• Journal of Mechanical Science and Technology
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• 제19권2호
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• pp.618-624
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• 2005

We present a new state-space approach to construct a dynamic output feedback controller which stabilizes a class of linear time invariant systems. All the states of the given system are not measurable and only the output is used to design the stabilizing control law. In the design scheme, however, we first assume that the given system can be stabilized by a feedback law composed of the output and its derivatives of a certain order. Beginning with this assumption, we systematically construct a dynamic system which removes the need of the derivatives. The main advantage of the proposed controller is regarding the controller order, which may be smaller than that of conventional output feedback controller. Using a simple numerical example, it is shown that the order of the proposed controller is indeed smaller than that of reduced-order observer based output feedback controller.

• International Journal of Ocean System Engineering
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• 제1권3호
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• pp.120-135
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• 2011

This paper proposes a model based trajectory tracking control scheme for under-actuated underwater robotic vehicles. The difficulty in stabilizing a non-linear system using smooth static state feedback law means that the design of a feedback controller for an under-actuated system is somewhat challenging. A necessary condition for the asymptotic stability of an under-actuated vehicle about a single equilibrium is that its gravitational field has nonzero elements corresponding to non-actuated dynamics. To overcome this condition, we propose a continuous time-varying control law based on the direct estimation of vehicle dynamic variables such as inertia, damping and Coriolis & centripetal terms. This can work satisfactorily under commonly encountered uncertainties such as an ocean current and parameter variations. The proposed control law cancels the non-linearities in the vehicle dynamics by introducing non-linear elements in the input side. Knowledge of the bounds on uncertain terms is not required and it is conceptually simple and easy to implement. The controller parameter values are designed using the Taguchi robust design approach and the control law is verified analytically to be robust under uncertainties, including external disturbances and current. A comparison of the controller performance with that of a linear proportional-integral-derivative (PID) controller and sliding mode controller are also provided.

• 한국산학기술학회논문지
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• 제13권6호
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• pp.2812-2825
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• 2012

본 연구의 목적은 법학전문도서관의 기존사례 분석을 통하여 공간구성 특성을 조사, 규정하고 교육이념에 부응하는 법학전문도서관 특성을 반영한 계획안의 제시함으로서 법학전문도서관의 계획요소 및 디자인을 제안하고자 하였다. 법학도서관의 공간구성특성을 요약하면 (1) 접근성을 고려한 진입층의 공간구성 (2) 열람공간 이용자 중심의 열람실 공간구성 (3) 교육 및 연구 공간과 열람실의 연계성을 고려한 공간 구성으로 법학도서관의 특성을 규정할 수 있다. 이러한 결과를 토대로 한 법학도서관 설계 시 다음과 같은 디자인 쟁점사항을 도출하였다. 진입층 공간구성은 교육의 장소로서의 이용행태, 접근성과 연계성의 측면을 고려하여 공용공간과 함께 열람공간을 계획하여야 한다. 이용자 중심의 열람실과 서고의 공간구성이 계획되기 위한 방법으로는 일반열람실 또는 지정 도서실이 진입공간과 직접 연계되는 계획이 이루어 져야 된다. 교육 및 연구 공간과 열람실이 유기적으로 연결되어야 함에 따라서 코어를 중심으로 교육 및 연구 공간과 열람실을 수직적으로 연계하여 열람실과 교육 연구 공간의 연계성을 높이는 동시에 외부에서의 접근성도 고려한 계획이 되어야한다.

• 한국생활과학회지
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• 제18권3호
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• pp.793-798
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• 2009

Hair cut is one of the best useful technical tool for hair styling. In this study using the rule of the layers of hair design, balanced for visual art, perceptual ability and form created by the principles of analysis and offer hair cuts and hair design of the representation of regions and even hair design as the basis of a student of Hair Beauty and all the people working in the field can create a variety of hair design puts the purpose to establish a basis. The result of this study can be outline as follows: First, the step line and the movement of the relationship between the law of the layers above and below the length of the same layer techniques, the same consists of a vertical cross-section of the overall round shape of the cut same layer is created and the appropriate volume and movement, the movement of low-layer round a little bit more feeling and expression is used when you want. High-layer used to want to move a lot of light and could see that. Second, the layer of the Law and over direction, lifting, section, the line control. weight control and analyzed by principle and the principle of the process of forming the written form was unknown. Third, hair design, the expansion of the expressive power of the law of the layers, and the section of the over direction depends on the presence of line control to express the length of the outline I had to, lifting the weight to adjust form controls, and the expression of Hair Design will be expanding the width. A hair designer, a layer style to create a zone he thought the law of the first layer formative area To further the reach will be a lot of research, leading up formative aspects of this research thesis do not have missing parts, or as a result of the Beauty of Hair Design and the width of a hair design education in the field can perform to help feed the reference materials that will be.

