scholarly journals Data-Driven Optimization of Piezoelectric Energy Harvesters via Pattern Search Algorithm

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 561
Author(s):  
Yang Huang ◽  
Zhiran Yi ◽  
Guosheng Hu ◽  
Bin Yang
Keyword(s):  
Resonant Frequency ◽  
Output Power ◽  
Search Algorithm ◽  
Rank Correlation ◽  
Pattern Search ◽  
Data Driven ◽  
Optimization Strategy ◽  
Energy Harvesters ◽  
Spearman’S Rank Correlation ◽  
Piezoelectric Energy

A data-driven optimization strategy based on a generalized pattern search (GPS) algorithm is proposed to automatically optimize piezoelectric energy harvesters (PEHs). As a direct search method, GPS can iteratively solve the derivative-free optimization problem. Taking the finite element method (FEM) as the solver and the GPS algorithm as the optimizer, the automatic interaction between the solver and optimizer ensures optimization with minimum human efforts, saving designers’ time and performing a more precise exploration in the parameter space to obtain better results. When employing it for the optimization of PEHs, the optimal length and thickness of PZT were 6.0 mm and 4.6 µm, respectively. Compared with reported high-output PEHs, this optimal structure showed an increase of 371% in output power, an improvement by 1000% in normalized power density, and a reduction of 254% in resonant frequency. Furthermore, Spearman’s rank correlation coefficient was calculated for evaluating the correlation among geometric parameters and output performance such as resonant frequency and output power, which provides a data-based perspective on the design and optimization of PEHs.

scholarly journals Bandwidth Broadening of Piezoelectric Energy Harvesters Using Arrays of a Proposed Piezoelectric Cantilever Structure

Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 973
Author(s):  
Marwa S. Salem ◽  
Shimaa Ahmed ◽  
Ahmed Shaker ◽  
Mohammad T. Alshammari ◽  
Kawther A. Al-Dhlan ◽  
...  
Keyword(s):  
Resonant Frequency ◽  
Piezoelectric Material ◽  
Output Power ◽  
Energy Harvester ◽  
Vibration Source ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Narrow Bandwidth ◽  
Cantilever Structure ◽  
Bandwidth Broadening

One of the most important challenges in the design of the piezoelectric energy harvester is its narrow bandwidth. Most of the input vibration sources are exposed to frequency variation during their operation. The piezoelectric energy harvester’s narrow bandwidth makes it difficult for the harvester to track the variations of the input vibration source frequency. Thus, the harvester’s output power and overall performance is expected to decline from the designed value. This current study aims to solve the problem of the piezoelectric energy harvester’s narrow bandwidth. The main objective is to achieve bandwidth broadening which is carried out by segmenting the piezoelectric material of the energy harvester into n segments; where n could be more than one. Three arrays with two, four, and six beams are shaped with two piezoelectric segments. The effect of changing the length of the piezoelectric material segment on the resonant frequency, output power, and bandwidth, as well as the frequency response is investigated. The proposed piezoelectric energy harvesters were implemented utilizing a finite element method (FEM) simulation in a MATLAB environment. The results show that increasing the number of array beams increases the output power and bandwidth. For the three-beam arrays, at n equals 2, 6 mW output power and a 9 Hz bandwidth were obtained. Moreover, the bandwidth of such arrays covered around 5% deviation from its resonant frequency. All structures were designed to operate as a steel wheel safety sensor which could be used in train tracks.

scholarly journals Power Density Improvement of Piezoelectric Energy Harvesters via a Novel Hybridization Scheme with Electromagnetic Transduction

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 803
Author(s):  
Zhongjie Li ◽  
Chuanfu Xin ◽  
Yan Peng ◽  
Min Wang ◽  
Jun Luo ◽  
...  
Keyword(s):  
Power Density ◽  
Output Power ◽  
Energy Harvester ◽  
Hybrid Energy ◽  
Energy Harvesters ◽  
Piezoelectric Patch ◽  
Piezoelectric Energy ◽  
Electromagnetic Transduction ◽  
Self Powered ◽  
Power Densities

A novel hybridization scheme is proposed with electromagnetic transduction to improve the power density of piezoelectric energy harvester (PEH) in this paper. Based on the basic cantilever piezoelectric energy harvester (BC-PEH) composed of a mass block, a piezoelectric patch, and a cantilever beam, we replaced the mass block by a magnet array and added a coil array to form the hybrid energy harvester. To enhance the output power of the electromagnetic energy harvester (EMEH), we utilized an alternating magnet array. Then, to compare the power density of the hybrid harvester and BC-PEH, the experiments of output power were conducted. According to the experimental results, the power densities of the hybrid harvester and BC-PEH are, respectively, 3.53 mW/cm3 and 5.14 μW/cm3 under the conditions of 18.6 Hz and 0.3 g. Therefore, the power density of the hybrid harvester is 686 times as high as that of the BC-PEH, which verified the power density improvement of PEH via a hybridization scheme with EMEH. Additionally, the hybrid harvester exhibits better performance for charging capacitors, such as charging a 2.2 mF capacitor to 8 V within 17 s. It is of great significance to further develop self-powered devices.

