A method and system for testing dynamic performance of equipment based on large thrust vibration table

Abstract

The present application belongs to the technical field of vibration table, and discloses a kind of equipment dynamic performance inspection method and system based on large thrust vibration table.The inspection method steps include: subject equipment installation and sensor arrangement;Frequency sweep test is carried out on subject equipment;Subject equipment modal parameter identification;Vibration loading test is carried out on subject equipment;Vibration response inspection is carried out on subject equipment.The inspection system includes vibration generator, auxiliary support mechanism, extension table, equipment fixing mechanism, subject equipment, vibration monitoring system, control and data analysis system.The present application carries out frequency sweep test and vibration loading test on subject equipment whole machine by using large thrust vibration table, not only can obtain the modal parameters such as inherent frequency and damping ratio of equipment, but also can test the keeping ability of equipment dynamic performance, provide test basis for subsequent optimization and improvement of equipment.The present application can be used for the dynamic performance inspection of high-end complex equipment such as numerical control machine tool and industrial robot.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of vibration tables, and particularly relates to a method and system for inspecting dynamic performance of equipment based on a large-thrust vibration table. BACKGROUND

[0002] Dynamic performance is one of important indexes for measuring the operation efficiency of equipment under actual service conditions, and directly affects the reliability and operation life of the equipment in the service process. The dynamic performance describes the response law of the overall structure of the equipment under dynamic load, and can be quantitatively characterized by modal parameters such as natural frequency, damping ratio and modal shape.

[0003] The test of dynamic performance can provide data support for equipment design optimization and fault warning, and it is of great significance to study the dynamic performance test method. At present, the commonly used modal parameter test methods such as hammering method and exciter method are widely applied. On this basis, combined with the structural characteristics and parameter requirements of the equipment to be tested, individual special dynamic performance test methods are proposed. For example, in 2023, Zou Jie et al. of Huazhong University of Science and Technology disclosed a method and system for testing dynamic performance of five-axis machine tools in patent CN202310121156.4, which obtains the dynamic error of the machine tool by testing the difference between the low-speed motion and the high-speed motion of the machine tool; in 2024, Wang Luzi et al. of Kunming University of Science and Technology disclosed a dynamic performance test device for industrial robots in patent CN202411587496.7, which tests the structural stiffness of the industrial robot by applying load to the robot in the fast motion and static states.

[0004] Through the analysis of the existing research on the dynamic performance test of equipment, it is found that the hammering method and the exciter method have been widely applied due to their portability, low cost and other characteristics. However, for the dynamic performance test of large and complex equipment, these test methods also have the disadvantages of insufficient excitation, excessive dependence on manual operation and complex operation. Therefore, the application provides a method for inspecting dynamic performance of equipment based on a large-thrust vibration table, which can fully stimulate the dynamic response of the whole equipment, obtain the modal parameters such as natural frequency and damping ratio of the whole equipment, and test the dynamic performance retention capability of the whole equipment after vibration loading. SUMMARY

[0005] In order to solve the above technical problems, a method and system for inspecting dynamic performance of equipment based on a large-thrust vibration table are provided.

[0006] The technical scheme of the application is as follows:

[0007] A method for inspecting dynamic performance of equipment based on a large-thrust vibration table, comprising the following steps:

[0008] Step 1: installation and fixation of the test equipment and arrangement of sensors;

[0009] The test equipment is installed on the table surface of the large thrust vibration table through the tooling to simulate the actual use installation mode; the test equipment is in the energized standby idle state during the test, so that the test equipment is in the attitude position under the actual working condition, and the attitude position is recorded; the acceleration sensor is arranged on the table surface of the large thrust vibration table, and is used for controlling the large thrust vibration table to exert vibration excitation on the test equipment; the acceleration sensor is arranged on the test equipment, and is used for monitoring the response of the test equipment under the vibration excitation;

[0010] Step two, the frequency sweeping test is carried out on the test equipment;

