• Title/Summary/Keyword: Constraint Operator

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Constraint Operator for the Kinematic Calibration of a Parallel Mechanism

  • Lee, Min-Ki;Kim, Tae-Sung;Park, Kun-Woo;Kwon, Sung-Ha
    • Journal of Mechanical Science and Technology
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    • v.17 no.1
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    • pp.23-31
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    • 2003
  • This paper introduces a constraint operator for the kinematic calibration of a parallel mechanism. By adopting the concept of a constraint operator, the movement between two poses is constrained. When the constrained movements are satisfied, the active joint displacements are taken and inputted into the kinematic model to compute the theoretical movements. A cost function is derived by the errors between the theoretical movement and the actual movement. The parameters that minimize the cost function are estimated and substituted into the kinematic model for a kinematic calibration. A single constraint plane is employed as a mechanical fixture to constrain the movement, and three digital indicators are used as the sensing devices to determine whether the constrained movement is satisfied. This calibration system represents an effective, low cost and feasible technique for a parallel mechanism. A calibration algorithm is developed with a constraint operator and implemented on a parallel manipulator constructed for a machining center tool.

Study on the Observability of Calibration System with a Constraint Oprerator (구속연산자에 의한 보정 시스템의 관측성에 관한 연구)

  • Lee, Min-Ki;Kim, Tae-Sung;Park, Kun-Woo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.4
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    • pp.647-655
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    • 2003
  • This paper studies the observability of calibration system with a constraint movement by a constraint operator. The calibration system with the constraint movement need only simple sensing device to check whether the constraint movements are completed within an established range. However, it yields the concern about the poor parameter observability due to the constraint movements. This paper uses the QR-decomposition to find the optimal calibration configurations maximizing the linear independence of rows of a observation matrix. The number of identifiable parameters are examined by the rank of the observation matrix, which represents the parameter observability. The method is applied to a parallel typed machining center and the calibration results are presented. These results verify that the calibration system with low-cost indicators and simple planar table is accurate as well as reliable.

Analysis on a Power Transaction with Fuel-Constrained Generations in an Electricity Market (연료제약 발전기를 고려한 전력거래 해석기법 연구)

  • 이광호
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.53 no.8
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    • pp.484-489
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    • 2004
  • When the energy resource available to a particular plant (be it coal, oil, gas, water, or nuclear fuel) is a limiting factor in the operation of the plant, the entire economic dispatch calculation must be done differently. Each economic dispatch calculation must account for what happened before and what will happen in the future. This paper presents a formulation and a solution method for the optimization problem with a fuel constraint in a competitive electricity market. Take-or- Pay (TOP) contract for an energy resource is the typical constraint as a limiting factor. Two approaches are proposed in this paper for modeling the dispatch calculation in a market mechanism. The approaches differ in the subject who considers and inserts the fuel-constraint into its optimization problem. Market operator and each power producer having a TOP contract are assumed as such subjects. The two approaches are compared from the viewpoint of profits. surplus. and social welfare on the basis of Nash Equilibrium.

A PSEUDOCONVEX PROGRAMMINA IN A HILBERT SPACE

  • Yoon, Byung-Ho;Kim, In-Soo
    • Bulletin of the Korean Mathematical Society
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    • v.23 no.2
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    • pp.141-148
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    • 1986
  • In [1], M. Guignard considered a constraint set in a Banach space, which is similar to that in [2] and gave a first order necessary optimality condition which generalized the Kuhn-Tucker conditions [3]. Sufficiency is proved for objective functions which is either pseudoconcave [5] or quasi-concave [6] where the constraint sets are taken pseudoconvex. In this note, we consider a psedoconvex programming problem in a Hilbert space. Constraint set in a Hillbert space being pseudoconvex and the objective function is restrained by an operator equation. Then we use the methods similar to that in [1] and [6] to obtain a necessary and sufficient optimality condition.

