JP2531194B2 - Squid magnetometer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a squid magnetometer used in the field of magnetic exploration, and more specifically to a squid magnetometer mounted on an aircraft, a ship, a vehicle, or the like.

2. Description of the Related Art As such a squid magnetometer, there is a use form in which it is mounted on an aircraft or the like and measures geomagnetism while sailing. In other words, the magnetic exploration is performed by measuring the magnitude of the geomagnetism with a squid magnetometer with high accuracy and detecting the minute change in the obtained geomagnetism.

FIG. 3 shows a simplified block diagram of a conventional squid magnetometer.

There, the liquid nitrogen 55 is inserted into the horizontal cryogenic device 50 in which the liquid nitrogen 55 is stored, and the squid sensor 10 that detects the magnitude of the earth's magnetism for each vector component, and each detected vector component is amplified as a signal. The basic configuration includes an amplifier 20 and a computing unit 40 that receives the amplified signal and combines the vector components to calculate the magnitude of the geomagnetism.

Problems to be Solved by the Invention However, when the geomagnetism is measured in a state where the traveling direction of the aircraft changes, there are the following disadvantages.

That is, since the squid sensor 10 that is in a fixed state with respect to the aircraft has a very high sensitivity and the range to be measured covers a wide range, even if the traveling direction of the aircraft changes gently, the terrestrial magnetism time The squid sensor 10 is normal for detection, but the amplifier 20 does not respond to the temporal change in the earth's magnetism, and as a result it is impossible to measure minute changes in the earth's magnetism. Is. In other words, in conducting the magnetic exploration, it is desirable to measure the geomagnetism while freely navigating the exploration area, but in the case of the above conventional example, the magnetic exploration is performed in a regulated state.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a squid magnetometer capable of measuring a minute change in geomagnetism even when the traveling direction of an airplane or the like changes. .

Means for Solving the Problems A squid magnetometer according to the present invention is provided with three X-axis, Y-axis, and Z-axis directions that are arbitrarily associated with each other and that are orthogonal to each other. , A squid sensor that detects the vector component of the geomagnetism in the Z-axis direction, and a computing unit that receives the detection result of the squid sensor and calculates the magnitude of the geomagnetism by combining the detected vector components. Based on each vector component of the remaining two detection directions so that the support mechanism that rotatably supports the sensor and the direction of the geomagnetism and one of the X-axis, Y-axis, and Z-axis directions always match. Servo mechanism for rotating the squid sensor.

Action According to such a squid magnetometer, the squid sensor is rotationally controlled so that the direction of X-axis, Y-axis, or Z-axis is always coincident with the direction of geomagnetism. The change over time can be substantially suppressed.

Example An example of a squid magnetometer according to the present invention will be described below with reference to the drawings. FIG. 1 is a simplified configuration diagram of a squid magnetometer, and FIG. 2 is a perspective view showing a squid sensor and a supporting mechanism together.

The squid magnetometer described in the present embodiment is a device that is mounted on an aircraft and measures the magnitude of the earth's magnetism while sailing, and the obtained data is a data processing computer (not shown). Continuously led to
This allows magnetic exploration.

Such a squid magnetometer is a squid sensor 10 that operates in a superconducting state, detects the magnitude of the earth's magnetism for each vector component, and the obtained detection result is input to an arithmetic unit via an amplifier 20.
The calculation unit 40 introduces the vector into the vector 40 and calculates the magnitude of the geomagnetism. Further, the servo mechanism 30 rotates the squid sensor 10 so that the direction of the detected geomagnetism and the Z-axis direction described later are always matched. The squid sensor 10
Is rotatably supported by the support mechanism 70, and then, the liquid nitrogen 55 is inserted into the cryogenic container 50 in which the liquid nitrogen is stored, and the geomagnetism is detected in this state. Hereinafter, details of the mechanical configuration of each unit will be described.

