• Journal of Navigation and Port Research
• /
• v.31 no.6
• /
• pp.531-536
• /
• 2007

In this paper we present an interpolation-LQ control technique which tunes continuously the controller gain by interpolating the gains of sub-LQ controllers. The proposed controller design technique is applied to the container crane system for simulations. Several cases of simulations are carried out in order to prove the control effectiveness and robustness. The simulation results of the proposed controller are compared with those of LQ controllers. The results showed better control performance than those of LQ controllers.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.34 no.11
• /
• pp.35-41
• /
• 2006

This paper proposes an algorithm for switching LQ(Linear Quadratic) controllers designed at each flight envelope without a bump phenomenon. This algorithm is derived to apply to LQ controller more easily than existing implementation algorithm and is proposed to consider trim points of nonlinear models, which is adequate to real applications. This paper exemplifies the control performance improvement via simulations applied to LQ control of a supersonic test aircraft as a benchmark problem to test the proposed algorithm performance.

• 제어로봇시스템학회:학술대회논문집
• /
• 1993.10a
• /
• pp.987-993
• /
• 1993

A loop-shaping LQ controller is synthesized for tandem cold mills. And a new loop-shaping technique is suggested for LQ controller design. The suggested loop-shaping LQ control system is compared with the standard loop-shaping LQ control system. The simulation results show that the thickness and interstand tension control accuracy of tandem cold mills can be improved by the compensated loop-shaping LQ controller.

• Journal of the Korean Society for Precision Engineering
• /
• v.11 no.5
• /
• pp.66-74
• /
• 1994

A loop-shaping LQ controller is synthesized for tandem cold mills. And a new loop- shaping technique is suggested for LQ controller design. The suggested loop-shaping LQ control system is compared with the standard loop-shaping LQ control system. The simulation results show that the theickness and interstand tension control accuracy of tandem cold mills can be improved by the compensated loop-shaping LQ controller.

• Journal of Institute of Control, Robotics and Systems
• /
• v.3 no.2
• /
• pp.115-123
• /
• 1997

이산기간 H/sub .inf./ 제어에 의한 최적 예견제어기를 제안한다. 기존의 H/sub .inf./ 제어기는 미지의 외란만 고려한 것이고, LQ 에 의한 예견제어기는 예견 가능한 외란과 미지의 외란이 동시에 가해지는 동적 시스템의 전달함수 행렬의 infinity 놈의 최소화하는 피드백제어기가 동시에 설계된다. 제어기의 설계는 full-information H/sub .inf./ 제어 이론을 따르나, 그 유도 과정은 LQ 에 기초한 예견제어기와 유사하게 이루어진다. 설계된 H/sub .inf./ 예견 게인 행렬은 LQ 예견 게인 행렬과 유사한 구조를 갖는다. 전달함수 행렬의 infinity 놈이 .inf.로 갈수록 H/sub .inf./ 예견 게인 행렬은 LQ에 의한 것에 접근한다. LQ 예견 게인 행렬은 H/sub .inf./ 예견 게인 행렬의 부분 집합임이 입증한다.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.10a
• /
• pp.307-308
• /
• 2006

• Journal of Power System Engineering
• /
• v.7 no.4
• /
• pp.74-81
• /
• 2003

An LQ controller design method is proposed for effective anti-sway control of boom type crane in this paper. It is important for high productivity that the sway of a load is controlled as fast as possible when the trolley arrives to the destination with maximum velocity. To prove the effectiveness of the proposed LQ controller. simulations and experiments using the boom type crane as experimental device is carried out. Tracking performance for a step type reference and robustness for the change of working environment such as the change of load weight and parameters produced by a wire rope and disturbance by the wind arc proved by the experiment. It will be examined that boom type crane can be applied to industrial fields through experiment in this paper.

• Journal of Advanced Marine Engineering and Technology
• /
• v.25 no.3
• /
• pp.623-630
• /
• 2001

The conventional control techniques based a mathematical model are not well suited for dealing with ill-defined and uncertain system like a linear quadratic control. Recently, fuzzy control has been successfully applied to a wide variety of practical problems such as robot, water purification, automatic train operation system etc. In this paper, a design technique of robust Fuzzy-LQ controller for each subsystem is designed. Secondly , all the subsystem controllers are combined by fuzzy weighted averaging method. Finally the effectiveness of the proposed controller is verified through a series of computer simulations for an inverted pole system.

• Journal of Institute of Control, Robotics and Systems
• /
• v.1 no.2
• /
• pp.83-87
• /
• 1995

본 논문에서는 이산시간 LQ 조절기의 안정도 강인성을 주파수 영역및 시간영역에서 고찰하고 그 향상책을 제시하낟. 주파수영역에서 강인성 척도인 궤환차행렬(return difference matrix) 의 최소특이치가 상태가중치 행렬과 제어가중치 행렬의 비와 반비례함을 보이고, 시간영역에서 매개변수의 변화에 대한 안정도 강인성 범위들을 얻는다. 이 범위들의 점근적 성질을 밝히기 위하여 LQ 궤환이득의 특이치들이 상태가중치 행렬과 제어기중치 행렬의 비의 증가함수 임을 보인다. 몇가지 조건하에서 시스템 행렬(입력행렬)에 대한 안정도 강인성 범위가 상태 가중치 행렬과 제어가중치 행렬의 비가 증가(감소)함에 따라서 증가함을 보이고, 이러한 사실들을 예제를 통하여 검증한다.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.41 no.3
• /
• pp.1-8
• /
• 2004

This paper proposes an LQ-PID controller to reduce errors occurring between input and output speeds in braking or emergency braking and to solve delay of speed or the excessive overshoot problems occurring at the speed control of induction motor. The conventional LQ controller is a method that move the poles in locations that satisfy design specifications such as overshoot and settling time etc. by state-feedback. So it may not be able to satisfy the overshoot requirement in case of the existence of zero in the closed loop transfer function. To attack this zero-problem it is presented a new design methodology of LQ-PID controller by introducing an analytic technique to eliminate the effect of zeros on the closed loop transfer function.