A torsional vibration testing method, device, equipment, medium and program product

Abstract

This invention discloses a torsional vibration testing method, apparatus, equipment, medium, and program product. The method includes: acquiring pulse signals generated when the spindle drive system of a flatbed sewing machine rotates under preset working conditions, and generating a spindle speed signal based on the pulse signals; the preset working conditions include at least an unloaded working condition and a loaded working condition; processing the speed signal to obtain a corresponding target angle signal, and performing spectral analysis on the target angle signal to obtain a spectral analysis result of the spindle torsional vibration; and determining the torsional vibration test result of the flatbed sewing machine spindle drive system based on the spectral analysis result. These technical features solve the problem that existing flatbed sewing machine spindle torsional vibration testing lacks a unified standard and standardized evaluation system, making accurate verification and evaluation impossible.

Description

Technical Field

[0001] This invention relates to the field of computer technology, and in particular to a torsional vibration testing method, apparatus, equipment, medium, and program product. Background Technology

[0002] Torsional vibration is a reciprocating vibration in an angular direction caused by elastic deformation when a rotating shaft system transmits power. It is one of the main causes of fatigue failure in transmission components. In the design and manufacture of rotating machinery, the measurement and control of torsional vibration is an indispensable key technology.

[0003] Currently, the testing, analysis, and evaluation methods for torsional vibration of the main shaft transmission system in the flatbed sewing machine industry are still in their infancy. There is a lack of unified testing standards and standardized evaluation systems, which makes it impossible to accurately verify and effectively evaluate the torsional vibration performance during the development of the main shaft transmission system and related components of the flatbed sewing machine. It is also difficult to objectively judge whether the matching of torsional vibration damping mechanisms such as flexible couplings is reasonable. Summary of the Invention

[0004] This invention provides a torsional vibration testing method, apparatus, equipment, medium, and program product, which solves the problem that existing flatbed sewing machine spindle torsional vibration testing lacks a unified standard and standardized evaluation system, making accurate verification and evaluation impossible.

[0005] In a first aspect, embodiments of the present invention provide a torsional vibration testing method, comprising: Under preset working conditions, the pulse signal generated when the main shaft transmission system of the flat sewing machine rotates is collected, and the main shaft speed signal is generated based on the pulse signal. The preset working conditions include at least no-load working conditions and loaded working conditions. The rotational speed signal is processed to obtain the corresponding target angle signal, and the target angle signal is subjected to spectrum analysis to obtain the spectrum analysis results of the spindle torsional vibration. The torsional vibration test results of the main shaft drive system of the flat sewing machine were determined based on the spectrum analysis results.

[0006] Secondly, embodiments of the present invention provide a torsional vibration testing device, comprising: The signal acquisition module is used to acquire the pulse signal generated when the main shaft transmission system of the flat sewing machine rotates under preset working conditions, and generate the main shaft speed signal based on the pulse signal. The preset working conditions include at least no-load working conditions and loaded working conditions. The spectrum analysis module is used to process the rotational speed signal to obtain the corresponding target angle signal, and to perform spectrum analysis on the target angle signal to obtain the spectrum analysis results of the spindle torsional vibration. The torsional vibration test module is used to determine the torsional vibration test results of the main shaft transmission system of the flat sewing machine based on the spectrum analysis results.

[0007] Thirdly, embodiments of the present invention provide an electronic device, including: At least one processor; and A memory that is communicatively connected to at least one processor; wherein, The memory stores a computer program that can be executed by at least one processor, such that the at least one processor is able to execute the torsional vibration testing method provided in the first aspect embodiment described above.

[0008] Fourthly, embodiments of the present invention provide a computer-readable storage medium storing computer instructions that are used to cause a processor to execute a torsional vibration testing method provided in the first aspect of the embodiments described above.

[0009] Fifthly, embodiments of the present invention provide a computer program product, the computer program product including a computer program, which, when executed by a processor, implements a torsional vibration testing method provided in the first aspect of the embodiments described above.

[0010] The technical solution of this invention involves acquiring pulse signals generated when the main shaft transmission system of a flat sewing machine rotates under preset working conditions, and generating a main shaft speed signal based on the pulse signals. The preset working conditions include at least an unloaded working condition and a loaded working condition. The speed signal is processed to obtain a corresponding target angle signal, and the target angle signal is subjected to spectrum analysis to obtain the spectrum analysis result of the main shaft torsional vibration. The torsional vibration test result of the main shaft transmission system of the flat sewing machine is determined based on the spectrum analysis result. The aforementioned technical features, by setting test conditions that include at least no-load and loaded conditions, compensate for the lack of unified test standards in existing technologies. This provides a standardized basis for setting test conditions for the torsional vibration test of the sewing machine spindle, resulting in test results with good repeatability and comparability. Simultaneously, by processing the acquired pulse signals to obtain the target angle signal and performing spectral analysis on the target angle signal, a complete and quantifiable evaluation path from the original pulse signal to the angular displacement spectral analysis results is established. This eliminates reliance on manual experience or qualitative judgment, effectively solving the technical problem of accurately verifying and effectively evaluating the spindle torsional vibration performance due to the lack of a standardized evaluation system in existing technologies. Furthermore, by directly using the spectral analysis results to determine the torsional vibration performance test results, the spindle torsional vibration level can be quantitatively characterized. This provides objective data support and judgment basis for the matching rationality of torsional vibration damping mechanisms such as flexible couplings, thus providing a reliable technical means for the development verification and component selection of the spindle transmission system.

