A method and system for real-time monitoring of fundamental frequency vibration signals of a magnetic levitation rotor

Abstract

The application provides a magnetic suspension rotor fundamental frequency vibration signal real-time monitoring method and system, and belongs to the technical field of magnetic suspension bearings; the method comprises the following steps: collecting an original displacement signal; using an adaptive wave trap to pre-process the displacement signal; selecting an initial voltage signal according to the real-time rotating speed frequency of the magnetic suspension rotor V c , and inputting the pre-processed displacement signal into a phase-locked loop unit; the phase-locked loop unit is used for tracking the fundamental frequency component in the displacement signal which is synchronous with the rotating speed, and outputs an instantaneous frequency value and an instantaneous phase value which are synchronous with the fundamental frequency component, and two reference signals; a synchronous demodulator is configured, and based on the instantaneous frequency value, the instantaneous phase value, the two reference signals and the original displacement signal output by the phase-locked loop unit, the real-time amplitude of the fundamental frequency vibration component is extracted; and a rotor unbalanced vibration state vector including the real-time amplitude of the fundamental frequency vibration component, the real-time instantaneous phase value and the real-time instantaneous frequency value is output.

Description

Technical Field

[0001] This invention relates to the field of magnetic levitation bearing technology, and in particular to a method and system for real-time monitoring of the fundamental frequency vibration signal of a magnetic levitation rotor. Background Technology

[0002] Magnetic levitation bearing technology, with its superior characteristics such as non-contact operation, wear-free operation, high speed, and high precision, has been widely used in high-end equipment fields such as high-speed motors, centrifugal compressors, and flywheel energy storage systems. However, due to manufacturing errors, material inhomogeneity, and assembly tolerances, rotor mass imbalance is unavoidable. When the rotor rotates at high speed, the unbalanced mass generates synchronous centrifugal force, causing rotor vibration, affecting equipment stability and reliability, and in severe cases, even leading to system instability. Therefore, effectively suppressing rotor unbalanced vibration is one of the key technical bottlenecks for the engineering and industrialization of magnetic levitation bearing systems.

[0003] Currently, mainstream vibration control strategies are mainly divided into feedback control and feedforward control for active dynamic balancing. Feedback control directly suppresses vibration displacement by adjusting the levitation force of the magnetic bearing in real time. Although it can ensure system stability, its control force is always fighting against the unbalanced force, resulting in high energy consumption, low efficiency, and the potential to mask the true vibration state. In contrast, active dynamic balancing technology based on the "influence coefficient method" applies an equivalent balancing force or mass counterweight to the rotor by identifying the amplitude and phase of the unbalanced force, thus counteracting the unbalanced excitation at its source. This is considered a more efficient and fundamental solution. However, the performance limit of this method depends entirely on the accuracy and real-time performance of measuring the rotor's unbalanced vibration information, specifically the amplitude and precise phase of the fundamental frequency component synchronized with the rotational speed. Existing methods rely on key phase sensor hardware, which is limited by the delay and interference of fast Fourier transform analysis, resulting in insufficient accuracy and real-time performance under dynamic and highly disturbed conditions.

[0004] Therefore, it is essential to provide a method and system for real-time monitoring of the fundamental frequency vibration signal of a magnetically levitated rotor, which can acquire complete information on rotor unbalanced vibration in real time and with high precision without relying on key phase sensors, thus providing a reliable data foundation for active dynamic balancing control. Summary of the Invention

[0005] In view of this, the present invention proposes a method and system for real-time monitoring of the fundamental frequency vibration signal of a magnetic levitation rotor, which can acquire complete state information of rotor unbalance vibration in real time and with high precision under strong harmonic interference and dynamic speed change conditions without relying on key phase sensors.

