Background noise determination method and manufacturing method of low-noise MHD angular velocity sensor

Abstract

The invention provides a background noise determination method and a manufacturing method of a low-noise MHD angular velocity sensor. The background noise determination method comprises the steps that on the basis of appearance data of an upper electrode, a lower electrode, a conductive fluid ring, a magnetic core, a primary winding and a secondary winding in the MHD angular velocity sensor, parameter values of a plurality of equivalent devices included in an equivalent circuit model of the MHD angular velocity sensor are determined, and the appearance data comprise size data, material data and shape data; determining the noise voltage power spectral density of the MHD angular velocity sensor based on the respective parameter values of the plurality of equivalent devices and the turn ratio of the primary winding to the secondary winding; and determining the background noise of the MHD angular velocity sensor based on the noise voltage power spectral density of the MHD angular velocity sensor.

Description

Technical Field

[0001] The present invention relates to the technical field of background noise determination, and in particular to a background noise determination method and a manufacturing method of a low-noise MHD angular velocity sensor. Background Art

[0002] With the continuous advancement of space science and technology, particularly in areas such as high-resolution Earth observation, deep space exploration, and laser communications, the requirements for spacecraft payloads to maintain stable attitude and precise pointing during missions are becoming increasingly stringent. However, payload platforms are extremely sensitive to the effects of micro-angular vibration disturbances and are easily affected by micro-angular vibrations of space structures. This micro-angular vibration of space structures limits further improvements in the accuracy of high-precision spacecraft payload attitude and pointing control.

[0003] Magnetohydrodynamics (MHD) angular velocity sensor is a high-frequency angular motion sensor with the characteristics of low noise, wide bandwidth, miniaturization, long life, etc. It is insensitive to acceleration shock and is currently a very direct, effective and reliable sensor used for wide-band micro-angular vibration measurement of spacecraft payload platforms.

[0004] The noise floor is a key parameter for measuring the ultimate resolution of an MHD angular rate sensor. It is determined by the sensor's internal sensor element and detection circuitry. However, calculating the noise floor involves complex electrical coupling between the sensor element and the detection circuitry. Typically, achieving the desired noise floor design target can only be achieved through empirical experimentation, increasing sensor design complexity, R&D cycle time, and manufacturing costs. Summary of the Invention

[0005] In view of this, the present invention provides a method for determining the noise floor of a low-noise MHD angular velocity sensor, comprising: determining parameter values ​​of multiple equivalent components included in an equivalent circuit model of the MHD angular velocity sensor based on respective shape data of an upper electrode, a lower electrode, a conductive fluid ring, a magnetic core, a primary winding, and a secondary winding in the MHD angular velocity sensor, wherein the shape data includes dimensional data, material data, and shape data; determining a noise voltage power spectral density of the MHD angular velocity sensor based on the respective parameter values ​​of the multiple equivalent components and a turns ratio between the primary winding and the secondary winding; and determining the noise floor of the MHD angular velocity sensor based on the noise voltage power spectral density of the MHD angular velocity sensor.

[0006] Optionally, the above-mentioned multiple equivalent devices include a conductive equivalent resistance, an upper equivalent resistance, a lower equivalent resistance, an upper contact equivalent resistance, a lower contact equivalent resistance, the equivalent resistance of the above-mentioned primary winding, the equivalent inductance of the above-mentioned primary winding and the equivalent resistance of the above-mentioned secondary winding, wherein the above-mentioned conductive equivalent resistance represents the equivalent resistance of the above-mentioned conductive fluid ring, the above-mentioned upper equivalent resistance represents the equivalent resistance of the above-mentioned upper electrode in the current path of the above-mentioned MHD angular velocity sensor, the above-mentioned lower equivalent resistance represents the equivalent resistance of the above-mentioned lower electrode in the above-mentioned current path, the above-mentioned upper contact equivalent resistance represents the equivalent resistance of the contact surface between the above-mentioned conductive fluid ring and the above-mentioned upper electrode, and the above-mentioned lower contact equivalent resistance represents the equivalent resistance of the contact surface between the above-mentioned conductive fluid ring and the above-mentioned lower electrode.

[0007] Optionally, the above-mentioned parameter values ​​of multiple equivalent devices included in the equivalent circuit model of the MHD angular velocity sensor are determined based on the respective appearance data of the upper electrode, lower electrode, conductive fluid ring, magnetic core, primary winding and secondary winding in the MHD angular velocity sensor, including: determining the parameter value of the conductive equivalent resistance based on the appearance data of the conductive fluid ring; determining the parameter value of the upper equivalent resistance based on the appearance data of the upper electrode; determining the parameter value of the lower equivalent resistance based on the appearance data of the lower electrode; determining the parameter value of the upper contact equivalent resistance based on the respective appearance data of the upper electrode and the conductive fluid ring; determining the parameter value of the lower contact equivalent resistance based on the respective appearance data of the lower electrode and the conductive fluid ring; determining the parameter value of the equivalent resistance of the primary winding based on the appearance data of the primary winding; determining the parameter value of the equivalent resistance of the secondary winding based on the appearance data of the secondary winding; and determining the parameter value of the equivalent inductance of the primary winding based on the appearance data of the magnetic core and the number of turns of the primary winding.

[0008] Optionally, the equivalent circuit model includes a sensing element, a transformer, and an amplifier; and determining the noise voltage power spectral density of the MHD angular velocity sensor based on parameter values ​​of each of the multiple equivalent components and the turns ratio of the primary winding to the secondary winding includes: determining the noise voltage power spectral density of the equivalent resistance of the sensing element, the noise voltage power spectral density of the equivalent resistance of the primary winding, and the noise voltage power spectral density of the equivalent resistance of the secondary winding based on the parameter values ​​of the multiple equivalent components; determining a low-frequency cutoff frequency after the transformer and the amplifier are connected based on the equivalent resistance of the sensing element, the equivalent resistance of the primary winding, and the equivalent inductance of the primary winding; and determining the noise voltage power spectral density of the MHD angular velocity sensor based on the gain of the amplifier, the noise voltage power spectral density of the amplifier, the low-frequency cutoff frequency after the transformer and the amplifier are connected, the turns ratio, the noise voltage power spectral density of the equivalent resistance of the sensing element, the noise voltage power spectral density of the equivalent resistance of the primary winding, and the noise voltage power spectral density of the equivalent resistance of the secondary winding.

[0009] Optionally, the above-mentioned determination of the noise voltage power spectrum density of the equivalent resistance of the above-mentioned sensor element, the noise voltage power spectrum density of the equivalent resistance of the above-mentioned primary winding, and the noise voltage power spectrum density of the equivalent resistance of the above-mentioned secondary winding based on the parameter values ​​of each of the above-mentioned multiple equivalent devices includes: obtaining the equivalent resistance of the sensor element in the equivalent circuit model of the above-mentioned MHD angular velocity sensor based on the above-mentioned conductive equivalent resistance, the above-mentioned upper equivalent resistance, the above-mentioned lower equivalent resistance, the above-mentioned upper contact equivalent resistance, and the above-mentioned lower contact equivalent resistance; the above-mentioned determination of the noise voltage power spectrum density of the equivalent resistance of the above-mentioned sensor element based on the equivalent resistance of the above-mentioned sensor element; the above-mentioned determination of the noise voltage power spectrum density of the equivalent resistance of the above-mentioned primary winding based on the equivalent resistance of the above-mentioned primary winding; and the above-mentioned determination of the noise voltage power spectrum density of the equivalent resistance of the above-mentioned secondary winding based on the equivalent resistance of the above-mentioned secondary winding.

