Method and device for detecting a gearbox fault

Abstract

The present invention provides a method for detecting a failure of a transmission, comprising: obtaining detection data of the transmission; dividing the detection data into a plurality of sub-band data groups; obtaining a characteristic value of each sub-band data group of the plurality of sub-band data groups; and determining, based on all the obtained characteristic values, whether a failure occurs in the transmission. According to the method and apparatus for detecting a failure of a transmission of the present disclosure, a failure state of the transmission can be determined by dividing the detection data into a plurality of sub-band data groups and by each sub-band data group, thereby improving the accuracy of the failure detection of the transmission and reducing the influence of noise on the failure detection of the transmission.

Description

[0001] The present application relates to the field of data processing, in particular to a method and a device for detecting a fault in a transmission.

[0002] As a vehicle's powertrain, the transmission plays a crucial role in the vehicle's safe operation. Therefore, it is necessary to detect the transmission's fault condition.

[0003] Generally, when detecting the fault condition of a transmission, a spectral analysis method such as cepstrum analysis is used to analyze gear vibration signals. For example, the meshing frequency of the transmission gears and the change in sideband energy are detected using the spectral analysis method to determine whether a fault occurs in the transmission. However, this detection method is easily affected by road noise and vehicle body vibration, causing the meshing frequency and sideband energy to be lost in the noise and cannot be accurately detected. This in turn leads to the inability to accurately detect a transmission fault, and, for example, to the inability to detect a transmission fault in a timely and accurate manner during vehicle operation.

[0004] Therefore, an effective method for detecting a transmission failure is extremely important. There is a need for a method for accurately detecting a transmission failure.

[0005] According to one aspect of the present disclosure, a method for detecting a failure of a transmission is provided, the method comprising: obtaining detection data of the transmission; dividing the detection data into a plurality of groups of sub-band data; obtaining a characteristic value of each group of sub-band data of the plurality of groups of sub-band data; and determining, based on all of the obtained characteristic values, whether a failure occurs in the transmission.

[0006] According to another aspect of the present disclosure, there is provided an apparatus for detecting a failure of a transmission, the apparatus comprising: a data obtaining unit configured to obtain detection data of the transmission; a data dividing unit configured to divide the detection data into a plurality of groups of sub-band data; a characteristic value obtaining unit configured to obtain a characteristic value of each group of sub-band data of the plurality of groups of sub-band data; and a failure determining unit configured to determine, based on all the obtained characteristic values, whether a failure occurs in the transmission.

[0007] According to another aspect of the present disclosure, a computer-readable medium is provided having stored thereon instructions that, when executed by the processor, cause a processor to perform the above method for detecting a fault of a transmission according to an embodiment of the present disclosure.

[0008] According to the method and apparatus for detecting a failure of a transmission of the present disclosure, a failure state of the transmission can be determined by dividing the detection data into a plurality of groups of sub-band data and by the individual groups of sub-band data, whereby the accuracy of the failure detection of the transmission can be improved and the influence of noise on the failure detection of the transmission can be reduced.

[0009] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly presents the drawings to be used in the embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative effort. Fig. 1 shows a flowchart of a method for detecting a fault of a transmission according to an exemplary embodiment of the present disclosure. Fig. 2 shows a flowchart of a method for detecting a fault of a transmission according to another exemplary embodiment of the present disclosure. Fig. 3 shows a flowchart of a method for detecting a fault of a transmission according to another exemplary embodiment of the present disclosure. Fig. 4 shows a flowchart of a method for detecting a fault of a transmission according to another exemplary embodiment of the present disclosure. Fig. 5 shows a flowchart of a method for detecting a fault of a transmission according to another exemplary embodiment of the present disclosure. Fig. 6 shows a block diagram of a device for detecting a fault of a transmission according to an exemplary embodiment of the present disclosure.

