Apparatus and method for processing digital signal

Abstract

A device (10) for processing a digital signal (S9) comprises samples of a continuous signal sampled at a fixed sampling rate, representative of vibrations of a bearing comprising a stationary ring and a rotating ring concentrically rotatable with respect to the stationary ring, the device comprising:-a Farrow structure (15),-identification means (16) for identifying a digital signal (S9), -a Farrow structure (15) configured to identify, as a function of a rotational speed of the rotating ring, an instant at which the rotating ring has rotated from a predetermined rotational angle,-a control device (17) configured to determine paired control values from the determined instant and to control the Farrow structure (15) from the paired control values.

Description

Technical Field

[0001] The present invention relates to an apparatus for processing a digital signal and a method for processing a digital signal. Background Art

[0002] Condition monitoring algorithms, such as those detecting bearing faults (such as failure of the raceways within the bearing), require a constant rotational speed of the bearing to function properly.

[0003] Typically, condition monitoring algorithms perform spectral analysis on rotating bearings to detect faults at specific tones and harmonics.

[0004] The change in the rotational speed of the bearing during the signal measurement eliminates spectral tones and reduces the ability to identify frequencies and harmonics that may be associated with a fault (such as a bearing inner raceway fault or a bearing outer raceway fault). Summary of the invention

[0005] Therefore, the present invention aims to correct for the detrimental effects of rotational speed variations in order to perform spectral analysis.

[0006] According to an aspect, a method for processing a digital signal comprising samples of a continuous signal sampled at a fixed sampling rate, the continuous signal representing vibrations of a bearing comprising a stationary ring and a rotating ring rotatable concentrically relative to the stationary ring is proposed.

[0007] The method includes:

[0008] - identifying the moment when the rotating ring has rotated from a predetermined rotation angle,

[0009] - determining pairs of control values ​​from the determined instants, and

[0010] - controlling the Farrow structure from the pair of control values ​​such that the Farrow structure applies a time varying sampling rate conversion from a fixed sampling rate to a time varying sampling to the digital signal, the digital signal sampled with the time varying sampling being a result signal.

[0011] This method allows the use of existing constant rotation speed algorithms under conditions of varying rotation speed, thereby eliminating the need for repeated attempts to obtain constant speed data acquisition.

[0012] Taking into account the rotational speed of the rotating ring allows taking into account auxiliary speed measurements.

[0013] Advantageously, determining pairs of control values ​​from the determined moments comprises decomposing each determined moment into a first value equal to an integer part of the determined moment and a second value equal to a fractional part of the determined moment, each pair of control values ​​comprising the first value and the second value.

[0014] Preferably, the Farrow structure comprises:

[0015] - M+1 sub-filters (C_M(z), ..., C_1(z), C_0(z)) that filter the samples, M+1 memory banks,

[0016] - M multipliers with variable gain, and M adders, M being an integer,

[0017] The input of each memory bank is connected to the output of a sub-filter,

[0018] The output of the Mth memory bank is connected to the input of the Mth multiplier, the first input of the Mth adder is connected to the output of the Mth multiplier, the second input of the Mth adder is connected to the M-1th memory bank,

[0019] For P varying between 1 and M-1, the input of the Pth multiplier is connected to the output of the P+1th adder, the first input of the Pth adder is connected to the output of the Pth multiplier, and the second input of the Pth adder is connected to the P-1 memory bank.

[0020] Among them, the control Farrow structure includes for each pair of control values:

[0021] selecting a stored data item of each memory bank stored at an address equal to the first value, and

[0022] The M multipliers are configured such that variable gains of the M multipliers are equal to a second value.

[0023] Advantageously, determining the rotational speed of the moving ring comprises determining a continuous estimate of the rotational speed.

[0024] Preferably, the time is identified from the rotation angle and / or speed of the rotating ring.

[0025] According to an aspect, a device for processing a digital signal comprising samples of a continuous signal sampled at a fixed sampling rate, the continuous signal representing vibrations of a bearing comprising a stationary ring and a rotating ring rotatable concentrically relative to the stationary ring is proposed.

