Self-adaptive overlapped framing and variable window phase measurement method, device and system based on signal state perception

Abstract

The invention discloses a self-adaptive overlapped framing and variable window phase measurement method, device and system based on signal state perception, and belongs to the technical field of digital signal processing and phase measurement. Aiming at the technical problems that a fixed overlapping ratio and a single window function are adopted in an existing phase measurement method, resolution ratios of a time domain and a frequency domain cannot be considered under a time-varying signal, and frequency spectrum leakage and phase jump are easily introduced, the invention provides a joint self-adaptive preprocessing method. The method comprises the following steps: firstly, framing collected signals, and judging whether the signal state is a steady state or an unsteady state according to smoothness detection of absolute value sums of adjacent sampling points; according to the determined signal state, adaptively configuring an overlapping rate between adjacent data frames and window function type parameters, and then, before fast Fourier transform is carried out, introducing a window function coherent gain compensation mechanism to eliminate an amplitude reference error caused by window type switching; and finally calculating the phase difference based on the corrected spectrum result. According to the method, the overlapping framing and window function parameters are adaptively adjusted according to the signal state, the phase measurement continuity is ensured, the phase measurement precision and stability under the multi-frequency signal are improved, and the method has good real-time performance and engineering application value.

Description

Technical Field

[0001] This invention relates to an adaptive overlapping framing and variable window phase measurement method, apparatus, and system based on signal state perception, belonging to the field of automation equipment technology. Background Technology

[0002] Phase information, as one of the core characteristics of a signal, plays a crucial role in modern industry and scientific research. For example, in smart grids, synchronous phase measurement units, by accurately measuring the voltage / current phase difference at each node of the grid, are the foundation for achieving wide-area monitoring, fault location, and system stability control. In industrial equipment condition monitoring, the phase difference between vibration signals is a key indicator for analyzing mechanical faults such as equipment misalignment and imbalance. In the fields of communication and radar, accurate phase demodulation directly determines the demodulation quality of the signal and the accuracy of target positioning.

[0003] Existing phase measurement methods typically rely on Fast Fourier Transform (FFT) to perform frequency domain analysis on signals. The phase difference is obtained by extracting and calculating the phase information from the complex spectral results. In practical engineering applications, to balance spectral resolution and temporal continuity, the acquired time-domain signal is often segmented into frames, with a certain overlap rate introduced between adjacent data frames. Furthermore, before performing the FFT operation, windowing is usually applied to the segmented signal to suppress spectral leakage and improve frequency domain analysis performance.

[0004] Existing technologies commonly employ a fixed overlap rate and a single window function. While this method can achieve relatively stable phase measurement results under steady-state signal conditions, it exposes various problems when faced with signal amplitude abrupt changes, frequency drift, or transient variations in practical engineering scenarios. When the signal is in a steady state, a high overlap rate introduces redundant calculations, increasing the system's processing burden. Conversely, when the signal is in a non-steady-state or transient phase, a low overlap rate may lead to discontinuous or abrupt phase measurements, affecting measurement accuracy and stability. Different window functions exhibit different spectral characteristics in terms of main lobe width and sidelobe suppression. Using a fixed window function makes it difficult to simultaneously meet the requirements of spectral resolution and phase stability in multi-frequency or time-varying signal scenarios. Therefore, how to achieve real-time sensing of signal status without significantly increasing system complexity, and adaptively adjust the frame overlap rate and window function parameters accordingly, while ensuring the continuity and accuracy of phase measurement results, has become a pressing technical problem to be solved in this field. Summary of the Invention

[0005] The main objective of this invention is to overcome the shortcomings of existing phase measurement techniques and provide a method, system, and apparatus for adaptive overlapping framing and variable window phase measurement based on signal state awareness. This invention aims to address the technical problems of traditional methods, which, due to their use of fixed overlap rates and single window functions, cannot achieve both time-domain and frequency-domain resolution and are prone to introducing spectral leakage and phase jumps, as well as the waste of computational resources or insufficient measurement accuracy. Therefore, this invention achieves high-precision, low-latency, and highly continuous real-time phase measurement.

[0006] To achieve the above objectives / to solve the above technical problems, the present invention is implemented using the following technical solution.

