• Title/Summary/Keyword: Arm structure

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The Effect of Information Technology on Arms-Length Buyer-Supplier Relationship

  • Kim, Soo-W.
    • International Journal of Quality Innovation
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    • v.9 no.3
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    • pp.57-69
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    • 2008
  • This paper posits that arm's length buyer-supplier relationship as the intermediate type between market exchange relations and strategic partnership might be advisable, and information technology may have a role as a mechanism actualizing the effects of such arm's length relationship by strategic supply-line diversification. Based on the theoretical analysis on interactive feedback relationships among IT level, buyer-supplier relationships, and supply chain structure, we suggest a set of advisable buyer-supplier relationship type for efficient supply chain management. Also, doing so would be helpful in suggesting a dynamic IT investment and adoption model appropriate for the establishment of productive buyer-supplier relationship, and further in providing theoretical foundations and practical guidelines on the role and function of B-to-B E-commerce for efficient SC integration.

Delamination analysis of inhomogeneous viscoelastic beam of rectangular section subjected to torsion

  • Victor I. Rizov
    • Coupled systems mechanics
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    • v.12 no.1
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    • pp.69-81
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    • 2023
  • This paper considers a delamination analysis of a statically undetermined inhomogeneous beam structure of rectangular section with viscoelastic behavior under torsion. The beam is built in at its two ends. The beam has two longitudinal inhomogeneous layers with a delamination crack between them. A notch is made in the upper crack arm. The external torsion moment applied on the beam is a function of time. Under these conditions, the beam has one degree of indeterminacy. In order to derive the strain energy release rate, first, the static indeterminacy is resolved. Then the strain energy release rate is obtained by analyzing the balance of the energy with considering the viscoelastic behavior. The strain energy release rate is found also by analyzing the compliance of the beam for checkup. Solution of the strain energy release rate in a beam without a notch in the upper crack arm is derived too. In this case, the beam has two degrees of static indeterminacy (the torsion moment in the upper crack arm is treated as an additional internal redundant unknown). A parametric investigation of the strain energy release rate is carried-out.

A Stydy on the Ergonomic Sleeve Design by Body Surface Changes at Upper Extremity (상지체표변화에 따른 인간공학적 소매설계에 관한 연구)

  • 최해주
    • Journal of the Korean Society of Clothing and Textiles
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    • v.19 no.6
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    • pp.911-923
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    • 1995
  • The zone of expansion and contraction of arm surfaces was analyzed, the correlation between arm surface changes was studied, and ergonomic sleeve designs were presented in which the consideration of body surface changes is emphasized. Experiments were carried out which include 43 upper extremity segments, 21 motions and 35 female subjects. The major conclusions of the study are as follows : 1. As a sleeve drafting method, detailed measures should be applied on the base of the sensitivity of body surface changes. The range of arm surface changes can be divided into three zones : concentrated expansion zone, zone of little change, and contraction part. The maximum expansion zone was the upper part of elbow. 2. The correlations were higher in lengths than in circumferences. Arm lengths were mainly correlated with upper arms. The more detailed the arm surface was, the lower the correlations between surface changes were. So there was not a lot of relation between segment changes. Tendency of body surface changes depended on the anatomical structure of the upper extremity and the movements of arm muscles. 3. As an application of measures and ease, ergonomic sleeve designs weve presented in which arm surface changes were considered. Ergonomic sleeve designs are recommended for working clothes and sports wear.

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Real-Time Fuzzy Control for Dual-Arm with 8 Joints Robot Using the DSPs(TMS320C80) (DSPs(TMS320C80)을 이용한 8축 듀얼 아암 로봇의 실시간 퍼지제어)

  • 한성현;김종수
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.13 no.1
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    • pp.35-47
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    • 2004
  • In this paper presents a new approach to the design and real-time implementation of fuzzy control system based-on digital signal processors(DSP:IMS320C80) in order to improve the precision and robustness for system of industrial robot(Dual-Arm with 8 joint Robot). The need to meet demanding control requirement in increasingly complex dynamical control systems under significant uncertainties, leads toward design of intelligent manipulation robots. The IMS320C80 is used in implementing real time fuzzy control to provide an enhanced motion control for robot manipulators. In this paper, a Self-Organizing Fuzzy Controller(SOFC) for the industrial robot manipulator with a actuator located at the base is studied. A fuzzy logic composed of linguistic conditional statements is employed by defining the relations of input-output variables of the controller. In the synthesis of a FLC(Fuzzy Logic Controller), one of the most difficult problems is the determination of linguistic control rules from the human operators. To overcome this difficult SOFC is proposed for a hierarchical control structure consisting of basic and high levels that modify control rules. The proposed SOFC scheme is simple in structure, Int in computation, and suitable for implementation of real-time control. Performance of the SOFC is illustrated by simulation and experimental results for a Dual-Arm robot with eight joints.

