scholarly journals Performance enhancement of nonlinear asymmetric bistable energy harvesting from harmonic, random and human motion excitations

2019 ◽  
Author(s):  
Chris Bowen
Keyword(s):  
Energy Harvesting ◽  
Power Output ◽  
Lower Limb ◽  
Performance Enhancement ◽  
Basin Of Attraction ◽  
Harmonic Excitation ◽  
Human Motion ◽  
Experimental Investigations ◽  
Energy Harvesters ◽  
Negative Effect

Numerical and experimental investigations of nonlinear bistable energy harvesters (BEHs) with asymmetric potential functions are presented under various excitations for performance enhancement. Basin of attraction under harmonic excitation indicates that asymmetric potentials in BEHs have negative effect on the power output. Therefore, a proper bias angle is introduced to the asymmetric potential BEHs for performance enhancement. Numerical and experimental results show that the power output is actually improved in a certain bias angle range under harmonic and random excitations. Furthermore, experiments under human motion excitation demonstrate that the asymmetric potential BEHs could perfectly combine with the asymmetric motion of lower-limb to improve the performance.

Influence of Bias Angle on Output Performance of Nonlinear Asymmetric Energy Harvesters: Experimental Investigation

2018 ◽  
Author(s):  
Wei Wang ◽  
Junyi Cao ◽  
Ying Zhang ◽  
Chris R. Bowen
Keyword(s):  
Energy Harvesting ◽  
Power Output ◽  
Performance Enhancement ◽  
Vibrational Energy ◽  
Experimental System ◽  
Harmonic Excitation ◽  
Nonlinear Phenomena ◽  
Energy Harvesters ◽  
Output Performance ◽  
Piezoelectric Energy

In recent decades, the technique of piezoelectric energy harvesting has drawn a great deal of attention since it is a promising method to convert vibrational energy to electrical energy to supply lower-electrical power consumption devices. The most commonly used configuration for energy harvesting is the piezoelectric cantilever beam. Due to the inability of linear energy harvesting to capture broadband vibrations, most researchers have been focusing on broadband performance enhancement by introducing nonlinear phenomena into the harvesting systems. Previous studies have often focused on the symmetric potential harvesters excited in a fixed direction and the influence of the gravity of the oscillators was neglected. However, it is difficult to attain a completely symmetric energy harvester in practice. Furthermore, the gravity of the oscillator due to the change of installation angle will also exert a dramatic influence on the power output. Therefore, this paper experimentally investigates the influence of gravity due to bias angle on the output performance of asymmetric potential energy harvesters under harmonic excitation. An experimental system is developed to measure the output voltages of the harvesters at different bias angles. Experimental results show that the bias angle has little influence on the performance of linear and monostable energy harvesters. However, for an asymmetric potential bistable harvester with sensitive nonlinear restoring forces, the bias angle influences the power output greatly due to the effect of gravity. There exists an optimum bias angle range for the asymmetric potential bistable harvester to generate large output power in a broader frequency range. The reason for this phenomenon is that the influence of gravity due to bias angle will balance the nonlinear asymmetric potential function in a certain range, which could be applied to improve the power output of asymmetric bistable harvesters.

Geometric and Material Optimization of Vortex-Induced Vibration Micro Energy Harvesters for Localized Wind Environments

2012 ◽  
Author(s):  
Jesse J. French ◽  
Colton T. Sheets
Keyword(s):  
Energy Harvesting ◽  
Power Output ◽  
Fluid Velocity ◽  
Frequency Variation ◽  
Vortex Induced Vibration ◽  
Energy Harvesters ◽  
Wind Speeds ◽  
Material Optimization ◽  
Piezoelectric Energy ◽  
Wind Velocities