The cryogenic container 50 is a horizontal container having a cylindrical shape, in which liquid nitrogen 55 is stored. A magnetometer probe 60 for inserting and removing the squid sensor 10 and the like is fixed to the back surface of the flange 53 that closes the opening of the cryogenic container 50.
That is, the squid sensor 10 and the support mechanism 70 are provided inside the tip of the magnetometer probe 60. In the center of the outer surface of the flange 53, servo motors 32a, 32b (32b are not shown) that form a part of the servo mechanism 30.
Are attached respectively, and the flexible wires 321a and 321b respectively attached to the rotating shafts (not shown) are
It is adapted to be mechanically coupled to the support mechanism 70 through the magnetometer probe 60.

Hereinafter, the details of the support mechanism 70 will be described with reference to FIG.

The support mechanism 70 rotatably supports the disk mounting table 71 on which the squid sensor 10 is mounted, and the support shafts 711 and 711 provided on both outer sides of the disk mounting table 71 include a rotating frame 72.
Are rotatably supported on the inner surface of the magnet, and support shafts 722a and 722b provided on both outer sides of the rotary frame 72 are rotatably supported on the inner wall (not shown) of the magnetometer probe 60. Further, a ring 712 having a rack is fitted on the disk mounting table 71, and a ring having a rack is formed on the outside of the rotary frame 72.
A 721 is similarly fitted.

That is, the rotary frame 72 is adapted to rotate in the b direction in conjunction with the servo motor 32a by engaging the pinion 73 provided at the tip of the flexible wire 321a with the rack provided on the ring 721. The tip of the flexible wire 321a is rotatably supported on the inner wall (not shown) of the magnetometer probe 60.

On top of that, the disk mounting table 71 is connected to the flexible wire 321b.
By engaging a pinion 74 provided at the tip of the rack with a rack provided on the ring 712, the pinion 74 is rotated in the a direction in conjunction with the servomotor 32b. The support shaft
Flexible wire 321b led through the inside of 722a
The tip end of is rotatably supported in the through hole of the rotary frame 72.

Thus, if the servo motors 32a and 32b rotate, the rotation frame
72, Squid sensor according to the rotation of the disk mounting table 71
The direction of 10 will change.

In this way, the squid sensor 10 is biaxially controlled.
Is, for example, on each surface of the square bobbin 14 made of resin or the like,
The squids 11, 12, and 13 are each screwed in and provided.

Here, the detection direction of the squid 11 is the X axis, and the squid is
An orthogonal coordinate system is defined in which the detection direction of 12 is the Y axis and the detection direction of the squid 13 is the Z axis. In other words, this XYZ orthogonal coordinate system is based on the squid sensor 10 fixed to the rotary mounting table 71.
Is the standard. Each lead wire of the squid sensor 10 is guided to the outside via the rotary frame 72, the support shaft 722b, and the flange 53. However, all the members around the squid sensor 10 are made of a non-magnetic material.

Next, returning to FIG. 1 again, the electrical configuration of the squid magnetometer will be described in detail.

The X-axis component of the magnitude of the geomagnetism is output from the squid 11 as the detection signal 111, similarly, the Y-axis component is output from the squid 12 as the detection signal 121, and the Z-axis component is output from the squid 13 as the detection signal 131. Has been done. These signals are guided to the X-axis amplifier 21, the Y-axis amplifier 22, and the Z-axis amplifier 23, which form the amplifier 20, respectively. The amplifiers are all the same circuit.

That is, the signal 211 obtained by amplifying the detection signal 111 by the X-axis amplifier 21 is guided to the arithmetic unit 40 and the X-axis servo amplifier 31a described later, and similarly, the signal 221 obtained by amplifying the detection signal 121 by the Y-axis amplifier 22 is , The calculation unit 40 and a Y-axis servo amplifier 31b described later. Further, the detection signal 231 is sent to the Z-axis amplifier.
The signal 231 amplified in 23 is led only to the arithmetic unit 40.

Although not shown, the arithmetic unit 40 is an electronic circuit combining a square circuit, an adding circuit, a square root circuit, etc.,
The magnitude of the geomagnetism is calculated by vector-synthesizing the X-axis component, the Y-axis component, and the Z-axis component, which are respectively guided via the signals 211, 221, and 231. Then, the measured magnitude of geomagnetism is guided as a signal 41 to the data processing computer (not shown).

