Fundamental Study on Friction-Driven Gyroscopic Power Generator Works Under Arbitrary Vibration

2019 ◽  
Author(s):  
Aya Watanabe ◽  
Ryousuke Yuyama ◽  
Hiroshi Hosaka ◽  
Akira Yamashita
Keyword(s):  
Power Generation ◽  
High Speed ◽  
Electrical Power ◽  
Low Frequency ◽  
Inertial Force ◽  
Fundamental Study ◽  
Power Generator ◽  
Energy Harvesters ◽  
Low Frequency Vibration ◽  
Circular Track

Abstract This paper describes a friction-driven gyro generator that works under arbitrary vibrations and generates more than 1 W of power. Vibrational generators are energy harvesters that convert environmental vibrations into electrical power via the inertial force of pendulums. In conventional generators that use simple vibration, the power is less than 10 mW for a wearable size because vibrations in the natural environment are as low as 1 Hz. Gyroscopic generators increase the inertial force by rotating a pendulum at high speed and creating a gyro effect. In this generator, a palm-size product that generates 0.1 W and weighs 280 g has already been commercialized, but this device operates only under a particular vibration that synchronizes rotor precession and stalls under random vibration. To solve this problem, in this research, two gimbals and a precession spring are introduced to support the rotor. We developed a prototype generator with straight tracks measuring 16 cm × 11 cm × 12 cm with a mass of 980 g. Under a vibration of 4 Hz and ±20 degrees, power generation of 1.6 W was confirmed. Next, a prototype circular track was made. Power generation of 0.2 W with a vibration of 1 Hz and ±90 degrees was confirmed. Finally, a simple formula to estimate the upper limit of the generation power is derived. It is suggested that the circular-type generator is suitable for low-frequency vibration and can generate twice the power of a straight-type generator.

Development of Small-Sized Motor-Driven Gyroscopic Power Generator Works Under Low-Frequency Vibration

2019 ◽  
Author(s):  
Akio Toyoshima ◽  
Hiroshi Hosaka ◽  
Akira Yamashita
Keyword(s):  
High Speed ◽  
Low Frequency ◽  
Spindle Motor ◽  
Inertia Force ◽  
Power Generator ◽  
Power Generators ◽  
Mechanical Parts ◽  
Low Frequency Vibration ◽  
Generator Type ◽  
Design Freedom

Abstract In order to realize a small-sized energy harvester with high output, this study prototypes a small motor-driven gyroscopic power generator. Supplying energy to sensors and devices is the biggest problem for Internet of Things (IoT) systems. One solution is gyroscopic power generators, which are a type of vibrational generator that amplify the inertia force of weights by rotating them at high speed, and in doing so can obtain greater output than conventional generators that use simple vibration for the same mass weight. This paper reports on a motor-driven type gyroscopic generator in which the flywheel is spun with an embedded motor, and which is superior in applicability to random vibration generators. The generators of this type that have been studied thus far are very large and have been primarily used for wave power generation in the ocean. However, when the shape of this gyroscopic power generator type is miniaturized proportionally, the output per volume decreases in proportion to the fifth power of the dimension. This makes it difficult to maintain the power output while miniaturizing the generator size. In this research, the structure of the gyroscopic power generator is thoroughly refined and miniaturization is realized by making full use of the available space. By using a motor with high design freedom, the spindle motor and flywheel are unified. From this accomplishment, not only is the required space reduced, the number of mechanical parts and the friction loss are decreased as well. The prototype generator has a size of about 150 mm on its long side. When a swinging vibration of 50 degrees in amplitude and 2 Hz in frequency is applied, a net output of 0.104 W is obtained. This output power is sufficient to drive sensors and low power wide area (LPWA) radio circuits.