[0011] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a flowchart of a torsional vibration testing method provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a torsional vibration testing device provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of a toothed disc structure on a torsional vibration testing device provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of a spindle signal disk pulse signal provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of a rotational speed signal provided in an embodiment of the present invention; Figure 6 This is a color spectrum of torsional vibration signal under steady-state operating conditions of a spindle provided in an embodiment of the present invention; Figure 7 This is a slice spectrum diagram of torsional vibration order during spindle acceleration provided in an embodiment of the present invention; Figure 8 This is a color spectrum of torsional vibration signal during spindle acceleration provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of the structure of a torsional vibration testing device provided in an embodiment of the present invention; Figure 10 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0014] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0015] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0016] Torsional vibration, also known as torsional vibration, refers to the reciprocating vibration in an angular direction generated by elastic deformation and inertia in a rotating shaft system when transmitting power. When the rotating shaft system is subjected to impact or periodic excitation, the system will generate free or forced vibration in the torsional direction. If torsional vibration is not effectively controlled, it can lead to serious problems such as shaft fatigue fracture, damage to connecting parts, operational instability, and abnormal noise. Therefore, the study of torsional vibration in sewing machine transmission shaft systems is of great significance.

[0017] For flatbed sewing machines, torsional vibration in the transmission system mainly originates from changes in the inertial load of the upper and lower shaft transmission components. When torsional damping mechanisms such as flexible couplings are not properly matched, torsional vibration problems easily occur, manifesting at the machine level as low-frequency shaking (during start-up), acceleration booming, and coupling fatigue fracture, among other noise, vibration, and harshness (NVH) issues. Therefore, controlling the torsional vibration of the flatbed sewing machine's main shaft transmission system is a crucial aspect of developing transmission NVH performance. In the early stages of development, optimization can be achieved through computer-aided engineering (CAE) simulations; however, during the prototype calibration phase, torsional vibration analysis and improvements must be based on measured data. Testing the torsional vibration of key nodes in the transmission system serves two purposes: firstly, it allows for the evaluation and acceptance of the transmission NVH subsystem's development goals; secondly, it is an important means of resolving related NVH issues in the transmission system.

[0018] However, the testing, analysis, and evaluation methods for torsional vibration in the sewing machine industry are currently immature, lacking a standardized evaluation system. When faced with requirements such as torsional vibration verification of the development goals of the spindle drive system and related components, and selection and matching of flexible couplings, there are no accurate and reliable testing methods and evaluation standards available.

[0019] Therefore, this invention provides a design scheme for testing and evaluating the torsional vibration of a sewing machine spindle, so as to better control the torsional vibration problem of the spindle transmission system.

[0020] In one embodiment, Figure 1 This is a flowchart of a torsional vibration testing method provided by an embodiment of the present invention. This embodiment can be applied to the torsional vibration performance verification during the development stage of the main shaft transmission system of a flat sewing machine. The method can be executed by a torsional vibration testing device, which can be implemented in hardware and / or software.

[0021] Figure 2 This is a schematic diagram of the structure of a torsional vibration testing device provided in an embodiment of the present invention. Figure 3 This is a schematic diagram of a toothed disc structure on a torsional vibration testing device provided in an embodiment of the present invention. Figure 2 and Figure 3 As shown, the torsional vibration testing equipment mainly consists of a gear disc, gear disc screws, a sensor fixture, and a torsional vibration measuring sensor. The torsional vibration measuring sensor is a magnetoelectric sensor. The gear disc is fixedly mounted on the drive shaft of the sewing machine's main shaft transmission system using gear disc screws. The gear disc has 30 or 60 teeth, evenly distributed 360 degrees circumferentially without any missing teeth. The sensor fixture is located on one side of the gear disc and is used to fix the torsional vibration measuring sensor. After installation, the torsional vibration measuring sensor's central axis points towards the axis of the gear disc and is perpendicular to the tooth surface. The distance between the top of the torsional vibration measuring sensor and the tooth surface of the gear disc is 1mm to 2mm.

[0022] It is understandable that the signal gear and sensor fixture in this embodiment can be modified in terms of material and shape in practical applications, as long as the testing requirements are met, torsional vibration level tests of the spindle drive system can also be performed. In addition to the combination of magnetoelectric sensor and gear, photoelectric sensor and encoder / code tape can also be used to collect spindle torsional vibration signals, meeting the corresponding data acquisition requirements and achieving the same effect.

[0023] like Figure 1 As shown, the method includes: S101. Under preset working conditions, acquire the pulse signal generated when the main shaft transmission system of the flat sewing machine rotates, and generate the main shaft speed signal based on the pulse signal. The preset working conditions include at least no-load working conditions and loaded working conditions.

[0024] In this embodiment, the preset operating conditions can be understood as a set of pre-set spindle operating conditions used to obtain representative and comparable torsional vibration data, including no-load conditions and loaded conditions. The no-load condition refers to the operating state of the flatbed sewing machine when no fabric is being sewn, with the spindle only overcoming its own inertia and frictional resistance. The loaded condition refers to the operating state of the flatbed sewing machine when the spindle needs to overcome the resistance of the sewing material and the resistance of the mechanism's movement during fabric sewing. A flatbed sewing machine is an industrial sewing device that uses the rotation of the spindle to drive the needle-punching mechanism and the fabric feeding mechanism to achieve sewing on flat surfaces. The spindle transmission system can be understood as a power transmission link driven by a motor, transmitting power to the spindle through couplings and other components, and driving the related actuators. A pulse signal can be understood as a sequence of electrical signals generated when a magnetoelectric sensor senses the passage of a signal tooth plate mounted on the spindle; each pulse corresponds to the passing of one tooth. The rotational speed signal can be understood as time-series data reflecting the real-time rotational speed of the spindle, calculated based on the number of pulses collected per unit time.

[0025] Among them, the no-load condition includes different steady-state speed conditions and uniform acceleration conditions from zero to the maximum speed.

[0026] Different steady-state speed operating conditions refer to the process of a flatbed sewing machine operating stably at different speeds when no fabric is being sewn, with a focus on the spindle torsional vibration level at the commonly used speed and the maximum speed. This operating condition is used to obtain the baseline torsional vibration characteristics of the transmission system under no-load conditions, serving as a benchmark for comparison under load conditions, so as to distinguish whether the torsional vibration originates from the inherent characteristics of the system itself or is caused by the load.

