Dynamic displacement sensor calibration device based on rotary sine edge turntable

Abstract

The invention discloses a dynamic displacement sensor calibration device based on a rotary sine edge turntable, which relates to the technical field of displacement sensor calibration, and comprises the following steps: driving the sine edge turntable to rotate based on a rotating speed generation device to generate a multi-band standard sine displacement signal; the rotary motion is converted into periodic radial standard sine displacement change through an approximate sine edge structure; according to the measuring range, bandwidth and probe size information of the displacement sensor to be calibrated, the displacement amplitude is adjusted by replacing sine edge turntables with different amplitudes, and the sine displacement frequency is changed by adjusting the rotating speed parameter of the rotating speed generation device; and based on the dynamic sensitivity parameter, fitting an amplitude-frequency characteristic curve by presetting an attenuation threshold and based on a least square method, and calculating the bandwidth of the sensor according to amplitude attenuation. The medium-high-frequency large-amplitude standard sine displacement can be generated, the dynamic sensitivity and bandwidth calibration requirements of the dynamic displacement sensor can be met, and the medium-high-frequency large-amplitude standard sine displacement sensor has the advantages of being wide in measuring range, small in size and low in manufacturing cost.

Description

Technical Field

[0001] The present invention relates to the technical field of displacement sensor calibration, and particularly to a dynamic displacement sensor calibration device based on a rotating sine-edge turntable. Background Art

[0002] In the technical field of displacement sensor calibration, the dynamic characteristic calibration of sensors, such as the dynamic sensitivity calibration of sensors, depends on a high-frequency vibration table, that is, the vibration table is used to provide a sine standard displacement to calibrate the dynamic sensitivity and bandwidth of the displacement sensor. However, there are some problems in the prior art, such as the large volume and high cost of the vibration table, and the smaller the amplitude when the frequency of the standard sine displacement provided is higher. It is difficult for the vibration table to generate a standard sine displacement with a high frequency and a large amplitude, and it cannot meet the calibration requirements of the dynamic sensitivity and bandwidth of medium-high frequency and large amplitude displacement sensors. Therefore, it is urgent to develop a new generation of dynamic displacement sensor dynamic sensitivity and bandwidth calibration devices. Summary of the Invention

[0003] In view of the above existing problems, the present invention is proposed.

[0004] Therefore, the present invention provides a dynamic displacement sensor calibration device based on a rotating sine-edge turntable, which solves the problem of generating a high-frequency and large-amplitude standard displacement by a traditional vibration table, and realizes the accurate calibration of the medium-high frequency dynamic sensitivity and bandwidth of the displacement sensor through a compact rotating structure.

[0005] To solve the above technical problems, the present invention provides the following technical solutions: The present invention provides a dynamic displacement sensor calibration device based on a rotating sine-edge turntable, which includes a signal generation module that drives a sine-edge turntable to rotate based on a rotation speed generating device to generate multi-band standard sine displacement signals, and converts the rotational motion into a periodic radial sine displacement change by adding a sine-edge turntable; an amplitude-frequency adjustment module that adjusts the displacement amplitude by replacing sine-edge turntables with different amplitudes according to the requirements of the periodic radial sine displacement change, and adjusts the rotation speed parameter of the rotation speed generating device to change the displacement frequency; a synchronous acquisition module that deploys a standard dynamic displacement sensor and a sensor to be measured in parallel installation to synchronously acquire sine displacement signals and the output signals of the sensor to be measured; a feature extraction module that locks the characteristic frequency of the standard displacement according to the synchronously acquired dual-channel signals, separates the amplitudes of the in-phase components of the sensor output by combining an envelope extraction algorithm and an adaptive frequency doubling notch filter, and compares the amplitudes of the time-domain signals using a polynomial regression model to calculate the dynamic sensitivity parameter; a bandwidth calibration module that generates an amplitude-frequency characteristic curve based on the dynamic sensitivity parameter by presetting an attenuation threshold, and calculates the sensor bandwidth using a least squares fitting algorithm.

