• Journal of Mechanical Science and Technology
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• 제18권2호
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• pp.203-210
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• 2004

Attitude control law design for spacecraft large angle maneuvers is investigated in this paper. The feedback linearization technique is applied to the design of a nonlinear tracking control law. The output function to be tracked is the quaternion attitude parameter. The designed control law turns out to be a combination of attitude and attitude rate tracking commands. The attitude-only output function, therefore, leads to a stable closed-loop system following the given reference trajectory. The principal advantage of the proposed method is that it is relatively easy to produce reference trajectories and associated controller.

• 한국항공우주학회지
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• 제43권8호
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• pp.731-738
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• 2015

항공기 비행제어시스템의 개발기간, 비용 및 위험도를 최소화시키기 위해서는 비행제어 법칙의 적용 및 시험을 효율적으로 수행할 수 있는 통합개발 도구와 Rapid Prototyping 프로세스가 요구된다. 본 논문에서는 Matlab/Simulink 환경을 통해 생성한 제어법칙 자동코드와 비행동역학 해석프로그램(HETLAS: HElicopter Trim, Linearization and Simulation)과의 연동 절차를 개발하여 시뮬레이션 평가를 효율적으로 수행할 수 있는 환경의 구축에 대해 기술하였다. 또한, 본 연구를 통해 제어법칙의 다양한 모드의 조종사 시뮬레이션 평가를 위해 HETLAS를 이용한 데스크탑 시뮬레이션 환경을 개발하고 조종성 시뮬레이터 및 HILS(Hardware In the Loop Simulation) 시험 환경과 효율적으로 연동하여 시험할 수 있는 절차를 개발하였다. 비행제어법칙 개발과정에서 HETLAS를 중심으로 한 해석/시험 환경을 개발함으로써 반복적인 제어법칙의 설계/해석 및 시험 절차를 효율적으로 수행할 수 있도록 하였다.

• International Journal of Aeronautical and Space Sciences
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• 제15권2호
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• pp.163-172
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• 2014

This paper proposes a novel guidance law based on the block backstepping sliding mode control and extended state observer (ESO), which also takes into account the autopilot dynamic characteristics of the near space interceptor (NSI), and the impact angle constraint of attacking the maneuvering target. Based on the backstepping control approach, the target maneuvers and the parameter uncertainties of the autopilot are regarded as disturbances of the outer loop and inner loop, respectively. Then, the ESO is constructed to estimate the target acceleration and the inner loop disturbance, and the block backstepping sliding model guidance law is employed, based on the estimated disturbance value. Furthermore, in order to avoid the "explosion of complexity" problem, first-order low-pass filters are also introduced, to obtain differentiations of the virtual control variables. The stability of the closed-loop guidance system is also proven, based on the Lyapunov theory. Finally, simulation results demonstrate that the proposed guidance law can not only overcome the influence of the autopilot dynamic delay and target maneuvers, but also obtain a small miss distance.

• 한국항공우주학회지
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• 제46권10호
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• pp.814-822
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• 2018

본 논문은 제어시간이 제한된 유도탄에 적용하기 위한 유도법칙을 제안한다. 제안된 유도법칙은 잔여비행시간에 대한 다항식을 기반으로 설계되어 일반화된 형태를 가지게 된다. 또한 제어 종료시점에서 가속도 명령을 0으로 만들어 잔여비행시간(time-to-go) 추정 오차에 대한 민감도를 줄여주고, 단 분리 등의 이벤트 발생 시 비행 안정성을 증가 시켜줄 수 있다. 제안된 유도법칙을 적용하기 위한 잔여비행시간 추정방법을 제안하고, 고고도 방어요격탄의 중기 유도 및 종말 유도에 대한 적용 가능성을 제시한다. 다양한 시뮬레이션 수행을 통하여 제안된 유도법칙의 특성 및 성능을 분석한다.