[0027] The uniform acceleration condition from zero to maximum speed refers to the process by which a flatbed sewing machine accelerates uniformly from a standstill to its maximum speed when no fabric is being sewn. This condition is used to evaluate the transient changes in torsional vibration energy at each order of the spindle as the speed increases. This condition can identify whether there are sudden changes in torsional vibration within a certain speed range under no-load conditions, providing a reference for judging sudden changes under load conditions and facilitating the separation of the influence of load factors and system-specific factors on sudden changes in torsional vibration.

[0028] Among them, the load-bearing conditions include at least one of the following: steady-state operation condition for sewing fabrics of different thicknesses, uniform acceleration condition, load change condition before and after the needle pierces the fabric, fabric thickness change condition, and reverse sewing operation condition.

[0029] The steady-state operating condition for sewing fabrics of varying thicknesses refers to the operating state of a flatbed sewing machine continuously sewing fabrics of a certain thickness at a constant speed. Fabrics of varying thicknesses include thinner gauze fabrics, standard-thickness denim khaki fabrics, and thicker products such as leather. When sewing standard-thickness fabrics (such as denim khaki), this operating condition is used to evaluate the magnitude of the first four orders of torsional vibration of the spindle during steady-state operation at both the commonly used and maximum speeds, as well as the transient changes in torsional vibration energy at each order of the spindle under uniform acceleration from zero to the maximum speed, and whether there are any significant abrupt changes. When sewing fabrics of different thicknesses separately, this operating condition is also used to evaluate the magnitude and energy changes of the first four orders of torsional vibration of the spindle during steady-state operation at both the commonly used and maximum speeds, assess the differences in the first four orders of torsional vibration energy of the spindle drive system under different load conditions and the load-bearing range, and the transient changes in torsional vibration energy at each order of the spindle under uniform acceleration from zero to the maximum speed, and whether there are any significant abrupt changes.

[0030] Uniform acceleration mode refers to the process of a flatbed sewing machine accelerating uniformly from zero to its maximum speed, simulating the actual acceleration process of a sewing machine from the start of sewing to stable operation. This mode is used to evaluate the transient changes in the torsional vibration energy of the spindle at each order as the speed increases, and to determine whether there are obvious abrupt changes within a certain speed range.

[0031] The load change condition before and after the needle pierces the fabric refers to the sudden change in load that occurs during the sewing of thicker fabrics (such as leather goods, thick woolen fabrics, and thick cotton and linen fabrics) at both the normal and maximum speeds, from the moment the needle pierces the fabric from top to bottom and after piercing. This condition is analyzed by examining the energy differences and magnitudes of the various orders of torsional vibration of the spindle before and after the needle pierces the fabric, to determine whether the stiffness and other characteristics of the spindle transmission system are matched.

[0032] The fabric thickness abrupt change condition refers to the operating state when the fabric thickness changes suddenly during sewing, often referred to as the "over-stitch" condition. This condition is used to evaluate the dynamic changes in the first four orders of torsional vibration energy of the spindle before and after the thickness abrupt change during normal and maximum speed operation, in order to assess the range of instantaneous torsional vibration energy that the spindle drive system can withstand.

[0033] The reverse sewing operation condition refers to the operating state of a sewing machine when performing reverse sewing operations, that is, the fabric is fed in the reverse direction during the sewing process. This condition is used to evaluate the magnitude and energy variation of the first four torsional vibration levels of the main shaft drive system during reverse sewing operations of a sewing machine under different load conditions.

[0034] Specifically, after the flatbed sewing machine is started and runs stably for a period of time (e.g., two minutes), a torsional vibration test is performed. During the test, a magnetoelectric sensor located at the position of the drive shaft at the output end of the main spindle motor collects the pulse signal from the main spindle signal disk at the output end. Figure 4 This is a schematic diagram of a spindle signal disk pulse signal provided in an embodiment of the present invention, as shown below. Figure 4As shown, the sampling bandwidth is set to 12kHz, and the frequency resolution is 1Hz. The preset working conditions collected include no-load and loaded states, where the no-load state is the flatbed sewing machine in no-load state, and the loaded state is the flatbed sewing machine in loaded (sewing fabric) state. For each working condition, when the spindle rotates, the magnetoelectric sensor continuously collects the pulse signal generated when the tooth surface of the signal tooth plate passes by. The frequency of this pulse signal is proportional to the spindle speed. The high-precision spindle speed signal that varies with time is generated by the pulse signal of the spindle signal plate at the output end of the spindle motor, thereby obtaining the spindle speed data.

[0035] S102. Perform signal processing on the rotation speed signal to obtain the corresponding target angle signal, and perform spectrum analysis on the target angle signal to obtain the spectrum analysis results of the spindle torsional vibration.

[0036] In this embodiment, the target angle signal is an angle-type signal characterizing the torsional vibration level of the spindle, and its form includes angular displacement, angular velocity, or angular acceleration. Specifically, angular displacement is a data sequence characterizing the change of the spindle's angular displacement relative to a reference position in the rotational direction over time, with the unit being degrees (deg); angular velocity is a physical quantity characterizing the rate of change of the spindle's angular displacement over time, with the unit being degrees per second (deg / s); and angular acceleration is a physical quantity characterizing the rate of change of the spindle's angular velocity over time, with the unit being degrees per second. 2 (deg / s) 2 This embodiment uses angular displacement as an example, that is, angular displacement is used as the target angular signal to characterize the spindle torsional vibration level. The spectrum analysis results can be understood as frequency domain data that reflects the amplitude distribution information of spindle torsional vibration at various frequencies and orders after spectrum transformation, and can be presented in the form of color maps or other color spectra.

