• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.12
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• pp.1185-1192
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• 2012

The typical operating temperature of an automotive fuel cell is lower than that of an internal combustion engine, which necessitates a refined strategy for thermal management. In particular, the performance of the cooling module has to be higher for a fuel cell system because the temperature difference between the fuel cell and the surrounding is lower than in the case of the internal combustion engine. Even though the cooling system of an automotive fuel cell determines the operating temperature and temperature distribution of the fuel cell, it has attracted little research attention. This study presents the mathematical model of a cooling system for an automotive fuel cell system using Matlab/$Simulink^{(R)}$. In particular, a radiator model is developed for design optimization from the development stage to the operating stage for an automotive fuel cell. The cooling system model comprises a fan, pump, and radiator. The pump and fan model have an empirical relation, and the dynamics of the pump and fan are only explained by motor dynamics. The basic design study was conducted, and the geometric setup of the radiator was investigated. When the control logic was applied, the pump senses the coolant inlet temperature and the fan senses the coolant out temperature. Additionally, the cooling module is integrated with the fuel cell system model so that the performance of the cooling module can be investigated under realistic operating conditions.

• Journal of the Institute of Convergence Signal Processing
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• v.21 no.1
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• pp.21-28
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• 2020

In this paper, a new type of electric wheelbarrow is proposed and developed. The developed electric wheelbarrow is equipped with an attitude reference system(ARS) sensor, which consists of 3-axis acceleration sensor and 2-axis Gyro sensor so that it can estimate pitch angle and roll angle. When an operator tilts the wheelbarrow up and down, the pitch angle is detected. The sign of the pitch angle is interpreted as the operator's intention for moving the wheelbarrow forward or backward and the controller drives the wheel of the wheelbarrow with the velocity according to the magnitude of the detected pitch angle. A cargo box of the wheelbarrow is designed to rotate and is controlled to maintain level always, so an operator can handle the electric wheelbarrow easily and safely. The wheelbarrow consists of an in-wheel motor, a DC motor, motor drives, an ARS sensor considering economical use in industrial field. Three experiments are performed to verify the feasibility and stability of the electric wheelbarrow.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.1
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• pp.17-22
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• 2016

A voice coil actuator with moving coil type for scanning mirror system of barcode reader has been developed. The actuator has a simple structure including a magnet, a coil and a pin. The performance of the actuator is analyzed by a linearized theoretical model. And the dynamic performance of the proposed actuator is predicted through motor constant and restoring constant obtained by finite element simulations. The theoretical model was verified by the prototype which has 64 Hz resonance frequency and 60 deg reflecting angle. We also discovered that that 3 V input can make the actuator rotate over 61.8 deg reflecting angle at 50 Hz resonance frequency. The proposed actuator can simplify its driving configuration because of its implementation of open-loop control.

• Journal of the Korean Society for Railway
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• v.13 no.2
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• pp.173-178
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• 2010

Electric railroad systems consist of supply system of electric power and electric locomotive. The electric locomotive is adapted to high speed driving and mass transportation due to obtaining high traction force. The electric locomotive is operated by motor blocks and traction motors. Train speed is controlled by suppling power from motor blocks to traction motors according to reference speed. Speed control of the electric locomotive is efficient by spending minimum energy between motor blocks and traction motors. Recently, induction motors have been used than DC and synchronized motors as traction motors. Speed control of induction motors are used by vector control techniques. In this paper, speed of the induction motor is controlled by using the vector control technique. Control system model is presented by using Simulink. Pulse is controlled by PI and hysteresis controller. IGBT inverter is used for real-time control and system performance is demonstrated by simulating the induction motor which has 210[kW] on the output power.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.12
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• pp.1529-1534
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• 2013

A voice coil actuator with a rotating moving magnet has been developed for a miniaturized mobile robot. The actuator has simple structure comprising a magnet, a coil, and a yoke. Actuator performance is predicted using a linearized theoretical model, and dynamic performance based on the air-gap between the magnet and the coil is predicted using motor constant and restoring constant obtained through finite element simulations. The theoretical model was verified using a prototype with 60 Hz resonance and 80 Hz bandwidth. We found that an input of 1.5 V can make the actuator rotate by $20^{\circ}$ statically. The driving configuration of the proposed actuator can be simplified because of its implementation of open-loop control.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.05a
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• pp.348-354
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• 1999

