• 제목/요약/키워드: Use of force

검색결과 2,230건 처리시간 0.027초

조화력에 의한 원환의 강제진동 (Forced Vibration of a Circular Ring with Harmonic Force)

  • 홍진선
    • 한국소음진동공학회논문집
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    • 제15권2호
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    • pp.123-128
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    • 2005
  • Forced vibration of a thin circular ring with a concentrated harmonic force is analyzed when the ring is free and has only the in-plane motion. Using the unit doublet function for external force, the governing equation is obtained and is solved by the use of Laplace transform. The exact solutions of displacement components and bending moment are obtained. In order to verify the solutions of analysis, finite element analysis is performed and the results shows good agreement. Then, frequency response curves for displacement and bending moment are obtained. In deriving the governing equations and the solutions, nondimensional parameter of the exciting frequency and the magnitude of exciting force are extracted. As the displacement components are obtained, the remaining bending strain, slope, curvature, shear force, etc. can also be derived. With the results of this work, the responses of a free ring excited on multiple points with different frequencies can also be obtained easily by superposition.

DC 편의된 다상 입력을 이용한 횡자속 선형 유도 전동기의 부상/추진 독립제어 (Decoupling Control of Levitation and Thrust Motion of The Transverse Flux Linear Induction Motor Using DC-biased Multi Phase Inputs)

  • 정광석;허진혁;백윤수
    • 대한기계학회논문집A
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    • 제28권11호
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    • pp.1733-1740
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    • 2004
  • In the transverse flux linear induction motor(TFLIM) with the general secondary composed of conductor and back-yoke, there exists a magnetized force into the normal direction or the air-gap direction of the thrust motion as well as the thrust force. Therefore, the various methodologies have been tried to use the normal force by the two independent control variables of the multi-phase input. But, as the force depends inevitably and strongly on the thrust force, it is essential to decouple both forces for two control index. In this paper, we suggest a novel approach capable of compensating the couple between both forces and the control index by using the DC-biased multi-phase input, and then realizing the independent control of TFLIM.

Human sensory feedback research in the armstrong laboratory

  • Weisenberger, Janet M.
    • 대한인간공학회지
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    • 제16권2호
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    • pp.83-100
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    • 1997
  • The Human Sensory Feedback Laboratory, park of the Armstrong Laboratory at Wright-Patterson Air Force Base, Ohio, is involved in the development and evaluation of systems that provide sensory feedback to the human operator in telerobotic and virtual environment applications. Specific projects underway in the laboratory are primarily concerned with the information provided by force and vibrotactile feedback to the operator in dextrous manipulation tasks. Four specific research projects are described in the present report. These include : 1) experiments evaluating a 30-element fingertip display, which employs a titanium-nickel shape memory alloy actuator design to provide vibrotactile feedback about object shape and surface texture ; 2) of a fingertip force-feedback display for 3-dimensional information about object shape and suface texture ; 3) use of a force- feedback joystic to provide "force tunnel" information in pilot pursuit tracking tasks ; and 4) evaluations of a 7 degree-of-freedom exoskeleton used to control a robotic arm. Both basic and applied research questions are discussed.

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근전도신호의 패턴인식 및 힘추정을 통한 의수의 지능적 궤적제어에 관한 연구 (A Study on Intelligent Trajectory Control for Prosthetic Arm by Pattern Recognition & Force Estimation Using EMG Signals)

  • 장영건;홍승홍
    • 대한의용생체공학회:의공학회지
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    • 제15권4호
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    • pp.455-464
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    • 1994
  • The intelligent trajectory control method that controls moving direction and average velocity for a prosthetic arm is proposed by pattern recognition and force estimations using EMG signals. Also, we propose the real time trajectory planning method which generates continuous accelleration paths using 3 stage linear filters to minimize the impact to human body induced by arm motions and to reduce the muscle fatigue. We use combination of MLP and fuzzy filter for pattern recognition to estimate the direction of a muscle and Hogan's method for the force estimation. EMG signals are acquired by using a amputation simulator and 2 dimensional joystick motion. The simulation results of proposed prosthetic arm control system using the EMG signals show that the arm is effectively followed the desired trajectory depended on estimated force and direction of muscle movements.

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횡력발생 코일스프링 설계 및 제조에 관한 연구 (A Study on the Development of the Side Load Coil Spring)

  • 권혁홍;최선준
    • 한국생산제조학회지
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    • 제7권5호
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    • pp.98-105
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    • 1998
  • In the automotive suspension system, especially, Mcpherson strut type, if the resultant of the force through tire and the link reaction force is not coincident with the spring force, the side load against shock-absorber occur. The magnitude of side load is proportional to the difference between resultant force and spring force. To reduce side load, several method can be used, and one is to use the side load coil spring. This study summarize the development results of side load coil spring, i.e., how to design, analysis, manufacture, and test.