[0037] Specifically, the high-precision spindle speed signal is first subjected to a high-pass 8Hz filter to eliminate low-frequency noise such as environmental signals and improve the signal-to-noise ratio. The high-pass filtered speed signal is then processed by order slicing, typically extracting first, second, and third-order slices of spindle angular velocity fluctuations, converted to deg / s. Next, the torsional vibration signal after order slicing is integrated, with the unit chosen as deg, i.e., angular displacement. Finally, the spindle torsional vibration signal is subjected to spectral analysis to obtain a colormap of the steady-state spindle torsional vibration signal. The spectral analysis results are then derived based on this colormap and the order slice spectrum. These spectral analysis results reflect the torsional vibration energy distribution at different frequencies and orders, providing a quantitative frequency domain data basis for subsequent performance evaluation.

[0038] S103. Determine the torsional vibration test results of the main shaft transmission system of the flat sewing machine based on the spectrum analysis results.

[0039] In this embodiment, the torsional vibration test result can be understood as a conclusion reflecting whether the torsional vibration performance of the spindle drive system meets the design requirements, obtained after analyzing the spectrum analysis results according to preset evaluation criteria. The torsional vibration analysis results include frequency (vertical axis, unit: Hertz), rotational speed or time (horizontal axis, rotational speed unit: revolutions per minute, time unit: seconds), and amplitude of the torsional vibration angle signal (represented by color depth, unit: degrees). These together constitute the complete distribution information of the torsional vibration signal in the frequency domain and time / rotational speed domain. From the torsional vibration analysis results, the amplitude of the angle signal of each order of torsional vibration can be extracted to determine whether each order of torsional vibration meets the limiting requirements; the rotational speed range and frequency range where the torsional vibration energy is concentrated can be identified to locate the order of exceeding the standard and its corresponding rotational speed range; and the difference in torsional vibration energy between no-load and loaded conditions at the same rotational speed can be extracted to locate problematic components.

[0040] Specifically, the amplitudes of the torsional vibration angle signals of each order extracted from the spectrum analysis results are compared one by one with the preset torsional vibration thresholds. Taking the target angle signal as angular displacement as an example, the corresponding angle signal amplitude is the angular displacement amplitude in degrees (deg). The corresponding preset torsional vibration thresholds are: 0.15 degrees for torsional vibration under no-load conditions and 0.15 degrees for torsional vibration under load conditions. If the angular displacement amplitude of each order of torsional vibration does not exceed 0.15 degrees, the torsional vibration test result is determined to meet the requirements of the spindle torsional vibration performance, and the spindle transmission system can be considered qualified for torsional vibration, thus ending the test for this working condition. If the angular displacement amplitude of any order of torsional vibration exceeds 0.15 degrees, the torsional vibration test result is determined to not meet the requirements of the spindle torsional vibration performance. Then, by combining torsional vibration order energy analysis and other methods, the components with excessive torsional vibration are located, an optimization plan is formulated, and then the next round of testing and verification begins after the optimization plan is implemented.

[0041] It is understandable that different preset torsional vibration thresholds are used for comparison for different target angle signal types.

[0042] It is understood that in this embodiment, the preset torsional vibration threshold (torsional vibration limit) for both the no-load condition (no-load state of the flat sewing machine) and the loaded condition (loaded state of the flat sewing machine) is set to 0.15deg. However, this value is only an example. In fact, the preset torsional vibration threshold for the no-load condition and the loaded condition can be other values ​​or different values. Even, the preset torsional vibration threshold for different conditions in the loaded condition can be the same or different values ​​that are predefined.

[0043] This invention provides a torsional vibration testing method, comprising: acquiring pulse signals generated when the main shaft drive system of a sewing machine rotates under preset working conditions; generating a main shaft speed signal based on the pulse signals; the preset working conditions at least including an unloaded working condition and a loaded working condition; processing the speed signal to obtain a corresponding target angle signal; performing spectral analysis on the target angle signal to obtain a spectral analysis result of the main shaft torsional vibration; and determining the torsional vibration test result of the main shaft drive system of the sewing machine based on the spectral analysis result. The above technical solution involves acquiring pulse signals generated when the main shaft drive system of a sewing machine rotates under preset working conditions, generating a main shaft speed signal based on the pulse signals, the preset working conditions at least including an unloaded working condition and a loaded working condition; processing the speed signal to obtain a corresponding target angle signal; performing spectral analysis on the target angle signal to obtain a spectral analysis result of the main shaft torsional vibration; and determining the torsional vibration test result of the main shaft drive system of the sewing machine based on the spectral analysis result. The aforementioned technical features, by setting test conditions that include at least no-load and loaded conditions, compensate for the lack of unified test standards in existing technologies. This provides a standardized basis for setting test conditions for the torsional vibration test of the sewing machine spindle, resulting in test results with good repeatability and comparability. Simultaneously, by processing the acquired pulse signals to obtain the target angle signal and performing spectral analysis on the target angle signal, a complete and quantifiable evaluation path from the original pulse signal to the angular displacement spectral analysis results is established. This eliminates reliance on manual experience or qualitative judgment, effectively solving the technical problem of accurately verifying and effectively evaluating the spindle torsional vibration performance due to the lack of a standardized evaluation system in existing technologies. Furthermore, by directly using the spectral analysis results to determine the torsional vibration performance test results, the spindle torsional vibration level can be quantitatively characterized. This provides objective data support and judgment basis for the matching rationality of torsional vibration damping mechanisms such as flexible couplings, thus providing a reliable technical means for the development verification and component selection of the spindle transmission system.

[0044] As a first optional embodiment of this example, the rotational speed signal is processed to obtain the corresponding target angle signal, and the target angle signal is subjected to spectral analysis to obtain the spectral analysis results of the spindle torsional vibration, including: a1. Perform high-pass filtering on the speed signal.