Multifunctional Energy Harvesting Locally Resonant Metastructures

2017 ◽  
Author(s):  
Christopher Sugino ◽  
Vinciane Guillot ◽  
Alper Erturk
Keyword(s):  
Energy Harvesting ◽  
Low Power ◽  
Electrical Power ◽  
Flexible Structures ◽  
Low Frequency ◽  
Load Resistance ◽  
Modeling Framework ◽  
Energy Harvesters ◽  
Low Frequency Vibration ◽  
Vibration Attenuation

Vibration-based energy harvesting is a growing field for generating low-power electricity to use in wireless electronic devices, such as the sensor networks used in structural health monitoring applications. Locally resonant metastructures, which are structures that comprise locally resonant metamaterial components, enable bandgap formation at wavelengths much longer than the lattice size, for critical applications such as low-frequency vibration attenuation in flexible structures. This work aims to bridge the domains of energy harvesting and locally resonant metamaterials to form multifunctional structures that exhibit both low-power electricity generation and vibration attenuation capabilities. A fully coupled electromechanical modeling framework is developed for two characteristic systems and their modal analysis is presented. Simulations are performed to explore the vibration and electrical power frequency response maps for varying electrical load resistance, and optimal loading conditions are presented. Case studies are presented to understand the interaction of bandgap formation and energy harvesting capabilities of this new class of multifunctional energy-harvesting locally resonant metastructures. It is shown that useful energy can be harvested from the locally resonant metastructure without significantly diminishing their dramatic vibration attenuation in the locally resonant bandgap. Thus, by integrating energy harvesters into a locally resonant metastructure, there is new potential for multifunctional self-powering or self-sensing locally resonant metastructures.

An Experimental Study of Low-Frequency Vibration-Based Electromagnetic Energy Harvesters Used while Walking

2014 ◽  
Vol 918 ◽  
pp. 106-114 ◽  
Author(s):  
Min Chie Chiu ◽  
Ying Chun Chang ◽  
Long Jyi Yeh ◽  
Chiu Hung Chung ◽  
Chen Hsin Chu
Keyword(s):  
Kinetic Energy ◽  
Energy Harvester ◽  
Electrical Power ◽  
Research Work ◽  
Low Frequency ◽  
Electrical Energy ◽  
Electromagnetic Energy ◽  
Electromagnetic System ◽  
Energy Harvesters ◽  
Low Frequency Vibration

The goal of this paper is to develop and experimentally test portable vibration-based electromagnetic energy harvesters which are fit for extracting low frequency kinetic energy. Based on a previous study on fixed vibration-based electromagnetic energy harvesters, three kinds of portable energy harvesters (prototype I, prototype II, and prototype III) are developed and tested. To obtain the related parameters of the energy harvesters, an experimental platform used to measure the vibrational systems electrical power at the resonant frequency and other fixed frequencies is also established. Based on the research work of vibration theory, a low frequency vibration-arm mechanism (prototype III) which is easily in resonance with a walking tempo is developed. Here, a strong magnet fixed to one side of the vibration-arm along with a set of wires placed along the vibrating path will generate electricity. The circular device has a radius of 180 mm, a width of 50 mm, and weighs 200 grams. Because of its light mass, it is easy to carry and put into a backpack. Experimental results reveal that the energy harvester (prototype III) can easily transform kinetic energy into electrical power via the vibration-based electromagnetic system when walking at a normal speed. Consequently, electrical energy reaching 0.25 W is generated from the energy harvester (prototype III) by extracting kinetic energy produced by walking.

scholarly journals Enhanced low-frequency vibration energy harvesting with inertial amplifiers

2021 ◽  
pp. 1045389X2110322
Author(s):  
Sondipon Adhikari ◽  
Arnab Banerjee
Keyword(s):  
Low Frequency ◽  
Vibration Energy ◽  
Vibration Energy Harvesting ◽  
Micro Scale ◽  
Energy Harvesters ◽  
Low Frequency Vibration ◽  
Different Types ◽  
Mechanical Approach ◽  
Ambient Excitation ◽  
Piezoelectric Vibration

