CN117145792B - Fan abnormal noise detection method and fan abnormal noise detection system - Google Patents

Abstract

The embodiment of the application provides a method and a system for detecting abnormal sound of a fan, which are applied to the technical field of testing. According to the method, a fan control module is used for controlling a cooling fan to sequentially operate at a plurality of different preset rotating speeds, when the cooling fan operates at each preset rotating speed, a driving mechanism drives the cooling fan and at least one recording element on a test bottom plate to synchronously rotate to a plurality of different rotating angles, when the cooling fan and the at least one recording element synchronously rotate to each rotating angle, at least one recording element collects sound source signals of the cooling fan once, and a different sound detection module detects whether different sounds exist in the cooling fan according to each sound source signal. Therefore, the possibility that the abnormal sound is excited in the detection process of the radiating fan with the abnormal sound can be improved, and the consistency of sound source signals acquired by the recording element under different rotation angles of the radiating fan is improved, so that the accuracy of the abnormal sound detection result of the radiating fan is improved.

Description

Fan abnormal noise detection method and fan abnormal noise detection system

Technical Field

The present application relates to the field of testing technology, and in particular to a fan abnormal noise detection method and a fan abnormal noise detection system.

Background Art

With the continuous development of electronic technology, electronic devices such as laptops have gradually become more commonly used tools in people's lives and work. Laptops and other electronic devices will generate a certain amount of heat during operation. In order to discharge the generated heat to the outside air in time, some electronic devices may be equipped with cooling fans for heat dissipation.

There may be some defects in the processing and assembly of cooling fans. These defective cooling fans may produce abnormal noise during operation, which will bring bad intuitive experience to consumers. Therefore, how to screen out cooling fans without abnormal noise is a problem that needs to be solved.

Summary of the invention

The embodiments of the present application provide a fan abnormal sound detection method and a fan abnormal sound detection system, which improves the accuracy of the abnormal sound detection results of the cooling fan by collecting the sound source signals of the cooling fan when the cooling fan runs at multiple different preset speeds and the cooling fan and at least one recording element rotate synchronously to multiple different rotation angles.

In the first aspect, the embodiment of the present application proposes a fan abnormal sound detection method, which is applied to a fan abnormal sound detection system. The fan abnormal sound detection system includes a sound source collection device and an abnormal sound detection module. The sound source collection device includes a driving mechanism, a test base plate, at least one recording element and a fan control module. The driving mechanism is connected to the test base plate and the at least one recording element respectively. A cooling fan is fixed on the test base plate. The fan control module is electrically connected to the cooling fan, and at least one recording element is electrically connected to the abnormal sound detection module. The method includes: the fan control module controls the cooling fan to operate at a plurality of different preset speeds in sequence; when the cooling fan operates at each preset speed, the driving mechanism drives the cooling fan and at least one recording element on the test base plate to rotate synchronously to a plurality of different rotation angles; when the cooling fan operates at each preset speed, and the cooling fan and at least one recording element rotate synchronously to each rotation angle, at least one recording element collects the sound source signal of the cooling fan once; at least one recording element sends each collected sound source signal to the abnormal sound detection module; the abnormal sound detection module detects whether there is abnormal sound in the cooling fan according to each sound source signal.

In this way, compared with the manual detection method, the embodiment of the present application uses a recording element to collect the sound source signal during the operation of the cooling fan, and analyzes the sound source signal through the abnormal sound detection module to automatically detect whether there is an abnormal sound in the cooling fan. During the detection process, it is less affected by the environmental noise and the subjective factors of the detection personnel, thereby improving the accuracy of the abnormal sound detection results of the cooling fan and improving the efficiency of the abnormal sound detection of the cooling fan. Furthermore, compared with using a recording element fixedly installed in a soundproof box to collect sound source signals of the cooling fan when it is running at different rotation angles to detect abnormal sounds of the cooling fan, the embodiment of the present application uses a recording element to collect sound source signals of the cooling fan when the cooling fan is at multiple different preset speeds and multiple different rotation angles. The cooling fan runs at multiple different preset speeds, which can increase the possibility that the cooling fan with abnormal sounds will be stimulated to produce abnormal sounds during the detection process, thereby improving the accuracy of the abnormal sound detection results of the cooling fan; when the cooling fan rotates to multiple different rotation angles, the recording element and the cooling fan rotate synchronously, so that when the cooling fan rotates to different rotation angles, the angle and relative position between the cooling fan and the recording element will not change, which can improve the consistency of the sound source signals collected by the recording element at different rotation angles of the cooling fan, thereby improving the accuracy of the abnormal sound detection results of the cooling fan.

In a possible implementation, the abnormal sound detection module detects whether the cooling fan has abnormal sound according to each sound source signal, including: the abnormal sound detection module calculates the average spectrum kurtosis and average spectrum peak of each sound source signal; the abnormal sound detection module calculates the sound pressure level of each sound source signal; the abnormal sound detection module determines whether the cooling fan has abnormal sound according to the average spectrum kurtosis, average spectrum peak and sound pressure level of each sound source signal. In this way, the embodiment of the present application not only considers the corresponding sound pressure level for the sound source signal of the cooling fan, but also introduces the average spectrum kurtosis and average spectrum peak, that is, the average spectrum kurtosis, average spectrum peak and sound pressure level are used to jointly determine whether the cooling fan has abnormal sound, thereby improving the interception rate of the abnormal sound detection of the cooling fan and reducing the over-kill rate of the abnormal sound detection of the cooling fan, thereby improving the accuracy of the abnormal sound detection result of the cooling fan in only one step.

In one possible implementation, the abnormal sound detection module calculates the average spectrum kurtosis and the average spectrum peak of each sound source signal, including: the abnormal sound detection module performs bandpass filtering on each sound source signal; the abnormal sound detection module performs Fourier transform on each sound source signal after the bandpass filtering to obtain the spectrum corresponding to each sound source signal; the abnormal sound detection module extracts the frequency band to be analyzed in the spectrum corresponding to each sound source signal; the abnormal sound detection module calculates the average spectrum kurtosis and the average spectrum peak of each sound source signal based on the frequency band to be analyzed corresponding to each sound source signal.

In a possible implementation, the frequency band to be analyzed includes multiple octave frequency bands corresponding to the rotation frequency of the cooling fan. The abnormal sound detection module calculates the average spectrum kurtosis and average spectrum peak of each sound source signal according to the frequency band to be analyzed corresponding to each sound source signal, including: the abnormal sound detection module calculates the spectrum kurtosis and spectrum peak corresponding to each octave frequency band included in the frequency band to be analyzed corresponding to each sound source signal; the abnormal sound detection module calculates the average value of the spectrum kurtosis corresponding to multiple octave frequency bands included in the frequency band to be analyzed corresponding to each sound source signal, and obtains the average spectrum kurtosis of each sound source signal; the abnormal sound detection module calculates the average value of the spectrum peaks corresponding to multiple octave frequency bands included in the frequency band to be analyzed corresponding to each sound source signal, and obtains the average spectrum peak of each sound source signal. In this way, since the sound source signal corresponding to the faulty cooling fan will generate many octave frequency components after Fourier transformation, therefore, based on analyzing the frequency band to be analyzed in the spectrum corresponding to each sound source signal, the average spectrum kurtosis and the average spectrum peak are calculated, so as to more accurately determine whether the cooling fan has abnormal sound.

In a possible implementation, the abnormal sound detection module calculates the sound pressure level of each sound source signal, including: the abnormal sound detection module performs high-pass filtering on each sound source signal; the abnormal sound detection module uses a human ear hearing model to filter each sound source signal after high-pass filtering; the abnormal sound detection module calculates the sound pressure level of each sound source signal after filtering using the human ear hearing model. In this way, since the abnormal sound of some cooling fans is less related to the rotation frequency, but the sound pressure level in the high frequency band has a large difference, therefore, the sound pressure level in the high frequency band is used as another part of the detection index for judging whether the cooling fan has abnormal sound, so as to more accurately determine whether the cooling fan has abnormal sound.

In a possible implementation, the abnormal sound detection module calculates the sound pressure level of each sound source signal after filtering using the human ear hearing model, including: the abnormal sound detection module calculates the sampling value corresponding to each sound source signal after filtering using the human ear hearing model, and multiplies it by the reference voltage of the analog-to-digital conversion to obtain the voltage value corresponding to each sound source signal; the abnormal sound detection module calculates the ratio of the voltage value corresponding to each sound source signal to the sensitivity of the recording element to obtain the sound pressure of each sound source signal; the abnormal sound detection module calculates the sound pressure level of each sound source signal by the following formula: SPL=20×lg(P _e /P _ref ); wherein SPL represents the sound pressure level of each sound source signal, P _e represents the sound pressure of each sound source signal, and _Pref represents the reference sound pressure.

In a possible implementation, the abnormal sound detection module determines whether the cooling fan has abnormal sound according to the average spectrum kurtosis, average spectrum peak and sound pressure level of each sound source signal, including: when the average spectrum kurtosis of each sound source signal is less than the spectrum kurtosis threshold, the average spectrum peak of each sound source signal is less than the spectrum peak threshold, and the sound pressure level of each sound source signal is less than the sound pressure level threshold, the abnormal sound detection module determines that the cooling fan does not have abnormal sound; when the average spectrum kurtosis of at least one sound source signal is greater than or equal to the spectrum kurtosis threshold, and/or the average spectrum peak of at least one sound source signal is greater than or equal to the spectrum peak threshold, and/or the sound pressure level of at least one sound source signal is greater than or equal to the sound pressure level threshold, the abnormal sound detection module determines that the cooling fan has abnormal sound. In this way, by comparing the average spectrum kurtosis, average spectrum peak and sound pressure level of the sound source signal with their respective corresponding thresholds, it is determined whether the cooling fan has abnormal sound, which improves the interception rate of the abnormal sound detection of the cooling fan and reduces the over-kill rate of the abnormal sound detection of the cooling fan, thereby improving the accuracy of the abnormal sound detection result of the cooling fan in only one step.

In a possible implementation, the fan control module includes a host controller, a voltage output module and a counter module, the host controller is electrically connected to the voltage output module and the counter module respectively, and the voltage output module and the counter module are also electrically connected to the heat dissipation fan. The fan control module controls the heat dissipation fan to operate at multiple different preset speeds in sequence, including: the host controller sends a control signal to the voltage output module; the voltage output module provides a voltage signal to the heat dissipation fan according to the control signal, and the voltage signal is used to drive the heat dissipation fan to operate; the counter module detects the fan speed during the operation of the heat dissipation fan and sends the fan speed to the host controller; the host controller calculates the speed deviation between the fan speed and the preset speed; the host controller determines the voltage compensation value according to the speed deviation; the host controller adjusts the control signal sent to the voltage output module according to the voltage compensation value, and then adjusts the voltage signal provided by the voltage output module to the heat dissipation fan, and the adjusted voltage signal is used to adjust the fan speed during the operation of the heat dissipation fan to the preset speed. In this way, the closed-loop control method of the fan speed of the heat dissipation fan using the host controller, the voltage output module and the counter module can realize the precision control of the fan speed of the heat dissipation fan, thereby improving the stability of the abnormal sound detection of the heat dissipation fan.

