• 제목/요약/키워드: Precision Position Control

검색결과 741건 처리시간 0.029초

다이아몬드 터닝 머시인의 극초정밀 절삭공정에서의 시스템 규명 및 제어 (System identification and admittance model-based nanodynamic control of ultra-precision cutting process)

  • 정상화;김상석;오용훈
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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    • pp.1352-1355
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    • 1996
  • The control of diamond turning is usually achieved through a laser-interferometer feedback of slide position. If the tool post is rigid and the material removal process is relatively static, then such a non-collocated position feedback control scheme may surface. However, as the accuracy requirement gets tighter and desired surface contours become more complex, the need for a direct tool-tip sensing becomes inevitable. The physical constraints of the machining process prohibit any reasonable implementation of a tool-tip motion measurement. It is proposed that the measured force normal to the face of the workpiece can be filtered through an appropriate admittance transfer function to result in the estimated depth of cut. This can be compared to the desired depth of cut to generate the adjustment control action in addition to position feedback control. In this work, the design methodology on the admittance model-based control with a conventional controller is presented. The recursive least-squares algorithm with forgetting factor is proposed to identify the parameters and update the cutting process in real time. The normal cutting forces are measured to identify the cutting dynamics in the real diamond turning process using the precision dynamometer. Based on the parameter estimation of cutting dynamics and the admittance model-based nanodynamic control scheme, simulation results are shown.

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한 쌍의 6축 전기유압 매니퓰레이터의 힘제어 (Force Control of one pair of 6-Link Electro-Hydraulic Manipulators)

  • 안경관;조용래;양순용;이병룡
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1997년도 추계학술대회 논문집
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    • pp.353-356
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    • 1997
  • Hydraulically driven manipulators are superior to electrically driven ones in the power density and electrical insulation. But an electro-hydraulic manipulator using hydraulic actuators has many nonlinear elements, and this parameter fluctuations are greater than those of electrically driven manipulator. So this is relatively difficult to realize not only stable contact work but also accurate force control for the autonomous field task such as the maintenance task of high voltage active electric line or the automatic excavation task by hydraulic excavator. In this report, we propose robust force control algorithm, which can be applied to there real field task such as the construction field, nuclear plant and so on. Proposed force controller has the same structure as that of disturbance observe for position control. The difference between force and position disturbance observer is that the input and output of disturbance observer are forces in the case force disturbance observer and the plant varies much compared to the case of position control. In the design of force disturbance observer, generalized plant is derived and the stabilized filter is designed by H infinity control theory to ensure the robuts t stability even though the stiffness of environment changes from sponge to steel, and the contact surface also changes from flat to round shape. Experimental results show that highly robust force tracking by a 6-link electro-hydraulic manipulator could be achieved under various environment conditions.

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압전 작동기 및 감지기를 이용한 유연한 2링크 로봇팔의 위치 및 진동제어 (Position and Vibration Control of Flexible 2-Link Robot Arm Using Piezoelectric Actuators and Sensors)

  • 신호철;최승복;김승호
    • 한국정밀공학회지
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    • 제17권11호
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    • pp.206-212
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    • 2000
  • This paper presents a hybrid actuator scheme to actively control the end-point position and vibration of a two-link flexible robot arm. Control scheme consists of four different actuators; two servo-motors at the hubs and two piezoceramics bonded to the surfaces of the flexible links. Two sliding hyperplanes are designed for two servo-motors which have time varying parameters to maintain control performance in any configuration. The surface gradients of the hyperplanes are determined by pole assignment technique to guarantee the stability on the hyperplanes themselves. During the motion, undesirable oscillations caused by the torques based on the rigid link dynamics are actively suppressed by applying feedback control voltages to the piezoceramic actuators. Consequently, desired tip motion is achieved. In order to demonstrate the effectiveness of the proposed methodology, experiments are performed for the regulating and tracking control problems.

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클램핑 공정을 위한 유압실린더-부하계의 다축 위치 동기제어 (Multiple Axes Position Synchronizing Control of Hydraulic-Cylinder Load System for Clamping Process)

  • 조승호
    • 한국정밀공학회지
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    • 제31권1호
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    • pp.51-57
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    • 2014
  • This paper presents a synchronizing adaptive feedforward control for clamping servomechanism of injection molding machines. Based on MBS, virtual design model has been developed for a direct forcing clamping mechanism. A synchronizing controller is designed and combined with adaptive feedforward control to accommodate mismatches between the real plant and the linear plant model used. From tracking control simulations, it is shown that significant reduction in position tracking error is achieved through the use of proposed control scheme.

퍼지학습법을 이용한 크레인 시스템의 다변수 제어 (Control for Multi-variable in Crane System using Fuzzy Learning Method)

  • 임윤규;정병묵
    • 한국정밀공학회지
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    • 제16권7호
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    • pp.144-150
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    • 1999
  • n active control for the swing of crane systems is very important for increasing the productivity. This article introduces the control for the position and the swing of a crane using the fuzzy learning method. Because the crane is a multi-variable system, learning is done to control both position and swing of the crane. Also the fuzzy control rules are separately acquired with the loading and unloading situation of the crane for more accurate control. The result of simulations shows that the crane is just controlled for a very large swing angle of 1 radian within nearly one cycle.

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