Method and system for converting regularly sampled data to periodically sampled data

Abstract

The application discloses a kind of conversion method and system of timing sampling data to whole cycle sampling data, and the present application obtains the timing sampling time based on the keying position moment when obtaining keying position moment by timing sampling, according to the timing sampling time and the vibration signal of timing sampling, obtains the vibration signal of whole cycle sampling, effectively realizes the conversion of timing sampling data to whole cycle sampling data, can make timing sampling acquisition system realize whole cycle sampling function, and the present application can be realized by software, without changing the hardware structure of timing sampling acquisition system, without increasing hardware investment.

Description

Technical Field

[0001] This invention relates to a method and system for converting timed sampling data into full-cycle sampling data, belonging to the field of rotating machinery fault diagnosis. Background Technology

[0002] Fault diagnosis of rotating machinery relies on the acquisition of vibration signals. Currently, commonly used signal acquisition methods include timed sampling and full-cycle sampling. Compared to timed sampling, full-cycle sampling can reduce leakage and picket-fence effects during the Fourier transform of rotating machinery vibration signals, enabling accurate identification of amplitude and phase after the Fourier transform. Signals obtained using full-cycle sampling can more accurately identify and diagnose typical speed-related faults such as dynamic imbalance and misalignment. However, because full-cycle sampling requires the use of technologies such as phase-locked loops, its hardware implementation is costly and difficult. Therefore, most current acquisition systems only implement timed sampling and do not have full-cycle sampling functionality. Summary of the Invention

[0003] This invention provides a method and system for converting timed sampling data into whole-cycle sampling data, which solves the problems disclosed in the background art.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0005] A method for converting timed sampling data into integer-cycle sampling data includes:

[0006] Acquire the key phase signal and vibration signal by timed sampling;

[0007] Based on the key phase signal, obtain the key phase position time;

[0008] The timing of the sampling is obtained based on the key phase position time and the rotor motion equation;

[0009] Based on the timing of the sampling and the vibration signal sampled at regular intervals, the vibration signal sampled for the entire cycle is obtained.

[0010] Based on the key phase signal, obtain the key phase position time, including:

[0011] The position and time of the bond phase are obtained using the local radius method based on the bond phase signal.

[0012] The local radius method is defined as follows: if a point in the key phase signal satisfies a preset rule and no other point satisfies the preset local radius of that point, then the time corresponding to that point is the key phase position time.

[0013] The preset rule is: the signal value of the previous point is less than the threshold, and the signal value of the current point is greater than the threshold.

[0014] Based on the timing of the sampling and the sampling vibration signal, the vibration signal sampled for the entire cycle is obtained, including:

[0015] Based on the sampling time and the sampling vibration signal, the spline interpolation method is used to obtain the vibration signal of the whole cycle sampling.

[0016] A system for converting timed sampling data to integer-cycle sampling data includes:

[0017] Signal acquisition module: Acquires key phase signals and vibration signals sampled at regular intervals;

[0018] Key phase position time acquisition module: acquires the key phase position time based on the key phase signal;

[0019] Sampling time acquisition module: Based on the key phase position time and rotor motion equation, the sampling time is obtained;

[0020] Full-cycle sampling signal acquisition module: Based on the time of the timed sampling and the vibration signal of the timed sampling, acquire the vibration signal of the full cycle sampling.

[0021] Key phase position time acquisition module: Based on the key phase signal, the key phase position time is acquired using the local radius method.

[0022] The local radius method is defined as follows: if a point in the key phase signal satisfies a preset rule and no other point satisfies the preset local radius of that point, then the time corresponding to that point is the key phase position time.

[0023] The preset rule is: the signal value of the previous point is less than the threshold, and the signal value of the current point is greater than the threshold.

[0024] Full-cycle sampling signal acquisition module: Based on the time of the timed sampling and the vibration signal of the timed sampling, the spline interpolation method is used to obtain the vibration signal of the full cycle sampling.

[0025] A computer-readable storage medium storing one or more programs, the one or more programs including instructions that, when executed by a computing device, cause the computing device to perform a method for converting timed sampled data into full-cycle sampled data.

[0026] A computing device includes one or more processors, one or more memories, and one or more programs, wherein the one or more programs are stored in the one or more memories and configured to be executed by the one or more processors, and the one or more programs include instructions for performing a method for converting timed sampled data into full-cycle sampled data.

