CN102494679B - Superconducting magnetic levitation based north-seeking device - Google Patents

Abstract

A north-seeking device for superconducting maglev, comprising a turntable base (1), a horizontal turntable (2), a spirit level (3), a fixture (4), a cryogenic container (5), a refrigerator (6), and an azimuth reference line ( 7), heat transfer screen (8), rotor chamber (9), superconducting rotor (10), anti-radiation screen (11), equator signal reading pattern (12), levitation coil (13), drive coil (14) , polar axis sensor (15), equatorial sensor one (16) and equatorial sensor two (17). Detect the equatorial signal on the surface of the superconducting rotor (10) through the equatorial sensor to read the pattern (12), and obtain the angular velocity components ω ₁ and ω ₂ of the horizontal component of the earth's rotation angular velocity in the direction of the optical axis of the two equatorial sensors through calculation, through the formula α =arctan(ω ₁ /ω ₂ ) Calculate the value of the angle α between the azimuth reference line (7) and the true north direction.

Description

A north-finding device for superconducting magnetic levitation

technical field

The invention relates to a north-seeking device, in particular to a north-seeking device for superconducting magnetic levitation.

Background technique

The continuous development of new materials and low-temperature technology has accelerated the application of superconducting technology. The unique physical properties of superconductors have application advantages that other materials cannot match, such as unimpeded current carrying capacity, complete diamagnetism, and quantum coherence effects. High-precision superconducting instruments and equipment developed based on various characteristics of superconductors have important applications in energy, information, environmental detection, rail transit, medical diagnosis, and scientific instruments. The north finder is an instrument that measures the angle between its reference side and the geographic true north direction. It can provide information such as azimuth and attitude for other equipment. It has a wide range of applications in fields such as mining, geodetic surveying and resource surveying. The magnetometer north finder determines the north direction by measuring the geomagnetic field. Because it is easily affected by the external magnetic field generated by the surrounding electrical equipment, and the direction of the magnetic field at each position on the earth's surface is different, the accuracy of the magnetometer north finder is low. The astronomical north finder determines the orientation by measuring stars, which can achieve high accuracy, but it cannot be used underwater, in tunnels and in bad weather. The positioning accuracy of the pendulum compass north finder is higher, but the time for north finding is longer.

Contents of the invention

In order to overcome the shortcomings of the prior art and realize high-precision and fast orientation north-seeking, the present invention proposes a north-finding device based on superconducting magnetic levitation. The device of the invention has the characteristics of high north-seeking precision and short north-seeking time.

The north-seeking device of the present invention includes a turntable base, a horizontal turntable, a fixture, a level, an azimuth reference line, a cryogenic container, a refrigerator, a radiation shield, a heat transfer shield, a rotor cavity, a superconducting rotor, a suspension coil, a drive coil, and an equatorial sensor , Polar axis sensor.

The horizontal turntable is placed on the turntable base, and the cryogenic container is fixed on the fixture of the horizontal turntable. Use the spirit level on the horizontal turntable to adjust the level of the horizontal turntable and the cryogenic container, so that the rotation axis of the horizontal turntable and the rotation axis of the cryogenic container are kept perpendicular to the ground level, and the horizontal turntable rotates with the vertical line as the rotation axis.

The superconducting rotor is engraved with a signal reading pattern near the equator, and two equatorial sensors are fixed on the rotor cavity orthogonally, and the optical axes of the two equatorial sensors are perpendicular to each other on the equatorial level and point to the center of the superconducting rotor , the equatorial plane is parallel to the local water plane. The equatorial sensor measures the horizontal component of the earth's rotation angular velocity sensitive to the superconducting rotor and the rotational speed of the superconducting rotor by detecting the signal of the equator position and reading the pattern. The azimuth reference line is engraved on the horizontal turntable, the azimuth reference line is parallel to the optical axis of one of the equatorial sensors.

The signal reading pattern is composed of two identical right-angled triangles connected end to end engraved around the rotor equator, one long right-angled side of the right-angled triangle is parallel to the equator, the midline of the right-angled triangle coincides with the equator line, and the oblique The angle between the side and the equator is u, and the measurement range of the angular deflection of the superconducting rotor is proportional to the angle u.