[0006] On the one hand, the present invention provides a method for real-time monitoring of the fundamental frequency vibration signal of a magnetically levitated rotor, comprising the following steps: S1: A displacement sensor is installed on the magnetic levitation rotor to collect the raw displacement signal output by the displacement sensor; S2: An adaptive notch filter is used to preprocess the displacement signal to suppress harmonic interference components in the original displacement signal, and the preprocessed displacement signal is obtained. S3: Select the initial voltage signal based on the real-time rotational frequency of the magnetic levitation rotor. V c The preprocessed displacement signals are input into the phase-locked loop unit, which tracks the fundamental frequency component in the displacement signal that is synchronized with the rotational speed, and outputs the instantaneous frequency and instantaneous phase values ​​synchronized with the fundamental frequency component, as well as two reference signals. S4: Configure a synchronous demodulator to demodulate the instantaneous frequency value, instantaneous phase value, two reference signals and the original displacement signal output by the phase-locked loop unit, and extract the real-time amplitude of the fundamental frequency vibration component. S5: Outputs a rotor unbalanced vibration state vector including the real-time amplitude, real-time instantaneous phase, and real-time instantaneous frequency of the fundamental frequency vibration component.

[0007] Based on the above technical solutions, preferably, step S2 involves the adaptive notch filter adopting a second-order IIR structure, and the center frequency of the adaptive notch filter being configured to be twice the instantaneous frequency value output by the phase-locked loop unit.

[0008] Preferably, the phase-locked loop unit in step S3 includes a phase detector, a loop filter, and a voltage-controlled oscillator (VCO). The input terminal of the phase detector is connected to the output terminal of the adaptive filter, the output terminal of the phase detector is connected to the input terminal of the loop filter, and the output terminal of the loop filter is connected to the input terminal of the VCO. The output terminal of the VCO is connected to the feedback input terminal of the phase detector and the input terminal of the synchronous demodulator, respectively. The phase detector outputs a phase error signal to the loop filter based on the preprocessed displacement signal from the adaptive notch filter and the feedback signal from the voltage-controlled oscillator. The loop filter receives the phase error signal and outputs a control voltage signal. After receiving the control voltage signal, the voltage-controlled oscillator outputs an instantaneous frequency value and an instantaneous phase value synchronized with the fundamental frequency component, and simultaneously outputs two reference signals. The instantaneous frequency value, instantaneous phase value, and two reference signals serve as the input signal for the synchronous demodulator and the feedback signal for the phase detector.

[0009] More preferably, the initial voltage signal is selected based on the real-time rotational speed frequency of the magnetically levitated rotor. V c This sets the center frequency of the voltage-controlled oscillator to be ω c The real-time rotational speed frequency of the magnetic levitation rotor is ω s The difference between the real-time rotational speed frequency of the magnetic levitation rotor and the center frequency of the voltage-controlled oscillator is obtained and divided by the gain coefficient of the voltage-controlled oscillator.K Obtained.

[0010] More preferably, the transfer function of the voltage-controlled oscillator is: H ( s )= K / s , s For the Laplace operator, the gain coefficient of the voltage-controlled oscillator. K Satisfy the following relationship , and These are the maximum rotor speed frequency and the minimum rotor speed frequency, respectively.

[0011] More preferably, the phase detector employs multiplication phase detection, which receives the preprocessed displacement signal and the quadrature reference signal fed back by the voltage-controlled oscillator, and outputs a phase error signal through multiplication.

[0012] More preferably, the loop filter adopts a proportional-integral controller to filter the phase error signal output by the phase detector, and the transfer function of the loop filter is... G ( s )= K p + K i / s , K p and K i These are the proportional coefficient and the integral coefficient, respectively.

[0013] More preferably, step S4 involves setting the instantaneous frequency value output by the phase-locked loop unit to be... Instantaneous phase value The two reference signals include the in-phase reference signal. and quadrature reference signals The original displacement signal is , and Let n(t) be the frequency and phase of the original displacement signal, and n(t) be the interference signal in the original displacement signal. Multiply the in-phase reference signal by the original displacement signal to obtain the in-phase channel. Multiplying the orthogonal reference signal with the original displacement signal yields the orthogonal path. The signals from the in-phase and positive-mode channels are fed into a filter that only allows DC components to enter, eliminating harmonic components above the second harmonic level, thus obtaining the filtered in-phase DC component. and orthogonal DC components Phase difference ,amplitude .

[0014] More preferably, step S5 involves, when the rotor speed is stable, calculating the composite amplitude. A x Instantaneous frequency value and instantaneous phase value This constitutes the rotor unbalanced vibration state vector; when the rotor speed changes, it is represented by... As the instantaneous phase value, it is related to the amplitude. A x and instantaneous frequency value The rotor unbalanced vibration state vector is synthesized and output to the active dynamic balancing controller.

