Method and system for reducing reproduced wave error

Abstract

The invention relates to a method and a system for reducing an error of a reproduced wave, belongs to the technical field of vibration wave calibration, and solves the problems that a method for calibrating and correcting the reproduced wave in the prior art is high in threshold and long in time consumption, and results cannot be reused. Obtaining an input signal, inputting the input signal into the micro-vibration test bench, and collecting an output signal of the micro-vibration test bench; converting the output signal into an output frequency domain signal based on Fourier transform, converting the original reproduced wave signal into an original frequency domain signal, and determining whether the amplitude difference between the output frequency domain signal and the original frequency domain signal under each frequency in each direction is smaller than a preset error threshold value or not according to spectrum distribution; if the amplitude difference in each direction is smaller than a preset error threshold, taking the input signal as a reproduction wave input signal; if not, adjusting operation is executed, and the signals in all the directions in the input signals and the error adjusting signals in the corresponding directions are superposed to regenerate the input signals. The reproduced wave debugging method which is simple to operate and high in efficiency is realized.

Description

Technical Field

[0001] The present invention relates to the field of vibration wave calibration technology, and in particular to a method and system for reducing reproduction wave error. Background Art

[0002] The micro-vibration test bench is mainly used to simulate and test the micro-vibration environment to evaluate the stability and reliability of the equipment or structure in the actual working environment. It can simulate various vibration conditions, such as sine wave, frequency modulation, frequency sweep, programmable, frequency doubling, logarithmic, etc., to meet the testing requirements of different industries. After the micro-vibration test bench inputs the reproduced wave, its response output wave generally has different degrees of error. This error may come from the self-vibration characteristics of the vibration system composed of the test bench and the test object. In order to ensure the accuracy, reliability and repeatability of the test results, before the formal test of the test object, the input reproduced wave should be calibrated and corrected to keep the error of the test bench response wave in each frequency band within the allowable range.

[0003] In the prior art, the general method for calibrating and correcting the reproduced wave is to use cosine wave frequency sweep to find the isotropic natural frequencies of the test object or vibration system, and then use a notch filter to suppress the signal of the specific frequency to ensure that there is no excitation at the resonance peak. However, the notch filter filtering needs to be based on different test objects and the waveform of the reproduced wave, and needs to be repeatedly debugged by professionals. It has a high threshold, is time-consuming, and the results cannot be reused.

[0004] Therefore, there is no simple and efficient reproduction wave debugging method in the prior art. Summary of the invention

[0005] In view of the above analysis, the embodiments of the present invention aim to provide a method and system for reducing the error of the reproduced wave, so as to solve the problems that the existing methods for calibrating and correcting the reproduced wave have high thresholds, are time-consuming, and the results cannot be reused.

[0006] On the one hand, an embodiment of the present invention provides a method for reducing a reproduction wave error, comprising:

[0007] S1: Place the device under test on the micro-vibration test bench;

[0008] S2: obtaining an input signal, inputting the input signal into the micro-vibration test bench, and collecting an output signal of the micro-vibration test bench;

[0009] S3: Based on Fourier transform, the output signal is converted into an output frequency domain signal and the original reproduced wave signal is converted into an original frequency domain signal, and it is determined whether the amplitude difference between the output frequency domain signal and the original frequency domain signal at each frequency in each direction is less than a preset error threshold according to the spectrum distribution, wherein the original reproduced wave refers to the external three-way random vibration time-history wave signal collected by the vibration sensor to which the device under test is subjected in the actual working scenario;

[0010] S4: If the amplitude difference in each direction is less than the preset error threshold, the input signal is used as the reconstructed wave input signal; if not, the following operations are performed:

[0011] For a direction where the amplitude difference is greater than a preset error threshold, a plurality of continuous frequency points where the amplitude difference is greater than the preset error threshold are taken as a frequency band to be corrected, and an error adjustment signal corresponding to the direction is regenerated based on each frequency band to be corrected in the direction;

[0012] The signal in each direction of the input signal is superimposed with the error adjustment signal in the corresponding direction to regenerate the input signal, and then the process returns to step S2.

[0013] Based on a further improvement of the above method, the initial value of the input signal is the original reproduced wave.

[0014] Based on a further improvement of the above method, the step of regenerating the error adjustment signal corresponding to the direction based on each frequency band to be corrected in the direction includes:

[0015] Determine the frequency center point of each frequency band to be corrected, and generate a cosine wave adjustment signal corresponding to each frequency band to be corrected based on the frequency center point of each frequency band to be corrected, a preset frequency interval, a preset bandwidth threshold, and a preset adjustment amplitude multiple of a response peak value corresponding to the frequency center point;

[0016] The various cosine wave adjustment signals are added together to generate an error adjustment signal corresponding to the direction.

