• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.6
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• pp.164-169
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• 2000

Recently, High accuracy and precision are required in various industrial field especially, semiconductor manufacturing apparatus, Ultra precision positioning apparatus, Information field and so on. Positioning technology is a very important one among them. As such technology has been rapidly developed, this field needs the positioning accuracy as high as submicron. It is expected that the accuracy of 10nm and 1nm is required in precision work and ultra precision work field, respectively by the beginning of 2000s. High speed and low vibration are also needed. This work deals with the design method and control system of Ultra precision positioning apparatus. Control performance and stability analysis were performed in advance by modeling and designing the controller with Simulink.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.10
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• pp.571-578
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• 1999

Current waveform control of pulse MAG welding power source is studied so that welding of thin plates may obtain high speed and improved performance. In this paper, waveform control method is proposed, digital controller using DSP is able to control the current waveform precisely. High speed welding of thin plates using pulse MAG welding method is made possible. Performance test for 1.2mm thin plates is carried out, output waveform and welding performance is analyzed.

• The Transactions of the Korean Institute of Power Electronics
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• v.7 no.1
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• pp.81-90
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• 2002

This paper presents an Implementation of digital high-performance position sensorless control system of Reluctance Synchronous Motor(RSM) drives with Direct Torque Control(DTC). The system consists of stator flux observer, speed and torque estimator, two digital hysteresis controllers, an optimal switching look-up table, Insulated Gate Bipolar Transistor(IGBT) voltage source inverter, and TMS320C31 DSP board. The stator flux observer Is based on the combined voltage and current model with stator flux feedback adaptive control of which inputs are current and voltage sensed on motor terminal for wide speed range. In order to prove the suggested sensorless control algorithm for industrial field application, we have some simulation and actual experiment at low and high speed range. The developed high-performance speed control by fully digital system are shown a good response characteristic of control results and high performance features using 1.0[kW] RSM having 2.57 reluctance ratio of $L_d/L_q$.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.263-266
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• 1999

This study aims to make high performance concrete for normal strength using crushed stone fines to control high strength of the high performance concrete. According to the experimental results, when crushed stone fines are increased every 10%, 15% of compressive strength is decreased, and 5% of drying shrinkage is increased, compared to normal high performance concrete. Also, high performance concrete has been evaluated to have good durability factor more than 100% in the 480cycle of freezing and thawing test, without regard to using AE and crushed stone fines.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.125.3-125
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• 2001

Recently, aircraft is designed to have high maneuverable at high angle of attack. However, it is very hard to obtain the accurate dynamic model for the high performance, because aerodynamic characteristics are nonlinear and include a lot of uncertainties. Therefore, nonlinear controller without considering uncertainties may degrade the control system performance. On this paper, to overcome these defects, the neural networks based adaptive nonlinear controller is proposed making use of the backstepping technique. Neural networks are implemented to guarantee robustness to uncertainties caused by aerodynamic coefficients variation. The main feature of the proposed controller is that the adaptive controller is developed under the assumption ...

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.5
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• pp.767-773
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• 2013

A high-pressure, high-pressure drop control valve, which transforms the power transfer of a system by reducing the inlet pressure of 345bartothe outlet pressure of 112bar, is a fundamental component in an offshore plant process. With the increasingly growing market share of the maritime industry, this valve has been expected to be a high-value-added product. This study not only analyzes the relation between pressure drop and fluid velocity in a trim by using fluid analysis, but also examines the possibility of cavitation in a valve in addition to the plot for the extension of lifespan. Based on the analysis results, the design and production method of the valve are established, and accordingly, performance evaluation is carried out. It is demonstrated that the pressure drop from 345bar to 112bar is more feasible in the presence of the trim, which can induce a continuous and diminutive pressure drop in order to prevent cavitation in a high-pressure drop control valve. Furthermore, despite the fluid velocity near a seatring being found to be over 30m/s, the lifespan of the valve is determined to be adequate considering the operation condition of a prototype valve of 80%.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.35-42
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• 2019

Nut fasteners that require ultra-precise control are required in the overall manufacturing industry including electronic products that are currently developing with the automobile industry. Important performance factors when tightening nuts include loosening due to insufficient fastening force, breakage due to excessive fastening, Tightening torque and angle are required to maintain and improve the assembling quality and ensure the life of the product. Nut fasteners, which are now marketed under the name Nut Runner, require high torque and precision torque control, precision angle control, and high speed operation for increased production, and are required for sophisticated torque control dedicated to high output BLDC motors and nut fasteners. It is demanded to develop a high-precision torque control driver and a high-speed, low-speed, high-response precision speed control system, but it does not satisfy the high precision, high torque and high speed operation characteristics required by customers. Therefore, in this paper, we propose a control technique of BLDC motor variable speed control and nut runner based on vector control and torque control based on coordinate transformation of d axis and q axis that can realize low vibration and low noise even at accurate tightening torque and high speed rotation. The performance results were analyzed to confirm that the proposed control satisfies the nut runner performance. In addition, it is confirmed that the pattern is programmed by One-Stage operation clamping method and it is tightened to the target torque exactly after 10,000 [rpm] high speed operation. The problem of tightening torque detection by torque ripple is also solved by using disturbance observer Respectively.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.52 no.10
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• pp.583-590
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• 2003

This paper deals with speed control of DC servo motor using a high gain obserber. It was designed to estimate rotor speed of DC servo motor and it carries out speed control from the feedback of the estimated speed signal. Also, PI controller was used in speed controller. In order to verify the performance of the high gain observer which is proposed in this paper, it is compared estimate performance of Luenberger Observer and High Gain Observer with the computer simulation. Effectiveness of the proposed high gain observer is proved from the experiment to compare the case with a speed sensor to the case with high gain observer in the speed control of DC servo motor.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.10
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• pp.59-68
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• 2009

The field oriented control of induction motors is widely used in high performance applications. However, detuning caused by parameter disturbance still limits the performance of these drives. In order to accomplish variable speed operation, conventional PI-like controllers are commonly used. These controllers provide limited good performance over a wide range of operation, even under ideal field oriented conditions. This paper is proposed high performance control of induction motor drive using multi adaptive fuzzy controller. This controller has been performed for speed control with fuzzy adaptation mechanism (FAM)-PI, current control with model reference adaptive fuzzy control(MFC) and estimation of speed using ANN. The proposed control algorithm is applied to induction motor drive system using FAM-PI, MFC and ANN controller. The performance of proposed controller is evaluated by analysis for various operating conditions using parameters of induction motor drive. Also, this paper is proposed the analysis results to verify the effectiveness of this controller.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.519-519
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• 2000

Since the dynamics of the slave manipulator with high reduction ratio joints is likely to be much slower than that of the master manipulator, the control input the slave manipulator is so frequently saturated. This paper proposes a bilateral teleoperation control scheme for 2-DOF manipulators with high reduction ratio joints, which can effectively compensate the control input saturation. In the proposed scheme, the controllers of the slave manipulator are designed with an anti-windup feature and forces caused by the saturation are reflected to the operator holding the operating handle of the master manipulator. When the control input of the slave manipulator is saturated, the master manipulator moves slowly file to tile reflected forces. In this way, the position tracking performance of the slave manipulator with high reduction ratio joints can be enhanced regardless of saturation. The proposed scheme is shown to give excellent position tracking performance through a series of experiments.