[0027] The beneficial effects achieved by this invention are as follows: This invention obtains the key phase position time by sampling the key phase signal at regular intervals, obtains the sampling time based on the key phase position time, and obtains the vibration signal of the whole cycle sampling according to the sampling time and the vibration signal of the sampling time. This effectively realizes the conversion of the sampling data of the timing period to the sampling data of the whole cycle, enabling the timing sampling acquisition system to realize the sampling function of the whole cycle. Moreover, this invention can be implemented by software without changing the hardware structure of the timing sampling acquisition system and without increasing hardware investment. Attached Figure Description

[0028] Figure 1 A flowchart of the conversion method;

[0029] Figure 2 The key phase signal and vibration signal are sampled at regular intervals;

[0030] Figure 3 This is the first example of the local radius method;

[0031] Figure 4 The second example of the local radius method

[0032] Figure 5 Example of a timed sampling signal;

[0033] Figure 6 This is an example of a converted integer-cycle sampled signal. Detailed Implementation

[0034] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0035] like Figure 1 As shown, a method for converting timed sampling data into integer-cycle sampling data includes the following steps:

[0036] Step 1: Acquire the timed sampling of the key phase signal and vibration signal;

[0037] Step 2: Obtain the key phase position time based on the key phase signal;

[0038] Step 3: Obtain the timing sampling time based on the key phase position time and the rotor motion equation;

[0039] Step 4: Obtain the vibration signal of the whole cycle based on the sampling time and the sampling vibration signal.

[0040] The above method obtains the key phase position time by sampling the key phase signal at regular intervals, obtains the sampling time based on the key phase position time, and obtains the vibration signal of the whole cycle sampling based on the sampling time and the sampling vibration signal at regular intervals. This effectively realizes the conversion of the sampling data at regular intervals to the sampling data of the whole cycle, enabling the sampling acquisition system to realize the sampling function of the whole cycle. Moreover, this method can be implemented by software without changing the hardware structure of the sampling acquisition system and without increasing hardware investment.

[0041] Assuming there is only one bond phase point in the circumferential direction, the timing sampling during the variable speed process is as follows: Figure 2 As shown:

[0042] 1) The signal array obtained from the key phase signal is: x = {x1, x2, ..., x...} N}, where N is an integer representing the number of sampling times;

[0043] 2) The signal array for any other measuring point is: This represents the vibration signal collected at sampling time N by measuring point j;

[0044] 3) The time interval for periodic sampling is δ.

[0045] Assuming that the angular acceleration of the rotor remains constant between any three consecutive key phase points (i.e., key phase positions), the rotor motion equations can satisfy:

[0046] θ(t)=b0+b1t+b2t 2

[0047] Here, θ(t) is the rotor's equation of motion, i.e., the relationship between the rotor's rotation angle and time, with parameters b0, b1, and b2 forming a column vector.

[0048] For each revolution of the rotor, the number of synchronous full-cycle sampling points is C (C is a positive integer, usually a positive power of 2). Therefore, the rotor angle array corresponding to the full-cycle sampling points is:

[0049] For the key phase signal, the local radius method is used to obtain the key phase position time. Based on the key phase position time and the rotor motion equation, the timing sampling time is obtained. Based on the timing sampling time and the timing sampled vibration signal, the spline interpolation method is used to obtain the vibration signal sampled for the entire cycle.

[0050] The local radius method is defined as follows: if a point in the bond phase signal satisfies a preset rule and no other point satisfies the preset local radius of that point, then the time corresponding to that point is the bond phase position time. The preset rule is: the signal value of the previous point is less than a threshold, and the signal value of the point itself is greater than a threshold.

[0051] To obtain the bond phase position time (i.e., the time when the bond phase point occurs), a threshold Thr is artificially set. If the preceding point of the signal is less than Thr, and the following point is greater than Thr, and no similar situation occurs within a specified time range (local radius), then we consider the time corresponding to the following point to be the bond phase position time. Figure 3 and 4 For example, with a local radius of 2, a correct identification is... Figure 3 In this example, if a current value (point 612) is less than Thr and the next point (point 613) is greater than Thr, then point 613 is identified as a key phase point. Furthermore, if there is no second key phase point within a range centered on point 613, then point 613 is a valid key phase signal. For incorrect key phase identification, see [link to example]. Figure 4 If another first-phase bond (615 points) is identified within a radius of 2 centered on the first identified bond phase point, then the 615th point is discarded and is not considered a first-phase bond identification.

[0052] The specific process of the above conversion method can be as follows:

[0053] 11) Obtain the bond phase signal threshold: Thr = 0.5·(max(x)-min(x))+mean(x);

[0054] 12) Initialization: The one-dimensional array key at the key phase time is an empty array, i = 0 is initialized, and the effective radius r = Const(positive integer, constant);

[0055] 13) Rising edge detection

[0056]

[0057] 14) Rising edge validity check (delete incorrect key phase positions in the key phase array), store the valid key phases in a new array Newkey, and assign them to key again (the newly generated key array stores the indices corresponding to the valid key phase points);

[0058] The size of the key array is M

[0059]

[0060] 15) Check if the size of array key is greater than 2. If it is true, continue; otherwise, go to 110.

