Lubricating oil viscosity measurement method, system, and electronic device

Abstract

Embodiments of the present application provide a lubricating oil viscosity measurement method, system and electronic equipment, and relate to the field of lubricating oil viscosity measurement. The method controls the piezoelectric ceramic resonator to self-excitation vibration in the lubricating oil to be measured at a preset frequency, obtains a vibration attenuation waveform collected by a data collection circuit, the vibration attenuation waveform includes a plurality of positive half waves, calculates the integral area of each positive half wave, and calculates the area ratio of two adjacent positive half waves based on the integral area. According to the area ratio and the preset viscosity calculation formula, the viscosity of the lubricating oil to be measured is calculated. The vibration attenuation waveform generated by the piezoelectric ceramic resonator in the lubricating oil can quickly calculate the viscosity of the lubricating oil to be measured according to the viscosity calculation formula.

Description

Technical Field

[0001] This invention relates to the field of lubricating oil viscosity measurement, and more specifically, to a lubricating oil viscosity measurement method, system, and electronic device. Background Technology

[0002] The viscosity of lubricating oil is a crucial indicator of its lubrication performance, and changes in viscosity directly affect the normal operation of an engine. Current technologies for lubricating oil viscosity detection primarily employ capillary methods, rotation methods, falling-body methods, and vibration methods. However, these methods generally suffer from problems such as complex equipment, demanding testing conditions, offline-only measurement capabilities, and long processing times, making them unsuitable for online real-time detection. Therefore, developing a signal processing method capable of rapid online detection of oil viscosity is of great significance. Summary of the Invention

[0003] In view of this, the object of the present invention is to provide a lubricating oil viscosity measurement method, system and electronic device to at least partially improve the above-mentioned problems.

[0004] To achieve the above objectives, the technical solutions adopted in the embodiments of the present invention are as follows: In a first aspect, embodiments of the present invention provide a method for measuring the viscosity of lubricating oil, applied to a controller of a lubricating oil viscosity measurement system, the lubricating oil viscosity measurement system further including a piezoelectric ceramic resonator and a data acquisition circuit, comprising: The piezoelectric ceramic resonator is controlled to self-excite and vibrate at a preset frequency in the lubricating oil to be measured. The vibration attenuation waveform acquired by the data acquisition circuit is obtained; wherein the vibration attenuation waveform includes multiple positive half-waves; Calculate the integral area of ​​each positive half-wave, and calculate the area ratio of two adjacent positive half-waves based on the integral area of ​​each positive half-wave. The viscosity of the lubricating oil to be measured is calculated based on the area ratio and the preset viscosity calculation formula.

[0005] Optionally, calculating the integral area of ​​each of the positive half-waves includes: Linear interpolation is performed on the vibration attenuation waveform to determine the zero-crossing point of the vibration attenuation waveform; Based on each of the zero-crossing points, multiple positive half-waves are determined; The integral area of ​​each positive half-wave is calculated by using the trapezoidal area approximation method.

[0006] Optionally, the step of performing linear interpolation on the vibration attenuation waveform to determine the zero-crossing point of the vibration attenuation waveform includes: In the vibration attenuation waveform, any two adjacent coordinate points are selected as two sampling points; wherein, the voltage values ​​of the two sampling points are positive and negative, respectively; Based on the coordinates of the two sampling points, determine the equation of the straight line passing through the two sampling points; Based on the linear equation, the zero-crossing point of the vibration attenuation waveform between the two sampling points is solved.

[0007] Optionally, the step of calculating the integral area of ​​each of the positive half-waves using the trapezoidal area approximation method to obtain the integral area of ​​each of the positive half-waves includes: For each positive half-wave, the positive half-wave is divided into multiple adjacent sampling point segments, and each sampling point segment is constructed into a trapezoid. Calculate the area of ​​each trapezoid; The integral area of ​​the positive half-wave is obtained by summing the areas of all the trapezoids.

[0008] Optionally, after the step of acquiring the vibration attenuation waveform acquired by the data acquisition circuit, the method further includes: The vibration attenuation waveform is processed to remove the mean, so that the vibration attenuation waveform is centered on the time axis.

