• 대한기계학회논문집
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• 제19권1호
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• pp.181-192
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• 1995

In this study, we introduce new types of planar 2 degree-of-freedom robot modules resembling the musculoskeletal structure of the human arm with actuation redundancy. First, for the given actuator sizes the performance analysis for the manipulator with redundant actuation and without redundant actuation is performed with respect to maximum load handling capacity, maximum hand velocity, and maximum hand acceleration. Secondly an algorithm which decides optimal actuator sizes for the given operational performances is introduced, and the optimal actuator sizes for a robot module with four redundant actuation are obtained. The algorithms employed in this paper will be useful to analyze the robot performances and to determine the actuator sizes for general robot manipulators.

• Journal of Electrical Engineering and Technology
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• 제11권1호
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• pp.215-226
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• 2016

Modeling, control and implementation of a real redundant robot with five Degrees Freedom (DOF) of the SCARA (Selective Compliant Assembly Robot Arm) manipulator type is presented. Through geometric methods and structural and functional considerations, the inverse kinematics for redundant robot can be obtained. By means of a modification of the classical sliding mode control law through a hyperbolic function, we get a new algorithm which enables reducing the chattering effect of the real actuators, which together with the learning and adaptive controllers, is applied to the model and to the real robot. A simulation environment including the actuator dynamics is elaborated. A 5 DOF robot, a communication interface and a signal conditioning circuit are designed and implemented for feedback. Three control laws are executed in: a simulation structure (together with the dynamic model of the SCARA type redundant manipulator and the actuator dynamics) and a real redundant manipulator of the SCARA type carried out using MatLab/Simulink programming tools. The results, obtained through simulation and implementation, were represented by comparative curves and RMS indices of the joint errors, and they showed that the redundant manipulator, both in the simulation and the implementation, followed the test trajectory with less pronounced maximum errors using the adaptive controller than the other controllers, with more homogeneous motions of the manipulator.

• 한국신뢰성학회:학술대회논문집
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• 한국신뢰성학회 2000년도 춘계학술대회 발표논문집
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• pp.193-200
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• 2000

In this paper, we consider confidence limits for steady state availability of a redundant structure with the function of switchover processing. The system considered in this paper consists of three units which are an active unit, a standby unit and a switchover device. A control module does not affect the performance of the system while the active unit is operating but causes the system failure if the active unit fails at the failure of the control module. The effect of failure of control module is included in our reliability model of the simple redundant structure. The availability of the system is obtained by using the state space method. An example is given to illustrate our results.

• 로봇학회논문지
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• 제12권2호
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• pp.194-205
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• 2017

A redundantly actuated planar 3-degree-of-freedom parallel mechanism is analyzed to show its high application potential as a haptic device. Its structure along with the closed form forward position solutions is briefly discussed. Then its geometric and kinematic characteristics via singularity analysis, the kinematic isotropy index, and the input-output force transmission ratio are investigated both for the redundantly actuated cases and for the non-redundantly actuated case. In addition, comparative joint torque simulations of the mechanism with different number of redundant actuations as well as without redundant actuation are conducted to confirm the improved joint torque distribution characteristics. Through these analyses it is shown that the geometric and kinematic characteristics of the redundantly actuated mechanism are superior to the ones of the mechanism without redundant actuation. Thus, it can be concluded that the suggested planar mechanism with redundant actuation has a very high potential for haptic device applications.

• 한국정보통신학회논문지
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• 제7권1호
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• pp.122-128
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• 2003

In this paper, a 16${\times}$16-bit Multiplier and Accumulator (MAC) is designed using a Redundant Binary Adder (RBA) circuit so that it can make a fast addition of the Redundant Binary Partial Products (RB_PP's) by using Wallace-tree structure. Because a RBA adds two RB numbers, it acts as a 4-2 compressor, which reduces four inputs to two output signals. We propose a method to convert the Redundant Binary (RB) representation into the 2's complement binary representation. Instead of using the conventional full adders, a more efficient RB number to binary number converter can be designed with new conversion method.

