A method and apparatus for measuring the transfer function of a magnetic bearing inductance sensor

Abstract

The application relates to a kind of magnetic suspension bearing inductance sensor transfer function measurement method and device, the present application is applied to magnetic suspension bearing inductance sensor, comprising: configuration is used to form frequency scanning sine wave function generator and multiplier;The sine signal generation module of the magnetic suspension bearing inductance sensor and function generator are connected the multiplier, the multiplier is multiplied to obtain measurement amplitude modulation wave that function generator and sine signal generation module output;The output of multiplier is connected the signal processing circuit of the magnetic suspension bearing inductance sensor;The signal processing circuit processes measurement amplitude modulation wave;The relationship of the signal processing circuit output and record and function generator frequency is detected, and the relationship of the gain of magnetic suspension bearing inductance sensor and frequency is obtained.The present application can avoid the inhibition of phase-sensitive detection circuit to signal, realize the transfer function measurement of magnetic suspension bearing inductance sensor frequency sweep type.

Description

Technical Field

[0001] This invention relates to the field of magnetic levitation bearing inductance sensor transfer function measurement technology, and in particular to a method and apparatus for measuring the transfer function of magnetic levitation bearing inductance sensor. Background Technology

[0002] The statements in this section are merely background information relating to this disclosure and do not necessarily constitute prior art.

[0003] Magnetic levitation bearing technology is widely used in high-speed motors, precision instruments, aerospace, and other fields due to its advantages such as non-contact operation, wear-free operation, and low energy consumption. In magnetic levitation systems, inductive sensors, as key displacement detection elements, directly affect the control accuracy and stability of the system due to their dynamic characteristics. Therefore, research on the transfer function measurement method of magnetic levitation bearing inductive sensors has significant theoretical and engineering implications. Current research on inductive sensors mostly focuses on their static characteristics, with limited research on dynamic response measurement methods, making it difficult to meet the high dynamic performance requirements of high-speed magnetic levitation systems. If only static accuracy (i.e., measurement accuracy when the rotor is stationary) is considered, the bandwidth limitation of the magnetic levitation bearing inductive sensor will become apparent once the rotor begins high-speed rotation. When the magnetic levitation bearing inductive sensor cannot keep up with the rapid displacement changes of the rotor, the output signal will experience amplitude attenuation and phase lag. This can lead to the controller issuing incorrect commands; for example, the controller might still be executing an upward command when the rotor has already shifted downwards, causing severe self-excited oscillations and directly leading to system instability. Therefore, measuring the transfer function (especially the frequency response characteristics) of the magnetic levitation bearing inductor sensor, determining its cutoff frequency and resonant point, and ensuring that the magnetic levitation bearing inductor sensor can provide real-time, distortion-free displacement feedback throughout the full speed range is of great significance.

[0004] Currently, experimental methods for testing the transfer function of sensors mainly include the frequency response method, the step response method, and the impulse response method. Among them, the frequency response method can measure the transfer function of inductive sensors more accurately; however, the frequency response method requires inputting a sinusoidal signal with constant amplitude and continuously varying frequency over time into the system. After the system reaches steady state, the amplitude of the output signal is measured, the amplitude gain at each frequency point is calculated, and the amplitude gain versus frequency relationship is plotted. When measuring the response of a magnetic levitation bearing inductive sensor, if the frequency of the test sinusoidal signal is inconsistent with the carrier frequency, the test sinusoidal signal will be suppressed by the phase-sensitive detection circuit in the magnetic levitation bearing inductive sensor. Especially when the frequency of the test sinusoidal signal is an even harmonic of the carrier frequency, the output is almost zero. This results in a small output signal amplitude B during the frequency sweep measurement of the dynamic response, making it impossible to obtain an effective amplitude gain and frequency curve. Summary of the Invention

[0005] To solve the above-mentioned technical problems, or at least partially solve them, the present invention provides a method and apparatus for measuring the transfer function of a magnetic levitation bearing inductance sensor.

