• JSTS:Journal of Semiconductor Technology and Science
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• v.7 no.3
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• pp.151-160
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• 2007

We report the label-free biomolecules detection based on nanomechanical micro cantilevers operated in dynamic mode for detection of two marker proteins (myoglobin and creatin kinase-MB (CK-MB)) of acute myocardical infarctions. When the specific binding between the antigen and its antibody occurred on the fuctionalized microcantilever surface, mechanical response (i.e. resonant frequency) of microcantilevers was changed in lower frequency range. We performed the label-free biomolecules detection of myoglobin and CK-MB antigen in the low concentration (clinical threshold concentration range) as much as 1 ng/ml from measuring the dynamic response change of micro cantilevers caused by the intermolecular force. Moreover, we estimate the surface stress on the dynamic microcantilevers generated by specific antibody-antigen binding. It is suggested that our dynamic microcantilevers may enable one to use the sensitive label-free biomolecules detection for application to the disease diagnosis system based on mechanical immuno-sensor.

• Journal of the Korean Society of Safety
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• v.16 no.4
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• pp.200-207
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• 2001

The transmission of harmonic vibratory power form a vibrating rigid body into a supporting plate through passive and active isolators is investigated theoretically and experimentally. The theoretical model allows for the transmission of vertical and horizontal harmonic forces and moments about all three coordinate sun. The experiment is to use vibration actuators attached to the intermediate mass of the two-stage mount to minimize the rotational and translational vibration of the intermediate mass. The performance is done by measuring the vibration at the error sensors due to the primary vibration source and measuring the transfer functions from the control sources to the error sensors. Results show that over a frequence range from 1 to 100Hz, transmission into the supporting plate can be reduced substantially by employing in parallel with existing passive isolators, active isolators adjusted to provide appropriate control force amplitudes.

• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.1
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• pp.106-113
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• 2009

This paper presents a surface acoustic wave(SAW) micro-electro-mechanical-systems(MEMS) interdigital transducer (IDT) gyroscope with 80MHz central frequency on a $128^{\circ}\;YX\;LiNbO_3$, which is consisted of a two-port SAW resonator, metallic dots and dual delay lines for the sensor and reference oscillators. Reason for using two delay line oscillators is to extract the gyroscope effect by comparing the resonant frequencies between two oscillators and to compensate the temperature effect. Based on the coupling of modes(COM) simulation, an 80MHz two ports SAW resonator and dual delay line were fabricated and characterized by the network analyzer. Obtained sensitivity was $109Hz/deg{\cdot}s^{-1}$ in the angular rate range of $0{\sim}1000deg/s$. Good Linearity and superior directivity were observed.

• Journal of Power Electronics
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• v.14 no.5
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• pp.957-966
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• 2014

Some of DC actuators used in home automation, office automation, medical equipment and automotive systems require a position sensor. In low power applications, the introduction of such a transducer remarkably increases the whole system cost, which justifies the development of sensorless position estimation techniques. The well-known AC motor drive sensorless techniques exploiting the fundamental component of the back electromotive force cannot be used on DC motor drives. In addition, the sophisticated approaches based on current or voltage signal injection cannot be used. Therefore, an effective and inexpensive sensorless position estimation technique suitable for DC motors is presented in this paper. This technique exploits the periodic pulses of the armature current caused by commutation. It is based on a simple pulse counting algorithm, suitable for coping with the rather large variability of the pulse frequency and it leads to the realization of a sensorless position control system for low cost, medium performance systems, like those in the field of automotive applications.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.6
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• pp.988-994
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• 1997

The demands for robotic and automatic system are continually increasing in manufacturing fields. There have been many studies to monitor and predict the system, but they have mainly focused upon measuring cutting force, and current of motor spindle, and upon using acoustic sensor, etc. In this study, digital image of time series sequence was acquired by taking advantage of optical technique. Mean square error was obtained from it and was available for useful observation data. The parameter was estimated using PAA(parameter adaptation algorithm) from observation data. AR(auto regressive) model was selected for system model and fifth order was decided according to parameter estimation. Uncorrelation test was also carried out to verify convergence of parameter. Through the proceedings, it was found that there was a system stability.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.2
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• pp.1-6
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• 2008

