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Energy saving of three-phase induction motor using fuzzy controller
(2006-12-01)
Tipsuwanporn, V.
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Intajag, S.
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Harnnarong, S.
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Krongratana, V.
This paper presents energy saving of three-phase induction motor, which is operated in regenerative mode. In this mode, the energy flows back into DC link voltage and causes to occur high voltage in capacitor that may be destroy the capacitor and switching component such an IGBT. The proposed method presents connection buck converter circuit between the rectifier diodes and the inverter, to control the voltage feeding into the inverter by using two fuzzy controllers. The first fuzzy controller will be managing the switching duty cycle of buck converter. The second fuzzy controller, which provide to control the switching component of braking circuit. The second controller will be synchronized with the first controller to balance the energy of the capacitor. © 2006 ICASE.
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8-channel reading of analog to digital converter
(2006-12-01)
Intajag, S.
;
Samaimak, S.
In data acquisition, the method to read data has an effect to the access time and more importance with the accuracy and precision of the data. In this paper, 8-channel reading is proposed by using LTC1298, which is a chip to convert analog to digital signal. In our scheme, the eight chips are employed to construct the 8-channel of analog to digital conversion. Our scheme can read all 8 channels at the same time. © 2006 ICASE.
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Iterative satellite image segmentation by fuzzy hit-or-miss and homogeneity index
(2006-04-01)
Intajag, S.
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Paithoonwatanakij, K.
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Cracknell, A. P.
Object-based segmentation is the first essential step for image processing applications. Recently, satellite image segmentation techniques have been developed, but not enough to preserve the significant information contained in the small regions of an image. The proposed method is to partition the image into homogeneous regions by using a fuzzy hit-or-miss operator with an inherent spatial transformation, which enables the preservation of the small regions. In the algorithm proposed here, an iterative segmentation technique is formulated as consequential processes. Then, each time in iterating, hypothesis testing is used to evaluate the quality of the segmented regions with a homogeneity index. The segmentation algorithm is unsupervised and employs few parameters, most of which can be calculated from the input data. This comparative study indicates that the new iterative segmentation algorithm provides acceptable results as seen in the tested examples of synthetics and satellite images.
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Automatic image segmentation using fuzzy hit or miss and homogeneity index
(2006-01-10)
Intajag, S.
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Paithoonwatanakij, K.
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Cracknell, A. P.
This paper proposes an automatic image segmentation algorithm. Our hierarchical algorithm uses recursive segmentation that consists of two major steps. First, local thresholding is carried out by the fuzzy hit-or-miss operator, which allows dynamic separation of a grey-scale image into two classes, based on local intensity distributions. The fuzzy hit-or-miss, being an operator of fuzzy mathematical morphology, plays an important role in performing the dynamic local segmentation. This operator gives a better shape description than global thresholding methods. It also retains small but significant regions in satellite images. Second, the homogeneity index is measured in each class based on the quality of normalized intra-region uniformity. The proposed method has been tested using both synthetic and satellite images successfully; moreover, the algorithm can estimate the number of classes automatically. © 2006 Taylor & Francis.
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Speckle noise reduction using adaptive singular value decomposition in logarithmic domain
(2005-12-01)
Chitwong, S.
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Thongsila, A.
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Intajag, S.
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Nilas, P.
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Cheevasuvit, F.
This paper presents applying the singular value decomposition to reduce speckle noise. Generally, it is used to filter the additive Gaussian noise with zero mean and any variance. Since speckle noise is in multiplicative model, to transform multiplicative model into additive model, we then employ logarithmic transformation. In this paper, speckle noise is generally modeled as Gamma distribution function corresponding with speckle noise of synthetic aperture radar (SAR) imagery applied. All singular value decomposition based filtering processing is in logarithmic domain. Threshold value to determine the effective rank and orders of matrix are adapted as homogeneity analysis. The orders of matrix are consisted of 16 by 16, 8 by 8 and 4 by 4. Normally, the results of the singular value decomposition based filtering after that the filtered matrix is transformed into spatial domain by exponential function is in block-fashion, then blocking effect is occurred. To smooth, the filtered matrix is performed as average filtering by using a number of pixels of 4 by 4 pixels around center of one. Experiments are tested using both simulated image and real image. Signal to noise ratio and equivalent number of looks are employed to evaluate the performance of our method. Our results are good enough when compared with the recent results at which such method is more complex. © 2005 by the American Society for Photogrammetry and Remote Sensing.