Shape Optimization of the Lower Control Arm using the Characteristic Function and the Fatigue Analysis (특성함수와 피로해석을 이용한 로워컨트롤암의 형상최적설계)

  • Park Youngchul;Lee Donghwa
    • Transactions of the Korean Society of Automotive Engineers
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    • v.13 no.1
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    • pp.119-125
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    • 2005
  • The current automotive is seeking the improvement of performance, the prevention of environmental pollution and the saving of energy resources according to miniaturization and lightweight of the components. And the variance analysis on the basis of structure analysis and DOE is applied to the lower control am. We have proposed a statistical design model to evaluate the effect of structural modification by performing the practical multi-objective optimization considering weight, stress and fatigue lift. The lower control arm is performed the fatigue analysis using the load history of real road test. The design model is determined using the optimization of acquired load history with the fatigue characteristic. The characteristic function is made use of the optimization according to fatigue characteristics to consider constrained function in the optimization of DOE. The structure optimization of a lower control arm according to fatigue characteristics is performed. And the optimized design variable is D=47 m, T=36mm, W=12 mm. In the real engineering problem of considering many objective functions, the multi-objective optimization process using the mathematical programming and the characteristic function is derived an useful design solution.

Topology Optimization of a HDD Actuator Arm

  • Chang, Su-Young;Cho, Ji-Hyon;Youn, Sung-Kie;Kim, Cheol-Soon;Oh, Dong-Ho
    • Computational Structural Engineering : An International Journal
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    • v.1 no.2
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    • pp.89-96
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    • 2001
  • A study on the topology optimization of a Hard-Disk-Driver(HDD) actuator arm is presented. The purpose of the present wert is to increase the natural frequency of tole first lateral mode of the HDD actuator arm under the constraint of total moment of inertia, so as to facilitate the position control of the high speed actuator arm. The first lateral mode is an important factor in the position control process. Thus the topology optimization for 2-D model of the HDD actuator arm is considered. A new objective function corresponding to multieigenvalue optimization is suggested to improve the solution of the eigenvalue optimization problem. The material density of the structure is treated as the design variable and the intermediate density is penalized. The effects of different element types and material property functions on the final topology are studied. When the problem is discretized using 8-node element of a uniform density, tole smoothly-varying density field is obtained without checker-board patterns incurred. AS a result of 7he study, an improved design of the HDD actuator arm is suggested. Dynamic characteristics of the suggested design are compared computationally with those of the old design. With the same amount of the moment of inertia, the natural frequency of the first lateral mode of the suggested design is subsequently increased over the existing one.

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Deterministic Nonlinear Control of Two-Link Flexible Arm (2관절 유연한 로봇 팔에 대한 비선형 제어)

  • Han, Jong-Kil;Son, Yong-Su
    • The Journal of the Korea institute of electronic communication sciences
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    • v.4 no.3
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    • pp.236-242
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    • 2009
  • When two-link flexible arm is rotated about an joint axis, transverse vibration may occur. In this paper, vibration dynamics of flexible robot arm is modeled by using Bernoulli-Euler beam theory and Lagrange equation. Using the fact that matrix $\dot{D}$-2C is skew symmetric, new controllers which have a simplified structure with less computational burden is proposed. Lyapunov stability theory is applied to achieve a stable deterministic nonlinear controller for the regulation of joint angle.

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Optimal Design of Slim TV Wall Mount Arm with Cantilever Structure (외팔보 구조의 슬림형 TV 월마운트암의 최적설계)

  • Jang, Woon-Geun
    • Journal of the Korean Society of Industry Convergence
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    • v.14 no.4
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    • pp.167-172
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    • 2011
  • This paper investigated optimal design for slim wall mount arm for flat TV. Recently the number of flat TV sets in use went on increasing in TV market. As the flat TV sets are getting common, consumers came to need another requirements like aesthetic factor besides display performances. As the new TV sets tend to be slimmer due to aesthetic design, Wall mount also requires to be slimmer for aesthetic balance. Slim structures, however, are vulnerable to structural rigidity. In this study, slim wall mount arm has been designed by 3D CAD and DOE (Design of Experiments) and finite element analysis for optimal structural design were carried out to determine the design variables for minimize working stress of wall mount arm. Finally two optimal design conditions were selected through DOE and FEM and one of those was chosen under constraint of minimizing blanking developed length.

Tip Position Control of Flexible Robot Manipulators Using 2-DOF Controller with Sliding Mode (슬라이딩 모드를 가진 2-자유도 제어기를 이용한 유연한 로봇 조작기의 끝점 위치 제어)

  • 신효필;이종광;강이석
    • Journal of Institute of Control, Robotics and Systems
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    • v.6 no.6
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    • pp.471-477
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    • 2000
  • The position control accuracy of a robot arm is significantly deteriorated when a long arm robot is operated at a high speed. In this case, the robot arm must be modeled as a flexible structure, not a rigid one, and its control system should be designed with its elastic modes taken into account. In this paper, the tip position control scheme of a one-link flexible manipulator using 2-DOF controller with sliding mode is presented. The robot consists of a flexible arm manufactured with a thin aluminium plate, an AC servo motor with a harmonic drive for speed reduction, an optical encoder and a CCD camera as a vision sensor for on-line measuring the tip deflection of the flexible m. Simulation and experimental results of the flexible manipulator with a proposed controller are provided to show the effectiveness of the controller.

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