Browsing by Author "Lin, Shir-Kuan"

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3D surface profile measurement of unsymmetrical microstructure using Fizeau interferometric microscope
(2013-04-01)
Yang, Shih-Wei
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Lin, Chern-Sheng
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Lin, Shir-Kuan
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電控工程研究所
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Institute of Electrical and Control Engineering
In this paper, an automatic optical inspection system for the 3D surface profile of an unsymmetrical microstructure using Fizeau interferometer was proposed. This non-contact optical inspection system is suitable for measuring the lens sag and 3D surface profile of symmetrical and unsymmetrical microlenses. Referring to the unsymmetrical microlenses as an example, the distribution of the interference fringes is partly dense and partly rare, and is completely different from the equally dense distribution of symmetrical microlenses. Thus, a novel algorithm is proposed to solve the above mentioned problem in this paper, namely, individually determining the darkest points of the dark fringes and the brightest points of the bright fringes, and fitting these discrete points as close curves through the Bezier curve theory. As the contour lines of an unsymmetrical microlens are obtained, the 3D surface profile of the unsymmetrical microlens can be plotted correspondingly. Furthermore, the proposed system has the following advantages due to its non-contact structure. This system is specifically designed for in-line measurements according to the rapid inspection speed; it has no need to coat a reflective layer on the inspected microstructure, thus avoiding damaging the surface structure of the sample. (C) 2012 Elsevier Ltd. All rights reserved.
A new two-DOF rotational optical image stabilizer
(2011-06-01)
Chao, Paul C-P
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Chen, Yu-Han
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Chiu, Chi-Wei
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Tsai, Meng-Yen
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Chang, Jyh-Yeong
This work proposes design, optimization and validation of a new two degree-of-freedom (DOF) rotational optical image stabilizer (OIS) that is suitable for installing into a mobile-phone-camera. This OIS differs from the previous designs since it stabilizes the lens holder directly by two-DOF translational mechanisms that are actuated by voice coil motors. The work can be divided into three main parts: (1) designs of mechanism and genetic algorithm (GA) optimization of magnetic field, (2) establishments of the dynamic model and equation of motions (EOM) of a dual-axis rotational structure, and (3) realizations of a sliding mode control (SMC) controller with fine performance. The dynamic of the dual-axis rotational OIS system has been analyzed and the EOM has been derived. Based on the Lagrange's method, the motions of the OIS have been modeled through considering kinetic energy and electromagnetic torques. In the last part, the theory of SMC is applied, and the associated simulations are conducted. Based on the simulation results, the SMC controller is forged with the assistances from MATLAB pre-simulation and tested by a microprocessor module. After a series of experiments and verifications, the prototype of the novel OIS is finally accomplished with satisfactory performance of vibration reduction.
A Novel Readout Circuit for an OTFD Gas Sensor with a New Front-end Trans-impedance Amplifier
(2011)
Lin, Wan-Jun
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Chao, Paul C. -P.
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Lin, Shir-Kuan
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Zan, Hsiao-Wen
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電機工程學系
The study proposes a new readout circuit for an organic gas sensor. The readout circuit consists of a preamplifier, a sample and hold circuit and a differential current amplifier. A preamplifier composed of trans-impedance to convert the output current of a gas sensor into voltage. The sample and hold circuit memorizes various voltages according to distinct designed time instants in a target gas environment. At the same time it is equipped with the advantage of repeated detections by the controlling signals which determine the frequency of switch. The differential current is amplified by a differential current amplifier and is attributable to the voltages of sample and hold circuits using current mirror framework. Flowing through the resistance load, the differential current is converted into output voltage. A microprocessor control unit (MCU) acquires and stores the outputs in order to determine gas concentration database of pre-measured which are contrast. The designed circuit is accomplished by Taiwan Semiconductor Manufacturing Company (TSMC) 0.35 mu m 2P4M 3.3V mixed-signal CMOS process.
A novel twelve-step sensorless drive scheme for a brushless DC motor
(2007-06-01)
Wang, Chao-Min
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Wang, Shyh-Jier
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Lin, Shir-Kuan
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Lin, Hsing-Yu
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電控工程研究所
This paper presents a novel twelve-step sensorless drive scheme for a three-phase brushless DC motor, which combines the traditional six-step 120 degrees and 180 degrees conduction modes and has varied active angular period. The proposed scheme is implemented on a single FPGA-chip. Several experiments for various active angle periods from 124 degrees to 168.75 degrees are undertaken. The experimental results show that the torque constant is larger for the larger active angular period.
