• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.79-83
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• 2001

A cone-shaped active magnetic bearing spindle system for high speed internal grinding is designed and tested. The cone-shaped AMB system consists of only 4 couples of magnet, it can be smaller and lighter than conventional radial-axial-type AMB system. In this paper, the cone-shaped electromagnets are designed by magnetic circuit theory, and de-coupled direct feedback PID controller is applied to control the coupled magnetic bearings. The designed cone-shaped AMB spindle system is built and constructed with a digital control system, and tested its stbility and dynamic performances. As the results of the tests, this spindle runs up to 40,000 rpm with about 5 ${\mu}{\textrm}{m}$ of runout, and the AMB system provides high damping ratio eliminating overshoot and resonance speed.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.5
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• pp.714-719
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• 2012

In this paper, the polishing force monitoring and the control method were implemented for the polishing machine with the airbag tool. Airbag tool has been known to be adaptable to the curvature variation such as the aspherical and the free-form surface. However, it was necessary to control the tool movement of vertical axis also because of the table rotational wobble and vibration. To solve it by the polishing force control, we installed another stepping motor to the z-axis. And the polishing force was measured with the load cell and controlled by the PID Labview controller. A few hundreds gram of the polishing force were well controlled under 0.8 second of the response time and 5% variation. An experiment was done to clean the edge burrs of the micro channel structure of width $87{\mu}m$ using the polishing force control.

• Annual Conference of KIPS
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• 2016.10a
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• pp.404-405
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• 2016

본 논문은 자율주행로봇의 평면 공간 주행과 평면 공간상의 Map 정보를 생성하는 것에 관한 것이다. 자율주행 로봇은 Raspberry Pi, Sonar Sensor, Gyro Sensor를 사용해 궤적 이동에 대한 정보를 수집한다. 자율주행로봇은 정확한 직진 주행 및 회전 이동을 위해 개선된 모터 제어 기법인 PID Controller를 사용한다. 정확한 Map 정보를 생성하기 위해서 System은 주행 중에 수집한 궤도의 정보를 2차원 배열과 LIFO 자료 구조에 기록하여 Map Information을 생성해 나간다.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.980-981
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• 2006

전력변환 장치에서 기존의 PID 제어기의 해석적인 해를 얻는 것은 매우 어려운 일이다. 최근에 단상 UPS용 인버터 시스템에서 CRA 기법을 이용한 새로운 제어알고리즘을 바탕으로 시스템의 제어기의 제어상수를 해석적으로 접근하여 좋은 성능을 얻은 바 있다. CRA 기법은 해석적으로 시스템의 응답속도 및 오버슈트를 임의의 제한범위 내로 설계할 수 있도록 하는 장점이 있다. 이러한 CRA 기법을 사용하여 컨버터 제어기 설계부분에 적응하여 해석적인 해를 얻고 PSiM 시뮬레이션을 통해 오버슈트와 빠른 응답을 확인한다.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.336-339
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• 2005

This paper presents a PM type BLDC(Brushless DC) Motor servo drive system using high performance DSP TMS320F2812. The DSP controller with 150MIPS enables an enhanced real time implementation and increased efficiency and high performance for motor drive. The suggested drive system consists of PI action for the constant speed control and PID action for the current control with only 3 Halls, no encoders. The developed servo drive control system shows a good response speed characteristics at high speed up to 10000 [rpm].

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.754-756
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• 2000

In this paper, the I-PD control algorithm using the coefficient diagram method(CDM) controller design of the Linear DC Motor(LDM) is presented. Recently LDM has been used to obtain the fine results of the dynamic characteristic for straightly moving condition. The I-PD control algorithm has a robust response to force disturbance. The effectiveness of I-PD is shown by simulations and comparison with PID.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.861-863
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• 2003

In this paper, a controller for a non-contact bearing-based motor-generator system is designed. The levitation control method is a digital PID control. The plant dynamics consisting of actuator and rigid rotor dynamics are described. And some experiments are conducted with each global control and local control concept. From the whirl test, the Motor-Generator System can be controlled within about ${\pm}10{\mu}m$ gap variation at the rotational speed of 600rpm and generate electric power of AC100V.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.111-112
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• 2006

A new MR cylinder with built-in valves using Magneto - Rheological fluid (MR valve) is proposed for fluid power control systems. The MR fluid is a newly developed functional fluid whose obvious viscosity is controlled by the applied magnetic field intensity. This MR cylinder, which is composed of cylinder with small clearance and piston with electromagnet, has the characteristics of simple, compact and reliable structure. This paper presents a method to control the pressure of MR cylinder by using Generalized Predictive Control (GPC) algorithm. The differential pressure is controlled by applying magnetic field intensity to MR fluid. The use of GPC controller is to generate a control sequence by minimizing a cost function in such a way that the future system output is driven close to reference over finite prediction horizons. Experimental results from real time control using GPC method compared with conventional PID control method are also shown in this paper.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.10 s.253
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• pp.1261-1268
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• 2006

This paper reports low-cost microreactor $(10{\mu}{\ell})$ biochip for the DNA PCR (polymerase chain reaction). The microbiochip $(20mm{\times}28mm)$ is a hybrid type which is composed of PDMS (polydimethylsiloxane) layer with serpentine micochannel $(360{\mu}m{\times}100{\mu}m)$ chamber and glass substrate integrated with microheater and thermal microsensor. Undesirable bubble is usually created during sample loading to PMDS-based microchip because of hydrophobic chip surface. Created bubbles interrupt stable biochemical reaction. We designed improved microreactor chamber using microfluidic simulation. The designed reactor has a coner-rounded serpentine channel architecture, which enables stable injection into hydrophobic surface using micropipette only. Reactor temperature needed to PCR reaction is controlled within ${\pm}0.5^{\circ}C$ by PID controller of LabVIEW software. It is experimentally confirmed that SRY gene PCR by the fabricated microreactor chip is performed for less than 54 min.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.4 s.175
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• pp.839-847
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• 2000

This paper presents modal analysis and mean conveying velocity (M.C.V.) control of bowl parts feeder activated by piezoactuators. Bowl parts feeders are being widely used in many industry fields for automatic assembly line. In general, the electromagnet has been and being used as exciting actuator of these vibratory bowl feeders. However, because of complexity of its mechanism and limited capability of the electromagnet actuator, there exist various impending problems such as severe noise, nonlinear motion of parts, passive characteristics and so forth. As one of solutions for these problems, piezoelectric actuators as new actuating technology have been proposed recently to excite the bowl parts feeder. In this paper, modal analysis of the proposed model has been performed to examine the modal characteristics of the model by using commercial FEM software and modeling with respects to MCV is constructed. Finally, MCV of the parts is to be controlled to track the desired one with PID controller.