Method and system for testing dynamic performance of equipment based on high-thrust vibration table

Abstract

The invention belongs to the technical field of vibration tables, and discloses an equipment dynamic performance test method and system based on a high-thrust vibration table. The testing method comprises the following steps: installing and fixing tested equipment and arranging a sensor; carrying out a frequency sweep test on the tested equipment; identifying modal parameters of the tested equipment; carrying out a vibration loading test on the tested equipment; and carrying out vibration response inspection on the tested equipment. The inspection system comprises a vibration generator, an auxiliary supporting mechanism, an expansion table top, an equipment fixing mechanism, tested equipment, a vibration monitoring system and a control and data analysis system. According to the method, the frequency sweeping test and the vibration loading test are carried out on the whole tested equipment by using the high-thrust vibration table, so that modal parameters such as the inherent frequency and the damping ratio of the equipment can be obtained, the retention capability of the dynamic performance of the equipment can be detected, and a test basis is provided for optimization and improvement of subsequent equipment. The method can be used for testing the dynamic performance of high-end complex equipment such as a numerical control machine tool and an industrial robot.

Description

Technical Field

[0001] The present invention belongs to the technical field of vibration tables, and in particular relates to a method and system for testing the dynamic performance of equipment based on a high-thrust vibration table. Background Art

[0002] Dynamic performance is a key indicator of equipment's operational effectiveness under actual service conditions, directly impacting its reliability and service life. Dynamic performance describes the response of the equipment's overall structure under dynamic loads and can typically be quantified using modal parameters such as natural frequency, damping ratio, and mode shape.

[0003] Dynamic performance testing can provide data support for equipment design optimization, fault warning, etc., and it is of great significance to study dynamic performance testing methods. At present, general modal parameter testing methods such as the hammer method and the vibrator method are widely used. On this basis, combined with the structural characteristics and parameter requirements of the equipment under test, some special dynamic performance testing methods have been proposed. For example, in 2023, Zou Jie et al. from Huazhong University of Science and Technology disclosed a dynamic performance testing method and system for a five-axis machine tool in patent CN202310121156.4. The dynamic error of the machine tool was obtained by testing the difference in errors generated by low-speed and high-speed motion of the machine tool; in 2024, Wang Lu Zijun et al. from Kunming University of Science and Technology disclosed a dynamic performance testing device for an industrial robot in patent CN202411587496.7. The structural stiffness of the industrial robot was tested by applying loads to the manipulator in two states: rapid motion and static.

[0004] Research and analysis of existing equipment dynamic performance testing methods revealed that hammering and vibration exciter methods are widely used due to their portability and low cost. However, for dynamic performance testing of large, complex equipment, these methods also exhibit disadvantages such as insufficient excitation, excessive reliance on manual operation techniques, and complex operation. Therefore, the present invention provides an equipment dynamic performance testing method based on a high-thrust vibration table. This method can fully stimulate the dynamic response of the entire equipment, not only obtaining modal parameters such as the equipment's natural frequency and damping ratio, but also verifying the equipment's ability to maintain dynamic performance after vibration loading. Summary of the Invention

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

[0006] The technical solution of the present invention:

[0007] A method for testing the dynamic performance of equipment based on a high-thrust vibration table, the steps are as follows:

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

[0009] The test equipment is installed on the table of a high-thrust vibration table using tooling to simulate the actual installation method. During the test, the test equipment is in a powered-on standby and no-load state, so that the test equipment is in the posture position under actual working conditions, and the posture position is recorded. Acceleration sensors are arranged on the table of the high-thrust vibration table to control the high-thrust vibration table to apply vibration excitation to the test equipment. Acceleration sensors are arranged on the test equipment to monitor the response of the test equipment under vibration excitation.

