Air jet loom rack vibration transmission path analysis method and system

Abstract

The invention provides an air jet loom rack vibration transmission path analysis method and system. The method comprises the following steps: acquiring acceleration signals of a target reference point, a vibration source path input connection part and a vibration source under a working condition; removing an active end excitation source, hammering passive end positions of excitation positions of left and right wallboards, carrying out system frequency response function testing, and carrying out filtering processing on vibration data of response points to obtain a system frequency response function; defining a transmission path of vibration from the excitation source to the target response point through the connecting piece, and establishing a vibration transmission path analysis model of the air jet loom; the identification model carries out operation condition load calculation; multiplying a passive end load by a corresponding path frequency response function to obtain a path contribution amount of each target point; according to the method, filtering processing is introduced and correction parameters are inserted under the condition of ultra-high-speed operation, so that the precision and the accuracy of vibration transmission path analysis are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of vibration analysis of textile machinery, and particularly to a method and system for analyzing the vibration transmission path of a projectile loom frame. Background Art

[0002] A projectile loom is an important device in modern textile industry, featuring high speed and high efficiency. With the increasing demand for textiles and the improvement of production efficiency requirements, the speed of projectile looms has been continuously increased to reach a super-high-speed operation state. However, the vibration problems brought about by high-speed operation have become the key factors restricting the performance and lifespan of the loom. Especially in the frame structure, vibration can cause structural fatigue, increased noise, and decreased fabric quality. Therefore, by accurately identifying the vibration-sensitive paths, it provides a basis for vibration reduction optimization.

[0003] A method for identifying the noise of high-end textile machinery based on transfer path analysis with the publication number CN108593092A includes the following steps: measuring the frequency response function of the transfer paths of multiple excitation sources; measuring the sound pressure and working load under the working conditions; calculating the noise contribution amount through the acceleration of the excitation source, the sound pressure under the working conditions, and the working load.

[0004] However, currently in a projectile loom running at high speed, the vibrations of vibration sources such as motors and cams are transmitted to the frame structure through different paths, thereby affecting the overall performance of the loom. Traditional vibration analysis methods are difficult to accurately capture complex vibration transmission paths. Especially under super-high-speed conditions, the vibration signals are complex and easily affected by noise, and the yarn tension during the operation of moving components will also affect the experimental data, thus reducing the accuracy and precision of the vibration transmission path analysis. Summary of the Invention

[0005] In view of this, the present invention proposes a method and system for analyzing the vibration transmission path of a projectile loom frame, which can filter out interference noise under super-high-speed operation conditions, accurately capture complex vibration transmission paths, and insert correction parameters to correct the influence of yarn tension, thereby improving the accuracy and precision of the vibration transmission path analysis.

[0006] The technical solution of the present invention is realized as follows: In the first aspect, the present invention provides a method for analyzing the vibration transmission path of a projectile loom frame, including the following steps: S1, obtaining the acceleration signals of the target reference point, the input connection points of the vibration source paths, and the vibration sources under the working conditions; S2, removing the active-end excitation source, hammering the passive-end positions at the excitation points of the left and right wallboards, conducting a system frequency response function test, and filtering the vibration data of the response points to obtain the system frequency response function; S3. Using the main motor, cam box, small pulley and large pulley as excitation sources, the suspension elements as connecting components, and the passive end of the wallboard as the target response point, define the vibration transmission path from the excitation source through the connecting component to the target response point, and establish an analysis model for the vibration transmission path of the air-jet loom. S4. Introduce the yarn tension and air damping correction parameters to correct the dynamic stiffness model of the suspension element, and calculate the structural vibration load force transmitted from the suspension element to the passive end based on the corrected dynamic stiffness model. S5. Multiply the structural vibration load force at the passive end by the frequency response function of the corresponding path, calculate the contribution of each path, compare the contribution sizes of each path, and take the path with the largest contribution as the vibration-sensitive path.

[0007] Based on the above technical solutions, preferably, in step S1, obtain the acceleration signals of the target reference point, the connection point of the vibration source path input, and the vibration source under the working conditions. Among them, acceleration sensors are respectively arranged at the motor, cam box, beating-up mechanism, shedding mechanism, let-off mechanism, main shaft vibration source, and the passive ends of the left wallboard and right wallboard, and the loom response point. Under the operating state of the air-jet loom, collect the vibration signals at different speeds, obtain the vibration amplitude frequencies in the X, Y, and Z directions, and calculate the root mean square value of the vibration acceleration for evaluating the vibration state of the loom.

[0008] Based on the above technical solutions, preferably, in step S2, remove the active end excitation source, hammer the passive end positions of the left and right wallboards at the excitation points, conduct a system frequency response function test, collect the vibration response data of each response point, and filter the vibration response data to obtain the system frequency response function, which includes the following sub-steps: S21. Divide the moving components of the air-jet loom into the shedding mechanism, beating-up mechanism, and let-off mechanism, and set the corresponding attenuation coefficients according to their positions corresponding to the loom frame. S22. Control the movement of a single mechanism by regulating the loom system, install acceleration sensors at the measurement points of each mechanism, hammer the passive end positions of the left and right wallboards at the excitation points, collect the vibration response data of the air-jet loom under various working conditions, and filter the vibration response data using a low-pass filter to establish the corresponding system frequency response function.