[0006] As a preferred embodiment of the dynamic displacement sensor calibration device based on a rotating sinusoidal edge turntable according to the present invention, wherein: the conversion of the rotating motion of the sinusoidal edge turntable into a periodic radial sinusoidal displacement change includes the following steps, Establish a polar coordinate system with the center of the sinusoidal edge turntable as the origin, and select the arc length B of the center line of one sinusoidal period of the sinusoidal edge turntable according to the diameter of the probe of the displacement sensor to be measured c ; According to the bandwidth w of the displacement sensor to be measured s and the maximum rotation frequency f of the rotation speed generating device r Design the number of sinusoidal periods k on the edge of the turntable so that the number of sinusoidal periods k satisfies: , Calculate the center line radius R0 of the sinusoidal edge curve as: , Calculate the radian corresponding to one sinusoidal period as: , Select the amplitude A0 of the sinusoidal edge according to the range of the displacement sensor to be measured; In the polar coordinate system, the edge curve of the turntable is designed as: , wherein, is the angle between the line connecting any point on the edge of the turntable and the center of the turntable and the Y-axis of the rectangular coordinate system, and the range is .

[0007] Establish a rectangular coordinate system with the center of the turntable as the origin (0, 0) for the edge curve of the turntable, and convert the edge curve of the turntable into a rectangular coordinate system expression as: , where x and y are the coordinate values of any point on the edge of the turntable respectively.

[0008] As a preferred embodiment of the dynamic displacement sensor calibration device based on a rotating sinusoidal edge turntable according to the present invention, wherein: the rotation speed generating device includes a switch to select automatic mode and manual mode; In the automatic mode, generate a rotation frequency control command according to the starting rotation frequency, the maximum rotation frequency, the calibration point interval, the steady speed time and the acceleration; in the manual mode, control the rotation frequency through the target rotation frequency and the acceleration; the rotation frequency control cooperates with the sinusoidal edge turntable to automatically generate standard sinusoidal displacements in different frequency bands.

[0009] As a preferred embodiment of the dynamic displacement sensor calibration device based on a rotating sine-edge turntable according to the present invention, wherein: the dual-channel signals refer to the sine displacement signal output by the dynamic displacement sensor and the signal output by the displacement sensor to be measured, and the two are synchronously collected and respectively input into the adaptive same-frequency extractor.

[0010] As a preferred embodiment of the dynamic displacement sensor calibration device based on a rotating sine-edge turntable according to the present invention, wherein: the feature extraction module includes, By calculating the current rotation frequency in real time and matching the sine frequency parameters corresponding to the sine-edge turntable, the numerator and denominator terms of the transfer function of the adaptive same-frequency extractor are updated, and the parameters are dynamically adjusted to make the center frequency match the standard displacement characteristic frequency; Absolute value transformation, low-pass filtering, and gain amplification processing are performed through the envelope extraction algorithm; By calculating the double-frequency parameters corresponding to the sine frequency of the current rotating sine-edge turntable in real time, the numerator and denominator terms of the transfer function of the adaptive frequency doubling notch filter are updated.

[0011] As a preferred embodiment of the dynamic displacement sensor calibration device based on a rotating sine-edge turntable according to the present invention, wherein: the dynamic displacement sensor and the sensor to be measured adopt a coaxial installation structure, and the detection axes of their probes are located in the same tangent direction of the sine-edge turntable.

[0012] As a preferred embodiment of the dynamic displacement sensor calibration device based on a rotating sine-edge turntable according to the present invention, wherein: the feature extraction module is integrated in the human-computer interaction interface, and the amplitude, sine cycle number, and rotation speed parameters of the turntable are input through the turntable parameter setting module, and the calibration results are visualized in real time in the data visualization area of the interaction interface.

[0013] As a preferred embodiment of the dynamic displacement sensor calibration device based on a rotating sine-edge turntable according to the present invention, wherein: the polynomial regression model generates dynamic sensitivity parameters by comparing the peak-to-peak values of the standard signal and the signal to be measured after synchronous processing.

[0014] As a preferred embodiment of the dynamic displacement sensor calibration device based on a rotating sine-edge turntable according to the present invention, wherein: the method for establishing the polynomial regression model includes the following steps, Collect the peak-to-peak value sample sets of the dynamic displacement sensor and the sensor to be measured at different rotation speeds; Normalize the input and output data to the same dimension through feature scaling, determine the optimal polynomial order using the leave-one-out cross-validation method, and solve the regression coefficient matrix using the regularized least squares method to save the reference parameters.

[0015] As a preferred embodiment of the dynamic displacement sensor calibration device based on a rotating sine-edge turntable according to the present invention, where: the preset attenuation threshold refers to the critical point set according to the sensitivity attenuation characteristics of the amplitude-frequency characteristic curve.

