• Title/Summary/Keyword: compliant

Search Result 624, Processing Time 0.074 seconds

Radiated Sound from Compliant and Viscoelastic Plates in a Turbulent Boundary Layer (난류 경계층에서 컴플라이언트 코팅과 점탄성 벽면의 방사 소음에 관한 실험적 연구)

  • Lee Seungbae;Lee Chang-Jun;Kwon O-Sup;Jeon Woo-Pyung
    • Proceedings of the KSME Conference
    • /
    • 2002.08a
    • /
    • pp.779-782
    • /
    • 2002
  • We examine the problem in which porous/viscoelastic compliant thin plates are subject to pressure fluctuations under transitional or turbulent boundary layer. Measurements are presented of the frequency spectra of the near-field pressure and radiated sound by compliant surface. A porous plate consisting of 5mm thick, open-cell foam with fabric covering and a viscoelastic painted plate of 1mm thick over an acoustic board of 4m thick were placed over a rigid surface in an anechoic wind tunnel. Streamwise velocity and wall pressure measurements were shown to highly attenuate the convective wall pressure energy when the convective wavenumber ($k_{ch}$) was 3.0 or more. The sound source localization on the compliant walls is applied to the measurement of radiated sound by using an acoustic mirror system.

  • PDF

Adaptive compliant control for scara manipulator

  • Yee, Yanghyi;Ka, Minho;Kim, Sungwoo;Park, Mignon;Lee, Sangbae
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1990.10b
    • /
    • pp.1322-1326
    • /
    • 1990
  • In this paper, compliant motion control of a manipualator in manipulator is proposed by using the self-tuning adaptive controller. Compliant motion is needed in order to applicated to complicated and accurate fields such as assembly operation in which several parts are matched. For a control method of compliant motion hybrid control is used so forces and position control are proposed selectively through a closed feedback loop. By contacting with environment, the uncertainties higher. Self-tuning controller which adapts to variable dynamic response is applied to compliant motion control in order to satisfy the desired operation. The applicability of the suggested algorithm was confirmed by simulation of the contour tracking task of four joint manipulator.

  • PDF

Radiated Sound from Compliant and Viscoelastic Plates in a Turbulent Boundary Layer (난류 경계층에서 컴플라이언트 코팅된 벽면과 점탄성 벽면의 방사 소음에 관한 실험적 연구)

  • Lee, Chang-Jun;Lee, Seung-Bae;Kwon, O-Sup;Jun, Woo-Pyung
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.27 no.3
    • /
    • pp.294-301
    • /
    • 2003
  • We examine a problem in which porous/viscoelastic compliant thin plates are subject to pressure fluctuations under transitional or turbulent boundary layer. Measurements are presented of the frequency spectra of the near-field pressure and radiated sound by compliant surface. A porous plate consisting of 5mm thick. open-cell foam with fabric covering and a viscoelastic-painted plate of 1mm thick over an acoustic board of 4mm thick were placed over a rigid surface in an anechoic wind tunnel. Streamwise velocity and wall pressure measurements were shown to highly attenuate the convective wall pressure energy when the convective wavenumber (k$_{c}$h) was 3.0 or more. The sound source localization on the compliant walls is applied to the measurement of radiated sound by using an acoustic mirror system.

Reliability Based Topology Optimization of Compliant Mechanisms (컴플라이언트 메커니즘의 신뢰성 기반 위상최적설계)

  • Im, Min-Gyu;Park, Jae-Yong;Han, Seog-Young
    • Journal of the Korean Society of Manufacturing Technology Engineers
    • /
    • v.19 no.6
    • /
    • pp.826-833
    • /
    • 2010
  • Electric-thermal-structural actuated compliant mechanisms are mechanisms onto which electric voltage drop is applied as input instead of force. This mechanism is based on thermal expansion of material while being heated. Compliant mechanisms are designed subjected to electric charge input using BESO(bi-directional evolutionary structural optimization) method. Reliability-based topology optimization (RBTO) is applied to the topology design of actuators. performance measure approach (PMA), which has probabilistic constraints that are formulated in terms of the reliability index, is adopted to evaluate the probabilistic constraints. In this study, BESO method is used to obtain optimal topology of compliant mechanisms from initial design domain. PMA approach is used to evaluate reliability index. The procedure has been tested in numerical applications and compared with the results obtained by other methods to validate these approaches.