[0017] Based on the further improvement of the above method, the preset error threshold is set to 0db~10db.

[0018] Based on a further improvement of the above method, the preset bandwidth threshold is 12 Hz or 6 Hz, and the preset adjustment amplitude multiple is 1 / 3, 1 / 2 or 1.

[0019] On the other hand, an embodiment of the present invention provides a system for reducing a reproduction wave error, comprising:

[0020] Vibration platform, used to place the device under test;

[0021] A signal generator, generating an input signal based on a frequency band to be corrected;

[0022] A controller, used for receiving the input signal and converting it into a control signal for driving the vibration platform actuator, wherein the control signal is transmitted to the actuator of the vibration platform through a transmission interface to make the vibration platform vibrate;

[0023] A data acquisition device, used to collect output vibration signals generated by the vibration platform;

[0024] A data processing device, based on Fourier transform, converts the output vibration signal into an output frequency domain signal and converts the original reproduced wave signal into an original frequency domain signal, and determines whether the amplitude difference between the output frequency domain signal and the original frequency domain signal at each frequency in each direction is less than a preset error threshold according to the frequency spectrum distribution;

[0025] If the amplitude difference in each direction is less than the preset error threshold, the input signal is used as the reconstructed wave input signal; if not, the following operations are performed:

[0026] For a direction where the amplitude difference is greater than a preset error threshold, a plurality of continuous frequency points where the amplitude difference is greater than the preset error threshold are taken as a frequency band to be corrected, an error adjustment signal corresponding to the direction is regenerated based on each frequency band to be corrected in the direction, and the error adjustment signal is sent to a signal generator;

[0027] The original reproduced wave refers to the external three-way random vibration time-history wave signal collected by the vibration sensor to which the device under test is subjected in an actual working scenario.

[0028] Based on the further improvement of the above system, the input signal generated by the signal generator for the first time is the original reproduced wave.

[0029] Based on the further improvement of the above system, the system further includes: a seismic isolation device, which is placed at the bottom of the vibration platform and is used to isolate the vibration platform from external vibration interference.

[0030] Based on a further improvement of the above system, the step of regenerating the error adjustment signal corresponding to the direction based on each frequency band to be corrected in the direction includes:

[0031] Determine the frequency center point of each frequency band to be corrected, and generate a cosine wave adjustment signal corresponding to each frequency band to be corrected based on the frequency center point of each frequency band to be corrected, a preset frequency interval, a preset bandwidth threshold, and a preset adjustment amplitude multiple of a response peak value corresponding to the frequency center point;

[0032] The various cosine wave adjustment signals are added together to generate an error adjustment signal corresponding to the direction.

[0033] Based on further improvement of the above system, the preset error threshold is set to 5db.

[0034] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0035] 1. The present invention provides a method and system for reducing the error of the reproduced wave. The method and system provided by the present invention are simpler and more efficient to operate than the correction method of using a notch filter to suppress signals of a specific frequency in the prior art, which is based on a correction method for continuously adjusting the input signal based on the amplitude difference between the output signal of the micro-vibration table and the original reproduced wave signal.

[0036] 2. The present invention provides a method and system for reducing the error of the reproduced wave, and the area of ​​the amplitude difference between the output signal of each micro-vibration table and the original reproduced wave signal is corrected to ensure that the input signal finally generated can accurately and reliably output the original reproduced wave within the allowable error range. In addition, the finally generated input signal is saved and can be directly called when the reproduced wave in the same scene is needed. Therefore, the output results of the method and system provided by the present invention are reusable.

[0037] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings are only used for the purpose of illustrating specific embodiments and are not to be considered as limiting the present invention. In the entire drawings, the same reference symbols represent the same components;

[0039] Figure 1 This is an exemplary diagram of a method for reducing reproduction wave error in an embodiment of the present invention. DETAILED DESCRIPTION

[0040] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0041] The present invention discloses a method and system for reducing the error of the reproduced wave. First, the device to be tested is placed in an actual working scene to collect the external disturbances to which the device to be tested is subjected in the actual working scene, and the external disturbances are collected by a vibration sensor to obtain the original reproduced wave. Then, the original reproduced wave is simulated in a laboratory, with the purpose of enabling the current micro-vibration test bench to output disturbances consistent with the external environment, thereby simulating the vibration state of the device to be tested in a real scene in a laboratory environment.

[0042] A specific embodiment of the present invention discloses a method for reducing the error of the reproduced wave, such as Figure 1 As shown, including:

[0043] S1: Place the device under test on the micro-vibration test bench.