[0026] The equipment includes:

[0027] -Farrow structure,

[0028] - recognition means configured to recognize, based on the rotation angle and / or speed of the rotating ring, the moment when the rotating ring has rotated from a predetermined rotation angle,

[0029] - a control device configured to determine a pair of control values ​​from the determined time instants and to control the Farrow structure from the pair of control values ​​such that the Farrow structure applies a time-varying sampling rate conversion from a fixed sampling rate to a time-varying sampling on the digital signal, the digital signal sampled with the time-varying sampling being a result signal.

[0030] Advantageously, the control means are configured to resolve each determined moment into a first value equal to the integer part of the determined moment and a second value equal to the fractional part of the determined moment, each pair of control values ​​comprising the first value and the second value.

[0031] Preferably, the Farrow structure comprises:

[0032] - M+1 sub-filters (C_M(z), ..., C_1(z), C_0(z)) that filter the samples, M+1 memory banks,

[0033] - M multipliers with variable gain, and M adders, M being an integer,

[0034] The input of each memory bank is connected to the output of a sub-filter,

[0035] The output of the Mth memory bank is connected to the input of the Mth multiplier, the first input of the Mth adder is connected to the output of the Mth multiplier, the second input of the Mth adder is connected to the M-1th memory bank,

[0036] For P varying between 1 and M-1, the input of the Pth multiplier is connected to the output of the P+1th adder, the first input of the Pth adder is connected to the output of the Pth multiplier, and the second input of the Pth adder is connected to the P-1 memory bank.

[0037] The control device is configured such that for each control value:

[0038] - selecting a stored data item of each memory bank stored at an address equal to the first value, and

[0039] - configuring the M multipliers such that the variable gains of the M multipliers are equal to a second value.

[0040] According to one aspect, a bearing arrangement is provided.

[0041] The bearing equipment includes:

[0042] - a bearing provided with a stationary ring and a rotating ring which can rotate concentrically relative to the stationary ring,

[0043] - a first sensor configured to measure the vibrations of said inner or outer ring and configured to deliver a continuous signal,

[0044] - first means configured to determine the rotation speed of the rotating ring,

[0045] a sampler configured to sample the continuous signal at a fixed sampling rate and configured to deliver a digital signal comprising the samples, and

[0046] - A device as defined above, configured to process the digital signal as a function of the rotation speed of the rotating ring delivered by the first means.

[0047] Preferably, the first device comprises a second sensor configured to measure the rotation speed of the rotating ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Other advantages and features of the invention will appear on examination of the detailed description of embodiments, which are in no way limiting, and of the accompanying drawings, in which:

[0049] Figure 1 A rotating machine according to the invention is schematically shown;

[0050] Figure 2 An example of a device for processing a digital signal according to the present invention is schematically shown;

[0051] Figure 3 An example of a Farrow structure is schematically shown;

[0052] Figure 4 The method of determining the coefficients of the Farrow structure is schematically shown,

[0053] Figure 5 A method for processing a digital signal according to the present invention is schematically shown;

[0054] Figure 6 schematically shows an example of the rotation speed of a rotating ring according to the time delivered by the first device according to the invention;

[0055] Figure 7 schematically shows an example of a moment according to time identified by the identification device according to the present invention;

[0056] Figure 8 schematically illustrates an example of a signal transmitted by a Farrow structure according to the present invention; and

[0057] Fig. 9 An example of a frequency spectrum delivered by a spectrum analysis device for a steady rotational speed of a bearing is schematically shown when the bearing speed is reduced during measurements according to the prior art and according to the invention. DETAILED DESCRIPTION

[0058] refer to Figure 1 , which schematically shows a partial longitudinal section of the machine 1 .

[0059] The machine 1 comprises a housing 2 and a shaft 3 supported in the housing 2 by rolling bearings 4, such as roller bearings or ball bearings.

[0060] The rolling bearing 4 is provided with a rotating ring 5 mounted on the shaft 3 and a stationary ring 6 mounted into a hole of the housing 2. The stationary ring 6 radially surrounds the rotating ring 5. The rotating ring 5 and the stationary ring 6 rotate concentrically relative to each other.