[0009] Optionally, after the step of acquiring the vibration attenuation waveform acquired by the data acquisition circuit, the method further includes: Perform a Fast Fourier Transform on the vibration attenuation waveform to obtain the spectrum; Identify the dominant frequency in the spectrum and set the low-frequency components to the left of the dominant frequency to zero to obtain the filtered spectrum; The filtered spectrum is subjected to inverse fast Fourier transform to obtain the vibration attenuation waveform after filtering.

[0010] Optionally, the method further includes the step of obtaining the viscosity calculation formula, which includes: The test waveforms of the piezoelectric ceramic resonator vibrating in several lubricating oils of known viscosity were obtained; Calculate the area ratio of two adjacent positive half-waves of each test waveform; The viscosity calculation formula is obtained by performing polynomial fitting on each of the known viscosity values ​​and each of the area ratio values.

[0011] Optionally, the lubricating oil viscosity measurement system further includes a self-excited oscillation circuit, wherein controlling the piezoelectric ceramic resonator to self-excite oscillate at a preset frequency in the lubricating oil to be measured includes: The self-excited oscillation circuit provides an excitation signal to the piezoelectric ceramic resonator, causing the resonator to undergo forced vibration in the lubricating oil to be measured. After the excitation signal stops, the piezoelectric ceramic resonator is allowed to enter a free decay vibration state.

[0012] Secondly, embodiments of the present invention provide a lubricating oil viscosity measurement system, including a controller, a piezoelectric ceramic resonator, and a data acquisition circuit; The piezoelectric ceramic resonator is used to be immersed in the lubricating oil to be measured and to generate vibration. The data acquisition circuit is used to acquire the vibration attenuation waveform generated by the piezoelectric ceramic resonator in the lubricating oil to be measured; The controller is configured to execute any of the methods described above.

[0013] Thirdly, embodiments of the present invention provide an electronic device, including a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor executes the computer program to implement the method described in any of the above-mentioned embodiments.

[0014] The present invention provides a method, system, and electronic device for measuring the viscosity of lubricating oil. By using the self-excited vibration of a piezoelectric ceramic resonator in the lubricating oil, combined with the acquisition and processing of the vibration attenuation waveform, the viscosity of the lubricating oil to be measured can be quickly calculated according to the viscosity calculation formula, realizing rapid online measurement of lubricating oil viscosity and significantly improving detection efficiency.

[0015] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic structural block diagram of an electronic device provided in an embodiment of the present invention; Figure 2 A schematic flowchart of a lubricating oil viscosity measurement method provided in an embodiment of the present invention; Figure 3 A schematic diagram of a vibration attenuation waveform provided in an embodiment of the present invention; Figure 4 A flowchart illustrating step S230 provided in an embodiment of the present invention; Figure 5Another flowchart illustrating step S230 provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of a positive half-wave segmentation provided in an embodiment of the present invention; Figure 7 Another flowchart illustrating step S230 provided in an embodiment of the present invention; Figure 8 A schematic diagram of a vibration attenuation waveform offset provided in an embodiment of the present invention; Figure 9 A schematic diagram of a process for obtaining a viscosity calculation formula is provided in an embodiment of the present invention; Figure 10 This is a schematic structural block diagram of a lubricating oil viscosity measurement system provided in an embodiment of the present invention.

[0018] Icons: 100 - Electronic device; 101 - Memory; 102 - Communication interface; 103 - Processor; 104 - Communication bus; 400 - Lubricating oil viscosity measurement system; 410 - Piezoelectric ceramic resonator; 420 - Data acquisition circuit; 430 - Controller. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0021] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this invention, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0022] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0023] As described in the background section, existing technologies for lubricating oil viscosity testing often employ capillary methods, rotation methods, falling body methods, and vibration methods. However, these methods generally suffer from problems such as complex equipment, high requirements for testing conditions, reliance on offline measurements, and long testing times, making it difficult to meet the needs of online real-time testing. For example: 1. Capillary viscometer A capillary viscometer is an instrument designed to measure viscosity based on Hagen-Poiseuille's law. Its working principle is as follows: assuming the radius of the capillary is R and its length is L, and the pressure difference across the capillary is ΔP, the liquid is subjected to an external force of 2πR... Under the influence of P, the fluid flows at a constant velocity in the capillary, and its volumetric flow rate is Q. The following relationships exist between the various quantities:

[0024] Where R is the radius of the capillary (m), ΔP is the flow pressure difference (Pa), and Q is the fluid flow rate (m³·s⁻¹). 1) L is the capillary length (m).