[0009] Based on the above technical solutions, preferably, the expression of the system frequency response function is:

[0010] In the formula, f ( t ) is the system frequency response function corresponding to the air-jet loom at t moment, a is the attenuation coefficient of the shedding mechanism from the loom frame, U (t ) is the frequency response data matrix of the shedding mechanism, b is the attenuation coefficient of the beat-up mechanism from the frame, L ( t ) is the frequency response data matrix of the beat-up mechanism, c is the attenuation coefficient of the let-off mechanism from the frame, P ( t ) is the frequency response data matrix of the let-off mechanism; Among them,

[0011] Among them: ; ; ; In the formula, U ( t ) contains the frequency response functions of each observation point in the shedding mechanism when different excitation sources are input, L ( t ) contains the frequency response functions of each observation point in the beat-up mechanism when different excitation sources are input, P ( t ) contains the frequency response functions of each observation point in the let-off mechanism when different excitation sources are input, u ij (t) is t at time j the frequency response function output by the corresponding i th observation point in the shedding mechanism when the l ij (t) is the frequency response function output by the corresponding j th observation point in the beat-up mechanism when the i th excitation source is input at time t, p ij (t) is the frequency response function output by the corresponding j th observation point in the shedding mechanism when the i th excitation source is input at time t, t is time, jt ui is the frequency response value output by the j th output in the let-off mechanism, jt li is the frequency response value output by the j th output in the beat-up mechanism, jt pi is the frequency response value output by the j th output in the shedding mechanism, t c is the cut-off frequency, tc is the cut-off frequency.

[0012] Based on the above technical solutions, preferably, the suspension element includes a connecting member of the loom and a vibration source support. The connecting member is a rigid connecting member. Each connecting member includes a vibration source mounting side mounting point and a wallboard side mounting point. The vibration source support includes a cam box support and a motor support. Each vibration source support includes a vibration source mounting side mounting point and a wallboard side mounting point. Among them, the vibration source mounting side mounting point is the active end, and the wallboard side mounting point is the passive end.

[0013] Based on the above technical solutions, preferably, in step S4, the introduced yarn tension and air damping correction parameters are used to correct the dynamic stiffness model of the suspension element, and the expression is:

[0014] In the formula, m ix is the dynamic stiffness in the i direction generated by the weft yarn on the x th path, m iy is the dynamic stiffness in the i direction generated by the warp yarn on the y th path, c iax is the air damping in the i direction on the x th path, c iay is the air damping in the i direction on the y th path, k i is the static stiffness of the suspension on the i th path. λ1 is the correction parameter of the air damping generated when the yarn moves in the air flow, and λ2 is the correction parameter of the static stiffness under the influence of the yarn, ω is the frequency.

[0015] Based on the above technical solutions, preferably, in step S4, based on the corrected dynamic stiffness model, calculating the structural vibration load force transmitted by the suspension element to the passive end includes the following steps: According to the corrected dynamic stiffness model, calculate the structural vibration load force transmitted by the suspension element to the passive end, and the expression is:

[0016] In the formula, F i ( ω ) is the structural vibration load force applied to the i th degree of freedom at the frequency ω, aai ( ω ) is the acceleration of the active end at frequency ω . a pi ( ω ) is the acceleration of the passive end at frequency ω . K i ( ω ) is the dynamic stiffness of the mounting element; The structural vibration load of the air-jet loom is calculated by using the dynamic stiffness method of the mounting, and the dynamic responses of multiple degrees of freedom are obtained, expressed as:

[0017] In the formula, u q ( ω ) is the response of the system at the ω -th degree of freedom at frequency q . H qi ( ω ) is the frequency response function, indicating the response of the i -th degree of freedom when a unit force is applied to the q -th degree of freedom. F i ( ω ) is the structural vibration load force applied to the i -th degree of freedom at frequency ω, n is the total number of degrees of freedom in the system; The calculation expression of the structural vibration load force transmitted by the mounting element to the passive end and the modified dynamic stiffness model are substituted into the calculation expressions of the dynamic responses of different degrees of freedom to obtain the dynamic response of the system, and the expression is:

[0018] In the formula, G qi ( ω ) is the dynamic response of the system after the formula change, expressed as the response of the input force of the system at frequency ω . The dynamic response of the system is converted into a system linear matrix equation, and the expression is:

[0019] The least squares method is used to solve the system linear matrix equation to obtain the dynamic stiffness m i , damping c i and static stiffness k iThe values are respectively substituted into the structural vibration load force expression transmitted by the suspension element to the passive end and the dynamic stiffness model of the modified suspension element, and the structural vibration load force transmitted by the suspension element to the passive end is calculated.