In one possible implementation, at least one recording element includes a first recording element and a second recording element, and the first recording element and the second recording element are respectively located on opposite sides of the test base plate; the multiple different preset rotation speeds include a first preset rotation speed and a second preset rotation speed, the first preset rotation speed is 4000±50rpm, and the second preset rotation speed is 2500±50rpm; the multiple different rotation angles include a first rotation angle, a second rotation angle and a third rotation angle, the first rotation angle is 0°, the second rotation angle is 90°, and the third rotation angle is 180°.

In the second aspect, the embodiment of the present application proposes a fan abnormal sound detection system, including a sound source collection device and an abnormal sound detection module, the sound source collection device includes a driving mechanism, a test base plate, at least one recording element and a fan control module, the driving mechanism is respectively connected to the test base plate and the at least one recording element, a cooling fan is fixed on the test base plate, the fan control module is electrically connected to the cooling fan, and the at least one recording element is electrically connected to the abnormal sound detection module. The fan control module is used to control the cooling fan to operate at a plurality of different preset speeds in sequence; the driving mechanism is used to drive the cooling fan and the at least one recording element on the test base plate to rotate synchronously to a plurality of different rotation angles when the cooling fan operates at each preset speed; the at least one recording element is used to collect the sound source signal of the cooling fan once when the cooling fan operates at each preset speed and the cooling fan and the at least one recording element rotate synchronously to each rotation angle; the at least one recording element is also used to send each collected sound source signal to the abnormal sound detection module; the abnormal sound detection module is used to detect whether there is abnormal sound in the cooling fan according to each sound source signal.

In one possible implementation, the abnormal sound detection module is specifically used to: calculate the average spectral kurtosis and the average spectral peak of each sound source signal; calculate the sound pressure level of each sound source signal; and determine whether the cooling fan has abnormal sound based on the average spectral kurtosis, the average spectral peak and the sound pressure level of each sound source signal.

In one possible implementation, the abnormal sound detection module is specifically used to: perform bandpass filtering on each sound source signal; perform Fourier transform on each sound source signal after the bandpass filtering to obtain the frequency spectrum corresponding to each sound source signal; extract the frequency band to be analyzed in the frequency spectrum corresponding to each sound source signal; and calculate the average frequency spectrum kurtosis and average frequency spectrum peak of each sound source signal based on the frequency band to be analyzed corresponding to each sound source signal.

In a possible implementation, the frequency band to be analyzed includes multiple octave frequency bands corresponding to the rotation frequency of the cooling fan. The abnormal sound detection module is specifically used to: calculate the spectrum kurtosis and spectrum peak corresponding to each octave frequency band included in the frequency band to be analyzed corresponding to each sound source signal; calculate the average value of the spectrum kurtosis corresponding to the multiple octave frequency bands included in the frequency band to be analyzed corresponding to each sound source signal, and obtain the average spectrum kurtosis of each sound source signal; calculate the average value of the spectrum peaks corresponding to the multiple octave frequency bands included in the frequency band to be analyzed corresponding to each sound source signal, and obtain the average spectrum peak of each sound source signal.

In a possible implementation, the abnormal sound detection module is specifically used to: perform high-pass filtering on each sound source signal; filter each sound source signal after the high-pass filtering using a human ear hearing model; and calculate the sound pressure level of each sound source signal after the filtering using the human ear hearing model.

In a possible implementation, the abnormal sound detection module is specifically used to: calculate the product of the sampling value corresponding to each sound source signal after filtering using the human ear auditory model and the reference voltage of the analog-to-digital conversion to obtain the voltage value corresponding to each sound source signal; calculate the ratio of the voltage value corresponding to each sound source signal to the sensitivity of the recording element to obtain the sound pressure of each sound source signal; calculate the sound pressure level of each sound source signal by the following formula: SPL=20×lg(P _e /P _ref ); wherein SPL represents the sound pressure level of each sound source signal, P _e represents the sound pressure of each sound source signal, and _Pref represents the reference sound pressure.

In one possible implementation, the abnormal sound detection module is specifically used to: determine that there is no abnormal sound in the cooling fan when the average spectral kurtosis of each sound source signal is less than the spectral kurtosis threshold, the average spectral peak of each sound source signal is less than the spectral peak threshold, and the sound pressure level of each sound source signal is less than the sound pressure level threshold; determine that there is abnormal sound in the cooling fan when the average spectral kurtosis of at least one sound source signal is greater than or equal to the spectral kurtosis threshold, and/or the average spectral peak of at least one sound source signal is greater than or equal to the spectral peak threshold, and/or the sound pressure level of at least one sound source signal is greater than or equal to the sound pressure level threshold.

In a possible implementation, the fan control module includes a host controller, a voltage output module and a counter module, the host controller is electrically connected to the voltage output module and the counter module respectively, and the voltage output module and the counter module are also electrically connected to the cooling fan. The host controller is used to send a control signal to the voltage output module; the voltage output module is used to provide a voltage signal to the cooling fan according to the control signal, and the voltage signal is used to drive the cooling fan to operate; the counter module is used to detect the fan speed during the operation of the cooling fan and send the fan speed to the host controller; the host controller is also used to calculate the speed deviation between the fan speed and the preset speed; the host controller is also used to determine the voltage compensation value according to the speed deviation; the host controller is also used to adjust the control signal sent to the voltage output module according to the voltage compensation value, and then adjust the voltage signal provided by the voltage output module to the cooling fan, and the adjusted voltage signal is used to adjust the fan speed during the operation of the cooling fan to the preset speed.

In one possible implementation, at least one recording element includes a first recording element and a second recording element, and the first recording element and the second recording element are respectively located on opposite sides of the test base plate; the multiple different preset rotation speeds include a first preset rotation speed and a second preset rotation speed, the first preset rotation speed is 4000±50rpm, and the second preset rotation speed is 2500±50rpm; the multiple different rotation angles include a first rotation angle, a second rotation angle and a third rotation angle, the first rotation angle is 0°, the second rotation angle is 90°, and the third rotation angle is 180°.

The possible implementation methods of the second aspect have effects similar to those of the first aspect and possible designs of the first aspect, and will not be elaborated here.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic structural diagram of a fan abnormal noise detection system provided in an embodiment of the present application;

FIG2 is a schematic diagram of the structure of a sound source acquisition device provided in an embodiment of the present application;

FIG3 is a schematic diagram of the three-dimensional structure of the sound source collection device provided in an embodiment of the present application from one viewing angle;

FIG4 is a partial enlarged view of the fixed bracket and the test base plate in the sound source acquisition device provided in an embodiment of the present application;

FIG5 is a schematic diagram of the structure of a fan control module provided by the related art;

FIG6 is a schematic diagram of the structure of a fan control module provided in an embodiment of the present application;

FIG7 is a flow chart of a method for detecting abnormal fan noise provided by an embodiment of the present application;

FIG8 is a flow chart of using a recording element to collect a sound source signal of a cooling fan according to an embodiment of the present application;

FIG. 9 is a flow chart of an abnormal sound detection module in an embodiment of the present application detecting whether there is abnormal sound from a cooling fan according to a sound source signal.

DETAILED DESCRIPTION

In order to facilitate the clear description of the technical solutions of the embodiments of the present application, in the embodiments of the present application, the words "first", "second" and the like are used to distinguish the same items or similar items with substantially the same functions and effects. For example, the first chip and the second chip are only used to distinguish different chips, and their order is not limited. Those skilled in the art can understand that the words "first", "second" and the like do not limit the quantity and execution order, and the words "first", "second" and the like do not necessarily limit them to be different.

It should be noted that in the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

In the embodiments of the present application, "at least one" refers to one or more, and "more than one" refers to two or more. "And/or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and/or B can represent: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character "/" generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, a-b, a-c, b-c, or a-b-c, where a, b, c can be single or multiple.

With the continuous development of electronic technology, electronic devices such as laptops have gradually become more commonly used tools in people's lives and work. During the operation of electronic devices such as laptops, the devices installed inside them (such as processors, etc.) will generate a certain amount of heat, especially when running under high load scenarios, they may generate a lot of heat. If this heat cannot be discharged to the outside air in time, it may cause the performance of devices such as processors to decline, and in severe cases, it may even cause damage to devices such as processors or reduce their service life.

Therefore, in order to discharge the heat generated by the electronic device to the outside air in time, some electronic devices may be provided with a heat dissipation fan for heat dissipation. In this way, the rotation of the heat dissipation fan increases the speed of air flow, so that the heat generated by the electronic device is discharged to the outside air faster.

However, there may be some defects in the processing and assembly of cooling fans. If these defective cooling fans are installed in electronic devices, the defective cooling fans will also operate during the operation of the electronic devices, which may cause these defective cooling fans to produce abnormal noise during operation, thus giving consumers a bad intuitive feeling. Therefore, before installing the cooling fans in electronic devices, it is necessary to detect abnormal noises on the cooling fans to intercept the cooling fans with abnormal noises and select the cooling fans without abnormal noises.

In some related technologies, a manual detection method can be used to detect abnormal noise of the cooling fan. Specifically, the detection personnel hold the cooling fan in operation and place it next to the detection personnel's ear, and the detection personnel listens to the sound of the cooling fan in operation to determine whether the cooling fan has abnormal noise.

However, this manual detection method will cause auditory fatigue when the inspector listens to the sound of the cooling fan for a long time, which will affect the inspector's subjective judgment of the abnormal sound detection result of the cooling fan, and the detection will also be affected by environmental noise, that is, the manual detection method is greatly affected by environmental noise and subjective factors of the inspector, thereby affecting the accuracy of the abnormal sound detection result of the cooling fan. In addition, the manual detection method also has the problem of low detection efficiency.

In other related technologies, the cooling fan can be placed in a soundproof box, and a recording element can be set in the soundproof box to collect sound source signals. During the abnormal sound detection process of the cooling fan, the cooling fan can be controlled to rotate to different rotation angles, and the recording element collects the sound source signals when the cooling fan is running at different rotation angles. The software system analyzes the sound source signals of the cooling fan to detect whether the cooling fan has abnormal sounds.