[0016] The beneficial effects of the present invention are as follows: Through the synergistic effect of the sine-edge turntable and the rotational speed generating device, high-frequency and large-amplitude standard sine displacements can be generated with limited volume and cost, effectively solving the technical bottleneck in the generation of high-frequency and large-amplitude displacements by traditional vibration tables; By adopting an adaptive co-frequency extractor combined with envelope extraction and frequency doubling notch filtering techniques, high-precision synchronous measurement and interference suppression of dynamic displacement signals are achieved, ensuring the reliability of calibration data; The human-machine interaction interface developed based on LabVIEW integrates parameter configuration, real-time monitoring, and curve analysis functions, significantly improving the calibration efficiency of the sensor sensitivity and bandwidth; The overall device takes into account calibration accuracy and engineering applicability through modular design, providing a standardized solution for the dynamic performance evaluation of displacement sensors in industrial scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for description in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can obtain other drawings without creative efforts based on these drawings.

[0018] Figure 1 It is a schematic diagram of a dynamic displacement sensor calibration device based on a rotating sine-edge turntable.

[0019] Figure 2 It is a two-dimensional plane coordinate diagram of the sine-edge turntable.

[0020] Figure 3 It is a diagram showing the relationship between the angle of the sine-edge turntable and the dynamic standard displacement.

[0021] Figure 4 It is a time-domain diagram of the dynamic standard displacement based on the sine-edge turntable.

[0022] Figure 5 It is the core signal processing algorithm of the device.

[0023] Figure 6 It is the upper computer interface of this dynamic displacement sensor calibration device. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention will be made in conjunction with the accompanying drawings of the specification.

[0025] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention may be practiced in other ways than those specifically described herein, and those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0026] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation manner of the present invention. The phrase "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0027] Referring to Figures 1 to 6 , as an embodiment of the present invention, this embodiment provides a calibration device for a dynamic displacement sensor based on a rotating sine-edge turntable, including the following steps: The present invention mainly consists of a standard dynamic displacement generating device, a signal acquisition and controller system, a core operation module, a human-machine interaction interface, and a position-adjustable mounting base.

[0028] Furthermore, the functional modules of the device of the present invention can be classified as follows: The standard dynamic displacement generating device includes a signal generation module (driving a sine-edge turntable by a rotational speed generating device to generate multi-band standard sine displacement signals) and the hardware part of an amplitude-frequency adjustment module (adjusting the displacement amplitude and frequency upper limit by replacing turntables with different amplitudes / periods); the signal acquisition and controller system corresponds to a synchronous acquisition module, deploying a dynamic displacement sensor and a sensor to be measured in parallel installation to achieve synchronous signal processing; the core operation module covers a feature extraction module (locking the standard displacement characteristic frequency and separating the amplitude of the in-phase components through an adaptive in-phase frequency extractor, an envelope extraction algorithm, and an adaptive frequency doubling notch filter) and the algorithm part of a bandwidth calibration module (fitting an amplitude-frequency characteristic curve based on dynamic sensitivity parameters and calculating the bandwidth using the least squares algorithm); the human-machine interaction interface integrates the software control of the amplitude-frequency adjustment module (setting rotational speed parameters to change the standard sine displacement frequency), the interactive display of the bandwidth calibration module (attenuation threshold determination, curve visualization), and real-time parameter monitoring functions; the position-adjustable mounting base serves as a hardware carrier, providing physical support for turntable installation, sensor fixation, and mechanical eccentric structures, ensuring the spatial accuracy and stability when each module operates in coordination.

[0029] Among them, the standard dynamic displacement generating device is composed of a speed generating device and a sinusoidal edge turntable. The speed generating device can provide a high-precision standard speed, and the speed value can be set by the upper computer interface. The sinusoidal edge turntable is installed on the rotating shaft of the speed generating device to ensure that the central axis of the sinusoidal edge turntable is coaxial with the rotor axis of the speed generating device. The standard dynamic displacement generating device usually has a set of sinusoidal edge turntables with different amplitudes A0, different centerline radii R0, and different sinusoidal period numbers k. The appropriate turntable can be selected according to the estimated range, bandwidth, and sensor probe size of the displacement sensor to be calibrated. If necessary, the turntable can be customized according to the range, bandwidth, and other parameters of the displacement sensor to be calibrated.