[0015] On the other hand, the present invention provides a real-time monitoring system for the fundamental frequency vibration signal of a magnetic levitation rotor, used to implement the above-mentioned method, including: The raw displacement signal acquisition unit is arranged on the magnetic levitation rotor to acquire and output the raw displacement signal; The preprocessing unit is connected to the original displacement signal acquisition unit and is used to suppress harmonic interference components in the original displacement signal to obtain the preprocessed displacement signal. The phase-locked processing unit is connected to the preprocessing unit and is used to receive the preprocessed displacement signal, track the rotational speed synchronization fundamental frequency component in the displacement signal, obtain the instantaneous frequency value and instantaneous phase value synchronized with the fundamental frequency component, and provide two reference signals. The synchronous demodulator unit is connected to the phase-locked loop processing unit and the original displacement signal acquisition unit. It is used to demodulate the instantaneous frequency value, instantaneous phase value, two reference signals and the original displacement signal output by the phase-locked loop unit, and extract the real-time amplitude of the fundamental frequency vibration component. The output unit integrates the real-time amplitude, real-time instantaneous phase, and real-time instantaneous frequency of the fundamental frequency vibration component, constructs the rotor unbalanced vibration state vector, and outputs it to the active dynamic balancing controller.

[0016] The present invention provides a method and system for real-time monitoring of the fundamental frequency vibration signal of a magnetically levitated rotor, which has the following advantages compared with the prior art: 1. High precision and high real-time performance: Through the close integration of closed-loop tracking and synchronous demodulation of phase-locked loop, millisecond-level delay tracking of rotor fundamental frequency vibration components is achieved, overcoming the inherent delay and spectral leakage problems of the FFT method. The amplitude and phase measurement accuracy is much higher than that of traditional methods, making it particularly suitable for high-speed, variable-speed rotor systems.

[0017] 2. Strong robustness: The adaptive notch filter and phase-locked loop constitute a dual anti-interference mechanism. The adaptive notch filter suppresses strong harmonics in advance, and the phase-locked loop itself has good narrowband tracking and noise suppression characteristics, which enables the system to reliably and accurately extract the target signal in industrial environments with poor signal-to-noise ratio and strong harmonic interference.

[0018] 3. No additional key phase sensor is required. All vibration state information can be extracted solely by the displacement sensor signal inherent in the magnetic levitation system. This simplifies the system structure, reduces hardware costs and installation complexity, and improves the system's integration and reliability.

[0019] 4. The loop filter parameters can be adaptively adjusted according to the rotor's dynamic process, balancing dynamic tracking speed and steady-state accuracy. This intelligent adjustment mechanism ensures stable tracking of the system under severe operating conditions such as crossing critical speeds, preventing loss of lock-up and broadening the application range. Attached Figure Description

[0020] 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, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart of a method and system for real-time monitoring of the fundamental frequency vibration signal of a magnetic levitation rotor according to the present invention. Figure 2 This is a schematic diagram of the mathematical structure of the phase-locked loop unit of the real-time monitoring method and system for the fundamental frequency vibration signal of a magnetic levitation rotor according to the present invention. Figure 3 This is a schematic diagram of the adaptive loop filter parameter adjustment logic of a real-time monitoring method and system for fundamental frequency vibration signal of a magnetic levitation rotor according to the present invention. Figure 4 This is a simulation example of the method and system for real-time monitoring of the fundamental frequency vibration signal of a magnetic levitation rotor according to the present invention, showing the tracking effect of the output vibration amplitude under the absence of strong harmonic interference. Figure 5 This is a simulation example of the phase tracking effect of a method and system for real-time monitoring of the fundamental frequency vibration signal of a magnetic levitation rotor according to the present invention. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] Existing active dynamic balancing technology for magnetic levitation bearings relies on key phase sensor hardware or is limited by delays and interference in Fast Fourier Transform (FFT) analysis, resulting in insufficient accuracy and real-time performance under dynamic and highly disturbed operating conditions.

[0024] In view of this, on the one hand, such as Figure 1 As shown, a method for real-time monitoring of the fundamental frequency vibration signal of a magnetic levitation rotor includes the following steps: S1: A displacement sensor is installed on the magnetic levitation rotor to collect the raw displacement signal output by the displacement sensor.