[0010] The features and exemplary embodiments of the present invention according to various aspects are described in detail below. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that the present invention may be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the present invention by illustrating examples of the present invention. The present invention is by no means limited to a particular configuration and algorithm shown below, but covers any modification, substitution, and improvement of elements, components, and algorithms without departing from the spirit of the present invention.In the drawings and the following description, well-known structures and techniques are not shown in order not to unnecessarily obscure the present invention.

[0011] Fig. 1 shows a flowchart of a method for detecting a fault of a transmission according to an exemplary embodiment of the present disclosure.

[0012] The transmission can be a transmission of any device with a drive train. For example, the transmission can be a transmission of a vehicle traveling on a road.

[0013] With reference to Fig. 1, the detection data of the transmission is obtained in step S110.

[0014] In one embodiment, the detection data can be vibration data or sound data. The detection data can be, for example, vibration data detected by an acceleration sensor for the transmission or sound data detected by a microphone for the transmission. The detection data can be, for example, data measured from the transmission while the vehicle is moving, i.e., measurement data in the time domain.

[0015] In step S120, the detection data is divided into a plurality of groups of sub-band data, each group of sub-band data corresponding to a frequency band.

[0016] In one embodiment, in step S120, the detection data may be divided into a plurality of groups of subband data of a plurality of frequency bands according to a predetermined octave within a predetermined frequency range.

[0017] For example, in order to effectively divide the acquisition data, whether vibration data or sound data, the above-mentioned predetermined frequency range can be set to a frequency range of 20 Hz to 20 kHz, and the above-mentioned predetermined octave can be set to 1 / 3 octave. In this case, the acquisition data can be divided into 31 groups of sub-band data corresponding to 31 frequency bands, with the lower limit frequency f n and the upper limit frequency f n+1 each frequency band must satisfy the following equation: fn+1=21 / 3fn.

[0018] For example, the acquisition data can be filtered using filters corresponding to the respective frequency bands to obtain individual groups of subband data for the respective frequency bands. It should be understood that the above frequency ranges and octaves for dividing the acquisition data are only examples, and any other frequency ranges and octaves can be set according to actual needs.

[0019] In this way, the influence of noise (e.g. noise generated by the roads and vibrations of the vehicle body while the vehicle is moving) on the transmission's fault detection can be reduced.

[0020] In step S130, a characteristic value of each group of subband data of the plurality of groups of subband data is obtained.

[0021] The characteristic value can be any characteristic value that can indicate the health status (fault status) of the transmission.

[0022] In step S140, it is determined whether a fault occurs in the transmission based on all the characteristic values obtained.

[0023] Since the characteristic value obtained in step S130 can indicate the health status of the transmission, the individual characteristic values can be used in step S140 to determine whether a fault occurs in the transmission.

[0024] According to the method for detecting a failure of a transmission in the present invention, the failure state of the transmission can be determined by dividing the detection data into a plurality of groups of sub-band data and by the individual groups of sub-band data, whereby the accuracy of the failure detection of the transmission can be improved and the influence of noise on the failure detection of the transmission can be reduced.

[0025] Fig. 2 shows a flowchart of a method for detecting a fault of a transmission according to another exemplary embodiment of the present disclosure.

[0026] With reference to Fig. 1 and Fig. 2, steps S110, S120 and S140 are in Fig. 2 each with steps S110, S120 and S140 in Fig. 1 is identical, and the difference is that in Fig. 2 with steps S131, S132 and S133 an example of step S130 in Fig. 1 is shown in detail.

[0027] In step S131, the envelope of each group of subband data may be detected in the time domain to obtain envelope data of each group of subband data.

[0028] In one embodiment, a Hilbert transform may be performed on each group of subband data to detect the envelope of that group of subband data and thereby obtain its envelope data.

[0029] In step S132, a fast Fourier transform may be performed on the envelope data of each group of subband data to obtain frequency domain subband data of each group of subband data.

