• 제목/요약/키워드: deflection control

검색결과 410건 처리시간 0.021초

일정한 가반 하중이 작용하는 스카라 로봇에 대한 신경망을 이용한 기계적 처짐 오차 보상 제어 (Compensation Control of Mechanical Deflection Error on SCARA Robot with Constant Pay Load Using Neural Network)

  • 이종신
    • 제어로봇시스템학회논문지
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    • 제15권7호
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    • pp.728-733
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    • 2009
  • This paper presents the compensation of mechanical deflection error in SCARA robot. End of robot gripper is deflected by weight of arm and pay-load. If end of robot gripper is deflected constantly regardless of robot configuration, it is not necessary to consider above mechanical deflection error. However, deflection in end of gripper varies because that moment of each axis varies when robot moves, it affects the relative accuracy. I propose the compensation method of deflection error using neural network. FEM analysis to obtain the deflection of gripper end was carried out on various joint angle, the results is used in neural network teaming. The result by simulation showed that maximum relative accuracy reduced maximum 9.48% on a given working area.

A Compensation Control Method Using Neural Network for Mechanical Deflection Error in SCARA Robot with Random Payload

  • Lee, Jong Shin
    • 한국기계기술학회지
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    • 제13권3호
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    • pp.7-16
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    • 2011
  • This study proposes the compensation method for the mechanical deflection error of a SCARA robot. While most studies on the related subject have dealt with the development of a control algorithm for improvement of robot accuracy, this study presents the control method reflecting the mechanical deflection error which is predicted in advance. The deflection at the end of the gripper of SCARA robot is caused by the self-weights and payloads of Arm 1, Arm 2 and quill. If the deflection is constant even though robot's posture and payload vary, there may not be a big problem on robot accuracy because repetitive accuracy, that is relative accuracy, is more important than absolute accuracy in robot. The deflection in the end of the gripper varies as robot's posture and payload change. That's why the moments $M_x$, $M_y$ and $M_z$ working on every joint of a robot vary with robot's posture and payload size. This study suggests the compensation method which predicts the deflection in advance with the variations in robot's posture and payload using neural network. To do this, I chose the posture of robot and the payloads at random, found the deflections by the FEM analysis, and then on the basis of this data, made compensation possible by predicting deflections in advance successively with the variations in robot's posture and payload through neural network learning.

직접형상제어를 위한 공구경로의 보상 : 2D 윤곽가공의 공구휨을 중심으로 (Path compensation toward direct shape control: dealing with tool deflection problem in 2D contour machining)

  • 조정훈;서석환
    • 한국정밀공학회지
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    • 제12권2호
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    • pp.97-111
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    • 1995
  • In this paper, we investigate path compensation scheme for the machining errors due to tool deflection in 2D contour machining. The significance of the deflection error is first shown by experiments, and a direct compensation scheme is sought. In the presented scheme, the tool path is evaluated and correcte based on the instantaneous deflection force model, until the desired contour can be obtained under the presence of tool deflection in actual machining. In the sense that the developed method estimates and compensates the machining errors via modifying the tool path, it is distinguished from the previous approach based on geometric simulation and cutting simulation. Further, it can be viewed as a direct and active method toward direct shape control in CNC machining. Simulation results are included to show the validity and adequacy of the path-modification scheme under various cutting conditions.

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Review of design parameters for FRP-RC members detailed according to ACI 440.1R-06

  • Jnaid, Fares;Aboutaha, Riyad
    • Computers and Concrete
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    • 제11권2호
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    • pp.105-121
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    • 2013
  • This paper investigates the parameters that control the design of Fiber Reinforced Polymer (FRP) reinforced concrete flexural members proportioned following the ACI 440.1R-06. It investigates the critical parameters that control the flexural design, such as the deflection limits, crack limits, flexural capacity, concrete compressive strength, beam span and cross section, and bar diameter, at various Mean-Ambient Temperatures (MAT). The results of this research suggest that the deflection and cracking requirements are the two most controlling limits for FRP reinforced concrete flexural members.

에일러론 링키지 해석을 통한 작동기 변위와 조종면 변위의 상관관계 규명 (Investigation of Kinematic Relation Between Actuator and Control Surface Deflection Using Aileron Linkage Analysis)

  • 이석천;이상종
    • 항공우주시스템공학회지
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    • 제6권3호
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    • pp.24-28
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    • 2012
  • An actuator should be added to a existing control linkage to make manned aircraft to unmanned. But it is quiet difficult to synchronize actuator with control surface because non-linear error necessarily occurs when four-bar linkage acts in three dimensional motion. In addition, in point of controller design view, while a real-time model needs the control surface deflection as its input, controller needs the actuator command as its output. Hence, the relation between both should be investigated. In this paper, the mathematical relation between actuator and control surface deflection investigated by kinematic analysis of a plant aircraft. The performance margin of the selected actuator also was verified.

전위차계를 이용한 무인항공기 조종면 변위 측정 장치 구현 및 적용 (Implementation and Application of the Control Surface Deflection Angle measuring device for UAV using Potentiometer)

  • 김지철;최일규;공성철;전동익;이상철;오화석;강민영
    • 항공우주시스템공학회지
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    • 제3권3호
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    • pp.13-16
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    • 2009
  • Aircraft flight control surfaces which are one of the most important elements of safety allow a pilot to adjust and control the aircraft's flight attitude. This paper is described of the control surface deflection angle measuring device. Data analysis through ground test and flight test can provide reliability of this device using the present system. It is also shown that measuring system is capable of detecting failure of control surfaces.

