• 한국정밀공학회지
• /
• 제30권12호
• /
• pp.1341-1347
• /
• 2013

Energy harvesting is a clean technology to obtain energy from the surrounding environment such as wind, sun, vibration and so on. In particular, the current TPMS (Tire Pressure Monitoring Device) is very small and attached to the outside of a vehicle and power supply of the TPMS is limited. Therefore, energy harvesting using vibration energy of piezoelectric materials is important to the TPMS. In this paper, we analyzed several models using ANSYS which is one of the FEA (Finite Element Analysis) package and compared corresponding strain frequency response functions of the TPMS. In addition, we confirmed that dynamic characteristics variations according to geometry changes have effects on the performance of the TPMS.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2007년도 춘계학술대회논문집
• /
• pp.263-263
• /
• 2007

In the future, self-contained sensors and processing units will need on-board, renewable power supplies to be truly autonomous. One way of supplying such power is through energy harvesting, processes by which ambient forms of energy are converted into electricity. One energy harvesting technique involves converting kinetic energy, in the form of vibrations, into electrical energy through the use of piezoelectric materials. Researchers are currently investigating how piezoelectric materials can be used to harvest power. This study examines the use of auxiliary structures, consisting of a mechanical fixture and a lead zirconate/lead titanate (PZT) piezoelectric element, which can be attached to any boundary conditions vibrating beam of the any boundary conditions. Adjusting various boundary conditions of these structures can maximize the strain induced in the attached PZT element and improve power output.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2006년도 춘계학술대회논문집
• /
• pp.827-830
• /
• 2006

With recent advanced in portable electric devices, wireless sensor, MEMS and bio-Mechanics device, the new typed power supply, not conventional battery but self-powered energy source is needed. Particularly, the system that harvests from their environments are interests for use in self powered devices. For very low powered devices, environmental energy may be enough to use power source. In the generality of cases, these energy harvesting systems are used in the piezoelectric materials as mechanisms to convert mechanical vibration energy into electric energy. Through the piezoelectric materials, the ambient vibration energy could be used to prolong the power supply or in the ideal case provide endless energy f9r the devices. Therefore, the piezoelectric power harvesting cantilever beam is developed. Also, the output voltage and power are predicted in this study. We also discuss the developing system of the piezoelectric energy scavenger. An experimental verification of the model is also performed to ensure its accuracy.

• Smart Structures and Systems
• /
• 제32권6호
• /
• pp.383-391
• /
• 2023

Energy harvesting in trams may become a prevalent source of passive energy generation due to the high density of vibrational energy, and this may help power structural health monitoring systems for the trams. This paper presents a broadband vibrational energy harvesting device design that utilizes a varied frequency from a tram vehicle using a 2 DOF vibrational system combined with electromagnetic energy conversion. This paper will demonstrate stepwise optimization processes to determine mechanical parameters for frequency tuning to adjust to the trams' operational conditions, and electromagnetic parameters for the whole system design to maximize power output. The initial optimization will determine 5 important design parameters in a 2 DOF vibrational system, namely the masses (m₁, m₂ (and spring constants (k₁, k₂, k₃). The second step will use these parameters as initial guesses for the second optimization which will maintain the ratios of these parameters and present electrical parameters to maximize the power output from this system. The obtained values indicated a successful demonstration of design optimization as the average power generated increased from 1.475 mW to 17.44 mW (around 12 times).

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2008년도 춘계학술대회논문집
• /
• pp.81-89
• /
• 2008

This paper is concerned with the development of the piezoelectric energy harvesting(PEH) device for ubiquitous sensor node(USN). The USN needs auxiliary power to lengthen its operational life. In this study, the piezoelectric energy harvesting system consisting of a cantilever with a tip mass and piezoelectric wafer was investigated in detail both theoretically and experimentally. The dynamic model for the addressed system was derived using the assumed mode method. The resulting equations of motion were expressed in matrix form, which had never been developed before. The power output characteristics of the PEH was then calculated and discussed. Various experiments were carried out to investigate the charging characteristics of electrical components. Theoretical and experimental results showed that the PEH was able to charge a battery with ambient vibrations but still needed an effective mechanism which can convert mechanical energy to electrical energy and an optimal electric circuit which dissipates small energy.