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Source Identification of Electromagnetic Radiation in Electronic Circuits Using Artificial Neural Network
(2005-01-01)
Aunchaleevarapan, K.
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Intajag, S.
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Khan-Ngern, W.
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Preampaneerach, Y.
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Teekaput, P.
The Artificial Neural Network (ANN) is applied to recognize different models of a dipole-like antenna and a loop-like antenna using its radiated emission patterns, which are radiated from the electronic circuits. The radiated patterns, which are detected through the monitoring of the amplitude emitting from the antenna-like structures, are used to train the ANN. The electronic circuits (source) have various configurations that provide the different patterns; however, the trained ANN can identify the configurations all of those structure-like antennae from the radiated emission pattern measurements.
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A robust control structure enhancing nominal model following scheme for induction servomotor drive
(2004-12-01)
Phanphairoje, S.
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Witheephanich, K.
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Piyarat, W.
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Intajag, S.
Motivated by the adaptive model following concept, a robust model following scheme Nominal Model Following Control (NMFC) is developed in this paper. NMFC has three main features: the use of a nominal model of the plant as a reference model, the introduction of a model controller which fulfills the reference tracking requirement and the inclusion of a simple PID correction mechanism which copes with all dynamic deviations of the real plant from its nominal model. Then, a simple robust controller are also designed and augmented with NMFC to reduce the effects of parameter variations and external disturbances further. The proposed control design techniques are employed to show the practicality of the technique for controlling induction servomotor system models. Simulation results illustrate that the desired tracking control performance of the servo drive can be preserved under wide operating range and good load regulating performance can also be obtained.
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Neuro-fuzzy controller design for industrial process controls
(2004-12-01)
Tipsuwanporn, V.
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Intajag, S.
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Witheephanich, K.
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Koetsam-ang, N.
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Samiamag, S.
In this paper, an industrial controller is designed with the neuro-fuzzy model based on Sugeno-type fuzzy inference. The designed controller is a nonlinear system, which uses the relation between input and output data. The fuzzy system is employed as the controller, which can be tuned itself by the neural network mechanism based on a gradient descent technique. The controller is implemented with M-file and graphic user interface (GUI) of Matlab program. The program uses MPIBM3 interface card to connect with the industrial processes. The proposed controller provides the online tunable mode to adjust the fuzzy rule bases with real time. In the experimentation, the proposed method is tested by varying of the process parameters, set points and load disturbance. Two processes, which consist of the level and temperature controls, are used to evaluate the efficiency of our controller. The results of the both processes are compared with two PID systems that are 3G25A-PIDO1-E and E5AK of OMRON. From the comparison results, our controller performance can be archived in the case of more robustness than the two PID systems.
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Adjustable frequency control using BRM for induction heating
(2004-12-01)
Tipsuwanporn, V.
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Intajag, S.
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Charean, A.
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Sawaengsinkasikit, W.
This paper proposes a method for controlling energy distribution to 1 phase induction heating coil by using the Binary Rate Modulation (BRM) Technique. Such method provides proper frequency to the heating coil's requirement by control the frequency at the resonance point, that is, 64-kHZ frequency band. System design are classified to 2 parts. The first part determines main frequency, and the second part generates the frequency from the 8-bit BRM derived from IC no. PAL22V10 in order to control the frequency for Full-bridge connected inverter when supplying the energy required by the 1 phase induction heating coil. Therefore, efficiency of the energy supply can be increate.
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Enhanced control design of single phase AC-DC converter using power balance calculator
(2004-12-01)
Tipsuwanporn, V.
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Intajag, S.
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Tarasantisuk, C.
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Tunyasrirut, S.
A single phase ac-dc converter with unity power factor (UPF) have been proposed in this paper. The hysteresis current control scheme is employed to track the line current command while the control signal of the four power switches are derived from the Power Balance Calculator (PBC) for achieving a fast response, high power factor during steady state operation with a constant load. The proposed control scheme and the circuit configuration can be applied to the three phase converter to eliminate the harmonic currents from the nonlinear load.
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