[0020] On the basis of the above technical solution, preferably, in step S5, the structural vibration load force of the passive end is multiplied by the frequency response function of the corresponding path to calculate the contribution of each path, where the expression is: ; In the formula, y k ( ω ) represents the contribution of the transfer path, H ki ( ω ) is the frequency response function from the i th input point to the k th target point, indicating that when a unit force is applied at the i th input point, the response of the k th target point at frequency ω .

[0021] In a second aspect, the present invention also provides a system for analyzing the vibration transfer path of a jet loom frame, which is implemented by using the above-mentioned method for analyzing the vibration transfer path of a jet loom frame. The system includes: An acquisition module for acquiring the acceleration signals of the target reference point, the connection point of the vibration source path input, and the vibration source under the working conditions; A simulation test module for removing the active end excitation source, hammering the passive end position at the excitation points of the left and right wallboards, performing a system frequency response function test, and filtering the vibration data of the response points to obtain the system frequency response function; A modeling module for defining the transfer path of vibration from the excitation source through the connecting member to the target response point with the main motor and the cam box as the excitation sources, the suspension element as the connecting member, and the passive end of the wallboard as the target response point, and establishing an analysis model for the vibration transfer path of the jet loom; A calculation module for introducing the yarn tension and air damping correction parameters to correct the dynamic stiffness model of the suspension element, and calculating the structural vibration load force transmitted by the suspension element to the passive end based on the corrected dynamic stiffness model; A determination module for multiplying the structural vibration load force of the passive end by the frequency response function of the corresponding path, calculating the contribution of each path, comparing the magnitudes of the contributions of each path, and taking the path with the largest contribution as the vibration sensitive path.

[0022] In a third aspect, the present invention also provides a computer-readable storage medium, on which a program for analyzing the vibration transmission path of a air-jet loom frame is stored. When the program for analyzing the vibration transmission path of the air-jet loom frame is executed, the above-mentioned method for analyzing the vibration transmission path of the air-jet loom frame is realized.

[0023] The method and system for analyzing the vibration transmission path of the air-jet loom frame of the present invention have the following beneficial effects compared with the prior art: (1) By collecting the acceleration signals of the ultra-high-speed air-jet loom under working conditions, establishing and correcting the transmission path model, and accurately analyzing the vibration transmission path of the loom frame, the accurate identification of the vibration-sensitive path is realized. This not only improves the accuracy of vibration analysis but also provides support for the vibration reduction optimization of the loom, effectively improving the performance and service life of the loom. (2) By setting the attenuation coefficient and controlling the movement of the individual mechanism, the influence of each component on the system vibration is evaluated more accurately. The vibration responses of each moving mechanism are measured, and the relevant frequency response functions can be calculated for filtering the overall vibration signal to filter out the vibration influence of the moving system, obtaining a more accurate vibration signal of the excitation source, effectively reducing the vibration interference of the moving components, improving the authenticity of the transmission path signal, and providing data support for subsequent working condition load calculation. (3) After introducing the yarn tension and air damping correction parameters, the model can more comprehensively consider various physical effects during the working process of the air-jet loom, enabling the model to more accurately describe the dynamic behavior of the yarn, thereby improving the accuracy of the model. Description of the Drawings

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0025] Figure 1 It is a flowchart of a method for analyzing the vibration transmission path of an air-jet loom frame of the present invention; Figure 2 It is a schematic diagram of the vibration transmission path framework of a method for analyzing the vibration transmission path of an air-jet loom frame of the present invention; Figure 3 It is a schematic diagram of the vibration transmission path structure in an example of a method for analyzing the vibration transmission path of an air-jet loom frame of the present invention; Figure 4 It is a schematic diagram of the vibration transmission path structure in another example of a method for analyzing the vibration transmission path of an air-jet loom frame of the present invention. Detailed Embodiments

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0027] As Figures 1 - 4 shown, a method for analyzing the vibration transmission path of a projectile loom frame includes the following steps: S1. Obtain the acceleration signals of the target reference point, the connection point of the vibration source path input, and the vibration source under the working conditions.

[0028] Among them, in step S1, acceleration sensors are respectively arranged at the motor, the cam box, the beating-up mechanism, the shedding mechanism, the let-off mechanism, the main shaft vibration source, the passive ends of the left wallboard and the right wallboard, and the loom response points. Under the operating state of the projectile loom, vibration signals at different rotational speeds are collected, the vibration amplitude frequencies in the X, Y, and Z directions are obtained, and the root mean square value of the vibration acceleration is calculated for evaluating the vibration state of the loom.

[0029] Specifically, an SCM2E05 type LMS acquisition system and a three-phase piezoelectric acceleration sensor are used to collect acceleration signals. The sampling frequency is 1024HZ, and the test frequency range is 0 - 512HZ. Sensors are arranged at 60 points, including basic vibration sources such as motors and cams, moving vibration sources such as beating-up mechanisms, shedding mechanisms, and main shafts, passive ends such as the lower sides of the middle parts of the left wallboard and the right wallboard, and 4 evaluation reference points such as the front and back of the left wallboard and the front and back of the right wallboard. Under the operating state of the super-high-speed projectile loom, the LMS software is used to monitor and record the vibration amplitude frequencies in the X, Y, and Z directions at different rotational speeds of 500 - 1000 rpm, and the root mean square value of the vibration acceleration is processed, calculated, and integrated.