[0061] The rolling bearing 4 is also provided with a row of rolling elements 7, which are radially interposed between the inner and outer raceways of the rotating ring 5 and the stationary ring 6. In the illustrated example, the rolling elements 7 are balls. Alternatively, the rolling bearing may include other types of rolling elements 7, such as rollers. In the illustrated example, the rolling bearing includes a row of rolling elements 7. Alternatively, the rolling bearing may include multiple rows of rolling elements.

[0062] A first sensor 8 is mounted in the housing 2 to measure vibrations of the bearing 4 which are subject to variations in rotational speed.

[0063] The first sensor 8 may be mounted on a hole in the housing 2 .

[0064] In a variant, the first sensor 8 could be mounted elsewhere on the machine, for example near the stationary ring 6 or near the casing 2 .

[0065] The first sensor 8 delivers a continuous signal S8 representative of the vibrations of the bearing 4 to the input of the sampler 9 .

[0066] The sampler 9 includes a plurality of consecutive samples x of the continuous signal S8 sampled at a fixed sampling rate. p The digital signal S9 is passed to a first input 101 of the device 10 for processing the digital signal S9, and p is an integer.

[0067] The first means 11 are used to determine the rotation speed of the rotating ring 5 and to transmit the rotation speed of the rotating ring 5 to the second input 102 of the device 10 .

[0068] The first device 11 comprises, for example, a second sensor for measuring the rotation speed of the rotating ring 5, or estimating the rotation speed of the rotating ring 5, which can be done, for example, based on a set of pulses generated at fixed angular rotation intervals of a shaft or wheel attached to the rotating ring 5 via a fixing device, or based on a similar tachometer-related method.

[0069] The bearing 4 , the first sensor 8 , the sampler 9 , the device 10 and the first arrangement 11 form a bearing arrangement.

[0070] The memory (not shown) may store the output signal S9 and transfer the output signal S9 to the device 10 .

[0071] The first output 103 of the device 10 is connected to first implementing means 12 implementing at least one constant speed time domain algorithm, for example realizing an envelope fault detection algorithm, as a function of the first output signal S103 delivered by the device 10 on the first output 103 .

[0072] The second output 104 of the device 10 is connected to second implementation means 13 which implement at least one constant speed spectrum orientation algorithm, for example a Fast Fourier Transform paired with a fault frequency detection method, according to the second output signal S104 delivered by the device 10 on the second output 104 .

[0073] The first and second implementation means 12, 13 are each constituted by a processing unit implementing the algorithm, for example.

[0074] The processing unit 14 implements the first sensor 8 , the sampler 9 , the device 10 and the first means 11 .

[0075] Figure 2 An example of a device 10 is schematically shown.

[0076] The device 10 comprises a Farrow structure 15 , which is known from document US Pat. No. 4,866,647, a recognition device 16 , a control device 17 and a spectrum analysis device 18 .

[0077] The Farrow structure 15 comprises an input 151 connected to the input 101 of the device 10 , an output 152 connected to the first output 103 of the device 10 and to an input 181 of the spectrum analysis means 18 , and comprises a control input 153 connected to the output 172 of the control means 17 .

[0078] An output 182 of the spectrum analysis device 18 is connected to the second output 104 of the apparatus 10 .

[0079] The spectrum analysis means 18 comprises a spectrum analysis algorithm ALGO1 , such as a Fast Fourier Transform algorithm.

[0080] An input 161 of the recognition means 16 is connected to the second input 102 of the device 10 , and an output of the recognition means 16 is connected to an input 171 of the control means 17 .

[0081] The Farrow structure 15 iteratively adjusts the inter-sample delay of the measurement data (resampling).

[0082] The Farrow structure 15 is based on an N-th order finite impulse response FIR filter, whose coefficients h(n,Δ) can be changed by a control variable Δ equal to the inter-sample position or delay of the Farrow structure, n being an integer between 0 and N.