However, in this detection method, the cooling fan is running at a single speed, and the abnormal sound of the cooling fan may not be stimulated at a single speed, resulting in the cooling fan with abnormal sound, which may not be detected during the detection process, thus affecting the accuracy of the abnormal sound detection result of the cooling fan. In addition, in this detection method, the recording element is set at a fixed position in the soundproof box. Therefore, when the cooling fan rotates to different rotation angles, the angle and relative position between the cooling fan and the recording element will change, which will affect the consistency of the sound source signal collected by the recording element, and further affect the accuracy of the abnormal sound detection result of the cooling fan.

Based on this, an embodiment of the present application provides a fan abnormal sound detection method and a fan abnormal sound detection system. The fan control module controls the cooling fan to operate at multiple different preset speeds in sequence. When the cooling fan operates at each preset speed, the driving mechanism drives the cooling fan and at least one recording element on the test base plate to rotate synchronously to multiple different rotation angles. When the cooling fan operates at each preset speed and the cooling fan and at least one recording element rotate synchronously to each rotation angle, at least one recording element collects the sound source signal of the cooling fan once and sends it to the abnormal sound detection module. The abnormal sound detection module detects whether there is abnormal sound in the cooling fan based on each sound source signal.

In this way, compared with the manual detection method, the embodiment of the present application uses a recording element to collect the sound source signal during the operation of the cooling fan, and analyzes the sound source signal through the abnormal sound detection module to automatically detect whether there is an abnormal sound in the cooling fan. During the detection process, it is less affected by the environmental noise and the subjective factors of the detection personnel, thereby improving the accuracy of the abnormal sound detection results of the cooling fan and improving the efficiency of the abnormal sound detection of the cooling fan.

Furthermore, compared with using a recording element fixedly arranged in a soundproof box to collect the sound source signal of the cooling fan when it is running at different rotation angles to detect the abnormal sound of the cooling fan, the embodiment of the present application uses a recording element to collect the sound source signal of the cooling fan when the cooling fan is at multiple different preset speeds and multiple different rotation angles. The cooling fan runs at multiple different preset speeds, which can increase the possibility that the cooling fan with abnormal sound is stimulated to produce abnormal sound during the detection process, thereby improving the accuracy of the abnormal sound detection result of the cooling fan. Furthermore, when the cooling fan rotates to multiple different rotation angles, the recording element and the cooling fan rotate synchronously, so that when the cooling fan rotates to different rotation angles, the angle and relative position between the cooling fan and the recording element will not change, which can improve the consistency of the sound source signal collected by the recording element at different rotation angles of the cooling fan, thereby improving the accuracy of the abnormal sound detection result of the cooling fan.

It can be understood that the cooling fan in the embodiment of the present application can be a cooling fan to be installed in a laptop computer. Of course, the cooling fan in the embodiment of the present application can also be a cooling fan in other electronic devices, such as a cooling fan in a desktop computer, etc. The embodiment of the present application does not limit the specific device form of the electronic device to which the cooling fan is applied.

In order to better understand the embodiments of the present application, the fan abnormal sound detection method and the fan abnormal sound detection system of the embodiments of the present application are introduced in detail below. The fan abnormal sound detection method can be applied to the fan abnormal sound detection system.

Exemplarily, FIG1 is a schematic diagram of the structure of a fan abnormal sound detection system provided in an embodiment of the present application. Referring to FIG1 , the fan abnormal sound detection system includes a sound source acquisition device 110 and an abnormal sound detection module 120. The sound source acquisition device 110 includes a driving mechanism 111, a test base plate 112, at least one recording element 113 and a fan control module 114, the driving mechanism 111 is respectively connected to the test base plate 112 and at least one recording element 113, a cooling fan 200 is fixed on the test base plate 112, the fan control module 114 is electrically connected to the cooling fan 200, and at least one recording element 113 is electrically connected to the abnormal sound detection module 120.

Among them, the fan control module 114 is used to control the cooling fan 200 to operate at a plurality of different preset speeds in sequence. The driving mechanism 111 is used to drive the cooling fan 200 and at least one recording element 113 on the test base plate 112 to rotate synchronously to a plurality of different rotation angles when the cooling fan 200 operates at each preset speed. At least one recording element 113 is used to collect the sound source signal of the cooling fan 200 once when the cooling fan 200 operates at each preset speed and the cooling fan 200 and at least one recording element 113 rotate synchronously to each rotation angle; at least one recording element 113 is also used to send each collected sound source signal to the abnormal sound detection module 120. The abnormal sound detection module 120 is used to detect whether there is abnormal sound in the cooling fan 200 according to each sound source signal.

In some embodiments, the number of the recording element 113 in the sound source collection device 110 is at least one, that is, the number of the recording elements 113 in the sound source collection device 110 can be 1, 2, or 3. The embodiment of the present application does not limit the number of the recording elements 113 in the sound source collection device 110, and it can be set according to actual conditions.

When the number of recording elements 113 in the sound source collection device 110 is greater, more sound source signals are collected during the abnormal sound detection of the cooling fan 200, which can further increase the possibility of collecting the abnormal sound of the cooling fan 200 during the detection process, thereby further improving the accuracy of the abnormal sound detection result of the cooling fan 200.

Taking the number of recording elements 113 in the sound source collection device 110 as two, as shown in FIG2 , at least one recording element 113 in the sound source collection device 110 includes a first recording element 1131 and a second recording element 1132, that is, the two recording elements 113 in the sound source collection device 110 can be respectively referred to as the first recording element 1131 and the second recording element 1132. The first recording element 1131 can also be referred to as an upper recording standard microphone, and the second recording element 1132 can be referred to as a lower recording standard microphone.

The driving mechanism 111 is mechanically connected to the first recording element 1131 and the second recording element 1132 respectively, and the driving mechanism 111 is also mechanically connected to the test base plate 112 (not shown in FIG. 2 ). When performing abnormal sound detection on the cooling fan 200, the cooling fan 200 can be fixed on the test base plate 112, and the driving mechanism 111 can drive the test base plate 112, the first recording element 1131 and the second recording element 1132 to rotate synchronously in the direction of the arrow shown in FIG. 2 , so that the cooling fan 200, the first recording element 1131 and the second recording element 1132 on the test base plate 112 rotate synchronously to a preset rotation angle.

As shown in FIG3 , the driving mechanism 111 may include a servo motor 1111 and a rotating arm 1112. The servo motor 1111 may be a silent direct drive motor. The servo motor 1111 is mechanically connected to the rotating arm 1112, and the rotating arm 1112 is mechanically connected to the test base plate 112, the first recording element 1131, and the second recording element 1132. The first recording element 1131 and the second recording element 1132 are respectively located on opposite sides of the test base plate 112.

When the abnormal sound detection is performed on the cooling fan 200, the servo motor 1111 drives the rotating arm 1112 to rotate. Since the rotating arm 1112 is also mechanically connected to the test base plate 112, the first recording element 1131 and the second recording element 1132 respectively, when the rotating arm 1112 rotates, it will drive the test base plate 112, the first recording element 1131 and the second recording element 1132 to rotate synchronously, that is, the test base plate 112, the first recording element 1131 and the second recording element 1132 will rotate synchronously with the rotating arm 1112, so that the cooling fan 200, the first recording element 1131 and the second recording element 1132 on the test base plate 112 rotate synchronously to a preset rotation angle.

In order to detect abnormal sounds of the cooling fan 200 at multiple rotation angles, the embodiment of the present application can use the servo motor 1111 and the rotating arm 1112 as shown in Figure 3 to control the rotation of the cooling fan 200, thereby realizing stepless angle control of the cooling fan 200, that is, controlling the cooling fan 200 to rotate at any angle between 0° and 360°.

When the abnormal sound detection is performed on the cooling fan 200, as shown in FIG3 and FIG4, the cooling fan 200 is set on the test base plate 112, and the cooling fan 200 is fixed on the test base plate 112 by the fixing bracket 115. In some embodiments, there can be multiple fixing brackets 115 in the sound source collection device 110. In the process of performing abnormal sound detection on the cooling fan 200, the fixing bracket 115 can be controlled by a motor to fix the cooling fan 200 on the test base plate 112. The motor used to drive the fixing bracket 115 is not the same motor as the servo motor 1111 used to drive the rotating arm 1112 to rotate.

After the cooling fan 200 is fixed on the test base plate 112, the first recording element 1131 and the second recording element 1132 are both arranged perpendicular to the cooling fan 200. Furthermore, when the servo motor 1111 and the rotating arm 1112 are used to control the cooling fan 200, the first recording element 1131 and the second recording element 1132 to rotate synchronously, the angle and relative position between the first recording element 1131 and the cooling fan 200 do not change, and the angle and relative position between the second recording element 1132 and the cooling fan 200 do not change.

In addition, the sound source collection device 110 further includes a support member 116 , a support bearing 117 and other auxiliary structures. The support member 116 and the support bearing 117 are used to be fixed to the base of the sound source collection device 110 .

In some scenarios, the cooling fan 200 may produce abnormal noise only in certain placement postures or speed states. Therefore, in order to increase the possibility that the cooling fan with abnormal noise will be stimulated to produce abnormal noise during the detection process, the embodiment of the present application can collect the sound source signal of the cooling fan 200 when it is running in different postures and different speed states.

That is to say, when the fan control module 114 controls the cooling fan 200 to operate at each of a plurality of different preset speeds, and the driving mechanism 111 drives the cooling fan 200, the first recording element 1131 and the second recording element 1132 to rotate synchronously to each of a plurality of different rotation angles, the first recording element 1131 and the second recording element 1132 both collect the sound source signal of the cooling fan 200 once.

In some embodiments, the plurality of different preset speeds include a first preset speed and a second preset speed, the first preset speed is greater than the second preset speed, the first preset speed can be called a medium speed, and the second preset speed can be called a low speed. For example, the first preset speed is 4000±50rpm, and the second preset speed is 2500±50rpm.

It is understandable that the first preset speed is not limited to 4000±50 rpm, and the second preset speed is not limited to 2500±50 rpm. The embodiment of the present application does not limit the specific values of the first preset speed and the second preset speed.

The fan control module 114 uses the voltage signal to control the cooling fan 200 to perform stepless speed regulation, so as to adjust the fan speed of the cooling fan 200 to the first preset speed and the second preset speed respectively. Stepless speed regulation refers to the regulation of any speed, that is, the cooling fan 200 can achieve any continuous speed change under the control of the fan control module 114.

