• Title/Summary/Keyword: redundant

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Sizing, geometry and topology optimization of trusses using force method and supervised charged system search

  • Kaveh, A.;Ahmadi, B.
    • Structural Engineering and Mechanics
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    • v.50 no.3
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    • pp.365-382
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    • 2014
  • In this article, the force method and Charged System Search (CSS) algorithm are used for the analysis and optimal design of truss structures. The CSS algorithm is employed as the optimization tool and the force method is utilized for analysis. In this paper in addition to member's cross sections, redundant forces, geometry and topology variables are considered as the optimization variables. Minimum complementary energy principle is used directly to analyze the structure. In the presented method, redundant forces are calculated by the CSS in order to minimize the energy function. Combination of the CSS and force method leads to an efficient algorithm in comparison to some of the optimization algorithms.

Design of Auditory Icons in Mobile Applications (모바일제품을 위한 청각 아이콘 설계에 관한 연구)

  • Park, Dong-Hyun;Myung, Ro-Hae
    • Journal of the Ergonomics Society of Korea
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    • v.24 no.3
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    • pp.29-34
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    • 2005
  • Little research has been performed regarding auditory icons even though auditory icons have great potentials as a strategy for creating informative, intuitively accessible, and unobtrusive interface. Therefore, this study was conducted to design new auditory icons through the iconic mapping for ten most frequently used mobile phone menus, and to show the usability of auditory icons. Two most familiar auditory sounds for each menu were collected and compared to the current button-pressing sound. The results show that the newly designed auditory icons had shorter recognition times, better satisfaction than the current icons. In other words, auditory icons could be an effective interface to provide a redundant feedback along with visual feedbacks in navigating mobile devices.

Resolution of kinematic redundancy using contrained optimization techniques under kinematic inequality contraints

  • Park, Ki-Cheol;Chang, Pyung-Hun
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10a
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    • pp.69-72
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    • 1996
  • This paper considers a global resolution of kinematic redundancy under inequality constraints as a constrained optimal control. In this formulation, joint limits and obstacles are regarded as state variable inequality constraints, and joint velocity limits as control variable inequality constraints. Necessary and sufficient conditions are derived by using Pontryagin's minimum principle and penalty function method. These conditions leads to a two-point boundary-value problem (TPBVP) with natural, periodic and inequality boundary conditions. In order to solve the TPBVP and to find a global minimum, a numerical algorithm, named two-stage algorithm, is presented. Given initial joint pose, the first stage finds the optimal joint trajectory and its corresponding minimum performance cost. The second stage searches for the optimal initial joint pose with globally minimum cost in the self-motion manifold. The effectiveness of the proposed algorithm is demonstrated through a simulation with a 3-dof planar redundant manipulator.

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Impedance modulation of anthropomorphic robots with kinematic and force redundancies (여유자유도/여유구동 인체형 로봇의 임피던스 생성방식)

  • 이병주;김희국;이재훈
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.1289-1292
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    • 1997
  • Typical biomechanical system such as human body and mammals possess abundant muscles which are more than required for motion generation of such systems. We have shown that the excess number of muscles play important roles in spring-like impedance modulation. redundant kinematic structure, which is another feature of biomechanical systems, allows modulations of inertia and damping properties of such systems. In this work, we propose a frequency modulation algorithm which combines the spring-like impedance with inertia impedance. also, a load distribution method for frequency modulation is also introduced. The frequency modulation represents a simulataneous control of force and kinematic redundancies, which has not been addressed in the literature.

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Kinematic/dynamic modeling and analysis of a 3 degree-of-freedom redundantly actuated mobile robot (세바퀴 여유구동 모바일 로봇의 기구학/동력학 모델링 및 해석)

  • Park, Seung;Lee, Byung-Joo;Kim, Hee-Gook
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.528-531
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    • 1997
  • This paper deals with the kinematic and dynamic modeling of a 3 degree-of-freedom redundantly actuated mobile robot for the purpose of analysis and control. Each wheel is driven by two motors for steering and driving. Therefore, the system becomes force-redundant since the number of input variable is greater than the number of output variable. The kinematic and dynamic models in terms of three independent joint variables are derived. Also, a load distribution method to determine the input loads is introduced. Finally we demonstrate the feasibility of the proposed algorithms through simulation.

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Analysis of Weightlifting Motion Based on Robotic Manipulability (로봇 조작도에 기반한 역도 들기 자세 해석)

  • Won, Kyoung-Tae;Lee, Ji-Hong
    • Journal of Institute of Control, Robotics and Systems
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    • v.5 no.4
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    • pp.446-453
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    • 1999
  • An athlete motion during weightlifting is analyzed based on robotic manipulability, which shows dexterities by changing the position and orientation of the end-effector of robot manipulators arbitrary or along a specified direction. The athlete body is modeled as a highly redundant robot manipulator. The motion of weightlifting is analyzed based on the selected model with a power manipulability. Power manipulability and its geometric characteristics are derived by combining kinematic manipulability and dynamic manipulability. Also, manipulability-based optimal trajectory of weightlifter for given body structure of weightlifter derived through genetic algorithm.

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Study on redundancy resolution algorithm of humanoid

  • Yoo, Dong-Su;So, Byung-Rok;Choi, Jae-Yeon;Yi, Byung-Ju;Kim, Whee-Kuk
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.2759-2764
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    • 2003
  • Humans usually employ more joints than they actually need, and thus they can be categorized as a kinematically redundant system. Therefore, the behavior of the human body can be analyzed by several redundancy resolution algorithms. Different from typical industrial robots that are fixed to the ground, the COG/ZMP condition should be taken into account in the human body motion in order not to fall down. Thus a COG/ZMP stability index is employed as a measure of stability. Kinematic redundancy inherent in the human body can be exploited to satisfy the COG/ZMP condition. Simulation result shows that the COG/ZMP condition can be satisfied by exploiting the null space motion of the kinematically redundant human body model.

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Long-Term Behavior of Composite Continuous Beams With Flexible Shear Connectors (슬립을 고려한 강합성 연속보의 장기거동해석)

  • 최동호;김호배;이동혁;고상은
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2000.04b
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    • pp.141-149
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    • 2000
  • This study performs the elastic and viscoelastic analysis of composite continuous beams with flexible shear connectors. Due to creep and shrinkage of the concrete part, the stress redistribution between the concrete slab and steel beam, and the evolution of the redundant restraint reaction occur with time. Using the equation of equilibrium, internal and external compatibility condition, and constitutive relationships, mathematical formulations are formulated. The solution is obtained by means of numerical step-by-step techniques and the finite difference method. Numerical parametric studies are performed to evaluate the stress redistribution, and the evolution of the redundant restraint reaction. The parameters include the stiffness and spacing of shear connectors, the age of concrete at loading, and the relative humidity.

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