In recent years, developments in the semiconductor and electronic industries have brought a rapid increase in the use of large size silicon wafer. For further improvement of the ultra precision surface and flatness of Si wafer necessary to high density ULSI, it is known that polishing is very important. However, most of these investigation was experiment less than 300mm diameter. Polishing is one of the important methods in manufacturing of Si wafers and in thinning of completed device wafers. This study reports the machining variables that has major influence on the characteristic of wafer polishing. It was adapted to polishing pressure, machining speed, and the slurry mix ratio, the optimum condition is selected by ultra precision wafer polishing using load cell and infrared temperature sensor. The optimum machining condition is selected a result data that use a pressure and table speed data. By using optimum condition, it achieves a ultra precision mirror like surface.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.3
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• pp.275-284
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• 2012

This paper proposes an attitude and direction control of a single wheel balanced robot. A unicycle robot is controlled by two independent control laws: the mobile inverted pendulum control method for pitch axis and the reaction wheel pendulum control method for roll axis. It is assumed that both roll dynamics and pitch dynamics are decoupled. Therefore the roll and pitch dynamics are obtained independently considering the interaction as disturbances to each other. Each control law is implemented by a controller separately. The unicycle robot has two DC motors to drive the disk for roll and to drive the wheel for pitch. Since there is no force to change the yaw direction, the present paper proposes a method for changing the yaw direction. The angle data are obtained by a fusion of a gyro sensor and an accelerometer. Experimental results show the performance of the controller and verify the effectiveness of the proposed control algorithm.

• Journal of Magnetics
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• v.21 no.2
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• pp.173-178
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• 2016

Six-step commutation control widely used in brushless DC (BLDC) motor can be applied to consequent pole permanent magnet (CPPM) belt starter generator (BSG) with trapezoidal back electromotive force (EMF) in the starter state. However, rotor position detection with three Hall sensors in BLDC motor can hardly be employed in CPPM BSG due to asymmetric flux distribution in each pole side of CPPM BSG. This paper presents a low-cost rotor position detection method for CPPM BSG in which six Hall sensors are proposed to be used based on the analysis of flux distribution by 3D FEA. In the method, the six Hall sensors are divided into three groups and two signals in each group are combined through performing logic operations. In addition, offset angle between back EMF and the related Hall signal can be compensated by moving the Hall sensors. Experiments of a 2 kW CPPM BSG prototype have also been performed to verify the proposed method.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.10 no.3
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• pp.229-236
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• 2016

Magnetic sensors and actuators have been widely used in industry and medical fields. Integrated systems based on sensors and actuators are defined as mechatronics that is the general combination of mechanics and electronics. Recently, magnetic wireless sensors and actuators have been developed and used at a systematic level. In particular, their mechanisms depend on magnetic, such as magnetic material and physical phenomena. However, their research boundary has not been clear. Researchers talk of magnetic micro-robots, magnetic actuators and sensors. Therefore, a new and correct definition is required. In this study, we introduce the advanced and extended concept of mechatronics, which is a magneto-mechantronics for biomedical and rehabilitation. Among various applications, we focused on wireless pump and sensing system for blood vessel rehabilitation and local motion capture, respectively.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.5
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• pp.219-225
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• 2003

This paper described about the acoustic wave measurement method to diagnose GIS for particles. We measured and analyzed the signals of acoustic waves with two type acoustic sensors having 125kHz and 50kHz resonant frequency respectively when the particles were bounced on the inside surfaces of GIS tanks by the electrostatic force. To use two sensors for the diagnosis of GIS, we set up the calibration method for this measurement method. We showed the output characteristics of two sensors according to the sizes and materials of particles in the experiment. As the results, the inception voltages bouncing particles depended on the materials and the extinction voltages bouncing them depended on the sizes and materials. We found out that the relationship between sizes of particles and output voltages of sensors didn't have linearity but the ratios of between peak values of two sensors depended on the materials of GIS enclosures and the sizes of particles.