[0030] When the displacement sensor to be measured is fixed to one side of the turntable and the probe direction points to the center of the turntable, the speed generating device cooperates with the sine edge turntable to generate a dynamic standard sinusoidal displacement relative to the sensor probe to be measured, and the frequency f of the generated standard sinusoidal displacement is the rotation frequency f of the rotation shaft of the speed generating device. r The product of the number of sine periods k in one cycle of the sine edge turntable. The amplitude of the standard sine displacement is the amplitude A0 of the sine edge turntable. The frequency f can be generated by adjusting the speed of the speed generator through the human-computer interaction interface. sinmax =k×f rmax The standard sinusoidal displacement of any frequency is: rmax It is the maximum speed of the speed generating device.

[0031] The host computer interface is written by the software labview, and the input controls in the interface include the starting frequency f rstart , maximum frequency f rmax , calibration point frequency switching interval d fr , Calibration point steady speed time T r And the acceleration a, the number of sinusoidal cycles k in one cycle of the sinusoidal edge turntable, the turntable amplitude A0, and the envelope extraction module low-pass cutoff frequency w c , Adaptive same-frequency extraction coefficient k qf and adaptive frequency notch coefficient k nf ; The selection switch has a speed control mode selection switch; the signal value display module can display the standard sine frequency fsin, the standard sine displacement peak-to-peak value A vpp , displacement sensor output peak-to-peak value V pp , displacement sensor output frequency f ssin , the sensitivity S of the displacement sensor to be measured, the bandwidth w of the displacement sensor to be measured s The test result image display module can display the amplitude-frequency characteristic curve of the displacement sensor to be tested, the standard sinusoidal displacement provided by the sinusoidal edge turntable and the time domain diagram of the displacement signal output by the displacement sensor to be tested, the standard displacement spectrum and the displacement spectrum diagram of the displacement sensor to be tested.

[0032] Among them, the core operation module is mainly used to obtain the standard sine displacement and the sine displacement signal of the displacement sensor to be calibrated at the current rotation frequency f r and calculate the sensitivity of the displacement sensor to be measured; finally, plot the amplitude-frequency characteristic curve of the displacement sensor to be measured and calculate the bandwidth. Its core algorithm is mainly composed of a cascade of an adaptive same-frequency extractor, an envelope extraction module, and an adaptive double-frequency notch filter. Here, the same frequency and double frequency refer to the frequency relative to the standard sine displacement. This module is a general signal processing module in the present invention, which can be used to process signals from both standard displacement sensors and displacement sensors to be measured. The device can provide a standard sine signal through a rotating sine-edge turntable. However, due to possible installation eccentricity, unbalanced vibration, and circuit noise interference of the turntable, interference signals with frequencies different from f sin =k×f r will be generated. In order to extract the standard sine displacement signal, first, the signal is passed through an adaptive same-frequency extractor, which can extract the sine signal with a frequency of f sin ; then the signal is passed through an envelope extraction module, which first takes the absolute value of the signal and then filters out the high-frequency signal to extract the amplitude envelope of the sine signal; considering that the absolute value transformation will introduce a relatively large double-frequency interference with a frequency of f dsin =2×k×f r and it is not easy to be filtered out. Therefore, finally, the envelope signal is input into an adaptive double-frequency notch filter to filter out the disturbance signal with a frequency of f dsin introduced in the envelope module.

[0033] As Figure 1 shown, the dynamic displacement sensor calibration device based on a rotating sine-edge turntable mainly includes a sine-edge turntable, a standard displacement sensor, a speed generating device, a controller, and a human-machine interface. Among them, the working process of the device is as follows: select appropriate sine-edge turntable and speed generating device parameters according to the estimated sensitivity, range, and bandwidth of the displacement sensor to be measured, including the amplitude A0 of the sine-edge turntable, the number k of sine periods in one revolution of the sine-edge turntable, and the maximum speed f rmax of the speed generating device; then place the displacement sensor to be measured and the standard displacement sensor parallel to one side of the sine-edge turntable so that the measured rotor physical displacements are the same; then start the speed generating device through the human-machine interface and the controller to make it vary within the range of 0 to the maximum rotation frequency f rmax , and at the same time read the output of the displacement sensor to be measured and the output of the standard displacement sensor; then calculate the sensitivity of the displacement sensor to be measured at each speed calibration point, and finally plot the amplitude-frequency characteristic curve of the displacement sensor to be measured and calculate the bandwidth.