In some embodiments, the plurality of different rotation angles include a first rotation angle, a second rotation angle, and a third rotation angle, and the first rotation angle, the second rotation angle, and the third rotation angle are different from each other. For example, the first rotation angle is 0°, the second rotation angle is 90°, and the third rotation angle is 180°.

It can be understood that the first rotation angle is not limited to 0°, the second rotation angle is not limited to 90°, and the third rotation angle is not limited to 180°. The embodiment of the present application does not limit the specific values of the first rotation angle, the second rotation angle, and the third rotation angle.

The driving mechanism 111 can control the cooling fan 200 to hover at three positions, namely, the first rotation angle, the second rotation angle, and the third rotation angle. For example, when the cooling fan 200 is hovering in the horizontal direction shown in FIG. 3 , and the first recording element 1131 is located above the test base plate 112, and the second recording element 1132 is located below the test base plate 112, the rotation angle of the cooling fan 200 is the first rotation angle of 0°; when the cooling fan 200 is hovering in the vertical direction, the rotation angle of the cooling fan 200 is the second rotation angle of 90°; when the cooling fan 200 is hovering in the horizontal direction, and the first recording element 1131 is located below the test base plate 112, and the second recording element 1132 is located above the test base plate 112, the rotation angle of the cooling fan 200 is the third rotation angle of 180°.

The following takes multiple different preset rotation speeds including a first preset rotation speed and a second preset rotation speed, and multiple different rotation angles including a first rotation angle, a second rotation angle, and a third rotation angle as an example to illustrate the specific process of collecting sound source signals for the cooling fan 200 in an embodiment of the present application.

When performing abnormal sound detection on the cooling fan 200 , the fan control module 114 first adjusts the fan speed of the cooling fan 200 to a first preset speed. When the fan speed of the cooling fan 200 is adjusted to the first preset speed, the driving mechanism 111 first drives the cooling fan 200, the first recording element 1131 and the second recording element 1132 on the test base plate 112 to rotate synchronously to the first rotation angle, at which time the first recording element 1131 and the second recording element 1132 respectively collect the sound source signal of the cooling fan 200 once; the driving mechanism 111 then drives the cooling fan 200, the first recording element 1131 and the second recording element 1132 on the test base plate 112 to rotate synchronously to the second rotation angle, at which time the first recording element 1131 and the second recording element 1132 respectively collect the sound source signal of the cooling fan 200 once; the driving mechanism 111 continues to drive the cooling fan 200, the first recording element 1131 and the second recording element 1132 on the test base plate 112 to rotate synchronously to the third rotation angle, at which time the first recording element 1131 and the second recording element 1132 respectively collect the sound source signal of the cooling fan 200 once.

Then, the fan control module 114 adjusts the fan speed of the heat dissipation fan 200 to a second preset speed. When the fan speed of the cooling fan 200 is adjusted to the second preset speed, the driving mechanism 111 first drives the cooling fan 200, the first recording element 1131 and the second recording element 1132 on the test base plate 112 to rotate synchronously to the first rotation angle, at which time the first recording element 1131 and the second recording element 1132 respectively collect the sound source signal of the cooling fan 200 once; the driving mechanism 111 then drives the cooling fan 200, the first recording element 1131 and the second recording element 1132 on the test base plate 112 to rotate synchronously to the second rotation angle, at which time the first recording element 1131 and the second recording element 1132 respectively collect the sound source signal of the cooling fan 200 once; the driving mechanism 111 continues to drive the cooling fan 200, the first recording element 1131 and the second recording element 1132 on the test base plate 112 to rotate synchronously to the third rotation angle, at which time the first recording element 1131 and the second recording element 1132 respectively collect the sound source signal of the cooling fan 200 once.

In summary, the embodiment of the present application uses the first recording element 1131 and the second recording element 1132 to respectively collect the sound source signals of the cooling fan 200 at the first rotation angle, the second rotation angle and the third rotation angle at the first preset speed, and respectively collect the sound source signals of the cooling fan 200 at the first rotation angle, the second rotation angle and the third rotation angle at the second preset speed. In other words, the first recording element 1131 collects a total of 6 sound source signals, and the second recording element 1132 also collects a total of 6 sound source signals, that is, a total of 12 sound source signals are collected for the cooling fan 200. These 12 sound source signals can be sent to the abnormal sound detection module 120, and the abnormal sound detection module 120 can detect whether there is an abnormal sound in the cooling fan 200 based on these 12 sound source signals.

It is understandable that the multiple different preset speeds in the embodiment of the present application are not limited to two preset speeds, and can also be other numbers of preset speeds, such as the multiple different preset speeds are three different preset speeds, that is, the multiple different preset speeds include a first preset speed, a second preset speed, and a third preset speed, and the first preset speed, the second preset speed, and the third preset speed are all different. The embodiment of the present application does not limit the number of preset speeds, and it can be set according to actual conditions.

Accordingly, the multiple different rotation angles in the embodiment of the present application are not limited to three rotation angles, and can also be other numbers of rotation angles, such as the multiple different rotation angles are four different rotation angles, that is, the multiple different rotation angles can include a first rotation angle, a second rotation angle, a third rotation angle, and a fourth rotation angle, and the first rotation angle, the second rotation angle, the third rotation angle, and the fourth rotation angle are all different. The embodiment of the present application does not limit the number of rotation angles, and it can be set according to actual conditions.

Therefore, the embodiment of the present application uses a recording element 113 to collect the sound source signal of the cooling fan 200 at multiple different preset rotation speeds and multiple different rotation angles, and uses the abnormal sound detection module 120 to detect whether the cooling fan 200 has abnormal sounds based on the collected multiple sound source signals. This can increase the possibility that the cooling fan 200 with abnormal sounds will be stimulated to produce abnormal sounds during the detection process, thereby improving the accuracy of the abnormal sound detection results of the cooling fan 200.

Furthermore, when the cooling fan 200 rotates to a plurality of different rotation angles, the angle and relative position between the cooling fan 200 and the recording element 113 will not change, which can improve the consistency of the sound source signal collected by the recording element 113 at different rotation angles of the cooling fan 200, thereby improving the accuracy of the abnormal sound detection result of the cooling fan 200.

In some related technologies, as shown in Fig. 5, the fan control module 114 may include a host controller 1141 and a voltage output module 1142. The host controller 1141 may send a control signal to the voltage output module 1142, and the voltage output module 1142 may provide a voltage signal to the cooling fan 200 according to the control signal, and the voltage signal is used to drive the cooling fan 200 to operate.

However, when the related technology adopts the above-mentioned open-loop control method to control the cooling fan 200 to switch between the first preset speed and the second preset speed, due to the characteristic deviation of the voltage-speed curve of some cooling fans 200, and due to the possible scratching, yaw, vibration and other problems in the structure of the cooling fan 200, the actual speed deviation of different cooling fans 200 is large under the same voltage. The speed deviation of different cooling fans 200 will cause the abnormal sound of the cooling fan 200 to be inconsistent, thereby affecting the abnormal sound detection result of the cooling fan 200.

In order to achieve accurate control of the fan speed of the cooling fan 200, a counter module is added to the fan control module 114 to achieve closed-loop control of the fan speed of the cooling fan 200. As shown in FIG6, the fan control module 114 includes an upper controller 1141, a voltage output module 1142 and a counter module 1143, and the upper controller 1141 is electrically connected to the voltage output module 1142 and the counter module 1143 respectively, and the voltage output module 1142 and the counter module 1143 are also electrically connected to the cooling fan 200.

Among them, the upper controller 1141 is used to send a control signal to the voltage output module 1142; the voltage output module 1142 is used to provide a voltage signal to the cooling fan 200 according to the control signal, and the voltage signal is used to drive the cooling fan 200 to operate; the counter module 1143 is used to detect the fan speed of the cooling fan 200 during operation, and send the fan speed to the upper controller 1141; the upper controller 1141 is also used to calculate the speed deviation between the fan speed and the preset speed; the upper controller 1141 is also used to determine the voltage compensation value according to the speed deviation; the upper controller 1141 is also used to adjust the control signal sent to the voltage output module 1142 according to the voltage compensation value, and then adjust the voltage signal provided by the voltage output module 1142 to the cooling fan 200, and the adjusted voltage signal is used to adjust the fan speed of the cooling fan 200 during operation to the preset speed.

When the upper controller 1141 sends a control signal to the voltage output module 1142, and the voltage output module 1142 provides a voltage signal to the cooling fan 200 according to the control signal to drive the cooling fan 200 to operate, the counter module 1143 can detect the fan speed of the cooling fan 200 during operation in real time, and send the detected fan speed to the upper controller 1141.

Specifically, when the cooling fan 200 rotates, the counter module 1143 detects the frequency square wave signal generated by the cooling fan 200 every time it rotates. The counter module 1143 counts the number of frequency square wave signals within a preset period and calculates the rotation frequency of the cooling fan 200. The counter module 1143 converts the fan speed of the cooling fan 200 during operation according to the corresponding relationship between the rotation frequency of the cooling fan 200 and the fan speed. Among them, the rotation frequency of the cooling fan 200 is proportional to the fan speed.

The upper controller 1141 compares the fan speed with the preset speed, calculates the difference between the fan speed and the preset speed, and obtains the speed deviation. For example, when the upper controller 1141 and the voltage output module 1142 control the cooling fan 200 to adjust from the first preset speed to the second preset speed, the upper controller 1141 compares the fan speed collected by the counter module 1143 with the second preset speed, and calculates the speed deviation between the fan speed and the second preset speed.

Next, the upper controller 1141 determines the voltage compensation value corresponding to the speed deviation based on the voltage-speed curve of the standard cooling fan. The voltage compensation value can also be called voltage interpolation, which is used to compensate the voltage signal provided to the cooling fan 200 through the voltage output module 1142, so that the actual fan speed of the cooling fan 200 can reach the preset speed range, thereby controlling the abnormal sound variable of the cooling fan 200.

For example, if the voltage value of the voltage signal corresponding to the preset speed of 4000rpm is 5V, the upper controller 1141 provides a 5V voltage signal to the cooling fan 200 through the voltage output module 1142. At this time, the counter module 1143 collects the actual fan speed of the cooling fan 200 as 3900rpm, and the upper controller 1141 calculates that the speed deviation is 100rpm. The upper controller 1141 determines that the voltage compensation value corresponding to the speed deviation of 100rpm is 0.1V, and the upper controller 1141 compensates the voltage signal of the cooling fan 200 through the voltage output module 1142, that is, provides a 5.1V voltage signal to the cooling fan 200 through the voltage output module 1142 to adjust the actual fan speed of the cooling fan 200 to 4000rpm.