[0025] 2. Rotational viscometer The principle of a rotational viscometer is based on the fact that when an object immersed in a fluid (such as a cylinder, cone, plate, sphere, or other rigid body) rotates, or when these objects are stationary while the surrounding fluid rotates, these objects will be subjected to the viscous torque of the fluid. The magnitude of the viscous torque is proportional to the viscosity of the fluid. The viscosity of the liquid is determined by measuring the viscous torque and the rotational speed of the rotating body.

[0026] 3. Free-fall viscometer When an object falls through a fluid, the higher the viscosity of the fluid, the slower the object falls. Therefore, the falling speed can be used to compare the viscosity of the fluid. Suppose a rigid ball of radius r falls at a velocity v into a test tube containing a viscous fluid of viscosity η. The time it takes for the ball to fall a certain distance is related to the viscosity of the liquid as follows: η=K(ρ0-ρ)t Where ρ0 is the density of the sphere, ρ is the density of the fluid, and K is a constant that depends on the radius r of the sphere and the diameter of the test tube in the viscometer. Therefore, by first obtaining the constant using a viscosity standard solution, and then measuring the falling time over a certain distance and the density of the liquid being tested, the viscosity can be determined.

[0027] 4. Vibration viscometer Vibratory viscometers operate based on the shear stress principle. The sensor's sensitive element, acted upon by a force generator, undergoes torsional oscillations within the fluid. Due to changes in fluid viscous damping, its oscillation amplitude varies. Energy supplied externally to compensate for the energy consumed by viscous damping maintains the sensitive element's oscillation at its resonant frequency and constant amplitude. The relationship between the supplied energy and the product of the fluid's viscosity and density is as follows:

[0028] Where η is the kinematic viscosity of the fluid being tested; ρ is the density of the fluid being tested; and E is the energy supplied.

[0029] Based on the above, embodiments of the present invention provide a method, system, and electronic device for measuring lubricating oil viscosity. The method involves controlling a piezoelectric ceramic resonator to self-excite at a preset frequency within the lubricating oil to be measured, and using a data acquisition circuit to acquire multiple positive half-wave waveform signals generated during the vibration attenuation process. Subsequently, the controller performs integral area calculation on each positive half-wave, and based on the area ratio of two adjacent positive half-waves, combined with a preset viscosity calculation formula, quickly and accurately obtains the viscosity value of the lubricating oil.

[0030] To implement the process steps and functions of the various examples of this invention, please refer to [link / reference]. Figure 1 , Figure 1 This is a schematic structural block diagram of an electronic device provided in an embodiment of the present invention. The electronic device 100 includes a memory 101 and a processor 103, which are electrically connected directly or indirectly to each other to achieve data transmission or interaction. For example, these components can be electrically connected to each other through one or more communication buses 104 or signal lines. The memory 101 can be used to store software programs and modules, and the processor 103 executes the software programs and modules stored in the memory 101, thereby performing various functional applications and data processing.

[0031] Electronic device 100 can be, but is not limited to, a personal computer (PC), a server, a distributed computer, etc. It is understood that electronic device 100 is not limited to a physical server, but can also be a virtual machine on a physical server, a virtual machine built on a cloud platform, or any other computer that can provide the same functionality as the server or virtual machine. The operating system of electronic device 100 can be, but is not limited to, Windows, Linux, etc.

[0032] The memory 101 may be, but is not limited to, random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), etc.

[0033] The communication connection between the electronic device 100 and external devices is achieved through at least one communication interface 102 (which can be wired or wireless).

[0034] Processor 103 may be an integrated circuit chip with signal processing capabilities. In implementation, the steps of this embodiment can be completed by integrated logic circuits in the hardware of processor 103 or by instructions in software form. Processor 103 may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0035] Understandable. Figure 1 The structure shown is for illustrative purposes only; the electronic device 100 may also include components that are more advanced than those shown. Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown. Figure 1The components shown can be implemented using hardware, software, or a combination thereof.

[0036] The following is an exemplary description of the lubricating oil viscosity measurement method provided by the present invention. See [link to documentation]. Figure 2 This method is applied to the controller of a lubricating oil viscosity measurement system, which also includes a piezoelectric ceramic resonator and a data acquisition circuit. The controller can be used for the aforementioned... Figure 1 The electronic device 100 shown, the method includes as follows Figure 2 The following steps are described: S210: Controls the piezoelectric ceramic resonator to self-excite at a preset frequency in the lubricating oil to be measured.