[0007] On one hand, the present invention provides an adaptive overlapping framing and variable window phase measurement method based on signal state awareness, comprising: The acquired signal is segmented into frames to obtain a continuous data frame sequence. Feature parameters representing the local stability of the signal are extracted for smoothness detection. Based on the detection results, the current signal state is determined to be either steady-state or non-steady-state. Specifically, extracting the local stability feature parameters includes calculating the smoothness of the sum of the absolute values ​​of adjacent sampling points. The smoothness is obtained by calculating the change in the sum of the absolute values ​​of sampling points between adjacent data frames. This method avoids complex variance or standard deviation calculations, facilitating low-latency detection implementation in hardware such as FPGAs.

[0008] Furthermore, based on the determined signal state, the overlap rate between adjacent data frames and the window function type parameter matching the overlap rate are adaptively configured. The signal state determination logic is as follows: when the change in the sum of the absolute values ​​of the adjacent sampling points is less than a preset threshold, the current signal state is determined to be steady state; when the change is greater than or equal to the preset threshold, the current signal state is determined to be non-steady state.

[0009] Furthermore, the signal data with configured overlap rate and window function type are windowed, and coherent gain compensation of the window function is introduced simultaneously to generate a corrected time-domain data frame. The specific strategy of the adaptive configuration is as follows: when the signal state is steady-state, a low overlap rate and high sidelobe suppression window function (such as the Blackman window) is configured to reduce computational redundancy and improve frequency domain resolution; when the signal state is non-steady-state, a high overlap rate and narrow main lobe window function (such as the Hanning window or rectangular window) is configured to improve time resolution and quickly capture signal changes. The coherent gain compensation of the window function is specifically achieved by normalizing the amplitude of the fast Fourier transform result and introducing a compensation factor corresponding to the current window function to eliminate the amplitude reference error introduced by changes in window function type or parameters, thus ensuring the continuity of measurement results.

[0010] Furthermore, a Fast Fourier Transform (FFT) is performed on the corrected time-domain data frame to obtain a complex sequence in the frequency domain, and the phase difference is calculated.

[0011] In a second aspect, the present invention provides an adaptive overlapping framing and variable window phase measurement device based on signal state awareness, comprising: The signal acquisition and framing processing module is used to acquire the signal to be tested and perform framing processing on the signal to be tested; The detection and state determination module is used to extract feature parameters that characterize the local stability of the signal, perform smoothness detection, and determine whether the signal state is steady or unstable based on the feature parameters. An adaptive configuration module is used to configure the overlap rate and window function type parameters between adjacent data frames according to the signal state; The frequency domain analysis module is used to perform fast Fourier transform on the configured overlap rate and windowed data frames, and to perform window function coherence gain compensation. The phase calculation module is used to perform spectral analysis on the compensated data and calculate the phase difference between multi-channel signals.

[0012] Thirdly, the present invention provides an adaptive overlapping framing and variable window phase measurement system based on signal state awareness, comprising: Memory, used to store computer programs / instructions; A processor for executing the computer program / instructions to implement the steps of the signal state-aware adaptive overlapping framing and variable window phase measurement method.

[0013] Fourthly, the present invention provides a computer-readable storage medium having a computer program / instruction stored thereon, which, when executed by a processor, implements the steps of the above-described adaptive overlapping framing and variable window phase measurement method based on signal state awareness.

[0014] Compared with existing technologies, the beneficial effects achieved by this invention are as follows: By sensing the signal state, this invention effectively suppresses spectral leakage and ensures high accuracy in phase calculation by employing a low overlap rate combined with a high sidelobe suppression window in steady state; in non-steady state, it automatically switches to a high overlap rate combined with a narrow main lobe window, significantly improving the tracking speed and time resolution of abrupt signals. The stability detection method based on the sum of the absolute values ​​of adjacent sampling points proposed in this invention has extremely low computational load, requiring no complex square root or division operations, making it very suitable for pipelined implementation in embedded hardware such as FPGAs. Simultaneously, automatically reducing the overlap rate in steady state effectively reduces the amount of redundant data processing, lowers the overall power consumption and computational load of the system, and possesses excellent real-time performance and engineering applicability. Attached Figure Description

[0015] Figure 1The diagram shown is a flowchart of the calculation method of the present invention; Figure 2 The diagram shows the system module connection of the present invention; Detailed Implementation

