An integrated vibration and noise testing system and method for actuators
By using a multi-dimensional testing system and signal processing methods, the problems of large size and inconvenient operation of integrated execution unit testing devices in the prior art have been solved, achieving higher robustness and accuracy, and simplifying the operation process.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NINGBO UNIV
- Filing Date
- 2022-12-05
- Publication Date
- 2026-07-17
Smart Images
Figure CN115791045B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of automatic detection, specifically relating to an integrated actuator vibration and noise testing system and method. Background Technology
[0002] Integrated actuators, composed of a motor, driver, and reducer, offer advantages such as good reconfigurability, high redundancy, convenient assembly, flexibility, and ease of maintenance. They also boast superior performance, short development cycles, and low costs, making integrated actuator technology a highly favored field in space robotics, next-generation collaborative robots, and high-end CNC equipment. Currently, integrated actuators are widely used in various sectors of industrial production and social life, especially in industrial production. Improving the safety and reliability of equipment systems has become an urgent task, and timely and accurate detection of potential or existing integrated actuator faults through testing is a crucial step in ensuring their safe operation. Integrated actuators generate noise and vibration during operation, with variations in vibration and frequency under different operating conditions. This provides a practical basis for research on integrated actuator testing methods based on noise and vibration analysis.
[0003] Currently, integrated actuator testing devices are bulky and inconvenient to operate. Most testing methods only apply vibration as the sole criterion for evaluating the quality of integrated actuators. Furthermore, they require the establishment of accurate mathematical models, effective state or parameter estimations, and appropriate statistical decision-making methods, making the procedures cumbersome and inconvenient to use. Summary of the Invention
[0004] To overcome the shortcomings of existing technologies, this invention provides an integrated vibration and noise testing system and method for actuators. This device and method exhibit high robustness and accuracy, perform multi-dimensional testing, yield accurate results, and are convenient and quick to implement.
[0005] An integrated actuator vibration and noise testing system includes a signal processing and judgment module, a data acquisition module, and a test bench, with the integrated actuator arranged on the test bench.
[0006] The signal processing and judgment module includes a processing and judgment algorithm module and a host computer. The processing and judgment algorithm runs on the host computer and is used for signal processing and judgment.
[0007] The data acquisition module includes a noise acquisition module and a vibration acquisition module. The vibration acquisition module includes a non-contact vibration sensor for measuring the vibration velocity of the integrated actuator and a contact vibration sensor for measuring the vibration acceleration of the integrated actuator. The signal output terminals of the noise acquisition module and the non-contact vibration sensor are connected to the host computer for communication.
[0008] The early warning module is used to receive signals from the signal processing and judgment module and to issue alarms for abnormal data processed by the signal processing and judgment module.
[0009] A vibration and noise testing method for an integrated actuator includes the following:
[0010] S1. System initialization: This includes initializing and checking all hardware devices, signal processing and recognition modules, and data acquisition modules to ensure that no abnormalities occur and to make necessary preparations for the operation of the system.
[0011] S2. Signal Acquisition: A non-contact vibration sensor and microphone are mounted on a six-axis bracket. The non-contact vibration sensor faces the integrated actuator to measure the radial vibration displacement of the integrated actuator's output shaft. The measured signal is transmitted to the host computer via a data acquisition card for signal processing. The microphone is also positioned facing the integrated actuator to measure the sound of its operation. The measured signal is transmitted to the host computer via a data acquisition card for signal processing. A contact vibration sensor is attached to the integrated actuator to collect the acceleration signal of its vibration. The measured signal is transmitted to the host computer via a data acquisition card for signal processing.
[0012] S3. Signal Processing: including wavelet denoising, variational mode decomposition feature extraction, and support vector machine judgment;
[0013] S4. Warning: If the integrated execution unit signal is deemed unqualified, an alarm will be triggered.
[0014] The advantages of this invention compared to the prior art are:
[0015] Traditional integrated execution unit (APU) testing methods mostly only use vibration as the sole dimension for evaluating APU quality. This invention uses both sound and vibration as dimensions for comprehensive judgment. Sound is collected using a microphone to capture mid-to-high frequency signals (1000Hz-8000Hz), while vibration is collected using contact and non-contact vibration sensors to capture low frequency signals (0-1000Hz). Sound and vibration complement each other, improving robustness and accuracy compared to traditional testing methods.