Performance analysis of a lever piezoelectric energy harvester for roadway applications

2021 ◽  
pp. 1045389X2110014
Author(s):  
Guangya Ding ◽  
Hongjun Luo ◽  
Jun Wang ◽  
Guohui Yuan
Keyword(s):  
Output Power ◽  
Energy Harvester ◽  
Open Circuit ◽  
Traffic Load ◽  
Energy Harvesters ◽  
Speed Sensor ◽  
Piezoelectric Energy ◽  
Optimal Load ◽  
Self Powered ◽  
Output Characteristics

A novel lever piezoelectric energy harvester (LPEH) was designed for installation in an actual roadway for energy harvesting. The model incorporates a lever module that amplifies the applied traffic load and transmits it to the piezoelectric ceramic. To observe the piezoelectric growth benefits of the optimized LPEH structure, the output characteristics and durability of two energy harvesters, the LPEH and a piezoelectric energy harvester (PEH) without a lever, were measured and compared by carrying out piezoelectric performance tests and traffic model experiments. Under the same loading condition, the open circuit voltages of the LPEH and PEH were 20.6 and 11.7 V, respectively, which represents a 76% voltage increase for the LPEH compared to the PEH. The output power of the LPEH was 21.51 mW at the optimal load, which was three times higher than that of the PEH (7.45 mW). The output power was linearly dependent on frequency and load, implying the potential application of the module as a self-powered speed sensor. When tested during 300,000 loading cycles, the LPEH still exhibited stable structural performance and durability.

scholarly journals Simultaneous Feature Selection and Support Vector Machine Optimization Using an Enhanced Chimp Optimization Algorithm

Algorithms ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 282
Author(s):  
Di Wu ◽  
Wanying Zhang ◽  
Heming Jia ◽  
Xin Leng
Keyword(s):  
Optimization Algorithm ◽  
Classification Accuracy ◽  
Search Algorithm ◽  
Rank Correlation ◽  
Population Diversity ◽  
The Other ◽  
Support Vector ◽  
Local Optimum ◽  
Original Algorithm ◽  
Spearman’S Rank Correlation

Chimp Optimization Algorithm (ChOA), a novel meta-heuristic algorithm, has been proposed in recent years. It divides the population into four different levels for the purpose of hunting. However, there are still some defects that lead to the algorithm falling into the local optimum. To overcome these defects, an Enhanced Chimp Optimization Algorithm (EChOA) is developed in this paper. Highly Disruptive Polynomial Mutation (HDPM) is introduced to further explore the population space and increase the population diversity. Then, the Spearman’s rank correlation coefficient between the chimps with the highest fitness and the lowest fitness is calculated. In order to avoid the local optimization, the chimps with low fitness values are introduced with Beetle Antenna Search Algorithm (BAS) to obtain visual ability. Through the introduction of the above three strategies, the ability of population exploration and exploitation is enhanced. On this basis, this paper proposes an EChOA-SVM model, which can optimize parameters while selecting the features. Thus, the maximum classification accuracy can be achieved with as few features as possible. To verify the effectiveness of the proposed method, the proposed method is compared with seven common methods, including the original algorithm. Seventeen benchmark datasets from the UCI machine learning library are used to evaluate the accuracy, number of features, and fitness of these methods. Experimental results show that the classification accuracy of the proposed method is better than the other methods on most data sets, and the number of features required by the proposed method is also less than the other algorithms.

Fabrication and analytical modeling of transverse mode piezoelectric energy harvesters

2012 ◽  
Vol 1397 ◽  
Author(s):  
Seon-Bae Kim ◽  
Jung-Hyun Park ◽  
Seung-Hyun Kim ◽  
Hosang Ahn ◽  
H. Clyde Wikle ◽  
...  
Keyword(s):  
Output Power ◽  
Analytical Modeling ◽  
Energy Harvester ◽  
Power Conversion ◽  
Transverse Mode ◽  
Modified Model ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Interdigital Electrodes ◽  
Piezoelectric Cantilever

ABSTRACTA transverse (d33) mode piezoelectric cantilever was fabricated for energy harvesting. Various dimensions of interdigital electrodes (IDE) were deposited on a piezoelectric layer to examine the effects of electrode design on the performance of energy harvesters. Modeling was performed to calculate the output power of the devices. The estimation was based on Roundy’s analytical modeling derived for a d31 mode piezoelectric energy harvester (PEH). In order to apply the Roundy’s model to d33 mode PEH, the IDE configuration was converted to the area of top and bottom electrodes (TBE). The power conversion in d33 mode PEH was commonly estimated by the product of piezoelectric layer’s thickness and finger electrode’s length. In addition, the spacing between fingers was regarded as gap between top and bottom electrodes. However, the output power in a transverse mode PEH increases continuously with the increase of finger spacing, which does not correspond to experimental results. In this research, the dimension of IDE was converted to that of TBE using conformal mapping, and variation of power of PEH was remodeled. The modified model suggests that the maximum power in a transverse mode PEH is obtained when the finger spacing is identical with effective finger spacing. The output power then decreases when finger spacing is larger than effective finger spacing. The decrease of efficiency may result from insufficient degree of poling and increased charged defect with increasing finger spacing.

