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Energy harvesting for self-powered systems
(2020-07-01)
Nundrakwang, Songmoung
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Yingyong, Phonexai
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Isarakorn, Don
Harvesting energy from waste energy sources in ambient environmental is the accessible technology in the field of self-power electronic devices for high-efficiency energy due to the power consumption of modern electronic devices that are rapidly developed to microwatt, low-cost, lightweight, and small size. Since numerous research are investigated the technique for converting the ambient energy into useable electrical energy for practical application. Including light, thermal gradients, vibration or motion, and radio-frequency electromagnetic radiation, various forms of waste energy sources are proposed in this review. Their existing power density in the ambient environment is demonstrated. Moreover, the fundamental theory and the application of the energy harvesting devices are discussed as a foundation of the energy conversion technology for self-power electronic devices such as handheld, wearable, and portable devices.
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A Comparative Study of the Electrical Characteristics of Piezoelectric and Triboelectric Nanogenerators for Energy-Harvesting Floor Tiles
(2020-06-01)
Yingyong, Phonexai
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Thainiramit, Panu
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Nundrakwang, Songmoung
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Janphuang, Pattanaphong
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Isarakorn, Don
Piezoelectric and Triboelectric nanogenerators (PENG and TENG) have gained significant attention for use in self-powered electronics and sensing systems. They also have high potential to harvest energy from low-frequency vibration sources in the ambient environment. This paper investigated the performance and behavior of the two aforementioned nanogenerators based on energy-harvesting floor tiles by using a test bench to demonstrate the electrical characteristics output and comparing their power density output, energy density output, and other properties for characterization and scale-up in practical applications. The input used in the experiment varied the gap distance of the cover plate for the test bench with constant pneumatic pressure to excite the cover plate. The experimental results showed that the power density and energy density of PENG were higher than those of the TENG. The power density and energy density measured in 10 s under 2 Hz of input excitation of PENG and TENG at the gap width of 5 mm were 5773.35 μW/cm3, 1376.26 μJ/cm3 and 752.34 μW/cm3, 31.32 μJ/cm3, respectively. Due to their high output density, they enable promising possibilities to power small consumption electronics and sensing systems.
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Proposal of the concept of a breathing assist system for saxophone players with breathing problems
(2019-07-01)
Kato, Tomonori
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Shimazaki, Kohei
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Nundrakwang, Songmoung
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Chuprasert, Pavarit
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Thumwarin, Pitak
This research aims to propose the concept of a breathing assist system for saxophone players with breathing problems. First, the quantity of pressure and air flow rate required to play an alto saxophone is determined by certain investigations and experiments. Second, the above-mentioned concept, which works like a pneumatic master-slave amplifier, is proposed and the details of each component are explained.
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Resonance in vocal techniques analysis
(2018-08-13)
Kittimathaveenan, Kajornsak
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Thumwarin, Pitak
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Pakalong, Nattaporn
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Nundrakwang, Songmoung
Singers, especially when they start training, tend to have many questions concerning how to control their body as a musical instrument in order to create the sound they want. The fact that we humans can speak since birth does not mean that everyone can also control their vocal tract to make satisfactory singing sounds. Indeed, some people do not fully understand which organs are involved in the production of human speaking and singing sounds. To effectively teach singers, it is necessary to encourage them to observe the relationship between the voice organ and the sound they hear. This helps them understand which organs produce their singing voice as opposed to everyday speaking sounds. In this study, signal processing principles were used to analyze singing voices with the aim of helping singers and teachers to easily understand the principles of voice production, and with a focus on the effect of singing with nasal resonance. To fulfill this study, singing sounds were recorded and then processed to display the sound spectrum (amplitude of sound at different frequencies). In addition, the relationship between the voice production and the associated sounds were graphically analyzed.
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Comparative study of QCM analyzers based on pierce oscillator and electromechanical impedance techniques
(2017-02-21)
Jayasvasti, Subhawat
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Isarakorn, Don
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Nundrakwang, Songmoung
This paper presents a comparison between pierce oscillator and impedance analysis techniques for measuring the frequency of the quartz crystal. The QCM analyzer based on pierce oscillator is designed, realized, and then compared to the impedance analyzer (Type bode 100). The comparison is focused on accuracy and precision of measurement. The pierce oscillator in a completed-chip is employed in the QCM analyzing device in order to simplify the circuit of system. The frequency drift and standard deviation (SD) values which are obtained from resonant frequency measurement are studied in order to investigate the accurate and precise measurement of devices. In the experiment, an AT-cut quartz disc of crystal oscillator package HC49U is unloaded and loaded while it is being measured the frequency. From the experimental results, the QCM analyzer based on pierce oscillator and impedance analyzer have the approximate accuracy and precision of measurement. The QCM analyzer based on pierce oscillator has lower sensitivity due to the frequency drift.