[0016] Traditional integrated actuator testing methods only measure vibration on the surface of the integrated actuator housing. This invention uses a non-contact vibration sensor to measure the vibration displacement on the output shaft of the integrated actuator and a contact vibration sensor to measure the vibration acceleration on the housing of the integrated actuator, resulting in more accurate results.
[0017] Traditional integrated unit test systems require accurate mathematical models, effective state or parameter estimations, and appropriate statistical decision-making methods. These prerequisites impose certain limitations on traditional integrated unit test systems. This invention employs variational mode decomposition and support vector machines to simplify, facilitate, and expedite the testing process.
[0018] Traditional integrated execution unit testing devices are bulky and inconvenient to operate. This invention provides a test bench whose position can be adjusted according to the testing environment, making it more flexible and easier to use.
[0019] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments: Attached Figure Description
[0020] Figure 1 This is a schematic diagram of the vibration and noise testing process for the integrated actuator of the present invention;
[0021] Figure 2 This is a schematic diagram of the integrated actuator vibration and noise testing system of the present invention;
[0022] Figure 3 This is a schematic diagram of the microphone layout;
[0023] Figure 4 This is a schematic diagram of the arrangement of a contact vibration sensor;
[0024] Figure 5 This is a flowchart of the signal processing based on variational mode decomposition and support vector machine in the embodiment;
[0025] Figure 6 This is a system interface diagram for an example.
[0026] The components include: 1. Contact vibration sensor, 2. Non-contact vibration sensor, 3. Microphone, 4. Integrated actuator, 5. Six-axis support, and 6. Test bench. Detailed Implementation
[0027] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. Unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning understood by those skilled in the art.
[0028] Example 1, such as Figures 1-2 As shown, an integrated actuator vibration and noise testing system includes a signal processing and judgment module, a data acquisition module, and a test bench 6. The integrated actuator is arranged on the test bench 6.
[0029] The signal processing and judgment module includes a processing and judgment algorithm module and a host computer. The processing and judgment algorithm runs on the host computer and is used for signal processing and judgment.
[0030] The data acquisition module includes a noise acquisition module and a vibration acquisition module. The vibration acquisition module includes a non-contact vibration sensor for measuring the vibration velocity of the integrated actuator 4 and a contact vibration sensor for measuring the vibration acceleration of the integrated actuator 4. The signal output terminals of the noise acquisition module and the non-contact vibration sensor are connected to the host computer for communication.
[0031] The early warning module is used to receive signals from the signal processing and judgment module and to issue alarms for abnormal data processed by the signal processing and judgment module.
[0032] The signal processing and judgment module receives signals from the data acquisition module, processes the data acquired by the data acquisition module using the software system, and issues an alarm upon detecting data anomalies. Figure 6 As shown.
[0033] Example 2, as follows Figure 2 As shown, the noise acquisition module includes a microphone, a preamplifier, a constant current adapter, a DC power supply, and a data acquisition card. The microphone is connected to the preamplifier, the constant current adapter powers both the preamplifier and the contact vibration sensor, the data acquisition card is powered by the DC power supply and connected to a host computer, and the signal output terminals of the microphone and the contact vibration sensor are connected to the signal input terminals of the host computer. Optionally, an AWA14423 microphone is used, positioned directly facing the integrated actuator to measure the sound of the integrated actuator's operation. The measured signal is transmitted to the host computer via the data acquisition card for signal processing. An AWA14604(E) preamplifier, an ACE5002 constant current adapter, and a NI usb-6363 data acquisition card are used. The microphone is used to acquire mid-to-high frequency signals (1000Hz-8000Hz) for sound, while a contact vibration sensor and a non-contact vibration sensor are used to acquire low-frequency signals (0-1000Hz). Sound and vibration complement each other, improving robustness and accuracy compared to traditional testing methods.