[0037] Alternatively, the lubricating oil to be measured can be other types of oil.

[0038] S220: Acquire the vibration attenuation waveform acquired by the data acquisition circuit; wherein, the vibration attenuation waveform includes multiple positive half-waves.

[0039] S230: Calculate the integral area of ​​each positive half-wave, and calculate the area ratio of two adjacent positive half-waves based on each integral area.

[0040] S240: Calculate the viscosity of the lubricating oil to be measured based on the area ratio and the preset viscosity calculation formula.

[0041] The principle of this method for measuring viscosity using a resonant plate is that when a vibrating object is placed in lubricating oil, its amplitude will continuously decrease due to the presence of viscosity. The viscosity of the lubricating oil can be obtained by measuring the vibration state of the object.

[0042] First, the piezoelectric ceramic resonator is immersed in the lubricating oil to be measured during the measurement process. The controller controls the piezoelectric ceramic resonator to vibrate at a preset frequency in the lubricating oil, for example, 100 Hz. After self-excited vibration, the piezoelectric ceramic resonator begins to oscillate and decay due to damping in the lubricating oil. The data acquisition circuit collects the vibration decay waveform. After acquiring the vibration decay waveform, the controller processes and calculates the viscosity of the lubricating oil to be measured based on the vibration decay waveform.

[0043] See Figure 3 For vibration attenuation waveforms, there are multiple positive half-waves, i.e., the parts with positive amplitude. The integral area of ​​each positive half-wave is calculated. After obtaining the integral area of ​​each positive half-wave, the ratio of the areas of two adjacent positive half-waves is calculated. For example, the integral area of ​​the first positive half-wave is compared with the integral area of ​​the second positive half-wave, the integral area of ​​the second positive half-wave is compared with the integral area of ​​the third positive half-wave, and so on.

[0044] The area ratio used to calculate the viscosity of the lubricating oil to be measured can be any one of the area ratios calculated above, or it can be the average of multiple area ratios. For example, the ratio of the integral area of ​​the first positive half-wave to the integral area of ​​the second positive half-wave can be substituted into the viscosity calculation formula to calculate the viscosity of the lubricating oil to be measured. Alternatively, the average of the ratios of the integral areas of the first and second positive half-waves, and the ratios of the integral areas of the second and third positive half-waves can be taken and substituted into the viscosity calculation formula to calculate the viscosity of the lubricating oil to be measured.

[0045] This method utilizes the self-excited vibration of a piezoelectric ceramic resonator in lubricating oil, combined with the acquisition and processing of vibration attenuation waveforms, to quickly calculate the viscosity of the lubricating oil to be measured according to the viscosity calculation formula.

[0046] Because the data acquisition has a certain frequency, not every zero-crossing point will be included in the acquired data; that is, data with an amplitude of 0 may not be acquired. For example, the amplitude acquired in the first second might be -10V, and the amplitude acquired in the second second might be 10V. There is a zero-crossing point in between that data was not acquired. Therefore, it is necessary to calculate the zero-crossing point before calculating the integral area of ​​the positive half-wave. For an example of accurately calculating the integral area of ​​the positive half-wave, see [link to example]. Figure 4 The steps for calculating the integral area of ​​each positive half-wave may include the following: S231: Perform linear interpolation on the vibration attenuation waveform to determine the zero-crossing point of the vibration attenuation waveform.

[0047] S232: Based on each zero-crossing point, multiple positive half-waves are determined.

[0048] S233: The integral area of ​​each positive half-wave is calculated by using the trapezoidal area approximation method.

[0049] Linear interpolation (i.e., inserting an estimated value between two adjacent sampling points) allows for a more accurate approximation of the true waveform. Then, based on the interpolated waveform, the precise location of the zero-crossing point is detected. Between two adjacent zero-crossing points, if the waveform is positive, it constitutes a "positive half-wave." For example, starting from one zero-crossing point, the waveform rises and then falls to the next zero-crossing point; if this entire waveform is positive, it constitutes a positive half-wave. This allows the entire vibration signal to be decomposed into multiple independent positive half-wave segments. The integral area of ​​each positive half-wave is calculated, i.e., the area between the waveform and the time axis, serving as a measure of the energy of that waveform segment. Since the actual signal consists of discrete sampling points, the trapezoidal area approximation method is used for numerical integration to obtain the integral area of ​​each positive half-wave.