Kinestatic Control using a Compliant Device by Fuzzy Logic (퍼지 논리에 의한 순응기구의 위치/힘 동시제어)

  • Seo, Jeong-Wook;Choi, Yong-Je
    • Proceedings of the KSME Conference
    • /
    • 2004.04a
    • /
    • pp.917-922
    • /
    • 2004
  • As the tasks of robots become more diverse, some complicated tasks have come to require force and position hybrid control. A compliant device can be used to control force and position simultaneously by separating the twist of the robot's end effector from the twist of compliance and freedom by using stiffness mapping of the compliant device. The development of a fuzzy gain scheduling scheme of control for a robot with a compliant device is described in this paper. Fuzzy rules and reasoning are performed on-line to determine the gain of twists based on wrench error and twist error and twist of compliance and twist of freedom ratio. Simulation results demonstrate that better control performance can be achieved in comparison with constant gain control.

  • PDF

3-DOF Parallel Micromanipulator : Design Consideration (3차원 평형 마이크로조정장치 : 설계 고려사항)

  • Lee, Jeong-Ick;Lee, Dong-Chan;Han, Chang-Soo
    • Transactions of the Korean Society of Machine Tool Engineers
    • /
    • v.17 no.2
    • /
    • pp.13-22
    • /
    • 2008
  • For the accuracy correction of the micro-positioning industrial robot, micro-manipulator has been devised. The compliant mechanisms using piezoelectric actuators is necessary geometrically and structurally to be developed by the optimization approaches. The overall geometric advantage as the mechanical efficiencies of the mechanism are considered as objective functions, which respectively art the ratio of output displacement to input force, and their constraints are the vertical notion of supporting leg and the structural strength of manipulation. In optimizing the compliant mechanical amplifier, the sequential linear programming and an optimality criteria method are used for the geometrical dimensions of compliant bridges and flexure hinges. This paper presents the integrated design process which not only can maximize the mechanism feasibilities but also can ensure the positioning accuracy and sufficient workspace. Experiment and simulation are presented for validating the design process through the comparisons of the kinematical and structural performances.

Topology Optimization of Thermal Actuated Compliant Mechanisms (열 컴플라이언트 메커니즘의 위상 최적설계)

  • Lee, Won-Gu;Im, Min-Gyu;Park, Jae-Yong;Han, Seog-Young
    • Journal of the Korean Society of Manufacturing Technology Engineers
    • /
    • v.19 no.4
    • /
    • pp.434-439
    • /
    • 2010
  • A compliant mechanism is a mechanism that produces its motion by the flexibility of some or all of its members when input force or thermal load is applied. Whereas the topology optimizations based on homogenization and SIMP parameterization have been successfully applied for compliant mechanism design, ESO approach has been hardly considered yet for the optimization of these types of systems. In this paper, traditional ESO method is adopted to achieve the optimum design of a compliant mechanism for thermal load, since AESO method cannot consider the effect of both heat conduction and convection. Sensitivity number, a criterion for element removal in traditional ESO, was newly defined for input thermal loading. The procedure has been tested in numerical applications and compared with the results obtained by other methods to validate these approaches.

