• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.1046-1051
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• 1991

For the conveyor tracking application of a robot manipulator, a new control scheme is presented. The presented scheme is divided into two stages : the upper one is the motion planning stage and the lower one is the motion control stage. In the upper stage, the nominal trajectory which tracks the part moving in a constant velocity, is planned considering the robot arm dynamics. On the other hand, in the lower level, the perturbed trajectory is generated to track the variation in the velocity of conveyor belt via sensory feedback and the perturbed arm dynamics. In both stages, the conveyor tracking problem is formulated as an optimal tracking problem, and the torque constraints of a robot manipulator are taken into account. Simulation results are then presented and discussed.

• 한국전자통신학회논문지
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• 제7권4호
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• pp.839-848
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• 2012

본 논문에서는 외란토크를 효과적으로 억제할 수 있는 AC 서보모터의 견실제어 방법을 제안한다. 제안된 제어기는 플랜트 모델에 기초한 피드포워드제어기와 안정화 피드백제어기로 구성된다. 피드포워드제어기는 공칭(nominal) 플랜트의 출력이 기준 속도명령을 정확히 추적하도록 설계되며 피드백제어기는 전체 폐루프시스템을 안정화시키는 역할을 한다. 피드백제어기는 임의로 선택될 수 있는 자유함수를 포함하는데 이 자유함수는 외란토크의 영향을 억제하고 제어기가 모델오차에 견실하게(robust) 동작되도록 선택될 수 있다. 컴퓨터 시뮬레이션을 통하여 제안된 제어방식이 기존의 제어방식들에 비해 우수한 제어성능을 가짐을 입증한다.

• Journal of Electrical Engineering and information Science
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• 제2권4호
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• pp.53-58
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• 1997

In this paper, the power system stabilizer(PSS) using the sliding mode observer-model following(SMO-MF) with closed-loop feedback (CLF) for single machine system is extended to multimachine system. This a multimachine SMO-MF PSS for unmeasureable plant state variable is obtained by combining the sliding mode-model following(SM-MF) including closed-loop feedback(CLF) with the full-order observer(FOO). And the estimated control input for unmeasurable plant sate variables is derived by Lyapunov's second method to determine a control input that keeps the system stable. Time domain simulation results for the torque angle and for the angular velocity show that the proposed multimachine SMO-MF PSS including CLF for unmeasurable plant sate variables is able to damp out the low frequency oscillation and to achieve asymptotic tracking error between the reference model state at different initial conditions and at step input.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2211-2216
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• 2005

This paper describes a novel navigation algorithm using a locomotion interface with two 6-DOF parallel robotic manipulators. The suggested novel navigation system can induce user's real walking and generate realistic visual feedback during navigation, using robotic manipulators. For realistic visual feedback, the virtual environment is designed with three components; 3D object modeler for buildings and terrains, scene manager and communication manager component. The walking velocity of the user is directly translated to VR actions for navigation. Finally, the functions of the RPC interface are utilized for each interaction mode. The suggested navigation system can allow a user to explore into various virtual terrains with real walking and realistic visual feedback.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.1027-1030
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• 1996

The purpose of this study was to develop systematic diagnostic system testing easily, rapidly vestibular function of patients suffered from vestibular syndrome such as nausea vomiting, dizzness, ataxia. Diagnostic system composed of rotatory chair system which rotated sinusoidally patients against their vertical axis for purpose of invoking eye movement by vestibulo-ocular reflex and the softwares which storaged eye movement into computer and analyzed eye movement. Rotatory chair system consisted of comfortable chair and DC servomotor with reducer(1:80) by controlled servo in field of nonlinear motor control, double feedback loops system containing velocity feedback loop and position feedback loop was applied to this sever controlled rotatory chair system. Maximum rotatory velocity of rotatory chair was upto 60 degree per second and frequency range was 0.01 to 0.64 Hz. These above results suggest that clinical rotatory chair system may test easily, rapidly vestibular function and diagnose etiology of dizziness, thus giving effective assistance on the treatment of dizziness patients.