[0050] To quickly determine the zero-crossing point, in this embodiment of the invention, only the difference between the zero-crossing points needs to be calculated. See [link to relevant documentation]. Figure 5Step S231 above may include the following steps: S2311: Select any two adjacent coordinate points in the vibration attenuation waveform as two sampling points; wherein, the voltage values ​​of the two sampling points are positive and negative, respectively.

[0051] S2312: Determine the equation of the straight line passing through the two sampling points based on their coordinates.

[0052] S2313: Based on the linear equation, solve for the zero-crossing point of the vibration attenuation waveform between two sampling points.

[0053] Select any two adjacent sampling points in the vibration decay waveform, with the voltage values ​​at these two points being positive and negative, respectively. This means that there is a zero-crossing process between these two points, where the voltage changes from positive to negative (or from negative to positive).

[0054] For these two sampling points, we can derive a straight line equation based on them, and then determine the zero-crossing point on the line. For example, if the two sampling points are A(x1,y1) and B(x2,y2), we can then derive the slope k and intercept b of the straight line equation:

[0055]

[0056] The equation of the line is:

[0057] The y-coordinate of the point passing through zero is 0. Therefore, from y=0, we can find the x-coordinate, and finally obtain the coordinates of the point passing through zero as ( ,0).

[0058] For calculating the integral area of ​​a positive half-wave, we can use the concept of differentiation to transform the area of ​​the curve into the area of ​​triangles and trapezoids, such as... Figure 6 As shown, the areas on the left and right sides are triangles, and the area in the middle is a trapezoid. See [link to possible implementation]. Figure 7 The above step S233 may include: S2331: For each positive half-wave, divide the positive half-wave into multiple adjacent sampling point segments, and construct each sampling point segment into a trapezoid.

[0059] S2332: Calculate the area of ​​each trapezoid.

[0060] S2333: Sum the areas of all trapezoids to obtain the integral area of ​​the positive half-wave.

[0061] For each positive half-wave, including multiple acquired discrete points and two calculated zero-crossing points, any two adjacent points constitute a sampling point segment. See [link to relevant documentation]. Figure 6The sampling point segment is constructed into a trapezoid with the time axis. For the two triangles on the left and right, they are regarded as trapezoids with a top side of 0. Each trapezoid is composed of the height (voltage value) of two points and the time (or horizontal axis) difference between them.

[0062] For each constructed trapezoid, its area is calculated using the trapezoid area formula. All trapezoid areas are compiled into an area list, where each area represents the approximate integral value of the waveform signal within that time period. Finally, all trapezoid areas are summed to obtain the integral area of ​​the positive half-wave.

[0063] See Figure 8 In vibration signals, DC offset refers to the signal's average value not being zero, meaning the entire waveform is shifted upwards or downwards by a fixed voltage value (DC component). Ideally, the vibration signal should be symmetrical about the time axis (zero point), but due to various reasons, the actual acquired signal often deviates from zero. Therefore, in one possible implementation, after step S220, the method may further include the following steps: S221: Perform mean removal processing on the vibration decay waveform to center the vibration decay waveform on the time axis.

[0064] The voltage values ​​of all sampling points in the vibration attenuation waveform are averaged to obtain an offset voltage. The voltage value of each sampling point is subtracted from the offset voltage to obtain the processed sampling points.

[0065] Since the acquired waveforms may have poor repeatability and large fluctuations, filtering can be performed on the waveforms to reduce errors caused by these fluctuations. In one possible implementation, after step S220, the method may further include the following step: S222: Perform a fast Fourier transform on the vibration attenuation waveform to obtain the spectrum.

[0066] S223: Identify the dominant frequency in the spectrum and set the low-frequency components to the left of the dominant frequency to zero to obtain the filtered spectrum.

[0067] S224: Perform an inverse fast Fourier transform on the filtered spectrum to obtain the filtered vibration attenuation waveform.

[0068] The vibration decay waveform data is a discrete time series signal (such as voltage changing with time). The fast Fourier transform is used to convert the time domain signal into a frequency domain signal to obtain the spectrum of the vibration decay waveform, that is, the amplitude (or energy) distribution of each frequency component.