[0030] It should be noted that acceleration sensors are arranged at key positions, including vibration sources such as motors, cam boxes, beating-up mechanisms, shedding mechanisms, let-off mechanisms, and main shafts, as well as passive ends of the left and right wallboards and loom response points, to comprehensively monitor the vibrations generated during the operation of air-jet looms, so as to accurately evaluate their vibration states. The sampling frequency is set to 1024 HZ to ensure that high-frequency vibration signals can be captured. The test frequency range covers 0 - 512 HZ, which covers the main vibration frequencies during the operation of air-jet looms. Under the operating state of ultra-high-speed air-jet looms, the vibration signals at different rotational speeds are monitored and recorded, and the vibration amplitude frequencies in the X, Y, and Z directions are recorded, which respectively represent the vibration conditions of the loom in the horizontal, vertical, and front-back directions. The collected vibration signals are processed to calculate the root mean square value of the vibration acceleration at each point in each direction. This vibration evaluation index can reflect the energy and intensity of vibrations, and then the vibration state of the air-jet loom can be evaluated. If the RMS value exceeds the preset threshold, it indicates that the loom has excessive vibrations and needs to be inspected and maintained to ensure that the air-jet loom is in a stable operating state.

[0031] S2. Remove the active-end excitation source, hammer the passive-end positions at the excitation points of the left and right wallboards, conduct a system frequency response function test, and filter the vibration data at the response points to obtain the system frequency response function.

[0032] Among them, step S2 includes the following sub-steps: S21. Divide the moving components of the air-jet loom into shedding mechanisms, beating-up mechanisms, and let-off mechanisms, and set corresponding attenuation coefficients according to their respective positions corresponding to the loom frame. S22. Control the movement of a single mechanism by regulating the loom system, install acceleration sensors at the measurement points of each mechanism, hammer the passive-end positions at the excitation points of the left and right wallboards, collect the vibration response data under various working conditions of the air-jet loom, and use a low-pass filter to filter the vibration response data to establish the corresponding system frequency response function.

[0033] In the filter design of this embodiment, the frequency response describes the amplification or attenuation degree of the system for different frequency components. A low-pass filter will attenuate high-frequency components while keeping low-frequency components unchanged, and its frequency response is expressed as:

[0034] In the formula, j is the imaginary unit, ω c is the cut-off frequency, ω is the angular frequency; The main moving components of the air-jet loom have large vibrations and are divided into three parts, including the shedding mechanism, the beating-up mechanism, and the warp let-off mechanism. Accelerometers are installed at the key measurement points of each mechanism to collect the vibration response signals of the loom under various working conditions. As the distance from the vibration source increases, its vibration frequency, noise, amplitude, etc. will continue to decay, so as to more accurately evaluate the frequency response characteristics of the system.

[0035] In this embodiment, the set coefficient a is the attenuation coefficient of the shedding mechanism from the loom frame, b is the attenuation coefficient of the beating-up mechanism from the loom frame, c is the attenuation coefficient of the warp let-off mechanism from the loom frame, where a The value range of a is 0.32 ≤ b The value range of b is 0.42 ≤ c The value range of c is 0.54 ≤

[0036] The system frequency response function expression is established according to the positions of their respective corresponding loom frames as:

[0037] In the formula, f ( t ) is the system frequency response function corresponding to the air-jet loom at t moment, a is the attenuation coefficient of the shedding mechanism, U ( t ) is the frequency response data matrix of the shedding mechanism, b is the attenuation coefficient of the beating-up mechanism, L ( t ) is the frequency response data matrix of the beating-up mechanism, c is the attenuation coefficient of the warp let-off mechanism, P ( t ) is the frequency response data matrix of the warp let-off mechanism; Among them,

[0038] Among them: ; ; ; In the formula, U ( t ) includes the frequency response functions of each observation point in the shedding mechanism when different excitation sources are input, L ( t ) includes the frequency response functions of each observation point in the beating-up mechanism when different excitation sources are input,P ( t ) includes the frequency response functions of each observation point in the let-off mechanism when different excitation sources are input. u ij (t) is t the frequency response function output by the corresponding j th observation point in the shedding mechanism when the i th excitation source is input at time t. l ij (t) is the frequency response function output by the corresponding j th observation point in the beating-up mechanism when the i th excitation source is input at time t. p ij (t) is the frequency response function output by the corresponding j th observation point in the shedding mechanism when the i th excitation source is input at time t. t t is time, jt ui is the frequency response value of the j th output in the let-off mechanism. jt li is the frequency response value of the j th output in the beating-up mechanism. jt pi is the frequency response value of the j th output in the shedding mechanism. t c is the cut-off frequency. t c is the cut-off frequency, where the cut-off frequency is the frequency at which the amplitude of the output signal drops to -3 dB (i.e., approximately 0.707 times) of the amplitude of the input signal.