[0010] Optionally, the determining the noise floor of the MHD angular velocity sensor based on the noise voltage power spectral density of the MHD angular velocity sensor includes: determining the noise angular velocity power spectral density of the MHD angular velocity sensor based on the noise voltage power spectral density of the MHD angular velocity sensor; determining the noise angular position power spectral density of the MHD angular velocity sensor based on the noise angular velocity power spectral density of the MHD angular velocity sensor; determining a first noise floor index based on the noise angular velocity power spectral density of the MHD angular velocity sensor and a specified frequency range; determining a second noise floor index based on the noise angular position power spectral density of the MHD angular velocity sensor and the specified frequency range; wherein the first noise floor index and the second noise floor index characterize the noise floor of the MHD angular velocity sensor.

[0011] The present invention also provides a method for manufacturing a low-noise MHD angular velocity sensor, comprising: determining the shape data of each of the upper electrode, lower electrode, conductive fluid ring, magnetic core, magnet, primary winding, and secondary winding in the MHD angular velocity sensor based on shape constraints, wherein the shape data includes size data, material data, and shape data; determining the parameter values ​​of each of the multiple equivalent components included in the equivalent circuit model of the MHD angular velocity sensor based on the parameter values ​​of each of the multiple equivalent components and the shape parameters of the magnet; determining the noise angular velocity power spectrum density at the input end of the sensor element based on the parameter values ​​of the multiple equivalent components and the shape parameters of the magnet. degree; upon determining that the noise angular velocity power spectrum density at the input end of the above-mentioned sensing element meets the first predetermined noise angular velocity power spectrum density condition, determining the noise angular velocity power spectrum density of the above-mentioned MHD angular velocity sensor based on the parameter values ​​of each of the above-mentioned multiple equivalent devices and the turns ratio of the above-mentioned primary winding to the above-mentioned secondary winding; upon determining that the noise angular velocity power spectrum density of the above-mentioned MHD angular velocity sensor meets the second predetermined noise angular velocity power spectrum density condition, determining the gain of the amplifier; and manufacturing the above-mentioned MHD angular velocity sensor based on the respective external shape data of the above-mentioned upper electrode, the above-mentioned lower electrode, the above-mentioned conductive fluid ring, the above-mentioned magnetic core, the above-mentioned magnet, the above-mentioned primary winding and the above-mentioned secondary winding, the above-mentioned turns ratio, and the gain of the above-mentioned amplifier.

[0012] Optionally, the manufacturing method of a low-noise MHD angular velocity sensor further includes: when it is determined that the noise angular velocity power spectrum density at the input end of the above-mentioned sensor element does not meet the first predetermined noise angular velocity power spectrum density condition, adjusting the respective shape data of the above-mentioned upper electrode, the above-mentioned lower electrode, the above-mentioned conductive fluid ring, the above-mentioned magnetic core, the above-mentioned magnet, the above-mentioned primary winding and the above-mentioned secondary winding; and re-determining the noise angular velocity power spectrum density at the input end of the above-mentioned sensor element based on the adjusted respective shape data of the above-mentioned upper electrode, the above-mentioned lower electrode, the above-mentioned conductive fluid ring, the above-mentioned magnetic core, the above-mentioned magnet, the above-mentioned primary winding and the above-mentioned secondary winding.

[0013] Optionally, the method for manufacturing a low-noise MHD angular velocity sensor further includes: when it is determined that the noise angular velocity power spectrum density of the above-mentioned MHD angular velocity sensor does not meet a second predetermined noise angular velocity power spectrum density condition, adjusting the respective shape data of the above-mentioned upper electrode, the above-mentioned lower electrode, the above-mentioned conductive fluid ring, the above-mentioned magnetic core, the above-mentioned magnet, the above-mentioned primary winding and the above-mentioned secondary winding, and the above-mentioned turns ratio; based on the adjusted respective shape data of the above-mentioned upper electrode, the above-mentioned lower electrode, the above-mentioned conductive fluid ring, the above-mentioned magnetic core, the above-mentioned magnet, the above-mentioned primary winding and the above-mentioned secondary winding, re-determining the noise angular velocity power spectrum density of the above-mentioned MHD angular velocity sensor.

[0014] The present invention also provides an angular velocity detection method, comprising: obtaining an initial angular velocity detected by an MHD angular velocity sensor; updating the initial angular velocity based on the background noise of the MHD angular velocity sensor to obtain a target angular velocity; wherein the background noise of the MHD angular velocity sensor is determined using the background noise determination method for a low-noise MHD angular velocity sensor as described above.

[0015] According to embodiments of the present invention, based on the external shape data of the upper electrode, lower electrode, conductive fluid ring, magnetic core, primary winding, and secondary winding in an MHD angular velocity sensor, the parameter values ​​of the multiple equivalent components included in the equivalent circuit model of the MHD angular velocity sensor can be determined with high accuracy. Based on the parameter values ​​of the multiple equivalent components and the turns ratio of the primary winding to the secondary winding, the noise voltage power spectral density of the MHD angular velocity sensor can be determined with high accuracy, thereby accurately determining the noise floor of the MHD angular velocity sensor. When using the MHD angular velocity sensor to measure a payload platform, the measurement results of the MHD angular velocity sensor can be compensated based on the noise floor of the MHD angular velocity sensor. Using the compensated measurement results to control the payload can improve the stability of the payload's attitude and the accuracy of its pointing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0017] Figure 1 The flowchart of the method for determining the background noise of a low-noise MHD angular velocity sensor according to an embodiment of the present invention is schematically shown.

[0018] Figure 2 An exploded view of a sensing element and a transformer according to an embodiment of the present invention is shown.

[0019] Figure 3 A cross-sectional view of a sensing element and a transformer according to an embodiment of the present invention is shown.

[0020] Figure 4 FIG. 4 shows an equivalent circuit model of a sensing element according to an embodiment of the present invention.

[0021] Figure 5 FIG. 4 shows an equivalent circuit model of an MHD angular velocity sensor according to an embodiment of the present invention.

[0022] Figure 6 An equivalent circuit model of the MHD angular velocity sensor after adding a noise marker according to an embodiment of the present invention is shown.

[0023] Figure 7 The figure schematically shows an equivalent subcircuit model diagram of an amplifier according to an embodiment of the present invention.

[0024] Figure 8 The flowchart schematically shows a method for manufacturing a low-noise MHD angular velocity sensor according to an embodiment of the present invention.

[0025] Figure 9 The flowchart of the angular velocity detection method according to an embodiment of the present invention is schematically shown.

[0026] Reference numerals

[0027] 1. Outer casing; 2. Upper cover; 3. Outer cylinder; 4. Upper electrode; 5. Lower electrode; 6. Magnetic inner cylinder; 7. Upper isolating ring; 8. Lower isolating ring; 9. Upper permanent magnet; 10. Lower permanent magnet; 11. Upper magnetic yoke; 12. Lower magnetic yoke; 13. Upper magnetic ring; 14. Lower magnetic ring; 15. Conductive fluid ring; 16. Transformer; 161. Magnetic core; 162. Primary winding; 163. Secondary winding. DETAILED DESCRIPTION

[0028] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of embodiments of the present invention. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concept of the present invention.

