control motor drive signal xb to the XNIm motor 19, and outputs the Y control motor drive signal Yb to the Y control motor 12.

At this time, the X and YIII motors 19 and 12 control the attitude of the control base 13 so that the signals Xa and Ya become O.

According to the above-described embodiment of the present invention, the SQUID itself is used as the detection coil, and the conventional detection coil and the magnetic field transmission section provided between the detection coil and the conventional SQUID are omitted, resulting in a simple configuration. become. Furthermore, since the sensor axis of the SQUID 22 is always aligned with the direction of the magnetic field, changes in the magnetic field can be detected with high precision.

Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various modifications can be made.

For example, it is possible to use various sensors other than the SQUID 22 as a sensor for detecting a magnetic field. In that case, it becomes possible to detect not only the change in the magnetic field but also the magnitude of the magnetic field itself. Furthermore, instead of the ultrasonic motor, various motors such as an air-core motor that does not use permanent magnets can be used as the X and Y control motors and the rotary shaft drive motors.

C0 Effects of the Invention As described above, according to the magnetic field detection device of the present invention, a rotating shaft is provided on the control table, and the sensor axis is placed on the rotating shaft at a predetermined angle (for example, δ) with respect to the axis. The sensor is arranged so that the sensor has a magnetic field, and the attitude control device controls the attitude of the table so that the alternating current component of the detection signal of the sensor becomes O. The magnetic field component in the direction shifted by the angle of is always detected. Therefore, a magnetic field in a three-dimensional space can be detected with high precision even if a plurality of magnetic field detection sensors are not geometrically arranged at right angles to each other.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the overall configuration of an embodiment of the magnetic field detection device of the present invention, and FIG. 2 is an explanatory diagram of a control stand used in the embodiment.
FIG. 3 is an explanatory diagram of the driving force transmission unit to the control stand of the same embodiment,
Fig. 4 is a longitudinal cross-sectional view of the same control board, Fig. 5 is an enlarged cross-sectional view of the main part of Fig. 4, Fig. 6 is a detailed explanatory diagram of the signal detection part of the same embodiment, and Fig. 7 is a diagram of the same embodiment. FIG. 4 is a diagram showing a magnetic field vector and a sensor vector in an action explanatory diagram. 13... Control stand, 20... Rotating shaft, 22...
・Squirad patent applicant Shimadzu Corporation

Claims (1)

[Scope of Claims] An attitude control device that controls the attitude of a control base on which a sensor for detecting a magnetic field is supported around an orthogonal X-axis and a Y-axis to maintain the sensor in a predetermined attitude with respect to the direction of the magnetic field. Equipped with
In a magnetic field detection device that detects the magnitude of the magnetic field from a detection signal of a sensor held in a predetermined attitude with respect to the direction of the magnetic field, a rotating shaft is provided on the control base, and a rotating shaft is mounted on the rotating shaft. The sensor is arranged so that the sensor axis has a predetermined angle (δ) with respect to the axis, and the attitude control device controls the attitude of the control base so that the AC component of the detection signal of the sensor becomes 0. A magnetic field detection device characterized in that it is controlled.