[0039] In this embodiment, by setting the attenuation coefficient and controlling the movement of the mechanism separately, the influence of each component on the system vibration can be evaluated more accurately. The vibration responses of each moving mechanism can be measured, and the relevant frequency response functions can be calculated for filtering the overall vibration signal to filter out the influence of the movement system vibration, obtain a more accurate vibration signal of the excitation source, effectively reduce the vibration interference of the moving components, improve the authenticity of the transmission path signal, and provide data support for the subsequent calculation of the working condition load.

[0040] S3. Taking the main motor, cam box, small pulley, and large pulley as excitation sources, taking the suspension element as the connecting piece, and taking the passive end of the wallboard as the target response point, define the transmission path of vibration from the excitation source through the connecting piece to the target response point, and establish an analysis model for the vibration transmission path of the air-jet loom. The suspension element in this embodiment includes a connecting member of the loom and a vibration source support. The connecting member is a rigid connecting member. Each connecting member includes a vibration source mounting side mounting point and a wallboard side mounting point. The vibration source support includes a cam box support and a motor support. Each vibration source support includes a vibration source mounting side mounting point and a wallboard side mounting point. Among them, the vibration source mounting side mounting point is the active end, and the wallboard side mounting point is the passive end.

[0041] S4. Introduce the yarn tension and air damping correction parameters, correct the dynamic stiffness model of the suspension element, and calculate the structural vibration load force transmitted from the suspension element to the passive end based on the corrected dynamic stiffness model.

[0042] Among them, considering that during the operation of the air-jet loom, the high-speed air flow ejected by the nozzle will generate a thrust on the yarn, causing it to move along a predetermined path. The warp yarn maintains a certain tension during the weaving process, which will generate a certain tension on the weft yarn. When the weft yarn passes through the warp yarn, friction will be generated between the yarns. This friction can be regarded as a kind of damping. When the yarn moves in the air flow, the resistance generated by the air on it is also a form of damping. Therefore, the correction parameter λ1 is introduced. At the same time, in addition to damping, in order to eliminate the influence of the yarn, the static stiffness correction parameter λ2 under the influence of the yarn is introduced.

[0043] Introduce the yarn tension and air damping correction parameters, and correct the dynamic stiffness model of the suspension element. The expression is:

[0044] In the formula, m ix is the dynamic stiffness in the i direction generated by the weft yarn on the x th path, m iy is the dynamic stiffness in the i direction generated by the warp yarn on the y th path, c iax is the air damping in the i direction on the x th path, c iay is the air damping in the i direction on the y th path, k i is the static stiffness of the suspension on the i th path. λ1 is the correction parameter of the air damping generated when the yarn moves in the air flow, and λ2 is the static stiffness correction parameter under the influence of the yarn, ω is the frequency.

[0045] After introducing the yarn tension and air damping correction parameters in this embodiment, the model can more comprehensively consider various physical effects during the operation of the air-jet loom, such as yarn tension, frictional damping, and air resistance, enabling the model to more accurately describe the dynamic behavior of the yarn, thereby improving the accuracy of the model.

[0046] In this embodiment, based on the corrected dynamic stiffness model, the structural vibration load force transmitted from the suspension element to the passive end is calculated, including the following steps: According to the corrected dynamic stiffness model, the structural vibration load force transmitted from the suspension element to the passive end is calculated, and the expression is:

[0047] In the formula, F i ( ω ) is the structural vibration load force applied to the i th degree of freedom at frequency ω, a ai ( ω ) is the acceleration of the active end at frequency ω ω, a pi ( ω ) is the acceleration of the passive end at frequency ω ω, K i ( ω ) is the dynamic stiffness of the suspension element; Using the suspension dynamic stiffness method to calculate the structural vibration load of the air-jet loom, the dynamic responses of multiple degrees of freedom are obtained, expressed as:

[0048] In the formula, u q ( ω ) is the response of the ω th degree of freedom of the system at frequency q ω, H qi ( ω ) is the frequency response function, indicating the response of the i th degree of freedom when a unit force is applied to the q th degree of freedom, F i ( ω ) is the structural vibration load force applied to the i th degree of freedom at frequency ω, n is the total number of degrees of freedom in the system; The calculation expression of the structural vibration load force for transmitting the suspension element to the passive end and the modified dynamic stiffness model are substituted into the calculation expressions of the dynamic responses with different degrees of freedom to obtain the dynamic response of the system. The expression is as follows:

[0049] In the formula, G qi ( ω ) is the dynamic response of the system after the formula change, which represents the response of the system input force at the frequency ω ; The dynamic response of the system is converted into a system linear matrix equation. The expression is as follows: ; The least squares method is used to solve the system linear matrix equation to obtain the dynamic stiffness m i , damping c i and static stiffness k i values of each suspension element, and substitute them into the expression of the structural vibration load force transmitted by the suspension element to the passive end and the modified dynamic stiffness model of the suspension element respectively to calculate the structural vibration load force transmitted by the suspension element to the passive end.