[0029] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "comprise," "include," etc. used herein indicate the presence of features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0030] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0031] When expressions such as "at least one of A, B, and C, etc." are used, they should generally be interpreted in accordance with the meaning commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0032] The noise floor is a key parameter for measuring the ultimate resolution of an MHD angular rate sensor. It is determined by the sensor's internal sensor element and detection circuitry. However, calculating the noise floor involves complex electrical coupling between the sensor element and the detection circuitry. Typically, achieving the desired noise floor design target can only be achieved through empirical experimentation, increasing sensor design complexity, R&D cycle time, and manufacturing costs.

[0033] To address the above issues, embodiments of the present invention provide a low-noise method for determining the noise floor of an MHD angular velocity sensor. The method includes determining parameter values ​​for multiple equivalent components included in an equivalent circuit model of the MHD angular velocity sensor based on the shape data of the upper electrode, lower electrode, conductive fluid ring, primary winding, and secondary winding in the MHD angular velocity sensor. The shape data includes dimensional data, material data, and shape data. Based on the parameter values ​​of the multiple equivalent components and the turns ratio of the primary winding to the secondary winding, the noise voltage power spectral density of the MHD angular velocity sensor is determined. Based on the noise voltage power spectral density, the noise floor of the MHD angular velocity sensor is determined.

[0034] The following will be passed Figures 1 to 7 A method for determining the background noise of a low-noise MHD angular velocity sensor according to an embodiment of the present invention is described in detail.

[0035] Figure 1 The flowchart of the method for determining the background noise of a low-noise MHD angular velocity sensor according to an embodiment of the present invention is schematically shown. Figure 2 An exploded view of a sensing element and a transformer according to an embodiment of the present invention is shown. Figure 3 A cross-sectional view of a sensing element and a transformer according to an embodiment of the present invention is shown.

[0036] like Figure 1 As shown, the method 100 for determining the background noise of the low-noise MHD angular velocity sensor of this embodiment includes the following operations S110 to S130.

[0037] In operation S110 , parameter values ​​of a plurality of equivalent components included in an equivalent circuit model of the MHD angular velocity sensor are determined based on shape data of the upper electrode, lower electrode, conductive fluid ring, magnetic core, primary winding, and secondary winding of the MHD angular velocity sensor.

[0038] According to embodiments of the present invention, shape data can be data that affects the performance of various physical components in an MHD angular velocity sensor. For example, this data can affect the conductivity of the upper electrode, lower electrode, conductive fluid ring, primary winding, and secondary winding, as well as data that affects the magnetic properties of the magnetic core. Shape data can include dimensional data, material data, and shape data. Dimensional data can include length, height, width, and cross-sectional area. Material data can include copper, iron, and aluminum. Shape data can include cylindrical, tubular, annular, and winding direction.

[0039] According to an embodiment of the present invention, the MHD angular velocity sensor may be composed of a sensing element, a transformer, and an amplifier. The sensing element may convert the external angular velocity input into a motional electromotive force output. Figure 2 and Figure 3As shown, the sensor element may include physical components such as a housing 1, an upper cover 2, an outer cylinder 3, an upper electrode 4, a lower electrode 5, a magnetic inner cylinder 6, an upper isolating ring 7, a lower isolating ring 8, a magnet, an upper magnetic yoke 11, a lower magnetic yoke 12, an upper magnetic ring 13, and a lower magnetic ring 14. The magnet may include an upper permanent magnet 9 and a lower permanent magnet 10. The housing 1 and the upper cover 2 may form an enclosed space. The outer cylinder 3 may be disposed within the enclosed space. The upper electrode 4 and the lower electrode 5 may be located at the top and bottom of the outer cylinder 3, respectively. The upper electrode 4 and the lower electrode 5 may be cap-shaped. The magnetic inner cylinder 6 may be disposed between the upper electrode 4 and the lower electrode 5, and positioned at the brim of the cap. A conductive fluid may be filled between the inner wall of the outer cylinder 3 and the outer wall of the magnetic inner cylinder 6, thereby forming a conductive fluid ring 15. The upper electrode 4 and the lower electrode 5 may each be provided with a through hole. The upper isolating ring 7, the lower isolating ring 8, the upper magnetic yoke 11, and the lower magnetic yoke 12 may be disposed in the through holes, respectively. An upper permanent magnet 9 and a lower permanent magnet 10 are provided in the upper isolation ring 7 and the lower isolation ring 8. The transformer 16 can be provided between the upper electrode 4 and the lower electrode 5 and located at the cap body. The transformer 16 can be composed of a magnetic core 161, a primary winding 162 and a secondary winding 163. The upper magnetic ring 13 and the lower magnetic ring 14 can be respectively sleeved on the upper magnetic yoke 11 and the lower magnetic yoke 12. The transformer 16 can be provided inside the sensing element. The secondary winding 163 can be wound on the magnetic core 161, and the primary winding 162 can be wound on the secondary winding 163. The conductive fluid can generate an electrical signal under the action of the external angular velocity. The electrical signal can flow out of the conductive fluid ring 15, flow through the upper electrode 4, the primary winding 162 and the lower electrode 5, and return to the conductive fluid ring 15, thereby forming a current path in the sensing element.

[0040] According to an embodiment of the present invention, an equivalent circuit model of the MHD angular velocity sensor can be used to represent the electrical characteristics of the MHD angular velocity sensor. The equivalent circuit model can be a resistance model, an impedance model, and / or a mutual inductance model.

[0041] According to an embodiment of the present invention, an equivalent device can be used to simulate the electrical characteristics of each physical device in an MHD angular velocity sensor. The parameter value of the equivalent device can represent the specific electrical characteristics of the physical device.

[0042] In operation S120 , a noise voltage power spectrum density of the MHD angular velocity sensor is determined based on parameter values ​​of the respective equivalent devices and a turns ratio of the primary winding to the secondary winding.

[0043] In operation S130 , a noise floor of the MHD angular velocity sensor is determined based on a noise voltage power spectrum density of the MHD angular velocity sensor.

[0044] According to embodiments of the present invention, based on the external shape data of the upper electrode, lower electrode, conductive fluid ring, magnetic core, primary winding, and secondary winding in an MHD angular velocity sensor, the parameter values ​​of the multiple equivalent components included in the equivalent circuit model of the MHD angular velocity sensor can be determined with high accuracy. Based on the parameter values ​​of the multiple equivalent components and the turns ratio of the primary winding to the secondary winding, the noise voltage power spectral density of the MHD angular velocity sensor can be determined with high accuracy, thereby accurately determining the noise floor of the MHD angular velocity sensor. When using the MHD angular velocity sensor to measure a payload platform, the measurement results of the MHD angular velocity sensor can be compensated based on the noise floor of the MHD angular velocity sensor. Using the compensated measurement results to control the payload can improve the stability of the payload's attitude and the accuracy of its pointing.