[0010] Step 2: Conduct a frequency sweep test on the equipment under test;

[0011] Use a high-thrust vibration table to conduct a frequency sweep test on the equipment under test. Set the frequency range, acceleration, and sweep speed of the frequency sweep test. Use an acceleration sensor to collect the vibration excitation signal of the high-thrust vibration table and the response signal of the equipment under test in real time, and draw a spectrum diagram of the vibration response of the equipment under test.

[0012] Step 3: Identification of modal parameters of the equipment under test;

[0013] For the resonant frequencies in the spectrum, the amplitude ratio at each resonant frequency is calculated using formula (1), which is used to describe the significance of the resonance peak of the tested equipment relative to the excitation value of the vibration table.

[0014] (1),

[0015] Where, is the amplitude ratio, is the peak amplitude at the resonant frequency, is the excitation amplitude of the high-thrust vibration table;

[0016] Formula (2) is used to calculate the quality factor at each resonance frequency, which is used to describe the sharpness of the resonance peak of the tested equipment;

[0017] (2),

[0018] Where, is the quality factor, is the resonant frequency, The amplitude drops to The upper and lower frequency limits and The difference is ;

[0019] If the amplitude ratio is satisfied at the same time and quality factor , then the resonant frequency is considered to be the natural frequency of the equipment under test ;

[0020] Formula (3) is used to calculate the natural frequency of the test equipment The corresponding damping ratio ;

[0021] (3);

[0022] Step 4: Conduct vibration loading test on the equipment under test;

[0023] Use a high-thrust vibration table to conduct a long-term vibration loading test on the test equipment at each natural frequency identified in step 3. During the vibration loading, the test equipment must remain in idle operation until the loading time reaches the set value;

[0024] Step 5: Check the vibration response of the equipment under test;

[0025] After the vibration loading test in step 4 is completed, a frequency sweep test is performed on the test equipment again, so that the posture position of the test equipment is the same as that in step 2, and the same frequency sweep test parameters as in step 2 are used; based on the results of the two frequency sweep tests, the frequency offset and amplitude change rate at the resonant frequency of the test equipment are calculated using formula (4) and formula (5) respectively;

[0026] (4)

[0027] Where, is the frequency offset, The resonant frequency of the sweep test in step 2 is: This is the resonant frequency of the frequency sweep test in this step;

[0028] (5)

[0029] Where, is the amplitude change rate, is the peak acceleration at the resonance frequency of the sweep test in step 2, This is the peak acceleration value at the resonance frequency of the frequency sweep test in this step;

[0030] If the calculated result satisfies the frequency offset or amplitude change rate , it is considered that the sweep frequency test results of the test equipment have changed significantly, indicating that there are weak links in the structure of the test equipment, and the test equipment needs to be adjusted and re-tested; if the sweep frequency test results do not change significantly, the inspection process ends.

[0031] A high-thrust vibration table-based equipment dynamic performance testing system includes a vibration generator, an auxiliary support mechanism, an extended table, an equipment fixing mechanism, a test equipment, a vibration monitoring system, and a control and data analysis system; wherein, the vibration generator is located inside the auxiliary support mechanism, and is installed and fixed on the foundation in a center-aligned manner with the auxiliary support mechanism, and both are rigidly connected to the extended table to jointly support the gravity and vibration-induced forces of the extended table; the test equipment is located at the center of the extended table, and is fixed to the extended table by a fixing mechanism; the vibration monitoring system is installed on the extended table, and the control and data analysis system is located on the foundation to the right of the vibration generator and the auxiliary support mechanism, and is used to control vibration excitation and analyze vibration data.

[0032] Beneficial effects of the present invention: The equipment dynamic performance detection method proposed in the present invention is suitable for testing the dynamic performance of large and complex equipment such as machine tools and robots. By using a large-thrust vibration table to perform a sweep frequency test on the test equipment, the dynamic response of the equipment can be fully stimulated. At the same time, by performing a vibration loading test on the test equipment, the ability of the equipment to maintain its dynamic performance during service can be tested, potential weaknesses in the equipment structure can be exposed, and data support can be provided for the improvement and optimization of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a flow chart for equipment dynamic performance testing based on a high-thrust vibration table;

[0034] Figure 2 This is a schematic diagram of the equipment dynamic performance test system based on a high-thrust vibration table;

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

[0036] Figure 4 This is a schematic diagram of the equipment sweep frequency test results based on a high-thrust vibration table.