[0025] S2: An adaptive notch filter is used to preprocess the displacement signal to suppress harmonic interference components in the original displacement signal, resulting in a preprocessed displacement signal.

[0026] Step S2 involves an adaptive notch filter employing a second-order IIR structure. The center frequency of the adaptive notch filter is configured to be twice the instantaneous frequency value output by the phase-locked loop unit, suppressing the dominant second harmonic interference generated by the electromagnetic nonlinearity of the magnetic levitation bearing system. The transfer function of the adaptive notch filter is generally expressed as... ,in α For the center frequency parameter of the adaptive notch filter, r The parameters for controlling the size of the suppression bandwidth, To control the suppression bandwidth and phase frequency characteristics, , f s The system sampling frequency, f h The center frequency of the notch filter is configured as the instantaneous frequency output in real time by the phase-locked loop unit in this embodiment. f inst To set dynamically, f h = f inst . Figure 1 The 1X in the text refers to the baseband frequency.

[0027] S3: Select the initial voltage signal based on the real-time rotational frequency of the magnetic levitation rotor. V cThe preprocessed displacement signal is input into the phase-locked loop unit, which tracks the fundamental frequency component in the displacement signal that is synchronized with the rotational speed, and outputs the instantaneous frequency value and instantaneous phase value synchronized with the fundamental frequency component, as well as two reference signals.

[0028] The initial voltage signal is selected based on the real-time rotational frequency of the magnetically levitated rotor. V c This sets the center frequency of the voltage-controlled oscillator to be ω c The real-time rotational speed frequency of the magnetic levitation rotor is ω s The difference between the real-time rotational speed frequency of the magnetic levitation rotor and the center frequency of the voltage-controlled oscillator is obtained and divided by the gain coefficient of the voltage-controlled oscillator. K What was obtained: , .

[0029] like Figure 1 and Figure 2 As shown in the figure, the phase-locked loop unit is a closed-loop system. θi and θ0 represent the input phase and output phase, respectively, corresponding to the phase of the external input signal to be tracked and the phase generated by the phase-locked loop unit. K d This represents the gain of a phase detector that converts the phase difference between the input and output phases into a voltage signal.

[0030] The phase-locked loop unit includes a phase detector, a loop filter, and a voltage-controlled oscillator (VCO). The input of the phase detector is connected to the output of the adaptive filter, the output of the phase detector is connected to the input of the loop filter, and the output of the loop filter is connected to the input of the VCO. The output of the VCO is connected to the feedback input of the phase detector and the input of the synchronous demodulator. The phase detector outputs a phase error signal to the loop filter based on the preprocessed displacement signal from the adaptive notch filter and the feedback signal from the voltage-controlled oscillator. The loop filter receives the phase error signal and outputs a control voltage signal. After receiving the control voltage signal, the voltage-controlled oscillator outputs an instantaneous frequency value and an instantaneous phase value synchronized with the fundamental frequency component, and simultaneously outputs two reference signals. The instantaneous frequency value, instantaneous phase value, and two reference signals serve as the input signal for the synchronous demodulator and the feedback signal for the phase detector.

[0031] To achieve accurate tracking of rotor vibration by the digital phase-locked loop (PLL), its dynamic performance must match the rotor's inherent dynamic characteristics. For a second-order PLL unit, the bandwidth... The natural frequency of a second-order phase-locked loop unit Damping ratio , K dThis represents the gain coefficient of the phase detector. K p This is the scaling factor of the loop filter. K i The integral coefficients of the loop filter are used to dynamically adjust the bandwidth by dynamically adjusting the proportional and integral coefficients of the loop filter.

[0032] like Figure 3 As shown, the phase detector employs multiplication phase detection. It receives the preprocessed displacement signal and the quadrature reference signal fed back from the voltage-controlled oscillator, and outputs a phase error signal through multiplication. The loop filter uses a proportional-integral controller to filter the phase error signal output by the phase detector. The transfer function of the loop filter is... G ( s )= K p + K i / s When the rotor is in a dynamic process of acceleration or deceleration, the frequency difference Δf in the corresponding diagram is greater than f0, and increases. K p and K i To broaden the loop bandwidth and improve tracking speed and capability; when the rotor is in a stable state, the corresponding frequency difference Δf in the diagram is less than f0, thus reducing... K p and K i This narrows the loop bandwidth, increases noise suppression capability, and improves the accuracy and stability of the output signal; the signal processed by the phase detector is input into the loop filter for filtering, and finally the control voltage signal is obtained.