[0050] Among them, the data collected under the operating conditions of the reference point or the target point are subjected to order tracking analysis. The response signal of the reference point or the target point contains ω order slices, and each slice contains r rpm speed sampling points. Then the system matrix equation is expressed in a block form as follows:

[0051] Among them, ; ; ; In the formula, , o m is the number of order slices, rpm x is the rotational speed of the main shaft of the motor housing.

[0052] Considering all reference points u q (q = 1, 2, 3, 4....., v ), then the block expression form of the system matrix equation is extended to the overall equation of the system. The expression is as follows: ​

[0053] In the formula, , .

[0054] The system linear matrix equation is solved by the least squares method, and the results are as follows:

[0055] In the formula, X The solution results are the dynamic stiffness, damping, and static stiffness of each mounting element, and + is the matrix generalized inverse operator.

[0056] S5. Multiply the structural vibration load force at the passive end by the frequency response function of the corresponding path, calculate the contribution amount of each path, compare the magnitudes of the contribution amounts of each path, and take the path with the largest contribution amount as the vibration-sensitive path.

[0057] Among them, the expression in step S5 is:

[0058] In the formula, y k ( ω ) represents the contribution amount of the transfer path, H ki ( ω ) is the frequency response function from the i th input point to the k th target point, indicating the response of the i th target point at the frequency k when a unit force is applied at the ω th input point.

[0059] In this embodiment, a filtering module is added to filter out the influence of vibrating components; the acceleration signals of the target reference point, the input connection of the vibration source path, and vibration sources such as motors and cam boxes are collected under the working conditions; the system frequency response function is tested by hammering the position of the passive end at the excitation points of the left and right wall panels with the active end excitation sources such as motors removed; the influence of the yarn tension is corrected by inserting correction parameters, and a vibration transfer path analysis model of the air-jet loom is established; the load calculation under the operating conditions is performed by identifying the model; the path contribution amount of each target point is obtained by multiplying the passive end load by the corresponding path frequency response function; the vibration-sensitive path is determined by comparing the magnitudes of the contribution amounts of each path. This method extends the traditional TPA method, introduces filtering processing and inserts correction parameters, improves the accuracy and precision of the vibration transfer path analysis, establishes a vibration analysis model of the excitation source - transfer path - target response point, visualizes the results of the path contribution amount, and lays a foundation for the vibration reduction optimization of the loom.

[0060] Second aspect, the present invention further provides a system for analyzing the vibration transmission path of a air-jet loom frame, which is implemented by using the above-mentioned method for analyzing the vibration transmission path of the air-jet loom frame. The system includes: An acquisition module, configured to acquire the acceleration signals of the target reference point, the input connection of the vibration source path, and the vibration source under working conditions; A simulation test module, configured to remove the active end excitation source, hammer the passive end position of the left and right wallboard excitation points, perform a system frequency response function test, filter the vibration data of the response points, and obtain the system frequency response function; A modeling module, configured to define the vibration transmission path from the excitation source through the connecting member to the target response point, with the main motor and the cam box as the excitation sources, the suspension elements as the connecting members, and the passive end of the wallboard as the target response point, and establish an analysis model for the vibration transmission path of the air-jet loom; A calculation module, configured to introduce the yarn tension and air damping correction parameters, correct the dynamic stiffness model of the suspension element, and calculate the structural vibration load force transmitted from the suspension element to the passive end based on the corrected dynamic stiffness model; A determination module, configured to multiply the structural vibration load force of the passive end by the frequency response function of the corresponding path, calculate the contribution of each path, compare the magnitudes of the contributions of each path, and take the path with the largest contribution as the vibration sensitive path.

[0061] It should be noted that this system corresponds to the above-mentioned method for analyzing the vibration transmission path of the air-jet loom frame. All implementation manners in the above method embodiments are applicable to the embodiments of this system and can achieve the same technical effects.

[0062] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0063] Those skilled in the art can clearly understand that for the convenience and conciseness of description, the specific working processes of the above-described system and modules can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein.

[0064] In the embodiments provided by the present invention, it should be understood that the disclosed systems and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces. The indirect couplings or communication connections of the devices or units can be in electrical, mechanical or other forms.

[0065] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0066] In addition, in each embodiment of the present invention, the functional units can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit.

[0067] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or a part of this technical solution can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, ROM, RAM, magnetic disks, or optical discs that can store program codes.

[0068] In addition, it should be noted that in the system and method of the present invention, obviously, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations shall be regarded as equivalent solutions of the present invention. Moreover, the steps of performing the above series of processes can naturally be executed chronologically in the described order, but it is not necessary to be executed in chronological order. Some steps can be executed in parallel or independently of each other. For those of ordinary skill in the art, it is understandable that all or any steps or components of the method and device of the present invention can be implemented in any computing device (including processors, storage media, etc.) or a network of computing devices in the form of hardware, firmware, software, or a combination thereof, which can be achieved by those of ordinary skill in the art using their basic programming skills after reading the description of the present invention.