[0045] Figure 5 This is a schematic diagram of a rotational speed signal provided in an embodiment of the present invention, as shown below. Figure 5 As shown, in torsional vibration testing, the spindle speed signal contains low-frequency noise components introduced by non-torsional vibration factors such as environmental vibration and equipment foundation vibration. High-pass filtering can effectively remove these irrelevant low-frequency interferences. Therefore, the generated high-precision spindle speed signal is subjected to Highpass 8Hz high-pass filtering. Here, the cutoff frequency is set to 8Hz, allowing frequency components above 8Hz to pass while attenuating low-frequency signal components below 8Hz.

[0046] High-pass filtering of the rotation speed signal can eliminate low-frequency noise introduced by environmental vibration, sensor temperature drift, and equipment foundation vibration, thereby improving the purity and signal-to-noise ratio of the torsional vibration signal and ensuring that the data used in subsequent analysis accurately reflects the true torsional vibration characteristics of the spindle.

[0047] b1. Perform order slicing on the filtered rotational speed signal to extract at least one order component of the spindle angular velocity fluctuation and obtain the corresponding torsional vibration signal.

[0048] In this embodiment, the order components can be understood as vibrational components in the signal whose frequencies are integer multiples of the spindle's fundamental rotation frequency. The first-order component corresponds to one vibration per revolution of the spindle, the second-order component corresponds to two vibrations per revolution, and so on. The torsional vibration signal can be understood as a data sequence reflecting the angular velocity fluctuations or angular displacement changes of the spindle in the rotational direction, extracted after order slicing. Here, it specifically refers to the angular velocity fluctuation components corresponding to each order.

[0049] Specifically, the high-pass filtered rotational speed signal is processed by order slicing, typically extracting first, second, and third order slices of spindle angular velocity fluctuation, and converting the units to deg / s.

[0050] The purpose of order slicing is to separate the torsional vibration components of different orders in the rotational speed signal. Since different orders of torsional vibration in the main shaft drive system of a flat sewing machine often correspond to different excitation sources (such as main shaft imbalance, coupling elastic deformation, and periodic loads on the mechanism), order slicing can separate these mixed torsional vibration components by order, allowing for subsequent quantitative analysis of each order. The number of orders extracted is unlimited; the range of orders can be selected according to actual testing needs. This embodiment does not impose any limitations on this.

[0051] c1. Integrate the torsional vibration signals of each order to convert them into the corresponding target angle signals.

[0052] Specifically, taking angular displacement as the target angle signal as an example, the torsional vibration signal after order slicing is integrated, with the unit chosen as deg, i.e., angular displacement. The torsional vibration signal representing angular velocity fluctuations obtained after order slicing is converted into a target angle signal through integration. The torsional vibration signal of each order is integrated independently to obtain the target angle signal corresponding to each order, thereby converting the torsional vibration information in the velocity domain into torsional vibration information in the displacement domain.

[0053] d1. Perform spectral analysis on the target angle signals of each order to obtain the spectral analysis results of torsional vibration of each order.

[0054] Specifically, spectral analysis is performed on the target angle signals of each order, and the time-domain variation data of the angle signals of each order are converted into frequency-domain representations to obtain the spectral analysis results of torsional vibration of each order, which can show the variation of the amplitude of torsional vibration of each order with rotational speed or frequency. Figure 6 This is a color spectrum of torsional vibration signal under steady-state operating conditions of a spindle provided in an embodiment of the present invention, generally referring to the torsional vibration spectrum analysis results under all constant speeds, such as... Figure 6 As shown, the target angle signal uses angular displacement signal, with the vertical axis f / Hz representing frequency and the horizontal axis t / s representing time. The upper curve in the figure reflects the change of spindle speed over time, and the grayscale or color depth of the lower colormap represents the magnitude of torsional angular displacement, used to visually demonstrate the distribution characteristics of spindle torsional energy with frequency and time. The darker the color (or the warmer the color), the larger the torsional angular displacement amplitude at that frequency, and vice versa.

[0055] Furthermore, at least one order component of the principal spindle angular velocity fluctuation is extracted, including: Extract the first four orders of the spindle angular velocity fluctuation.

[0056] The first four order components refer to the 1st, 2nd, 3rd, and 4th order components. In the order slicing process, each order component is extracted independently and used as the corresponding torsional vibration signal in subsequent analysis. Each rotation of the sewing machine spindle completes a full sewing cycle, and the changes in inertial loads of its transmission system components manifest as torsional vibration components of different orders in the order domain.

[0057] Specifically, when performing order slicing on the filtered rotational speed signal, the 1st, 2nd, 3rd, and 4th order components of the spindle angular velocity fluctuation are extracted. These extractions yield the corresponding torsional vibration signals for each of the four orders, providing a data foundation for subsequent integration and spectral analysis of each order.

[0058] As a second optional embodiment of this example, determining the torsional vibration test results of the main shaft drive system of the flat sewing machine based on the spectrum analysis results includes: a2. Compare the angular signal amplitude in the spectral analysis results of each order of torsional vibration with the preset torsional vibration threshold.

[0059] In this embodiment, the angular signal amplitude can be understood as the peak value of the target angular signal of each order of torsional vibration extracted from the spectrum analysis results, used to quantify the severity of each order of torsional vibration. When the target angular signal is angular displacement, the angular signal amplitude is the angular displacement amplitude; when the target angular signal is angular velocity, the angular signal amplitude is the angular velocity amplitude; when the target angular signal is angular acceleration, the angular signal amplitude is the angular acceleration amplitude. The preset torsional vibration threshold can be understood as a pre-set upper limit for the angular signal amplitude, serving as a benchmark value for judging whether the torsional vibration performance is qualified. For example, the torsional vibration limit for angular displacement is 0.15 degrees for both the no-load state and the loaded state of the flatbed sewing machine.