• International Journal of Reliability and Applications
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• 제2권2호
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• pp.107-115
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• 2001

This paper considers some reliability indices, such as availability, average availability, reliability and steady state availability, of a redundant system with the function of switchover processing. We also derive the confidence limits for steady state availability of such system. The system, which is considered in this paper, consists of an active unit, a standby unit and a switchover device. In addition, the switchover processing is controlled by a control module. The effect of failure of the control module is taken into account to develop our reliability model for the redundant structure. Numerical examples are presented to illustrate our results.

• 한국실내디자인학회논문집
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• 제15권6호
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• pp.77-88
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• 2006

According to critics and architects, non-linear structure is not only an organic form of space, but also a form of space detached from modem style. Accordingly, non-linear structure can be accepted as an alternative to what has remained unsolved by deconstructionist. However, they are criticized for not clarifying the interdependent relationship between non-linearity of space and cognitive structure of human being. They ended up remaining the hypothesis just an intuitive and abstract one. This research began on the basis that their hypothesis is hard to be objectified, and it needs further inquiry. The purpose of this thesis is to explore how the redundant factors constitute non-linear structures of digital media centered space design. Geometric compositions of space structure were analyzed to define what types of redundant factors are contrived in the process of visual information. This study about the visual form, researching the Information Theory, and then offer a quantitative analysis that makes those more objective. Space structure and geometric composition were analyzed to define what types of redundancy are contrived in the process of visual information. In particular, I put higher theoretical emphasis on what characteristics are ensued in the process of structuring spaces than any other subjects. Followings are the conclusion of analysis. First, as a result of examining, we can assume that NOX' space structure is not a chaotic form, but has an operating the form of its own. Second, in case of curvilinear, the structure was found redundancy on mid deviation ratio and discontinuous circular fabric. Although most of their structures appeared complex with a higher coherent constant, they were found to be stable factors because of the low deviation ratio between systems. The amount of surplus information was stable structure as well.

• 한국항공우주학회지
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• 제37권6호
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• pp.595-601
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• 2009

높은 신뢰도를 요구하는 비행제어 시스템은 복잡한 중복구조로 구성된다. 이러한 중복 구조는 시스템의 내고장성(fault tolerant)을 향상시킬 수 있다. 따라서 시스템 설계자는 다양하게 구성될 수 있는 중복구조의 정량적 데이터를 바탕으로 적절한 구조를 선택할 수 있다. 본 논문에서는 중복구조의 특징을 분석하고 신뢰도 해석을 위해 필요한 수학적 모델을 정의하였다. 이렇게 정의된 해석 모델을 적용하여 Simulink 블록 기반의 Reliability Block Diagram 해석 도구를 구성하고, 상용으로 사용되고 있는 도구를 이용하여 분석도구의 타당성을 검증하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.1125-1128
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• 1998

A new architecture for high-speed implementation of adaptive decision-feedback equalizer (ADFE) applicable to wide-band digital wireless modems is described. Rather than using conventional two's complement arithmetic, a novel complex-valued filter structure is devised, which is based on redundant binary (RB) arithmetic. The proposed RB complex-valued filter reduces the critical path delay of ADFE, as well as leads to a more compact implementation than conventional methods. Also, the carry-propagation free (CPF) operation of the RB arithmetic enhances its speed. To demonstrate the proposed method, a prototype chip set is designed. They are designed to contain two complexvalued filter taps along with their coefficient updating circuits, and can be cascaded to implement loger filter taps for high bit-rate applications.

• Journal of Mechanical Science and Technology
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• 제19권spc1호
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• pp.320-327
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• 2005

A new mechanism for hyper redundant manipulator (HRM) is presented, which comprises of serially assembled compound three-bar linkages (CTL). The CTL mechanism has some unique properties. This paper presents the forward and inverse kinematics of this mechanism and shows the simulation of the HRM havig 9 CTL units. The recursive algorithm of the inverse kinematics that the author originally developed is employed. It is fast and stable ; moreover, it enables us to obtain a solution in which the end-point of the HRM is controlled by a portion of joints. It also presents the method of the dynamical analysis. There exist kinematical constraints in the proposed closed linkage mechanism. In the dynamic analysis constraints are sufficiently sustained by the constraint stabilization method that the author developed. The mechanical structure of the HRM having some CTL units that is under construction is shown.