Wind energy capture in today’s environment is often focused on producing large amounts of power through massive turbines operating at high wind speeds. The device presented by the authors performs on the extreme opposite scale of these large wind turbines. Utilizing vortex induced vibration combined with developed and demonstrated piezoelectric energy harvesting techniques, the device produces power consistent with peer technologies in the rapidly growing field of micro-energy harvesting. Vortex-induced vibrations in the Karman vortex street are the catalyst for energy production of the device. To optimize power output, resonant frequency of the harvester is matched to vortex shedding frequency at a given wind speed, producing a lock-on effect that results in the greatest amplitude of oscillation. The frequency of oscillation is varied by altering the effective spring constant of the device, thereby allowing for “tuning” of the device to specific wind environments. While localized wind conditions are never able to be predicted with absolute certainty, patterns can be established through thorough data collection. Sampling of local wind conditions led to the design and testing of harvesters operating within a range of wind velocities between approximately 4 mph and 25 mph. For the extremities of this range, devices were constructed with resonant frequencies of approximately 17 and 163 Hz. Frequency variation was achieved through altering the material composition and geometry of the energy harvester. Experimentation was performed on harvesters to determine power output at optimized fluid velocity, as well as above and below. Analysis was also conducted on shedding characteristics of the device over the tested range of wind velocities. Computational modeling of the device is performed and compared to experimentally produced data.

A parametric analysis of the nonlinear dynamics of bistable vibration-based piezoelectric energy harvesters

2020 ◽  
pp. 1045389X2096318
Author(s):  
Luã Guedes Costa ◽  
Luciana Loureiro da Silva Monteiro ◽  
Pedro Manuel Calas Lopes Pacheco ◽  
Marcelo Amorim Savi
Keyword(s):  
Nonlinear Dynamics ◽  
Energy Harvesting ◽  
Parametric Analysis ◽  
Electromechanical Coupling ◽  
Performance Enhancement ◽  
Piezoelectric Materials ◽  
Electrical Power ◽  
Harmonic Excitation ◽  
Piezoelectric Energy ◽  
Harvesting Systems

Piezoelectric materials exhibit electromechanical coupling properties and have been gained importance over the last few decades due to their broad range of applications. Vibration-based energy harvesting systems have been proposed using the direct piezoelectric effect by converting mechanical into electrical energy. Although the great relevance of these systems, performance enhancement strategies are essential to improve the applicability of these system and have been studied substantially. This work addresses a numerical investigation of the influence of cubic polynomial nonlinearities in energy harvesting systems considering a bistable structure subjected to harmonic excitation. A deep parametric analysis is carried out employing nonlinear dynamics tools. Results show complex dynamical behaviors associated with the trigger of inter-well motion. Electrical power output and efficiency are monitored in order to evaluate the configurations associated with best system performances.

scholarly journals On the Effects of Structural Coupling on Piezoelectric Energy Harvesting Systems Subject to Random Base Excitation

Aerospace ◽  
2020 ◽  
Vol 7 (7) ◽  
pp. 93
Author(s):  
Hamidreza Masoumi ◽  
Hamid Moeenfard ◽  
Hamed Haddad Khodaparast ◽  
Michael I. Friswell
Keyword(s):  
Energy Harvesting ◽  
Mechanical Response ◽  
Harmonic Excitation ◽  
Point Of View ◽  
Analytical Models ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Novel Approach ◽  
Band Limited ◽  
Multi Body

The current research investigates the novel approach of coupling separate energy harvesters in order to scavenge more power from a stochastic point of view. To this end, a multi-body system composed of two cantilever harvesters with two identical piezoelectric patches is considered. The beams are interconnected through a linear spring. Assuming a stochastic band limited white noise excitation of the base, the statistical properties of the mechanical response and those of the generated voltages are derived in closed form. Moreover, analytical models are derived for the expected value of the total harvested energy. In order to maximize the expected generated power, an optimization is performed to determine the optimum physical and geometrical characteristics of the system. It is observed that by properly tuning the harvester parameters, the energy harvesting performance of the structure is remarkably improved. Furthermore, using an optimized energy harvester model, this study shows that the coupling of the beams negatively affects the scavenged power, contrary to the effect previously demonstrated for harvesters under harmonic excitation. The qualitative and quantitative knowledge resulting from this analysis can be effectively employed for the realistic design and modelling of coupled multi-body structures under stochastic excitations.