[0044] S2: Acquire an input signal, input the input signal into the micro-vibration test bench, and collect an output signal of the micro-vibration test bench.

[0045] The initial value of the input signal is the original reproduced wave.

[0046] S3: Based on Fourier transform, the output signal is converted into an output frequency domain signal and the original reproduced wave signal is converted into an original frequency domain signal, and it is determined whether the amplitude difference between the output frequency domain signal and the original frequency domain signal at each frequency in each direction is less than a preset error threshold according to the spectrum distribution. The original reproduced wave refers to the external three-way random vibration time-history wave signal collected by the vibration sensor to which the device under test is subjected in the actual working scenario.

[0047] The original reproducing wave in the present invention refers to a three-way random wave, which is mainly used in the fields of earthquake engineering, marine engineering, etc. It can be regarded as a combination of random vibrations in three directions (for example, x, y, and z directions). For example, if x(t), y(t), and z(t) are used to represent random vibration signals in three directions, then the three-way random wave can be expressed in vector form as follows:

[0048]

[0049] The preset error threshold is set to 0 db to 10 db. Preferably, the preset error threshold is set to 5 db.

[0050] Since the original reproduced wave is a three-directional random wave, the present invention needs to determine whether there is an error threshold in each direction.

[0051] S4: If the amplitude difference in each direction is less than the preset error threshold, the input signal is used as the reconstructed wave input signal; if not, the following operations are performed:

[0052] For a direction where the amplitude difference is greater than a preset error threshold, a plurality of continuous frequency points where the amplitude difference is greater than the preset error threshold are taken as a frequency band to be corrected, and an error adjustment signal corresponding to the direction is regenerated based on each frequency band to be corrected in the direction;

[0053] The signal in each direction of the input signal is superimposed with the error adjustment signal in the corresponding direction to regenerate the input signal, and then the process returns to step S2.

[0054] It can be understood that the technical solution proposed by the present invention is to make the micro-vibration platform produce the same vibration as the original reproduction wave, so as to more accurately simulate the vibration of the object to be tested in the actual environment, and then overcome the error caused by the self-vibration characteristics of the vibration system composed of the test bench and the test object by continuously correcting the input signal. The core of the technical solution of the present invention is to continuously adjust the amplitude difference between the output signal corresponding to the current input signal and the original reproduction wave at each frequency, so that the amplitude of the output signal at any frequency is constantly close to the original reproduction wave, and finally the input signal corresponding to the original reproduction wave can be obtained.

[0055] The step of regenerating the error adjustment signal corresponding to the direction based on each frequency band to be corrected in the direction includes:

[0056] Determine the frequency center point of each frequency band to be corrected, and generate a cosine wave adjustment signal corresponding to each frequency band to be corrected based on the frequency center point of each frequency band to be corrected, a preset frequency interval, a preset bandwidth threshold, and a preset adjustment amplitude multiple of a response peak value corresponding to the frequency center point;

[0057] The various cosine wave adjustment signals are added together to generate an error adjustment signal corresponding to the direction.

[0058] Among them, the preset bandwidth threshold is 12Hz or 6Hz, and the bandwidth range refers to the area formed by both sides of the frequency center point. Preferably, the preset bandwidth threshold is 6Hz. In practical applications, if there are adjacent peaks on both sides of the current frequency center point, the bandwidth can be appropriately increased. The preset adjustment amplitude multiple is 1 / 3, 1 / 2 or 1. The preset frequency interval can be set according to actual needs, such as 0.1, 0.2 or 0.3, and the present invention is not limited here.

[0059] Determine the frequency center point of the current frequency band to be corrected as M, the preset frequency interval THz, the preset bandwidth threshold is 2BHz (i.e. ±BHz), and the response peak value corresponding to the frequency center point is A i , the preset adjustment amplitude multiple P, then the cosine wave adjustment signal corresponding to this frequency interval is:

[0060]

[0061] Among them, i=MB, M-B+T, M-B+2T, M-B+3T, ..., M+B, and t is time.

[0062] For example, the frequency center point of the current frequency band to be corrected is determined to be 20 Hz, the frequency interval is 0.2 Hz, the bandwidth is 6 Hz (ie ±3 Hz), and the response peak value corresponding to the frequency center point is A i , the preset adjustment amplitude multiple is 1 / 3, then the cosine wave adjustment signal corresponding to this frequency interval is:

[0063]

[0064] Among them, i=17, 17.2, 17.4, 17.6, ....., 23.

[0065] Exemplarily, the superposition operations in the present invention are all linear superposition operations.