[0006] This invention provides a method for measuring the transfer function of an inductance sensor in a magnetic levitation bearing, applicable to such inductance sensors, comprising: Configure a function generator and multiplier to form a frequency-scanning sine wave; The sine wave signal generation module and function generator of the magnetic levitation bearing inductance sensor are connected to the multiplier. The multiplier multiplies the outputs of the function generator and the sine wave signal generation module to obtain the measured amplitude-modulated wave. Connect the output of the multiplier to the signal processing circuit of the magnetic levitation bearing inductance sensor. The signal processing circuit processes the measured amplitude-modulated wave; The relationship between the gain and frequency of the magnetic levitation bearing inductor sensor is obtained by detecting the output of the signal processing circuit and recording its relationship with the frequency of the function generator.

[0007] Furthermore, the magnetic levitation bearing inductive sensor includes: a sensor body coil disposed outside the rotor core, the sensor body coil being connected in series with a sine wave signal generation module and a constant current drive circuit, and the sensor body coil being connected to a signal processing circuit. The sensor body coil consists of two sets of coils connected in series. The sinusoidal signal generation module, in conjunction with the constant current drive circuit, injects a carrier current of a set frequency into the sensor body coil; The signal processing circuit includes: a preamplifier circuit, a phase-sensitive detector circuit connected to the preamplifier circuit, and a signal conditioning circuit connected to the phase-sensitive detector circuit. When the rotor core moves inside the coil, it changes the magnetic reluctance of the magnetic circuit of the sensor body coil, and the amplitude of the amplitude-modulated wave output by the sensor body coil changes. The amplitude-modulated wave is composed of a fixed frequency carrier signal and an amplitude change signal that reflects the rotor position. The frequency of the amplitude-modulated wave is the carrier frequency, and the shape of the amplitude-modulated wave envelope contains the rotor position information. The signal processing circuit extracts the position information from the amplitude-modulated wave.

[0008] Furthermore, the frequency-scanning sine wave generated by the function generator is represented as: , in, The amplitude of the frequency-scanning sine wave; The frequency of the frequency sweep sine wave is the angular frequency.

[0009] Furthermore, the angular frequency of a sine wave It changes linearly with time, and is expressed as: , Let be the initial value of the angular frequency of the frequency-scanning sine wave. Let be the final angular frequency of the frequency-scanning sine wave, T be the frequency scan duration, and t be the time point. The final angular frequency of the frequency-scanning sine wave satisfies: , This is the cutoff angular frequency of the low-pass filter in the phase-sensitive detector circuit. ω is the angular frequency of the carrier signal.

[0010] Furthermore, the angular frequency of a sine wave Represented as: , Let be the initial value of the angular frequency of the frequency-scanning sine wave. Let be the final angular frequency of the frequency-scanning sine wave, T be the frequency scan duration, and t be the time point. The final angular frequency of the frequency-scanning sine wave satisfies: , This is the cutoff angular frequency of the low-pass filter in the phase-sensitive detector circuit. ω is the angular frequency of the carrier signal.

[0011] Furthermore, during the generation of the amplitude-modulated wave, the sinusoidal signal generation module of the magnetic levitation bearing inductor sensor generates a sinusoidal carrier with constant amplitude and frequency according to the operating requirements of the magnetic levitation bearing inductor sensor. The frequency of the sinusoidal carrier is much greater than the maximum frequency of the frequency scanning sine wave.

[0012] Furthermore, the phase-sensitive detection circuit is a combination of a multiplier and a low-pass filter, with the low-pass filter having a cutoff angular frequency of... satisfy: ; The multiplier in the phase-sensitive detector circuit multiplies the measured amplitude-modulated wave with the reference signal to obtain: ; This represents the final angular frequency of the frequency-scanning sine wave. These are the amplitudes of the frequency-scanning sine wave and the carrier signal, respectively. To determine the angular frequency of a sine wave, The angular frequency of the carrier signal; The measured amplitude-modulated wave output from the low-pass filter of the phase-sensitive detector circuit is: .

[0013] Furthermore, The spectrum is located in ,because , It passes entirely through the low-pass filter. The center angular frequency is The modulation signal, , The spectrum is far from the baseband and is completely suppressed by the low-pass filter.

[0014] Furthermore, considering the gain and zero-point offset Then the final output of the signal processing circuit is: .