[0045] Figure 4 FIG. 4 shows an equivalent circuit model of a sensing element according to an embodiment of the present invention. Figure 5 FIG. 4 shows an equivalent circuit model of an MHD angular velocity sensor according to an embodiment of the present invention. Figure 6 An equivalent circuit model of the MHD angular velocity sensor after adding a noise marker according to an embodiment of the present invention is shown.

[0046] In some embodiments, the plurality of equivalent components may include a conductive equivalent resistor, an upper equivalent resistor, a lower equivalent resistor, an upper contact equivalent resistor, a lower contact equivalent resistor, an equivalent resistance of a primary winding, an equivalent inductance of a primary winding, and an equivalent resistance of a secondary winding.

[0047] According to an embodiment of the present invention, Figure 4 As shown, the equivalent device in the sensing element may include a voltage source , conductive equivalent resistance , upper equivalent resistance (not shown in the figure), lower equivalent resistance (not shown in the figure), upper contact equivalent resistance (not shown in the figure), lower contact equivalent resistance (not shown in the figure) and stray inductance .

[0048] According to an embodiment of the present invention, the voltage source It can characterize the alternating electromotive force generated by the conductive fluid ring sensitive to the external input angular velocity. It can characterize the equivalent resistance of the conductive fluid ring, that is, the conductive equivalent resistance It can characterize the axial equivalent resistance between the upper and lower end surfaces of the conductive fluid ring.

[0049] According to an embodiment of the present invention, the upper equivalent resistance can represent the equivalent resistance of the upper electrode in the current path of the MHD angular velocity sensor, that is, it can be the equivalent resistance in the current path in the sensor element. The lower equivalent resistance can represent the equivalent resistance of the lower electrode in the current path. Figure 4 As shown, the upper equivalent resistance and the lower equivalent resistance can be obtained by the electrode equivalent resistance Indicates the electrode equivalent resistance. It can be the sum of the upper equivalent resistance and the lower equivalent resistance.

[0050] According to an embodiment of the present invention, the upper contact equivalent resistance can represent the equivalent resistance of the contact surface between the conductive fluid ring and the upper electrode. The lower contact equivalent resistance can represent the equivalent resistance of the contact surface between the conductive fluid ring and the lower electrode. Figure 4 As shown, the upper contact equivalent resistance and the lower contact equivalent resistance can be expressed by the contact equivalent resistance Indicates. Contact equivalent resistance It can be the sum of the upper contact equivalent resistance and the lower contact equivalent resistance.

[0051] Furthermore, the conductive equivalent resistance , electrode equivalent resistance And the contact equivalent resistance The equivalent resistance of the sensing element can be express.

[0052] Furthermore, the stray inductance It is formed by the current path surrounding the magnetic inner cylinder. It can be shown as the following formula (1).

[0053] (1).

[0054] in, It can be the vacuum permeability. It can be the relative magnetic permeability of the magnetic inner cylinder. It can be the height of the magnetic inner cylinder. It can be the outer diameter of the magnetic inner cylinder. It can be the inner diameter of the magnetic inner cylinder.

[0055] Furthermore, in the signal bandwidth range of 0.1Hz~1kHz, under the condition of voltage signal source amplitude of tens of microvolts, due to stray inductance The energy storage is very small, stray inductance can be ignored. Thus, we can get Figure 5 The equivalent circuit model of the MHD angular velocity sensor is shown.

[0056] like Figure 5 As shown, according to an embodiment of the present invention, the equivalent device in the transformer may include an equivalent resistor of the primary winding. , the equivalent inductance of the primary winding and the equivalent resistance of the secondary winding The equivalent resistance of the primary winding is The equivalent DC resistance of the primary winding can be expressed as: The equivalent magnetizing inductance of the primary winding can be expressed as: It can be the equivalent DC resistance of the secondary winding. It can be expressed as the output voltage of the MHD angular velocity sensor.

[0057] Furthermore, within the signal bandwidth range of 0.1Hz~1kHz, the voltage noise output by the sensor element can be due to the equivalent resistance of the sensor element. The thermal noise generated, the voltage noise output by the sensing element can be expressed as The voltage noise of the primary winding output can be due to the equivalent resistance of the primary winding. The thermal noise generated, the voltage noise output by the primary winding can be expressed as The voltage noise of the secondary winding output can be due to the equivalent resistance of the secondary winding. The thermal noise generated, the voltage noise output by the secondary winding can be expressed as The input voltage noise of the amplifier and the equivalent input current noise of the amplifier can be obtained from the workbook of the selected amplifier. The input voltage noise of the amplifier can be expressed as The equivalent input current noise of the amplifier can be expressed as . Thus we can get Figure 6 The equivalent circuit model of the MHD angular velocity sensor shown in the figure is added with noise markers. It can be expressed as the voltage noise output by the MHD angular velocity sensor.

[0058] In some embodiments, operation S110 may include the following operations S111 to S118.

[0059] In operation S111 , a parameter value of a conductive equivalent resistance is determined based on the shape data of the conductive fluid ring.

[0060] According to an embodiment of the present invention, the parameter value of the conductive equivalent resistance can be the resistance value of the conductive equivalent resistance, which can be calculated based on the shape data of the conductive fluid ring using the resistance law. For example, the parameter value of the conductive equivalent resistance is It can be expressed by the following formula (2).

[0061] (2).

[0062] in, Can be the height of the conductive fluid ring. This can be the outer diameter of the conductive fluid ring. This can be the inner diameter of the conductive fluid ring. It can be the conductivity of the conductive fluid.

[0063] In operation S112 , a parameter value of the upper equivalent resistor is determined based on the outer shape data of the upper electrode.

[0064] According to an embodiment of the present invention, the parameter value of the upper equivalent resistor may be the resistance value of the upper equivalent resistor, which may be calculated using a numerical method, for example, by a finite element method based on the shape data of the upper electrode.

[0065] In operation S113 , a parameter value of the lower equivalent resistor is determined based on the shape data of the lower electrode.

[0066] According to an embodiment of the present invention, the parameter value of the lower equivalent resistor may be the resistance value of the lower equivalent resistor, which may be calculated using a numerical method, for example, by a finite element method based on the shape data of the lower electrode.

[0067] In operation S114 , a parameter value of the upper contact equivalent resistance is determined based on the respective shape data of the upper electrode and the conductive fluid ring.

[0068] According to an embodiment of the present invention, the parameter value of the upper contact equivalent resistance can be the resistance value of the upper contact equivalent resistance, which can be calculated using a numerical method. For example, it can be calculated using a finite element method based on the respective shape data of the upper electrode and the conductive fluid ring.

[0069] In operation S115 , a parameter value of the lower contact equivalent resistance is determined based on the respective shape data of the lower electrode and the conductive fluid ring.

[0070] According to an embodiment of the present invention, the parameter value of the lower contact equivalent resistance can be the resistance value of the lower contact equivalent resistance, which can be calculated using a numerical method. For example, it can be calculated using a finite element method based on the respective shape data of the lower electrode and the conductive fluid ring.

[0071] In operation S116 , a parameter value of an equivalent resistance of the primary winding is determined based on the shape data of the primary winding.

[0072] According to an embodiment of the present invention, the parameter value of the equivalent resistance of the primary winding may be the resistance value of the equivalent resistance of the primary winding, which may be calculated based on the shape data of the primary winding using the basic resistance formula. For example, the resistance value of the equivalent resistance of the primary winding is It can be expressed by the following formula (3).