[0016] It should be noted that: The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations thereof. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0017] The term "and / or" simply describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. Additionally, the character " / " generally indicates that the preceding and following related objects have an "or" relationship. Example 1

[0018] like Figures 1-2 One embodiment shown provides an adaptive overlapping framing and variable window phase measurement method based on signal state awareness, including: Signal acquisition and framing processing: Assume the discrete-time sequence of the two signals to be measured is... in The first time domain signal discrete points, There are two signals to be tested; Set the base frame length to During the data entry into the buffer, characteristic parameters of local signal stability are extracted synchronously. In this embodiment, the characteristic parameters are defined as the rate of change of intra-frame smoothness. First, the sum of the absolute values ​​of the differences between adjacent sampling points within the frame is calculated, denoted as... : in, The sequence number of the current data frame. Indicates the first [number] in the current frame One sampling point, Indicates the current frame's... One sampling point, This represents the amount of smoothness change in the signal within the current frame. Furthermore, the change in feature parameters between two adjacent frames is calculated. in, For the first Frame smoothness variation For the first The amount of change in frame smoothness; Furthermore, a preset threshold is set. This threshold is set based on the system noise floor, for example, it can be set to 5% of the signal's full-scale dynamic range. like The current signal is determined to be in a steady state. like The current signal is determined to be in a steady state. Furthermore, based on the determination of whether the signal is in a steady-state or non-steady-state condition, the system automatically looks up a table to configure the overlap rate and window function. When the signal is determined to be in a steady-state condition, a lower overlap rate is configured. Furthermore, a window function with high sidelobe suppression capability, such as the Blackman window, is selected; when the signal is determined to be in an unsteady state, a higher overlap rate is configured. And select window functions with narrow main lobes and high temporal resolution, such as Hanning windows or rectangular windows.

[0019] Furthermore, the configured overlap rate and window function are preset and written into memory, and implemented by state machine-like transitions; The framed signal data is windowed using a window function, and a compensation mechanism is further introduced, defining the coherence gain of the window function. for in, For the window function coherence gain The formula for calculating the window function; The window function amplitude compensation factor can be obtained from the window function correlation gain. for Furthermore, the acquired signal is subjected to Fourier transform and window function compensation in the frequency domain to obtain the frequency domain sequence: in, The first time domain signal Discrete sampling points, For the first in the frequency domain One frequency domain point, The imaginary unit, For Fast Fourier Transform, Let be the total number of discrete sampling points. The frequency domain signal of the first signal to be measured. The frequency domain signal of the second signal to be measured. This is the first time-domain signal to be tested. This is the second time-domain signal to be tested; The phase difference is calculated for the corrected signal, and the specific expression is as follows: ; ; in, The argument of the complex signal: It is the arctangent function. This represents the real part of the corresponding signal in the frequency domain. This represents the imaginary part of the corresponding signal in the frequency domain; The phase difference between the two detection signals and the reference signal is calculated using the following expression: ; Example 2

[0020] This embodiment provides an adaptive overlapping framing and variable window phase measurement device based on signal state awareness, including: The signal acquisition and framing module is used to acquire external input signals and convert them into discrete digital signals via ADC quantization. Data is then buffered using a FIFO and internally includes a dual-port RAM and a read / write pointer controller. The write pointer writes data to the buffer at a constant sampling rate; the read pointer controller is connected to the adaptive configuration module and responds to its step control signals, thereby enabling data framing at different overlap rates at the physical storage level. The detection and state determination module employs a hardware pipelined logic design for real-time signal state monitoring. It includes a differential operation unit, an accumulator, and a comparator. While writing data to the buffer, this module simultaneously calculates the absolute difference between adjacent sampling points and accumulates them within a preset window to obtain a smoothness feature value. This feature value is then compared to a preset threshold, and a steady-state determination flag is output in real time. An adaptive configuration module is used to configure the overlap rate and window function type parameters between adjacent data frames according to the signal state. This module serves as the core of system control and is used to establish a mapping relationship between signal state and processing parameters. This module receives the state identifier signal, outputs control signals through state machine logic, and configures the overlap rate and window function type. The frequency domain analysis module performs windowing, FFT transform, and gain correction. Internally, it includes ROM, a multiplier array, and an FFT IP core. The ROM partition stores coefficients for high sidelobe suppression (e.g., Blackman) and narrow main lobe (e.g., Hanning) window functions. This module reads the corresponding coefficients based on the window function index to window the data frame, performs a Fast Fourier Transform, and uses the received coherent gain compensation factor to normalize the amplitude of the transformed spectral data, eliminating the reference error introduced by window switching. The phase calculation module is used to extract phase information. This module receives the corrected complex spectrum sequence, extracts the phase using the CORDIC algorithm, calculates the phase difference between the multi-channel signals, and outputs the calculation result. Example 3