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Piezoelectric energy harvesting from machine vibrations for wireless sensor system
(2015-08-17)
Panthongsy, Phosy
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Isarakorn, Don
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Sudhawiyangkul, Thapanun
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Nundrakwang, Songmoung
In recent years, wireless sensor network is used in a variety of applications and highly required. These wireless sensor network is powered by the battery with limit energy. Therefore, the integration of energy harvester and wireless sensor network has received more attention because it can prolong the lifetime of battery in a sensor node. The focus of this paper is to design the energy harvesting device from machine vibrations for wireless sensor node, which the amplitude and frequency of vibration source were contributed on the design. The structure of energy harvesting devices is a resonant type piezoelectric energy harvester with a proof mass at the tip of the beam for tuning its resonant frequency. The proposed piezoelectric energy harvesters were then designed and analyzed by using Finite Element Method (FEM) to optimize the natural frequency of the harvester. Then, the prototype energy harvesters were made and mounted to a vibration source for experiments. The result reveals that the optimal piezoelectric energy harvester can generate the output power of 82.29 μW at the resonant frequency of 50 Hz.
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Energy analysis in Zigbee based wireless sensor node powered by piezoelectric energy harvester
(2014-01-01)
Isarakorn, Don
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Sudhawiyangkul, Thapanun
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Nundrakwang, Songmoung
Recently, an integration of wireless sensor network with energy harvesters is getting more interested because it can extend the life time of battery in a sensor node, which is very important in many applications. This paper presents the concept of energy analysis in Zigbee based wireless sensor network, which is powered by a piezoelectric energy harvester to optimize the algorithms used in wireless sensor network. In this work, difference aspects related to piezoelectric energy harvester, characteristic of power consumption in Zigbee based wireless sensor node and concept of optimizing algorithms to balance input and output power in the integrated system are proposed. © (2014) Trans Tech Publications, Switzerland.
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Multivariable control of overhead crane system by CRA method
(2008-12-01)
Nundrakwang, Songmoung
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Benjanarasuth, Taworn
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Ngamwiwit, Jongkol
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Komine, Noriyuki
In this paper, three controllers, namely I-PD, PD and I-P controllers designed by CRA method for simultaneously controlling the trolley position, load-swing angle and hoisting rope length of the overhead crane system is proposed. The non-linear model of the crane system is first approximated to be three transfer functions in accordance with the trolley position, load-swing angle and hoisting rope length respectively. Then, the corresponding parameters of the I-PD, PD and I-P controllers are designed independently based on the appropriate values of generalized time constant and characteristic ratios. The implementation results show the good performances of the overhead crane system controlled by these controllers. The speed adjustment effects and fast rejection of the disturbance effect occurred at the input force of the trolley are also shown by the experimental results. © 2008 SICE.
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Simplified design of I-P controller for speed control of two-inertia system
(2008-12-01)
Suathed, Sataporn
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Nundrakwang, Songmoung
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Benjanarasuth, Taworn
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Ngamwiwit, Jongkol
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Komme, Noriyuki
In this paper, a simplified design of I-P controller for a higher-order plant by using the concept of plant model reduction and the CRA method with less number of characteristic ratios α, is presented. The Padé type approximation method is used to obtain a lower-order plant model of the higher-order plant first. Then an I-P controller is designed for the model by using CRA method with the appropriate values of characteristic ratios in order to obtain the closed-loop step response without overshoot. Finally, the designed I-P controller is employed to control the original higher-order plant. The sufficient performance of the speed control of a two-inertia system employing the I-P controller designed from its lower-order plant model is shown by the simulation results. The simulation results of the speed control in term of varying the value of a factor β greater than one in the design, tracking the motor speed, and rejecting the disturbance effect are also investigated. © 2008 SICE.
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Hybrid controller for rotational inverted pendulum systems
(2008-12-01)
Benjanarasuth, Taworn
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Nundrakwang, Songmoung
In this paper, a controller designed by energy control technique and servo state feedback with minimum-order observer control algorithm to swing up the pendulum of the rotational inverted pendulum system from the natural pendent position to around the upright position and to stabilize the pendulum in upright position is proposed. The proposed control scheme composes of two parts. The first part is the swing-up control using the energy-based controller and the second part is the stabilizing control using the servo state feedback with minimum-order observer controller. From the implementation of the controller to the rotational inverted pendulum system in laboratory, the pendulum can be swung up within a short period of time with small oscillation of the base angle. Furthermore, without changing the parameters of the proposed controller, the responses of the system when changing the length of the pendulum is also shown to demonstrate the robustness of the proposed control system. © 2008 SICE.

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