[0033] For an alternating current signal, the rate of change of its phase is its frequency; therefore, the phase of the voltage-controlled oscillator output signal... ,in As the output phase, the voltage-controlled oscillator can be understood as having a control voltage as its input. V c For a system with an output phase surplus, the voltage-controlled oscillator is an ideal integrator with the following transfer function: H ( s )= K / s , s For the Laplace operator, the gain coefficient of the voltage-controlled oscillator. K Satisfy the following relationship , and These are the maximum and minimum rotor speed frequencies, respectively. When a phase difference exists, the voltage-controlled oscillator begins integration to bring the phase of the output signal up to the phase of the input signal.

[0034] S4: Configure a synchronous demodulator to demodulate the instantaneous frequency value, instantaneous phase value, two reference signals and the original displacement signal output by the phase-locked loop unit, and extract the real-time amplitude of the fundamental frequency vibration component.

[0035] Step S4 involves setting the instantaneous frequency output of the phase-locked loop unit to be [value]. Instantaneous phase value The two reference signals include the in-phase reference signal. and quadrature reference signals The original displacement signal is , and Let n(t) be the frequency and phase of the original displacement signal, and n(t) be the interference signal in the original displacement signal. Multiply the in-phase reference signal by the original displacement signal to obtain the in-phase channel. Multiplying the orthogonal reference signal with the original displacement signal yields the orthogonal path. The signals from the in-phase and positive-mode channels are fed into a filter that only allows DC components to enter, eliminating harmonic components above the second harmonic level, thus obtaining the filtered in-phase DC component. and orthogonal DC components Phase difference ,amplitude .

[0036] As can be seen, both the in-phase channel and the positive-path channel contain DC components, high-frequency second harmonic components, and other frequency interference signals. Now, by passing the signals from the in-phase channel and the positive-path channel into a low-pass filter that only allows DC components to enter, the high-frequency second harmonic components can be completely attenuated. At the same time, after other frequency interference signals are multiplied with the reference signal, their spectrum will also shift, and their DC components will be 0 or very small, which can also be effectively suppressed.

[0037] S5: Outputs a rotor unbalanced vibration state vector including the real-time amplitude, real-time instantaneous phase, and real-time instantaneous frequency of the fundamental frequency vibration component.

[0038] Step S5 involves determining the composite amplitude when the rotor speed stabilizes. A x Instantaneous frequency value and instantaneous phase value This constitutes the rotor unbalanced vibration state vector; when the rotor speed changes, it is represented by... As the instantaneous phase value, it is related to the amplitude. A x and instantaneous frequency value The rotor unbalanced vibration state vector is synthesized and output to the active dynamic balancing controller.

[0039] On the other hand, the present invention also provides a real-time monitoring system for the fundamental frequency vibration signal of a magnetic levitation rotor, used to implement the above-mentioned method, comprising: The raw displacement signal acquisition unit is arranged on the magnetic levitation rotor to acquire and output the raw displacement signal; The preprocessing unit, connected to the original displacement signal acquisition unit, is used to suppress harmonic interference components in the original displacement signal to obtain the preprocessed displacement signal. The phase-locked processing unit is connected to the preprocessing unit and is used to receive the preprocessed displacement signal, track the rotational speed synchronization fundamental frequency component in the displacement signal, obtain the instantaneous frequency value and instantaneous phase value synchronized with the fundamental frequency component, and provide two reference signals. The synchronous demodulator unit is connected to the phase-locked loop processing unit and the original displacement signal acquisition unit. It is used to demodulate the instantaneous frequency value, instantaneous phase value, two reference signals and the original displacement signal output by the phase-locked loop unit, and extract the real-time amplitude of the fundamental frequency vibration component. The output unit integrates the real-time amplitude, real-time instantaneous phase, and real-time instantaneous frequency of the fundamental frequency vibration component, constructs the rotor unbalanced vibration state vector, and outputs it to the active dynamic balancing controller. Example: According to the steps of this invention, the real-time monitoring parameters of the magnetic levitation rotor are configured as follows, with harmonic interference concentrated at the second harmonic 2X.