[0011] The frequency sweeping test is carried out on the test equipment by using the large thrust vibration table, the frequency range, acceleration and frequency sweeping speed of the frequency sweeping test are set, the vibration excitation signal of the large thrust vibration table and the response signal of the test equipment are collected in real time through the acceleration sensor, and the frequency spectrum diagram of the vibration response of the test equipment is drawn;

[0012] Step three, the modal parameter identification of the test equipment;

[0013] For the resonance frequency in the frequency spectrum diagram, the amplitude ratio at each resonance frequency is calculated by using formula (1), which is used to describe the prominence of the resonance peak of the test equipment relative to the excitation value of the vibration table;

[0014] (1),

[0015] In the formula, is the amplitude ratio, is the amplitude peak at the resonance frequency, is the excitation amplitude of the large thrust vibration table;

[0016] The quality factor at each resonance frequency is calculated by using formula (2), which is used to describe the sharpness of the resonance peak of the test equipment;

[0017] (2),

[0018] In the formula, is the quality factor, is the resonance frequency, is the difference between the upper and lower limit frequencies when the amplitude is reduced to ; ; ;

[0019] If the amplitude ratio and the quality factor are met at the same time, the resonance frequency is considered as the natural frequency of the test equipment;

[0020] ​The natural frequency of the test equipment is calculated by formula (3) The corresponding damping ratio ;

[0021] (3)

[0022] Step four, the test equipment is subjected to vibration loading test;

[0023] The test equipment is subjected to long-time vibration loading test at each natural frequency identified in step three by using a large thrust vibration table; the test equipment needs to keep idling while being subjected to vibration loading until the loading time reaches the set value;

[0024] Step five, the test equipment is subjected to vibration response inspection;

[0025] After the vibration loading test in step four, the test equipment is subjected to frequency sweep test again, so that the attitude position of the test equipment is the same as that in step two, and the same frequency sweep test parameters as those in step two are used; according to the results of the two frequency sweep tests, formula (4) and formula (5) are used to calculate the frequency shift and amplitude change rate at the resonance frequency of the test equipment, respectively.

[0026] (4)

[0027] In the formula, is the frequency shift, is the resonance frequency of the frequency sweep test in step two, is the resonance frequency of the frequency sweep test in this step;

[0028] (5)

[0029] In the formula, is the amplitude change rate, is the acceleration peak value at the resonance frequency of the frequency sweep test in step two, is the acceleration peak value at the resonance frequency of the frequency sweep test in this step;

[0030] If the calculation result meets the frequency shift or the amplitude change rate , it is considered that the frequency sweep test result of the test equipment has changed significantly, which indicates that there is a weak link in the structure of the test equipment, and the test equipment needs to be adjusted and re-inspected; if the frequency sweep test result has not changed significantly, the inspection process is ended.

[0031] The application discloses an equipment dynamic performance inspection system based on a large-thrust vibration table, and belongs to the field of equipment dynamic performance inspection.

[0032] The application has the beneficial effects that the equipment dynamic performance inspection method is suitable for the inspection of the dynamic performance of large and complex equipment such as machine tools and robots, the dynamic response of the equipment can be fully stimulated by performing a sweep-frequency test on the equipment by using the large-thrust vibration table, and the dynamic performance maintenance capability of the equipment in the service process can be inspected by performing a vibration loading test on the equipment, so that the potential weak points of the equipment structure are exposed, and data support is provided for the improvement and optimization of the equipment. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 It is a dynamic performance inspection flowchart of equipment based on a large-thrust vibration table.

[0034] Figure 2 It is a schematic diagram of the equipment dynamic performance inspection system based on the large-thrust vibration table.

[0035] Figure 3 It is a structural schematic diagram of the equipment fixing mechanism.

[0036] Figure 4 It is a sweep-frequency test result schematic diagram of the equipment based on the large-thrust vibration table.