• Strategy21
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• 통권38호
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• pp.13-46
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• 2015

Dokdo issue reaches beyond economic and security interest to Koreans, as it is regarded as symbol of her independence. Albeit the fact that Japan has merely no legitimate title over Dokdo, Japan has been tenaciously insisting their jurisdiction over Dokdo since the independence of Korea. Under such circumstances, public outrage towards Japan is most certainly understandable. Yet, mere outrage itself, lacking in logic and factual grounds, can contribute little if not any, to the desirable solution of the problem. Precedents reveal that dealing maritime issues amid lack of profound understanding in international law has often led to undesirable results, such as the inclusion of Dokdo in the Joint Management Fisheries Zone in 1999 Korea-Japan Fisheries Agreement. In a sense, adroit use of international law is a critical element in preserving Korea's sovereign rights against persistent Japanese plans to rob Dokdo once again. The Dokdo issue is inextricably bound to international law; the legal status of Dokdo as island, the equitable solution of maritime boundary delimitation and effective control, existence of dispute. Yet, the public policies and arguments made by pundits are generally in lack of understanding in international law. It is now the time for Korea to commence on long-term cross-academia / department plans to establish Dokdo strategy as part of the nationwide maritime strategy effectively using international law as its stronghold.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집(한일합동학술편); 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.801-806
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• 1987

The receding horizon tracking control for the discrete time invariant systems is presented in this paper. This control law is derived with the receding horizon concept from the standard tracking problems. Stability properties of this control law are analyzed. It is shown that there exists a finite horizon index for which the closed loop systems are always asymptotically stable. The receding horizon tracking control is a kind of predictive control and will add a new clan to many existing predictive controls, with which some comparisons are made.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.38.1-38
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• 2001

In this paper, the vibration suppression problem of an axially moving power transmission belt is investigated. The equations of motion of the moving belt is first derived by using Hamilton´s principle for systems with changing mass. The total mechanical energy of the belt system is considered as a Lyapunov function candidate. Using the Lyapunov second method, a nonlinear boundary control law that guarantees the uniform asymptotic stability is derived. The control performance with the proposed control law is simulated. It is shown that a boundary control can still achieve the uniform stabilization for belt systems.

• 제어로봇시스템학회논문지
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• 제20권4호
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• pp.395-401
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• 2014

Magnetic levitation systems using the attraction force of electromagnets have many constraints according to the variation of air gap and the nonlinearity of electromagnetic force and inductances. As a result of these constraints, the nonlinear control of a magnetic levitation system has been improved by the latest advanced processors and accurate measurement system which can overcome problems such as many constraints and nonlinearity. This paper concentrates on the modeling of a nonlinear magnetic levitation system and an application of an exponential reaching law based sliding mode controller using the exponential reaching law which is one of the most robust controllers against external unexpected disturbances or parameter fluctuations. Controllability of a magnetic levitation system using the sliding mode control algorithm and robustness against parameter fluctuations have been verified through the experimental results.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.1647-1650
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• 1997

This paper presents the control law of Automatic Rudder Trim System(ARTS) for the KTX-1. The proposed ARTS is designed mainly t reduce the pilot's work load for trimming in the various conditiions of engine torque. airspeed, and aircraft configuration. The ARTS partially compensates the transient yawing motion due to change of engine power in turboprop aircraft because of the limitation of the actuation speed of the trim motor. In this paper flight test data are analyzed to understand the phenomena and the dynamics of the reversible rudder flight control system is derived. Finally, the control concept and conrtol law of ARTS are described and the characteristics of the ARTS are analyzed through simulation study.

• 대한기계학회논문집A
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• 제21권11호
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• pp.1809-1818
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• 1997

Mathematical models of industrial robots or manipulators are highly nonlinear equations with nonlinear coupling between the variables of motion. As the working speed has been fast, the effects of nonlinear terms have become serious. So the control algorithm based on approximately linearized equation looses the efficiency. In order to design the control law for the nonlinear models, Hunt-Su's nonlinear transformation method and Marino's feedback equivalence condition are used with linear quadratic regulator(LQR) theory in this study. Nonlinear terms of the system are eliminated and coupled terms are decoupled by this feedback law. This method is applied to a 3-D.O.F. vertical articulated manipulator by both experiments and simulations and compared with PID control which is widely used in the industry.