[0083] The filter coefficients h(n,Δ) are formed by a polynomial of the control variable Δ.

[0084] The coefficient h(n,Δ) is equal to:

[0085]

[0086] Where M is a set of polynomial orders whose values ​​are chosen by performance requirements. N and M are integers. The matrix C represents each coefficient C of each M-order polynomial of each filter coefficient h(n,Δ) mn Each C mn The coefficients implement an (n+1)-th order filter, which implements a delay of Δ, denoted as h(n,Δ).

[0087] Coefficient C mn It can be represented as a coefficient matrix C of dimension (M+1)×(N+1).

[0088]

[0089] The transfer function H(z,Δ) of the Farrow structure 15 is given by:

[0090]

[0091] in,

[0092]

[0093] Here, m varies between 0 and M, and n varies between 0 and N.

[0094] Item C m (z) refers to a sub-filter of the Farrow structure 15, and the Farrow structure 15 includes M+1 sub-filters.

[0095] The Farrow structure 15 delivers a signal S152 at its output 152 .

[0096] Figure 3 An example of a Farrow structure 15 is schematically shown.

[0097] Farrow structure 15 includes C M (z),…,C1(z),C0(z), M+1 sub-filters, M+1 memory banks 19, 20, 21, M multipliers 22, 23 each with a variable gain G22, G23, and M adders 24, 25.

[0098] Each multiplier 22, 23 comprises an input, an output delivering the signal received on the input multiplied by a variable gain G22, G23, and a control input receiving the variable gain value.

[0099] Each adder 24, 25 comprises first and second inputs, and an output conveying the sum of the first and second inputs.

[0100] Each sub-filter C M (z),…,C1(z),C0(z) includes inputs 26, 27, 28 connected to the input 151 of the Farrow structure and outputs 29, 30, 31 connected to the inputs of different memory banks 19, 20, 21.

[0101] The output of the Mth memory bank 19 is connected to the input of the Mth multiplier 22 .

[0102] A first input of the Mth adder is connected to the output of the Mth multiplier 22, and a second input of the Mth adder is connected to the M-1th memory bank.

[0103] For P varying between 1 and M-1, P is an integer, the input of the Pth multiplier is connected to the output of the P+1th adder, the first input of the Pth adder is connected to the output of the Pth multiplier, and the second input of the Pth adder is connected to the P-1th memory bank.

[0104] For example, Figure 3 As shown, the output of the multiplier 23 is connected to a second input of the adder 25 .

[0105] The output of the last adder 25 is connected to the output 152 of the Farrow structure 15 .

[0106] Each memory bank 19 , 20 , 21 is connected to a control input 153 to select which stored data item of each memory bank 19 , 20 , 21 is transferred to the multipliers G22 , G23 and the adders 24 , 25 .

[0107] The control inputs of the M variable gains G22, G23 are connected to the control input 153 of the Farrow structure 15 to control the value of each variable gain to have the same value.

[0108] Since the sub-filter C M The structures of C(z),…,C1(z),C0(z) are the same, so only sub-filter C is described in detail. M (z) structure.

[0109] Sub-filter C M (z) includes a series of N delay elements D 33, N+1 second multipliers 35, 36, 37, 38 and a second summer 39.

[0110] The N+1 second multipliers 35, 36, 37, 38 will be in the sub-filter C MN+1 sequential samples x of the signal received at input 26 of (z) n Multiply by N+1 filter coefficients C M0 To C MN , and multiply the sequential samples x n Passed to the second summer 39.

[0111] The second summer 39 multiplies the N+1 consecutive samples x by the N+1 second multipliers 35, 36, 37, 38. n Add them and pass the sum to the input of memory bank 19.

[0112] Figure 4 The coefficients C of the coefficient matrix C of dimension (M+1)×(N+1) are shown in the prior art. m Examples of known methods.

[0113] At step 40 , the order N of the Farrow structure 15 and the order M of the polynomial are defined according to the accuracy required by the device 10 .

[0114] At any single moment, the control value Δ of each multiplier G22, G23 is the same.