[0069] In this spectrum, the dominant frequency component is identified, typically the frequency with the highest energy, often a preset frequency, such as 100Hz as mentioned above. The amplitudes of all frequency components to the left of the dominant frequency (i.e., frequencies lower than the dominant frequency) are set to 0. An inverse fast Fourier transform is performed on the spectrum after low-frequency suppression to obtain a filtered time-domain vibration signal, in which low-frequency components have been removed. After filtering, the vibration attenuation waveform is smoother and less volatile.

[0070] In an optional embodiment, the method may further include the step of obtaining a viscosity calculation formula, see [link to relevant documentation]. Figure 9 This step includes: S310: Obtain test waveforms of piezoelectric ceramic resonators vibrating in lubricating oils of known viscosities.

[0071] S320: Calculate the area ratio of two adjacent positive half-waves of each test waveform.

[0072] S330: Perform polynomial fitting on each known viscosity and each area ratio to obtain the viscosity calculation formula.

[0073] First, prepare several lubricating oils with known viscosities. Then, calculate the area ratio of two adjacent positive half-waves for each lubricating oil using steps S210 to S230 described above. For example, we obtain 100 sets of data, each set including viscosity and area ratio.

[0074] By performing a polynomial fit on these data, the viscosity calculation formula can be obtained. For example, we obtain the data as (x... i y i Fit a quadratic polynomial:

[0075] To minimize the fitting error, we establish a least-squares objective and define the sum of squared errors:

[0076] Taking the partial derivatives and setting them to 0, and then taking the partial derivatives with respect to a, b, and c, we obtain the canonical system of equations:

[0077] This is a set of three simultaneous linear equations. Gaussian elimination can be used to solve for the coefficients a, b, and c, ultimately yielding the viscosity calculation formula.

[0078] Where y is viscosity and x is area ratio.

[0079] The vibration of the piezoelectric ceramic resonator can be controlled by a self-excited oscillation circuit. Therefore, the lubricating oil viscosity measurement system may also include a self-excited oscillation circuit, and step S210 above may also include: S211: The piezoelectric ceramic resonator is provided with an excitation signal through a self-excited oscillation circuit, so that the resonator generates forced vibration in the lubricating oil to be measured.

[0080] S212: After the excitation signal stops, the piezoelectric ceramic resonator is allowed to enter a free decay vibration state.

[0081] The piezoelectric ceramic resonator is continuously vibrated at the resonant frequency by the periodic excitation signal generated by the self-excited oscillation circuit. When the excitation signal is stopped, the vibration of the resonator gradually decays due to the damping effect of the lubricating oil. The piezoelectric ceramic outputs a voltage signal during the decay process, which reflects the law of its vibration amplitude decaying with time, and thus the vibration decay waveform can be obtained.

[0082] Furthermore, embodiments of the present invention also provide a lubricating oil viscosity measurement system, see [link to relevant documentation]. Figure 10 The lubricating oil viscosity measurement system 400 includes a controller 430, a piezoelectric ceramic resonator 410, and a data acquisition circuit 420.

[0083] The piezoelectric ceramic resonator 410 is used to immerse the lubricating oil to be measured and generate vibration.

[0084] The data acquisition circuit 420 is used to acquire the vibration attenuation waveform generated by the piezoelectric ceramic resonator in the lubricating oil to be measured.

[0085] The controller 430 is used to perform the above-described method for measuring the viscosity of lubricating oil.

[0086] In summary, the lubricating oil viscosity measurement method, system, and electronic device provided by the embodiments of the present invention achieve rapid measurement of lubricating oil viscosity by controlling the self-excited vibration of a piezoelectric ceramic resonator in lubricating oil, acquiring the vibration decay waveform, calculating the positive half-wave integral area and its area ratio, and combining it with the viscosity calculation formula. By performing signal processing techniques such as linear interpolation to determine the zero-crossing point, trapezoidal area approximation integration, mean removal processing, and FFT filtering on the waveform, the measurement accuracy and stability are improved.