[0034] As Figure 2As shown, when the sine-edge turntable rotates at a constant speed, it can generate a sine displacement relative to the probe of the sensor to be measured (for example, the amplitude A0 of the sine edge within about one-third to two-thirds of the range of the displacement sensor to be measured is selected according to the range). Taking the center of the turntable as the origin O, a polar coordinate system and a rectangular coordinate system are established. The curve of the turntable edge can be expressed in the polar coordinate system as: , where, is the radian corresponding to one sine period, and there is , R0 is the radius of the center line of the turntable edge curve, and A0 is the amplitude of the sine curve.

[0035] Specifically, taking the center of the sine-edge turntable as the origin, a polar coordinate system is established. According to the diameter of the probe of the displacement sensor to be measured (such as a multiple more than ten times the diameter), the arc length B of the center line of one sine period of the sine-edge turntable is selected c ; According to the bandwidth w of the displacement sensor to be measured s and the maximum rotational frequency f of the rotational speed generating device r the number of sine periods k of the turntable edge is designed so that the number of sine periods k satisfies: , The radius R0 of the center line of the sine-edge curve is calculated as: , The radian corresponding to one sine period is calculated as: , The amplitude A0 of the sine edge is selected according to the range of the displacement sensor to be measured; Preferably, through the design of the turntable edge curve, the radial displacement change between the sine edge and the probe of the sensor to be measured during rotation can be a standard sine.

[0036] In the rectangular coordinate system established with the center of the turntable as the origin (0, 0), it can be expressed as: , where, x and y are the coordinate values of any point on the turntable edge respectively, is the angle between the line connecting the point (x, y) on the turntable edge and the center of the turntable and the Y axis of the rectangular coordinate system, and its range is ; B c is the arc length of a circle with radius R0 corresponding to one sine period of the sine-edge turntable, . The coordinates of each point of the sine-edge turntable can be obtained according to the above method during processing.

[0037] Such as Figure 3 shown, when the turntable edge is processed into Figure 2When the sine curve shown is considered, the probe of the displacement sensor to be measured is installed at an appropriate position on the Y-axis, at a suitable distance from the edge of the turntable and pointing towards the origin O. When the turntable rotates uniformly for one week, the sine-edge turntable will generate k standard dynamic sine displacements with an amplitude of A0. The relationship between this sine displacement and the included angle is described as: , As Figure 4 shown, when the turntable rotates at a rotational frequency f r , due to , the dynamic distance ρ dy(t) between the edge of the turntable and the sensor probe is: , where r is the initial phase. The dynamic distance between the dynamic displacement sensor probe and the edge of the turntable will present as a standard sine displacement. The amplitude A0 of the sine displacement can be adjusted by designing and installing different sine-edge turntables. The frequency of the sine displacement can be adjusted by adjusting the rotational frequency f

[0038] of the rotational speed generating device and the number of sine periods k in one week of the designed and installed sine-edge turntable. Figure 5 shown, the core operation module of the dynamic displacement sensor calibration device based on the rotating sine-edge turntable is mainly composed of an adaptive co-frequency extractor, an envelope extraction module, and an adaptive frequency doubling notch filter in cascade. When the signal of the displacement sensor to be measured or the signal of the standard displacement sensor is collected and input into the core operation module, it is represented by X in ; when the approximate number of sine waves in one week of the sine-edge turntable is k and the rotational frequency of the rotating shaft is f r , the transfer function and amplitude-frequency characteristic function of the adaptive co-frequency extractor are: , , where . It can be seen that through the adaptive co-frequency extractor, the component with a frequency of in in the signal X of the displacement sensor to be measured or the standard displacement sensor can be extracted, and the output is c(t). Figure 5 The envelope extraction module in is composed of an absolute value transformation, a low-pass filter, and an amplification module. After passing through the envelope extraction module, the envelope of c(t) can be extracted and recorded as d(t). However, due to the existence of the absolute value transformation module, the interference signal with a frequency of is mixed into d(t). Therefore, it is filtered out through the adaptive frequency doubling notch filter. The transfer function and amplitude-frequency characteristic curve of the adaptive frequency doubling notch filter are: , It can be seen that after passing through the adaptive notch filter module, d(t) can filter out the interference signal with a frequency of , making the final output X out an envelope curve with less interference, which is convenient for reading the amplitude of the in-phase component of the displacement signal.

[0039] Furthermore, the peak-to-peak values of the standard signal and the signal to be measured are compared through a polynomial regression model: First, the peak-to-peak values of the synchronized signals are aligned according to the time series and the clock deviation is compensated. Subsequently, a quadratic regression equation containing non-linear error terms is established, and the dynamic sensitivity parameters are solved using the least squares method. Finally, the reliability is verified through residual analysis.

