• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1309-1314
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• 2003

The high precision positioning mechanism is used in various industrial fields. It is used in semiconductor manufacturing line, test instrument, Bioengineering, and MEMS and so on. This paper presents a positioning mechanism with dual servo system. Dual servo system consists of a coarse stage and a fine motion stage. The course stage is driven by VCM and the actuator of fine stage is the PZT. The purposes of dual servo system are stability, higher bandwidth, and robustness. Lead compensator is applied to this control system, and is designed by PQ method. Designed compensator can improve property of positioning mechanism.

• 한국정밀공학회지
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• 제9권3호
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• pp.29-41
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• 1992

According to the recent increase of demands for multi-function and economics on hydraulic excavator, it is required that excavator should have simple operation, higher and operational efficiency, however the modeling of engine/pump system of excavator is not prescribed by the paper. So, in this paper the modeling of engine/pump system of excavator is suggested by identification method from step response and verified effectiveness of identification system by comparing with experimental results which was conducted using PID controller. To improve the problem of parameter variation and modeling error in the system, sliding mode control was introduced and new switching surface was designed. This control algorithm was applied to a hydraulic excavator by simulation, and its effectiveness was verified, and the results of variable structure system for the excavator system using a output component was compared with that of full state feedback when load disturbances and system paramenter variation exist.

• 대한기계학회논문집A
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• 제27권6호
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• pp.871-878
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• 2003

With the development of micro -technology, the demand for micro actual ing device is increasing. But, it is difficult to achieve high resolution and wide bandwidth with the conventional contact systems. So, the contact-free systems which are suspended or levitated by magnetic force or air bearing were proposed. These systems can be applied to high precision stages and alignment apparatuses. This paper describes a magnetically suspended system with four degrees of freedom which are composed of three rotations (roll, pitch, yaw), and one translation ( z). The operating principle and the structure of the system are similar to variable reluctance type electric machines. In this study, the force analysis is executed using magnetic circuit and virtual work principle, and the equations that describe the dynamics of the system are presented. The multivariable PID controller is adapted to the system and the experiment is executed.

• 전자공학회논문지B
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• 제31B권10호
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• pp.44-52
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• 1994

In this paper, we assume that the dynamics of DC motor and nonlinear load are unknown. We propose an inverse dynamic model of DC motor and nonlinear load using the artificial neural network and construck speed control system based on the proposed dynamic model. We also propose another dynamic model with speed prediction scheme using the artificial neural network that removes the undesirable time delay effect caused by the computation time during the real-time control. We suggest a dynamic model which has arbitrary number of speed arguments and is especially effective when the motor and load has large moment of inertia. Next, we suggest a controller that combine the neurocontrol and PID control with constant gain. We show that the proposed neurocontrol systems have capabilities of noise rejection and generalization to have good velocity tracking through computer simulations and experiments.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 B
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• pp.441-445
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• 1997

In this paper, we suggest a design scheme of receding horizon predictive control(RHPC) for boiler-turbine systems whose dynamics are given in nonlinear equations. RHPC is designed for linear state space models which are obtained at a nominal operating point of the boiler-turbine system. In this consideration, the boiler is operated in a sliding pressure mode, in which the reference value of drum pressure is changing according to the electrical power generation. The reference values of the system outputs are prefiltered before they are fed to the RHPC in order to compensate the linearization errors. Simulation results show that the proposed controller provides acceptable performances in both of the cases of 'steep and small changes' and 'slow and large changes' of power demand and yields the effect of modest coordination of conventional PID schemes such as boiler-following and turbine-following control.

• 천문학회보
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• 제38권1호
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• pp.69.1-69.1
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• 2013

We are developing Adaptive Optics (AO) system for 1m telescope at Gwacheon National Science Museum Observatory. The beam spot of the Gwacheon 1m telescope. The tip-tilt correction system consists of a CMOS sensor, a tip-tilt mirror and a feed back loop. The beam spot location at the CMOS sensor indicates the tip-tilt components of the incoming light. The tip-tilt mirror is controlled by DAC output voltage calculated by proportional-integral-derivative (PID) controller. This system successfully corrects the tip-tilt motion of the spot.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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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].

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 A
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• pp.382-384
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• 1999

We propose a new method for detecting Backemf of a motor and estimating parameters of a motor using Recursive Least Square Estimator. The motor speed is obtained from the estimated parameters. We experiment the PID speed controller with the estimated speed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 B
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• pp.852-854
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• 1995

This paper proposes a new identification method that utilizes fuzzy inference in parameter identification. The prosed system has an additional control loop where a real plant has replaced by a plant model. Fuzzy rules describe the relationship between comparison results of the features and magnitude of modification in the model parameter values. In this paper, the tuning method which determines parameters of PID controller automatically is described through applying this algorithm to DC servo motor. And we intend to investigate effectiveness of the method by experiments. This method is effective in auto-tuning because the response of the closed loop has verified. The simulated and the experimental results of the dc servo motor are shown to confirm the viability of this method.

• 제어로봇시스템학회논문지
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• 제16권5호
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• pp.446-455
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• 2010

The research presented covers the design and control method of unmanned ground vehicle (UGV). An electric vehicle is used and is driven by DC motor. The power system on the UGV has been adjusted and actuators have been installed for steering and brake automation. A toggle switch is implemented to easily switch between manual and autonomous states. The UGV state is monitored by a velocity sensor, as well as steering and brake position sensors. An emergency stop device was designed and installed to quickly and safely stop the UGV. Different control methods, including the PID controller, were studied for improved steering responsiveness, and results were confirmed through experimentation. Satisfactory performance was achieved and several possible areas of future research have arisen.