[0015] Secondly, the present invention provides a device for measuring the transfer function of a magnetic levitation bearing inductance sensor, comprising: at least one processing unit, wherein the processing unit is connected to a storage unit and a measurement execution unit via a bus unit, the storage unit storing a computer program that can run on a processor, characterized in that the measurement execution unit includes a function generator and a multiplier, the measurement execution unit and the processing unit are connected to a magnetic levitation bearing inductance sensor, and the processing unit implements the method for measuring the transfer function of the magnetic levitation bearing inductance sensor by running the computer program stored in the storage unit.

[0016] The technical solutions provided in the embodiments of the present invention have the following advantages compared with the prior art: This invention inputs a frequency-scanning sinusoidal signal generated by a function generator and a carrier signal generated by a sinusoidal signal generation module of a magnetic levitation bearing inductor sensor into a multiplier. Through multiplication, a measurement amplitude-modulated wave is generated. The envelope of the measurement amplitude-modulated wave is the frequency-scanning sinusoidal signal. A phase-sensitive detector uses the multiplier to shift the signal spectrum and then passes it through a subsequent low-pass filter to remove high-frequency carrier components, retaining only the low-frequency envelope signal reflecting the frequency sweep characteristics. After smoothing and zero-biasing the low-frequency envelope, an effective frequency-dependent amplitude response can be obtained, avoiding signal suppression by the phase-sensitive detector circuit. This effectively obtains the transfer function of the magnetic levitation bearing inductor sensor and reveals its dynamic response. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of a magnetic levitation bearing inductor sensor provided in an embodiment of the present invention; Figure 2A schematic diagram of a circuit for measuring the transfer function of an inductance sensor for a magnetic levitation bearing, provided in an embodiment of the present invention; Figure 3 A schematic diagram of the carrier wave, frequency scanning sine wave, amplitude modulation wave measurement, and signal waveforms output by the signal processing circuit provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of a magnetic levitation bearing inductance sensor transfer function measurement device provided in an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0022] Example 1 This invention provides a method for measuring the transfer function of an inductance sensor for a magnetic levitation bearing, applicable to inductance sensors for magnetic levitation bearings.

[0023] like Figure 1As shown, the magnetic levitation bearing inductive sensor includes two series-connected sensor body coils disposed outside the rotor. The sensor body coils are connected to an excitation circuit, which includes a sine wave signal generation module and a constant current drive circuit. The middle lead of the sensor body coils is connected to a signal processing circuit. The magnetic levitation bearing inductive sensor converts the rotor's mechanical displacement into a change in inductance and detects the displacement using the signal change caused by the inductance change. Its operation follows the process of excitation, induction, and demodulation. During excitation, the sine wave signal generation module, in conjunction with the constant current drive circuit, injects a carrier current of a set frequency into the sensor body coil of the magnetic levitation bearing inductive sensor. The sensor body consists of two sets of series-connected coils. When the rotor core moves inside the coils, it changes the magnetic reluctance of the magnetic circuit, causing a change in the amplitude of the sine wave output from the middle lead of the two sets of coils. This sine wave consists of two parts: a fixed-frequency carrier signal and an amplitude-modulated wave composed of a signal reflecting the rotor's position change. The frequency of the amplitude-modulated wave is still the carrier frequency, but the shape of its envelope contains information about the rotor's position trajectory. If the rotor core moves upward, the inductance L1 of the upper coil increases, and the inductance L2 of the lower coil decreases, forming a differential. This differential structure not only improves sensitivity but also effectively compensates for temperature drift and nonlinear errors. After the amplitude-modulated wave is amplified by the preamplifier, it is input to the phase-sensitive detector circuit. The phase-sensitive detector circuit receives the reference signal provided by the sine wave generation module. Using the reference signal that is in phase and frequency with the carrier wave, the amplitude-modulated wave is rectified to filter out the carrier component, leaving an amplitude change signal that reflects the rotor position. This amplitude change signal is then amplified by the signal conditioning circuit and the zero-point bias signal is adjusted before outputting the required voltage signal for use by the subsequent control circuit.