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

[0038] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and technical solutions.

[0039] Taking the dynamic performance inspection of a CNC machine tool as an example, the embodiments of the present invention are described in detail.

[0040] Step 1: Installation and fixation of the test equipment and arrangement of sensors;

[0041] The CNC machine tool is fixed to the extended table 3 of the high-thrust vibration table through the equipment fixing mechanism 4, and the CNC machine tool is adjusted to a horizontal position; each feed axis of the CNC machine tool is adjusted to a normal working position, the position coordinates of each axis of the CNC machine tool are recorded, and the CNC machine tool is placed in a power-on standby and no-load state; 8 acceleration sensors are arranged on the extended table 3 to collect and control the vibration table to apply vibration excitation to the CNC machine tool; 1 acceleration sensor is arranged on each of the bed, column, worktable, and spindle box of the CNC machine tool to monitor the response signal of the CNC machine tool under vibration excitation.

[0042] Step 2: Conduct a frequency sweep test on the equipment under test;

[0043] A frequency sweep test was conducted on a CNC machine tool using a vibration table. The frequency range of the frequency sweep test was set to 10-100 Hz, the acceleration was 0.2 g, and the sweep speed was 0.5 octave / min. The vibration table's excitation signal and the CNC machine tool's response signal were collected in real time using an acceleration sensor to plot the frequency spectrum of the CNC machine tool's vibration response.

[0044] Step 3: Identification of modal parameters of the equipment under test;

[0045] For the resonant frequency in the spectrum diagram, the amplitude ratio is calculated using formula (1), and the quality factor is calculated using formula (2). After calculation, within the frequency range of the sweep test, 61.562 Hz and 81.727 Hz are considered to be the natural frequencies of the CNC machine tool. The damping ratio corresponding to each natural frequency is calculated using formula (3). The damping ratio corresponding to 61.562 Hz is 0.11, and the damping ratio corresponding to 81.727 Hz is 0.08.

[0046] Step 4: Conduct vibration loading test on the equipment under test;

[0047] A vibration table was used to conduct vibration loading tests on the CNC machine tool at two frequencies of 61.562Hz and 81.727Hz, respectively. The vibration acceleration was set to 0.2g, and the vibration loading duration was 3h at each frequency. While vibration loading, the CNC machine tool operation program was written to make each feed axis of the CNC machine tool feed at high speed, and the feed speed of each axis was set to 5000mm / min.

[0048] Step 5: Check the vibration response of the test equipment.

[0049] After the vibration loading test in step 4 is completed, the frequency sweep test is carried out on the CNC machine tool again. The position coordinates of each feed axis of the CNC machine tool are adjusted to the same as in step 2. The frequency range of the frequency sweep test is set to 10~100Hz, the acceleration is 0.2g, and the frequency sweep speed is 0.5 octave / min. The frequency spectrum of the CNC machine tool after vibration loading is obtained. The frequency offset and amplitude change rate of the two frequency sweep test results of the CNC machine tool are calculated according to formulas (4) and (5). It is found that the amplitude change rate corresponding to the frequency of 81.727Hz is about 34%. The changes in the results of the two frequency sweep tests of the CNC machine tool are relatively obvious, indicating that there are weak links in the structure of the CNC machine tool and the CNC machine tool needs to be adjusted.