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철근콘크리트 휨부재의 처짐 간접제어를 위한 한계 지간/깊이-비 연구 (Limit Span/Depth Ratio for Indirect Deflection Control in Reinforced Concrete Flexural Members)

  • 최승원;김우
    • 대한토목학회논문집
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    • 제31권1A호
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    • pp.35-41
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    • 2011
  • 콘크리트구조설계기준에서는 일반적으로 처짐을 제어하기 위해 직접처짐제어법과 간접처짐제어법을 제시하고 있다. 이 때 처짐/깊이-비는 허용 처짐량을 초과하지 않도록 제한된다는 점에서 간접처짐제어법이 더 효과적이다. 실제 처짐량은 많은 요소에 의해 영향을 받기 때문에 실제 처짐량을 정확하게 산정하는 것은 어렵다. 이 연구에서는 철근콘크리트 부재의 사용한 계상태에서 처짐량을 직접 계산함으로써 한계 지간/깊이-비를 산정하였다. 이 때 처짐은 재료 모델로부터 산정된 휨곡률을 통해 산정하였다. 해석의 주요 변수는 인장증강효과 모델, 콘크리트 강도, 단면 크기 및 압축 철근의 유무이다. 해석 결과 2차식 형태의 인장증강효과 모델을 사용함으로써 해석의 일관성을 도모할 수 있는 것으로 나타났다. 또한 한계 지간/깊이-비는 단면 크기와 관계없이 재료 강도와 인장 및 압축 철근비에 따라 변화하는 것으로 나타났다.

Dynamic Responses and Fuzzy Control of a Simply Supported Beam Subjected to a Moving Mass

  • Kong, Yong-Sik;Ryu, Bong-Jo;Shin, Kwang-Bok;Lee, Gyu-Seop;Lee, Hong-Gi
    • Journal of Mechanical Science and Technology
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    • 제20권9호
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    • pp.1371-1381
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    • 2006
  • This paper deals with the active vibration control of a simply-supported beam traversed by a moving mass using fuzzy control. Governing equations for dynamic responses of a beam under a moving mass are derived by Galerkin's mode summation method, and the effect of forces (gravity force, Coliolis force, inertia force caused by the slope of the beam, transverse inertia force of the beam) due to the moving mass on the dynamic response of a beam is discussed. For the active control of dynamic deflection and vibration of a beam under the moving mass, the controller based on fuzzy logic is used and the experiments are conducted by VCM (voice coil motor) actuator to suppress the vibration of a beam. Through the numerical and experimental studies, the following conclusions were obtained. With increasing mass ratio y at a fixed velocity of the moving mass under the critical velocity, the position of moving mass at the maximum dynamic deflection moves to the right end of the beam. With increasing velocity of the moving mass at a fixed mass ratio ${\gamma}$, the position of moving mass at the maximum dynamic deflection moves to the right end of the beam too. The numerical predictions of dynamic deflection of the beam have a good agreement with the experimental results. With the fuzzy control, more than 50% reductions of dynamic deflection and residual vibration of the tested beam under the moving mass are obtained.

병렬퍼지 제어기와 기준궤적신호를 이용한 유연한 매니퓰레이터의 진동제어 (The vibration control of Flexible Manipulator using Parallel Fuzzy controller and Reference Trajectory Command)

  • 박양수;박윤명
    • 융합신호처리학회논문지
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    • 제3권1호
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    • pp.61-66
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    • 2002
  • A fuzzy control strategy is described which is utilized to control the joint angle and tip deflection in single flexible manipulator. In this paper, an existing model for a single flexible manipulator is used for the initial development of an FLC. One FLC is designed to govern the joint angle of the manipulator as it is rotated from one position to another, and the second FLC is designed to attenuate the tip deflection which result from joint angle body motion. Reference Trajectory Command is an important method to reduce vibration in flexible beam. This paper presents a very simple command control shaping which eliminates multiple mode residual vibration in a flexible beam combined parallel fuzzy controller. The effectiveness of proposed scheme is demonstrated through computer simulation.

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초기변형 최소화를 위한 광변조 압전 다층박막 액추에이터의 설계, 제작 및 실험 (Design Fabrication and Test of Piezoelectric Multi-Layer Cantilever Microactuators for Optical Signal Modulation)

  • 김명진;조영호
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제49권9호
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    • pp.495-501
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    • 2000
  • This paper presents a method to minimize the initial deflection of a multi-layer piezoelectric microactuator without loosing its piezoelectric deflection performance required for light modulating micromirror devices. The multi-layer piezoelectric actuator composed of PZT silicon nitride and platinum layers deflects or buckles due to the gradient of residual stress. Based on the structural analysis results and relationship between process conditions and mechanical properties we have modified the fabrication process and the thickness of thin film layers to reduce the initial residual stress deflection without decreasing its piezoelectric deflection performance. The modified designs fabricated by surface-micromachining process achieved the 77% reduction of the initial deflection compared with that of the conventional method based on the measured micromechanical material properties is applicable to the design refinement of multi-layer MEMS devices and micromechanical structures.

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