• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 1994.10a
• /
• pp.165-169
• /
• 1994

This paper describes the vibration control of a cantilever beam that is reformulated as the sensitivity minimization problem and solved in H$_{\infty}$ controller that is studied widely nowadays. The result of suggested controller is compared with that special form of H$_{2}$ controller, i.e., LQG. Piezoelectric actuator is chosen and disturbance is applied in the form of base excitation to match real aeronautical problems. Simulations are given, whose results reveals the performance of suggested controller is better than LQG in many cases.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.49 no.5
• /
• pp.233-241
• /
• 2000

This paper presents a systematic design procedure of $H_{\infty}$ controller of TCSC for damping low frequency inter-area oscillations in large power systems. Sensitivities of the inter-area mode for changes in line susceptance are computed using the eigen-sensitivity theory of augmented system matrix and TCSC locations are selected using the line sensitivities. The reduced model required for designing a manageable-size $H_{\infty}$ controller is obtained using the reduced frequency domain system identification method and the various weighting functions are tuned systematically to provide a robust performance. The proposed $H_{\infty}$ controller proved to be very effective for damping the inter-area mode of the large KEPCO power system.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.57 no.9
• /
• pp.1624-1627
• /
• 2008

This paper deals with a linear matrix inequality (LMI) approach to the design of a PID controller for an attraction type magnetic levitation system. First, we convert the $H_ {\infty}$ PID controller problem into a static output feedback problem. We then solve the static output problem by using the recently developed penalty function method. Numerical experiments show the effectiveness of the proposed algorithm.

• 제어로봇시스템학회:학술대회논문집
• /
• 1998.10a
• /
• pp.362-366
• /
• 1998

This paper proposes a fast H$\sub$$\infty$/ gain scheduled controller that stabilizes the uncertain nonlinear system with exogenous signals. The controller is constructed at a distinct and fixed value of exogenous signals using H$\sub$$\infty$/ syn-thesis methodology. Then the constructed controller set is switched for the wide range of variation of exogenous signals. Using the derivative gain, the number of constructed and engaged controllers for the fast varying exogenous signal is reduced.

• Proceedings of the KIEE Conference
• /
• 1993.07b
• /
• pp.837-839
• /
• 1993

This study describes an analog controller for SRM drives. The overall scheme of the drive is detailed using an 8/6 SRM configuration. Special efforts are exercised in showing the necessity of the triggering angle advances to enhance the drive characteristics such as output-power increase and good speed-responses.

• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1981-1986
• /
• 2004

In this study, the basic motor control system had been investigated. The controller for this study consists of two main parts, a feedforward controller part and a feedback controller part. Each part will deals with different control problems. The feedback controller deals with robustness and stability, while the feedforward controller deals with response speed. The feedforward controller, used to solve the tracking control problem, is adaptable. To make such a tracking perfect, an adaptive law based on Feedback Error Learning (FEL) is designed so that the feedforward controller becomes an inverse system of the controlled plant. The novelty of FEL method lies in its use of feedback error as a teaching signal for learning the inverse model. The theory in $H^{\infty}$-Control is selected to be applied in the feedback part to guarantee the stability and solve the robust stabilization problems. The simulation of each individual part and the integrated one are taken to clarify the study.

• Journal of Institute of Control, Robotics and Systems
• /
• v.4 no.6
• /
• pp.729-737
• /
• 1998

In this paper, using $\mu$ synthesis algorithm with structured uncertainty, we design controller and apply it for the Two-Inertia resonance(TMS: Two Mass Spring) system. The TMS system is one of the simplest models which generate a torsional vibration. In this system, it is required to design a controller achieving the control performance while suppressing the torsional vibration. Furthermore, when vibration frequency for the system is varying by reason of parameter variations, we should consider parameter variations in controller design. Then, we design two other controller schemes of the PI controller and the standard $H_{\infty}$ controller and compare these controllers with the controller designed by the $\mu$ synthesis robust control method by using simulations and experiments.

• Journal of Power System Engineering
• /
• v.7 no.1
• /
• pp.60-67
• /
• 2003

This paper introduces basic study how to restrain the vibration of a four story shear structure. We have modeled a four story shear structure mathematically and have identified each parameters by experiment. We have gotten a reduced nominal model through modal analyzing method and the $H_{\infty}$ control theory is used in the control system design to get the robust controller. It's shown that the desirable performances is confirmed through the mathematical simulation. And a designed controller applying the $H_{\infty}$ control theory shows the good performance for the impulse disturbance through the simulation results. That is, the robustness of this control system is confirmed for the ability of disturbance rejection and modeling error.

• Proceedings of the KIEE Conference
• /
• 1999.11c
• /
• pp.612-614
• /
• 1999

In this paper a novel sliding mode control is proposed by using $H_2/H_{\infty}$ controller. this technique is constructed based on the augmented system with a virtual state and make it has the dynamics of the original system and then $H_2/H_{\infty}$ controller has robust characteristics of sliding mode control for existing parameter uncertainty. The reaching phase is excluded by setting initial virtual state value appropriately.

• 제어로봇시스템학회:학술대회논문집
• /
• 1996.10a
• /
• pp.44-47
• /
• 1996

An optimal preview controller based on the discrete-time $H_{.inf}$ control is presented. The preview controller is synthesized by considering the bounded unknwon disturbances as well as previewable commands and disturbances. The controller derivation procedure is analogous to the LQ-based scheme. The designed preview gain matrix has a similar structure as the LQ-based one. As the infinity norm .gamma. of the transfer function matrix tends to .inf., the preview gains obtained by $H_{\infty}$ control method approach to the gains by the LQR. The LQ-based preview gains are verified to be subsets of the $H_{.inf}$ -based preview gains..