[0024] To avoid the phase-sensitive detection circuit in a magnetic levitation bearing inductance sensor suppressing the gain of signals deviating from the carrier frequency, this invention provides a method for measuring the transfer function of a magnetic levitation bearing inductance sensor, comprising: First, configure the function generator and multiplier to form a frequency-scanning sine wave.

[0025] The frequency-scanning sine wave generated by the function generator is represented as follows: , in, For a frequency-scanning sine wave with a fixed amplitude, The frequency of the frequency sweep sine wave is the angular frequency.

[0026] In one example, It changes linearly with time, and is expressed as: , Let be the initial value of the angular frequency of the frequency-scanning sine wave. T represents the final angular frequency of the frequency-scanning sine wave, T represents the frequency scan duration, and t represents the time point.

[0027] In another example, the frequency sweeps the angular frequency of the sine wave. Represented as: , Let be the initial value of the angular frequency of the frequency-scanning sine wave. T represents the final angular frequency of the frequency-scanning sine wave, T represents the frequency scan duration, and t represents the time point.

[0028] The final angular frequency of the frequency-scanning sine wave satisfies: , This is the cutoff angular frequency of the low-pass filter in the phase-sensitive detector circuit. ω is the angular frequency of the carrier signal.

[0029] The function generator produces a frequency sweep sine wave with varying frequency but constant amplitude.

[0030] Then, the sine wave signal generation module and function generator of the magnetic levitation bearing inductance sensor are connected to the multiplier. The multiplier multiplies the outputs of the function generator and the sine wave signal generation module to obtain the measured amplitude-modulated wave. The envelope of the measured amplitude-modulated wave is the frequency-sweep sine wave signal.

[0031] During the process of obtaining the amplitude-modulated wave measurement, the constant current drive circuit of the magnetic levitation bearing inductor sensor does not function, while the sine wave generation module generates a carrier wave according to the operating requirements of the magnetic levitation bearing inductor sensor. That is, the sine wave generation module generates a sine wave carrier signal with constant amplitude and frequency. ,in, The angular frequency of the sinusoidal carrier signal. This represents the amplitude of the sinusoidal carrier signal. The angular frequency of the sinusoidal carrier is also mentioned. Much greater than the maximum angular frequency of the frequency-scanning sine wave .

[0032] Connect the output of the multiplier to the signal processing circuit of the magnetic levitation bearing inductance sensor, such as... Figure 2 As shown, the measured amplitude-modulated wave is amplified by the preamplifier in the signal processing circuit. This amplification changes the amplitude but not the frequency. After amplification, the measured amplitude-modulated wave is input to the phase-sensitive detector circuit. The phase-sensitive detector circuit receives a sinusoidal carrier wave as a reference signal and filters out the carrier signal from the measured amplitude-modulated wave based on the frequency of the reference signal. The output of the phase-sensitive detector circuit is then amplified and adjusted by the signal conditioning circuit, followed by zero-point bias signal adjustment, before being output as a processed voltage signal. The amplitude of the final output voltage signal component reflects the angular frequency of the sine wave being scanned by the signal processing circuit. The gain characteristics at a given point can be measured by sweeping the frequency to obtain the complete frequency response.

[0033] like Figure 3 As shown, the principle of this application is as follows: The frequency scanning sine wave is: The carrier signal is: The multiplier multiplies the frequency scanning sine wave and the carrier signal to obtain the measured amplitude-modulated wave. The phase-sensitive detector reference signal is synchronized with the original carrier wave. .

[0034] The phase-sensitive detector circuit is a combination of a multiplier and a low-pass filter, with the low-pass filter having a cutoff angular frequency of... satisfy: The multiplier in the phase-sensitive detector circuit multiplies the measured amplitude-modulated wave with the reference signal to obtain: ; Will Substituting into the above equation, we get: ; in, The spectrum is located in ,because , It passes through the low-pass filter completely.

[0035] The center angular frequency is The modulation signal, Its spectrum is far from the baseband and is completely suppressed by the low-pass filter.