[0040] It should also be noted that the establishment of the polynomial regression model is based on the peak-to-peak value sample sets of the dynamic displacement sensor and the sensor to be measured at different rotational speeds collected from historical calibration data. The input and output data are normalized to the same dimension through feature scaling. The leave-one-out cross-validation method is used to determine the optimal polynomial order to avoid overfitting. The regression coefficient matrix is solved using the regularized least squares method to save the reference parameters for calculating the dynamic sensitivity parameters. During the real-time calibration process, online residual monitoring is used to dynamically adjust the model weights to ensure the optimal fitting accuracy in different rotational speed ranges.

[0041] As Figure 6 shown, the upper computer operation interface of the dynamic displacement sensor calibration device based on the rotating sine-edge turntable is written based on the software LabVIEW. The interface mainly includes a rotational speed generating device control module, a turntable parameter setting module, a signal processing parameter setting module, a signal numerical display module, and a test result image display module. Among them, the rotational speed generating device control module can select the automatic mode and the manual mode through the rotational speed control mode selection switch. In the automatic mode, it is necessary to input the specific values of the starting rotational frequency f rstart , the highest rotational frequency f rmax , the rotational frequency interval d of the calibration points fr , the steady speed time T of the calibration points r , and the acceleration a in the input control. Then click the motor start button. The rotational speed generating device will accelerate from zero rotational frequency to the starting rotational frequency f rstart at an acceleration of a, and then continue to accelerate at an acceleration of a, and successively accelerate to the next calibration rotational frequency point at the rotational frequency interval d of the calibration points fr , and steady speed at this rotational frequency position for T r seconds. Subsequently, repeat the acceleration and steady speed processes until accelerating to the highest rotational frequency f rmax . During the T r seconds of steady speed at each calibration point, the program will automatically execute the data acquisition and analysis calculation process, and partially display it in the parameter display module and the image display module, such as the standard sine frequency fsin , the standard sine displacement peak-to-peak value A vpp , the displacement sensor output peak-to-peak value V pp , the displacement sensor output frequency f ssin , the sensitivity S of the displacement sensor to be measured, the bandwidth w of the displacement sensor to be measured s . When the motor stop button is clicked, the speed generating device will decelerate to zero with an acceleration of -a. At the same time, the program will automatically summarize the amplitudes at the calibration points and fit the amplitude-frequency characteristic curve of the displacement sensor to be measured and display it in the image display module, and calibrate the bandwidth through a preset attenuation threshold (such as -3dB): scan the frequency points on the fitting curve where the sensitivity decays to the threshold, calculate the cut-off frequency through linear interpolation, and generate a multi-threshold verification report.

[0042] It should be noted that the method for obtaining the preset attenuation threshold is as follows: according to the technical specifications or performance requirements of the sensor application scenario, the default attenuation decibel value (such as -3dB) of the bandwidth calibration module program corresponds to the frequency as the bandwidth of the displacement sensor, and the relative attenuation ratio of the normalized amplitude-frequency characteristic curve (such as the amplitude at -3dB decays to 70.7%). At the same time, it supports importing an external configuration file to read the customized threshold for a specific application scenario. All set parameters are stored in the configuration database for subsequent calibration processes to call. When the user does not actively set, the -3dB recommended by the International Electrotechnical Commission is used as the reference threshold by default to ensure the industry universality of the measurement results.

[0043] Furthermore, the application method of the preset attenuation threshold is as follows: based on the normalized amplitude-frequency characteristic curve, set the critical value of the sensitivity attenuation as the judgment benchmark, scan the curve data points along the positive direction of the frequency axis. When the first interval where the amplitude is lower than the preset attenuation threshold is detected, extract the frequency and amplitude data of the adjacent sampling points on both sides of this interval, calculate the exact intersection frequency of the curve and the threshold line through linear interpolation as the cut-off frequency candidate value, and perform harmonic interference analysis and confidence verification on the candidate value. If the signal-to-noise ratio condition is met, it is confirmed as the effective bandwidth. Finally, the threshold line, cut-off frequency mark, and bandwidth verification report are synchronously displayed in the interactive interface to complete the quantitative calibration of the dynamic performance of the sensor.