[0073] (3).

[0074] in, This may be the resistivity of the material of the primary winding. Can be the length of the primary winding. This can be the cross-sectional area of ​​the conductor after the primary winding is wound around the magnetic core.

[0075] In operation S117 , a parameter value of an equivalent resistance of the secondary winding is determined based on the shape data of the secondary winding.

[0076] According to an embodiment of the present invention, the parameter value of the equivalent resistance of the secondary winding may be the resistance value of the equivalent resistance of the secondary winding, which may be calculated based on the shape data of the secondary winding using the basic resistance formula. For example, the resistance value of the equivalent resistance of the secondary winding is It can be expressed by the following formula (4).

[0077] (4).

[0078] in, This may be the resistivity of the material of the secondary winding. Can be the length of the secondary winding. It can be the cross-sectional area of ​​the conductor after the secondary winding is wound.

[0079] In operation S118 , a parameter value of an equivalent inductance of the primary winding is determined based on the shape data of the magnetic core, the shape data of the primary winding, and the number of turns of the primary winding.

[0080] According to an embodiment of the present invention, the parameter value of the equivalent inductance of the primary winding may be the inductance value of the equivalent inductance of the primary winding, which may be calculated using an electromagnetic calculation formula based on the shape data of the magnetic core and the number of turns of the primary winding. For example, the inductance value of the equivalent inductance of the primary winding is It can be expressed by the following formula (5).

[0081] (5).

[0082] in, Can be the number of primary turns. It can be the magnetic permeability of the magnetic core. It can be the cross-sectional area of ​​the core. The average length of the magnetic circuit can be obtained based on the shape data of the magnetic core, the magnetic permeability of the magnetic core, the cross-sectional area of ​​the magnetic core and the average length of the magnetic circuit.

[0083] In some embodiments, the equivalent circuit model may be composed of a sensor element, a transformer, and an amplifier. Operation S120 may include the following operations S121 to S123.

[0084] In operation S121 , noise voltage power spectrum density of an equivalent resistance of a sensing element, an equivalent resistance of a primary winding, and an equivalent resistance of a secondary winding are determined based on parameter values ​​of respective equivalent devices.

[0085] In operation S122 , a low-frequency cutoff frequency after the transformer and the amplifier are connected is determined based on an equivalent resistance of the sensing element, an equivalent resistance of the primary winding, and an equivalent inductance of the primary winding.

[0086] According to an embodiment of the present invention, the low-frequency cutoff frequency after the transformer and the amplifier are connected is It can be expressed by the following formula (6).

[0087] (6).

[0088] in, It can be the equivalent resistance of the primary winding. It can be the equivalent resistance of the sensing element.

[0089] In operation S123, a noise voltage power spectral density of the MHD angular velocity sensor is determined based on the gain of the amplifier, the noise voltage power spectral density of the amplifier, the low-frequency cutoff frequency after the transformer and the amplifier are connected, the turns ratio, the noise voltage power spectral density of the equivalent resistance of the sensing element, the noise voltage power spectral density of the equivalent resistance of the primary winding, and the noise voltage power spectral density of the equivalent resistance of the secondary winding.

[0090] According to an embodiment of the present invention, the noise voltage power spectrum density of the MHD angular velocity sensor is It can be expressed by the following formula (7).

[0091] (7).

[0092] in, is the transfer function after the transformer and amplifier are connected in the MHD angular velocity sensor. Can be a complex frequency. It can be the angular frequency. Can be an imaginary unit. The noise voltage power spectral density can be the equivalent resistance of the sensing element. The noise voltage power spectral density can be expressed as the equivalent resistance of the primary winding. The noise voltage power spectral density can be expressed as the equivalent resistance of the secondary winding. It can be the noise voltage power spectral density of the amplifier. It can be the noise current power spectral density of the amplifier. It can be obtained from the equivalent input voltage noise of the amplifier. It can be obtained from the equivalent input current noise of the amplifier. It can be the gain of the amplifier. It can be the turns ratio of the primary winding to the secondary winding.

[0093] Furthermore, the transfer function of the transformer and amplifier in the MHD angular velocity sensor is It can be expressed by the following formula (8).

[0094] (8).

[0095] Figure 7 The figure schematically shows an equivalent subcircuit model diagram of an amplifier according to an embodiment of the present invention.

[0096] like Figure 7 As shown, the amplifier can be an active amplifier. The active amplifier can be provided with three operational amplifiers. The equivalent subcircuit model includes a first operational amplifier , the second operational amplifier , the third operational amplifier , the first resistor , the second resistor , the third resistor , the fourth resistor , the fifth resistor , the sixth resistor , the seventh resistor , the eighth resistor , the ninth resistor and the first capacitor . The first resistor , the second resistor and the third resistor The fourth resistor is connected in series to form the first branch. , the fifth resistor and the first capacitor The sixth resistor is connected in series to form the second branch. , the seventh resistor and the third operational amplifier A third branch is formed. The third operational amplifier The output of the third operational amplifier is used as the output of the active amplifier. The output terminal and the sixth resistor An eighth resistor is provided between The first branch, the second branch and the third branch are connected in parallel. The first operational amplifier The negative input terminal is connected to the first resistor and the second resistor The second operational amplifier The negative input terminal is connected to the third resistor and the second resistor The first operational amplifier The output terminal is connected to the first resistor and the fourth resistor The second operational amplifier The output terminal is connected to the third resistor and the fifth resistor between.

[0097] Furthermore, the gain of the amplifier It can be expressed by the following formula (9).

[0098] (9).

[0099] In some embodiments, operation S121 may include the following operations S1211 to S1214.

[0100] In operation S1211 , an equivalent resistance of a sensing element in an equivalent circuit model of the MHD angular velocity sensor is obtained based on the conductive equivalent resistance, the upper equivalent resistance, the lower equivalent resistance, the upper contact equivalent resistance, and the lower contact equivalent resistance.

[0101] According to an embodiment of the present invention, the equivalent resistance of the sensing element It can be shown as the following formula (10).

[0102] (10).

[0103] In operation S1212 , a noise voltage power spectrum density of the equivalent resistance of the sensing element is determined based on the equivalent resistance of the sensing element.

[0104] According to an embodiment of the present invention, the noise voltage power spectrum density of the equivalent resistance of the sensing element is It can be shown as the following formula (11).

[0105] (11).

[0106] in, can be the Boltzmann constant, Can be the absolute temperature of the sensing element.

[0107] In operation S1213 , based on the equivalent resistance of the primary winding, a noise voltage power spectrum density of the equivalent resistance of the primary winding is determined.

[0108] According to an embodiment of the present invention, the noise voltage power spectrum density of the equivalent resistance of the primary winding is It can be shown as the following formula (12).

[0109] (12).

[0110] in, It can be the absolute temperature of the primary winding.

[0111] In operation S1214 , a noise voltage power spectrum density of the equivalent resistance of the secondary winding is determined based on the equivalent resistance of the secondary winding.

[0112] According to an embodiment of the present invention, the noise voltage power spectrum density of the equivalent resistance of the secondary winding is It can be shown as the following formula (13).