[0036] Therefore, the measured amplitude-modulated wave output by the low-pass filter of the phase-sensitive detector circuit is: ; Considering gain and zero-point offset as Then the final output of the signal processing circuit is: ; Therefore, after phase-sensitive detection and low-pass filtering, the output is proportional to the frequency sweep sine wave, thus allowing for accurate measurement of the system's response to the frequency sweep sine signal.

[0037] The relationship between the gain and frequency of the magnetic levitation bearing inductor sensor is obtained by detecting the output of the signal processing circuit and recording its relationship with the frequency of the function generator.

[0038] Example 2 like Figure 4As shown, this embodiment of the invention provides a device for measuring the transfer function of a magnetic levitation bearing inductance sensor, comprising: at least one processing unit, the processing unit being connected to a storage unit and a measurement execution unit via a bus unit, the measurement execution unit including a function generator and a multiplier, the measurement execution unit and the processing unit being connected to a magnetic levitation bearing inductance sensor, and the storage unit serving as a computer-readable storage medium for storing software programs, computer-executable programs, and modules, such as the software program, computer-executable program, and module corresponding to the magnetic levitation bearing inductance sensor transfer function measurement method in this embodiment of the invention. The processing unit implements the aforementioned magnetic levitation bearing inductance sensor transfer function measurement method by running the software program, computer-executable program, and module stored in the storage unit.

[0039] Of course, the computer program stored in the memory of the magnetic levitation bearing inductance sensor transfer function measurement device provided in the embodiments of the present invention is not limited to the method operation described above, and can also execute related operations in the magnetic levitation bearing inductance sensor transfer function measurement method provided in any embodiment of the present invention.

[0040] Example 3 This invention provides a computer-readable storage medium storing a computer program for a device for measuring the transfer function of a magnetic levitation bearing inductance sensor. The device is configured with a function generator and a multiplier for generating a frequency-scanning sine wave. The sine wave generation module and the function generator of the magnetic levitation bearing inductance sensor are connected to the multiplier, which multiplies the outputs of the function generator and the sine wave generation module to obtain a measured amplitude-modulated wave. The output of the multiplier is connected to the signal processing circuit of the magnetic levitation bearing inductance sensor. When the computer program is executed, it implements the method for measuring the transfer function of the magnetic levitation bearing inductance sensor, including: The signal processing circuit processes the measured amplitude-modulated wave; The relationship between the gain and frequency of the magnetic levitation bearing inductor sensor is obtained by detecting the output of the signal processing circuit and recording its relationship with the frequency of the function generator.

[0041] In the embodiments provided by this invention, it should be understood that the disclosed structures and methods can be implemented in other ways. For example, the structural embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interfaces, structures, or units, and may be electrical, mechanical, or other forms.

[0042] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0043] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0044] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for measuring the transfer function of an inductance sensor in a magnetic levitation bearing, characterized in that, Inductive sensors used in magnetic levitation bearings include: Configure a function generator and multiplier to form a frequency-scanning sine wave; The sine wave signal generation module and function generator of the magnetic levitation bearing inductance sensor are connected to the multiplier. The multiplier multiplies the outputs of the function generator and the sine wave signal generation module to obtain the measured amplitude-modulated wave. Connect the output of the multiplier to the signal processing circuit of the magnetic levitation bearing inductance sensor. The signal processing circuit processes the measured amplitude-modulated wave; The relationship between the gain and frequency of the magnetic levitation bearing inductor sensor is obtained by detecting the output of the signal processing circuit and recording its relationship with the frequency of the function generator.

2. The method for measuring the transfer function of an inductor sensor in a magnetic levitation bearing according to claim 1, characterized in that, The magnetic levitation bearing inductive sensor includes: a sensor body coil disposed outside the rotor core, the sensor body coil being connected in series with a sine wave signal generation module and a constant current drive circuit, and the sensor body coil being connected to a signal processing circuit. The sensor body coil consists of two sets of coils connected in series. The sinusoidal signal generation module, in conjunction with the constant current drive circuit, injects a carrier current of a set frequency into the sensor body coil; The signal processing circuit includes: a preamplifier circuit, a phase-sensitive detector circuit connected to the preamplifier circuit, and a signal conditioning circuit connected to the phase-sensitive detector circuit. When the rotor core moves inside the coil, it changes the magnetic reluctance of the magnetic circuit of the sensor body coil, and the amplitude of the amplitude-modulated wave output by the sensor body coil changes. The amplitude-modulated wave is composed of a fixed frequency carrier signal and an amplitude change signal that reflects the rotor position. The frequency of the amplitude-modulated wave is the carrier frequency, and the shape of the amplitude-modulated wave envelope contains the rotor position information. The signal processing circuit extracts the position information from the amplitude-modulated wave.