The refrigerating machine is installed on the upper end of the low-temperature container, and the anti-radiation shield in the shape of a reel is fixed inside the low-temperature container through pull rods, and a heat transfer screen is arranged in the anti-radiation screen tube, and the heat transfer screen is fixed on the secondary cooling part of the refrigerating machine by screws. the lower end of the head. A rotor chamber is placed inside the heat transfer screen, and the outer wall of the rotor chamber is in close contact with the inner wall of the heat transfer screen. The heat transfer screen is used to directly conduct the cooling capacity of the secondary cold head of the refrigerator to cool the rotor cavity. The superconducting rotor is located in the rotor cavity, and suspension coils are arranged at the upper and lower ends of the rotor cavity, and the superconducting rotor is suspended by the suspension coils. The driving coil is arranged near the center of the inner hole of the superconducting rotor, the superconducting rotor is rotated by the driving coil, and the levitation position of the superconducting rotor is detected by the pole axis sensor installed on the top of the superconducting rotor.

位置的水平分量

在赤道传感器一和赤道传感器二的光轴方向上的分量，此分量分别为和

再通过计算得到赤道传感器一的光轴与真北方向的夹角α＝arctan(ω₁/ω₂)，即可得到水平转台上方位基准线与真北方向的夹角α值。The north-seeking method using the inventive device is to set the angle between the optical axis of the equator sensor one and the true north direction as α, and when the superconducting rotor rotates at a high speed, the relative deflection of the superconducting rotor and the rotor cavity changes, using The two equatorial sensors measure the horizontal component of the earth's rotation angular velocity in the direction of the optical axis of the two equatorial sensors, that is, the earth's rotation angular velocity ω _IE at the local geographic latitude is

horizontal component of position

The components in the optical axis direction of equatorial sensor 1 and equatorial sensor 2 are respectively and

Then by calculating the angle α=arctan(ω ₁ /ω ₂ ) between the optical axis of the equatorial sensor 1 and the true north direction, the value of the angle α between the azimuth reference line on the horizontal turntable and the true north direction can be obtained.

Description of drawings

Figure 1 Schematic diagram of the internal structure of the cryogenic container. In the figure: 5 cryogenic container, 6 refrigerator, 8 heat transfer screen, 9 rotor chamber, 10 superconducting rotor, 11 anti-radiation screen, 12 equatorial signal reading pattern, 13 levitation coil, 14 driving coil, 15 polar axis sensor, 16 equator sensor one, 17 equator sensor two;

Fig. 2 Schematic diagram of superconducting maglev north-seeking device. In the figure: 1 turntable base, 2 horizontal turntable, 3 spirit level, 4 fixture, 7 orientation reference line;

Figure 3. Schematic diagram of the expansion of the equatorial signal reading graph. In the figure: 18 rotor equator line, 19 superconducting rotor smooth surface;

Figure 4. Schematic diagram of the position of the equatorial sensor and the superconducting rotor.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 1, the internal structure of the cryogenic container includes a cryogenic container 5, a refrigerator 6, a heat transfer screen 8, a rotor cavity 9, a superconducting rotor 10, a radiation shield 11, an equatorial signal reading pattern 12, a suspension coil 13, a drive Coil 14, polar axis sensor 15, equatorial sensor one 16 and equatorial sensor two 17. The refrigerator 6 is installed on the upper end of the cryogenic container 5, and the anti-radiation screen 11 in the shape of a reel is fixed inside the cryogenic container 5 through pull rods, and the heat transfer screen 8 is arranged in the tube of the radiation protection screen 11, and the heat transfer screen 8 is fixed on the refrigerator by screws. 6 the lower end of the secondary cold head. A rotor chamber 9 is placed inside the heat transfer screen 8 , and the outer wall of the rotor chamber 9 is in close contact with the inner wall of the heat transfer screen 8 . The heat transfer screen 8 is used to directly conduct the cooling capacity of the secondary cold head of the refrigerator 6 to cool the rotor chamber 9, instead of the general cooling method of using liquid helium to soak the rotor chamber 9, which reduces the complexity of the device needing to input liquid helium, and reduces the The size and weight of the device. The superconducting rotor 10 is located in the rotor cavity 9, and the upper and lower ends of the rotor cavity 9 are provided with suspension coils 13, and the superconducting rotor 10 is suspended by the suspension coils 13. The driving coil 14 is arranged near the center of the inner hole of the superconducting rotor 10 , the superconducting rotor 10 is rotated by the driving coil 14 , and the levitation position of the superconducting rotor is detected by the polar axis sensor 15 installed on the top of the superconducting rotor 10 . The superconducting rotor 10 is engraved with an equatorial signal reading pattern 12 near the equator, and the equatorial signal reading pattern 12 is generally formed by mechanical cutting and laser ablation. Two equatorial sensors comprising equatorial sensor 1 16 and equatorial sensor 2 17 are fixed on the rotor cavity orthogonally, the optical axes of equatorial sensor 1 16 and equatorial sensor 2 17 are perpendicular to each other on the equatorial horizontal plane and point to the spherical center of superconducting rotor 10, The equatorial water plane is parallel to the local water plane.

