- 标题
- 摘要
- 关键词
- 实验方案
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Parametric Study and Optimization of Linear and Nonlinear Vibration Absorbers Combined with Piezoelectric Energy Harvester
摘要： In this work, a harmonically excited generalized two degree of freedom non-linear system is used to manifest the functions of both the vibration absorber and energy harvester simultaneously. The generalized system has been reduced to a linear primary system with linear/nonlinear absorber and harvester or nonlinear primary system with linear/nonlinear absorber and harvester. Multi-harmonic balance method (MHBM) along with arc length continuation is used for generating frequency response plots for different absorber and energy harvester system parameters with constant primary system parameters and excitation amplitude. The frequency response plots show multiple branches of stable periodic solutions and jump at certain frequency ranges for systems with nonlinearity. The absorber and energy harvester parameters are optimized using an optimization procedure based on genetic algorithm in combination with response surface methodology. The method is validated with analytical solutions available in the literature for a linear primary system with linear absorber and harvester and nonlinear primary system with nonlinear absorber alone. This study demonstrates that the proposed optimization framework along with MHBM is suitable for generating the optimal frequency response for multifunctional energy harvesting systems or systems with nonlinear absorber. The frequency response plots with optimal parameter values reiterates the fact that the absorber system with nonlinear element perform better compared to its linear counterpart over a wider band of frequencies. The study also reports the comparison of the performance of a combined nonlinear absorber harvester system with that of a nonlinear energy sink (NES) absorber harvester system.
关键词： vibration absorber,multi-harmonic balancing,energy harvesting,optimization,response surface method,genetic algorithm
更新于2025-09-23 15:23:52
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[IEEE 2018 China International SAR Symposium (CISS) - Shanghai (2018.10.10-2018.10.12)] 2018 China International SAR Symposium (CISS) - A High Frequency Vibration Compensation Approach in Terahertz SAR Based on Wavelet Multi-Resolution Analysis
摘要： The use of terahertz wave in SAR imaging can solve the difficulties of frame rate and detection of slow moving targets in conventional SAR imaging. The most important difference between terahertz SAR (THz-SAR) and conventional SAR is the treatment on motion compensation. For reason that the wavelength of terahertz SAR is much shorter than that of conventional microwave SAR, the tiny vibration of SAR platform will blur SAR images, especially high frequency components. The high frequency vibration will result in paired echoes in SAR imaging, which can't be focused with traditional SAR imaging algorithms. Thus the vibration parameters can't be estimated precisely enough to construct the reference function to compensate the sinusoidal modulation phase. So we first get focused paired echoes in terahertz SAR imaging through Doppler keystone transform (DKT), then we propose a frequency estimation method based on wavelet multi-resolution analysis, along with parametric space projection method, to complete the high frequency vibration estimation of terahertz SAR. At last, the numerical tests using the point target echoes validate the proposed method.
关键词： synthetic aperture radar,high frequency vibration error,Terahertz,wavelet multi-resolution analysis,vibration estimation
更新于2025-09-23 15:22:29
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Size-Dependent Buckling and Vibrations of Piezoelectric Nanobeam with Finite Element Method
摘要： In the present paper, a finite element method is used to study the vibrations and buckling of a piezoelectric nanobeam. The beam theory used here is Bernoulli–Euler model. In order to achieve the goal, first, the governing equations of the piezoelectric nanobeam were obtained via the Hamilton principle, based on the higher-order theory such as modified couple stress. The shape functions were embedded in these equations, and the matrix form of the equations was obtained. In other words, the governing equations were discretized by the finite element method. By calculating the matrix form of equations, mass matrices, mechanical stiffness and electrical stiffness of the beam were obtained. It should be noted that when calculating stiffness matrices, first, the definition of a new element must be added to the effects of the electric field in the elements of the beam, and the effects of the gradient of strain should be added in the form of non-classical matrix to the stiffness matrix. With the aid of these critical load matrices, the buckling force and voltage and the natural frequency of the piezoelectric nanobeam have been calculated. Numerical results show that this method can involve the size effects.