After testing, by adopting the method of performing open-loop control on the fan speed of the cooling fan 200 as shown in FIG5, the speed deviation of the cooling fan 200 can reach ±300rpm, while by adopting the method of performing closed-loop control on the fan speed of the cooling fan 200 as shown in FIG6, the speed deviation of the cooling fan 200 can be reduced to 50rpm. Therefore, the embodiment of the present application adopts the method of performing closed-loop control on the fan speed of the cooling fan 200 as shown in FIG6, which can achieve precision control of the fan speed of the cooling fan 200, thereby improving the stability of abnormal sound detection of the cooling fan 200.

It should be noted that the upper controller 1141 in the fan control module 114 and the abnormal sound detection module 120 may be integrated together or independently provided.

In an embodiment of the present application, the abnormal sound detection module 120 may be a host computer, and the abnormal sound detection module 120 is specifically used to: calculate the average spectral kurtosis and the average spectral peak of each sound source signal; calculate the sound pressure level of each sound source signal; and determine whether the cooling fan 200 has abnormal sound based on the average spectral kurtosis, the average spectral peak and the sound pressure level of each sound source signal.

The source of abnormal sound of the cooling fan 200 may be an unbalanced rotor, uneven blade quality, periodic friction between the blade and the outer frame structure, and loosening caused by uneven winding of the motor winding. In some related technologies, only the abnormal sound itself is focused on, and the sound pressure level of certain frequency bands in the collected sound source signal is used to determine whether there is abnormal sound in the cooling fan 200. However, this method is easily affected by equipment noise, environmental noise, fan speed, etc., especially the low-frequency noise interference is more, which makes the sound pressure level have a poor effect on intercepting low-frequency abnormal sound, resulting in the interception rate and over-kill rate of the abnormal sound detection of the cooling fan 200 are difficult to meet the requirements, resulting in the problem of low accuracy of the abnormal sound detection result of the cooling fan 200 when only the sound pressure level is used to determine whether there is abnormal sound in the cooling fan 200.

Therefore, the embodiment of the present application not only takes into account the corresponding sound pressure level of the sound source signal of the cooling fan 200, but also focuses on a specific frequency band and introduces the average spectrum kurtosis and the average spectrum peak. That is, the average spectrum kurtosis, the average spectrum peak and the sound pressure level are used to jointly determine whether there is an abnormal sound in the cooling fan 200, thereby improving the interception rate of the abnormal sound detection of the cooling fan 200 and reducing the over-kill rate of the abnormal sound detection of the cooling fan 200, thereby further improving the accuracy of the abnormal sound detection result of the cooling fan 200.

In some embodiments, the abnormal sound detection module 120 is specifically used to: perform bandpass filtering on each sound source signal; perform Fourier transform on each sound source signal after bandpass filtering to obtain the frequency spectrum corresponding to each sound source signal; extract the frequency band to be analyzed in the frequency spectrum corresponding to each sound source signal; and calculate the average spectral kurtosis and average spectral peak of each sound source signal based on the frequency band to be analyzed corresponding to each sound source signal.

Specifically, the frequency band to be analyzed includes multiple octave frequency bands corresponding to the rotation frequency of the cooling fan 200. The abnormal sound detection module 120 is specifically used to: calculate the spectrum kurtosis and spectrum peak corresponding to each octave frequency band included in the frequency band to be analyzed corresponding to each sound source signal; calculate the average value of the spectrum kurtosis corresponding to the multiple octave frequency bands included in the frequency band to be analyzed corresponding to each sound source signal, and obtain the average spectrum kurtosis of each sound source signal; calculate the average value of the spectrum peaks corresponding to the multiple octave frequency bands included in the frequency band to be analyzed corresponding to each sound source signal, and obtain the average spectrum peak of each sound source signal.

Each sound source signal collected by the recording element 113 is a time domain waveform. After each sound source signal is subjected to bandpass filtering, each sound source signal after bandpass filtering is also a time domain waveform. Then, Fourier transform can be used to transform each sound source signal after bandpass filtering into the frequency domain to obtain the spectrum corresponding to each sound source signal.

Since the cooling fan 200 is a rotating mechanical structure, the characteristic frequency of most faults is the rotation frequency. The characteristic frequency of the fault can also be represented by the period of the fault. The rotation frequency refers to the rotation frequency, that is, the rotation frequency of the cooling fan 200 when it rotates.

If the fault of the cooling fan 200 is a single point contact, the fault waveform is a sine wave with a frequency of the rotation frequency; if the fault is a line or surface contact, the fault waveform is a superposition of waveforms with the same frequency (rotation frequency), different amplitudes, and different phases, thereby generating waveform distortion. The greater the degree of the fault, the greater the degree of waveform distortion. If the cooling fan 200 is not faulty, the frequency spectrum of its corresponding sound source signal after Fourier transformation does not contain the frequency multiplication component of the rotation frequency. If the cooling fan 200 is faulty, the waveform corresponding to the rotation frequency will be distorted after the Fourier transformation of its corresponding sound source signal, and its frequency multiplication component needs to be synthesized, so that the prominent frequency of the spectrum will produce many frequency multiplication components of the rotation frequency in addition to the rotation frequency.

Therefore, in the low frequency band, some octave frequency bands of the rotation frequency are used as the frequency bands to be analyzed, that is, the frequency bands to be analyzed include multiple octave frequency bands corresponding to the rotation frequency of the cooling fan 200. For each sound source signal corresponding to the frequency band to be analyzed, the spectral kurtosis and spectral peak corresponding to each octave frequency band included therein are calculated; then, the spectral kurtosis corresponding to multiple octave frequency bands in the frequency band to be analyzed of each sound source signal is averaged to obtain the average spectral kurtosis of each sound source signal, and the spectral peaks corresponding to multiple octave frequency bands in the frequency band to be analyzed of each sound source signal are averaged to obtain the average spectral peak of each sound source signal. The average spectral kurtosis and the average spectral peak are used as part of the detection indicators for judging whether there is abnormal sound in the cooling fan 200.

The spectral kurtosis corresponding to the octave band refers to the steepness of the octave band, which is defined as: the fourth-order central moment of the random variable divided by the fourth power of the standard deviation. It is a dimensionless factor used to test the degree to which the signal deviates from the normal distribution.

It should be noted that the spectrum corresponding to each sound source signal includes many frequency bands, such as the frequency bands from 1x to 30x of the frequency conversion. The embodiment of the present application can extract some of the multiple frequency bands from the spectrum corresponding to the sound source signal as the frequency band to be analyzed. The embodiment of the present application does not limit the specific range of the multiple frequency bands included in the frequency band to be analyzed.

Taking the example that the frequency band to be analyzed of each sound source signal includes N octave frequency bands, after calculating the spectral kurtosis and spectral peak corresponding to each of the N octave frequency bands, the spectral kurtosis corresponding to the N octave frequency bands is averaged to obtain the average spectral kurtosis, and the spectral peaks corresponding to the N octave frequency bands are averaged to obtain the average spectral peak.

In some embodiments, the abnormal sound detection module 120 is specifically used to: perform high-pass filtering on each sound source signal; filter each sound source signal after high-pass filtering using a human ear auditory model; and calculate the sound pressure level of each sound source signal after filtering using the human ear auditory model.

Since the abnormal sound of some cooling fans 200 is less related to the rotation frequency, but has a large difference with the sound pressure level in the high frequency band, in the high frequency band, after high-pass filtering and human ear hearing model filtering, the sound pressure level of some high frequency bands is calculated as another detection index to determine whether the cooling fan 200 has abnormal sound.

After high-pass filtering is performed on each sound source signal, a human ear hearing model may be used to filter each sound source signal after high-pass filtering, so that the objective index of the sound pressure level finally calculated is consistent with the subjective feeling of the human ear.

For example, the frequency range of high-pass filtering is 10KHz to 24KHz. In this way, the frequency range of each sound source signal after high-pass filtering and human ear auditory model filtering is 10KHz to 24KHz. The embodiment of the present application does not limit the frequency range of high-pass filtering.

Specifically, the abnormal sound detection module 120 is specifically used to: calculate the product of the sampling value corresponding to each sound source signal after filtering using the human ear auditory model and the reference voltage of the analog-to-digital conversion to obtain the voltage value corresponding to each sound source signal; calculate the ratio of the voltage value corresponding to each sound source signal to the sensitivity of the recording element 113 to obtain the sound pressure of each sound source signal; calculate the sound pressure level of each sound source signal by the following formula: SPL=20×lg(P _e /P _ref ); wherein SPL represents the sound pressure level of each sound source signal, P _e represents the sound pressure of each sound source signal, and _Pref represents the reference sound pressure.

In the research fields of hearing test or noise detection, sound pressure level (SPL) is a frequently used indicator. For the convenience of application, sound pressure level is a quantity derived from the characteristics of human ear's response to changes in sound intensity to indicate the size of the sound. The sound pressure level is measured in decibels (dB). The higher the sound pressure level, the louder the sound source signal. The lower the sound pressure level, the smaller the sound source signal.

After high-pass filtering and human hearing model filtering are performed on each sound source signal, each sound source signal is sampled, and the product of the sampled value obtained by sampling and the reference voltage of the analog-to-digital conversion is calculated to obtain the voltage value corresponding to each sound source signal, that is, voltage value = sampling value × reference voltage of analog-to-digital conversion. The unit of the voltage value is volt (V), the unit of the sampling value is Pascal (Pa), and the unit of the reference voltage of the analog-to-digital conversion is V/Pa.

Next, the voltage value corresponding to each sound source signal is divided by the sensitivity of the recording element 113 to obtain the sound pressure of each sound source signal, that is, sound pressure = voltage value / sensitivity. The unit of sensitivity is V/Pa, and the unit of sound pressure is Pa.

Finally, the sound pressure level of each sound source signal is calculated using SPL=20×lg(P _e /P _ref ). That is to say, the sound pressure level is obtained by taking the common logarithm of the ratio of the sound pressure of each sound source signal to the reference sound pressure and then multiplying it by 20.

It should be noted that the reference voltage and reference sound pressure of the analog-to-digital conversion may be preset fixed values. For example, the reference voltage of the analog-to-digital conversion may be 4.88 V/Pa, and the reference sound pressure in air may be 2×10 ^-5 Pa. Sensitivity is a value related to the recording element 113 .

Taking at least one recording element 113 including a first recording element 1131 and a second recording element 1132, a plurality of different preset rotation speeds including a first preset rotation speed and a second preset rotation speed, and a plurality of different rotation angles including a first rotation angle, a second rotation angle and a third rotation angle as an example, a total of 12 sound source signals can be collected, and the above-mentioned method is used for each sound source signal, then the average spectral kurtosis, average spectral peak and sound pressure level of the 12 sound source signals can be calculated.