[0061] 16) Generate the bond phase position time array T = δ·key;

[0062] 17) Initialize calculation conditions:

[0063] Column vectors:

[0064] Array Ast: An empty array used to store the timing sampling time corresponding to each integer sampling point within a single rotation cycle;

[0065] Array At: An empty array used to store the timing sampling time corresponding to the whole cycle sampling points within multiple consecutive rotation cycles, serving as a contiguous buffer array for the As array;

[0066] 18)

[0067] 19) Generate the time array τ = δ·[0,1,...,N-1] for timed sampling;

[0068] 110) Based on the time array and the measurement point signal, the sampled value corresponding to the At array is obtained by spline interpolation.

[0069] Figure 5 For timed sampling signals, Figure 6 For based on Figure 5 The signal in the sample is the integer-cycle sampled signal obtained by the above method.

[0070] For the currently widely used timed sampling acquisition systems, the above method realizes the conversion from timed sampling data to whole-cycle sampling data, which only improves the software of the existing system. In terms of software algorithms: when searching for the bond phase position, the local radius method is used to achieve accurate and effective identification of the bond phase position; when determining the whole-cycle resampling time point, the rotor motion equation adopts the quadratic function method to achieve efficient positioning of the resampling time point; when sampling in the whole cycle, the spline function method is used to achieve accurate interpolation of the sampling points.

[0071] This method offers significant economic and technical advantages, including reduced hardware costs for the data acquisition system, lower hardware investment, and flexible software configuration. Currently, it has been applied to the SSJ-9000 turbine unit condition monitoring and analysis system at NARI Hydropower Company and has achieved good results in the commercial operation of several hydropower stations.

[0072] Based on the same technical solution, this invention also discloses a software system for the above method, a system for converting timed sampling data into integer cycle sampling data, comprising:

[0073] Signal acquisition module: Acquires key phase signals and vibration signals that are sampled at regular intervals.

[0074] Key phase position time acquisition module: Based on the key phase signal, the key phase position time is acquired using the local radius method.

[0075] The local radius method is defined as follows: if a point in the bond phase signal satisfies a preset rule and no other point satisfies the preset local radius of that point, then the time corresponding to that point is the bond phase position time. The preset rule is: the signal value of the previous point is less than a threshold, and the signal value of the point itself is greater than a threshold.

[0076] Full-cycle sampling signal acquisition module: Based on the time of the timed sampling and the vibration signal of the timed sampling, the spline interpolation method is used to obtain the vibration signal of the full cycle sampling.

[0077] Based on the same technical solution, the present invention also discloses a computer-readable storage medium for storing one or more programs, wherein the one or more programs include instructions that, when executed by a computing device, cause the computing device to perform a method for converting timed sampling data into integer-cycle sampling data.

[0078] Based on the same technical solution, the present invention also discloses a computing device, including one or more processors, one or more memories, and one or more programs, wherein the one or more programs are stored in the one or more memories and configured to be executed by the one or more processors, and the one or more programs include instructions for performing a method for converting timed sampling data into full-cycle sampling data.

[0079] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0080] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0081] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0082] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0083] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of the claims of the present invention pending approval.

Claims

1. A method for converting timed sampling data into integer-cycle sampling data, characterized in that, include: Acquire the key phase signal and vibration signal by timed sampling; Based on the bond phase signal, the bond phase position time is obtained using the local radius method. The local radius method is defined as follows: if a point in the bond phase signal satisfies a preset rule and no other point within the preset local radius satisfies the preset rule, then the time corresponding to that point is the bond phase position time. The preset rule is: the signal value of the previous point is less than a threshold, and the signal value of the current point is greater than the threshold. The timing of the sampling is obtained based on the key phase position time and the rotor motion equation; Based on the sampling time and the sampling vibration signal, the spline interpolation method is used to obtain the vibration signal of the whole cycle sampling.

2. A system for converting timed sampling data into integer-cycle sampling data, characterized in that, include: Signal acquisition module: Acquires key phase signals and vibration signals sampled at regular intervals; Key phase position time acquisition module: Based on the key phase signal, the key phase position time is obtained using the local radius method; wherein, the local radius method is that if a point in the key phase signal satisfies a preset rule, and no other point within the preset local radius of that point satisfies the preset rule, then the time corresponding to that point is the key phase position time; the preset rule is: the signal value of the previous point is less than a threshold, and the signal value of the current point is greater than the threshold; Sampling time acquisition module: Based on the key phase position time and rotor motion equation, the sampling time is obtained; Full-cycle sampling signal acquisition module: Based on the time of the timed sampling and the vibration signal of the timed sampling, the spline interpolation method is used to obtain the vibration signal of the full cycle sampling.

3. A computer-readable storage medium for storing one or more programs, characterized in that: The one or more programs include instructions that, when executed by a computing device, cause the computing device to perform the method according to claim 1.

4. A computing device, characterized in that, include: One or more processors, one or more memories, and one or more programs, wherein the one or more programs are stored in the one or more memories and configured to be executed by the one or more processors, the one or more programs including instructions for performing the method according to claim 1.

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