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- 摘要
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Automatic signal quality check and equipment condition surveillance based on trivalent logic diagnosis theory
摘要： In the field of fault diagnosis, inadequate signals measured for equipment condition monitoring may cause incorrect diagnostic results and reduce the accuracy and reliability of the equipment diagnosis system. This paper proposes a method of signal quality check and equipment condition surveillance based on trivalent logic theory, signal histogram analysis and principal component analysis (PCA), in order to automatically evaluate the quality of measured signals to ensure that the signals are real and valid for the condition diagnosis of equipment, and automatically judge the equipment state for condition surveillance. The novelty of this paper are summarized as: (1) Trivalent logic has been expanded appropriately into the trivalent logic diagnosis theory, so that it can be applied to verify the signal quality in the acquisition process for fault diagnosis and equipment condition surveillance; (2) In order to directly and effectively extract features of a signal following any probability density distribution, the histograms of the signal measured for equipment condition diagnosis is used to substitute time domain symptom parameters which have been generally used in equipment diagnosis technology; (3) PCA is used to integrate the histograms to realize signal quality check and equipment condition surveillance on the basis of the trivalent logic diagnosis theory. By the method proposed in this paper, the moment when the signal for equipment condition diagnosis is relatively stable can be found, and the unfavorable signal can be avoided for ensuring the accuracy and reliability of the equipment condition diagnosis. Simulation signals and real signals measured in various conditions from a blower are respectively used to verify the effectiveness of the proposed method.
关键词： Condition monitoring,Fault diagnosis,Measurement errors,Histograms,Vibration measurement
更新于2025-09-23 15:23:52
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A Flexible Mode Electrolytic Capacitor-Free LED Driver with High-Efficiency Over a Wide Range of Input Voltage
摘要： This paper demonstrates the use of low-cost off-the-shelf (OTS) microelectromechanical system (MEMS) technology to perform vibration-based in situ monitoring, diagnostics, and characterization of a MEMS microball bearing supported radial air turbine platform. A multimodal software suite for platform automation and sensor monitoring is demonstrated using a three-level heuristic software suite and sensor network. The vibration diagnostic methods used in the platform have applications in rotary microsystems for the early detection of failure, fault diagnosis, and integrated diagnostic systems for feedback-based optimization to increase device performance, reliability, and operational lifetimes. The studied rotary microdevice used a dual OTS accelerometer configuration for dual range parallel redundant vibration analysis. The sensor suite has been used to monitor and detect multiple operational parameters measured optimally in time or frequency domains such as rotor instability, imbalance, wobble, and system resonance. This paper will lay the framework for active diagnostics in future MEMS devices through integrated systems.
关键词： rotating machine stability,Non-destructive,vibration measurement,measurement,rotating machine
更新于2025-09-23 15:19:57
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Evaluating the Incident Energy of Arcs In Photovoltaic DC Systems: Comparison Between Calculated and Experimental Data
摘要： This paper demonstrates the use of low-cost off-the-shelf (OTS) microelectromechanical system (MEMS) technology to perform vibration-based in situ monitoring, diagnostics, and characterization of a MEMS microball bearing supported radial air turbine platform. A multimodal software suite for platform automation and sensor monitoring is demonstrated using a three-level heuristic software suite and sensor network. The vibration diagnostic methods used in the platform have applications in rotary microsystems for the early detection of failure, fault diagnosis, and integrated diagnostic systems for feedback-based optimization to increase device performance, reliability, and operational lifetimes. The studied rotary microdevice used a dual OTS accelerometer configuration for dual range parallel redundant vibration analysis. The sensor suite has been used to monitor and detect multiple operational parameters measured optimally in time or frequency domains such as rotor instability, imbalance, wobble, and system resonance. This paper will lay the framework for active diagnostics in future MEMS devices through integrated systems.
关键词： rotating machine stability,Non-destructive,vibration measurement,measurement,rotating machine
更新于2025-09-23 15:19:57
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Heterodyne interferometry at ultra-high frequencies with frequency-offset-locked semiconductor lasers
摘要： Modern broadband telecommunications require microelectromechanical filters which mechanically vibrate at ultra-high frequencies up to several gigahertz. Heterodyne interferometers, so-called laser-Doppler vibrometers (LDVs), provide a sensitive and contactless measurement technique for vibrations in such filters, but are limited in GHz heterodyning by the efficiency drop of acousto-optic frequency shifting. Heterodyning by frequency-offset locking of two lasers in an optoelectronic phase-locked loop (OPLL) overcomes this limitation. This is demonstrated with our LDV setup with heterodyning up to 1.4 GHz via offset locking of two semiconductor lasers at visible wavelength. The experiments show a vibration-amplitude resolution of less than 1 pm Hz for frequencies higher than 50 MHz up to 700 MHz. The bandwidth is only per limited by our photodetectors. This amplitude resolution already qualifies our LDV for vibration measurement of microelectromechanical filters at ultra-high frequencies. We present a comprehensive model for the vibration-amplitude resolution of a LDV with this technique including the laser linewidths, the OPLL transfer function, and interferometer delays. The experiments with our LDV validate the model predictions from numerical simulations. Finally, we discuss the collapse of the heterodyne carrier at vanishing mutual coherence due to interferometer delays, the transition to shot-noise-limited detection, and provide design recommendations.