关键词： Size effect,Piezoelectric,Buckling voltage,Couple stress theory,Free vibration,Buckling load
更新于2025-09-23 15:22:29
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Modes of vibration, stability and internal resonances on non-linear piezoelectric small-scale beams
摘要： This paper presents a non-linear piezoelectric size-dependent Rayleigh’s beam model, based on modified couple stress theory, a non-classical continuum theory that is sensitive to the size effect. Hamilton principle is employed to determine the partial differential governing equations and the boundary conditions. Free periodic vibrations are studied, with the goal of investigating the modes of vibration of piezoelectric small-scale beams in the non-linear regime, a study that appears to be lacking in the literature. The method of multiple scales and a shooting method are applied to solve the equations of motion; the stability of the solutions computed by the shooting method is investigated. A hinged-hinged beam is chosen as an example to delineate the non-linear size dependent free vibration behaviour. For the first time in this specific problem, secondary branches due to bifurcations are found. An important novelty of the work is that these secondary branches are determined using the shooting method, which does not suffer from the drawbacks of popular alternatives, as perturbation methods and the method of harmonic balance.
关键词： Piezoelectric,Modified couple stress,Non-linear modes of vibration,Small scale beams
更新于2025-09-23 15:22:29
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[IEEE 2018 Conference on Design and Architectures for Signal and Image Processing (DASIP) - Porto, Portugal (2018.10.10-2018.10.12)] 2018 Conference on Design and Architectures for Signal and Image Processing (DASIP) - Implementation of a Real-Time Image-Based Vibration Detection and Adaptive Filtering on an FPGA
摘要： In this paper, we propose and implement a field-programmable gate array (FPGA) system which extracts a vibration component of a desired frequency band from moving images in real-time, aiming at application to image-based vibration suppression such as microsurgery assistance systems. The technical challenges to this end are two-fold: fast and robust detection of vibration components in given moving images and zero-phase band-pass filtering for a desired frequency band. For the former, we employ a statistical approach using dense optical flow to derive frequency components, and design a custom optical flow computing hardware with the Lucas-Kanade (LK) method. For the latter, we implement a sort of adaptive band-pass filters called a bandlimited multiple Fourier linear combiner (BMFLC), which can recompose input signals as a mixture of sinusoidal signals with multiple frequencies in a band with no phase delay. Both designs are implemented in a deeply pipelined manner on a Xilinx Kintex-7 XC325T FPGA, without using any external memories. Empirical experiments reveal that the proposed system extracts a vibration component of high-frequency tremors in hand motions, while intentional low-frequency motions are successfully filtered out. The system processes VGA moving images at 60 fps, with a delay of less than 1 us for the BMFLC, suggesting effectiveness of the deep pipelined architecture.
关键词： FPGA,optical flow,real-time image processing,adaptive filtering,vibration detection
更新于2025-09-23 15:22:29
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Fuzzy neural network vibration control on a piezoelectric flexible hinged plate using stereo vision detection
摘要： Vibration control on a two-connected piezoelectric flexible hinged plate is investigated, using a fuzzy neural network algorithm based on binocular vision measurement. As for vision sensing, a method to acquire vibration signals of the low frequency bending and torsional mode is investigated. To damp out the residual vibration quickly, the fuzzy neural network is applied to ensure the stability and control effect adaptively. To verify the stereo vision measurement method and the applied controller, an experimental setup of the piezoelectric flexible hinged plate with a binocular stereo vision is constructed. Experiments are conducted by using the binocular stereo vision measurement system and the adopted controller. The experimental results demonstrate the feasibility of the visual measurement method. Furthermore, the designed fuzzy neural network can attenuate the bending and torsional vibrations quickly, in comparison with proportional and derivative control, particularly for the small-level residual vibration.
关键词： Piezoelectric flexible hinged plate,binocular vision measurement,experiments,vibration control,fuzzy neural network algorithm
更新于2025-09-23 15:22:29
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Mass measurement of grasped object with tweezers employing bimorph piezoelectric actuators
摘要： This paper deals with tweezers for a mass detection during micromanipulation. It measures 52 mm×30 mm×10 mm and weighs 37 g. Each ?nger consists of a bimorph piezoelectric actuator with a stainless steel tip. One of the tweezers working as a vibrator was oscillated at its resonance frequency, and another working as a grasper opened and closed the gap between the tips of the bimorph piezoelectric actuators. The simulation model that represents the contact of two beams and a lumped mass as springs was described. The resonance frequency was increased when the tweezers grasped an object. The relationship between the mass of the object and frequency was obtained experimentally. Because the charge generated by the piezoelectric effect also affected the resonance frequency, the frequency change in the experiments was smaller than that in the simulation.