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주기적인 마찰력을 받는 드럼-브레이크 슈의 동적안정성 (Dynamic Stability of a Drum-brake Shoe Under a Pulsating Frictional Force)

  • 류봉조;오부진;임경빈;김효준
    • 한국소음진동공학회논문집
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    • 제12권11호
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    • pp.890-896
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    • 2002
  • This paper deals with the dynamic stability of a brake shoe under pulsating frictional forces. A lining part of brake systems is assumed as a distributed spring, and the supported elements of a shoe are assumed as translational springs for a constant distributed frictional force and a pulsating frictional force. Governing equations are derived by the use of the extended Hamilton's principle, and numerical results are calculated by finite element method. The critical distributed frictional force and instability regions were investigated for the change of distributed spring constants and translational spring constants.

온도 변화에 따른 드릴가공의 절삭력 변화와 가공정밀도 평가 (Evaluation of Cutting force and Surface accuracy on Drilling process by Temperature variation)

  • 이상천;정우섭;백인환
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1997년도 추계학술대회 논문집
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    • pp.895-898
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    • 1997
  • These days, most of new materials, which is in use widely as cutting process materials have a characteristic in common. That is hard cutting. So, it happens that hardness by cutting temperature. And hardness on cutting process has an effect on tool wear or life shortness of tools. To solve these problems hot-machining is proposed. When a material is heated, organization of material is soften. So cutting process becomes easy. When such a hot-machining method applies on drilling process and then heated material is processed, cutting force is less than usual drilling process cutting force. In this paper, when a material is heated, cutting force on drilling process is measured. It is decided that the best suitable temperature area. And it suggest that the better hot-machining condition as surface accuracy is measured.

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밀링공정중 절삭조건 변화에 따른 절삭력 추종제어를 위한 DSP보드 응용 (DPS Board Appication for Regulation of Cutting Force under Varying Cutting Conditions during Milling Process)

  • 오영탁;권원태;주종남
    • 한국정밀공학회지
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    • 제16권3호통권96호
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    • pp.38-46
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    • 1999
  • Spindle motor current is used to estimate the cutting force indirectly and control the feed rate for the cutting force regulation. The proposed algorithm is implemented to a DSP board based hardware for the industrial application. The software to make POP terminal communicate with the DSP board and POP server is coded under Windows 95 environment. Experiments under varying cutting conditions show that the DSP board recognizes the information of installed cutting tool and cutting conditions delivered from the POP server to use them for the proper control of the feed rate. The cutting force is regulated well during machining of tapered or stepped workpiece and circular shaped workpiece as well.

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4축 구동 유압실린더-클램핑 부하 시스템의 힘 동기제어 (Force Synchronizing Control for 4 Axes Driven Hydraulic Cylinder-Clamping Load Systems)

  • 조승호
    • 드라이브 ㆍ 컨트롤
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    • 제11권2호
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    • pp.9-15
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    • 2014
  • This paper deals with the issue of force synchronizing control for the clamping servomechanism of injection molding machines. Prior to the controller design, a virtual design model has been developed for the clamping mechanism with hydraulic systems. Then, a synchronizing controller is designed and combined with an adaptive feedforward control in order to accommodate the mismatches between the real plant and the linear model plant used. As a disturbance, the leakage due to the ring gap with relative motion in the cylinder has been introduced. From the robust force tracking simulations, it is shown that a significant reduction in the force synchronizing error is achieved through the use of a proposed control scheme.

센서리스 협동로봇의 직관적인 교시를 위한 직교공간 직접교시 (Cartesian Space Direct Teaching for Intuitive Teaching of a Sensorless Collaborative Robot)

  • 안국현;송재복
    • 로봇학회논문지
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    • 제14권4호
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    • pp.311-317
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    • 2019
  • Direct teaching is an essential function for collaborative robots for easy use by non-experts. For most robots, direct teaching is implemented only in joint space because the realization of Cartesian space direct teaching, in which the orientation of the end-effector is fixed while teaching, requires a measurement of the end-effector force. Thus, it is limited to the robots that are equipped with an expensive force/torque sensor. This study presents a Cartesian space direct teaching method for torque-controlled collaborative robots without either a force/torque sensor or joint torque sensors. The force exerted to the end-effector is obtained from the external torque which is estimated by the disturbance observer-based approach with the friction model. The friction model and the estimated end-effector force were experimentally verified using the robot equipped with joint torque sensors in order to compare the proposed sensorless approach with the method using torque sensors.