• 제목/요약/키워드: interpolator

검색결과 132건 처리시간 0.019초

고속 동작에 적합한 위상 내삽기 최적화 설계 기술 (Design Optimization Techniques of a Phase Interpolator for High-Speed Applications)

  • 황혜원;;전정훈;권기원
    • 대한전자공학회논문지SD
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    • 제49권1호
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    • pp.43-51
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    • 2012
  • 본 논문에서는 수학적 해석을 통해 위상 내삽기(Phase Interpolator, PI)를 최적화하는 설계 방법과 인덕터 부하를 이용하여 고속 동작에 적합하도록 개선한 저전력 PI 구조를 제안한다. 정해진 대역폭과 이득을 가지는 PI의 전력이 최소가 되는 설계 기준을 공정에 따라 정해지는 상수의 수식으로 제시한다. 또한, 제안된 인덕더 부하를 사용하는 PI구조는 같은 대역폭과 이득에서 소모 전력을 반으로 줄일 수 있다. $0.13{\mu}m$ 1.2V CMOS 공정에서 4개의 위상을 가지는 VCO 출력 신호를 이용하여 7-bit PI를 설계한 결과, 인덕터 부하를 사용하고 제안된 설계 기준에 따라 소모 전력을 최적화 하여 12GHz에서 $721.2{\mu}W$ 소모한다.

Edge Adaptive Hierarchical Interpolation for Lossless and Progressive Image Transmission

  • Biadgie, Yenewondim;Wee, Young-Chul;Choi, Jung-Ju
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제5권11호
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    • pp.2068-2086
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    • 2011
  • Based on the quincunx sub-sampling grid, the New Interleaved Hierarchical INTerpolation (NIHINT) method is recognized as a superior pyramid data structure for the lossless and progressive coding of natural images. In this paper, we propose a new image interpolation algorithm, Edge Adaptive Hierarchical INTerpolation (EAHINT), for a further reduction in the entropy of interpolation errors. We compute the local variance of the causal context to model the strength of a local edge around a target pixel and then apply three statistical decision rules to classify the local edge into a strong edge, a weak edge, or a medium edge. According to these local edge types, we apply an interpolation method to the target pixel using a one-directional interpolator for a strong edge, a multi-directional adaptive weighting interpolator for a medium edge, or a non-directional static weighting linear interpolator for a weak edge. Experimental results show that the proposed algorithm achieves a better compression bit rate than the NIHINT method for lossless image coding. It is shown that the compression bit rate is much better for images that are rich in directional edges and textures. Our algorithm also shows better rate-distortion performance and visual quality for progressive image transmission.

Simultaneous 3D Machining with Real-Time NURBS Interpolation

  • Hong, Won-Pyo;Lee, Seok-Woo;Park, Hon-Zong;Yang, Min-Yang
    • Journal of Mechanical Science and Technology
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    • 제17권3호
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    • pp.336-342
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    • 2003
  • Increasing demand on precision machining using computerized numerical control (CNC) machines have necessitated that the tool move not only with the smallest possible position error but also with smoothly varying feedrates in 3-dimensional (3D) space. This paper presents the simultaneous 3D machining process investigated using a retrofitted PC-NC milling machine. To achieve the simultaneous 3-axis motions, a new precision interpolation algorithm for 3D Non Uniform Rational B-Spline (NURBS) curve is proposed. With this accurate and efficient algorithm for the generation of complex 3D shapes, a real-time NURBS interpolator was developed using a PC and the simultaneous 3D machining was accomplished satisfactorily.

2축 윤곽제어를 위한 소프트웨어 보간자 개발에 관한 연구 (Development of Software Interpolator for Two-Axis Contouring Control)

  • 김교형;이기설
    • 대한기계학회논문집
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    • 제12권2호
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    • pp.389-396
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    • 1988
  • 본 연구에서는 위의 세가지 보간 알고리즘 가운데서 가장 속도의 균일성이 좋은 DDA방식을 채택하였다. 그리고 윤곽제어에서 가공경로는 대개 직선과 원호 구간의 조합으로 구성되어질 수 있기 때문에, 본 연구에서는 직선 및 원호보간만 고려하기로 한다.