The abnormal sound detection module 120 is specifically used for: when the average spectral kurtosis of each sound source signal is less than the spectral kurtosis threshold, the average spectral peak of each sound source signal is less than the spectral peak threshold, and the sound pressure level of each sound source signal is less than the sound pressure level threshold, it is determined that there is no abnormal sound in the cooling fan 200; when the average spectral kurtosis of at least one sound source signal is greater than or equal to the spectral kurtosis threshold, and/or the average spectral peak of at least one sound source signal is greater than or equal to the spectral peak threshold, and/or the sound pressure level of at least one sound source signal is greater than or equal to the sound pressure level threshold, it is determined that there is an abnormal sound in the cooling fan 200.

The unusual sound detection module 120 compares the average spectrum kurtosis of each sound source signal with the spectrum kurtosis threshold, compares the average spectrum peak of each sound source signal with the spectrum peak threshold, and compares the sound pressure level of each sound source signal with the sound pressure level threshold.

Taking the collection of 12 sound source signals in total as an example, when the average spectral kurtosis of each of the 12 sound source signals is less than the spectral kurtosis threshold, the average spectral peak of each of the 12 sound source signals is less than the spectral peak threshold, and the sound pressure level of each of the 12 sound source signals is less than the sound pressure level threshold, the abnormal sound detection module 120 determines that there is no abnormal sound in the cooling fan 200.

When the average spectral kurtosis of at least one sound source signal among the 12 sound source signals is greater than or equal to the spectral kurtosis threshold, and/or the average spectral peak value of at least one sound source signal among the 12 sound source signals is greater than or equal to the spectral peak threshold, and/or the sound pressure level of at least one sound source signal among the 12 sound source signals is greater than or equal to the sound pressure level threshold, the abnormal sound detection module 120 determines that the cooling fan 200 has an abnormal sound.

It should be noted that, for the same recording element 113 at the same preset rotation speed, the corresponding spectral kurtosis threshold at different rotation angles is the same, the corresponding spectral peak threshold at different rotation angles is also the same, and the corresponding sound pressure level threshold at different rotation angles is also the same.

Therefore, taking the case of collecting 12 sound source signals in total as an example, there are 4 spectral kurtosis thresholds, which are the spectral kurtosis threshold corresponding to the first recording element 1131 at the first preset rotation speed, the spectral kurtosis threshold corresponding to the first recording element 1131 at the second preset rotation speed, the spectral kurtosis threshold corresponding to the second recording element 1132 at the first preset rotation speed, and the spectral kurtosis threshold corresponding to the second recording element 1132 at the second preset rotation speed. These 4 spectral kurtosis thresholds may not be equal; correspondingly, there are also 4 spectral peak thresholds, which are the spectral peak threshold corresponding to the first recording element 1131 at the first preset rotation speed, the spectral peak threshold corresponding to the first recording element 1131 at the second preset rotation speed, and the spectral peak threshold corresponding to the second recording element 1132 at the second preset rotation speed. The four spectrum peak thresholds may not be equal, namely, the spectrum peak threshold corresponding to the first preset rotation speed of the first recording element 1131, the spectrum peak threshold corresponding to the second recording element 1132 at the first preset rotation speed, and the spectrum peak threshold corresponding to the second recording element 1132 at the second preset rotation speed. Correspondingly, there are four sound pressure level thresholds, namely, the sound pressure level threshold corresponding to the first recording element 1131 at the first preset rotation speed, the sound pressure level threshold corresponding to the first recording element 1131 at the second preset rotation speed, the sound pressure level threshold corresponding to the second recording element 1132 at the first preset rotation speed, and the sound pressure level threshold corresponding to the second recording element 1132 at the second preset rotation speed. These four sound pressure level thresholds may not be equal.

The above describes in detail the abnormal fan noise detection system provided in the embodiment of the present application. Based on the abnormal fan noise detection system shown in FIG1 , the abnormal fan noise detection method provided in the embodiment of the present application is described in detail below. FIG7 is a flow chart of an abnormal fan noise detection method provided in the embodiment of the present application. Referring to FIG7 , the abnormal fan noise detection method may specifically include the following steps:

Step 701: The fan control module controls the cooling fan to operate at a plurality of different preset speeds in sequence.

When performing abnormal sound detection on the cooling fan 200, the cooling fan 200 is first placed in the limit groove of the test base plate 112, and the cooling fan 200 is fixed on the test base plate 112 by using the fixing bracket 115. Then, the test process starts, specifically, the fan control module 114 controls the cooling fan 200 to run at a plurality of different preset speeds in sequence.

The plurality of different preset speeds include a first preset speed and a second preset speed, the first preset speed is 4000±50rpm, and the second preset speed is 2500±50rpm. In other words, the fan control module 114 can first control the cooling fan 200 to rotate at the first preset speed, and then control the cooling fan 200 to operate at the second preset speed.

In some embodiments, the fan control module 114 includes a host controller 1141, a voltage output module 1142 and a counter module 1143. The host controller 1141 is electrically connected to the voltage output module 1142 and the counter module 1143 respectively. The voltage output module 1142 and the counter module 1143 are also electrically connected to the cooling fan 200.

Specifically, the fan control module 114 can control the cooling fan 200 to operate at multiple different preset speeds in sequence in the following manner: the upper controller 1141 sends a control signal to the voltage output module 1142; the voltage output module 1142 provides a voltage signal to the cooling fan 200 according to the control signal, and the voltage signal is used to drive the cooling fan 200 to operate; the counter module 1143 detects the fan speed of the cooling fan 200 during operation, and sends the fan speed to the upper controller 1141; the upper controller 1141 calculates the speed deviation between the fan speed and the preset speed; the upper controller 1141 determines the voltage compensation value according to the speed deviation; the upper controller 1141 adjusts the control signal sent to the voltage output module 1142 according to the voltage compensation value, and then adjusts the voltage signal provided by the voltage output module 1142 to the cooling fan 200, and the adjusted voltage signal is used to adjust the fan speed of the cooling fan 200 during operation to the preset speed.

Taking multiple different preset speeds including a first preset speed and a second preset speed as an example, the upper controller 1141, the voltage output module 1142 and the counter module 1143 can adopt the above-mentioned method to first control the cooling fan 200 to run at the first preset speed, and then control the cooling fan 200 to run at the second preset speed.

Step 702: When the cooling fan is running at each preset speed, the driving mechanism drives the cooling fan and at least one recording element on the test base plate to rotate synchronously to a plurality of different rotation angles.

Step 703: When the cooling fan is running at each preset speed and the cooling fan and at least one recording element are synchronously rotated to each rotation angle, at least one recording element collects the sound source signal of the cooling fan once.

Take a plurality of different preset speeds including a first preset speed and a second preset speed as an example. When the fan control module 114 controls the cooling fan 200 to operate at the first preset speed, the driving mechanism 111 drives the cooling fan 200 and at least one recording element 113 on the test base plate 112 to rotate synchronously to a plurality of different rotation angles. When the cooling fan 200 operates at the first preset speed, and the cooling fan 200 and at least one recording element 113 rotate synchronously to each of the plurality of different rotation angles, at least one recording element 113 collects the sound source signal of the cooling fan 200 at each rotation angle.

Next, when the fan control module 114 controls the cooling fan 200 to operate at a second preset speed, the driving mechanism 111 drives the cooling fan 200 and at least one recording element 113 on the test base plate 112 to rotate synchronously to a plurality of different rotation angles. When the cooling fan 200 operates at the second preset speed and the cooling fan 200 and at least one recording element 113 rotate synchronously to each of a plurality of different rotation angles, at least one recording element 113 collects the sound source signal of the cooling fan 200 at each rotation angle.

In some embodiments, the at least one recording element 113 includes a first recording element 1131 and a second recording element 1132, and the first recording element 1131 and the second recording element 1132 are respectively located on opposite sides of the test base plate 112. The plurality of different rotation angles include a first rotation angle, a second rotation angle, and a third rotation angle, wherein the first rotation angle is 0°, the second rotation angle is 90°, and the third rotation angle is 180°.

Step 704: at least one recording element sends each sound source signal collected to an abnormal sound detection module.

Step 705: The abnormal sound detection module detects whether there is an abnormal sound from the cooling fan according to each sound source signal.

The following takes at least one recording element 113 including a first recording element 1131 and a second recording element 1132, a plurality of different preset rotation speeds including a first preset rotation speed and a second preset rotation speed, a plurality of different rotation angles including a first rotation angle, a second rotation angle and a third rotation angle, and the first rotation angle is 0°, the second rotation angle is 90°, and the third rotation angle is 180° as an example to illustrate the specific process of collecting sound source signals for the cooling fan 200 in an embodiment of the present application.

For example, FIG8 is a flow chart of using a recording element to collect a sound source signal of a cooling fan in an embodiment of the present application. Referring to FIG8 , the process may specifically include the following steps:

Step 801, placing the cooling fan in the limiting groove of the test base plate.

Step 802: fix the cooling fan on the test base plate using a fixing bracket.

In the embodiment of the present application, the cooling fan 200 can be manually placed in the limiting groove of the test base plate 112, and then the motor drives the fixing bracket 115 to fix the cooling fan 200 on the test base plate 112. Then, the following test process is executed.

Step 803: the fan control module controls the cooling fan to operate at a first preset speed.

Step 804, when the cooling fan is running at a first preset speed, the driving mechanism drives the cooling fan, the first recording element and the second recording element on the test base plate to rotate synchronously to 0°, 90° and 180°, and uses the first recording element and the second recording element to respectively collect the sound source signal at each rotation angle.

When the fan control module 114 controls the cooling fan 200 to operate at the first preset speed, the driving mechanism 111 first drives the cooling fan 200, the first recording element 1131 and the second recording element 1132 on the test base plate 112 to rotate synchronously to 0°, at which time the first recording element 1131 and the second recording element 1132 respectively collect the sound source signal of the cooling fan 200 once; the driving mechanism 111 then drives the cooling fan 200, the first recording element 1131 and the second recording element 1132 on the test base plate 112 to rotate synchronously to 90°, at which time the first recording element 1131 and the second recording element 1132 respectively collect the sound source signal of the cooling fan 200 once; the driving mechanism 111 continues to drive the cooling fan 200, the first recording element 1131 and the second recording element 1132 on the test base plate 112 to rotate synchronously to 180°, at which time the first recording element 1131 and the second recording element 1132 respectively collect the sound source signal of the cooling fan 200 once.

Step 805: the fan control module controls the cooling fan to operate at a second preset speed.