[0030] Here, since fast Fourier transform is performed on the envelope data of each subband data group, the obtained frequency-domain subband data of each subband data group can be distributed in a frequency band with a low frequency to facilitate subsequent processing. For example, in the above division of the detection data into 31 subband data groups of the 31 frequency bands according to 1 / 3 octave in the frequency range from 20 Hz to 20 kHz, the frequency-domain subband data of each subband data group obtained in step S132 can be distributed in a frequency range from a few hertz to several hundred hertz.

[0031] In step S133, a modulation frequency corresponding to the frequency-domain subband data of each group of subband data can be obtained. Here, the modulation frequency is a frequency with the maximum amplitude on an amplitude-frequency curve corresponding to the frequency-domain subband data.

[0032] For example, after obtaining the frequency-domain subband data of each group of subband data, an amplitude-frequency curve corresponding to the frequency-domain subband data can be obtained, with a horizontal axis representing frequency and a vertical axis representing amplitude. Then, the frequency with the largest amplitude on the amplitude-frequency curve can be determined as the modulation frequency.

[0033] The modulation frequency obtained as above may be a characteristic value of the corresponding group of subband data. Subsequently, in step S140, it may be determined whether a fault is occurring in the transmission based on the individual modulation frequencies of each group of subband data. Referring to Fig. 3, an example is described below in which the individual modulation frequencies are used to determine whether a fault occurs in the gearbox.

[0034] Fig. 3 shows a flowchart of a method for detecting a fault of a transmission according to another exemplary embodiment of the present disclosure.

[0035] With reference to Fig. 2 and Fig. 3, steps S110, S120 and S130 are in Fig. 3 each with steps S110, S120 and S130 in Fig. 2 are identical, and the difference is that in Fig. 3 with steps S141, S142 and S143 an example of step S140 in Fig. 2 is shown in detail.

[0036] With reference to Fig. 3, in step S141, it can be determined whether an error modulation frequency is present in all obtained modulation frequencies. Here, the error modulation frequency can be a modulation frequency that is identical to an error frequency in a predetermined error frequency set.

[0037] In one embodiment, step S141 may include: determining a speed of the transmission; obtaining an error frequency set corresponding to the speed; and determining whether, in all obtained modulation frequencies, there is an error modulation frequency that is identical to an error frequency in this error frequency set.

[0038] For example, different error frequency sets corresponding to different speeds of the transmission can be prestored. After determining the speed of the transmission at the time the acquisition data is obtained, an error frequency set corresponding to that speed can be retrieved. Thus, based on the retrieved error frequency set, it is determined whether an error modulation frequency exists in the modulation frequencies corresponding to each group of subband data.

[0039] In the event that it is determined in step S141 that an error modulation frequency is present (“yes” in Fig. 3), step S142 may be performed to determine that a fault is occurring in the transmission.

[0040] In the event that it is determined in step S141 that there is no error modulation frequency (“no” in Fig. 3), step S143 may be performed to determine that no fault occurs in the transmission.

[0041] Here, when it is determined that a failure occurs in the transmission, the method for detecting a failure of a transmission according to the present disclosure may further comprise, in one embodiment, to further detect the failure: determining a frequency band corresponding to the error modulation frequency, which is one of a plurality of frequency bands into which the plurality of groups of sub-band data are divided; and determining the position at which the failure of the transmission occurs from the frequency band.

[0042] For example, vibration or sound signals in different frequency bands may be generated when a gear of the transmission and various components of a bearing of the transmission (e.g., an outer race, an inner race, a roller, etc.) are faulty. Thus, the fault location in the transmission can be determined by determining the frequency band of the subband data that corresponds to the fault modulation frequency determined in step S141.

[0043] In order to more accurately detect the condition of the transmission (regardless of whether a fault has been detected in the transmission), the method for detecting a fault of a transmission according to the present disclosure may further determine a “roughness” of the detection data, which is used to indicate a degree of fault of the transmission, as described below in Fig. 4 shown.