By the way, the servo mechanism 30 includes an X-axis servo amplifier 31a and a Y-axis servo amplifier 31b which guide signals 211 and 221, respectively, and servomotors 32a and 32b controlled based on control signals 311a and 311b output from the X-axis servo amplifier 31a and Y-axis servo amplifier 31b. It is configured to be equipped. That is, the servomotors 32a and 32b are controlled by using the signals 211 and 221 as feedback inputs, and as shown in FIG. 2, the rotary frames 7 are driven via the flexible wires 321a and 321b.
2. The disk mounting table 71 can be rotated respectively.

The operation of the squid magnetometer configured as described above will be described below.

When an aircraft equipped with such a squid magnetometer is sailing under a direction in which the direction of the geomagnetism and the Z-axis direction do not match, the X-axis component of the magnitude of the geomagnetism detected by the squid sensor 10 And the Y-axis component are finite values, so the servo motors 32a and 32b rotate by an amount corresponding to this value, whereby the squid sensor 10 is
It rotates in a direction such that the direction of the geomagnetism and the Z-axis direction coincide with each other. Moreover, this state is maintained even when the traveling direction of the airplane changes.

By placing the squid sensor 10 in such a state that the direction of the earth's magnetism and the Z-axis direction always coincide with each other, even when the traveling direction of the aircraft changes gently, the conventional example is used. Compared with the case, the temporal change of geomagnetism can be substantially suppressed. Therefore, the change over time in the detection signals 111, 121, 131 is caused by the X-axis amplifier 21,
It is possible to avoid that the slew rate of the Y-axis amplifier 22 and the Z-axis amplifier 23 is higher than the slew rate, that is, the normal signal amplification is performed, and the magnitude of the geomagnetism is controlled without being restricted in the traveling direction of the airplane. It is possible to detect minute changes.

However, the magnitude of the earth's magnetism theoretically has only the Z-axis component with a small temporal change, but since the X-axis and Y-axis components are not completely zero, the calculation unit 40 also considers this component. The magnitude of geomagnetism is calculated.

Note that the squid magnetometer according to the present invention is not limited to this embodiment, and a usage form in which magnetic exploration is performed while being mounted on, for example, a ship, a vehicle, or the like can be considered.

Further, depending on the type of the squid sensor 10, the cryogenic container 50 may not be required.

Further, the support mechanism 70 may of course have any configuration as long as it can rotatably support the squid sensor 10.

Effect of the Invention In the case of the squid magnetometer of the present invention, the X-axis,
Since the squid sensor is configured to rotate so that the detection direction of either the Y-axis or the Z-axis and the direction of the geomagnetism always match, even when the traveling direction of the aircraft or the like changes, It will be possible to substantially suppress the temporal change of the geomagnetism. Therefore, even in such a state, it is possible to measure a minute change in the geomagnetism.

[Brief description of drawings]

1 and 2 are diagrams for explaining an embodiment of a squid magnetometer according to the present invention. FIG. 1 shows a simplified configuration diagram of the squid magnetometer, and FIG. 2 shows a squid sensor and a support mechanism. A perspective view and FIG. 3 which are also shown are simplified configuration diagrams of a conventional squid magnetometer. 10 …… Squid sensor 20 …… Amplifier 30 …… Servo mechanism 40 …… Calculator 50 …… Cryogenic container 70 …… Support mechanism

Claims (1)

(57) [Claims] 1. A squid magnetometer for measuring the magnitude of the earth's magnetism, in which X-axis and Y-axis, which are orthogonal to each other, are arbitrarily associated with each other.
A squid sensor is provided which has three axes, the Z-axis direction as the detection direction, respectively, and detects the geomagnetic vector components in the X-axis, Y-axis, and Z-axis directions, respectively, and the detection result of the squid sensor is received. An arithmetic unit that calculates the magnitude of the geomagnetism by synthesizing the generated vector components, a support mechanism that rotatably supports the squid sensor, the direction of the geomagnetism, and the X-axis, Y-axis, and Z-axis directions. And a servo mechanism for rotating the squid sensor based on the respective vector components of the remaining two detection directions so that the detection direction always coincides with any one of the detection directions.