A Simple Single Shunt Current Reconstruction Approach for Low-Cost Permanent Magnet Synchronous Motor Drives
(2015)
Wang, Chao-Min
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Lin, Shir-Kuan
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電控工程研究所
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Institute of Electrical and Control Engineering
This paper presents a simple single-shunt current reconstruction approach in the direct current link (DC-link) for a three-phase voltage source inverter. A space vector pulse width modulation (SVPWM) technique with an adjusting scheme for switching states is investigated. Since three-phase input currents cannot be reconstructed in the unmeasurable area, a unified method for modifying the switching state of the pulse width modulation (PWM) rectifier is proposed. The proposed method can maintain the symmetrical double-sided modulation without changing the total duty cycle of the voltage vector, and the reconstructed three-phase currents approximate the currents measured from the traditional three-shunt sensing circuit. The comparison between a conventional SVPWM technique with adjusting scheme and the proposed approach is demonstrated. Significant simulation results for performance comparison and experimental verification of the current reconstruction scheme show that the proposed method can offer lower current distortion. Hardware implementation is carried out on the basis of an electric fan composed of a three-phase permanent magnet synchronous motor (PMSM) drive system by using a single DC current sensor and an embedded microsystem.
An automatic optical inspection system for measuring a microlens array with an optical interferometric microscope and genetic algorithm
(2013)
Yang, Shih-Wei
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Lin, Chern-Sheng
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Lin, Shir-Kuan
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Fu, Shu-Hsien
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Yeh, Mau-Shiun
Purpose - The purpose of this paper is to propose an automatic optical inspection system for measuring the surface profile of a microlens array. Design/methodology/approach - The system set-up was constructed according to the principle of the Fizeau interferometer. After capturing the ring interference fringe images of the microlens with a camera, the diameter, profile information and optical properties were analyzed through a microlens surface profile algorithm using innovative image pre-processing with a precision of less than 0.09 micron. Findings - By integrating with the genetic algorithm, the XY-Table shortest moving path of the system is calculated to achieve the purpose of highspeed inspection and automatic microlens array surface profile measurement. Originality/value - The measurement results of this system were also compared with other systems, including the atomic force microscope and stylus profiler, to verify the measurement precision and accuracy of this system.
Automatic defect recognition of TFT array process using gray level co-occurrence matrix
(2014)
Yang, Shih-Wei
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Lin, Chern-Sheng
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Lin, Shir-Kuan
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Chiang, Hsien-Te
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電控工程研究所
This study proposed an automatic optical inspection (AOI) system for detection of thin-film transistor (TFT) array defects. gray level co-occurrence matrix (GLCM) and MATLAB regionprops function were used to calculate 53 TFT array defect features, which were inputted into the neural network to train the defect classifier. The images to be inspected were compared with a standard image first, in order to judge whether the TFT array samples have defects. For defective images of a TFT array, the proposed defect classifier can successfully recognize five kinds of defects in the process. According to the experimental results, the defect recognition rate of proposed system is verified to be 83.3%, which can replace manual inspection and reduce the risks of false inspections due to long duration manual work. Moreover, the proposed AOI system can improve testing efficiency and reduce manufacturing costs. (C) 2014 Elsevier GmbH. All rights reserved.
AUTOMATIC INSPECTION SYSTEM FOR DEFECTS OF PRINTED ART TILE BASED ON TEXTURE FEATURE ANALYSIS
(2014-01-02)
Yang, Shih-Wei
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Lin, Chern-Sheng
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Lin, Shir-Kuan
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Tseng, Yung-Chin
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電控工程研究所
An automatic inspection system of printed art tile defects is reported in this artucke. After calculating eight defect features of art tile using the gray level co-occurrence matrix and the average R, G, B values of a defective area, the results were input into a backward propagation neural network for training the defect classifier. During inspection, the proposed system compared the inspected image with a standard image and removed noise by an erosion operation in order to preliminarily determine whether the art tile had defects. For the defective art tile images, the proposed classifier successfully identified four types of common printing defects. The proposed algorithm had an average recognition rate of 90%, suggesting that the recognition accuracy is good, and only requires 1-2s to inspect an art tile with the size of 15x15cm(2). The inspection speed is faster than the conventional manual inspection, and recognition results are more stable. The proposed system can reduce the risk of error caused by the long duration of manual inspection, and thus, can reduce manufacturing costs.
Automatic optical inspection system for 3D surface profile measurement of multi-microlenses using the optimal inspection path
(2014-07-01)
Yang, Shih-Wei
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Lin, Shir-Kuan
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電控工程研究所
;
Institute of Electrical and Control Engineering
In this paper, an automatic optical inspection system is proposed for measuring the three-dimensional surface profile of multi-microlenses according to the optimal inspection path. The proposed system is applicable for full and sampling inspection of microlens arrays, and has the following contributions: (1) the optimal inspection path of sampling inspection is derived by a Genetic Algorithm considering the acceleration characteristic of the XY-table. (2) The incomplete microlens fringe is removed, and the center of each microlens can be automatically positioned. (3) The phase difference of each neighboring pixel is calculated through the concept of sign reversal in order to rebuild the surface profile. According to the experimental results, the lens sag of microlenses in different sizes can be correctly measured by the proposed system, and a relative error of 3.4% (max) can be achieved. Compared with other methods, the positioning time of the proposed method is shortened by 10% to 30%, validating the practicability of this system.