Task-Based Analysis on Number of Robotic Fingers for Compliant Manipulations

  • Kim, Byoung-Ho
    • International Journal of Fuzzy Logic and Intelligent Systems
    • /
    • v.9 no.4
    • /
    • pp.333-338
    • /
    • 2009
  • This paper presents a task-based analysis on the number of independent robotic fingers required for compliant manipulations. Based on the stiffness relation between operational space and fingertip space of a multi-fingered object manipulating system, we describe a technique for modulation of the fingertip stiffness without inter-finger coupling so as to achieve the desired stiffness specified in the operational space. Thus, we provides a guide line how many fingers are basically required for successful multi-fingered compliant tasks. Consequently, this paper enables us to assign effectively the number of fingers for various compliant manipulations by robot hands.

Factors Influencing Corporate Donations Among Shariah-Compliant Companies in Malaysia

  • SHAARI, Nur Diyana Izzati Mohamed;ALI, Mazurina Mohd;HASNAN, Suhaily;AHMAD, Nassr Saleh Mohamad
    • The Journal of Asian Finance, Economics and Business
    • /
    • v.10 no.1
    • /
    • pp.145-156
    • /
    • 2023
  • Within the context of publicly traded Sharia-compliant companies in Malaysia, this study investigated the influence that board and company characteristics have on corporate donations. The primary focus of the study was (i) two board characteristics derived from upper echelons theory, namely gender composition and education level, and (ii) four firm variables derived from stakeholder theory, specifically company size, profitability, leverage, and industry category. This study used a total of 402 Shariah-compliant companies that operated in accordance with Shariah law. The information utilized in this study was culled by hand from the annual reports of various companies covering the years 2017 through 2019. According to the findings, the educational level of a company's board of directors has a significant impact on the amount of money donated to charitable organizations by Shariah-compliant companies. The level of expertise possessed by board members can be of assistance to businesses in becoming more aware of the necessity of making contributions or donations. Corporate contribution practices among Shariah-compliant companies in Malaysia were also significantly influenced by the firm's size, profitability, and the industry category in which the business was classified. The findings of the study contribute to a better understanding of the impact that board and company variables have on the activities of corporate donors.

A retrospective study on patients' compliance with supportive periodontal therapy (유지치주치료의 환자 순응도해 대한 후향적 연구)

  • Park, Woong-Kyu;Lee, Jae-Kwan;Chang, Beom-Seok;Um, Heung-Sik
    • Journal of Periodontal and Implant Science
    • /
    • v.39 no.1
    • /
    • pp.59-70
    • /
    • 2009
  • Purpose: The purpose of this study was to investigate the degree of compliance with supportive periodontal therapy(SPT), to determine if any significant differences existed in the characteristics of compliant, erratically compliant and non-compliant patients and to identify reasons for poor compliance. Materials and methods: Four hundred five patients who initially visited between July 2003 and December 2004 and were treated until June 2005 were retrospectively evaluated for their compliance with SPT in terms of attendance for a recommended schedule of visits. Patients' compliance was classified as complete compliance(attended more than 80% of the recommended appointments), erratic compliance(attended less than 80% of the recommended appointments or discontinued) and non-compliance(did not return for SPT). Analysis was made for each group to correlate the degree of compliance with gender, age, smoking, distance between their houses and the hospital, disease severity, type of therapy, implant, plaque control instruction and systemic diseases. Tele research of erratically compliant and non-compliant patients was carried out to identify reasons for their poor compliance. Results: Only 24.7% of the patients were in complete compliance. The highest drop-out rate(32.4%) occurred in the first year. A significantly greater percentage of non-smokers and patients who finished plaque control instruction were in complete compliance. A significantly greater percentage of patients without implant and patients who had been treated by only scaling and root planing were in non-compliance. More males were found to be compliant with SPT, although this was marginally significant. There were no significant differences between compliant, erratically compliant and non-compliant patients with regard to age, distance, disease severity and systemic disease. The survey revealed that the main reasons for poor compliance with SPT were inconvenient location and insufficient time. Conclusion: Patients' compliance with SPT was poor and the highest drop-out rate(32.4%) occurred in the first year. Significant relationships were found between the degree of compliance and smoking, type of therapy, implant, plaque control instruction and gender.