scholarly journals Design and Analysis of a Magnetically Coupled Multi-Frequency Hybrid Energy Harvester

Sensors ◽  
2019 ◽  
Vol 19 (14) ◽  
pp. 3203 ◽  
Author(s):  
Zhenlong Xu ◽  
Hong Yang ◽  
Hao Zhang ◽  
Huawei Ci ◽  
Maoying Zhou ◽  
...  
Keyword(s):  
Output Power ◽  
Electromechanical Coupling ◽  
Energy Harvester ◽  
Hybrid Energy ◽  
Energy Harvesters ◽  
Peak Output Power ◽  
Piezoelectric Energy ◽  
Operating Bandwidth ◽  
Frequency Sweep Test ◽  
Hybrid Energy Harvesting

The approach to improve the output power of piezoelectric energy harvester is one of the current research hotspots. In the case where some sources have two or more discrete vibration frequencies, this paper proposed three types of magnetically coupled multi-frequency hybrid energy harvesters (MHEHs) to capture vibration energy composed of two discrete frequencies. Electromechanical coupling models were established to analyze the magnetic forces, and to evaluate the power generation characteristics, which were verified by the experimental test. The optimal structure was selected through the comparison. With 2 m/s2 excitation acceleration, the optimal peak output power was 2.96 mW at 23.6 Hz and 4.76 mW at 32.8 Hz, respectively. The superiority of hybrid energy harvesting mechanism was demonstrated. The influences of initial center-to-center distances between two magnets and length of cantilever beam on output power were also studied. At last, the frequency sweep test was conducted. Both theoretical and experimental analyses indicated that the proposed MHEH produced more electric power over a larger operating bandwidth.

Modeling of V-Shaped Beam-Mass Piezoelectric Energy Harvester: Impact of the Angle Between the Beams

2012 ◽  
Author(s):  
Wei-Jiun Su ◽  
Jean W. Zu
Keyword(s):  
Resonant Frequency ◽  
Energy Harvester ◽  
Beam Theory ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Piezoelectric Layers ◽  
Cantilevered Beam ◽  
Power Frequency ◽  
Tip Mass ◽  
Euler Bernoulli Beam

Piezoelectric material has been widely utilized in vibration-based energy harvesters (VEH). The most common configuration of piezoelectric energy harvester is a cantilevered beam with unimorph or bimorph piezoelectric layers. In this paper, a new configuration of PEH is proposed. Two beams are assembled as V shape with tip masses attached. The first beam is a cantilevered beam with tip mass while the second beam is attached to the end of the first beam with a certain angle. Piezoelectric layers are attached to both beams in unimorph configuration for power generation. The analytical solution is derived based on Euler-Bernoulli beam theory. In this analysis, the angle varies from 0 to 135 degree to see the influence of angle on voltage and power frequency response. The V-shaped VEH is proven to have the second resonant frequency relatively close to the first resonant frequency when compared with conventional cantilevered VEH. Furthermore, the angle between the two beams will influence the ratio of the second to the first resonant frequency. By choosing a suitable angle, the V-shaped structure can effectively broaden the bandwidth.

Optimization for the Harvesting Structure of the Piezoelectric Bimorph Energy Harvesters Circular Plate by Reduced Order Finite Element Analysis

2016 ◽  
Vol 08 (03) ◽  
pp. 1650029 ◽  
Author(s):  
A. N. Solovyev ◽  
L. V. Duong
Keyword(s):  
Finite Element ◽  
Resonant Frequency ◽  
Circular Plate ◽  
Flexural Vibration ◽  
Detailed Calculation ◽  
Piezoelectric Bimorph ◽  
Element Analysis ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Exciting Frequency

The power generation efficiency of piezoelectric energy harvesters is dependent on the coupling of their resonant frequency with that of the source vibration. The mechanical design of the energy harvester plays an important role in defining the resonant frequency characteristics of the system and therefore in order to maximize power density, it is important for a designer to be able to model, simulate and optimize designs to match new target applications. This paper gives a detailed calculation of piezoelectric energy harvesters that is in the form of a bimorph-circular plate fixed in the contour in the device frame by finite element (FE) analysis using the commercially available software package ANSYS, ACELAN. The piezoelectric bimorph is assumed to be driven into flexural vibration by an ambient acoustic source to convert the mechanical energies into electric energies. The optimal design was based on matching the resonant frequency of the device with the environmental exciting frequency, and balancing the output voltage. The simplified models of the account of a proof mass are offered. On the basis of calculations, the most effective construction of the device is offered that exhibit the targeted resonant frequency response chosen by the designer.

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