JPH03122590A - Gravity displacement meter within shaking - Google Patents

Abstract

PURPOSE:To perform measurement even within the shaking of an airplane without receiving effect by mounting a pair of superconductive spheres floating by the magnetic field generated by a magnetic field generator and a position measuring device measuring the positions of the superconductive spheres. CONSTITUTION:A magnetic field generator 1 generates a magnetic field satisfying the condition of formula at the arbitrary point of a vacuum container. By the magnetic field, the magnetic force acting on superconductive spheres 2 is well-balanced with average gravity in a vertical direction and zero in a horizontal direction. A position measuring device 3 measures the superconductive spheres 2 to the coordinates axis fixed to a measuring system. Since the rotary motion (high in frequency) of the shaking of the measuring system is suppressed by springs 5 and rotary spheres 6, a displacement detector compares the measuring result of two superconductive spheres to make it possible to obtain the difference between the gravities at points A, B. Therefore, the displacement of gravity can be measured even in the shaking of an airplane without receiving the effect of the shaking.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a turbulent gravitational displacement meter that measures displacement of gravity due to the presence of a submarine, for example, while an aircraft is oscillating.

[Conventional technology]

Figure 2 shows a conventional gravimeter, and in the figure,
2 is a superconducting sphere, and 8 is a superconducting coil that generates a magnetic field to levitate the superconducting sphere 2.

The force of the magnetic field acting on the superconducting sphere 2 in Figure 2 is calculated as follows.

F, =-(R'/2) (t++hz+(hz"+2
h+bs)Z +・)F, =-(R'/2) ((h
l''/4-hlh3)y+... TsukasaF, =-(R'/2
) ((hz"/4-h+hx)x+"') However, R: Radius of the superconducting sphere Fξ: Force acting on the superconducting sphere in the ξ direction hl: Magnetic field at the point (0, O, O) hl: θh /θZ h3 :θ”h+/θZt Here, -R3/2h, ht= m gh2K +2h
lh3 > 0 hx”/4 hlh2>.

However, m: Superconducting sphere mass g: The superconducting sphere is stably levitated to the point (0, O, O) by adjusting the current flowing through the superconducting coil so as to satisfy the average gravitational acceleration at the measurement point. be able to.

If the gravity changes from mg to m (g + Δg) (Δg: gravitational acceleration displacement) in this state, the Z coordinate of the superconducting sphere will be Z = -m6g / (hz" + 2hthi),
Therefore, by measuring the Z coordinate of the superconducting sphere, Δ
You can know g.

[Problem to be solved by the invention]

Conventional gravimeters are configured as described above, but in order to stably levitate the superconducting sphere, the device must be used in a stationary state and cannot be used when it is in motion. .

This invention was made to solve the above-mentioned problems with the conventional devices, and its purpose is to obtain a device that can measure changes in gravity due to the presence of a submarine, etc. even when an aircraft is shaking. .

[Means to solve the problem]

The oscillating self-gravity displacement meter according to the present invention includes a magnetic field generator that generates a magnetic field, a pair of superconducting balls that levitate due to the magnetic field generated by the magnetic field generator, and a position that measures the position of the superconducting balls. A measuring device, a vacuum container that stores the superconducting sphere, a magnetic field generator 9 position measuring device, an outer box that fixes the vacuum container, a rotating ball that is attached to the outer box and rotates at high speed, and a spring that supports the outer box. and a displacement detector that detects the presence or absence of gravitational displacement by comparing changes in the positions of the pair of superconducting spheres.

[Effect]

Due to the Meissner effect, a superconducting sphere balances gravity in the vertical direction under a certain magnetic field configuration, but no force acts in the horizontal direction.

In this invention, the position of the superconducting sphere under these conditions is measured at two locations at the same time, and by comparing the two measurement results, the displacement of gravity between these two locations is determined. can detect the existence of Also, the centrifugal force of the rotating ball.