[0115] In another embodiment, the control value Δ for each multiplier G22, G23 may vary on a sample-by-sample basis and is represented as Δ n . Fractional delay Δ n The value of is controlled by a control unit of the device 10 (not shown) and is applied to each input sample x according to n The control unit also selects the required fractional delay according to the fractional delay Δ n to select which data sample to extract from the memory 19, 20, 21 to achieve the necessary integer component of the required delay.

[0116] To provide a continuous range of delays, the Farrow architecture relies on polynomial curve fitting based on a set of fixed-delay reference filters. For example, assuming a set of 8 reference filters each implementing a fixed delay, the fixed delay Δ of each reference filter can be selected between -0.5 and 0.5 in increments of 0.125, such that the integer j varies between 0 and 7, Δ0 = -0.5, .Δ1 = -0.375, ... Δ7 = +0.375.

[0117] In step 41, a set of functions g is calculated for each value of j and a given value of n j (n,Δ j ).

[0118] Function g j can be, for example, equal to:

[0119]

[0120] In step 42, the coefficients C of the coefficient matrix C are determined. mn , so that for a given value of n and a desired delay value Δ, the filter coefficients h(n,Δ) are fitted by C mn The function g defined j (n,Δ j ) for all values ​​of Δ between -0.5 and +0.5.

[0121] Figure 5 An example implementation of the device 10 is shown.

[0122] Assume that the coefficient matrix C is defined and the subfilter C M (z),…,C1(z),C0(z) are parameterized according to the coefficient matrix C.

[0123] During a step 50 , the sampler 9 delivers a sample x comprising the continuous signal S8 delivered from the sensor 8 . p The digital signal S9 is transmitted to the first device 11 , and a continuous estimate of the rotation speed of the rotating ring 5 is delivered.

[0124] Figure 6 An example of a rotation speed Ω of the rotating ring 5 as a function of the time t delivered by the first device 11 is shown.

[0125] During a step 51 , the recognition means 16 recognize the moment when the rotating ring has been rotated from a predetermined rotation angle (for example π / 4).

[0126] The recognition device 16 recognizes the time as a function of the rotation speed Ω of the rotating ring 5 , for example by integrating the rotation speed Ω.

[0127] In a variant, the recognition means 16 recognize the time as a function of the rotation angle θ of the rotating ring 5 .

[0128] Figure 7 An example of moments identified by the identification means 16 as a function of time t is shown, the moments being represented by diamonds, between two adjacent moments the rotating ring 5 having rotated by an angle of rotation equal to π / 4.

[0129] During a step 52 , the control device 17 determines a pair of control values ​​(Δi, Δf) as a function of the time determined by the recognition device 16 .

[0130] The control device 17 decomposes each moment into a first value equal to the integer part Δi of the determined moment and a second value equal to the fractional part Δf of the determined moment, each pair of control values ​​comprising the first value Δi and the second value Δf.

[0131] The delay Δ is such that:

[0132] Δ=Δi+Δf (6)

[0133] During step 53, the control device 17 controls the Farrow structure 15 according to the pair of control values ​​(Δi, Δf) so that the Farrow structure 14 is coupled to the sample x p The digital signal S9 applies a time-varying sampling rate conversion from a fixed sampling rate to a time-varying sampling rate and delivers a resulting signal comprising a digital signal sampled at a time-varying sampling interval at an output 152 of the Farrow device 15, thereby achieving speed variation compensation.

[0134] The resulting signal is a first output signal S152 delivered at an output 152 of the Farrow device 15 .

[0135] The temporal variation of the resulting samples depends on the value of the pair of control values ​​(Δi, Δf) delivered by the control device 17 .

[0136] The control means 17 selects the storage data item of each memory bank 10, 20, 21 stored at an address equal to the first value Δi and controls the M multipliers 22, 23 such that the variable gain of the M multipliers is equal to the second value Δf.

[0137] Figure 8 An example of a signal S152 delivered at the output 152 of the Farrow device 15 is shown.

[0138] The points P1 to P8 are determined by the Farrow device 15 so that the samples of the signal S152 (points P1 to P8 ) conform to a predetermined rotation angle, for example π / 4.

