Vibration frequency estimation system and method based on real-time signal processing

Abstract

The invention provides a vibration frequency estimation system and method based on real-time signal processing, and relates to the technical field of vibration active control, the system comprises a vibration sensor, a bias circuit and a vibration frequency estimation control module, and the method comprises the following steps: collecting a vibration signal based on the vibration sensor, the bias circuit and a signal collection module; the frequency estimation-based module performs frequency estimation based on the vibration signal, and finally outputs two paths of sine wave signals; the two paths of output sine wave signals are sent to the data integration module based on the data transmission module; and carrying out data integration on the two paths of sine wave signals based on a data integration module. According to the method, the problem that the vibration reduction performance is reduced due to insufficient frequency estimation precision in an existing active vibration control system is solved, and the response speed and the control precision of the system are improved.

Description

Technical Field

[0001] This invention relates to the field of active vibration control technology, and in particular to a vibration frequency estimation system and method based on real-time signal processing. Background Technology

[0002] In the field of active vibration control, real-time, high-precision vibration frequency estimation is a core element in ensuring the performance of control systems. Whether it's vibration reduction in mechanical structures, stable operation of precision equipment, or attitude control of spacecraft, accurate identification of the frequency characteristics of the vibration source is crucial to drive actuators to output real-time counteracting control forces to offset vibration energy. If the frequency estimate deviates from the actual vibration frequency, the counteracting control force will fail to effectively offset the vibration, leading to a significant reduction in vibration reduction and even exacerbating the vibration intensity, affecting the stability and reliability of the entire system. Existing frequency estimation methods are based on Fourier transform, converting the vibration signals collected by sensors from the time domain to the frequency domain for analysis and extracting the main frequencies to adjust the control signals for vibration reduction. While these methods can provide effective frequency estimation under certain conditions, their accuracy is often insufficient when the system experiences significant dynamic changes, resulting in vibration reduction performance failing to meet expectations. Therefore, designing frequency estimation methods with fast dynamic response and high accuracy is of significant practical value in engineering applications.

[0003] Therefore, it is essential to design a vibration frequency estimation system and method based on real-time signal processing. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a vibration frequency estimation system and method based on real-time signal processing.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] This invention provides a vibration frequency estimation system based on real-time signal processing, comprising: a vibration sensor, a bias circuit, and a vibration frequency estimation control module. The vibration sensor is disposed at the vibration source, the vibration sensor is connected to the bias circuit, and the bias circuit is connected to the vibration frequency estimation control module. The vibration sensor is used to obtain the vibration signal from the vibration source, the bias circuit is used to provide a stable voltage to the vibration sensor and to preprocess the vibration signal, and the vibration frequency estimation control module is used to estimate and transmit the vibration frequency.

[0007] Preferably, the vibration frequency estimation and control module includes a signal acquisition module, a frequency estimation module, a data transmission module, and a control integration module. The bias circuit is connected to the signal acquisition module, the signal acquisition module is connected to the frequency estimation module, the frequency estimation module is connected to the data transmission module, and the signal acquisition module, the frequency estimation module, and the data transmission module are all connected to the control integration module.

[0008] Preferably, the signal acquisition module, frequency estimation module, data transmission module, and control integration module are integrated into a microcontroller board equipped with a frequency estimation algorithm.

[0009] Preferably, the microcontroller board is an STM32 microcontroller board, the signal acquisition module is the internal ADC module of the STM32 microcontroller board, the data transmission module is the internal DAC module of the STM32 microcontroller board, and the control integration module is the microcontroller of the STM32 microcontroller board.

[0010] Preferably, the STM32 microcontroller board is connected to the bias circuit module via a bipolar power supply to provide 5V bipolar power.

[0011] The present invention also provides a vibration frequency estimation method based on real-time signal processing, applied to the above-mentioned vibration frequency estimation system based on real-time signal processing, comprising:

[0012] Vibration signals are acquired based on vibration sensors, bias circuits, and signal acquisition modules;

[0013] The frequency estimation module estimates the frequency based on the vibration signal and finally outputs two sinusoidal signals.