[0087] In the embodiments provided by this invention, it should be understood that the disclosed apparatus and methods can also be implemented in other ways. The apparatus embodiments described above are merely illustrative; for example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code, which contains one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0088] In addition, the functional modules in the various embodiments of the present invention can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0089] If the functionality is implemented as a software module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a computer-readable storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0090] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0091] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A method for measuring the viscosity of lubricating oil, characterized in that, A controller for a lubricating oil viscosity measurement system, the lubricating oil viscosity measurement system further including a piezoelectric ceramic resonator and a data acquisition circuit, including: The piezoelectric ceramic resonator is controlled to self-excite and vibrate at a preset frequency in the lubricating oil to be measured. The vibration attenuation waveform acquired by the data acquisition circuit is obtained; wherein the vibration attenuation waveform includes multiple positive half-waves; Calculate the integral area of ​​each positive half-wave, and calculate the area ratio of two adjacent positive half-waves based on the integral area of ​​each positive half-wave. The viscosity of the lubricating oil to be measured is calculated based on the area ratio and the preset viscosity calculation formula. The steps for obtaining the viscosity calculation formula include: The test waveforms of the piezoelectric ceramic resonator vibrating in several lubricating oils of known viscosity were obtained; Calculate the area ratio of two adjacent positive half-waves of each test waveform; The viscosity calculation formula is obtained by performing polynomial fitting on each of the known viscosity values ​​and each of the area ratio values.

2. The method according to claim 1, characterized in that, The calculation of the integral area of ​​each of the positive half-waves includes: Linear interpolation is performed on the vibration attenuation waveform to determine the zero-crossing point of the vibration attenuation waveform; Based on each of the zero-crossing points, multiple positive half-waves are determined; The integral area of ​​each positive half-wave is calculated by using the trapezoidal area approximation method.

3. The method according to claim 2, characterized in that, The step of performing linear interpolation on the vibration attenuation waveform to determine the zero-crossing point of the vibration attenuation waveform includes: In the vibration attenuation waveform, any two adjacent coordinate points are selected as two sampling points; wherein, the voltage values ​​of the two sampling points are positive and negative, respectively; Based on the coordinates of the two sampling points, determine the equation of the straight line passing through the two sampling points; Based on the linear equation, the zero-crossing point of the vibration attenuation waveform between the two sampling points is solved.

4. The method according to claim 2, characterized in that, The step of calculating the integral area of ​​each positive half-wave using the trapezoidal area approximation method to obtain the integral area of ​​each positive half-wave includes: For each positive half-wave, the positive half-wave is divided into multiple adjacent sampling point segments, and each sampling point segment is constructed into a trapezoid. Calculate the area of ​​each trapezoid; The integral area of ​​the positive half-wave is obtained by summing the areas of all the trapezoids.

5. The method according to claim 1, characterized in that, After the step of acquiring the vibration attenuation waveform acquired by the data acquisition circuit, the method further includes: The vibration attenuation waveform is processed to remove the mean, so that the vibration attenuation waveform is centered on the time axis.

6. The method according to claim 1 or 5, characterized in that, After the step of acquiring the vibration attenuation waveform acquired by the data acquisition circuit, the method further includes: Perform a Fast Fourier Transform on the vibration attenuation waveform to obtain the spectrum; Identify the dominant frequency in the spectrum and set the low-frequency components to the left of the dominant frequency to zero to obtain the filtered spectrum; The filtered spectrum is subjected to inverse fast Fourier transform to obtain the vibration attenuation waveform after filtering.

7. The method according to claim 1, characterized in that, The lubricating oil viscosity measurement system further includes a self-excited oscillation circuit, wherein controlling the piezoelectric ceramic resonator to self-excite and oscillate at a preset frequency in the lubricating oil to be measured includes: The self-excited oscillation circuit provides an excitation signal to the piezoelectric ceramic resonator, causing the resonator to undergo forced vibration in the lubricating oil to be measured. After the excitation signal stops, the piezoelectric ceramic resonator is allowed to enter a free decay vibration state.

8. A lubricating oil viscosity measurement system, characterized in that, Includes a controller, a piezoelectric ceramic resonator, and a data acquisition circuit; The piezoelectric ceramic resonator is used to be immersed in the lubricating oil to be measured and to generate vibration. The data acquisition circuit is used to acquire the vibration attenuation waveform generated by the piezoelectric ceramic resonator in the lubricating oil to be measured; The controller is configured to perform the method as described in any one of claims 1 to 7.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the method according to any one of claims 1 to 7.

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