• International Journal of Aeronautical and Space Sciences
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• 제13권3호
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• pp.369-376
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• 2012

A nonlinear robust guidance law is designed for missiles against a maneuvering target by incorporating sliding-mode and optimal control theories based on the state dependent Riccati equation (SDRE) to achieve robustness against target accelerations. The guidance law is derived based on three-dimensional nonlinear engagement kinematics and its robustness against disturbances is proved by the second method of Lyapunov. A new switching surface is considered in the sliding-mode control design. The proposed guidance law requires the maximum value of the target maneuver, and therefore opposed to the conventional augmented proportional navigation guidance (APNG) law, complete information about the target maneuver is not necessary, and hence it is simple to implement in practical applications. Considering different types of target maneuvers, several scenario simulations are performed. Simulation results confirm that the proposed guidance law has much better robustness, faster convergence, and smaller final time and control effort in comparison to the sliding-mode guidance (SMG) and APNG laws.

• 한국안전학회지
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• 제33권4호
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• pp.54-61
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• 2018

Objective: The current study aimed to investigate the accessibility and usability of the disabled person while using the everyday facility. Background: The national laws regulated accommodation of persons with disabilities, but our knowledge on the practical usefulness of the laws and acceptance by the users is still far from complete. Method: Compliance with laws was checked throughout the actual measurement of 87 engineering designs in the facilities of a national university, and the practical usability of the facilities was investigated by in-depth interviews with eight disabled persons. New design solutions were developed by the anthropometric methodology for better accommodation. The target-specific anthropometry database such as sitting knee height with wheelchair was employed. Results: First, the statistic showed that 28.7% of facility designs comply with the law, 29.9% of facility designs doesn't comply with the law, and 41.4% of facility designs doesn't have related law or regulation. Second, the law of table height(71cm in current) can accommodate only 49.3% of wheelchaired population. The following test for 95% accommodation revealed that the table with 80cm high is required. Third, the current law in the door width(90cm) can only accommodate 82.6% of disabled persons, so the new design solution was calculated and suggested that 100cm in the door width is necessary for 99% accommodation of disabled persons. Conclusion: Even with the laws and regulations for the disabilities it was clear that the accessibility and usability of the disabled persons in everyday facilities was still limited. An investigation for the new solutions about a wide range of facilities is necessary for better practical accessibility and usability of the handicapped persons. Application: The results of current study can be a basement of developing a new guideline or regulation of the facility design for the disabled persons.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.1322-1325
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• 1997

A new feedback control law design techniqed usign of-off thrusters for the rotational maneuver of a flexible arm is discussed in this study. a two state on-off thruster actuator is taken as a primary actuation device for theis study. The on-off thruster operation is emulated in conjunction with the conventioal minimum-time trackig control law. The actuator input region is divided into two separate parts ; one is constant input and the other is time varying tegion. the new control law has potential applicatioin for the relatively low frequency structure such as large flexible space structure being currently used in various space echnology areas.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1430-1434
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• 2003

In this paper, for the fuzzy-reaching law method which has the characteristic of elimination of chattering at sliding mode as well as the characteristic of fast response at the design of variable structure controller with reaching law, optimal solutions for the determination of parameters of fuzzy membership functions by using genetic algorithm are proposed. Generally, the design of fuzzy controller has difficulties in determining the parameters of fuzzy membership functions by using a tedious trial-and-error process. To overcome these difficulties, this paper develops genetic algorithm of an optimal searching method based on genetic operation, and to verify the validity of this proposed method it is simulated through 2 link robot manipulator.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집A
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• pp.641-646
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• 2000

This paper addresses a throttle/brake control law for stop and go cruise control systems which make the vehicle remain at a safe distance from a preceding vehicle according to the driver's preference, automatically slow down and come to a full stop behind a preceding vehicle. The uncertainties of vehicle model have been considered in the design of the control law. The effect of throttle/brake control has been investigated via simulations. The simulations were performed using a complete nonlinear vehicle model. The results indicate that the proposed throttle/brake control law can provide the stop and go cruise control system with a good distance tracking performance.

• 제어로봇시스템학회논문지
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• 제7권7호
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• pp.574-581
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• 2001

In this paper we design and evaluate the longitudinal nonlinear N(aub)z-CSAS(Command and Stability Augmentation System) flight control law in \"DMI(Dynamic Model Inversion)-method\" and classical \"Gain Scheduling-method\", respectively, to meet the handling quality requirements associated with push-over pull-up maneuver. It is told that the flight control law designed in \"DM-method\" is adequate to the full flight regime without gain scheduling and is efficient to produce the time response shape desired to the handling quality requirements. On the contrary, the flight control law designed in \"Gain Scheduling-method\" is easy to be implemented in flight control computer and insensitive to variation of the actuator model characteristics.n of the actuator model characteristics.