[0021] This embodiment provides an adaptive overlapping framing and variable window phase measurement system based on signal state awareness, including: Memory, used to store computer programs / instructions; A processor is configured to execute the computer program / instructions to implement the steps of the above-described adaptive overlapping framing and variable window phase measurement method based on signal state awareness. Example 4

[0022] This embodiment provides a computer-readable storage medium storing a computer program / instruction thereon. When the computer program / instruction is executed by a processor, it implements the steps of the above-described adaptive overlapping framing and variable window phase measurement method based on signal state awareness.

[0023] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A method for adaptive overlapping framing and variable window phase measurement based on signal state awareness, characterized in that, include: The acquired signal is processed into frames to obtain a continuous data frame sequence. The feature parameters of the signal's local stability are extracted for smoothness detection. Based on the detection results, it is determined whether the current signal is in a steady state or an unstable state. Based on the determined signal state, adaptively configure the overlap rate between adjacent data frames and the window function type parameter that matches the overlap rate; Windowing is applied to signal data with configured overlap rate and window function type, and window function coherent gain compensation is introduced simultaneously to generate corrected time-domain data frames. The corrected time-domain data frame is subjected to Fast Fourier Transform (FFT) to obtain a complex sequence in the frequency domain, and the phase difference is calculated.

2. The adaptive overlapping framing and variable window phase measurement method based on signal state awareness according to claim 1, characterized in that, The extracted local stability feature parameters include the smoothness of the sum of absolute values ​​of adjacent sampling points, which is obtained by calculating the change in the sum of absolute values ​​of sampling points between adjacent data frames.

3. The adaptive overlapping framing and variable window phase measurement method based on signal state awareness according to claim 1, characterized in that, When the change in the sum of the absolute values ​​of adjacent sampling points is less than a preset threshold, the current signal state is determined to be steady state; when the change is greater than or equal to the preset threshold, the current signal state is determined to be unsteady state.

4. The adaptive overlapping framing and variable window phase measurement method based on signal state awareness according to claim 1, characterized in that, When the signal is in a steady state, it is configured as a low overlap rate and high sidelobe suppression window function; when the signal is in a non-steady state, it is configured as a high overlap rate and narrow main lobe window function.

5. The adaptive overlapping framing and variable window phase measurement method based on signal state awareness according to claim 4, characterized in that, The coherent gain compensation of the window function eliminates the amplitude reference error introduced by changes in the window function type or parameters by normalizing the amplitude of the fast Fourier transform result.

6. An adaptive overlapping framing and variable window phase measurement device based on signal state perception, characterized in that, include: The signal acquisition and framing processing module is used to acquire the signal to be tested and perform framing processing on the signal to be tested; The detection and state determination module is used to extract feature parameters that characterize the local stability of the signal, perform smoothness detection, and determine whether the signal state is steady or unstable based on the feature parameters. An adaptive configuration module is used to configure the overlap rate and window function type parameters between adjacent data frames according to the signal state; The frequency domain analysis module is used to perform fast Fourier transform on the configured overlap rate and windowed data frames, and to perform window function coherence gain compensation. The phase calculation module is used to perform spectral analysis on the compensated data and calculate the phase difference between multi-channel signals.

7. An adaptive overlapping framing and variable window phase measurement system based on signal state awareness, characterized in that, include: Memory, used to store computer programs / instructions; A processor for executing the computer program / instructions to implement the steps of the adaptive overlapping framing and variable window phase measurement method based on signal state awareness as described in any one of claims 1-6.

8. A computer-readable storage medium having a computer program / instructions stored thereon, characterized in that, When the computer program / instruction is executed by the processor, it implements the steps of adaptive overlapping framing and variable window phase measurement based on signal state awareness as described in any one of claims 1-6.

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