[0044] When the manual mode is selected, the target rotation frequency f can be set rsetWith acceleration b, when the motor is clicked to start, the rotational speed generating device will stabilize the rotational frequency of the rotating shaft at the target rotational frequency. When it is necessary to adjust the rotational frequency, just input the target value in the target rotational frequency input control. In the control module of the rotational speed generating device, the current rotational frequency display control can display the rotational frequency at the current moment. The rotational frequency refresh time control can control the time interval for refreshing the value of the current rotational frequency display control. The turntable parameter setting module needs to be set according to the actual parameters of the sine-edge turntable currently installed on the rotating shaft of the rotational speed generating device. The parameters that need to be set before each experiment are the number of sine periods k in one week of the sine-edge turntable and the turntable amplitude A0. The signal processing parameter setting module can set the low-pass cut-off frequency w c of the envelope extraction module, the adaptive same-frequency extraction coefficient k qf and the adaptive multiple-frequency notch coefficient k nf . The signal value display module can display the standard sine displacement frequency value f sin , the standard sine displacement peak-to-peak value A vpp , the peak-to-peak value V of the displacement sensor output pp , the sine frequency f of the displacement sensor output ssin , and the sensitivity S of the displacement sensor to be measured. These parameters can be automatically refreshed when the rotational frequency reaches the calibration point in the automatic mode of rotation control, or after the rotational frequency is stabilized at the target rotational frequency in the manual mode, click the refresh button of the signal display module to perform background program operations and refresh the data, and at the same time store the previous set of data for later estimation of the bandwidth of the displacement sensor to be measured and drawing the amplitude-frequency characteristic curve of the displacement sensor to be measured. After the test is completed, based on the dynamic sensitivity data of each calibration point, use the least squares fitting algorithm to construct the amplitude-frequency characteristic curve: normalize the sensitivity parameter and then fit the second-order transfer function model, and minimize the error between the curve and the measured data through optimization iteration to provide a benchmark for bandwidth determination.

[0045] Furthermore, click the start calculation button, and the background program will automatically calculate the bandwidth of the displacement sensor to be measured and draw the amplitude-frequency characteristic curve of the displacement sensor to be measured. In the test result image display module, the standard displacement and the displacement diagram of the displacement sensor to be measured can display the standard sine displacement provided by the rotating sine-edge turntable and the displacement signal output by the displacement sensor to be measured; the standard displacement and the displacement frequency spectrum diagram of the displacement sensor to be measured can display the frequency spectrum of the standard displacement and the frequency spectrum of the displacement signal output by the displacement sensor to be measured.

[0046] In summary, through the synergistic effect of the sine-edge turntable and the rotational speed generating device, the present invention can generate a standard sine displacement with high frequency and large amplitude under limited volume and cost, effectively solving the technical bottleneck in the generation of high-frequency and large-amplitude displacement by traditional vibration tables; by adopting an adaptive co-frequency extractor combined with envelope extraction and frequency doubling notch filtering technologies, high-precision synchronous measurement and interference suppression of dynamic displacement signals are achieved, ensuring the reliability of calibration data; the human-computer interaction interface developed based on LabVIEW integrates parameter configuration, real-time monitoring, and curve analysis functions, significantly improving the calibration efficiency of the sensitivity and bandwidth of sensors; the overall device takes into account calibration accuracy and engineering applicability through modular design, providing a standardized solution for the dynamic performance evaluation of displacement sensors in industrial scenarios.

