• Journal of Navigation and Port Research
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• v.33 no.5
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• pp.323-330
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• 2009

We have been developing an underwater robot for harbour construction using a parallel mechanism The robot is attached to the rope of a crane, which curries a large stone into the undersea The robot's yaw and pitch are controlled by hydraulic cylinders but its roll is uncontrollable. We mount propellers in both side of the robot to generate the roll motion This paper studies on the control for the roll motion of a underwater robot. A gyro-sensor is used to measure the angle in a roll motion We develop the dynamic model to describe the robot's roll motion by a second order non-linear system and identify the model parameters by recursive least square and adaptive identifier. PD control, recursive model based control and adaptive model based control are applied with the dynamic model which computes the control input to compensate disturbances. This paper introduces the underwater robot system and presents the simulated and experimental results of the proposed controller.

• Aerospace Engineering and Technology
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• v.10 no.1
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• pp.98-106
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• 2011

This paper is summarized for designing launch vehicle autopilot structure with attitude angle command from guidance algorithm and for evaluating performance of autopilot using launch vehicle six-degree of freedom simulation program. The suggested autopilot has heritage from KSR-III/KSLV-I upper stage autopilot designing experience, and it has two design point. The one is, it must have same performance with KSR-III/KSLV-I upper stage autopilot, the other is, it must be simple autopilot structure and use low number of variable to apply on-board system. It is evaluated the performance using launch vehicle six-degree of freedom simulation program in case of roll maneuvering and no roll control flight condition.

• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.4
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• pp.321-327
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• 2003

As the continuous casting process is to product slab with high temperature liquid steel, the main role of strand driven roll is to withdraw slab from mold as operator set up casting speed pattern. The strand driven roll in old cast machine is controlled casting speed only. Due to inaccuracies in drive setting up, varying roll diameters, bulging in the product, withdrawal force was distributed irregularly. As a result, because of horizontal crack in slab comer, high casting speed can't be achieved. In this paper, the correlation between the distribution of withdrawal force and slab quality is investigated and the new control algorithm which can be distributed regularly the withdrawal force of strand driven roll is proposed. The principle of proposed algorithm is not to control motor torque directly but to control motor speed reference according to sharing ratio of withdrawal force which is set up in high level controller. The proposed algorithm implemented in POSCO Kwangyang 1-4 continuous casting plant.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1288-1289
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• 2015

본 논문은 고속 주행하는 소형의 수중 운동체의 롤 제어기에 대한 연구를 정리한 결과이다. 모형 PMM 시험의 롤 관련 유체력 계수 값의 오차가 커서 실해역 시험에서 시뮬레이션 결과와는 다른 진동현상이 발생하였으나, 시험 결과를 이용한 튜닝과정을 통하여 안정적인 롤 제어 성능을 획득할 수 있었다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.11
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• pp.1421-1426
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• 2012

Cornering maneuvers with reduced body roll and without comfort loss are important requirements for car manufacturers. An electric active roll control(ARC) system controls the body roll angle by using motor-driven actuators installed at the centers of the front and rear stabilizer bars. Co-simulation using the Matlab/Simulink controller model and the CarSim vehicle model was proposed to evaluate the performance of the ARC control algorithm. To validate the performance of the ARC actuator and system, bench tests and vehicle tests were proposed.

• Journal of the Institute of Convergence Signal Processing
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• v.4 no.2
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• pp.53-60
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• 2003

For the high center of gravity vehicles the roll stiffness of their suspensions is arranged to be very high because such vehicles are in some danger of tipping over in cornering. In some cases, the effective roll stiffness is determined significantly by the compliance of the tires because of the very stiff anti-roll members incorporated in the suspension. In such cases, it is clear that the shock absorbers which may be effective in damping heave oscillations have little effect on roll oscillations. Therefore, wind gusts and roadway unevenness may cause large swaying oscillations. In this paper, to improve the stability for the high center of gravity vehicles a control scheme to augment the damping of the roll mode is proposed. As the feedback signals needed to provide damping of the roll motion, the front or rear steer angles or both are chosen because they are very related to roll motion. The scheme is effective from moderate to high speeds and stabilizes the roll mode without introducing disturbance moments from roadway unevenness as shock absorbers do. The validity on the proposed method is verified through the computer simulation.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.3
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• pp.92-99
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• 2001

This paper presents a simulation study using a robust controller to improve the roll stability of a vehicle. The controller is designed in the framework of an output feedback H$_{\infty}$ control scheme based on the 3DOF linear vehicle model, solving the mixed-sensitivity problem to guarantee the robust stability and disturbance rejection with respect to parameter variations due to laden and running vehicle conditions. In order to investigate the feasibility of the active roll control system in a real car, its performance is evaluated by simulation in a 10DOF full vehicle model with actuator dynamics and tire characteristics.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.3
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• pp.74-80
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• 2004

If the withdrawal force of strand driven roll which is controlled with predetermined speed isn't distributed regularly in continuous casting process, mold level is changed cyclically and slab quality is not good. In this paper, both casting speed control and load sharing control algorithm of strand driven roll according to ratio which is set up by operator at same time is proposed. The proposed algorithm is to share the withdrawal force by following torque current of each driven roll as average torque current by changing speed reference of each driven roll motor. The load sharing control with anti-wind up for improvement transient state is adopted and the proposed algorithm is implemented in POSCO pilot caster.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.5
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• pp.22-28
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• 2011

This paper presents an active roll motion control of a passenger vehicle. The roll controller is designed in the framework of $H_{\infty}$ control scheme based on the 3 DOF vehicle model taking into consideration parameter variations, which affect the roll dynamics, and unmodeled high frequency dynamics for robustness and performance. In order to investigate the feasibility of the active roll control system in a car, its performance is evaluated by simulation in a full vehicle model with nonlinear tire characteristics under various operating conditions. Finally, in order to enhance the performance in a transient region taking into account the limited bandwidth of the actuating module, a hybrid control strategy is presented.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.8
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• pp.122-130
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• 2005

For silent operation, Roll-Screen has been designed by using piezolelectric ultrasonic motor. To drive the ultrasonic motor, a digitally controlled drive system has been designed by using PLD. And to measure the position and velocity of Roll-Screen, encoder with 36 pulse/revolution is used. This paper proposed a new method for a precise velocity control of ultrasonic motor, in spite of using low-level encoder. The proposed method use a non-fixed sampling time and compensate the initial nonlinear characteristics of ultrasonic motors.