In recent years, a PID controller has been used as a major control method in real control processes. This controller requires a determination of PID control gains. But it is difficult to select the best gains theoretically. Thus there have been many approaches to determine them empirically Most of them are based on experience and knowledge. In this paper, we proposed a tuning method of the PID Parameters by using neural network. To show effectiveness of the proposed method, the simulation of DC motor and one link manipulator position control is carried out.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.840-842
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• 2001

The cogging torque and torque ripple in motor which cause noise and vibration are an inevitable phenomenon and they give a bad effect to motor performance. So we are required to reduce the cogging torque and torque ripple not by electrical controlling but by changing the inner mechanical structure and we focused on the permanent magnet. In this research, we calculated current, torque, Back-EMF(electromotive force) and cogging torque according to the change of the magnet shape using two dimensional FEM(Finite Element Method). Maxwell stress tensor and time-stepping method. From the results, we present an appropriate model that can satisfy both low cogging torque, low torque ripple and high efficiency.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.4
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• pp.96-103
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• 1998

With the advance of processing technology , so as to spare fuel, piston heads used in automobile reciprocating engine have complex 3-dimension, with respect to shape such as ovality, profile, eccentricity, offset, recess. Therefore, coming out of the existing process work used master cam. the process work is performed using a CNC lathe. For a precision processing, the processing work is need to make study of high speed feed gear synchronized with the rotative speed of main spindle. And then the high speed feeding system must maintain high dynamic stiffness, high speed and high positioning accuracy . In this paper, in order to achieve high speed cutting tool feeding. The linear brushless DC motor is used for satisfying this process work. The ball bush and turicite is used as the guidance of the feed gear system. Also linear encoders, digital servo amplifiers and controller are used for controlling driving motor. This paper presents the design and simulation of the new tool feed system for noncircular machining.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.330-333
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• 2003

In this thesis. the application of the synchronizing control of the intelligent indoor lift system is showed. The separate axes of the indoor lift system are driven independently. PID controller, synchronous flexible logic compensating method and tilt sensor are applied to enhance the performance of the intelligent indoor lift system. the tilt sensor senses the horizontal error of the whole system. PID controller and synchronous flexible logic are used to compensate the synchronous errors of both the separate axes and whole system to be zero. Namely, using not the hardware coupling but the software algorithm. the indoor life system is operated without the error. Before applying the real system, the simulation using matlab testifies the possibility of the lift system. And the realization of the system is demonstrated with two DC servo motors. In the experiment test, flexible logic to compensate the synchronous error is chosen by the comparative method. the indoor lift system has to be considered the loading factor as the disturbance. Because the intelligent indoor lift system is developed to support the patients who don't change for themselves to move. finally, the system which considers the weight of the patient as the disturbance can carry the patients safely without synchronous and position error.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.393-400
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• 1992

The DC(Direct-Current) servo motor has widely used for many application areas, FA(Factory Automation), OA(Office Automation) and home applications. But DC servo motor needs periodical inspection because it has brush and commutator. Recently, AC servo motor has expanded it's application areas due to for the development of the power semi-conductor and control technology. But it has large torque ripple for it's small number of commutation. And it also has cogging torque due to permanent magenet rotor. Therefore it can't run balence rotarion. Many torque ripple reduction methods are published. In this paper, phase advanced method adopted for torque ripple reduction of AC servo motor. In this research, AC servo motor torque characteristic variation surveied under the phase advance control through the computer simulation. Under the simulation, the load inertia varied from 0.0001[Kg.m$^{2}$] to 0.0314[Kg.m$^{2}$]. The result os nonlinear simulation, torque and speed ripple of AC servo motor under the phase advance control reduced approximately 50[%] and 10[%]. And maximum torque of AC servo motor under phase advance control condition increased about 5[%] as compare with fixed switching time.