[0066] It can be understood that the present invention is actually a process of superimposing the error adjustment signal with the input signal in the corresponding direction. After the superimposition operation is performed in all directions with amplitude differences, the input signal will eventually be generated.

[0067] Another specific embodiment of the present invention discloses a system for reducing reproduction wave error, comprising:

[0068] Vibration platform, used to place the device under test.

[0069] The signal generator generates an input signal based on the frequency band to be corrected, wherein the input signal first generated by the signal generator is an original reproduced wave.

[0070] The controller is used to receive the input signal and convert it into a control signal for driving the vibration platform actuator. The control signal is transmitted to the actuator of the vibration platform through a transmission interface to make the vibration platform vibrate.

[0071] The data acquisition device is used to acquire the output vibration signal generated by the vibration platform.

[0072] A data processing device, based on Fourier transform, converts the output vibration signal into an output frequency domain signal and converts the original reproduced wave signal into an original frequency domain signal, and determines whether the amplitude difference between the output frequency domain signal and the original frequency domain signal at each frequency in each direction is less than a preset error threshold according to the frequency spectrum distribution;

[0073] If the amplitude difference in each direction is less than the preset error threshold, the input signal is used as the reconstructed wave input signal; if not, the following operations are performed:

[0074] For a direction where the amplitude difference is greater than a preset error threshold, a plurality of continuous frequency points where the amplitude difference is greater than the preset error threshold are taken as a frequency band to be corrected, an error adjustment signal corresponding to the direction is regenerated based on each frequency band to be corrected in the direction, and the error adjustment signal is sent to a signal generator;

[0075] The original reproduced wave refers to the external three-way random vibration time-history wave signal collected by the vibration sensor to which the device under test is subjected in an actual working scenario.

[0076] The regenerating the error adjustment signal corresponding to the direction based on each frequency band to be corrected in the direction comprises:

[0077] Determine the frequency center point of each frequency band to be corrected, and generate a cosine wave adjustment signal corresponding to each frequency band to be corrected based on the frequency center point of each frequency band to be corrected, a preset frequency interval, a preset bandwidth threshold, and a preset adjustment amplitude multiple of a response peak value corresponding to the frequency center point;

[0078] The various cosine wave adjustment signals are added together to generate an error adjustment signal corresponding to the direction.

[0079] Among them, the preset error threshold is set to 0db~10db, preferably, the preset error threshold is set to 5db. The preset bandwidth threshold is 12Hz or 6Hz, and the bandwidth range refers to the area formed by both sides of the frequency center point. Preferably, the preset bandwidth threshold is 6Hz. In practical applications, if there are adjacent peaks on both sides of the current frequency center point, the bandwidth can be appropriately increased. The preset adjustment amplitude multiple is 1 / 3, 1 / 2 or 1.

[0080] Among them, the actuator can also be called an excitation unit, which is composed of a low-frequency excitation unit and a high-frequency excitation unit. Based on the input signal generated by the data processing device, the low-frequency excitation unit or the high-frequency excitation unit is automatically selected to control the vibration platform to generate vibration corresponding to the input signal.

[0081] The system also includes: a seismic isolation device, which is placed at the bottom of the vibration platform and is used to isolate the vibration platform from external vibration interference. The seismic isolation device includes an active seismic isolation unit and a passive seismic isolation unit. The active seismic isolation unit is composed of a low-frequency active seismic isolation unit and a high-frequency active seismic isolation unit. The passive seismic isolation unit is composed of a rigid seismic isolation unit and a flexible seismic isolation unit. In actual applications, users can select active seismic isolation units or passive seismic isolation units according to their needs to effectively isolate vibrations from the ground or the surrounding environment.

[0082] Compared with the prior art, the present embodiment provides a method and system for reducing the error of the reproduced wave. The correction method continuously adjusts the input signal based on the amplitude difference between the output signal of the micro-vibration table and the original reproduced wave signal. Compared with the correction method of the prior art that uses a notch filter to suppress signals of a specific frequency, the method and system provided by the present invention are simpler and more efficient to operate. The area of ​​the amplitude difference between the output signal of each micro-vibration table and the original reproduced wave signal is corrected to ensure that the input signal finally generated can accurately and reliably output the original reproduced wave within the allowable error range. In addition, the finally generated input signal is saved and can be directly called when the reproduced wave in the same scenario is needed. Therefore, the output result of the method and system provided by the present invention is reusable.