[0139] The method returns to step 50, where the next sample x is delivered by the sampler 9. p .

[0140] Fig. 9 The vibration spectrum transmitted by the sensor 8 at a stable rotational speed of the bearing 4 is shown by graph SP1, and the spectrum is shown by graph SP2 when the rotational speed of the bearing 4 undergoes a 3% speed change during data collection compared to the stable rotational speed when the sensor 8 measures the rotational speed.

[0141] A graph SP3 is plotted which represents the frequency spectrum delivered at the second output 103 of the device 10 when the rotational speed of the bearing 4 undergoes a speed variation of 3% during data collection after speed variation compensation has been applied. This is very close to a steady rotational speed.

[0142] In graph SP1 , three tones T10 , T20 , T30 are easily identifiable at respective frequencies F1 , F2 , F3 .

[0143] Tone T10 is the fundamental frequency, and tones T20 and T30 are two harmonics. The sharp feature of graph SP1 assumes the presence of a constant speed spectrum.

[0144] In the graph SP2, the three tones T11, T21, T31 with reduced peaks are barely identifiable. It is impossible to determine their exact positions, so the constant speed time domain algorithm implemented by the first implementation device 11 and the constant speed spectrum-oriented algorithm implemented by the second implementation device 12 may not be able to determine whether the three tones T11, T21, T31 are of interest. The skewness value of the graph SP1 is less than the reference skewness value.

[0145] In graph SP3, three tones T12, T22, T33 are easily identifiable at respective frequencies F1, F2, F3. The sharp features of the original constant velocity spectrum are restored.

[0146] The device 10 reconstructs the tones T12, T22, T32 and the peaks of their frequencies F1, F2, F3.

[0147] When the rotational speed varies, the device 10 allows the use of existing constant rotational speed algorithms, thereby eliminating the need to repeat data acquisition attempts due to speed variations.

[0148] The ability to allow the use of data acquired at speed variations allows the range of use cases to be expanded and generally allows for more efficient use of data in bearing condition monitoring. As an example, suppressing repeated attempts at data acquisition allows for saving power to the apparatus comprising the sensor 8, sampler 9 and device 10, for example wireless powering comprising a power source such as a battery.

[0149] The temporal variation of the resulting samples depends on the value of the pair of control values ​​(Δi, Δf) delivered by the control device 17 .

[0150] The control means 17 selects the storage data item of each memory bank 10, 19, 20, 21 stored at an address equal to the first value Δi and controls the M multipliers 22, 23 such that the variable gain of the M multipliers is equal to the second value Δf.

[0151] The first value Δi and the second value Δf allow for coarse and fine delays, respectively, providing accurate compensation for rotational speed variations.

[0152] Taking into account the rotation speed of the rotating ring 5 allows taking into account an auxiliary speed measurement.

Claims

1. A method for processing samples (x) of a continuous signal (S8) sampled at a fixed sampling rate p ), the continuous signal representing the vibration of a bearing (4), the bearing comprising a stationary ring (6) and a rotating ring (5) capable of coaxially rotating relative to the stationary ring (6), the method comprising: - identifying the moment when the rotating ring (5) has rotated from a predetermined rotation angle, - determining pairs of control values ​​from the determined instants, and - controlling the Farrow structure (15) from the pair of control values ​​such that the Farrow structure (15) applies a time varying sampling rate conversion from a fixed sampling rate to a time varying sampling to the digital signal, the digital signal sampled at said time varying sampling being the resultant signal.

2. The method according to claim 1, wherein: Determining pairs of control values ​​from the determined moments includes decomposing each determined moment into a first value equal to an integer portion of the determined moment and a second value equal to a fractional portion of the determined moment, each pair of control values ​​including the first value and the second value.