[0040]

[0041] A pure sinusoidal signal with a frequency of 100 Hz and an amplitude of 10 μm was generated to simulate the rotor's fundamental frequency vibration displacement, and Gaussian white noise was superimposed to simulate sensor noise. The phase-locked loop (PLL) was initialized to a center frequency of 100 Hz. A second-order PLL with a damping ratio of 1.0 and a loop bandwidth of 5 Hz was used to process the input signal in real time. The original displacement signal was orthogonally demodulated using the high-precision instantaneous phase signal generated by the PLL through synchronous demodulation technology. Then, the DC component was extracted using a low-pass filter with a cutoff frequency of 2 Hz, and the amplitude and phase of the real-time vibration were calculated. The resulting graph is shown below. Figure 4 , Figure 5As shown, the real-time vibration monitoring method proposed in this invention can achieve rapid and high-precision locking and tracking of the rotor's fundamental frequency vibration component, with a phase tracking error of <±5° and an amplitude extraction error of <3%. It overcomes the inherent defects of traditional FFT methods in terms of real-time performance and adaptability to dynamic processes. Simulation results fully verify the effectiveness, accuracy, and reliability of the technical solution of this invention. The complete vibration state vector output by this invention has high accuracy in amplitude, phase, and frequency, and low delay, providing an ideal feedback signal for a high-performance active dynamic balancing controller, thereby significantly improving the vibration suppression effect.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for real-time monitoring of the fundamental frequency vibration signal of a magnetically levitated rotor, characterized in that, Includes the following steps: S1: A displacement sensor is installed on the magnetic levitation rotor to collect the raw displacement signal output by the displacement sensor; S2: An adaptive notch filter is used to preprocess the displacement signal to suppress harmonic interference components in the original displacement signal, and the preprocessed displacement signal is obtained. S3: Select the initial voltage signal based on the real-time rotational frequency of the magnetic levitation rotor. V c The preprocessed displacement signals are input into the phase-locked loop unit, which tracks the fundamental frequency component in the displacement signal that is synchronized with the rotational speed, and outputs the instantaneous frequency and instantaneous phase values ​​synchronized with the fundamental frequency component, as well as two reference signals. S4: Configure a synchronous demodulator to demodulate the instantaneous frequency value, instantaneous phase value, two reference signals and the original displacement signal output by the phase-locked loop unit, and extract the real-time amplitude of the fundamental frequency vibration component. S5: Outputs a rotor unbalanced vibration state vector including the real-time amplitude, real-time instantaneous phase, and real-time instantaneous frequency of the fundamental frequency vibration component.

2. The method for real-time monitoring of the fundamental frequency vibration signal of a magnetically levitated rotor according to claim 1, characterized in that, Step S2 involves the adaptive notch filter employing a second-order IIR structure, with its center frequency configured to be twice the instantaneous frequency value output by the phase-locked loop unit.

3. The method for real-time monitoring of the fundamental frequency vibration signal of a magnetically levitated rotor according to claim 2, characterized in that, The phase-locked loop unit mentioned in step S3 includes a phase detector, a loop filter, and a voltage-controlled oscillator. The input terminal of the phase detector is connected to the output terminal of the adaptive filter, the output terminal of the phase detector is connected to the input terminal of the loop filter, and the output terminal of the loop filter is connected to the input terminal of the voltage-controlled oscillator. The output terminal of the voltage-controlled oscillator is connected to the feedback input terminal of the phase detector and the input terminal of the synchronous demodulator, respectively. The phase detector outputs a phase error signal to the loop filter based on the preprocessed displacement signal from the adaptive notch filter and the feedback signal from the voltage-controlled oscillator. The loop filter receives the phase error signal and outputs a control voltage signal. After receiving the control voltage signal, the voltage-controlled oscillator outputs an instantaneous frequency value and an instantaneous phase value synchronized with the fundamental frequency component, and simultaneously outputs two reference signals. The instantaneous frequency value, instantaneous phase value, and two reference signals serve as the input signal for the synchronous demodulator and the feedback signal for the phase detector.