scholarly journals VIBRATION ENERGY HARVESTING TECHNIQUE: A COMPREHENSIVE REVIEW

2020 ◽  
Vol 4 (2) ◽  
pp. 46-48
Author(s):  
Nik Fakhri Nek Daud ◽  
Ruzlaini Ghoni
Keyword(s):  
Energy Harvesting ◽  
Power Output ◽  
Energy Conversion Efficiency ◽  
Vibration Energy Harvesting ◽  
Energy Harvesters ◽  
Output Performance ◽  
Harvesting Technique ◽  
External Power Source ◽  
External Power ◽  
Future Requirement

In order to minimize the requirement of external power source and maintenance for electric devices such as wireless sensor networks, the energy harvesting technique based on vibrations has been a dynamic field of studying interest over past years. Researchers have concentrated on developing efficient energy harvesters by adopting new materials and optimizing the harvesting devices. One important limitation of existing energy harvesting techniques is that the power output performance is seriously subject to the resonant frequencies of ambient vibrations, which are often random and broadband. This paper reviews important vibration-to-electricity conversion mechanisms, including theory, modelling methods and the realizations of the piezoelectric, electromagnetic and electrostatic approaches. Different types of energy harvesters that have been designed with nonlinear characteristics are also reviewed. As one of important factors to estimate the power output performance, the energy conversion efficiency of different conversion mechanisms is also summarized. Finally, the challenging issues based on the existing methods and future requirement of energy harvesting are also discussed.

Bistable Energy Harvesting From Human Motion

2015 ◽  
Author(s):  
Wei Wang ◽  
Junyi Cao ◽  
Shengxi Zhou ◽  
Jing Lin
Keyword(s):  
Energy Harvesting ◽  
Human Motion ◽  
Ambient Vibration ◽  
Energy Output ◽  
Potential Well ◽  
Energy Devices ◽  
Energy Harvesters ◽  
Cantilever Structure ◽  
Well Function ◽  
Nonlinear Energy

Recently, the power supply for portable electronic devices using the electricity extracted from human motion and ambient vibrations has received considerable attention from multidiscipline field. Among many energy converting mechanisms, the ease miniaturization of piezoelectric cantilever structure propels many research groups to investigate the potential of efficient energy harvesting from ambient vibration using resonant phenomena. However, the incapability of traditional linear energy harvesting from low frequency or varying frequency vibrations has become an open issue. This paper investigates the feasibility of nonlinear energy harvesters with different bistable potential well functions in harvesting energy from walking and running vibration. The portable nonlinear energy harvesting device and its measurement system has been established to obtain the model parameter and excitation signal from human motion. The electromechanical model for bistable energy harvesters with different nonlinear restoring force is derived from theoretical method and experimental data. Numerical investigation under human walking and running vibrations shows that large amplitude interwell motion are easily achieved to improve energy output while the proper potential well function of bistable oscillators is designed. The comparative experiments for nonlinear energy devices with different potential well function are performed. The history and frequency spectrum of output voltage demonstrate the effectiveness of numerical simulation and the clear potential of bistable energy harvesting from human motion by means of appropriate potential function design.

scholarly journals Simply-supported multi-layered beams for energy harvesting

2016 ◽  
Vol 28 (6) ◽  
pp. 740-759 ◽  
Author(s):  
Rupesh Patel ◽  
Yoshikazu Tanaka ◽  
Stewart McWilliam ◽  
Hidemi Mutsuda ◽  
Atanas A Popov
Keyword(s):  
Energy Harvesting ◽  
Resonant Frequency ◽  
Unit Volume ◽  
Large Range ◽  
Experimental Investigations ◽  
Simply Supported ◽  
Energy Harvesters ◽  
Layered Beams ◽  
Unbiased Manner ◽  
Made In

This paper develops an analytical model for predicting the performance of simply-supported multi-layered piezoelectric vibrating energy harvesters. The model includes the effects of material and geometric non-linearities, as well as axial pre-tension/compression, and is validated against experimental devices for a large range of base accelerations. Numerical and experimental investigations are performed to understand the benefits of using simply-supported devices compared to cantilevered devices. Comparisons are made in an unbiased manner by tuning the resonant frequency to the same value by modifying the geometry, and the results obtained indicate that simply-supported devices are capable of generating higher voltage levels than cantilever devices. The model is also used to investigate the benefits of using multi-layered devices to improve power density. Depending on harvester composition, power-per-unit-volume of piezoelectric material for a device is increased through the stacking of layers.