As shown in FIG. 2 , the north-finding device of the present invention includes a turntable base 1 , a horizontal turntable 2 , a level 3 , a fixture 4 , a cryogenic container 5 , a refrigerator 6 and an azimuth reference line 7 . The horizontal turntable 2 is placed on the turntable base 1 , and the cryogenic container 5 is fixed on the fixture 4 of the horizontal turntable 2 . Utilize the spirit level 3 installed on the horizontal turntable 2 platform to adjust the level of the horizontal turntable 2 and the cryogenic container 5, so that the rotation axis of the horizontal turntable 2 and the rotation axis of the cryogenic container 5 are kept vertical to the ground level, and the horizontal turntable 2 is vertical to the ground. 360 degree rotation for the rotation axis. The low-speed rotation of the horizontal turntable 2 drives the cryogenic container 5 to rotate around the vertical line of the ground, which can eliminate the constant value drift related to the superconducting rotor 10 inside the cryogenic container 5 and the housing such as the rotor cavity 9, so that the measurement accuracy is higher.

位置的水平分量

在赤道传感器一16和赤道传感器二17的光轴方向上的分量，此分量分别为

和

即可通过公式α＝arctan(ω₁/ω₂)求解得到方位基准线7和真北方向N的夹角α的数值。As shown in Figure 3, the equatorial signal reading pattern 12 is expanded into a plane figure, the equatorial signal reading pattern 12 is composed of two identical right-angled triangles connected end to end in the vicinity of the rotor equator line 18 engraved on the superconducting rotor 10, the right-angled triangle A long right-angled side of the right-angled triangle is parallel to the rotor equator line 18, and the midline of the right-angled triangle coincides with the rotor equator line 18. The included angle between the hypotenuse of the right triangle and the rotor equator 18 is u, and the measurement range of the angular deflection of the superconducting rotor 10 is proportional to the angle u. The shorter the north-seeking time, the smaller the deflection angle of the superconducting rotor 10 relative to the rotor cavity 9, the smaller the range of the deflection angle of the superconducting rotor 10 relative to the rotor cavity 9, and the smaller the value of u. When the detection light of the equatorial sensor hits the equatorial signal reading pattern 12, the equatorial sensor outputs a high level, and when the detection light of the equatorial sensor hits the smooth surface 19 of the superconducting rotor, the output of the equatorial sensor is low. As shown in FIG. 4 , the azimuth reference line 7 is parallel to the optical axis of the equator sensor one 16 , and the included angle with the true north N direction is α. When the axes of rotation of the superconducting rotor 10 and the cryogenic container 5 were all parallel to the vertical line of the ground, the optical axes of the equatorial sensor one 16 and the equatorial sensor two 17 were all on the equatorial plane of the superconducting rotor 10, and the superconducting rotor 10 rotated now For one cycle, the first equatorial sensor 16 and the second equatorial sensor 17 respectively output two pulse signals with equal pulse width, and the pulse width can be converted into a certain angle rotated by the superconducting rotor 10 . By collecting the number of pulses per unit time, the rotational speed of the superconducting rotor 10 can be calculated. The suspended superconducting rotor 10 has no contact with the outside world, and its rotation axis is constant in space orientation, while the rotor cavity 9 is fixedly connected to the cryogenic container 5 and the rotating platform 2, and is affected by the rotation of the earth, so that the superconducting rotor 10 The rotating shaft is deflected relative to the rotor chamber 9. When the superconducting rotor 10 rotates once, the equator sensor 16 outputs two pulse signals with unequal pulse widths. ω ₁ can be calculated from the rotating speed of , and its direction is along the optical axis of the equatorial sensor 2 17 . Similarly, the second equatorial sensor 17 outputs two pulse signals with unequal pulse widths, and ω ₂ is obtained through calculation, and its direction is along the optical axis of the first equatorial sensor 16 . The angular velocity of the Earth's rotation at the local geographic latitude is

