Isarakorn, Don

Preferred name

Isarakorn, Don

Alternative Name

Isarakorn, D.

Main Affiliation

School of Engineering

don.is@kmitl.ac.th

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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
;
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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DC motor control using CDM based two-degree-of-freedom controller for desired tracking and disturbance rejection characteristics
(2012-12-01)
Isarakorn, Don
This paper focuses on a design of two-degree-of-freedom (2DOF) controller by Coefficient Diagram Method (CDM) for position control of a DC motor. It is known that the 2DOF control system can be designed to meet both tracking and disturbance rejection performances, which are the most important for the position control system. Nevertheless, it requires tuning of many parameters. The CDM is an efficient method in designing the parameters of 2DOF controller based on the stability and the speed of the controlled system so that the desired performance criteria can be met. By the proposed design method, the parameters of 2DOF controller for a DC motor control system are obtained properly without any adjustment. Furthermore, the tracking and disturbance rejection performances are simultaneously designed. The results reveal the versatility of the CDM tuning technique in the position control of a DC motor. © 2012 ICROS.
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Performance evaluation using laser doppler vibrometer sensing technique on advanced lead magnesium niobate-lead titanate piezoelectric-material-based microactuator for hard drive head
(2018-01-01)
Wattananukulchai, Parinya
;
Isarakorn, Don
This paper presents a microactuator for a dual-stage actuator (DSA) of hard disk drive (HDD) based on a lead magnesium niobate-lead titanate (PMN-PT) piezoelectric material and a comparative evaluation of its performance versus that of a traditional lead zirconate titanate (PZT) microactuator using the laser Doppler vibrometer (LDV) sensing technique. PZT microactuator technology has commonly been implemented in the read/write (R/W) magnetic head of HDD. It has a significant function, that is, it moves the magnetic head rapidly and accurately. In order to achieve both accurate positioning control on data tracks and high-speed access across another data track, advanced high-performance actuators and servo control technologies are necessary. An actuator with a wide stroke travel range is essential for HDD as it gives a high-speed access performance. In this study, we focused on comparing the proposed dual-stage PMN-PT head-based actuator with the existing PZT actuator that were mounted on a commercial head gimbal assembly (HGA) using an LDV to determine whether the proposed device could be a worthy replacement of the traditional PZT microactuator. Our experimental results show that the proposed PMN-PT microactuator provided more than twofold improvement in the stroke travel of the R/W magnetic head. Moreover, its dynamic behavior was suitable for assembling a high-density HDD in the future for big data storage without any needs to redesign the HGA nor to costly invest in new assembling machines in a production line. The comparative data of dynamic and static behaviors of PMN-PT versus PZT obtained in this study may be put to good use by sensor designers. Moreover, for many cyber-physical system designers, our data may make them take interest in PMN-PT as a better-performing sensor and an actuator for their systems.
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Primary screening of diabetic retinopathy based on integrating morphological operation and support vector machine
(2017-07-02)
Sreng, Syna
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Maneerat, Noppadol
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Isarakorn, Don
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Hamamoto, Kazuhiko
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Panjaphongse, Ronakorn
Diabetic retinopathy is one of the most frequent causes of blindness due to diabetes. Primary screening is essential due to prerequisite step toward the diagnosis of diabetic retinopathy in order to prevent vision loss or blindness. This paper presents the methods to discriminate between healthy images and diabetic retinopathy images on the retinal images. The proposed method involves three main steps. Initially, the image is preprocessed to remove small noises and enhance the contrast of the image. Secondly, Kirsch edge detection is utilized to detect the bright lesions. Subsequently, the red lesions are detected depending on top-hat morphological filtering methods. Then the bright and dark lesions are combined by using logical AND operator. In order to be left only pathological signs, the noises near the vicinity of the optic disc and blood vessels are further removed using blob analysis. Finally, morphological features are extracted and fed to the SVM classifier. The proposed method was evaluated with three datasets containing 229 images. It achieved the accuracy of 90%, sensitivity of 86.33% and specificity of 98.55% with the average computational time 8 seconds per image. The method is simple and fast, easy to implement and the result is promising.
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A comparative study based on classical and newer piezoelectric materials based unimorph actuators for Hard Disk Drive
(2017-02-08)
Wattananukulchai, Parinya
;
Isarakorn, Don
The piezoelectric actuator technology for moving the read-write head of Hard Disk Drive (HDD) is very important and widely used. Advanced high-performance technologies for the actuator and servo control are required in order to achieve not only accurate positioning control on data tracks but also high-speed access onto another data track. There is strong demand for hard disk drives with high-speed access performance, which generally requires actuators with a wider servo bandwidth. This paper focuses on the comparative piezoelectric materials based unimorph actuators with classical piezo (Poly crystalline PZT) and newer piezo (Single-crystalline PMN-PT) ceramics. The advantages of piezoelectric materials in terms of mechanical and electrical characteristics aiming at a useful compromise performance displacement and resonant frequency are studied and analyzed.