Piezoelectric vibration energy harvesters have demonstrated the potential for sustainable energy generation from diverse ambient sources in the context of low-powered micro-scale systems. However, challenges remain concerning harvesting more power from low-frequency input excitations and broadband random excitations. To address this, here we propose a purely mechanical approach by employing inertial amplifiers with cantilever piezoelectric vibration energy harvesters. The proposed mechanism can achieve inertial amplification amounting to orders of magnitude under certain conditions. Harmonic, as well as broadband random excitations, are considered. Two types of harvesting circuits, namely, without and with an inductor, have been employed. We explicitly demonstrate how different parameters describing the inertial amplifiers should be optimally tuned to maximise harvested power under different types of excitations and circuit configurations. It is possible to harvest five times more power at a 50% lower frequency when the ambient excitation is harmonic. Under random broadband ambient excitations, it is possible to harvest 10 times more power with optimally selected parameters.

Electrostatic micro power generation from low-frequency vibration such as human motion

2009 ◽  
Vol 19 (9) ◽  
pp. 094002 ◽  
Author(s):  
Y Naruse ◽  
N Matsubara ◽  
K Mabuchi ◽  
M Izumi ◽  
S Suzuki
Keyword(s):  
Power Generation ◽  
Low Frequency ◽  
Human Motion ◽  
Low Frequency Vibration ◽  
Micro Power

scholarly journals Dynamic Characteristics of Gear Coupling and Rotor System in Transmission Process Considering Misalignment and Tooth Contact Analysis

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1336
Author(s):  
Wei Fan ◽  
Hong Lu ◽  
Yongquan Zhang ◽  
Xiangang Su
Keyword(s):  
Finite Element ◽  
Dynamic Model ◽  
Calculation Method ◽  
High Speed ◽  
Low Frequency ◽  
Rotor System ◽  
Integral Approach ◽  
Time Frequency ◽  
Low Frequency Vibration ◽  
Mass Eccentricity

The dynamic vibration of the gear coupling-rotor system (GCRS) caused by misalignment is an important factor of low frequency vibration and noise radiation of the naval marine. The axial misalignment of gear coupling is inevitable owing to mass eccentricity, and is unconstrained in axial direction at high-speed operation. Therefore, the dynamic model of GCRS is proposed, considering gear-coupling misalignment and contact force in this paper. The whole motion differential equation of GCRS is established based on the finite element method. Moreover, the numerical calculation method of meshing force, considering the uniform distribution load on contact surface, is presented, and the mathematical predictive time–frequency characteristics are analyzed by the Newmark stepwise integral approach. Finally, a reduced-scale application of the propulsion shaft system is utilized to validate the effectiveness of the proposed dynamic model. For the sensibility to low-frequency vibration, the natural frequencies and vibration modes of GCRS are analyzed through the processing and analysis of acceleration signal. The experimental dynamic response and main components of vibration are respectively consistent with mathematical results, which demonstrate the effectiveness of the proposed dynamic model of GCRS with misalignment. Furthermore, it also shows that the proposed finite element analysis and calculation method are suitable for complex shafting, providing a novel thought for dynamic analysis of the propeller–shaft–hull coupled system of marine.

Impedance Control of Gyroscopic Power Generator

2011 ◽  
Author(s):  
Tomoyuki Takahashi ◽  
Jun Iwasaki ◽  
Hiroshi Hosaka
Keyword(s):  
Steady State ◽  
Phase Difference ◽  
High Speed ◽  
Control Method ◽  
Impedance Control ◽  
Low Frequency ◽  
Power Generator ◽  
Communication Devices ◽  
High Speed Rotation ◽  
The Stability

The gyroscopic power generator produces a high-speed rotation of magnets from low-frequency vibrations and supplies electric power to information and communication devices that use human vibrations in daily life. In this paper, in order to increase the stability and the output power of the generator, a simple equation that indicates the steady state approximate solution of the phase difference is derived. From the derived solution, a control method for the steady state is verified by the simulations. In order to maintain the stability and high power generation for variable input vibrations, the impedance control method using the phase difference is developed and verified experimentally.