[0014] The data transmission module sends the two output sine wave signals to the data integration module.

[0015] The data integration module integrates the data of two sine wave signals.

[0016] Preferably, the frequency estimation module performs frequency estimation based on the vibration signal and finally outputs two sine wave signals, specifically:

[0017] The frequency estimation module acquires the vibration signal and performs filtering processing on it;

[0018] After processing, a Hanning window is applied to the filtered vibration signal, and then a fast Fourier transform is performed.

[0019] Frequency estimation of the spectrum output by the Fast Fourier Transform is performed based on the three-point interpolation method to obtain the spectrum value;

[0020] The frequency value is split into an integer part and a fractional part, and redundancy is added;

[0021] The data transmission module converts the two parts into two sinusoidal wave signal outputs.

[0022] Preferably, the two sine wave signals are integrated based on the data integration module, specifically as follows:

[0023] The data integration module receives two sinusoidal signals, extracts and restores their voltage amplitude, eliminates redundant values, and integrates the high and low bits into the true frequency value.

[0024] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0025] This invention provides a vibration frequency estimation system and method based on real-time signal processing. The system includes: a vibration sensor, a bias circuit, and a vibration frequency estimation control module. The vibration sensor is located at the vibration source and connected to the bias circuit. The bias circuit is connected to the vibration frequency estimation control module. The vibration sensor is used to obtain the vibration signal from the vibration source. The bias circuit provides a stable voltage to the vibration sensor and preprocesses the vibration signal, adjusting the signal amplitude to the 0-3.3V range to match the ADC input range of the STM32 board. The vibration frequency estimation control module is used to estimate and transmit the vibration frequency. The method includes: acquiring the vibration signal based on the vibration sensor, bias circuit, and signal acquisition module; performing frequency estimation based on the vibration signal using the frequency estimation module, and finally outputting two sine wave signals; sending the two output sine wave signals to the data integration module using the data transmission module; and integrating the two sine wave signals using the data integration module. This invention prevents data abrupt changes by using a frequency value splitting method of "integer-fractional separation + redundancy superposition." A sinusoidal carrier mechanism based on voltage proportional mapping converts the split frequency values ​​into sinusoidal signals for transmission, improving anti-interference capabilities compared to traditional digital communication. Furthermore, parallel data transmission via dual carrier waves reduces communication load while maintaining accuracy. The dynamic power supply and signal conditioning mechanism of the STM32 board and bias circuit solves the problems of signal attenuation and noise interference in traditional discrete circuits. Simultaneously, the level-matching interface design between the STM32 board and the controller enables efficient data interaction between processors of different architectures. This invention also addresses the problem of reduced vibration reduction performance caused by insufficient frequency estimation accuracy in existing active vibration control systems, improving system response speed and control accuracy. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments 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.

[0027] Figure 1 This is a schematic diagram of the vibration frequency estimation system based on real-time signal processing according to the present invention.

[0028] Figure 2 This is a schematic diagram of the vibration frequency estimation method based on real-time signal processing according to the present invention. Detailed Implementation

[0029] 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, and 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.

[0030] The purpose of this invention is to provide a vibration frequency estimation system and method based on real-time signal processing. By using a frequency value splitting method of "integer-fractional separation + redundant superposition," sudden data changes can be prevented. A sinusoidal carrier mechanism based on voltage proportional mapping converts the split frequency values ​​into sinusoidal signals for transmission, improving anti-interference capabilities compared to traditional digital communication. Furthermore, parallel data transmission via dual carrier waves reduces communication load while maintaining accuracy. The dynamic power supply and signal conditioning mechanism of the STM32 board and bias circuit solves the problems of signal attenuation and noise interference in traditional discrete circuits. Simultaneously, the level-matching interface design between the STM32 board and the controller enables efficient data interaction between processors of different architectures. This invention solves the problem of insufficient frequency estimation accuracy leading to decreased vibration reduction performance in existing active vibration control systems, improving system response speed and control accuracy.