horizontal component of position

The component on the optical axis direction of equatorial sensor one 16 and equatorial sensor two 17, this component is respectively

and

That is, the value of the angle α between the azimuth reference line 7 and the true north direction N can be obtained by solving the formula α=arctan(ω ₁ /ω ₂ ).

Claims (1)

1. A north-seeking device for superconducting maglev, the north-seeking device includes a cryogenic container (5), a refrigerator (6), a radiation shield (11), a rotor cavity (9), and a superconducting rotor (10) , suspension coil (13), drive coil (14), refrigerator (6) is installed on the upper end of the cryogenic container (5), and the anti-radiation screen (11) in the shape of a reel is fixed inside the cryogenic container (5) by a pull rod, superconducting The rotor (10) is located in the rotor cavity (9), the suspension coils (13) are arranged at the upper and lower ends of the rotor cavity (9), and the drive coils (14) are arranged in the inner hole of the superconducting rotor (10), characterized in that: The device also includes a turntable base (1), a horizontal turntable (2), a spirit level (3), a fixture (4), an azimuth reference line (7), a heat transfer screen (8), an equatorial signal reading graphic (12), Polar axis sensor (15), equator sensor one (16) and equator sensor two (17); the horizontal turntable (2) is placed on the turntable base (1), and the cryogenic container (5) is fixed on the horizontal turntable (2 ) on the fixture (4); use the spirit level (3) installed on the table of the horizontal turntable (2) to adjust the level of the horizontal turntable (2) and the low-temperature container (5), so that the rotation axis of the horizontal turntable (2) and the cryogenic The rotation axis of the container (5) is kept perpendicular to the ground level, and the horizontal turntable (2) rotates with the vertical line as the rotation axis; a heat transfer screen (8) is arranged inside the radiation protection screen (11), and the heat transfer screen (8 ) is fixed to the lower end of the secondary cold head of the refrigerator (6) by screws; the rotor chamber (9) is placed inside the heat transfer screen (8), and the outer wall of the rotor chamber (9) is close to the inner wall of the heat transfer screen (8), The cold energy of the secondary cold head of the refrigerator (6) is directly conducted to cool the rotor cavity (9) through the heat transfer screen (8); the superconducting rotor (10) is engraved with a signal reading pattern (12) near the equator ), the equatorial sensor 1 (16) and the equatorial sensor 2 (17) are fixed on the rotor chamber (9) orthogonally, the optical axes of the equatorial sensor 1 (16) and the equatorial sensor 2 (17) are perpendicular to each other on the equatorial level and point to The center of the sphere of the superconducting rotor (10), the equatorial horizontal plane is parallel to the local horizontal plane; the azimuth reference line (7) is parallel to the optical axis of the equatorial sensor one (16) on the horizontal turntable (2); The north-seeking method using the north-seeking device is as follows: the superconducting rotor (10) is suspended and rotated at high speed through the suspension coil (13) and the driving coil (14), and the superconducting rotor (10) and the rotor cavity (9) are used Relative rotation position changes, measured by the equatorial sensor 1 (16) and equatorial sensor 2 (17) The angular velocity of the earth's rotation ω _IE at the local geographic latitude is horizontal component of position

The components in the direction of the optical axis of equatorial sensor two (17) and equatorial sensor one (16) are respectively

and

Then calculate the angle α=arctan(ω ₁ /ω ₂ ) between the optical axis of the equatorial sensor 1 (16) and the true north direction through computer calculation, and then the azimuth reference line (7) and the true north direction on the horizontal turntable (2) can be obtained. The value of the included angle α in the north direction. In the above formula, ω ₁ is measured by the equator sensor 1 (16), the direction of ω ₁ is along the optical axis direction of the equator sensor 2 (17), and ω ₂ is measured by the equator sensor 2 ( 17) It is measured that the direction of ω ₂ is along the optical axis of the equator sensor one (16).

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