关键词： resonance frequency,mass evaluation,cantilever,Piezoelectric actuator,vibration
更新于2025-09-23 15:22:29
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[IEEE 2018 3rd International Conference On Internet of Things: Smart Innovation and Usages (IoT-SIU) - Bhimtal (2018.2.23-2018.2.24)] 2018 3rd International Conference On Internet of Things: Smart Innovation and Usages (IoT-SIU) - Fiber Bragg Grating basedLandslide Early Warning System
摘要： Landslides are natural hazards which are known to cause loss of life and infrastructural damage. Landslide Early Warning System (LEWS) is intended to predict the occurrence of the landslide which provides ample time to initiate necessary protective measures. In the present study, a Fiber Bragg Grating (FBG) sensor based vibration sensor which can acquire the seismic vibrations is proposed as an LEWS. The proposed Fiber Bragg Grating Vibration Sensor (FBGVS) works on a specially designed cantilever structure, through which the seismic vibrations can be obtained in the form of strain variations on the cantilever. The strain variations over the cantilever will be acquired by the FBG sensor bonded over it. The cantilever is specially designed such that the strain sensitivity of the FBGVS is enhanced, by the appending of torsional strain along with the axial strain. Experimental trials have been carried out which prove the efficacy of the FBGVS to acquire the seismic vibrations. FBGVS acts as the sensing element for an IoT system to ensure the landslide warning signal is transmitted to all remote locations, effectively making an efficient LEWS.
关键词： Fiber Bragg grating sensor,Landslide Early Warning System,Fiber Bragg Grating Vibration Sensor
更新于2025-09-23 15:22:29
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Simplified Vehicle Vibration Modeling for Image Sensor Communication
摘要： Image sensor communication (ISC), derived from visible light communication (VLC) is an attractive solution for outdoor mobile environments, particularly for intelligent transport systems (ITS). In ITS-ISC, tracking a transmitter in the image plane is critical issue since vehicle vibrations make it difficult to select the correct pixels for data reception. Our goal in this study is to develop a precise tracking method. To accomplish this, vehicle vibration modeling and its parameters estimation, i.e., representative frequencies and their amplitudes for inherent vehicle vibration, and the variance of the Gaussian random process representing road surface irregularity, are required. In this paper, we measured actual vehicle vibration in a driving situation and determined parameters based on the frequency characteristics. Then, we demonstrate that vehicle vibration that induces transmitter displacement in an image plane can be modeled by only Gaussian random processes that represent road surface irregularity when a high frame rate (e.g., 1000 fps) image sensor is used as an ISC receiver. The simplified vehicle vibration model and its parameters are evaluated by numerical analysis and experimental measurement and obtained result shows that the proposed model can reproduce the characteristics of the transmitter displacement sufficiently.
关键词： vehicle motion model,vehicle vibration,visible light communication,image sensor communication,road surface irregularity,transmitter displacement
更新于2025-09-23 15:22:29
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Estimation of Energy and Time Savings in Optical Glass Manufacturing When Using Ultrasonic Vibration-Assisted Grinding
摘要： Energy and time savings are highly important aspects of green manufacturing. Ultrasonic vibration-assisted grinding (UVAG) is a high-efficiency, low-energy-consumption processing method for optical components made from hard and brittle materials. This work presents an experimental investigation of the specific grinding energy and the subsurface damage depth in UVAG of optical glasses to estimate the increased energy and time savings produced when using UVAG in optical glass manufacturing. The normal and tangential grinding forces of traditional grinding (TG) and axial UVAG processes on optical glasses were investigated for various machining parameters. The specific grinding energies during the TG and UVAG of the optical glasses were calculated and analyzed from the perspective of the energy consumption of the grinding process. The subsurface damage depths in optical glass during TG and UVAG were measured as an estimate of the machining quality, and the magnetorheological polishing spot method was used to analyze the time saved in subsequent polishing processes. The results show that UVAG can reduce energy consumption during the grinding of glass and produce significant time savings in subsequent polishing processes. The UVAG process therefore shows good potential for use in green manufacturing of optical components.
关键词： Energy saving,Sub-surface damage,Ultrasonic vibration-assisted grinding,Specific grinding energy
更新于2025-09-23 15:22:29