[0047] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A dynamic displacement sensor calibration device based on a rotating sine-edge turntable, characterized in that: Including, A signal generation module that drives a sine-edge turntable to rotate based on a rotational speed generating device to generate a multi-band standard sine displacement signal, and the sine-edge turntable converts the rotational motion into a periodic radial sine displacement change; An amplitude-frequency adjustment module that adjusts the displacement amplitude by replacing sine-edge turntables with different amplitudes according to the requirements of the periodic radial sine displacement change, and adjusts the rotational speed parameter of the rotational speed generating device to change the displacement frequency; A synchronous acquisition module that deploys a standard dynamic displacement sensor and a sensor under test to be installed in parallel, and synchronously acquires the sine displacement signal and the output signal of the sensor under test; A feature extraction module that, according to the two-channel signals after synchronous processing, locks the standard displacement characteristic frequency through an adaptive co-frequency extractor, separates the amplitude of the co-frequency component output by the sensor by combining an envelope extraction algorithm, suppresses the double-frequency component through an adaptive double-frequency notch filter, and uses a polynomial regression model to compare the peak-to-peak values of the time-domain signals to calculate the dynamic sensitivity parameter; A bandwidth calibration module that, based on the dynamic sensitivity parameter, fits the amplitude-frequency characteristic curve by presetting an attenuation threshold and based on the least squares method, and calculates the sensor bandwidth according to the amplitude attenuation; The sine-edge turntable converting the rotational motion into a periodic radial sine displacement change includes the following steps, Establish a polar coordinate system with the center of the sine-edge turntable as the origin, and select the arc length B of the center line of a sine period of the sine-edge turntable according to the diameter of the probe of the displacement sensor to be measured c ; According to the bandwidth w of the displacement sensor to be measured s and the maximum rotational frequency f of the rotational speed generating device r Design the number of sine periods k at the edge of the turntable so that the number of sine periods k satisfies: , Calculating the center line radius R0 of the sine-edge curve and the radian corresponding to one sine period; Selecting the amplitude A0 of the sine-edge according to the range of the displacement sensor under test; In the polar coordinate system, the turntable edge curve is designed as: , Among them, is the angle between the line connecting any point on the edge of the turntable and the center of the turntable and the Y-axis of the rectangular coordinate system, and the range is ; Establishing a rectangular coordinate system with the turntable edge curve with the turntable center as the origin (0, 0), and converting the turntable edge curve into a rectangular coordinate system expression as: , Where x and y are the coordinate values of any point on the turntable edge respectively.

2. The dynamic displacement sensor calibration device based on a rotating sine-edge turntable according to claim 1, wherein: The rotational speed generating device includes a switch to select automatic mode and manual mode; In the automatic mode, a rotational frequency control command is generated according to the starting rotational frequency, the highest rotational frequency, the calibration point interval, the steady speed time, and the acceleration; in the manual mode, the rotational frequency is controlled by the target rotational frequency and the acceleration; the rotational frequency control cooperates with the sine-edge turntable to automatically generate standard sine displacements in different frequency bands.

3. The dynamic displacement sensor calibration device based on a rotating sine-edge turntable according to claim 2, wherein: The two-channel signals refer to the sine displacement signal output by the dynamic displacement sensor and the signal output by the displacement sensor under test, and the two are synchronously acquired and respectively input into the adaptive co-frequency extractor.

4. The dynamic displacement sensor calibration device based on a rotating sine-edge turntable according to claim 1, characterized in that: The feature extraction module includes, By calculating in real time the sine frequency parameter corresponding to the current rotational frequency cooperating with the sine-edge turntable, updating the numerator term and the denominator term of the transfer function of the adaptive co-frequency extractor, and dynamically adjusting the parameters to make the center frequency match the standard displacement characteristic frequency; Performing absolute value transformation, low-pass filtering, and gain amplification processing through an envelope extraction algorithm; By calculating in real time the double-frequency parameter of the sine frequency corresponding to the current rotating sine-edge turntable, updating the numerator term and the denominator term of the transfer function of the adaptive double-frequency notch filter.

5. The dynamic displacement sensor calibration device based on a rotating sine-edge turntable according to claim 1, characterized in that: The standard dynamic displacement sensor and the sensor under test adopt a coaxial installation structure, and the detection axes of their probes are located in the same tangent direction of the sine-edge turntable.

6. The dynamic displacement sensor calibration device based on a rotating sine-edge turntable as claimed in claim 1, characterized in that: The feature extraction module is integrated in the human-machine interaction interface, and the turntable amplitude, the number of sine periods, and the rotational speed parameter are input through the turntable parameter setting module, and the calibration results are visualized in real time in the data visualization area of the interaction interface.

7. The dynamic displacement sensor calibration device based on a rotating sine-edge turntable according to claim 1, wherein: The polynomial regression model generates a dynamic sensitivity parameter by comparing the peak-to-peak values of the standard signal and the signal to be measured after synchronous processing.

8. The dynamic displacement sensor calibration device based on a rotating sine-edge turntable according to claim 7, characterized in that: The method for establishing the polynomial regression model includes the following steps: Collect the peak-to-peak value sample sets of the dynamic displacement sensor and the sensor to be measured at different rotational speeds; Normalize the input and output data to the same dimension through feature scaling, determine the optimal polynomial order using the leave-one-out cross-validation method, and solve the regression coefficient matrix using the regularized least squares method to save the reference parameters.

9. The dynamic displacement sensor calibration device based on a rotating sine-edge turntable according to claim 1, wherein: The preset attenuation threshold refers to the critical point set according to the sensitivity attenuation characteristics of the amplitude-frequency characteristic curve.

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