[0044] Fig. 4 shows a flowchart of a method for detecting a fault of a transmission according to another exemplary embodiment of the present disclosure.

[0045] With reference to Fig. 3 and Fig. 4, steps S110, S120 and S140 are in Fig. 4 each with steps S110, S120 and S140 in Fig. 3 is identical, and the difference is that step S130 in Fig. 4 further comprises a step S134, and Fig. 4 further comprises a step S150.

[0046] In step S134, a modulation depth corresponding to the frequency-domain subband data of each subband data group may be obtained. Here, the modulation depth may be a sum of the amplitude of the modulation frequency on the above amplitude-frequency curve and the amplitude of a multiple frequency of the modulation frequency.

[0047] For example, after obtaining the amplitude-frequency curve corresponding to the frequency-domain subband data of each group of subband data and obtaining the frequency with the maximum amplitude on the amplitude-frequency curve (i.e., the modulation frequency), 2 times the frequency, 3 times the frequency, ..., m times the frequency of this frequency, and a sum of the amplitudes of these frequencies can be obtained as the modulation depth. For example, m can be any value set according to actual needs, such as m = 5. It should be understood that the above values are only examples and can be set to any value according to actual needs.

[0048] In step S150, the roughness of the acquisition data can be determined based on all obtained modulation frequencies and all obtained modulation depths, where the roughness indicates the degree of error of the transmission.

[0049] In one embodiment, the roughness can be expressed by the following equation: RVA=k×∑1Nfi×ΔLi

[0050] R VA is the roughness, k is a constant coefficient determined based on an operating condition of the transmission (for example, k can be set to 0.25 for the transmission of a vehicle in the normal driving condition of the vehicle), f i is a modulation frequency corresponding to the i-th group of subband data, ΔL i is a modulation depth corresponding to the i-th group of subband data, and N is a total number of groups of the plural groups of subband data, where i and N are each an integer and 1 ≤ i ≤ N.

[0051] The degree of gear failure can be determined by the roughness determined above. For example, in the case of a gear failure, the greater the roughness R, the more serious the gear failure.VA Furthermore, the degree of failure in a fault-free gearbox can indicate a possible failure tendency of the gearbox. For example, the greater the roughness R VA is, the greater the potential error tendency of the gear. That is, the roughness R VA may indicate the effect of the vibration signal or the sound signal of the transmission.

[0052] This allows the condition of the transmission to be determined even more precisely.

[0053] Furthermore, as an alternative embodiment, the “roughness” of the acquisition data can be used to determine whether a fault is occurring in the transmission, as described below in Fig. 5 shown.

[0054] Fig. 5 shows a flowchart of a method for detecting a fault of a transmission according to another exemplary embodiment of the present disclosure.

[0055] With reference to Fig. 4 and Fig. 5, steps S110, S120 and S130 are in Fig. 5 each with steps S110, S120 and S130 in Fig. 4 are identical, and the difference is that in Fig. 5 step S150 is carried out to determine the roughness after step S130 and then in step S140 it is determined based on the determined roughness whether a fault occurs in the transmission.

[0056] Here, the process performed in step S150 can be combined with the process performed in step S150, which is Fig. 4 and is not described in detail here.

[0057] After the roughness has been determined, for example, in step S140, the determined roughness can be compared with a predetermined fault threshold. It can be determined that no fault is occurring in the transmission if the roughness is less than the fault threshold, and it can be determined that a fault is occurring in the transmission if the roughness is equal to or greater than the fault threshold. The fault threshold can be set to different values depending on the device in which the transmission is installed and / or the operating state of the transmission.

[0058] After determining whether a fault occurs in the gearbox as described above, the fault degree can also be further determined based on the roughness value as described above.

[0059] Furthermore, it is understood that in this embodiment it is also possible, as described above, to determine whether an error modulation frequency occurs based on the individual modulation frequencies and to determine the error position based on the frequency band corresponding to the error modulation frequency.