[0037] In the figure: 1 vibration generator; 2 auxiliary support mechanism; 3 extended table top; 4 equipment fixing mechanism; 5 test equipment; 6 vibration monitoring system; 7 control and data analysis system. DETAILED DESCRIPTION

[0038] The specific implementation mode of the application is further illustrated below in combination with the drawings and technical solutions.

[0039] The implementation mode of the application is illustrated in detail by taking the dynamic performance inspection of a numerical control machine tool as an example.

[0040] Step one, test equipment installation and fixing and sensor arrangement

[0041] The numerical control machine tool is fixed to the large-thrust vibration table extension table 3 through the equipment fixing mechanism 4, and the numerical control machine tool is adjusted to be horizontal; each feed shaft of the numerical control machine tool is adjusted to a conventional working position, the position coordinates of each shaft of the numerical control machine tool are recorded, and the numerical control machine tool is in a powered standby idle state; 8 acceleration sensors are arranged on the extension table 3, which are used to collect and control the vibration excitation of the vibration table on the numerical control machine tool; 1 acceleration sensor is arranged on the bed, column, worktable and spindle box of the numerical control machine tool respectively, which is used to monitor the response signal of the numerical control machine tool under vibration excitation.

[0042] Step two, the frequency sweeping test is carried out on the test equipment;

[0043] The frequency sweeping test is carried out on the numerical control machine tool using the vibration table, the frequency range of the frequency sweeping test is set to 10-100Hz, the acceleration is 0.2g, and the frequency sweeping speed is 0.5 octave / min; the excitation signal of the vibration table and the response signal of the numerical control machine tool are collected in real time through the acceleration sensor, and the frequency spectrum diagram of the vibration response of the numerical control machine tool is drawn.

[0044] Step three, modal parameter identification of the test equipment;

[0045] For the resonance frequency in the frequency spectrum diagram, the amplitude ratio is calculated by formula (1), and the quality factor is calculated by formula (2); after calculation, it is considered that 61.562Hz and 81.727Hz are the natural frequencies of the numerical control machine tool in the frequency range of the frequency sweeping test; the damping ratio corresponding to each natural frequency is calculated by formula (3), the damping ratio corresponding to 61.562Hz is 0.11, and the damping ratio corresponding to 81.727Hz is 0.08.

[0046] Step four, the vibration loading test is carried out on the test equipment;

[0047] The vibration loading test is carried out on the numerical control machine tool at two frequencies of 61.562Hz and 81.727Hz using the vibration table, the vibration acceleration is set to 0.2g, and the vibration loading duration at each frequency is 3h; at the same time of vibration loading, the numerical control machine tool running program is compiled, so that each feed shaft of the numerical control machine tool feeds at high speed, and the feed speed of each shaft is set to 5000mm / min.

[0048] Step five, vibration response inspection is carried out on the test equipment.

[0049] After the vibration loading test of step four is finished, the frequency sweep test is carried out again on the numerical control machine tool, the position coordinates of each feed axis of the numerical control machine tool are adjusted to be the same as those in step two, the frequency range of the frequency sweep test is set to be 10-100 Hz, the acceleration is 0.2 g, the sweep speed is 0.5 octave / min, and the frequency spectrum diagram of the numerical control machine tool after vibration loading is obtained; the frequency offset and the amplitude change rate of the two frequency sweep test results of the numerical control machine tool are calculated according to formulas (4) and (5), it is found that the amplitude change rate corresponding to the frequency 81.727 Hz is about 34%, the change of the two frequency sweep test results of the numerical control machine tool is relatively obvious, and it is indicated that there is a weak link in the structure of the numerical control machine tool, and the numerical control machine tool needs to be adjusted.