[0069] Therefore, the object of the present invention can also be achieved by running a program or a set of programs on any computing system. The computing system can be a well-known general system. Therefore, the object of the present invention can also be achieved only by providing a program product containing program codes for implementing the method or device. That is to say, such a program product also constitutes the present invention, and the storage medium storing such a program product also constitutes the present invention. Obviously, the storage medium can be any well-known storage medium or any storage medium developed in the future. It should also be noted that in the device and method of the present invention, obviously, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations shall be regarded as equivalent solutions of the present invention. Moreover, the steps of performing the above series of processes can naturally be executed chronologically in the described order, but it is not necessary to be executed in chronological order. Some steps can be executed in parallel or independently of each other.

[0070] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for analyzing the vibration transmission path of a jet loom frame, characterized in that It includes the following steps: S1. Obtain the acceleration signals of the target reference point, the input connection of the vibration source path, and the vibration source under the working conditions; S2. Remove the active end excitation source, hammer the passive end positions of the left and right wallboard excitation points, conduct a system frequency response function test, filter the vibration data of the response points, and obtain the system frequency response function; S3. Take the main motor, cam box, small pulley, and large pulley as the excitation sources, take the suspension components as the connecting parts, take the passive end of the wallboard as the target response point, define the transmission path of vibration from the excitation source through the connecting parts to the target response point, and establish an analysis model for the vibration transmission path of the air-jet loom; S4. Introduce the yarn tension and air damping correction parameters, correct the dynamic stiffness model of the suspension components, and calculate the structural vibration load force transmitted from the suspension components to the passive end based on the corrected dynamic stiffness model; S5. Multiply the structural vibration load force at the passive end by the frequency response function of the corresponding path, calculate the contribution of each path, compare the magnitudes of the contributions of each path, and take the path with the largest contribution as the vibration-sensitive path.

2. The method for analyzing the vibration transmission path of a jet loom frame according to claim 1, wherein: In step S1, for obtaining the acceleration signals of the target reference point, the input connection of the vibration source path, and the vibration source under the working conditions, acceleration sensors are respectively arranged at the main motor, cam box, beating-up mechanism, shedding mechanism, let-off mechanism, and the vibration sources of the main shaft, as well as the passive ends of the left and right wallboards and the loom response points. Under the operating state of the air-jet loom, vibration signals at different speeds are collected, the vibration amplitude frequencies in the X, Y, and Z directions are obtained, and the root mean square value of the vibration acceleration is calculated for evaluating the vibration state of the loom.

3. The method for analyzing the vibration transmission path of the air-jet loom frame according to claim 2, characterized in that: In step S2, for removing the active end excitation source, hammering the passive end positions of the left and right wallboard excitation points, conducting a system frequency response function test, collecting the vibration response data of each response point, and filtering the vibration response data to obtain the frequency response function of the system, it includes the following sub-steps: S21. Divide the moving components of the air-jet loom into the shedding mechanism, beating-up mechanism, and let-off mechanism, and set the corresponding attenuation coefficients according to their respective positions corresponding to the loom frame; S22. Control the movement of a single mechanism through the loom system, install acceleration sensors at the measurement points of each mechanism, hammer the passive end positions of the left and right wallboard excitation points, collect the vibration response data of the air-jet loom under various working conditions, and filter the vibration response data using a low-pass filter to establish the corresponding system frequency response function.

4. The method for analyzing the vibration transmission path of the air-jet loom frame according to claim 3, characterized in that: The expression of the system frequency response function is: ； In the formula, f ( t ) is the system frequency response function corresponding to the air-jet loom at t moment, a is the attenuation coefficient of the shedding mechanism from the loom frame, U ( t ) is the frequency response data matrix of the shedding mechanism, b is the attenuation coefficient of the beat-up mechanism from the loom frame, L ( t ) is the frequency response data matrix of the beat-up mechanism, c is the attenuation coefficient of the let-off mechanism from the loom frame, P ( t ) is the frequency response data matrix of the let-off mechanism; Among them, ； Where: ； ； ； Wherein, U ( t ) contains the frequency response functions of each observation point in the shedding mechanism when different excitation sources are input, L ( t ) contains the frequency response functions of each observation point in the beating-up mechanism when different excitation sources are input, P ( t ) contains the frequency response functions of each observation point in the let-off mechanism when different excitation sources are input, u ij (t) is the frequency response function output by the corresponding j th observation point in the shedding mechanism when the i th excitation source is input at time t, l ij (t) is the frequency response function output by the corresponding j th observation point in the beating-up mechanism when the i th excitation source is input at time t, p ij (t) is the frequency response function output by the corresponding j th observation point in the shedding mechanism when the i th excitation source is input at time t, t is time, jt ui is the frequency response value of the j th output in the let-off mechanism, jt li is the frequency response value of the j th output in the beating-up mechanism, jt pi is the frequency response value of the j th output in the shedding mechanism, t c is the cut-off frequency.