3. The method for measuring the transfer function of a magnetic levitation bearing inductance sensor according to claim 1, characterized in that, The frequency-scanning sine wave generated by the function generator is represented as follows: ， in, The amplitude of the frequency-scanning sine wave; The frequency of the frequency sweep sine wave is the angular frequency.

4. The method for measuring the transfer function of a magnetic levitation bearing inductance sensor according to claim 3, characterized in that, angular frequency of a sine wave It changes linearly with time, and is expressed as: , Let be the initial value of the angular frequency of the frequency-scanning sine wave. Let be the final angular frequency of the frequency-scanning sine wave, T be the frequency scan duration, and t be the time point. The final angular frequency of the frequency-scanning sine wave satisfies: , This is the cutoff angular frequency of the low-pass filter in the phase-sensitive detector circuit. ω is the angular frequency of the carrier signal.

5. The method for measuring the transfer function of a magnetic levitation bearing inductance sensor according to claim 3, characterized in that, angular frequency of a sine wave Represented as: , Let be the initial value of the angular frequency of the frequency-scanning sine wave. Let be the final angular frequency of the frequency-scanning sine wave, T be the frequency scan duration, and t be the time point. The final angular frequency of the frequency-scanning sine wave satisfies: , This is the cutoff angular frequency of the low-pass filter in the phase-sensitive detector circuit. ω is the angular frequency of the carrier signal.

6. The method for measuring the transfer function of an inductor sensor in a magnetic levitation bearing according to claim 1, characterized in that, During the generation of the amplitude-modulated wave, the sinusoidal signal generation module of the magnetic levitation bearing inductor sensor generates a sinusoidal carrier with constant amplitude and frequency according to the requirements of the magnetic levitation bearing inductor sensor during operation. The frequency of the sinusoidal carrier is much greater than the maximum frequency of the frequency scanning sine wave.

7. The method for measuring the transfer function of a magnetic levitation bearing inductance sensor according to claim 1, characterized in that, The phase-sensitive detector circuit is a combination of a multiplier and a low-pass filter, with the low-pass filter having a cutoff angular frequency of... satisfy: ; The multiplier in the phase-sensitive detector circuit multiplies the measured amplitude-modulated wave with the reference signal to obtain: ； This represents the final angular frequency of the frequency-scanning sine wave. These are the amplitudes of the frequency-scanning sine wave and the carrier signal, respectively. To determine the angular frequency of a sine wave, The angular frequency of the carrier signal; The measured amplitude-modulated wave output from the low-pass filter of the phase-sensitive detector circuit is: 。 8. The method for measuring the transfer function of a magnetic levitation bearing inductance sensor according to claim 7, characterized in that, The spectrum is located in ,because , It passes entirely through the low-pass filter. The center angular frequency is The modulation signal, , The spectrum is far from the baseband and is completely suppressed by the low-pass filter.

9. The method for measuring the transfer function of an inductor sensor in a magnetic levitation bearing according to claim 7, characterized in that, Considering gain and zero-point offset Then the final output of the signal processing circuit is: 。 10. A device for measuring the transfer function of a magnetic levitation bearing inductance sensor, comprising: At least one processing unit is provided, wherein the processing unit is connected to a storage unit and a measurement execution unit via a bus unit, the storage unit stores a computer program that can run on a processor, characterized in that the measurement execution unit includes a function generator and a multiplier, the measurement execution unit and the processing unit are connected to a magnetic levitation bearing inductance sensor, and the processing unit implements the magnetic levitation bearing inductance sensor transfer function measurement method as described in any one of claims 1-9 by running the computer program stored in the storage unit.

Images