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A Study on the LQG/LTR for Nonminimum phase plant : Optimal Approximation method (비 최소위상 시스팀에 대한 LQG/LTR 연구 - 최적 근사화 방법)

  • 서병설;강진식;이준영
    • 제어로봇시스템학회:학술대회논문집
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    • 1991.10a
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    • pp.191-196
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    • 1991
  • LQG/LTR method have a theoretical constraint that it cannot applied to nonminimum phase plant. In this paper, we suggest two methods of approximation of minimum phase plant for a given nonminimum phase plant to solve this constraint. Error is described by additive form which can reduce its magnitude in broad frequency range. A optimal approximation method was suggesetd by using Hankel operator theory and Nehari theory. It is showen by example that the methods suggested can resolve the frequency domain constraint arised in Stein and Athans approximation.

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A Study on the LQG/LTR for Nonminimum Phase Plant (I) : Optimal Approximation Method (비 최소위상 플랜트에 대한 LQG/LTR에 관한 연구(I) : 최적 근사 방법)

  • 강진식;서병설
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.16 no.10
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    • pp.972-980
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    • 1991
  • LQG/LTR method have a theoretical constraint that it cannot applied to nonminimum phase plant. In this paper we suggest two methods of approximation of minimum phase plant for a given nonminimum phase plant to solve this constraint. Error is described by additive form which can reduce its magnitude in broad frequency range. A optimal approximation method was suggested by using Hankel operator theory and Nehan theory it is shown by example that the methods suggested can resolve the frequency domain constraint arised in Stein and Athans approximation.

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Analysis on a Generation Competition with Take-Or-Pay Contract in an Electricy Market (연료제약 발전기의 강제인수 조건이 반영된 전력거래 해석)

  • Lee Kwang Ho;Cho Cheol Hee;Shin Jae Hong
    • Proceedings of the KIEE Conference
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    • summer
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    • pp.716-718
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    • 2004
  • This paper presents a formulation and a solution method for the optimization problem with a fuel constraint in a competitive electricity market. Take-or-Pay (TOP) contract for an energy resource is the typical constraint as a limiting factor. Two approaches are proposed in this paper for modeling the dispatch calculation in a market mechanism. The approaches differ in the subject who considers and inserts the fuel-constraint into its optimization problem. Market operator and each power producer having a TOP contract are assumed as such subjects.

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Study on Kinematic Calibration of a Parallel-typed Machining Center Tool (병렬기구형 공작기졔의 기구학적 보정에 관한 연구)

  • Lee, Min-Ki;Kim, Tae-Sung;Park, Kun-Woo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.11
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    • pp.2237-2244
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    • 2002
  • This research develops a low-cost and high accuracy kinematic calibration method based on the following principles: 1) the platform locations are accurately measured by a constrained movement to inspect a calibration target; 2) the constrained movement is chosen to guarantee the parameter observability; 3) the mechanical fixture to constrain the movement and the sensor to check the constrained movement are implemented by low-cost and high-accuracy devices; 4) the calibration is easily done at an industrial environment. The kinematic parameters calibrated with respect to a single plane aren't influenced due to the misalignment of the plane. A parameter observability is successfully obtained even through one planar constraint, which guarantees that all kinematic parameters are estimated by minimizing the cost function.

Development of Kinematic Calibration System for a Parallel-typed Machining Center Tool (병렬기구형 공작기계의 보정 시스템 개발)

  • Kim, Tae-Sung;Park, Kun-Woo;Yoon, Tae-Sung;Lee, Min-Ki
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.521-526
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    • 2001
  • This research develops a low-cost and high accurate kinematic calibration method for a parallel typed machining center tool. A planar table is used for a mechanical fixture restricting the platform to place at the constrained pose and a low-cost and high accurate digital indicator is employed for a device checking if the constrained movement is satisfied within the established range. The kinematic parameters calibrated with respect to a single plane aren't influenced from the misalignment of the plane. A parameter observability is successfully obtained even through one planar constraint, which guarantees that the kinematic parameters is estimated by minimizing the cost function.

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