[0034] Example 3, such as Figure 3As shown: The microphone 3 is arranged with a hemispherical measurement surface, a test radius r of 0.4m, and four measurement points (measurement point 1, measurement point 2, measurement point 3, and measurement point 4), configured in four mutually perpendicular directions (front, back, left, and right) around the integrated execution unit 4. The height of the measurement points is 0.25m, and the center of the test radius is the intersection of the perpendicular line passing through the center of the integrated execution unit and the reflecting ground. In this embodiment 3, the integrated execution unit is installed in a free-suspension manner, that is, the integrated execution unit 4 is mounted on a sponge pad. The microphone 3 is used to collect the sound pressure level of the operating noise of the integrated execution unit. Four microphones 3 are used to measure the noise of the integrated execution unit 4 during operation. The microphones 3 are configured in four mutually perpendicular directions (front, back, left, and right) around the integrated execution unit 4. The preamplifier is used to amplify the level signal collected by the microphones. The constant current adapter supplies power to the microphones 3. The microphones 3 are mounted on a six-axis support 5, and the six-axis support 6 is used to adjust the position of the microphones 3. The NI USB-6363 data acquisition card is used to collect the level signal amplified by the preamplifier. A circular guide rail supports the six-axis bracket 5, which can slide on the circular guide rail for easy measurement by the user. The rest of Embodiment 1 or Embodiment 2 is the same. The six-axis bracket is used to fix the non-contact vibration sensor and microphone; the position can be adjusted according to the testing environment, making it more flexible and easier to use.
[0035] Example 4, such as Figure 4 As shown, this embodiment uses a contact vibration sensor 1 to measure the acceleration of vibration during operation of the integrated actuator 4. The measuring points are arranged as follows. Figure 4 As shown (measuring points 1, 2, 3, 4, 5, and 6), two measuring points (measuring points 1 and 6) are used to measure the axial vibration acceleration of the integrated actuator 4, and four measuring points (measuring points 2, 3, 4, and 5) are used to measure the radial vibration acceleration of the integrated actuator 4. The data acquisition card is used to acquire the acceleration signals output by the contact vibration sensor. The non-contact vibration sensor 2 is mounted on a six-axis bracket 5, which has the function of adjusting the six-axis direction, so as to facilitate the adjustment of the measuring point position and make the measuring point located on the output axis of the integrated actuator 4.
[0036] Example 5, as Figure 5 and Figure 6 As shown, a vibration and noise testing method for an integrated actuator includes the following:
[0037] S1. System initialization: This includes initializing and checking all hardware devices, signal processing and recognition modules, and data acquisition modules to ensure that no abnormalities occur and to make necessary preparations for the operation of the system.
[0038] S2. Signal Acquisition: A non-contact vibration sensor and microphone are mounted on a six-axis bracket. The non-contact vibration sensor faces the integrated actuator to measure the radial vibration displacement of the integrated actuator's output shaft. The measured signal is transmitted to the host computer via a data acquisition card for signal processing. The microphone is also positioned facing the integrated actuator to measure the sound of its operation. The measured signal is transmitted to the host computer via a data acquisition card for signal processing. A contact vibration sensor is attached to the integrated actuator to collect the acceleration signal of its vibration. The measured signal is transmitted to the host computer via a data acquisition card for signal processing.
[0039] S3. Signal Processing: including wavelet denoising, variational mode decomposition (VMD) feature extraction, and support vector machine (SVM) decision-making;
[0040] S4. Warning: If the integrated execution unit signal is determined to be unqualified, a warning will be issued;
[0041] The software system includes VMD feature extraction, SVM judgment, and early warning.
[0042] Furthermore, in step S3 of signal processing, wavelet denoising serves the purpose of removing random noise from the integrated execution unit signal acquired against a strong noise background, thus obtaining a relatively pure sound and vibration signal. The principle of wavelet denoising is to decompose the noisy signal into a low-frequency component l, where l = (l1, l2, ..., l...). n ), and the high-frequency component (wavelet coefficients) h, h = (h1, h2, ..., h n ), where n is the data length. It is generally believed that smaller wavelet coefficients are caused by noise; therefore, a zero-setting threshold m is set. If |h n If | < m, set it to zero, and keep the rest.
[0043] The main function of variational mode decomposition (VMD) is to decompose the original signal into several IMF components. The number of components varies depending on the sampling rate, typically ranging from 4 to 8. Each IMF is a frequency-modulated (FM) and amplitude-modulated (AM) signal with limited bandwidth. Assuming the input signal consists of K IMF components, then for each IMF component signal u... k (t) all have:
[0044]
[0045] In the formula, A k (t) represents u k The instantaneous amplitude of (t), and satisfying A k (t)≥0; Indicate uk The instantaneous phase of (t), then u k The instantaneous frequency of (t) can be expressed as:
[0046]
[0047] In the formula, ω k (t)≥0
[0048] Then, the frequency centroid and frequency energy are extracted as features for each IMF component.