Step 806, when the cooling fan is running at a second preset speed, the driving mechanism drives the cooling fan, the first recording element and the second recording element on the test base plate to rotate synchronously to 0°, 90° and 180°, and uses the first recording element and the second recording element to respectively collect the sound source signal at each rotation angle.

After the first recording element 1131 and the second recording element 1132 respectively collect the sound source signals at the first preset speed and the rotation angles of 0°, 90° and 180°, the fan control module 114 adjusts the fan speed of the cooling fan 200 to the second preset speed.

When the fan control module 114 controls the cooling fan 200 to operate at the second preset speed, the above process is repeated, that is, the driving mechanism 111 first drives the cooling fan 200, the first recording element 1131 and the second recording element 1132 on the test base plate 112 to rotate synchronously to 0°, at which time the first recording element 1131 and the second recording element 1132 respectively collect the sound source signal of the cooling fan 200 once; the driving mechanism 111 then drives the cooling fan 200, the first recording element 1131 and the second recording element 1132 on the test base plate 112 to rotate synchronously to 90°, at which time the first recording element 1131 and the second recording element 1132 respectively collect the sound source signal of the cooling fan 200 once; the driving mechanism 111 continues to drive the cooling fan 200, the first recording element 1131 and the second recording element 1132 on the test base plate 112 to rotate synchronously to 180°, at which time the first recording element 1131 and the second recording element 1132 respectively collect the sound source signal of the cooling fan 200 once.

Step 807: The first recording element and the second recording element send the collected sound source signal to the abnormal sound detection module to detect whether the cooling fan has abnormal sound.

Step 808, the fixing bracket releases the cooling fan, and removes the cooling fan on the test base plate.

After the first recording element 1131 and the second recording element 1132 send the collected multiple sound source signals to the abnormal sound detection module 120, the abnormal sound detection module 120 detects whether the cooling fan 200 has abnormal sound according to the multiple sound source signals, thereby completing the abnormal sound detection process of the cooling fan 200. Then, the fixing bracket is driven by the motor to release the cooling fan 200, and the cooling fan 200 on the test base plate 112 is manually removed.

For example, FIG9 is a flow chart of the abnormal sound detection module of the embodiment of the present application detecting whether there is abnormal sound from the cooling fan according to the sound source signal. Referring to FIG9 , it may specifically include the following steps:

Step 901: The abnormal sound detection module obtains each sound source signal collected by the recording element.

In the embodiment of the present application, taking the example of at least one recording element 113 including a first recording element 1131 and a second recording element 1132, the first recording element 1131 sends the sound source signal of the cooling fan 200 it collects to the abnormal sound detection module 120, and the second recording element 1132 also sends the sound source signal of the cooling fan 200 it collects to the abnormal sound detection module 120.

Step 902: The abnormal sound detection module performs bandpass filtering on each sound source signal.

Step 903: The abnormal sound detection module performs Fourier transform on each sound source signal after the bandpass filtering process to obtain a frequency spectrum corresponding to each sound source signal.

Step 904: The abnormal sound detection module extracts the frequency band to be analyzed in the frequency spectrum corresponding to each sound source signal.

Step 905 : The abnormal sound detection module calculates the average spectrum kurtosis and the average spectrum peak value of each sound source signal according to the to-be-analyzed frequency band corresponding to each sound source signal.

In some embodiments, the frequency band to be analyzed includes multiple octave frequency bands corresponding to the rotation frequency of the cooling fan 200. Specifically, the abnormal sound detection module 120 calculates the average spectrum kurtosis and average spectrum peak value of each sound source signal in the following manner: the abnormal sound detection module 120 calculates the spectrum kurtosis and spectrum peak value corresponding to each octave frequency band included in the frequency band to be analyzed corresponding to each sound source signal; the abnormal sound detection module 120 calculates the average value of the spectrum kurtosis corresponding to multiple octave frequency bands included in the frequency band to be analyzed corresponding to each sound source signal, and obtains the average spectrum kurtosis of each sound source signal; the abnormal sound detection module 120 calculates the average value of the spectrum peak value corresponding to multiple octave frequency bands included in the frequency band to be analyzed corresponding to each sound source signal, and obtains the average spectrum peak value of each sound source signal.

Therefore, according to the implementation of the above steps 902 to 905, the foreign sound detection module 120 can calculate the average spectrum kurtosis and the average spectrum peak value of each sound source signal.

Step 906: The abnormal sound detection module performs high-pass filtering on each sound source signal.

Step 907: The abnormal sound detection module uses a human ear hearing model to filter each sound source signal after high-pass filtering.

Step 908: The abnormal sound detection module calculates the sound pressure level of each sound source signal after filtering using the human ear hearing model.

In some embodiments, the abnormal sound detection module 120 specifically adopts the following method to calculate the sound pressure level of each sound source signal after filtering using the human ear auditory model: the abnormal sound detection module 120 calculates the sampling value corresponding to each sound source signal after filtering using the human ear auditory model, and multiplies it by the reference voltage of the analog-to-digital conversion to obtain the voltage value corresponding to each sound source signal; the abnormal sound detection module 120 calculates the voltage value corresponding to each sound source signal, and the ratio of the sensitivity of the recording element 113 to obtain the sound pressure of each sound source signal; the abnormal sound detection module 120 calculates the sound pressure level of each sound source signal by the following formula: SPL=20×lg(P _e /P _ref ); wherein SPL represents the sound pressure level of each sound source signal, P _e represents the sound pressure of each sound source signal, and _Pref represents the reference sound pressure.

Therefore, according to the above steps 906 and 908, the abnormal sound detection module 120 can calculate the sound pressure level of each sound source signal.

Step 909: The abnormal sound detection module determines whether there is an abnormal sound from the cooling fan according to the average spectrum kurtosis, average spectrum peak and sound pressure level of each sound source signal.

In some embodiments, the abnormal sound detection module 120 may use the following method to determine whether the cooling fan 200 has abnormal sound: when the average spectral kurtosis of each sound source signal is less than the spectral kurtosis threshold, the average spectral peak of each sound source signal is less than the spectral peak threshold, and the sound pressure level of each sound source signal is less than the sound pressure level threshold, the abnormal sound detection module 120 determines that the cooling fan 200 does not have abnormal sound; when the average spectral kurtosis of at least one sound source signal is greater than or equal to the spectral kurtosis threshold, and/or the average spectral peak of at least one sound source signal is greater than or equal to the spectral peak threshold, and/or the sound pressure level of at least one sound source signal is greater than or equal to the sound pressure level threshold, the abnormal sound detection module 120 determines that the cooling fan 200 has abnormal sound.

In summary, the embodiment of the present application uses the recording element 113 to collect the sound source signal of the cooling fan 200 when the cooling fan 200 is at multiple different preset speeds and multiple different rotation angles. The cooling fan 200 runs at multiple different preset speeds, which can increase the possibility that the cooling fan 200 with abnormal sound is stimulated to produce abnormal sound during the detection process, thereby improving the accuracy of the abnormal sound detection result of the cooling fan 200. In addition, when the cooling fan 200 rotates to multiple different rotation angles, the recording element 113 and the cooling fan 200 rotate synchronously, so that when the cooling fan 200 rotates to different rotation angles, the angle and relative position between the cooling fan 200 and the recording element 113 will not change, which can improve the consistency of the sound source signal collected by the recording element 113 at different rotation angles of the cooling fan 200, thereby improving the accuracy of the abnormal sound detection result of the cooling fan 200.

The present application embodiment is described with reference to the flowchart and/or block diagram of the method and device (system) according to the embodiment of the present application. It should be understood that each process and/or box in the flowchart and/or block diagram, and the combination of the process and/or box in the flowchart and/or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processing unit of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processing unit of the computer or other programmable data processing device produce a device for implementing the function specified in one process or multiple processes in the flowchart and/or one box or multiple boxes in the block diagram.

The above specific implementation methods further illustrate the purpose, technical solutions and beneficial effects of the present application in detail. It should be understood that the above are only specific implementation methods of the present application and are not used to limit the scope of protection of the present application. Any modifications, equivalent substitutions, improvements, etc. made on the basis of the technical solutions of the present application should be included in the scope of protection of the present application.

Claims (16)

1. The abnormal sound detection method of the fan is characterized by being applied to an abnormal sound detection system of the fan, wherein the abnormal sound detection system of the fan comprises a sound source acquisition device and an abnormal sound detection module, the sound source acquisition device comprises a driving mechanism, a test base plate, at least one recording element and a fan control module, the driving mechanism is respectively connected with the test base plate and the at least one recording element, a cooling fan is fixed on the test base plate, the fan control module is electrically connected with the cooling fan, and the at least one recording element is electrically connected with the abnormal sound detection module; the method comprises the following steps:

the fan control module controls the cooling fan to sequentially run at a plurality of different preset rotating speeds;

Under the condition that the cooling fan runs at each preset rotating speed, the driving mechanism drives the cooling fan and the at least one recording element on the test bottom plate to synchronously rotate to a plurality of different rotating angles;

Under the condition that the cooling fan runs at each preset rotating speed and the cooling fan and the at least one recording element synchronously rotate to each rotating angle, the at least one recording element collects sound source signals of the cooling fan once;

The at least one recording element sends each acquired sound source signal to the abnormal sound detection module;

the abnormal sound detection module detects whether abnormal sound exists in the cooling fan according to each sound source signal;

the abnormal sound detection module detects whether abnormal sound exists in the cooling fan according to each sound source signal, and the abnormal sound detection module comprises:

The abnormal sound detection module calculates average spectrum kurtosis and average spectrum peak value of each sound source signal;

the abnormal sound detection module calculates the sound pressure level of each sound source signal;

The abnormal sound detection module determines whether abnormal sound exists in the cooling fan according to the average spectral kurtosis, the average spectral peak value and the sound pressure level of each sound source signal;

The fan control module comprises an upper controller, a voltage output module and a counter module, wherein the upper controller is respectively and electrically connected with the voltage output module and the counter module, and the voltage output module and the counter module are also electrically connected with the cooling fan.

2. The method of claim 1, wherein the alien detection module calculates an average spectral kurtosis and an average spectral peak for each of the sound source signals, comprising:

the abnormal sound detection module carries out band-pass filtering processing on each sound source signal;

the abnormal sound detection module performs Fourier transform on each sound source signal subjected to band-pass filtering processing to obtain a frequency spectrum corresponding to each sound source signal;

The abnormal sound detection module extracts a frequency band to be analyzed in a frequency spectrum corresponding to each sound source signal;

and the abnormal sound detection module calculates and obtains the average spectral kurtosis and the average spectral peak value of each sound source signal according to the frequency band to be analyzed corresponding to each sound source signal.