[0060] Fig. 6 shows a block diagram of a device for detecting a fault of a transmission according to an exemplary embodiment of the present disclosure.

[0061] As in Fig. 6, the transmission failure detection device 100 according to an embodiment of the present disclosure includes a data obtaining unit 110, a data splitting unit 120, a characteristic value obtaining unit 130, and a failure determining unit 140.

[0062] In particular, the receiving unit 110 is configured to receive detection data of the transmission.

[0063] In one embodiment, the acquisition data may be vibration data or sound data. The acquisition data may, for example, be time-domain acquisition data.

[0064] The data division unit 120 is configured to divide the detection data into a plurality of groups of sub-band data.

[0065] In one embodiment, the data division unit 120 may divide the detection data into a plurality of groups of sub-band data of a plurality of frequency bands according to a predetermined octave within a predetermined frequency range.

[0066] In one example, this predetermined frequency range is a frequency range of 20 Hz to 20 kHz and this predetermined octave is a 1 / 3 octave.

[0067] The characteristic value obtaining unit 130 is configured to obtain a characteristic value of each group of subband data of the plurality of groups of subband data.

[0068] In one embodiment, the characteristic acquisition unit 130 may be configured to acquire the envelope of each group of subband data in the time domain to obtain envelope data of each group of subband data; perform a fast Fourier transform on the envelope data of each group of subband data to obtain frequency-domain subband data of each group of subband data; and obtain a modulation frequency corresponding to the frequency-domain subband data of each group of subband data. Here, the modulation frequency is a frequency having the maximum amplitude on an amplitude-frequency curve corresponding to the frequency-domain subband data.

[0069] Furthermore, in one embodiment, the characteristic value acquisition unit 130 may be further configured to acquire a modulation depth corresponding to the frequency-domain subband data of each subband data group. Here, the modulation depth is a sum of the amplitude of the modulation frequency on the above amplitude-frequency curve and the amplitude of the predetermined multiple frequency of the modulation frequency.

[0070] The fault determination unit 140 is configured to determine whether a fault occurs in the transmission based on all the characteristic values obtained.

[0071] In one embodiment, the fault determination unit 140 may be configured to determine whether an error modulation frequency is present in all obtained modulation frequencies, wherein the error modulation frequency is a modulation frequency that is identical to an error frequency in a predetermined error frequency set; and, if an error modulation frequency is present, to determine that a fault is occurring in the transmission.

[0072] In one embodiment, the error determination unit 140 may be configured to determine whether an error modulation frequency is present in all obtained modulation frequencies by determining a rotational speed of the transmission; detecting an error frequency set corresponding to the rotational speed; and determining whether an error modulation frequency is present in all obtained modulation frequencies that is identical to an error frequency in this error frequency set.

[0073] In one embodiment, the fault determination unit 140 may be further configured to determine, in the presence of an error modulation frequency, a frequency band corresponding to the error modulation frequency, wherein the frequency band is one of the plurality of frequency bands; and to determine the position at which the fault of the transmission occurs based on the frequency band.

[0074] Furthermore, in one embodiment, the error determination unit 140 may also be configured to determine the roughness of the detection data according to all obtained modulation frequencies and all obtained modulation depths, wherein the roughness indicates the degree of error of the transmission.

[0075] In other words, the device 100 for detecting a fault of a transmission according to an embodiment of the present disclosure can perform the above-mentioned with reference to Fig. 1 to Fig. 5 described methods for detecting a fault of a transmission according to an embodiment of the present disclosure.

[0076] The acquisition data, the division of the acquisition data, the preservation of the characteristic value and the determination of a fault of a gearbox were described above with reference to Fig. 1 to Fig. 5 and are not repeated here.

[0077] According to the device for detecting a failure of a transmission of the present disclosure, the failure state of the transmission can be determined by dividing the detection data into a plurality of groups of sub-band data and by the individual groups of sub-band data, whereby the accuracy of the failure detection of the transmission can be improved and the influence of noise on the failure detection of the transmission can be reduced.