[0113] (13).

[0114] in, Can be the absolute temperature of the secondary winding.

[0115] In some embodiments, operation S130 may include the following operations S131 to S134.

[0116] In operation S131 , a noise angular velocity power spectrum density of the MHD angular velocity sensor is determined based on a noise voltage power spectrum density of the MHD angular velocity sensor.

[0117] According to the embodiment of the present invention, the absolute temperature of the entire MHD angular velocity sensor is ,Right now , the noise angular velocity power spectrum density of the MHD angular velocity sensor It can be shown as the following formula (14).

[0118] (14).

[0119] in, It can be the amplitude-frequency response function of the sensing element.

[0120] Furthermore, the amplitude-frequency response function of the sensor element It can be expressed by the following formula (15).

[0121] (15).

[0122] in, It can be the average magnetic induction intensity within the conductive fluid ring. Average magnetic induction intensity It can be expressed by the following formula (16).

[0123] (16).

[0124] in, can be the working point flux density of the magnet, can be the pole area of ​​the magnet, It can be the leakage coefficient of the magnetic circuit, for example The magnetic flux density at the working point and the magnetic pole area of ​​the magnet can be obtained based on the magnet's shape parameters. The magnet's shape parameters may include the magnet's material, magnet's size, magnet's shape, and magnetization intensity.

[0125] In operation S132 , a noise angular position power spectrum density of the MHD angular velocity sensor is determined based on the noise angular velocity power spectrum density of the MHD angular velocity sensor.

[0126] According to an embodiment of the present invention, the noise angular position power spectrum density of the MHD angular velocity sensor is It can be shown as the following formula (17).

[0127] (17).

[0128] in, It can be the angular frequency.

[0129] In operation S133 , a first noise floor index is determined based on a noise angular velocity power spectrum density and a designated frequency range of the MHD angular velocity sensor.

[0130] According to an embodiment of the present invention, the first background noise index It can be shown as the following formula (18).

[0131] (18).

[0132] The specified frequency range is f1 to f2. f1 is greater than 0. f2 is greater than 0.

[0133] In operation S134 , a second noise floor index is determined based on the noise angular position power spectrum density of the MHD angular velocity sensor and a designated frequency range.

[0134] According to an embodiment of the present invention, the second background noise index It can be shown as the following formula (19).

[0135] (19).

[0136] The first noise floor index and the second noise floor index can represent the noise floor of the MHD angular velocity sensor. The first noise floor index can be the positive square root of the noise equivalent angular velocity. The second noise floor index can be the positive square root of the noise equivalent angular position.

[0137] Figure 8 The flowchart schematically shows a method for manufacturing a low-noise MHD angular velocity sensor according to an embodiment of the present invention.

[0138] like Figure 8As shown, the method 800 for manufacturing a low-noise MHD angular velocity sensor according to this embodiment includes the following operations S810 to S860.

[0139] In operation S810 , shape data of each of an upper electrode, a lower electrode, a conductive fluid ring, a magnetic core, a magnet, a primary winding, and a secondary winding in the MHD angular velocity sensor are determined based on shape constraints.

[0140] According to an embodiment of the present invention, the appearance data may include size data, material data, and shape data.

[0141] According to an embodiment of the present invention, the shape constraint condition can be that the shape data of the upper electrode, lower electrode, conductive fluid ring, magnetic core, magnet, primary winding and secondary winding in the MHD angular velocity sensor meet the shape size limit requirements of the MHD angular velocity sensor.

[0142] In operation S820 , parameter values ​​of a plurality of equivalent components included in an equivalent circuit model of the MHD angular velocity sensor are determined based on the shape data of the upper electrode, lower electrode, conductive fluid ring, magnetic core, magnet, primary winding, and secondary winding in the MHD angular velocity sensor.

[0143] According to an embodiment of the present invention, parameter values ​​of the multiple equivalent components included in the equivalent circuit model of the MHD angular velocity sensor may be determined in the same manner as in operations S110 to S118 .

[0144] In operation S830 , a noise angular velocity power spectrum density at an input terminal of the sensing element is determined based on parameter values ​​of each of the plurality of equivalent devices.

[0145] According to an embodiment of the present invention, the noise voltage power spectral density generated within the current path after the sensing element is coupled to the transformer can be determined based on parameter values ​​of multiple equivalent devices. The noise angular velocity power spectral density at the input of the sensing element can also be determined based on the noise voltage power spectral density generated within the current path after the sensing element is coupled to the transformer.

[0146] Furthermore, the noise voltage power spectrum density generated in the current path after the sensing element is coupled with the transformer is It can be shown as the following formula (20).

[0147] (20).

[0148] According to an embodiment of the present invention, the noise angular velocity power spectrum density at the input end of the sensor element is It can be shown as the following formula (21).

[0149] (twenty one).

[0150] In operation S840, when it is determined that the noise angular velocity power spectrum density at the input end of the sensing element satisfies a first predetermined noise angular velocity power spectrum density condition, the noise angular velocity power spectrum density of the MHD angular velocity sensor is determined based on parameter values ​​of respective equivalent components and a turns ratio of the primary winding to the secondary winding.

[0151] According to an embodiment of the present invention, the first predetermined noise angular velocity power spectrum density condition may be that the noise angular velocity power spectrum density at the input end of the sensor element is less than half of a design index of the noise equivalent angular velocity power spectrum density within the passband. The design index of the noise equivalent angular velocity power spectrum density may be set based on prior experience.

[0152] According to an embodiment of the present invention, the noise angular velocity power spectrum density of the MHD angular velocity sensor is It can be shown as the following formula (22).

[0153] (twenty two).

[0154] in, is the number of turns of the primary winding, is the number of secondary turns, is the average single-turn resistance of the primary winding, is the average single-turn resistance of the secondary winding.

[0155] In operation S850 , if it is determined that the noise angular velocity power spectrum density of the MHD angular velocity sensor satisfies a second predetermined noise angular velocity power spectrum density condition, a gain of the amplifier is determined.

[0156] According to an embodiment of the present invention, the second predetermined noise angular velocity power spectral density condition may be a condition that meets normal operating requirements of the MHD angular velocity sensor. For example, the second predetermined noise angular velocity power spectral density condition may be that the noise angular velocity power spectral density of the MHD angular velocity sensor is less than 80 percent of a design index of the noise equivalent angular velocity power spectral density within the passband. The design index of the noise equivalent angular velocity power spectral density may be set based on prior experience.

[0157] According to an embodiment of the present invention, the gain of the amplifier It can be shown as the following formula (23).

[0158] (twenty three).

[0159] in, The maximum output voltage swing of the MHD angular velocity sensor can be It can be the angular rate range indicator of the MHD angular rate sensor. It can be the average magnetic induction intensity within the conductive fluid ring. . Can be the height of the conductive fluid ring. It can be the optimal turns ratio of the amplifier.

[0160] In operation S860 , an MHD angular velocity sensor is manufactured based on the shape data of each of the upper electrode, the lower electrode, the conductive fluid ring, the magnetic core, the magnet, the primary winding, and the secondary winding, the turns ratio, and the gain of the amplifier.