[0031] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] like Figure 1As shown, this invention provides a vibration frequency estimation system based on real-time signal processing, including: a vibration sensor, a bias circuit, and a vibration frequency estimation control module. The vibration sensor is located at the vibration source and connected to the bias circuit. The bias circuit is connected to the vibration frequency estimation control module. The vibration sensor is used to obtain the vibration signal from the vibration source. The bias circuit is used to provide a stable voltage to the vibration sensor and preprocess the vibration signal, adjusting the signal amplitude to the range of 0-3.3V to match the ADC input range of the STM32 board. The vibration frequency estimation control module is used to estimate and transmit the vibration frequency.

[0033] The vibration frequency estimation and control module includes a signal acquisition module, a frequency estimation module, a data transmission module, and a control integration module. The bias circuit is connected to the signal acquisition module, the signal acquisition module is connected to the frequency estimation module, the frequency estimation module is connected to the data transmission module, and the signal acquisition module, the frequency estimation module, and the data transmission module are all connected to the control integration module.

[0034] The signal acquisition module, frequency estimation module, data transmission module, and control integration module are combined into a microcontroller board equipped with a frequency estimation algorithm.

[0035] The microcontroller board is an STM32 microcontroller board, which serves as the core processing unit, responsible for signal acquisition, frequency calculation, and data transmission. It is an STM32F4 series microcontroller board with high-speed floating-point operation capability, supporting real-time signal processing at a main frequency of 168MHz. The signal acquisition module is the internal ADC module of the STM32 microcontroller board, the data transmission module is the internal DAC module of the STM32 microcontroller board, the control integration module is the microcontroller of the STM32 microcontroller board, the frequency estimation module is equipped with an FFT frequency estimation algorithm, and the internal DAC module is equipped with two 12-bit DACs, namely DAC1 and DAC2.

[0036] The microcontroller sends the acquired frequency data to the controller, which receives the frequency data sent by the STM32 board and generates control commands.

[0037] The STM32 microcontroller board is connected to the bias circuit module via a bipolar power supply to provide 5V bipolar power.

[0038] like Figure 2 As shown, the present invention also provides a vibration frequency estimation method based on real-time signal processing, applied to the above-mentioned vibration frequency estimation system based on real-time signal processing, comprising:

[0039] 1. Signal acquisition stage: The STM32 board samples the vibration signal preprocessed by the bias circuit through the internal ADC module. The sampling frequency is set to 2kHz and the number of sampling points is 1024. The sampled data is temporarily stored in the SRAM buffer of the STM32 board.

[0040] 2. FFT Transformation Stage: The STM32 first performs a second-order IIR low-pass filter on the signal, with a cutoff frequency of 80Hz. Then, it performs a Fast Fourier Transform (FFT) on the filtered data, converting the time-domain signal into a frequency-domain spectrum. To reduce spectral leakage, a Hanning window is applied to the time-domain data before the FFT. The window function expression is w(n) = 0.5 - 0.5cos(2πn / N), where n is the sampling point index, and N = 1024. After the transformation, a complex spectrum with 1024 points is obtained, with a frequency resolution of 1.9531Hz.

[0041] 3. Three-point interpolation stage: Peak detection is performed on the spectrum output by the Fast Fourier Transform, locating the spectral line with the largest amplitude index k0 and its left and right adjacent spectral lines k. 0-1 k 0+1 Extract the amplitude value A of the three. -1 A0, A1. The true frequency offset δ = (A0, A1) is calculated using the parabolic interpolation formula. -1 -A1) / [2×(A -1 -2A0+A1)], the final estimated frequency f=(k0+δ)×1.9531Hz.