4. The method for real-time monitoring of the fundamental frequency vibration signal of a magnetically levitated rotor according to claim 3, characterized in that, The initial voltage signal is selected based on the real-time rotational frequency of the magnetic levitation rotor. V c This sets the center frequency of the voltage-controlled oscillator to be ω c The real-time rotational frequency of the magnetic levitation rotor is ω s The difference between the real-time rotational speed frequency of the magnetic levitation rotor and the center frequency of the voltage-controlled oscillator is obtained and divided by the gain coefficient of the voltage-controlled oscillator. K Obtained.

5. The method for real-time monitoring of the fundamental frequency vibration signal of a magnetically levitated rotor according to claim 4, characterized in that, The transfer function of the voltage-controlled oscillator is: H ( s )= K / s , s For the Laplace operator, the gain coefficient of the voltage-controlled oscillator. K Satisfy the following relationship , and These are the maximum rotor speed frequency and the minimum rotor speed frequency, respectively.

6. The method for real-time monitoring of the fundamental frequency vibration signal of a magnetically levitated rotor according to claim 5, characterized in that, The phase detector employs multiplication phase detection, which receives the preprocessed displacement signal and the quadrature reference signal fed back by the voltage-controlled oscillator, and outputs a phase error signal through multiplication.

7. The method for real-time monitoring of the fundamental frequency vibration signal of a magnetically levitated rotor according to claim 6, characterized in that, The loop filter employs a proportional-integral controller to filter the phase error signal output from the phase detector. The transfer function of the loop filter is: G ( s )= K p + K i / s , K p and K i These are the proportional coefficient and the integral coefficient, respectively.

8. The method for real-time monitoring of the fundamental frequency vibration signal of a magnetically levitated rotor according to claim 3, characterized in that, Step S4 involves setting the instantaneous frequency output of the phase-locked loop unit to be [value]. Instantaneous phase value The two reference signals include the in-phase reference signal. and quadrature reference signals The original displacement signal is , and Let n(t) be the frequency and phase of the original displacement signal, and n(t) be the interference signal in the original displacement signal. Multiply the in-phase reference signal with the original displacement signal to obtain the in-phase channel. Multiply the quadrature reference signal with the original displacement signal to obtain the quadrature channel. Feed the signals from the in-phase channel and the quadrature channel into a filter that only allows DC components to enter, eliminating harmonic components above the second harmonic, to obtain the filtered in-phase DC component. I and orthogonal DC components Q The phase difference is obtained from the in-phase DC component and the quadrature DC component. and amplitude A x .

9. The method for real-time monitoring of the fundamental frequency vibration signal of a magnetically levitated rotor according to claim 8, characterized in that, Step S5 involves determining the composite amplitude when the rotor speed stabilizes. A x Instantaneous frequency value and instantaneous phase value This constitutes the rotor unbalanced vibration state vector; when the rotor speed changes, it is represented by... As the instantaneous phase value, it is related to the amplitude. A x and instantaneous frequency value The rotor unbalanced vibration state vector is synthesized and output to the active dynamic balancing controller.

10. A real-time monitoring system for the fundamental frequency vibration signal of a magnetically levitated rotor, used to implement the method as described in any one of claims 1-9. Its characteristic features include: The raw displacement signal acquisition unit is arranged on the magnetic levitation rotor to acquire and output the raw displacement signal; The preprocessing unit, connected to the original displacement signal acquisition unit, is used to suppress harmonic interference components in the original displacement signal to obtain the preprocessed displacement signal. The phase-locked processing unit is connected to the preprocessing unit and is used to receive the preprocessed displacement signal, track the rotational speed synchronization fundamental frequency component in the displacement signal, obtain the instantaneous frequency value and instantaneous phase value synchronized with the fundamental frequency component, and provide two reference signals. The synchronous demodulator unit is connected to the phase-locked loop processing unit and the original displacement signal acquisition unit. It is used to demodulate the instantaneous frequency value, instantaneous phase value, two reference signals and the original displacement signal output by the phase-locked loop unit, and extract the real-time amplitude of the fundamental frequency vibration component. The output unit integrates the real-time amplitude, real-time instantaneous phase, and real-time instantaneous frequency of the fundamental frequency vibration component, constructs the rotor unbalanced vibration state vector, and outputs it to the active dynamic balancing controller.

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