[0161] According to an embodiment of the present invention, in formula (22), the minimum value method can be used to find Place, seek right The partial derivative of , set the partial derivative to 0, and find the optimal turns ratio And the optimal noise equivalent angular rate power spectrum density. Update the turns ratio to the optimal turns ratio Noise angular velocity power spectral density The optimal noise equivalent angular rate power spectral density is updated, and the updated noise angular velocity power spectral density is used to determine whether a second predetermined noise angular velocity power spectral density condition is satisfied. After the second predetermined noise angular velocity power spectral density condition is satisfied, the updated turns ratio is used to manufacture the MHD angular velocity sensor.

[0162] According to the embodiment of the present invention, an MHD angular velocity sensor is manufactured using a low-noise MHD angular velocity sensor manufacturing method, which can shorten the development cycle of the MHD angular velocity sensor and reduce the development cost.

[0163] In some embodiments, the method for manufacturing a low-noise MHD angular velocity sensor may further include: if it is determined that the noise angular velocity power spectral density at the input end of the sensing element does not meet a first predetermined noise angular velocity power spectral density condition, adjusting the shape data of the upper electrode, the lower electrode, the conductive fluid ring, the magnetic core, the magnet, the primary winding, and the secondary winding. Based on the adjusted shape data of the upper electrode, the lower electrode, the conductive fluid ring, the magnetic core, the magnet, the primary winding, and the secondary winding, the noise angular velocity power spectral density at the input end of the sensing element is re-determined.

[0164] According to an embodiment of the present invention, adjusting the shape data of the upper electrode, lower electrode, conductive fluid ring, magnetic core, magnet, primary winding, and secondary winding can be performed by increasing the size of the shape data of the upper electrode, lower electrode, conductive fluid ring, magnetic core, primary winding, and secondary winding, thereby reducing the noise angular velocity power spectral density at the input end of the sensor element. By increasing the shape data of the magnet, the average magnetic induction intensity within the conductive fluid ring can be increased, thereby reducing the noise angular velocity power spectral density at the input end of the sensor element.

[0165] In some embodiments, the method for manufacturing a low-noise MHD angular velocity sensor may further include: if it is determined that the noise angular velocity power spectral density of the MHD angular velocity sensor does not meet a second predetermined noise angular velocity power spectral density condition, adjusting the shape data and turns ratio of each of the upper electrode, the lower electrode, the conductive fluid ring, the magnetic core, the magnet, the primary winding, and the secondary winding. Based on the adjusted shape data and turns ratio of each of the upper electrode, the lower electrode, the conductive fluid ring, the magnetic core, the magnet, the primary winding, and the secondary winding, the noise angular velocity power spectral density of the MHD angular velocity sensor is re-determined.

[0166] According to an embodiment of the present invention, adjusting the shape data and turns ratio of the upper electrode, lower electrode, conductive fluid ring, magnetic core, magnet, primary winding, and secondary winding can increase the size of the shape data of the upper electrode, lower electrode, conductive fluid ring, magnetic core, magnet, primary winding, and secondary winding, thereby reducing the noise angular velocity power spectral density of the MHD angular velocity sensor. By increasing the shape data of the magnet, the average magnetic induction intensity within the conductive fluid ring can be increased, thereby reducing the noise angular velocity power spectral density of the MHD angular velocity sensor.

[0167] Figure 9 The flowchart of the angular velocity detection method according to an embodiment of the present invention is schematically shown.

[0168] like Figure 9 As shown, the angular velocity detection method 900 of this embodiment includes the following operations S910 to S920.

[0169] In operation S910 , an initial angular velocity detected by the MHD angular velocity sensor is acquired.

[0170] In operation S920 , the initial angular velocity is updated based on the background noise of the MHD angular velocity sensor to obtain a target angular velocity.

[0171] According to an embodiment of the present invention, the noise floor of the MHD angular velocity sensor is determined using the noise floor determination method of the low-noise MHD angular velocity sensor as described above.

[0172] According to embodiments of the present invention, by updating the initial angular velocity based on the noise floor of the MHD angular velocity sensor, the MHD angular velocity sensor's measurement results can be compensated to obtain a target angular velocity that eliminates the influence of the noise floor. Using this compensated target angular velocity to control the payload improves payload attitude stability and pointing accuracy.

[0173] The flow chart in the accompanying drawings illustrates the functions that may be realized according to the method of various embodiments of the present invention. In this regard, each box in the flow chart can represent a module, program segment, or a part of code, and the part of the above-mentioned module, program segment, or code comprises one or more executable instructions for realizing the logical function of the specification. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a sequence different from that marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the flow chart, and the combination of the boxes in the flow chart, can be realized by a special hardware-based system that performs the function or operation of the specification, or can be realized by a combination of special hardware and computer instructions.

[0174] Those skilled in the art will appreciate that various combinations and / or combinations of features described in the various embodiments and / or claims of the present invention may be made, even if such combinations and / or combinations are not explicitly described in the present invention. In particular, various combinations and / or combinations of features described in the various embodiments and / or claims of the present invention may be made, without departing from the spirit and teachings of the present invention. All such combinations and / or combinations fall within the scope of the present invention.

[0175] The above describes embodiments of the present invention. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Although each embodiment has been described separately above, this does not mean that the measures in each embodiment cannot be advantageously used in combination. The scope of the present invention is defined by the appended claims and their equivalents. Without departing from the scope of the present invention, those skilled in the art may make various substitutions and modifications, which are intended to fall within the scope of the present invention.

Claims

1. A method for determining the background noise of a low-noise MHD angular velocity sensor, characterized in that: include: Determining parameter values ​​of a plurality of equivalent components included in an equivalent circuit model of the MHD angular velocity sensor based on respective shape data of an upper electrode, a lower electrode, a conductive fluid ring, a magnetic core, a primary winding, and a secondary winding in the MHD angular velocity sensor, wherein the shape data includes size data, material data, and shape data; determining a noise voltage power spectrum density of the MHD angular velocity sensor based on parameter values ​​of the respective equivalent components and a turns ratio of the primary winding to the secondary winding; The background noise of the MHD angular velocity sensor is determined based on the noise voltage power spectral density of the MHD angular velocity sensor.

2. The method for determining the background noise of a low-noise MHD angular velocity sensor according to claim 1, characterized in that: The multiple equivalent devices include a conductive equivalent resistance, an upper equivalent resistance, a lower equivalent resistance, an upper contact equivalent resistance, a lower contact equivalent resistance, an equivalent resistance of the primary winding, an equivalent inductance of the primary winding, and an equivalent resistance of the secondary winding, wherein the conductive equivalent resistance represents the equivalent resistance of the conductive fluid ring, the upper equivalent resistance represents the equivalent resistance of the upper electrode in the current path of the MHD angular velocity sensor, the lower equivalent resistance represents the equivalent resistance of the lower electrode in the current path, the upper contact equivalent resistance represents the equivalent resistance of the contact surface between the conductive fluid ring and the upper electrode, and the lower contact equivalent resistance represents the equivalent resistance of the contact surface between the conductive fluid ring and the lower electrode.