5. The method for analyzing the vibration transmission path of a jet loom frame according to claim 1, characterized in that: The suspension components include the connecting parts of the loom and the vibration source supports. The connecting parts are rigid connecting parts. Each connecting part includes a mounting point on the vibration source installation side and a mounting point on the wallboard side. The vibration source supports include the cam box support and the motor support. Each vibration source support includes a mounting point on the vibration source installation side and a mounting point on the wallboard side. Among them, the mounting point on the vibration source installation side is the active end, and the mounting point on the wallboard side is the passive end.

6. The method for analyzing the vibration transmission path of the air-jet loom frame according to claim 1, characterized in that: In step S4, for introducing the yarn tension and air damping correction parameters and correcting the dynamic stiffness model of the suspension components, the expression is: ； Wherein, m ix is the dynamic stiffness in the i direction generated by the weft yarn on the x th path, m iy is the dynamic stiffness in the i direction generated by the warp yarn on the y th path, c iax is the air damping in the i direction for the x th path, c iay is the air damping in the i direction for the y th path, k i is the static stiffness of the suspension on the i th path, λ1 is the correction parameter of the air damping generated when the yarn moves in the air flow, and λ2 is the correction parameter of the static stiffness under the influence of the yarn, ω is the frequency.

7. The method for analyzing the vibration transmission path of the air-jet loom frame according to claim 6, characterized in that: In step S4, for calculating the structural vibration load force transmitted from the suspension components to the passive end based on the corrected dynamic stiffness model, it includes the following steps: According to the modified dynamic stiffness model, calculate the structural vibration load force transmitted by the mounting element to the passive end, and the expression is: ； wherein, F i ( ω ) is the structural vibration load force applied to the i th degree of freedom at frequency ω, a ai ( ω ) is the acceleration of the active end at frequency ω , a pi ( ω ) is the acceleration of the passive end at frequency ω , K i ( ω ) is the dynamic stiffness of the suspension element; Adopt the mounting dynamic stiffness method to calculate the structural vibration load of the air-jet loom, and obtain the dynamic responses of multiple degrees of freedom, which are expressed as: ； wherein, u q ( ω ) is the response of the ω -th degree of freedom of the system at frequency q , H qi ( ω ) is the frequency response function, indicating the response of the i -th degree of freedom when a unit force is applied to the q -th degree of freedom, F i ( ω ) is the structural vibration load force applied to the i -th degree of freedom at frequency ω, n is the total number of degrees of freedom in the system; Substitute the calculation expression of the structural vibration load force transmitted by the mounting element to the passive end and the modified dynamic stiffness model into the calculation expressions of the dynamic responses of different degrees of freedom to obtain the dynamic response of the system, and the expression is: ； In the formula, G qi ( ω ) is the dynamic response of the system after the formula change, expressed as the response of the system input force at the frequency ω ; Convert the dynamic response of the system into a system linear matrix equation, and the expression is: ； Solve the system linear matrix equation using the least squares method to obtain the dynamic stiffness of each mounting element m i , damping c i and static stiffness k i values, and substitute them into the structural vibration load force expression transmitted from the mounting element to the passive end and the dynamic stiffness model of the modified mounting element respectively to calculate the structural vibration load force transmitted from the mounting element to the passive end.

8. The method for analyzing the vibration transmission path of the air-jet loom frame according to claim 7, characterized in that: In step S5, multiply the structural vibration load force of the passive end by the frequency response function of the corresponding path to calculate the contribution of each path. Among them, the expression is: ； In the formula, y k ( ω ) represents the contribution of the transfer path, H ki ( ω ) is the frequency response function from the i th input point to the k th target point, indicating the response of the i th target point at the frequency k when a unit force is applied at the ω th input point.

9. A vibration transmission path analysis system for a projectile loom frame, which is implemented by using the vibration transmission path analysis method for a projectile loom frame according to any one of claims 1-8, characterized in that: The system includes: An acquisition module, which is used to obtain the acceleration signals of the target reference point, the input connection of the vibration source path, and the vibration source under the working conditions; A simulation test module, which is used to remove the active end excitation source, hammer the passive end position at the excitation points of the left and right wallboards, conduct system frequency response function tests, and filter the vibration data of the response points to obtain the system frequency response function; A modeling module, which is used to define the vibration transmission path from the excitation source through the connecting piece to the target response point with the main motor and the cam box as the excitation sources, the mounting element as the connecting piece, and the passive end of the wallboard as the target response point, and establish an air-jet loom vibration transmission path analysis model; A calculation module, which is used to introduce the yarn tension and air damping correction parameters to correct the dynamic stiffness model of the mounting element, and calculate the structural vibration load force transmitted by the mounting element to the passive end based on the corrected dynamic stiffness model; A determination module, which is used to multiply the structural vibration load force of the passive end by the frequency response function of the corresponding path to calculate the contribution of each path, compare the magnitudes of the contributions of each path, and take the path with the largest contribution as the vibration sensitive path.

10. A computer-readable storage medium, characterized in that, A program for the method of analyzing the vibration transmission path of the air-jet loom frame is stored on the storage medium. When the program for the method of analyzing the vibration transmission path of the air-jet loom frame is executed, it implements the method of analyzing the vibration transmission path of the air-jet loom frame according to any one of claims 1 to 8.

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