[0078] According to an embodiment of the present disclosure, there is also provided a computer-readable medium having stored thereon instructions that, when executed by the processor, cause a processor to perform the above method for detecting a fault of a transmission according to an embodiment of the present disclosure.

[0079] It should be noted that the present invention is not limited to the specific configurations and processes described above and illustrated in the drawings. For the sake of brevity, a detailed description of the known methods is omitted here. In the above embodiments, some specific steps are described and shown as examples. However, the process flow of the present invention is not limited to the specific steps described and shown. Those skilled in the art may make various changes, modifications, and additions, or change the order of the steps, after understanding the essence of the present invention.

[0080] The functional blocks shown in the structural block diagram described above can be implemented as hardware, software, firmware, or a combination thereof. When implemented as hardware, the elements can be, for example, an electronic circuit, an application-specific integrated circuit (ASIC), corresponding firmware, a plug-in, a function card, etc. When implemented as software, the elements of the present invention are programs or sections of code used to perform the required tasks. The programs or sections of code can be stored on a machine-readable medium or transmitted over a transmission medium or communication link using a data signal carried in a carrier wave. "Machine-readable media" can include any media capable of storing or transmitting information.Examples of machine-readable media include electronic circuits, semiconductor storage devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical discs, hard disks, fiber optic media, radio frequency (RF) links, and so on. The code sections can be downloaded over a computer network such as the Internet, an intranet, or the like.

[0081] It should also be noted that the exemplary embodiments mentioned in the present invention describe some methods or systems based on a series of steps or means. However, the present invention is not limited to the order of the above-mentioned steps; that is, the steps may be performed in an order mentioned in the embodiments or in an order different from the order in the embodiments, or some steps may be performed simultaneously.

[0082] The above embodiments are only specific embodiments of the present invention. Those skilled in the art can clearly understand that, for the convenience and conciseness of description, the specific working process of the system, module, and unit described above may refer to the corresponding process in the above method embodiments and will not be repeated here. It is understood that the scope of the present invention is not limited thereto, and that any person skilled in the art can easily imagine various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be covered by the scope of the present invention.