Tristable Energy Harvesters With Asymmetric Potential Wells: Analytical Study

2017 ◽  
Author(s):  
Shengxi Zhou ◽  
Lei Zuo
Keyword(s):  
Energy Harvesting ◽  
High Energy ◽  
Harmonic Excitation ◽  
Potential Wells ◽  
Potential Barriers ◽  
Energy Harvesters ◽  
Response Characteristics ◽  
The Stability ◽  
Excitation Conditions ◽  
Main Factor

In order to reveal the nonlinear response characteristics of asymmetric tristable energy harvesters, this paper originally deduces their complete harmonic balance solutions. In addition, the Jacobian matrix for determining the stability of these analytical solutions is presented. Under different harmonic excitation conditions, the multi-solution response characteristics of asymmetric tristable energy harvesters are analyzed. In detail, asymmetric tristable energy harvesters are found to have seven solutions (four stable solutions) under the appropriate excitation condition. The influence mechanism of asymmetry of potential wells on tristable energy harvesting performance is studied. The results show that the potential barrier is a main factor to influence high-energy interwell oscillation orbit height, which determines the output voltage amplitude and the overall energy harvesting performance. The influence essence of asymmetry for tristable energy harvesters is to change their potential wells and adjust the distribution of their potential barriers.

Analytical and Numerical Investigations on a Bistable System for Energy Harvesting Application

2014 ◽  
Author(s):  
Matthias Heymanns ◽  
Peter Hagedorn
Keyword(s):  
Energy Harvesting ◽  
Analytical Description ◽  
Harmonic Excitation ◽  
Design Criterion ◽  
Bistable System ◽  
Energy Harvest ◽  
Energy Harvesters ◽  
Critical Excitation ◽  
Nonlinear Energy

This paper aims at an analytical and numerical analysis of a bistable Duffing equation. One purpose lies in the identification of suitable oscillations for a robust energy harvesting device, i.e. a system that is well suited for a broad bandwidth excitation. A map is constructed illustrating the dependence of the harvested energy on the predominant oscillation type. It shows that inter-well oscillations lead to the highest energy harvest compared to intra-well and cross-well oscillations under harmonic excitation. The determination of the critical excitation parameters necessary to maintain inter-well oscillations is essential for the design of bistable energy harvesters. Therefore, investigations are made to attain an analytical description of the inter-well oscillation region. On this basis, a design criterion is derived for nonlinear energy harvesters.

Robust and adaptive control of coexisting attractors in nonlinear vibratory energy harvesters

2017 ◽  
Vol 24 (12) ◽  
pp. 2532-2541 ◽  
Author(s):  
Ashkan Haji Hosseinloo ◽  
Jean-Jacques Slotine ◽  
Konstantin Turitsyn
Keyword(s):  
Energy Harvesting ◽  
Sliding Mode ◽  
High Energy ◽  
Harmonic Excitation ◽  
Coexisting Attractors ◽  
Vibration Energy Harvesting ◽  
Energy Harvesters ◽  
Adaptive Sliding Mode Controller ◽  
Narrow Bandwidth ◽  
Harvesting Systems

An immense body of research has focused on nonlinear vibration energy harvesting systems mainly because of the inherent narrow bandwidth of their linear counterparts. However, nonlinear systems driven by harmonic excitation often exhibit coexisting periodic or chaotic attractors. For effective energy harvesting, it is always desired to operate on the high-energy periodic orbits; therefore, it is crucial for the harvester to move to the desired attractor once the system is trapped in any other coexisting attractor. Here we propose a robust and adaptive sliding mode controller to move the nonlinear harvester to any desired attractor by a short entrainment on the desired attractor. The proposed controller is robust to disturbances and unmodeled dynamics and adaptive to the system parameters. The results show that the controller can successfully move the harvester to the desired attractor, even when the parameters are unknown, in a reasonable period of time, in less than 30 cycles of the excitation force.

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