3. The method according to claim 2, wherein: The Farrow structure (15) comprises: - M+1 sub-filters (C_M(z), ..., C_1(z), C_0(z)) that filter the samples, M+1 memory banks (19, 20, 21), - M multipliers (22, 23) with variable gains (G22, G23), and M adders (24, 25), M being an integer, The input of each memory bank (19, 20, 21) is connected to the output of a sub-filter (C_M(z), ..., C_1(z), C_0(z)), The output of the Mth memory bank is connected to the input of the Mth multiplier, the first input of the Mth adder is connected to the output of the Mth multiplier, the second input of the Mth adder is connected to the M-1th memory bank, For P varying between 1 and M-1, the input of the Pth multiplier is connected to the output of the P+1th adder, the first input of the Pth adder is connected to the output of the Pth multiplier, and the second input of the Pth adder is connected to the P-1 memory bank. The control Farrow structure (15) includes, for each pair of control values: selecting a stored data item of each memory bank (19, 20, 21) stored at an address equal to a first value, and The M multipliers (22, 23) are configured so that the variable gains (G22, G23) of the M multipliers are equal to a second value.

4. The method according to any one of claims 1 to 3, wherein: Determining the rotational speed of the moving ring (5) comprises determining a continuous estimate of the rotational speed.

5. The method according to any one of claims 1 to 4, wherein: The time is identified based on the rotation angle and / or speed of the rotating ring (5).

6. A method for processing samples (x) comprising a continuous signal (S8) sampled at a fixed sampling rate p ), the continuous signal representing the vibration of a bearing (4), the bearing comprising a stationary ring (6) and a rotating ring (5) capable of coaxially rotating relative to the stationary ring (6), the device comprising: -Farrow structure (15), - an identification device (16) configured to identify the moment when the rotating ring (5) has rotated from a predetermined rotation angle based on the rotation angle and / or speed of the rotating ring (5), - a control device (17) configured to determine a pair of control values ​​from the determined time instants and to control the Farrow structure (15) from the pair of control values ​​so that the Farrow structure (15) applies a time-varying sampling rate conversion from a fixed sampling rate to a time-varying sampling on the digital signal, the digital signal sampled with the time-varying sampling being a result signal.

7. The device according to claim 6, wherein: The control device (17) is configured to decompose each determined moment into a first value equal to an integer part of the determined moment and a second value equal to a fractional part of the determined moment, each pair of control values ​​comprising the first value and the second value.

8. The device according to claim 7, wherein: The Farrow structure includes: - M+1 sub-filters (C_M(z), ..., C_1(z), C_0(z)) that filter the samples, M+1 memory banks (19, 20, 21), - M multipliers (22, 23) with variable gains (G22, G23), and M adders (24, 25), M being an integer, The input of each memory bank (19, 20, 21) is connected to the output of a sub-filter (C_M(z), ..., C_1(z), C_0(z)), The output of the Mth memory bank is connected to the input of the Mth multiplier, the first input of the Mth adder is connected to the output of the Mth multiplier, the second input of the Mth adder is connected to the M-1th memory bank, For P varying between 1 and M-1, the input of the Pth multiplier is connected to the output of the P+1th adder, the first input of the Pth adder is connected to the output of the Pth multiplier, and the second input of the Pth adder is connected to the P-1 memory bank. The control device (17) is configured to, for each control value: - selecting the stored data item of each memory bank (19, 20, 21) stored at an address equal to the first value, and - configuring the M multipliers (22, 23) so that the variable gains (G22, G23) of the M multipliers are equal to a second value.

9. A bearing device, comprising: - a bearing (4) provided with a stationary ring (6) and a rotating ring (5) which can rotate concentrically relative to the stationary ring (5), - a first sensor (8) configured to measure the vibration of the inner ring (5) or the outer ring (6) and configured to deliver a continuous signal (S8), - first means, configured to determine the rotation speed of the rotating ring (5), a sampler (9) configured to sample the continuous signal (S8) at a fixed sampling rate and to deliver a digital signal (S9) comprising the samples, and - Device (10) according to any one of claims 5 to 8, configured to process the digital signal (S9) as a function of the rotation speed of the rotating ring delivered by the first means.

10. The bearing device according to claim 9, wherein: The first device includes a second sensor configured to measure a rotational speed of the rotating ring.

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