关键词： MEMS testing,Vibration measurement,Optical phase-locked loop,Heterodyne interferometry
更新于2025-09-23 15:19:57
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Low-frame-rate single camera system for 3D full-field high-frequency vibration measurements
摘要： A single-camera stereo-digital image correlation (stereo-DIC) system to obtain 3D full-field vibration measurements is proposed. The optical setup is composed of two planar mirrors and a single low frame rate camera, thus resulting in a compact and low-cost equipment. The two mirrors are used to create pseudo-stereo images of a target surface on the camera sensor, which are then correlated by using stereo-DIC. The image acquisition process is carried out at low frame rates and the Nyquist-Shannon frequency limitation is overcome by adopting a down-sampling approach under the hypothesis that the vibration signal is characterized by a single known frequency component. The developed pseudo-stereo DIC system allows to obtain 3D full-field vibration measurements in a frequency range up to 4 kHz even with an available frame rate (at full resolution) of 178 fps. The effectiveness of the described approach has been verified by performing vibration measurements on a cantilever plate and a turbine blade.
关键词： Single low-speed camera,Vibration measurement,Down-sampling approach,Digital image correlation
更新于2025-09-19 17:15:36
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[IEEE 2019 International Conference on Electrical Engineering and Informatics (ICEEI) - Bandung, Indonesia (2019.7.9-2019.7.10)] 2019 International Conference on Electrical Engineering and Informatics (ICEEI) - Determination of Maximum Grid-Connected Photovoltaic Penetration Level Based on Unit Commitment Solution
摘要： This paper demonstrates the use of low-cost off-the-shelf (OTS) microelectromechanical system (MEMS) technology to perform vibration-based in situ monitoring, diagnostics, and characterization of a MEMS microball bearing supported radial air turbine platform. A multimodal software suite for platform automation and sensor monitoring is demonstrated using a three-level heuristic software suite and sensor network. The vibration diagnostic methods used in the platform have applications in rotary microsystems for the early detection of failure, fault diagnosis, and integrated diagnostic systems for feedback-based optimization to increase device performance, reliability, and operational lifetimes. The studied rotary microdevice used a dual OTS accelerometer configuration for dual range parallel redundant vibration analysis. The sensor suite has been used to monitor and detect multiple operational parameters measured optimally in time or frequency domains such as rotor instability, imbalance, wobble, and system resonance. This paper will lay the framework for active diagnostics in future MEMS devices through integrated systems.
关键词： rotating machine stability,Non-destructive,rotating machine measurement,vibration measurement
更新于2025-09-19 17:13:59
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Laser dot projection videogrammetry for vibration measurement and control of a piezoelectric flexible cantilever plate
摘要： A novel full-field non-contact vibration measurement method is investigated for a piezoelectric flexible cantilever plate, using laser dot-projection videogrammetry. Several laser dots are projected as marks for visual system. The three-dimensional coordinates of each mark are monitored by a binocular stereo vision system, composed of two cameras. After image processing, the vibration signal of the first bending mode is obtained. For the first torsional mode, two laser displacement sensors are utilized to detect the vibration. To suppress the residual vibration quickly, an adaptive nonlinear controller and a fuzzy tuning nonlinear controller are designed and adopted. To verify the investigated measurement and control methods, experiments are conducted by using a piezoelectric flexible cantilever plate experimental platform. The experimental results demonstrate that the investigated laser dot projection measurement method is effective for first bending vibration detection. Furthermore, compared with PD control, the adopted nonlinear algorithms have better damping performance, especially for small amplitude residual vibration.
关键词： Vibration measurement,Nonlinear control algorithm,Piezoelectric flexible plate,Laser dot projection,Videogrammetry
更新于2025-09-19 17:13:59
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Vibration Measurement Based on the Local Maximum Detection Algorithm for Laser Self-Mixing Interferometry
摘要： A novel laser self-mixing interferometry vibration measurement algorithm based on the local maximum detection technique is proposed, that can reconstruct micro vibrations rapidly and easily. In this article, the principles of the local maximum detection algorithm are analyzed in detail, and the process of solving the window function is emphasized. The major advantage of the method is that it does not involve any complicated calculations and removes the need for optical/electromechanical components. The validity of the presented method is confirmed by means of simulated signals and demonstrated via several experiments for harmonic and aleatory motion.
关键词： local maximum detection,self-mixing interferometry,vibration measurement
更新于2025-09-19 17:13:59
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Vibration measurement based on multiple Hilbert transform for self-mixing interferometry
摘要： In order to reconstruct the micro-vibration quickly and easily, a novel phase unwrapping algorithm based on multiple Hilbert transform is proposed. Hilbert transform is performed once and three times for self-mixing fringes on different inclined directions, then the unwrapped phase is obtained and the micro-vibration can be reconstructed under weak or even moderate feedback. In this paper, the validity of the proposed algorithm is confirmed by means of simulated signals and demonstrated by several experimental measurements for both harmonic and aleatory target vibration.
关键词： Vibration measurement,Multiple Hilbert transform,Self-mixing interferometry,Phase unwrapping
更新于2025-09-04 15:30:14
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Dynamic Characteristics of Satellite Solar Arrays under the Deployment Shock in Orbit
摘要： Understanding the dynamic characteristics of solar arrays is important for satellite structural design and attitude control design. Considerable theoretical researches have been carried out towards this problem, but they have not been supported by actual orbit data from outer space yet. In this paper, the on-orbit vibration characteristic data of solar arrays under the deployment shock are measured by using vibration measurement apparatuses based on structural strain. With these valuable experimental data, more eigenfrequencies of the solar arrays in the microgravity environment are obtained, and the prediction that the vibration of solar arrays will have larger amplitude and longer decay time under vacuum conditions is veri?ed. Moreover, by comparing the eigenfrequency of main vibration under the space condition with that under the ground condition, the accurate value of the system damping ratio is gained, which has an important guideline signi?cant for the structural design of solar arrays.
关键词： solar arrays,deployment shock,on-orbit data,vibration measurement,dynamic characteristics
更新于2025-09-04 15:30:14