Automatic optical inspection system for 3D surface profile measurement of multi-microlenses using the optimal inspection path
(2014-07-01)
Yang, Shih-Wei
;
Lin, Shir-Kuan
;
電控工程研究所
;
Institute of Electrical and Control Engineering
In this paper, an automatic optical inspection system is proposed for measuring the three-dimensional surface profile of multi-microlenses according to the optimal inspection path. The proposed system is applicable for full and sampling inspection of microlens arrays, and has the following contributions: (1) the optimal inspection path of sampling inspection is derived by a Genetic Algorithm considering the acceleration characteristic of the XY-table. (2) The incomplete microlens fringe is removed, and the center of each microlens can be automatically positioned. (3) The phase difference of each neighboring pixel is calculated through the concept of sign reversal in order to rebuild the surface profile. According to the experimental results, the lens sag of microlenses in different sizes can be correctly measured by the proposed system, and a relative error of 3.4% (max) can be achieved. Compared with other methods, the positioning time of the proposed method is shortened by 10% to 30%, validating the practicability of this system.
Design and implementation of antihandshaking position control for a voice coil motor
(2008-04-01)
Lin, Shir-Kuan
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Wang, Chao-Min
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Wang, Shyh-Jier
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電控工程研究所
;
Institute of Electrical and Control Engineering
This paper deals with the position control of the voice coil motor (VCM) with handshaking. A disturbance observer is proposed to estimate the low-frequency handshaking disturbance, so that a handshaking-robust controller can be constructed. While a handshaking stabilizer can compensate for the vibration of the whole lens set, a robust controller is still required to precisely hold the autofocusing lens by rejecting the handshaking disturbance. To meet the request of miniaturization, the control is implemented on a field programmable gate array chip. (C) 2008 American Institute of Physics.
DESIGN OF AN AUTOMATED FEEDBACK CONTROL COOLING SYSTEM FOR SWIR LINEAR IMAGE SENSOR APPLICATION
(2010)
Chen, Chien-Hung
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Chen, Chih-Wen
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Lin, Chun-Fu
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Liao, Tai-Shan
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Hwang, Chi-Hung
Our novel automated feedback temperature controlled cooling system consists of a temperature measurement circuit, a TE cooler, a thermistor, a microcontroller, and a digital-to-analog converter and PWM algorithms. The measurement accuracy of this temperature controlled TE system was better than 0.1 degrees C and can be used for maintaining an instrument's isothermal applications. The experimental results of SWIR linear image shows that the temperature can be stably maintained at -20 degrees C, the dark output current can be reduced almost 80mV (Integration time: 100 ms) and the SNR of pixel can be improved from 48dB to 83dB as well.
Design of an automatic shift control system with self-learning ability for a bicycle
(2015-07-01)
Lin, Shir-Kuan
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Yang, Shih-Wei
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Cheng, Chi-Chang
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電控工程研究所
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Institute of Electrical and Control Engineering
An automatic shift control system with self-learning ability, for a bicycle is proposed in this paper. The concept of pseudo pedaling speed is used as the shifting basis, and the pseudo pedaling speed is derived from the wheel speed read through a microcontroller. According to the pseudo pedaling speed histograms, all riders\' pseudo pedaling speed histograms approach normal distribution. Hence, a straight forward algorithm of shifting using the mean and standard deviation of the riders\' pseudo pedaling speed is developed. The microcontroller commands the actuators to shift up or shift down a gear with the proposed algorithm. According to the experimental results, the proposed system has been shown to function well, thus, enhancing the convenience and comfort of cycling.
Design of virtual keyboard using blink control method for the severely disabled
(2013-08-01)
Yang, Shih-Wei
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Lin, Chern-Sheng
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Lin, Shir-Kuan
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Lee, Chi-Hung
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電控工程研究所
In this paper, a human-machine interface with the concept of "blink control" is proposed. The human-machine interface is applied to an assistive device, namely "blink scanning keyboard", which is designed specifically for the severely physical disabled and people suffering from motor neuron diseases or severe cerebral palsy. The pseudo electromyography (EMG) signal of blinking eyes could be acquired by wearing a Bluetooth headset with one sensor on the forehead and the other three on the left ear of the user. Through a conscious blink, a clear and immediate variation will be formed in the pseudo EMG signal from the users' forehead. The occurrence of this variation in pseudo EMG signal could be detected and filtered by the algorithms proposed in this paper, acting like a trigger to activate the functions integrated in the scanning keyboard. The severely physical and visual disabled then can operate the proposed design by simply blinking their eyes, thus communicating with outside world. (C) 2013 Elsevier Ireland Ltd. All rights reserved.