[0049] Frequency centroid:
[0050]
[0051] Where X(ω) represents the Fourier transform of the audio or vibration frame at frequency ω, the numerator is the energy of the audio or vibration frame at ω, the denominator is the average energy of the audio or vibration frame as a whole, and their ratio is called the frequency centroid.
[0052] Frequency energy:
[0053]
[0054] Where X(ω) represents the Fourier transform of the audio frame or vibration frame at frequency ω, ω0 is half of the sampling frequency, and finally a support vector machine classifier is used to classify the features to obtain a complete test system. The classifier divides the integrated execution unit into two categories: Class A (qualified) and Class B (unqualified).
[0055] The present invention has been disclosed above with reference to preferred embodiments, but it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed structure and technical content to create equivalent embodiments without departing from the scope of the present invention, and all such modifications or alterations shall still fall within the scope of the present invention.
Claims
1. A method for testing vibration and noise of an integrated actuator, characterized in that: The system described in this method includes a signal processing and judgment module, a data acquisition module, and a test bench, with the integrated execution unit arranged on the test bench. The signal processing and judgment module includes a processing and judgment algorithm module and a host computer. The processing and judgment algorithm runs on the host computer and is used for signal processing and judgment. The data acquisition module includes a noise acquisition module and a vibration acquisition module. The vibration acquisition module includes a non-contact vibration sensor for measuring the vibration velocity of the integrated actuator and a contact vibration sensor for measuring the vibration acceleration of the integrated actuator. The noise acquisition module and the signal output terminal of the non-contact vibration sensor are connected to the host computer for communication. The early warning module is used to receive signals from the signal processing and judgment module and to issue an alarm for abnormal data processed by the signal processing and judgment module. The method includes the following: S1. System initialization: This includes initializing and checking all hardware devices, signal processing and recognition modules, and data acquisition modules to ensure that no abnormalities occur and to make necessary preparations for the operation of the system. S2. Signal Acquisition: A non-contact vibration sensor and microphone are mounted on a six-axis bracket. The non-contact vibration sensor faces the integrated actuator and measures the radial vibration displacement of the output shaft of the integrated actuator. The measured 0-1000Hz low-frequency signal is transmitted to the host computer through a data acquisition card for signal processing. The noise acquisition module includes a microphone. The microphone is faced the integrated actuator to measure the sound of the integrated actuator during operation. The measured 1000-8000Hz high-frequency signal is transmitted to the host computer through a data acquisition card. The host computer performs signal processing; a contact vibration sensor is attached to the integrated actuator to collect the acceleration signal of the integrated actuator's vibration, and the measured 0-1000Hz low-frequency signal is transmitted to the host computer through a data acquisition card for signal processing. S3. Signal Processing: including wavelet denoising, variational mode decomposition feature extraction, and support vector machine judgment; Variational mode decomposition (VMD) decomposes the original signal into several IMF components. The number of components varies with the sampling rate. Each IMF is a bandwidth-limited frequency-modulated amplitude-modulated signal. Assuming the input signal consists of K IMF components, then for each IMF component signal... All of them are: In the formula, express The instantaneous amplitude, and satisfying ; express The instantaneous phase, then The instantaneous frequency can be expressed as: In the formula, Then, extract the frequency centroid and frequency energy as features for each instantaneous frequency; S4. Warning: If the integrated execution unit signal is deemed unqualified, an alarm will be triggered.
2. The vibration and noise testing method for an integrated actuator according to claim 1, characterized in that: The centroid of the frequency: in, Indicates frequency The Fourier transform of the audio or vibration frame at a point, where the numerator is the audio or vibration frame at that point. The energy at a given point, with the denominator being the average energy of the entire audio frame or vibration frame, and their ratio is called the frequency centroid. The frequency energy: in, Indicates frequency Fourier transform of audio frames or vibration frames at a given point. Half the sampling frequency, Finally, a support vector machine classifier is used to classify the features. The classifier divides the integrated execution unit into two categories: qualified and unqualified.
3. The vibration and noise testing method for an integrated actuator according to claim 1, characterized in that: The noise acquisition module also includes a preamplifier, a constant current adapter, a DC power supply, and a data acquisition card; the microphone is connected to the preamplifier, the constant current adapter supplies power to the preamplifier and the contact vibration sensor respectively, the data acquisition card is powered by the DC power supply, the data acquisition card is connected to the host computer, and the signal output terminals of the microphone and the contact vibration sensor are connected to the signal input terminals of the host computer.