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Automatic microaneurysms detection through retinal color image analysis
(2013-01-01)
Yunuch, Preeyaporn
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Maneerat, Noppadol
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Isarakorn, Don
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Pasaya, Bundit
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Panjaphongse, Ronakorn
This paper proposes an automatic system to diagnose the diabetic retinopathy symptom, which can cause a loss of vision by analysis the abnormality in retinal image. Digital image processing system is developed for the retinal image analysis which helps ophthalmologists to identify diabetic patients. The retinal images derived from ophthalmologists are used to analysis by using HSV, area identification and eccentricity techniques to distinguish diabetic retinopathy symptoms from normal diabetic patients. First color bar is evaluated by using HSV method and then using the eccentricity technique with area of pixel to find out the abnormality of Microaneurysms (MAs). The accuracy result of experiment is around 93% when compares to the analysis of ophthalmologists. © 2013 IEEE.
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Potential of Piezoelectric Floor Tile for Harvesting Energy from Human Footsteps
(2021-01-01)
Thanach-Issarasak, Nicharas
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Jayasvasti, Subhawat
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Yingyong, Phonexai
;
Isarakorn, Don
Since the last decade, piezoelectric floor tile energy harvesters have been developed to convert wasted mechanical energy into usable electrical energy. Our team has also been developing and improving this kind of harvester, abbreviated as EHFT, for several years. One of the developmental problems was in reporting a realistic value of energy generated by EHFT because it depended heavily on many real-world factors. The objective of this study was to determine such realistic value by simulating those factors with a real-world traffic of 30 people entering a building. An EHFT together with proper electrical measurement devices were installed at the entrance of a building in King Mongkut's Institute of Technology, Thailand, and a group of 30 people were asked to step on it while entering the building. The value of the cumulative generated energy from the EHFT with those participants for a time duration of 600 s was found to be 450.26 mJ. This value was sufficiently high to constantly power a temperature sensor during a whole workday. Therefore, we are in the process of developing an automated Covid-19 detection station in which the temperature sensor will be powered by this EHFT.
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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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Feature extraction from retinal fundus image for early detection of diabetic retinopathy
(2013-12-01)
Sreng, Syna
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Takada, Jun Ichi
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Maneerat, Noppadol
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Isarakorn, Don
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Varakulsiripunth, Ruttikorn
Automated detection of lesions in retinal fundus image can be aid in the detection of diabetic retinopathy. Exudates are the early sign of diabetic retinopathy so the proper detection of these lesions is an essential task in an automatic retinal screening. On the research work leading to automatic analysis of exudate detection, the knowledge of Optic Disk (OD) location is very useful. An efficient algorithm is presented to detect the OD and exudate which are the most important features for early detection of diabetic retinopathy. From a retinal fundus image, the proposed method first preprocesses and estimates the histogram of retinal background, then filters out the bright pixels in intensity image. They include OD, and non-OD (exudates and noise). Next, an OD boundary is determined and eliminated after applying blob boundary measurement and morphological reconstruction. Finally, exudates are extracted by applying the maximum entropy thresholding to filter out the bright pixels from the green component of retinal image which OD region inside is eliminated. The proposed technique has been tested first on 100 images from hospital. Experimental results show that 93% and 89% of OD and exudate were detected correctly, respectively. © 2013 IEEE.
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Technique for measuring power across high resistive load of triboelectric energy harvester
(2021-07-01)
Jayasvasti, Subhawat
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Thainiramit, Panu
;
Yingyong, Phonexai
;
Isarakorn, Don
This paper proposed a more-accurate-than-conventional measurement technique for determining electrical power across exceptionally high-impedance of triboelectric energy harvester (TEH). The key idea of this proposed technique was to measure the voltage across an introduced, parallelly-connected resistor divider to the oscilloscope instead of the voltage across the harvester. An experiment was set up to verify the measurement accuracy performance of this technique against the ideal theoretical values. The maximum percentage error found was only 2.30%, while the conventional measurement technique could not be used to measure voltage across high impedance TEH at all because the readings were not accurate, i.e., the measurement error would be at least over 10%. Therefore, we concluded that this proposed technique should always be used instead of the conventional measurement technique for power measurement of any TEH. A suggestion that we would like to offer to researchers investigating or developing a TEH is that, in using our measurement technique, a good starting point for a load to probe resistance ratio is 1:10, a ratio that worked well for our TEH test bench that we developed.

Isarakorn, Don

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