3. The method of claim 2, wherein the frequency band to be analyzed includes a plurality of frequency multiplication frequency bands corresponding to a frequency conversion of the cooling fan; the abnormal sound detection module calculates an average spectral kurtosis and an average spectral peak value of each sound source signal according to the frequency band to be analyzed corresponding to each sound source signal, and the abnormal sound detection module comprises the following steps:

The abnormal sound detection module calculates the spectral kurtosis and the spectral peak value corresponding to each frequency multiplication frequency band in the frequency band to be analyzed corresponding to each sound source signal;

The abnormal sound detection module calculates an average value of the spectral kurtosis corresponding to the multiple frequency multiplication frequency bands in the frequency bands to be analyzed corresponding to each sound source signal, and obtains the average spectral kurtosis of each sound source signal;

And the abnormal sound detection module calculates the average value of the frequency spectrum peak values corresponding to the multiple frequency multiplication frequency bands in the frequency bands to be analyzed corresponding to each sound source signal, and obtains the average frequency spectrum peak value of each sound source signal.

4. The method of claim 1, wherein the abnormal sound detection module calculates a sound pressure level of each of the sound source signals, comprising:

the abnormal sound detection module carries out high-pass filtering processing on each sound source signal;

the abnormal sound detection module adopts a human ear auditory model to carry out filtering treatment on each sound source signal after the high-pass filtering treatment;

and the abnormal sound detection module calculates the sound pressure level of each sound source signal after the filtering processing of the human ear auditory model.

5. The method of claim 4, wherein the abnormal sound detection module calculates a sound pressure level of each of the sound source signals filtered using the human ear auditory model, comprising:

the abnormal sound detection module calculates a sampling value corresponding to each sound source signal after filtering processing by the human ear auditory model, and products of the sampling values and reference voltages of analog-to-digital conversion to obtain a voltage value corresponding to each sound source signal;

The abnormal sound detection module calculates a voltage value corresponding to each sound source signal and a ratio of the voltage value to the sensitivity of the recording element to obtain the sound pressure of each sound source signal;

the abnormal sound detection module calculates the sound pressure level of each sound source signal according to the following formula: wherein SPL represents the sound pressure level of each of the sound source signals, Represents the sound pressure of each of the sound source signals,Representing a reference sound pressure.

6. The method of claim 1, wherein the abnormal sound detection module determining whether the heat dissipation fan has abnormal sound based on the average spectral kurtosis, the average spectral peak, and the sound pressure level of each of the sound source signals comprises:

when the average spectral kurtosis of each sound source signal is smaller than a spectral kurtosis threshold, the average spectral peak of each sound source signal is smaller than a spectral peak threshold, and the sound pressure level of each sound source signal is smaller than a sound pressure level threshold, the abnormal sound detection module determines that the cooling fan has no abnormal sound;

The abnormal sound detection module determines that the cooling fan has abnormal sound when the average spectral kurtosis of at least one of the sound source signals is greater than or equal to the spectral kurtosis threshold, and/or the average spectral peak of at least one of the sound source signals is greater than or equal to the spectral peak threshold, and/or the sound pressure level of at least one of the sound source signals is greater than or equal to the sound pressure level threshold.

7. The method of claim 1, wherein the fan control module controls the cooling fan to operate sequentially at a plurality of different preset rotational speeds, comprising:

the upper controller sends a control signal to the voltage output module;

the voltage output module provides a voltage signal for the cooling fan according to the control signal; the voltage signal is used for driving the cooling fan to operate;

the counter module detects the fan rotating speed in the running process of the cooling fan and sends the fan rotating speed to the upper controller;

the upper controller calculates the rotation speed deviation between the rotation speed of the fan and the preset rotation speed;

the upper controller determines a voltage compensation value according to the rotating speed deviation;

The upper controller adjusts the control signal sent to the voltage output module according to the voltage compensation value, and then adjusts the voltage signal provided to the cooling fan by the voltage output module; the adjusted voltage signal is used for adjusting the fan rotating speed in the running process of the cooling fan to the preset rotating speed.

8. The method of any of claims 1 to 7, wherein the at least one sound recording element comprises a first sound recording element and a second sound recording element, the first sound recording element and the second sound recording element being located on opposite sides of the test chassis, respectively;

The plurality of different preset rotational speeds comprise a first preset rotational speed and a second preset rotational speed, wherein the first preset rotational speed is 4000+/-50 rpm, and the second preset rotational speed is 2500+/-50 rpm;

The plurality of different rotation angles includes a first rotation angle of 0 °, a second rotation angle of 90 °, and a third rotation angle of 180 °.

9. The abnormal sound detection system of the fan is characterized by comprising a sound source acquisition device and an abnormal sound detection module, wherein the sound source acquisition device comprises a driving mechanism, a test bottom plate, at least one recording element and a fan control module, the driving mechanism is respectively connected with the test bottom plate and the at least one recording element, a cooling fan is fixed on the test bottom plate, the fan control module is electrically connected with the cooling fan, and the at least one recording element is electrically connected with the abnormal sound detection module;

the fan control module is used for controlling the cooling fan to sequentially run at a plurality of different preset rotating speeds;

The driving mechanism is used for driving the cooling fan and the at least one recording element on the test bottom plate to synchronously rotate to a plurality of different rotation angles under the condition that the cooling fan runs at each preset rotation speed;

The at least one recording element is used for collecting sound source signals of the cooling fan once under the condition that the cooling fan runs at each preset rotating speed and the cooling fan and the at least one recording element synchronously rotate to each rotating angle;

the at least one recording element is further configured to send each collected sound source signal to the abnormal sound detection module;

the abnormal sound detection module is used for detecting whether abnormal sound exists in the cooling fan according to each sound source signal;

The abnormal sound detection module is specifically configured to:

calculating the average spectral kurtosis and the average spectral peak value of each sound source signal;

calculating the sound pressure level of each sound source signal;

determining whether or not the heat radiation fan has abnormal sound according to the average spectral kurtosis, the average spectral peak value and the sound pressure level of each sound source signal;

The fan control module comprises an upper controller, a voltage output module and a counter module, wherein the upper controller is respectively and electrically connected with the voltage output module and the counter module, and the voltage output module and the counter module are also electrically connected with the cooling fan.

10. The system according to claim 9, wherein the abnormal sound detection module is specifically configured to:

carrying out band-pass filtering processing on each sound source signal;

Performing Fourier transform on each sound source signal subjected to band-pass filtering processing to obtain a frequency spectrum corresponding to each sound source signal;

Extracting a frequency band to be analyzed in a frequency spectrum corresponding to each sound source signal;

and calculating to obtain the average spectral kurtosis and the average spectral peak value of each sound source signal according to the frequency band to be analyzed corresponding to each sound source signal.

11. The system of claim 10, wherein the frequency band to be analyzed comprises a plurality of frequency multiplication frequency bands corresponding to a frequency conversion of the cooling fan; the abnormal sound detection module is specifically configured to:

calculating the spectral kurtosis and the spectral peak value corresponding to each frequency multiplication frequency band in the frequency band to be analyzed corresponding to each sound source signal;

Calculating the average value of the spectral kurtosis corresponding to the multiple frequency multiplication frequency bands in the frequency bands to be analyzed corresponding to each sound source signal to obtain the average spectral kurtosis of each sound source signal;

and calculating the average value of the frequency spectrum peak values corresponding to the multiple frequency multiplication frequency bands in the frequency bands to be analyzed corresponding to each sound source signal, and obtaining the average frequency spectrum peak value of each sound source signal.

12. The system according to claim 9, wherein the abnormal sound detection module is specifically configured to:

carrying out high-pass filtering processing on each sound source signal;

Filtering each sound source signal subjected to high-pass filtering by adopting a human ear auditory model;

and calculating the sound pressure level of each sound source signal after the filtering processing of the human ear auditory model.

13. The system according to claim 12, wherein the abnormal sound detection module is specifically configured to:

Calculating a sampling value corresponding to each sound source signal after filtering processing by adopting the human ear auditory model, and multiplying the sampling value by the reference voltage of analog-to-digital conversion to obtain a voltage value corresponding to each sound source signal;

Calculating the voltage value corresponding to each sound source signal and the ratio of the voltage value to the sensitivity of the recording element to obtain the sound pressure of each sound source signal;

the sound pressure level of each sound source signal is calculated by the following formula: wherein SPL represents the sound pressure level of each of the sound source signals, Represents the sound pressure of each of the sound source signals,Representing a reference sound pressure.

14. The system according to claim 9, wherein the abnormal sound detection module is specifically configured to:

when the average spectral kurtosis of each sound source signal is smaller than a spectral kurtosis threshold, the average spectral peak of each sound source signal is smaller than a spectral peak threshold, and the sound pressure level of each sound source signal is smaller than a sound pressure level threshold, determining that abnormal sound does not exist in the cooling fan;

Determining that the cooling fan has abnormal sound when the average spectral kurtosis of at least one of the sound source signals is greater than or equal to the spectral kurtosis threshold, and/or the average spectral peak of at least one of the sound source signals is greater than or equal to the spectral peak threshold, and/or the sound pressure level of at least one of the sound source signals is greater than or equal to the sound pressure level threshold.

15. The system of claim 9, wherein the system further comprises a controller configured to control the controller,

The upper controller is used for sending a control signal to the voltage output module;

The voltage output module is used for providing a voltage signal for the cooling fan according to the control signal; the voltage signal is used for driving the cooling fan to operate;

The counter module is used for detecting the fan rotating speed in the running process of the cooling fan and sending the fan rotating speed to the upper controller;

the upper controller is also used for calculating the rotation speed deviation between the rotation speed of the fan and the preset rotation speed;

the upper controller is also used for determining a voltage compensation value according to the rotating speed deviation;

The upper controller is further configured to adjust the control signal sent to the voltage output module according to the voltage compensation value, so as to adjust the voltage signal provided to the cooling fan by the voltage output module; the adjusted voltage signal is used for adjusting the fan rotating speed in the running process of the cooling fan to the preset rotating speed.

16. The system of any of claims 9 to 15, wherein the at least one sound recording element comprises a first sound recording element and a second sound recording element, the first sound recording element and the second sound recording element being located on opposite sides of the test floor, respectively;

The plurality of different preset rotational speeds comprise a first preset rotational speed and a second preset rotational speed, wherein the first preset rotational speed is 4000+/-50 rpm, and the second preset rotational speed is 2500+/-50 rpm;

The plurality of different rotation angles includes a first rotation angle of 0 °, a second rotation angle of 90 °, and a third rotation angle of 180 °.