• 한국소음진동공학회논문집
• /
• 제18권6호
• /
• pp.632-641
• /
• 2008

This paper is concerned with the development of the piezoelectric energy harvesting(PEH) device for ubiquitous sensor node(USN). The USN needs auxiliary power to lengthen its operational life. In this study, the piezoelectric energy harvesting system consisting of a cantilever with a tip mass and piezoelectric wafer was investigated in detail both theoretically and experimentally. The dynamic model for the addressed system was derived using the assumed mode method. The resulting equations of motion were expressed in matrix form, which had never been developed before. The power output characteristics of the PEH was then calculated and discussed. Various experiments were carried out to investigate the charging characteristics of electrical components. Theoretical and experimental results showed that the PEH was able to charge a battery with ambient vibrations but still needed an effective mechanism which can convert mechanical energy to electrical energy and an optimal electric circuit which dissipates small energy.

• 한국소음진동공학회논문집
• /
• 제22권9호
• /
• pp.896-902
• /
• 2012

For most applications of the vibration energy harvesting technology as in wireless sensor networks for smart buildings and plants, the evaluation of DC output performance of vibration energy harvesters is typically required. However, there is no dedicated algorithm for the evaluation. The lack of a dedicated algorithm results from difficulties in the direct incorporation of nonlinear rectifying and regulating circuitry into finite element models of piezoelectric vibration energy harvesters. In this study, we develop a dedicated algorithm and present software based on it for the evaluation of not only AC but also DC electrical quantities. Here, an equivalent electrical circuit model is employed. The COMSOL multiphysics simulation tool is adopted for extracting equivalent electrical circuit parameters of a piezoelectric vibration energy harvester and MATLAB is used to make a graphical user interface. The AC voltage and power outputs calculated by the proposed algorithm under various conditions are compared with those by a traditional finite element analysis. The DC output voltage and power through a rectifier are obtained for varying values of smoothing capacitance and external resistance.

• Smart Structures and Systems
• /
• 제18권3호
• /
• pp.449-470
• /
• 2016

Energy harvesting is an emerging technique that extracts energy from surrounding environments to power low-power devices. For example, it can potentially provide sustainable energy for wireless sensing networks (WSNs) or structural control systems in civil engineering applications. This paper presents a comprehensive study on harvesting energy from earthquake-induced structural vibrations, which is typically of low frequency, to power WSNs. A macroscale pendulum-type electromagnetic harvester (MPEH) is proposed, analyzed and experimentally validated. The presented predictive model describes output power dependence with mass, efficiency and the power spectral density of base acceleration, providing a simple tool to estimate harvested energy. A series of shaking table tests in which a single-storey steel frame model equipped with a MPEH has been carried out under earthquake excitations. Three types of energy harvesting circuits, namely, a resistor circuit, a standard energy harvesting circuit (SEHC) and a voltage-mode controlled buck-boost converter were used for comparative study. In ideal cases, i.e., resistor circuit cases, the maximum electric energy of 8.72 J was harvested with the efficiency of 35.3%. In practical cases, the maximum electric energy of 4.67 J was extracted via the buck-boost converter under the same conditions. The predictive model on output power and harvested energy has been validated by the test data.

• 한국재료학회지
• /
• 제17권12호
• /
• pp.660-663
• /
• 2007

Piezoelectric energy harvesting from our surrounding vibration has been studied for driving the wireless sensor node. To change the vibration energy into the electric-energy efficiently, the natural frequency of cantilever needs to be adjusted to that of a vibration source. When adding 6.80g mass on the end of the fabricated cantilever, a natural frequency shifts from 136 Hz into 49.5 Hz. In addition, electro-mechanical coupling factor increased from 10.20% to 11.90% and resulted in the 1.18 times increase of maximum output power.

• 한국항공우주학회지
• /
• 제44권1호
• /
• pp.40-48
• /
• 2016

관측위성의 고 해상도 임무요구조건 충족을 위해 기계적 구동부를 갖는 탑재장비로부터의 미소진동은 항상 차폐의 대상으로 존재하였다. 본 연구에서는 차폐의 대상이던 미소진동에 주목하여, 전기에너지 재생이 가능하고 동시에 진동절연이 가능한 복합 시스템 구현을 목표로 동조질량 흡진기 형태의 전자기 하베스터와 결합된 수동형 진동절연 시스템을 제안하였다. 아울러 하베스터의 기본특성 측정시험 결과에 기인한 수치해석과 미소진동시험 및 생성전력 측정시험을 통해 본 연구에서 제안한 복합시스템은 미소진동 절연과 동시에 전기에너지 재생에 유효함을 입증하였다.