[0060] Specifically, for the torsional vibration spectrum analysis results of each order, the angular signal amplitude corresponding to each order is extracted, and the angular signal amplitude of each order is compared with the preset torsional vibration threshold to determine whether the torsional vibration level of each order is within the allowable range.

[0061] b2. If the amplitude of the angular signal of each order of torsional vibration is less than or equal to the preset torsional vibration threshold, then the torsional vibration test result is determined to meet the requirements of the spindle torsional vibration performance.

[0062] Meeting the requirements for spindle torsional vibration performance means that the torsional vibration level of the spindle drive system at each order does not exceed the allowable upper limit, indicating that the current system's torsional vibration performance is acceptable and no structural or parameter adjustments are required.

[0063] Specifically, if the amplitude of the angular signal at all orders does not exceed the preset torsional vibration threshold, the spindle torsional vibration test result is deemed qualified, meaning the spindle torsional vibration performance meets the requirements.

[0064] c2. If the amplitude of the angular signal of any order of torsional vibration is greater than the preset torsional vibration threshold, then the torsional vibration test result is determined to be that the spindle torsional vibration performance does not meet the requirements.

[0065] The spindle torsional vibration performance does not meet the requirements, which means that there is at least one order of torsional vibration level in the spindle drive system that exceeds the upper limit of the allowable limit. This indicates that the current system is not up to standard in terms of torsional vibration and the relevant components need to be optimized and adjusted.

[0066] Specifically, if the amplitude of any angular signal exceeds the preset torsional vibration threshold, the spindle torsional vibration test result is deemed unqualified, meaning the spindle torsional vibration performance does not meet the requirements.

[0067] As a third optional embodiment of this example, the method further includes: a3. Extract the difference in torsional vibration energy between no-load and loaded conditions at the same rotational speed.

[0068] In this embodiment, torsional vibration energy can be understood as the vibration energy contained in the spindle during torsional vibration, used to characterize the severity of torsional vibration. The difference in torsional vibration energy refers to the difference between the torsional vibration energy under load and unloaded conditions at the same rotational speed, reflecting the degree of influence of load application on the torsional vibration characteristics of the spindle transmission system.

[0069] Specifically, from the spectral analysis results of no-load and loaded conditions, the torsional vibration energy values ​​of the two conditions at the same speed are extracted, and the difference between the two is calculated. By using the difference in torsional vibration energy between no-load and loaded conditions, the energy increment of the loaded condition compared to the no-load condition is evaluated, thereby determining the degree of excitation of torsional vibration by the load and quantifying the contribution of the load to the torsional vibration energy. Based on this, the torsional vibration level exceeding the standard under loaded conditions and the energy difference compared to the no-load condition are evaluated, which helps to locate the corresponding problematic components under that speed and load condition, providing a basis for subsequent optimization.

[0070] b3. When the torsional vibration test results show that the spindle's torsional vibration performance does not meet the requirements, the problematic components of the sewing machine's spindle transmission system are determined based on the difference in torsional vibration energy.

[0071] In this embodiment, the problematic component can be understood as a part in the spindle drive system that causes the torsional vibration performance to fail to meet the requirements and generates abnormal torsional vibration energy under specific working conditions, such as the flexible coupling, the spindle itself, or other mechanical components in the drive chain.

[0072] Specifically, when the spindle's torsional vibration performance is determined to be unsatisfactory, the difference in torsional vibration energy between no-load and loaded conditions is analyzed. By examining the correlation between the energy difference and the order of the out-of-range vibration, the source of the problem can be identified as one or more components, allowing for targeted optimization. For example, if the torsional vibration is normal under no-load conditions but exceeds the standard after loading a specific thickness of fabric, it indicates that the problem stems from an excessive excitation response of a certain component under load. Combining this with the characteristic frequency of the out-of-range order can further pinpoint the specific rotating component, leading to the generation of an optimization scheme.

[0073] For example, the torsional vibration level of the spindle drive system of a flatbed sewing machine (model A) is checked. The test condition is: sewing thicker fabrics such as wool, with uniform acceleration from zero to the maximum speed, simulating the process of the sewing machine from the start of sewing to stable operation. The test is conducted according to the torsional vibration test and evaluation method of the flatbed sewing machine spindle provided in this embodiment to obtain the torsional vibration level of the flatbed sewing machine spindle.

[0074] Figure 7 This is a slice spectrum diagram of torsional vibration order during spindle acceleration provided in an embodiment of the present invention. Figure 7As shown, the horizontal axis represents the spindle speed in revolutions per minute (rpm), and the vertical axis represents the torsional vibration amplitude in degrees (°). Pulse 2.00 Order = 0.15° indicates that the second-order torsional vibration amplitude is approximately 0.15°, and Pulse 4.00 Order = 0.021° indicates that the fourth-order torsional vibration amplitude is approximately 0.021°. Combined with the 0.15° limit, it can be seen that the second-order torsional vibration reaches approximately 0.15° below 2700 rpm, exceeding the limit; while the fourth-order torsional vibration is less than 0.15° throughout the entire acceleration process, with an amplitude of only approximately 0.021°, meeting the limit.

[0075] Figure 8 This is a color spectrum of torsional vibration signals during the spindle acceleration process provided in an embodiment of the present invention. For example... Figure 8 As shown, the horizontal axis represents the spindle speed in revolutions per minute (rpm), and the vertical axis represents the frequency in Hertz (Hz). The darker the color, the greater the torsional amplitude at the corresponding frequency at that speed. Figure 8 In the low-speed range (approximately 1500-2500 rpm) and near the corresponding second-order frequency (frequency = order × speed ÷ 60, second-order corresponds to approximately 50-83 Hz), a dark area appears, indicating a concentration of second-order torsional vibration energy within this speed range; while the fourth-order frequency (approximately 100-167 Hz) remains relatively light in color, which is related to... Figure 7 The conclusion that the fourth-order torsional vibration meets the limiting requirements is consistent.