• Structural Engineering and Mechanics
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• 제55권1호
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• pp.229-244
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• 2015

H-infinity norm relates to the maximum in the frequency response function and H-infinity control method focuses on the case that the vibration is excited at the fundamental frequency, while 2-norm relates to the output energy of systems with the input of pulses or white noises and 2-norm control method weighs the overall vibration performance of systems. The trade-off between the performance in frequency-domain and that in time-domain may be achieved by integrating two indices in the mixed vibration control method. Based on the linear fractional state space representation in the modal space for a piezoelectric flexible structure with uncertain modal parameters and un-modeled residual high-frequency modes, a mixed dynamic output feedback control design method is proposed to suppress the structural vibration. Using the linear matrix inequality (LMI) technique, the initial populations are generated by the designing of robust control laws with different H-infinity performance indices before the robust 2-norm performance index of the closed-loop system is included in the fitness function of optimization. A flexible beam structure with a piezoelectric sensor and a piezoelectric actuator are used as the subject for numerical studies. Compared with the velocity feedback control method, the numerical simulation results show the effectiveness of the proposed method.

• Smart Structures and Systems
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• 제24권1호
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• pp.67-81
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• 2019

Rows of closely adjacent buildings with similar dynamic characteristics are common building arrangements in residential areas. In this paper, we present a vibration control strategy for the seismic protection of this kind of multibuilding systems. The proposed approach uses an advanced Linear Matrix Inequality (LMI) computational procedure to carry out the integrated design of distributed multiactuation schemes that combine interbuilding linking devices with interstory actuators implemented at different levels of the buildings. The controller designs are formulated as static output-feedback H-infinity control problems that include the interstory drifts, interbuilding approachings and control efforts as controlled-output variables. The advantages of the LMI computational procedure are also exploited to design a fully-decentralized velocity-feedback controller, which can define a passive control system with high-performance characteristics. The main ideas are presented by means of a system of three adjacent five-story identical buildings, and a proper set of numerical simulations are conducted to demonstrate the behavior of the different control configurations. The obtained results indicate that interstory-interbuilding multiactuation schemes can be used to design effective vibration control systems for adjacent buildings with similar dynamic characteristics. Specifically, this kind of control systems is able to mitigate the vibrational response of the individual buildings while maintaining reduced levels of pounding risk.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 추계학술대회논문집
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• pp.262-267
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• 2000

The flexural vibration of aluminum beams with active and passive constrained-layer damping has been investigated experimentally to design structure with maximum possible damping capacity. Piezoelectric film is used as sensor and piezoceramic as actuator for negative velocity feedback control. This paper shows the effectiveness of active constrained-layer damping treatment through experiment, and we have carried out an experiment to study effect of beam thickness.

• 한국정밀공학회지
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• 제12권9호
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• pp.104-114
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• 1995

Mathematical models of industrial robots or manipulators are composed of highly nonlinear equations with nonlinear couplings between the variables of motions. These nonlin- earities were not considered important in the first stage that the working speed of the manipulator was not so fast, but the effect of nonlinear forces has become serious, as the working speed has been increased. So more improvement of performance cannot be expected by the control of manipulator using approximate linearization. As an approach for solving these problems, there is a method that eliminates nonlinear theory, which makes possible cecoupling of coupling terms and arbitrary arranging of poles is briefly introduced in this study. When the theory is applied to design the control law, its feasibility is examined whether the reasonable control results are obtained by simulating position, velocity, torque and tracing trajectory. The relations between the coefficients of the linearized differential equations and the maximum error and torque for the prescribed trajectory are also examined. Finally, the method for selecting the values for getting the most rapid and precise response within maximum torque of each drive is suggested in the choice of coefficients of characteristic equations which are obtained as a result of the control.

• 대한기계학회논문집A
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• 제33권5호
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• pp.482-488
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• 2009

Dancer system is typically used equipment for attenuation of tension disturbances. In industrial converting machines, a composite type of dancer system is applied which is mixture of active and passive dancer. It includes feedback position control loop of roll with pendulum dancer and its characteristics is different from passive and active one. In this paper, a mathematical model of the pendulum dancer was derived including PI position feedback controller and it was analyzed by using a pole-zero map and bode plot under various conditions. It was found out that velocity, length of span and inertia were associated with the performance of regulation. It was suggested that the length of upstream span should be greater than that of the downstream and the inertia should be smaller for improvement of the performance. The results can be used for design guidelines of the industrial dancer system.