CNC 공작기계의 NURBS 보간 알고리즘에 관한 연구 (NURBS Interpolation Algorithm for CNC Machines)

  • 홍원표;양민양
    • 한국정밀공학회지
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    • 제17권12호
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    • pp.115-120
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    • 2000
  • Increasing demands on precision machining of free-form surface have necessitated that the tool to move not only position error as small as possible, but also with smoothly varying feedrates. This paper presents new algorithm for high precision 3D(3-dimensional) NURBS(Non-Uniform Rational B-Spline) interpolation in the reference-pulse technique. Based o the minimum path error strategy, interpolation algorithm was designed to follow the NURBS curve. Using this algorithm a real-time 3D NURBS interpolator was developed in software. The algorithm implemented in a PC showed promising results in interpolation error and speed performance. It is expected that this can be applied to the CNC systems for the high precision machining of complex shapes.

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실시간 NURBS 보간에 의한 동시 3차원 가공에 관한 연구 (Simultaneous 3D Machining with Real-Time NURBS Interpolation)

  • 홍원표;양민양;이응기
    • 한국정밀공학회지
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    • 제19권5호
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    • pp.89-94
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    • 2002
  • Increasing demands on precision machining using CNC machines have necessitated that the tool to move with a position error as small as possible in 3-dimensional (3D) space. This paper presents the simultaneous 3D machining with a retrofitted PC-NC milling machine. To achieve the simultaneous 3-axis motions, a new precision interpolation algorithm for 3D Non-Uniform Rational B-Spline(NURBS) curve is used. With this accurate and efficient algorithm for the generation of complex. 3D shapes, a real-time NURBS interpolator was developed using a PC and the simultaneous 3D machining is accomplished.

고정밀 고속 윤곽가공을 위한 3축 연동제어기 (3-Axis Coupling Controller for High-Precision/High-Speed Contour Machining)

  • 지성철;구태훈
    • 대한기계학회논문집A
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    • 제28권1호
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    • pp.40-47
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    • 2004
  • This paper proposes a three-axis coupling controller designed to improve the contouring accuracy in machining of 3D nonlinear contours. The proposed coupling controller is based on an innovative 3D contour error model and a PID control law. The novel contour error model provides almost exact calculation of contour errors in real-time for arbitrary contours and can be integrated with any type of existing interpolator. In the proposed method, three axes of motion are coordinated by the proposed coupling controller along with a proportional controller for each axis. The proposed contour error model and coupling controller are evaluated through computer simulations. The simulation results show that the proposed 3-axis coupling controller with the new contour error model substantially can improve the contouring accuracy by order of magnitude compared with the existing uncoupled controllers in high-speed machining of nonlinear contours.

고속 고정밀의 자유곡선 가공을 위한 다축 윤곽오차 제어 (A Multi-Axis Contour Error Controller for High-Speed/High-Precision Machining of Free form Curves)

  • 이명훈;최정희;이영문;양승한
    • 한국정밀공학회지
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    • 제21권4호
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    • pp.64-71
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    • 2004
  • The growing need for higher precision and productivity in manufacturing industry has lead to an increased interest in computer numerical control (CNC) systems. It is well known fact that the cross-coupling controller (CCC) is an effective method for contouring applications. In this paper, a multi-axis contour error controller (CEC) based on a contour error vector using parametric curve interpolator is introduced. The contour error vector is a vector from the actual tool position to the nearest point on the desired path. The contour error vector is the closest error model to the contour error. The simulation results show that the CEC is more accurate than the conventional CCC for a biaxial motion system. In addition, the experimental results on 3-axis motion system show that the CEC is simply applied to 3-axis motions and contouring accuracy is significantly improved.