[0050] Finally, it should be pointed out that: the above examples are only used to illustrate the technical solutions of the present application, but not to limit it. Although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features, and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A large thrust vibration table based equipment dynamic performance test method, characterized in that: The steps are as follows: Step one, test equipment installation and sensor arrangement; The test equipment is installed on the table surface of the large thrust vibration table through the tooling, simulating the actual use installation mode; the test equipment is in the power-on standby idle state during the test process, so that the test equipment is in the attitude position under the actual working condition, and the attitude position is recorded; the acceleration sensor is arranged on the table surface of the large thrust vibration table, which is used for controlling the large thrust vibration table to apply vibration excitation to the test equipment; the acceleration sensor is arranged on the test equipment, which is used for monitoring the response of the test equipment under vibration excitation; Step two, frequency sweep test of the test equipment; The frequency sweep test of the test equipment is carried out by using the large thrust vibration table, the frequency range, acceleration and sweep speed of the frequency sweep test are set, the vibration excitation signal of the large thrust vibration table and the response signal of the test equipment are collected in real time through the acceleration sensor, and the frequency spectrum diagram of the vibration response of the test equipment is drawn; Step three, modal parameter identification of the test equipment; For the resonance frequency in the frequency spectrum diagram, the amplitude ratio at each resonance frequency is calculated by formula (1), which is used to describe the prominence of the resonance peak of the test equipment relative to the excitation value of the vibration table; ， where A is the amplitude ratio, A max is the amplitude peak at the resonance frequency, A ref is the excitation amplitude of the large thrust shaker; The quality factor at each resonance frequency is calculated by formula (2), which is used to describe the sharpness of the resonance peak of the test equipment; ， In the formula, Q is a quality factor, f0 is a resonance frequency, Δf is the difference between the upper and lower limit frequencies f2 and f1 at which the amplitude drops to 1 / e, i.e. ; If the amplitude ratio A > 5 and the quality factor Q > 5 are satisfied at the same time, the resonance frequency is considered as the natural frequency f of the test equipment n ; The natural frequency f of the subject equipment is calculated using equation (3) n The corresponding damping ratio ζ; ； Step four, vibration loading test of the test equipment; The vibration loading test of the test equipment is carried out at each natural frequency identified in step three by using the large thrust vibration table; the test equipment needs to keep idle running while the vibration loading is carried out, until the loading time reaches the set value; Step five, vibration response inspection of the test equipment; After the vibration loading test in step four is completed, the frequency sweep test of the test equipment is carried out again, so that the attitude position of the test equipment is the same as that in step two, and the same frequency sweep test parameters as in step two are used; according to the results of the two frequency sweep tests, the frequency offset and amplitude change rate at the resonance frequency of the test equipment are calculated by formula (4) and formula (5) respectively; ； In the formula, L f is the frequency offset, f a is the resonance frequency of the step two sweep test, f b is the resonance frequency of the sweep test of this step; ； wherein R A is the rate of change of amplitude, A a is the peak acceleration at the resonant frequency of the step two sweep test, A b is the peak acceleration at the resonant frequency of the step two sweep test, A If the calculation result meets the frequency deviation L f > 2 Hz or the amplitude change rate R A > 15%, it is considered that the sweep frequency test result of the test equipment has changed significantly, indicating that there is a weak link in the structure of the test equipment, and the test equipment needs to be adjusted and retested; if the sweep frequency test result does not change significantly, the test process ends.

2. A large thrust vibration table based equipment dynamic performance test system using the large thrust vibration table based equipment dynamic performance test method of claim 1, characterized in that, The equipment dynamic performance test system comprises a vibration generator, an auxiliary support mechanism, an extended table surface, an equipment fixing mechanism, a test equipment, a vibration monitoring system and a control and data analysis system; wherein the vibration generator is located in the auxiliary support mechanism, and is fixed and installed on the foundation in a center alignment manner with the auxiliary support mechanism, and is rigidly connected with the extended table surface, and supports the gravity and the force caused by vibration of the extended table surface together; the test equipment is located at the center position of the extended table surface, and is fixed on the extended table surface through the equipment fixing mechanism; the vibration monitoring system is installed on the extended table surface, and the control and data analysis system is located on the right side of the vibration generator and the auxiliary support mechanism on the foundation, and is used for controlling vibration excitation and analyzing vibration data.

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