[0050] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will appreciate that modifications may be made to the technical solutions described in the aforementioned embodiments, or that some of the technical features may be replaced with equivalents. Such modifications or replacements do not deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for testing the dynamic performance of equipment based on a high-thrust vibration table, characterized by: Here are the steps: Step 1: Installation and fixation of the test equipment and arrangement of sensors; The test equipment is installed on the table of a high-thrust vibration table using tooling to simulate the actual installation method. During the test, the test equipment is in a powered-on standby and no-load state, so that the test equipment is in the posture position under actual working conditions, and the posture position is recorded. Acceleration sensors are arranged on the table of the high-thrust vibration table to control the high-thrust vibration table to apply vibration excitation to the test equipment. Acceleration sensors are arranged on the test equipment to monitor the response of the test equipment under vibration excitation. Step 2: Conduct a frequency sweep test on the equipment under test; Use a high-thrust vibration table to conduct a frequency sweep test on the equipment under test. Set the frequency range, acceleration, and sweep speed of the frequency sweep test. Use an acceleration sensor to collect the vibration excitation signal of the high-thrust vibration table and the response signal of the equipment under test in real time, and draw a spectrum diagram of the vibration response of the equipment under test. Step 3: Identification of modal parameters of the equipment under test; For the resonant frequencies in the spectrum, the amplitude ratio at each resonant frequency is calculated using formula (1), which is used to describe the significance of the resonance peak of the tested equipment relative to the excitation value of the vibration table. （1）， Where, is the amplitude ratio, is the peak amplitude at the resonant frequency, is the excitation amplitude of the high-thrust vibration table; Formula (2) is used to calculate the quality factor at each resonance frequency, which is used to describe the sharpness of the resonance peak of the tested equipment; （2）， Where, is the quality factor, is the resonant frequency, The amplitude drops to The upper and lower frequency limits and The difference is ; If the amplitude ratio is satisfied at the same time and quality factor , then the resonant frequency is considered to be the natural frequency of the equipment under test ; Formula (3) is used to calculate the natural frequency of the test equipment The corresponding damping ratio ; （3）； Step 4: Conduct vibration loading test on the equipment under test; Use a high-thrust vibration table to conduct a long-term vibration loading test on the test equipment at each natural frequency identified in step 3. During the vibration loading, the test equipment must remain in idle operation until the loading time reaches the set value; Step 5: Check the vibration response of the equipment under test; After the vibration loading test in step 4 is completed, a frequency sweep test is performed on the test equipment again, so that the posture position of the test equipment is the same as that in step 2, and the same frequency sweep test parameters as in step 2 are used; based on the results of the two frequency sweep tests, the frequency offset and amplitude change rate at the resonant frequency of the test equipment are calculated using formula (4) and formula (5) respectively; （4） Where, is the frequency offset, The resonant frequency of the sweep test in step 2 is: This is the resonant frequency of the frequency sweep test in this step; （5） Where, is the amplitude change rate, is the peak acceleration at the resonance frequency of the sweep test in step 2, This is the peak acceleration value at the resonance frequency of the frequency sweep test in this step; If the calculated result satisfies the frequency offset or amplitude change rate , it is considered that the sweep frequency test results of the test equipment have changed significantly, indicating that there are weak links in the structure of the test equipment, and the test equipment needs to be adjusted and re-tested; if the sweep frequency test results do not change significantly, the inspection process ends.

2. An equipment dynamic performance inspection system based on a high-thrust vibration table, characterized in that: The equipment dynamic performance testing system includes a vibration generator, an auxiliary support mechanism, an extended table, an equipment fixing mechanism, a test equipment, a vibration monitoring system and a control and data analysis system; wherein, the vibration generator is located inside the auxiliary support mechanism, and is installed and fixed on the foundation in a center-aligned manner with the auxiliary support mechanism, and both are rigidly connected to the extended table to jointly support the gravity and vibration-induced forces of the extended table; the test equipment is located at the center of the extended table, and is fixed to the extended table by the equipment fixing mechanism; the vibration monitoring system is installed on the extended table, and the control and data analysis system is located on the foundation to the right of the vibration generator and the auxiliary support mechanism, and is used to control vibration excitation and analyze vibration data.

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