On electrical optimisation using a Duffing-type vibrational energy harvester

2014 ◽  
Vol 229 (18) ◽  
pp. 3308-3319 ◽  
Author(s):  
Dongxu Su ◽  
Kimihiko Nakano ◽  
Rencheng Zheng ◽  
Matthew P Cartmell
Keyword(s):  
High Speed ◽  
Energy Harvester ◽  
Vibrational Energy ◽  
Electrical Power ◽  
Low Frequency ◽  
Load Resistance ◽  
Ball Screw ◽  
Response Analysis ◽  
Practical Implementation ◽  
Maximum Displacement

There has been much recent interest in the response analysis and optimisation of the linear energy harvester under ambient vibrations. To transfer maximum power to an electrical load in a resonant system, the load resistance should be equal to the sum of the electrical analogue of mechanical damping and internal resistance. However, principally because of the limited bandwidth offered by the linear energy harvester, the potential benefit of nonlinearity has recently been applied to improve the effectiveness of energy harvesting devices. For example, a Duffing-type oscillator can provide a wider bandwidth and greater effectiveness when subject to periodic excitations. The motivating hypothesis has been that the nonlinear Duffing energy harvester can also be optimised to maximise the available electrical power. This paper presents theoretical optimisation and numerical studies under three different conditions with the designed Duffing-type devices. First, the simplest model without any transmission mechanism and optimisation constraints is considered. Second, a device operated under low frequency and large force excitations using a ball screw to convert low-speed linear motion to high-speed rotation is analysed, where the optimum lead and load resistance are derived. Finally, considering the limitation of some dimensions in practical implementation, the constrained optimisation subjected to the maximum displacement of the seismic mass is also shown in this paper.

An Internet-based Exercise as a Component of an Overall Training Program Addressing Medical Aspects of Radiation Emergency Management

2000 ◽  
Vol 15 (2) ◽  
pp. 18-25 ◽  
Author(s):  
Kirsten Levy ◽  
Richard V. Aghababian ◽  
Erwin F. Hirsch ◽  
Domenic Screnci ◽  
Anna Boshyan ◽  
...  
Keyword(s):  
Power Generation ◽  
Nuclear Power ◽  
Electrical Power ◽  
Low Frequency ◽  
Radiation Accident ◽  
Energy Agency ◽  
Political Consequences ◽  
Radiation Accidents ◽  
Medical Response ◽  
The Republic

AbstractThe use of ionizing radiation and radioactive materials continues to increase worldwide in industry, medicine, agriculture, research, electrical power generation, and nuclear weaponry. The risk of terrorism using weapons of mass destruction or simple radiological devices also has increased, leading to heightened concerns. Radiation accidents occur as a consequence of errors in transportation ofradionuclides, use of radiation in medical diagnosis and therapy, industrial monitoring and sterilization procedures, and rarely, nuclear power generation. Compared to other industries, a small number of serious radiation accidents have occurred over the last six decades with recent cases in the Republic of Georgia, Peru, Japan, and Thailand. The medical, psychological, and political consequences of such accidents can be considerable. A number of programs designed to train medical responders in the techniques of radiation accident management have been developed and delivered in many countries. The low frequency of serious radiation accidents requires constant re-training, as skills are lost and medical staff turnover occurs. Not all of the training involves drills or exercises in which responders demonstrate learning or communication over the broad spectrum of medical response capabilities. Medical preparedness within the context of a total emergency response program is lacking in many parts of the world, particularly in Central and Eastern Europe and the Newly Independent States. This paper describes an effort to enhance medical preparedness in the context of a total program of international cooperation and conventions facilitated by the International Atomic Energy Agency. The paper concludes that novel application of telecommunications technology as part of a training activity in radiation accident preparedness can help address gaps in training in this field in which preparedness is essential but experience and practical field exercises are lacking.

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