Dual-Radiation Pattern RFID Tag Design For Application In Library Management
(2015)
Chiou, Shin-Fu
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Lin, Shir-Kuan
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Chen, Sung-Lin
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電控工程研究所
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Institute of Electrical and Control Engineering
Recently, Radio frequency identification (RFID) has been applied widely, but still have some problems in the library searching system. The challenge of RFID searching system is it can only point out the approximate area, but not the location even if where the side of the bookcase is. This paper is proposing a new method and antenna structure by providing two omni-directions which narrow down the searching area and recognize the book\'s location on the bookcase. The proposed is a dual-radiation pattern of RFID tag. It is a two-port structure and combined with two RFID chips and a pair of Yagi-Uda. Two different radiation patterns are created, which will recognize whether the target is in front of the searcher or is in the opposite side to help locating. This tag can direct the searcher and locate the target more precisely than before. After several rounds of test validation and modification, the design provides a rapid searching mechanism. The structure of this antenna is simple and very flexible for users, it becomes a new solution for searching system in the future.
Fall detection for multiple pedestrians using depth image processing technique
(2014-04-01)
Yang, Shih-Wei
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Lin, Shir-Kuan
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電控工程研究所
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Institute of Electrical and Control Engineering
A fall detection method based on depth image analysis is proposed in this paper. As different from the conventional methods, if the pedestrians are partially overlapped or partially occluded, the proposed method is still able to detect fall events and has the following advantages: (1) single or multiple pedestrian detection; (2) recognition of human and non-human objects; (3) compensation for illumination, which is applicable in scenarios using indoor light sources of different colors; (4) using the central line of a human silhouette to obtain the pedestrian tilt angle; and (5) avoiding misrecognition of a squat or stoop as a fall. According to the experimental results, the precision of the proposed fall detection method is 94.31% and the recall is 85.57%. The proposed method is verified to be robust and specifically suitable for applying in family homes, corridors and other public places. (C) 2014 Elsevier Ireland Ltd. All rights reserved.
Fast regulation of the rolling sphere: A motion planning approach
(2007)
Lee, Ti-Chung
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Lin, Shir-Kuan
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電控工程研究所
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Institute of Electrical and Control Engineering
This paper presents a simple stabilizing control scheme for the rolling sphere. A tracking control problem with respect to a "virtual moving trajectory" is first solved. Then, it is used to achieve practical stability for the regulation problem. The derived controllers have a simple form and can guarantee fast convergence. To verify the effectiveness of the proposed results, an interesting simulation result is presented.
Friction Compensation of a Mini Voice Coil Motor by Sliding Mode Control
(2009)
Tsai, Ching-Lung
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Lee, Ti-Chung
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Lin, Shir-Kuan
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電控工程研究所
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Institute of Electrical and Control Engineering
This paper presents a sliding mode controller to compensate the friction of mini voice-coil motor (VCM), embedded with guide pins, for position control in compact camera module (CCM) application. In the VCM, actuator full stroke is only 0.35mm or less, nonlinear friction force falls into mismatched condition and um-level resolution is required. With proposed controller, arbitrarily small steady state error can be approached by pole placement tithe sliding mode state equation. The performance is firstly simulated with a physical VCM model. The experimental result is then presented to demonstrate the proposed controller is able to avoid stick-slip oscillation that usually yields when using classic controller, such as PI controller.
Inverting level-shift circuit has negative potential
(2012-07-01)
Lin, Chun-Fu
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Lin, Shir-Kuan
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Huang, Hui-Shun
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Chang, Jyi-Jinn
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Liao, Tai-Shan
Lens sag and diameter measurement of large-size microlenses using sub-pixel algorithm and optical interferometry
(2014-04-01)
Lin, Shir-Kuan
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Yang, Shih-Wei
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電控工程研究所
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Institute of Electrical and Control Engineering
In this paper, an automatic optical inspection system is designed specifically to measure the diameter and lens sag of large-size microlenses: 1. The proposed algorithm of measuring lens diameter locates the lens center through the Euclidean distance array, and determines the lens edge along an initiated ray using linear interpolation with sub-pixel accuracy. 2. The lens sag is calculated from a single fringe pattern of large-size microlens, in combination with the measured lens diameter. 3. According to the experiment results, the proposed system has advantages of high applicability, rapid processing speed, and good accuracy with the RMS error <=% of measuring a large-size microlens, but without the requirement of prior training. The system architecture of non-contact measurement would not cause scratches on the lens surface and is inexpensive, this, which is particularly suitable for the in-line inspection of industry field. (C) 2013 Elsevier Ltd. All rights reserved.