[0076] Torsional vibration analysis results show that under accelerated sewing conditions of thick fabrics, the fourth-order torsional vibration level of the main shaft of the flatbed sewing machine meets the requirement of less than 0.15 degrees, while the second-order torsional vibration level exceeds the 0.15-degree limit below 2700 rpm. Therefore, it is determined that the fourth-order torsional vibration level of the main shaft of the A flatbed sewing machine meets the requirements under accelerated sewing conditions of thick fabrics, but the second-order torsional vibration of the main shaft needs to be closely monitored, especially under low-speed load conditions below 2700 rpm. To address this issue, the main shaft material with higher stiffness can be replaced, or a coupling with better damping characteristics can be selected, followed by torsional vibration verification.

[0077] This invention proposes for the first time a complete method for testing and evaluating the torsional vibration of the spindle drive system of a flatbed sewing machine. From the selection of test conditions to the evaluation of torsional vibration levels, the logic is simple and clear, the analysis is efficient and quick, and it is universal. By changing the sensor fixing fixture, it can be applied to most sewing machine models. This invention combines the complex and varied actual usage scenarios of sewing machines and for the first time incorporates the working characteristics and unique sewing cycle of the sewing machine itself into the testing and evaluation system of spindle torsional vibration. The selection of test conditions includes two main categories: no-load and loaded. Under the loaded condition, it further covers a variety of actual sewing scenarios such as steady-state operation of sewing fabrics of different thicknesses, uniform acceleration, sudden load changes before and after the needle penetrates the fabric, sudden changes in fabric thickness (overstitching), and reverse sewing operation. This makes the test conditions closely resemble the unique working attributes of the flatbed sewing machine, and the evaluation results more comprehensively and objectively reflect the torsional vibration level of the spindle drive system under real usage conditions. By analyzing the difference in peak torsional vibration energy of the main shaft before and after the needle pierces the fabric, as well as the energy changes at each order, it is possible to effectively determine whether the stiffness and damping characteristics of the transmission system are matched. Compared with existing technologies that only make qualitative judgments of whether the performance is qualified or not, this invention achieves a deep quantitative evaluation of the torsional vibration performance of the main shaft transmission system and can quickly identify problematic components, providing clear data support and optimization directions for the selection of main shaft materials and couplings. In addition, this invention effectively solves the technical problem of the lack of unified testing standards and standardized evaluation systems in the flatbed sewing machine industry by using a low-cost torsional vibration testing device and an efficient torsional vibration testing and analysis method, filling the technical gap in the torsional vibration testing and analysis of the main shaft transmission system of flatbed sewing machines.

[0078] In one embodiment, Figure 9 This is a schematic diagram of the structure of a torsional vibration testing device provided in an embodiment of the present invention. Figure 9 As shown, the device includes: The signal acquisition module 21 is used to acquire the pulse signal generated when the main shaft transmission system of the flat sewing machine rotates under preset working conditions, and generate the main shaft speed signal according to the pulse signal. The preset working conditions include at least no-load working conditions and loaded working conditions. The spectrum analysis module 22 is used to process the rotation speed signal to obtain the corresponding target angle signal, and to perform spectrum analysis on the target angle signal to obtain the spectrum analysis result of the spindle torsional vibration. Torsional vibration test module 23 is used to determine the torsional vibration test results of the main shaft transmission system of the flat sewing machine based on the spectrum analysis results.

[0079] The torsional vibration testing device used in this technical solution solves the problem that existing flat sewing machine spindle torsional vibration testing lacks a unified standard and standardized evaluation system, making accurate verification and evaluation impossible.

[0080] Optionally, the load-bearing conditions include at least one of the following: steady-state operation condition for sewing fabrics of different thicknesses, uniform acceleration condition, load change condition before and after the needle pierces the fabric, fabric thickness change condition, and reverse sewing operation condition.

[0081] Optionally, the spectrum analysis module 22 includes: The filtering unit is used to perform high-pass filtering on the rotation speed signal; The slicing unit is used to perform order slicing processing on the filtered rotational speed signal, extract at least one order component of the spindle angular velocity fluctuation, and obtain the corresponding torsional vibration signal. The integrator unit is used to integrate the torsional vibration signals of each order and convert them into the corresponding target angle signals. The spectrum analysis unit is used to perform spectrum analysis on the target angle signal of each order to obtain the spectrum analysis results of the torsional vibration of each order.

[0082] Optionally, the slicing unit is specifically used for: Extract the first four orders of the spindle angular velocity fluctuation.

[0083] Optionally, the torsional vibration testing module 23 is specifically used for: The amplitude of the angular signal in the spectral analysis results of each order of torsional vibration is compared with the preset torsional vibration threshold. If the amplitude of the angular signal of each order of torsional vibration is less than or equal to the preset torsional vibration threshold, then the torsional vibration test result is determined to meet the requirements of the spindle torsional vibration performance. If the amplitude of the angular signal of any order of torsional vibration is greater than the preset torsional vibration threshold, then the torsional vibration test result is determined to be that the spindle torsional vibration performance does not meet the requirements.

[0084] Optionally, the device further includes a problematic component positioning unit, specifically used for: Extract the difference in torsional vibration energy between no-load and loaded conditions at the same rotational speed; When the torsional vibration test results show that the spindle torsional vibration performance does not meet the requirements, the problematic components of the sewing machine spindle transmission system are identified based on the difference in torsional vibration energy.

[0085] The torsional vibration testing device provided in the embodiments of the present invention can execute the torsional vibration testing method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the method.