3. The method for determining the background noise of a low-noise MHD angular velocity sensor according to claim 2, characterized in that: The method of determining the parameter values ​​of the multiple equivalent components included in the equivalent circuit model of the MHD angular velocity sensor based on the shape data of the upper electrode, the lower electrode, the conductive fluid ring, the magnetic core, the primary winding and the secondary winding in the MHD angular velocity sensor comprises: Determining a parameter value of conductive equivalent resistance based on the shape data of the conductive fluid ring; Determining a parameter value of the upper equivalent resistor based on the shape data of the upper electrode; Determining a parameter value of the lower equivalent resistance based on the shape data of the lower electrode; Determining a parameter value of the upper contact equivalent resistance based on the respective shape data of the upper electrode and the conductive fluid ring; Determining a parameter value of the lower contact equivalent resistance based on the respective shape data of the lower electrode and the conductive fluid ring; Determining a parameter value of an equivalent resistance of the primary winding based on the shape data of the primary winding; Determining a parameter value of an equivalent resistance of the secondary winding based on the shape data of the secondary winding; Based on the shape data of the magnetic core and the number of turns of the primary winding, a parameter value of the equivalent inductance of the primary winding is determined.

4. The method for determining the background noise of a low-noise MHD angular velocity sensor according to claim 2, characterized in that: The equivalent circuit model is composed of a sensor element, a transformer and an amplifier; The step of determining the noise voltage power spectrum density of the MHD angular velocity sensor based on respective parameter values ​​of a plurality of equivalent components and a turns ratio of the primary winding to the secondary winding comprises: Determining the noise voltage power spectrum density of the equivalent resistance of the sensing element, the noise voltage power spectrum density of the equivalent resistance of the primary winding, and the noise voltage power spectrum density of the equivalent resistance of the secondary winding based on the respective parameter values ​​of the multiple equivalent devices; Determining a low-frequency cutoff frequency after the transformer and the amplifier are connected based on an equivalent resistance of the sensor element, an equivalent resistance of the primary winding, and an equivalent inductance of the primary winding; The noise voltage power spectral density of the MHD angular velocity sensor is determined based on the gain of the amplifier, the noise voltage power spectral density of the amplifier, the low-frequency cutoff frequency after the transformer and the amplifier are connected, the turns ratio, the noise voltage power spectral density of the equivalent resistance of the sensor element, the noise voltage power spectral density of the equivalent resistance of the primary winding, and the noise voltage power spectral density of the equivalent resistance of the secondary winding.

5. The method for determining the background noise of a low-noise MHD angular velocity sensor according to claim 4, characterized in that: The determining, based on the parameter values ​​of the multiple equivalent devices, the noise voltage power spectrum density of the equivalent resistance of the sensing element, the noise voltage power spectrum density of the equivalent resistance of the primary winding, and the noise voltage power spectrum density of the equivalent resistance of the secondary winding comprises: Based on the conductive equivalent resistance, the upper equivalent resistance, the lower equivalent resistance, the upper contact equivalent resistance and the lower contact equivalent resistance, an equivalent resistance of a sensing element in an equivalent circuit model of the MHD angular velocity sensor is obtained; Determining the noise voltage power spectrum density of the equivalent resistance of the sensing element based on the equivalent resistance of the sensing element; Determining the noise voltage power spectrum density of the equivalent resistance of the primary winding based on the equivalent resistance of the primary winding; The noise voltage power spectrum density of the equivalent resistance of the secondary winding is determined based on the equivalent resistance of the secondary winding.

6. The method for determining the background noise of a low-noise MHD angular velocity sensor according to claim 1, characterized in that: The step of determining the background noise of the MHD angular velocity sensor based on the noise voltage power spectrum density of the MHD angular velocity sensor comprises: Determining a noise angular velocity power spectral density of the MHD angular velocity sensor based on a noise voltage power spectral density of the MHD angular velocity sensor; Determining a noise angular position power spectral density of the MHD angular velocity sensor based on the noise angular velocity power spectral density of the MHD angular velocity sensor; Determining a first background noise index based on a noise angular velocity power spectrum density and a specified frequency range of the MHD angular velocity sensor; Determining a second background noise index based on the noise angular position power spectrum density of the MHD angular velocity sensor and the specified frequency range; The first background noise index and the second background noise index represent the background noise of the MHD angular velocity sensor.

7. A method for manufacturing a low-noise MHD angular velocity sensor, characterized in that: include: Based on the shape constraint condition, determining the shape data of the upper electrode, the lower electrode, the conductive fluid ring, the magnetic core, the magnet, the primary winding and the secondary winding in the MHD angular velocity sensor, respectively, wherein the shape data includes size data, material data and shape data; Determine the parameter values ​​of the multiple equivalent components included in the equivalent circuit model of the MHD angular velocity sensor based on the shape data of the upper electrode, the lower electrode, the conductive fluid ring, the magnetic core, the magnet, the primary winding and the secondary winding in the MHD angular velocity sensor; Determine the noise angular velocity power spectrum density at the input end of the sensing element based on the parameter values ​​of the respective equivalent devices and the shape parameters of the magnet; In the case where it is determined that the noise angular velocity power spectrum density at the input end of the sensing element satisfies a first predetermined noise angular velocity power spectrum density condition, determining the noise angular velocity power spectrum density of the MHD angular velocity sensor based on the parameter values ​​of each of the plurality of equivalent components and the turns ratio of the primary winding to the secondary winding; determining a gain of an amplifier when it is determined that the noise angular velocity power spectrum density of the MHD angular velocity sensor satisfies a second predetermined noise angular velocity power spectrum density condition; The MHD angular velocity sensor is manufactured based on the shape data of the upper electrode, the lower electrode, the conductive fluid ring, the magnetic core, the magnet, the primary winding and the secondary winding, the turns ratio, and the gain of the amplifier.

8. The method for manufacturing a low-noise MHD angular velocity sensor according to claim 7, characterized in that: Also includes: When it is determined that the noise angular velocity power spectrum density at the input end of the sensing element does not satisfy a first predetermined noise angular velocity power spectrum density condition, adjusting the shape data of each of the upper electrode, the lower electrode, the conductive fluid ring, the magnetic core, the magnet, the primary winding, and the secondary winding; The noise angular velocity power spectrum density at the input end of the sensor element is re-determined based on the adjusted shape data of the upper electrode, the lower electrode, the conductive fluid ring, the magnetic core, the magnet, the primary winding and the secondary winding.

9. The method for manufacturing a low-noise MHD angular velocity sensor according to claim 7, characterized in that: Also includes: When it is determined that the noise angular velocity power spectrum density of the MHD angular velocity sensor does not satisfy a second predetermined noise angular velocity power spectrum density condition, adjusting the shape data of each of the upper electrode, the lower electrode, the conductive fluid ring, the magnetic core, the magnet, the primary winding, and the secondary winding, as well as the turns ratio; The noise angular velocity power spectrum density of the MHD angular velocity sensor is re-determined based on the adjusted shape data of the upper electrode, the lower electrode, the conductive fluid ring, the magnetic core, the magnet, the primary winding, and the secondary winding, as well as the turns ratio.

10. A method for detecting angular velocity, characterized in that: include: Obtain the initial angular velocity detected by the MHD angular velocity sensor; Update the initial angular velocity based on the background noise of the MHD angular velocity sensor to obtain a target angular velocity; The background noise of the MHD angular velocity sensor is determined by using the background noise determination method of a low-noise MHD angular velocity sensor as described in any one of claims 1 to 6.

Images