[0083] Those skilled in the art will appreciate that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium, wherein the computer-readable storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

[0084] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for reducing reproduction wave error, characterized in that: include: S1: Place the device under test on the micro-vibration test bench; S2: obtaining an input signal, inputting the input signal into the micro-vibration test bench, and collecting an output signal of the micro-vibration test bench; S3: Based on Fourier transform, the output signal is converted into an output frequency domain signal and the original reproduced wave signal is converted into an original frequency domain signal, and it is determined whether the amplitude difference between the output frequency domain signal and the original frequency domain signal at each frequency in each direction is less than a preset error threshold according to the spectrum distribution, wherein the original reproduced wave refers to the external three-way random vibration time-history wave signal collected by the vibration sensor to which the device under test is subjected in the actual working scenario; S4: If the amplitude difference in each direction is less than the preset error threshold, the input signal is used as the reconstructed wave input signal; if not, the following operations are performed: For a direction where the amplitude difference is greater than a preset error threshold, a plurality of continuous frequency points where the amplitude difference is greater than the preset error threshold are taken as a frequency band to be corrected, and an error adjustment signal corresponding to the direction is regenerated based on each frequency band to be corrected in the direction; The signal in each direction of the input signal is superimposed with the error adjustment signal in the corresponding direction to regenerate the input signal, and then the process returns to step S2.

2. A method for reducing reproduction wave error according to claim 1, characterized in that: include: The initial value of the input signal is the original reproduced wave.

3. A method for reducing reproduction wave error according to claim 2, characterized in that: The regenerating the error adjustment signal corresponding to the direction based on each frequency band to be corrected in the direction comprises: Determine the frequency center point of each frequency band to be corrected, and generate a cosine wave adjustment signal corresponding to each frequency band to be corrected based on the frequency center point of each frequency band to be corrected, a preset frequency interval, a preset bandwidth threshold, and a preset adjustment amplitude multiple of a response peak value corresponding to the frequency center point; The various cosine wave adjustment signals are added together to generate an error adjustment signal corresponding to the direction.

4. A method for reducing reproduction wave error according to claim 3, characterized in that: include: The preset error threshold is set to 0db-10db.

5. A method for reducing reproduction wave error according to claim 4, characterized in that: include: The preset bandwidth threshold is 12 Hz or 6 Hz, and the preset adjustment amplitude multiple is 1 / 3, 1 / 2 or 1.

6. A system for reducing reproduced wave error, characterized in that: include: Vibration platform, used to place the device under test; A signal generator, generating an input signal based on a frequency band to be corrected; A controller, used for receiving the input signal and converting it into a control signal for driving the vibration platform actuator, wherein the control signal is transmitted to the actuator of the vibration platform through a transmission interface to make the vibration platform vibrate; A data acquisition device, used to collect output vibration signals generated by the vibration platform; A data processing device, based on Fourier transform, converts the output vibration signal into an output frequency domain signal and converts the original reproduced wave signal into an original frequency domain signal, and determines whether the amplitude difference between the output frequency domain signal and the original frequency domain signal at each frequency in each direction is less than a preset error threshold according to the frequency spectrum distribution; If the amplitude difference in each direction is less than the preset error threshold, the input signal is used as the reconstructed wave input signal; if not, the following operations are performed: For a direction where the amplitude difference is greater than a preset error threshold, a plurality of continuous frequency points where the amplitude difference is greater than the preset error threshold are taken as a frequency band to be corrected, an error adjustment signal corresponding to the direction is regenerated based on each frequency band to be corrected in the direction, and the error adjustment signal is sent to a signal generator; The original reproduced wave refers to the external three-way random vibration time-history wave signal collected by the vibration sensor to which the device under test is subjected in an actual working scenario.

7. A system for reducing reproduction wave error according to claim 6, characterized in that: include: The input signal first generated by the signal generator is the original reproduced wave.

8. A system for reducing reproduction wave error according to claim 7, characterized in that: The system further comprises: a seismic isolation device, which is placed at the bottom of the vibration platform and is used to isolate the vibration platform from external vibration interference.

9. A system for reducing reproduction wave error according to claim 8, characterized in that: The regenerating the error adjustment signal corresponding to the direction based on each frequency band to be corrected in the direction comprises: Determine the frequency center point of each frequency band to be corrected, and generate a cosine wave adjustment signal corresponding to each frequency band to be corrected based on the frequency center point of each frequency band to be corrected, a preset frequency interval, a preset bandwidth threshold, and a preset adjustment amplitude multiple of a response peak value corresponding to the frequency center point; The various cosine wave adjustment signals are added together to generate an error adjustment signal corresponding to the direction.

10. A system for reducing reproduction wave error according to claim 9, characterized in that: include: The preset error threshold is set to 5db.

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