[0042] 4. Data splitting and transmission stage: The STM32 board splits the estimated frequency f into an integer part and a fractional part. The fractional part is multiplied by 100 and the first two digits are taken. To prevent jumps during data transmission, a redundancy value of about 0.5 is added to both the integer and fractional parts. Then, the integer and fractional parts are converted into voltage values. The two voltage values ​​are modulated into two sine wave signals by the DAC module and sent to the controller.

[0043] 5. Data integration stage: The controller receives two sinusoidal signals, extracts and restores their voltage amplitude, eliminates redundant values, and integrates the high and low bits into the true frequency value, f = high bit + low bit / 100.

[0044] The discrepancies in vibration frequency estimation results essentially stem from the different combinations of hardware system configuration and software algorithm flow. These differences directly affect the accuracy and stability of the estimated values. On the hardware side, a 24-bit high-precision ADC paired with an STM32H7 series processor can replace the original 12-bit ADC STM32 board, ensuring input signal stability. At the algorithm level, a rectangular window function is used before the Fast Fourier Transform, and data transmission uses a single-channel sine wave for time-division multiplexing of the integer and fractional parts, replacing dual-channel parallel transmission. In the controller integration stage, a moving average filter replaces the redundancy elimination algorithm, thus completing the basic frequency estimation function.

[0045] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0046] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A vibration frequency estimation system based on real-time signal processing, characterized by, include: The system includes a vibration sensor, a bias circuit, and a vibration frequency estimation and control module. The vibration sensor is located at the vibration source and connected to the bias circuit. The bias circuit is connected to the vibration frequency estimation and control module. The vibration sensor is used to detect the vibration signal from the vibration source. The bias circuit provides a stable voltage to the vibration sensor and preprocesses the vibration signal. The vibration frequency estimation and control module is used to estimate and transmit the vibration frequency.

2. The system of claim 1, wherein, The vibration frequency estimation and control module includes a signal acquisition module, a frequency estimation module, a data transmission module, and a control integration module. The bias circuit is connected to the signal acquisition module, the signal acquisition module is connected to the frequency estimation module, the frequency estimation module is connected to the data transmission module, and the signal acquisition module, the frequency estimation module, and the data transmission module are all connected to the control integration module.

3. The system of claim 2, wherein, The signal acquisition module, frequency estimation module, data transmission module, and control integration module are combined into a microcontroller board equipped with a frequency estimation algorithm.

4. The system of claim 3, wherein, The microcontroller board is an STM32 microcontroller board, the signal acquisition module is the internal ADC module of the STM32 microcontroller board, the data transmission module is the internal DAC module of the STM32 microcontroller board, and the control integration module is the microcontroller of the STM32 microcontroller board.

5. The system of claim 4, wherein, The STM32 microcontroller board is connected to the bias circuit module via a bipolar power supply to provide 5V bipolar power.

6. A method for estimating vibration frequency based on real-time signal processing, applied to the system for estimating vibration frequency based on real-time signal processing as claimed in any one of claims 1-5, characterized in that, include: Vibration signals are acquired based on vibration sensors, bias circuits, and signal acquisition modules; The frequency estimation module estimates the frequency based on the vibration signal and finally outputs two sinusoidal signals. The data transmission module sends the two output sine wave signals to the data integration module. The data integration module integrates the data of two sine wave signals.

7. The method of claim 6, wherein, The frequency estimation module estimates the frequency based on the vibration signal and ultimately outputs two sinusoidal signals, specifically: The frequency estimation module acquires the vibration signal and performs filtering processing on it; After processing, a Hanning window is applied to the filtered vibration signal, and then a fast Fourier transform is performed. Frequency estimation of the spectrum output by the Fast Fourier Transform is performed based on the three-point interpolation method to obtain the spectrum value; The frequency value is split into an integer part and a fractional part, and redundancy is added; The data transmission module converts the two parts into two sinusoidal wave signal outputs.

8. The method of claim 7, wherein, The two sine wave signals are integrated using the data integration module, specifically as follows: The data integration module receives two sinusoidal signals, extracts and restores their voltage amplitude, eliminates redundant values, and integrates the high and low bits into the true frequency value.

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