[0086] In one embodiment, Figure 10 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. For example... Figure 10The diagram illustrates a schematic representation of an electronic device 10 that can be used to implement embodiments of the present invention. The electronic device 10 is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device 10 may also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (e.g., helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0087] like Figure 10 As shown, the electronic device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12 or a random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the ROM 12 or loaded from storage unit 18 into the RAM 13. The RAM 13 can also store various programs and data required for the operation of the electronic device 10. The processor 11, ROM 12, and RAM 13 are interconnected via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0088] Multiple components in electronic device 10 are connected to I / O interface 15, including: input unit 16, such as keyboard, mouse, etc.; output unit 17, such as various types of displays, speakers, etc.; storage unit 18, such as disk, optical disk, etc.; and communication unit 19, such as network card, modem, wireless transceiver, etc. Communication unit 19 allows electronic device 10 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0089] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, central processing units, graphics processing units, various special-purpose artificial intelligence computing chips, various processors running machine learning model algorithms, digital signal processors, and any suitable processor, controller, microcontroller, etc. Processor 11 performs the various methods and processes described above, such as torsional vibration testing methods.

[0090] In some embodiments, the torsional vibration testing method may be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program may be loaded and / or installed on electronic device 10 via ROM 12 and / or communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the torsional vibration testing method described above may be performed. Alternatively, in other embodiments, processor 11 may be configured to perform the torsional vibration testing method by any other suitable means (e.g., by means of firmware).

[0091] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays, application-specific integrated circuits (ASICs), application-specific standard products (ASICs), systems-on-a-chip (SoCs), payload programmable logic devices, computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0092] Computer programs used to implement the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0093] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory, read-only memory, erasable programmable read-only memory, optical fibers, portable compact disk read-only memory, optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0094] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a cathode ray tube or liquid crystal display) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0095] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or computing systems that include middleware components (e.g., application servers), or computing systems that include frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0096] A computing system can include clients and servers. Clients and servers are generally geographically separated and typically interact via communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a host product within the cloud computing service system to address the shortcomings of traditional physical host and virtual machine services, such as high management difficulty and weak business scalability.

[0097] This invention also provides a computer program product, including a computer program that, when executed by a processor, can implement the torsional vibration testing method provided in any embodiment of this invention.

[0098] In implementing the computer program product, computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof. Programming languages ​​include object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including local area networks (LANs) or wide area networks (WANs), or it can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0099] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0100] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A torsional vibration testing method, characterized in that, include: Under preset working conditions, the pulse signal generated when the main shaft transmission system of the flat sewing machine rotates is collected, and the main shaft speed signal is generated based on the pulse signal. The preset working conditions include at least no-load working conditions and loaded working conditions. The rotational speed signal is processed to obtain the corresponding target angle signal, and the target angle signal is subjected to spectrum analysis to obtain the spectrum analysis results of the spindle torsional vibration. The torsional vibration test results of the main shaft drive system of the flat sewing machine were determined based on the spectrum analysis results.

2. The method according to claim 1, characterized in that, The load conditions include at least one of the following: steady-state operation condition for sewing fabrics of different thicknesses, uniform acceleration condition, load change condition before and after the needle pierces the fabric, fabric thickness change condition, and reverse sewing operation condition.

3. The method according to claim 1, characterized in that, The process of processing the rotational speed signal to obtain the corresponding target angle signal, and performing spectral analysis on the target angle signal to obtain the spectral analysis results of the spindle torsional vibration, includes: The rotational speed signal is subjected to high-pass filtering. The filtered rotational speed signal is processed by order slicing to extract at least one order component of the spindle angular velocity fluctuation, and the corresponding torsional vibration signal is obtained. The torsional vibration signals of each order are integrated and converted into the corresponding target angle signals. Spectral analysis was performed on the target angle signals of each order to obtain the spectral analysis results of torsional vibration of each order.

4. The method according to claim 3, characterized in that, The extraction of at least one order component of the spindle angular velocity fluctuation includes: Extract the first four orders of the spindle angular velocity fluctuation.

5. The method according to claim 1, characterized in that, The determination of the torsional vibration test results of the main shaft drive system of the flat sewing machine based on the spectrum analysis results includes: The amplitude of the angular signal in the spectral analysis results of each order of torsional vibration is compared with the preset torsional vibration threshold. If the amplitude of the angular signal of each order of torsional vibration is less than or equal to the preset torsional vibration threshold, then the torsional vibration test result is determined to meet the requirements of the spindle torsional vibration performance. If the amplitude of the angular signal of any order of torsional vibration is greater than the preset torsional vibration threshold, then the torsional vibration test result is determined to be that the spindle torsional vibration performance does not meet the requirements.

6. The method according to claim 1, characterized in that, Also includes: Extract the difference in torsional vibration energy between no-load and loaded conditions at the same rotational speed; When the torsional vibration test results show that the spindle's torsional vibration performance does not meet the requirements, the problematic components of the sewing machine's spindle transmission system are identified based on the difference in torsional vibration energy.

7. A torsional vibration testing device, characterized in that, include: The signal acquisition module is used to acquire the pulse signal generated when the main shaft transmission system of the flat sewing machine rotates under preset working conditions, and generate the main shaft speed signal based on the pulse signal. The preset working conditions include at least no-load working conditions and loaded working conditions. The spectrum analysis module is used to process the rotational speed signal to obtain the corresponding target angle signal, and to perform spectrum analysis on the target angle signal to obtain the spectrum analysis results of the spindle torsional vibration. The torsional vibration test module is used to determine the torsional vibration test results of the main shaft transmission system of the flat sewing machine based on the spectrum analysis results.

8. An electronic device, characterized in that, include: At least one processor; as well as A memory communicatively connected to the at least one processor; wherein, The memory stores a computer program that can be executed by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform a torsional vibration testing method according to any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that, when executed by a processor, implement a torsional vibration testing method according to any one of claims 1-6.

10. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, implements a torsional vibration testing method according to any one of claims 1-6.

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