Claims

[1] A method for detecting a fault of a transmission, comprising: Obtaining transmission acquisition data; Splitting the acquisition data into several groups of subband data; Obtaining a characteristic value of each group of subband data of the plurality of groups of subband data; and Determine whether a fault has occurred in the transmission based on all the parameters obtained. [2] The method of claim 1, wherein dividing the acquisition data into a plurality of groups of subband data comprises: Dividing the detection data into a plurality of groups of sub-band data of a plurality of frequency bands according to a predetermined octave within a predetermined frequency range. [3] The method of claim 2, wherein the acquisition data is acquisition data in a time domain, and wherein obtaining a characteristic value of each group of subband data of the plurality of groups of subband data comprises: detecting the envelope of each group of subband data in the time domain to obtain envelope data of each group of subband data; performing a fast Fourier transform on the envelope data of each group of subband data to obtain frequency-domain subband data of each group of subband data; and Obtaining a modulation frequency corresponding to the frequency-domain subband data of each group of subband data, the modulation frequency being a frequency having the maximum amplitude on an amplitude-frequency curve corresponding to the frequency-domain subband data. [4] The method of claim 3, wherein determining whether a fault occurs in the transmission based on all the characteristic values obtained comprises: Determining whether an error modulation frequency is present in all obtained modulation frequencies, wherein the error modulation frequency is a modulation frequency that is identical to an error frequency in a predetermined error frequency set, and Determine that a fault is occurring in the transmission when an error modulation frequency is present. [5] The method of claim 4, wherein determining whether an error modulation frequency is present in all obtained modulation frequencies comprises: Determining a speed of the transmission; Obtaining an error frequency set corresponding to the speed; and Determine whether in all received modulation frequencies there is an error modulation frequency that is identical to an error frequency in the error frequency set. [6] The method of claim 4, wherein the method further comprises: Determining a frequency band corresponding to the error modulation frequency in the presence of an error modulation frequency, wherein the frequency band is one of the plurality of frequency bands; and Determine a position based on the frequency band where the gearbox fault occurs. [7] The method of claim 3, wherein obtaining a characteristic value of each group of subband data of the plurality of groups of subband data further comprises: Obtaining a modulation depth corresponding to the frequency domain subband data of each group of subband data, the modulation depth being a sum of the amplitude of the modulation frequency on the amplitude-frequency curve and the amplitude of a predetermined multiple frequency of the modulation frequency. [8] The method of claim 7, wherein the method further comprises: Determining a roughness of the acquired data based on all obtained modulation frequencies and all obtained modulation depths, wherein the roughness indicates a degree of error of the transmission. [9] A method according to claim 8, wherein the roughness is expressed by the following equation: RVA=k×∑1Nfi×ΔLi where R VA is the roughness, k is a constant coefficient determined based on an operating condition of the gearbox, f i is a modulation frequency corresponding to the i-th group of subband data, ΔL i is a modulation depth corresponding to the i-th group of subband data, and N is a total number of groups of the plurality of groups of subband data, where i and N are each an integer and 1 ≤ i ≤ N. [10] Device for detecting a fault of a transmission, comprising: a data acquisition unit configured to acquire detection data of the transmission; a data division unit configured to divide the acquisition data into a plurality of groups of sub-band data; a characteristic value obtaining unit configured to obtain a characteristic value of each group of sub-band data of the plurality of groups of sub-band data; and a fault determination unit configured to determine, based on all received characteristic values, whether a fault occurs in the transmission. [11] The device according to claim 10, wherein the data dividing unit is arranged to divide the detection data into a plurality of groups of sub-band data of a plurality of frequency bands according to a predetermined octave within a predetermined frequency range. [12] The device according to claim 11, wherein the detection data is detection data in a time domain, wherein the characteristic value obtaining unit is configured to: detect the envelope of each group of subband data in the time domain to obtain envelope data of each group of subband data; performing a fast Fourier transform on the envelope data of each group of subband data to obtain frequency-domain subband data of each group of subband data; and to obtain a modulation frequency corresponding to the frequency-domain subband data of each group of subband data, the modulation frequency being a frequency having the maximum amplitude on an amplitude-frequency curve corresponding to the frequency-domain subband data. [13] The device according to claim 12, wherein the error determination unit is arranged to: to determine whether an error modulation frequency is present in all the obtained modulation frequencies, wherein the error modulation frequency is a modulation frequency that is identical to an error frequency in a predetermined error frequency set, and to determine that a fault is occurring in the transmission when an error modulation frequency is present. [14] The device according to claim 13, wherein the error determination unit is arranged to determine whether an error modulation frequency is present in all the obtained modulation frequencies by: the speed of the gearbox is determined; an error frequency set is obtained which corresponds to the speed; and it is determined whether in all received modulation frequencies there is an error modulation frequency that is identical to an error frequency in the error frequency set. [15] The device according to claim 13, wherein the error determination unit is further configured to: to determine a frequency band in the presence of an error modulation frequency, which corresponds to the error modulation frequency, wherein the frequency band is one of the plurality of frequency bands; and to determine a position at which the gearbox fault occurs based on the frequency band. [16] Device according to claim 12, wherein the characteristic value obtaining unit is further configured to: to obtain a modulation depth corresponding to the frequency domain subband data of each group of subband data, the modulation depth being a sum of the amplitude of the modulation frequency on the amplitude-frequency curve and the amplitude of a predetermined multiple frequency of the modulation frequency. [17] The device according to claim 16, wherein the error determination unit is further configured to: to determine a roughness of the acquired data based on all obtained modulation frequencies and all obtained modulation depths, whereby the roughness indicates the degree of error of the gearbox.

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