Due to the elasticity of the spring, the rotational motion component of the oscillation of the measurement system (
(The period is not sufficiently large compared to the time required for one measurement) can be suppressed.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing an oscillating self-gravity displacement meter according to an embodiment of the present invention, in which l is a magnetic field generator, 2
3 is a superconducting ball, 3 is a position measuring device, 4 is a vacuum container, 5 is a spring, 6 is a rotating ball, and 7 is an outer box.

The force acting on a superconducting sphere in a magnetic field is expressed as:

However, H is a magnetic field.

The magnetic field generator 1 generates a magnetic field that satisfies the following conditions at any point in the vacuum container.

However, g is the average gravitational acceleration in the measurement range.

As a result, the magnetic force acting on the superconducting sphere is balanced with the average gravity in the vertical direction, and is zero in the horizontal direction.

The position measuring device 3 measures the coordinates of the superconducting sphere 2 with respect to the coordinate axes fixed to the measurement system. Since the rotational movement (high frequency) of the measurement system is suppressed by the spring 5 and the rotating balls 6, the displacement detector compares the measurement results of the two superconducting balls to detect points A and B. You can get the difference in gravity at a point. The calculation method is as follows. In other words, the position of the superconducting sphere is changed by 3 times per sampling.
The method is to calculate the acceleration by measuring each time, and then calculate the difference in gravitational acceleration based on the difference.

θ t (xA - xm) Δgg = θ t, where Δgξ is (gravitational acceleration in the ξ direction acting on point A) - (gravitational acceleration in the ξ direction acting on point B), ξT is the superconducting sphere measured at one point is the ξ coordinate of

Due to the presence of the submarine, the gravity becomes (G・Δm)/r2 (G:
Universal gravitational constant, r: distance between the aircraft and the submarine.

Δm=difference in mass between the submarine and seawater).

Gravity on Earth changes depending on altitude, topography, etc., but by correcting these by accurately understanding the aircraft's position and accumulating gravity data in the measurement range, it is possible to detect changes in gravity due to the presence of submarines. can. As mentioned above, the influence of short-cycle swings can be suppressed by springs and rotating balls, but for long-cycle swings, the sampling period must be short enough to be considered short enough for this swing. This can be dealt with by

In addition, in the above explanation, we talked about the case where submarines are detected by being mounted on an aircraft, but a helicopter is used.

The same effect can be achieved even when installed on a ship.

Moreover, it is effective not only for detecting submarines, but also for searching for underground resources, predicting earthquakes, etc.

〔Effect of the invention〕

As described above, according to the oscillating gravity displacement meter according to the present invention, the measurement system uses a spring and a rotating ball to suppress the influence of high-frequency rotational motion, and a pair of superconducting balls levitated in a magnetic field. By measuring the change in position and comparing the measurement results, the displacement of gravity at two locations is detected, so it has the effect of being able to measure the displacement of gravity without being affected by the shaking of an aircraft, etc. .

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG. 2 is a configuration diagram showing a conventional gravimeter. In the figure, 1 is a magnetic field generator, 2 is a superconducting ball, 3 is a position measuring device, 4 is a vacuum container, 5 is a spring, 6 is a rotating ball, 7 is an outer box, and 8 is a superconducting coil. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] (1) A gravitational displacement meter used inside an object with vibration, which includes a magnetic field generator that generates a magnetic field, a pair of superconducting spheres that levitate due to the magnetic field generated by the magnetic field generator, and this superconducting sphere. a position measuring device that measures the position of each of the conducting spheres; a vacuum container that stores the superconducting sphere; an outer box that fixes the magnetic field generator, the position measuring device, and the vacuum container; and a high-speed device that is attached to the outer box. a rotating ball that rotates at a speed, a spring that supports the outer box, and a displacement detector that detects the presence or absence of gravitational displacement by comparing changes in the position of the superconducting ball. Gravity displacement meter.