• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.87-90
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• 2005

An experimental investigation of the basic characteristics of a micro-cantilever sensor was performed by inspecting the amplitude and frequency characteristics using a commercial tuning fork. Application of acetone and ethanol with a volume of $1 {\mu}l$ on the tine of a vibrating tuning fork cause immediate response in its amplitude and frequency. It has shown that the tuning fork has ability to recognize a chemical agent with high sensitivity.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.5
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• pp.35-40
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• 2005

An experimental Investigation of the basic characteristics of a micro-cantilever sensor was performed by inspecting the amplitude and frequency characteristics of a commercial tuning fork (TF). Application of acetone and ethanol with a volume of $1{\mu}l$ on the tine of a vibrating tuning fork causes immediate response in its amplitude and frequency characteristics. It has been shown that the tuning fork has ability to recognize a chemical agent with high sensitivity. The theoretical sensitivity of mass loading is in the range of $\~0.1Hz/ng$. Quartz tuning forks are routinely made using standard microfabrication process, thus suggesting the possibility of microfabrication of micro quart sensors.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.1
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• pp.86-91
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• 2007

A sensor using quartz toning fork is presented for measuring liquid density. It consists of a PZT plate as an actuator for piezoelectric excitation and a quartz tuning fork as a sensor for resonant frequency detection. The resonant frequency is determined from the sensing voltage measured in tuning fork when the excitation frequencies of PZT actuator are swept around the resonant frequencies of tuning fork. The resonant frequency determined the liquid density. The density values of three kinds of organic solvents are measured and compared with the standard values. The experimental results are in agreement with the standard values and the maximum standard deviation is less than 9%.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.480-483
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• 2003

This paper deals with speed control of Sensorless DC servo motor using a FTHGO(FuzEy-Tuning High Gain observer). In this paper, we improved the problem from row speed section, the problem of sensor for detecting speed of motor, using FTHGO(Fuzzy-Tuning High-Gain Observer) with fuzzy control technique which is a class of adaptive control technique. In order to verify the performance of the FTHGO(Fuzzy-Tuning High Gain Observer) which is proposed in this paper, it is proved from the experiment to compare the case with a speed sensor to the case with FTHGO(Fuzzy-Tuning High Gain observer) in the speed control of DC servo motor.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.1
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• pp.136-142
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• 1995

An analysis model is proposed for the performance prediction of typical ball and tube type mechanical crash sensors based upon mass-spring-viscous gas damping idealization. Also a construction of mechanical crash pulse generator is suggested as an experimental tool for calibration and verification of model predictions. A sensor tuning procedure for a particular set of crash pulses is suggested based upon the analysis model and the experimental tools.

• Journal of Biosystems Engineering
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• v.33 no.1
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• pp.58-62
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• 2008

The need for position information in agriculture is gradually increasing for precise control farm vehicle and effective manage farm land. Though geomagnetic sensor has a lot of merits in estimating heading angle of vehicle because of low costs and sensing ability of magnetic north, it is easy that sensor outputs are distorted in electro magnetic field environment. This study was conducted to develop geomagnetic compass which could be available in measuring relative position from reference point correcting output distorted by external electro magnetic field in a small scale field. Magnetic inducing sensor (PNI's Vector2X) which wound enamel coated copper coil on ferrite core in order to measure and correct earth magnetic field. Magnetic azimuth was corrected using the algorithm which estimated amount of magnetic distortion from the difference between each outputs of magnetic sensors that located on the cross shaped base. Developed auto-tuning magnetic sensor was showed less then 5% as bearing accuracy in the strong magnetic field.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.628-631
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• 2005

In this paper, we propose tuning method of PID-PD controller to satisfy design specifications in frequency domain as well as time domain. The proposed tuning method of PID-PD controller that consist of the convex set of PID and PI-PD controller controls the closed-loop response to locate between the step responses, and Bode magnitudes of closed-loop transfer functions controlled by PID and PI-PD controller. The controller is designed by the optimum tuning method to minimize the proposed specific cost function subject to sensor noise insensitivity and robust stability. Its effectiveness is examined by the case study and analysis.

• Smart Structures and Systems
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• v.12 no.1
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• pp.23-39
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• 2013

In this article, a smart multifunctional optical system-on-a-chip (SOC) sensor platform is presented and its application for fiber Bragg grating (FBG) sensor interrogation in optical sensor networks is investigated. The smart SOC sensor platform consists of a superluminescent diode as a broadband source, a tunable microelectromechanical system (MEMS) based Fabry-P$\acute{e}$rot filter, photodetectors, and an integrated microcontroller for data acquisition, processing, and communication. Integrated with a wireless sensor network (WSN) module in a compact package, a smart optical sensor node is developed. The smart multifunctional sensor platform has the capability of interrogating different types of optical fiber sensors, including Fabry-P$\acute{e}$rot sensors and Bragg grating sensors. As a case study, the smart optical sensor platform is demonstrated to interrogate multiplexed FBG strain sensors. A time domain signal processing method is used to obtain the Bragg wavelength shift of two FBG strain sensors through sweeping the MEMS tunable Fabry-P$\acute{e}$rot filter. A tuning range of 46 nm and a tuning speed of 10 Hz are achieved. The smart optical sensor platform will open doors to many applications that require high performance optical WSNs.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.156-160
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• 1996

A vibrating angular rate sensor with tuning fork type resonator of microstructure (940*820 .mu. m$^{2}$) was designed and will be fabricated by polysilicon surface micromaching. The angular rate sensor is driven in a lateral direction by electrostatic force of comb drive electrodes, and vertical vibrations of the sensor, thich is detected capacitively, are produced by Coriolis forces due to an external angular rate. Mechanical Q factors and a difference between the frequencies of the two resonant modes, the driving mode and detecting mode, play a great role in increasing the sensitivity of the sensor. To be a highly sensitive sensor, it was designed to have as small frequency discrepancy of the two resonant modes as possible. Finite element method was used for the modal analysis. Several design parameters were selected and their contributions to the modal frequencies were investigated. A method was presented for tuning the detecting mode frequency by DC bias on the drive electrodes.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.3
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• pp.244-249
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• 2008

This paper deals with speed control of DC servo motor using a Fuzzy tuning observer. Speed sensor detect a speed of rotor continuously. But it have a limit as a driving speed to detect speed precisely. So it is problem to improve the performance of the driving system. To solve the problem, it is studied to detect a speed of DC motor without sensor. In particular, study on the method to estimate the speed using the observer is performed a lot. In this parer, the gain of the observer is properly set up using the fuzzy observer. The fuzzy observer has a superior transient characteristic and is easy to implement compared the existing method is designed. It estimate the derivative of the armature current directly using the armature current measured in the DC motor. It estimate the speed of the rotor using the differentiation. It is proposed speed sensorless control method using the estimated speed. Optimal gain of Luenberger observer is set up using the fuzzy observer and adapted speed control of DC servo motor low speed operation. It is proved excellence and feasibility of the presented observer from the comparison tested a case with a speed sensor and a case without a speed sensor which used a highly efficient drive and 200W DC servo motor starting system.