• 대한기계학회논문집
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• 제18권8호
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• pp.2016-2025
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• 1994

A hierarchical planning strategy for dextrous manipulation of multifingered hands with soft finger contact model is proposed. Dextrous manipulation planning can be divided into a high-level stage which specifies the position/orientation trajectories of the fingertips on the object and a low-level stage which determines the contact forces and joint trajectories for the fingers. In the low-level stage, various nonlinear optimization problems are formulated according to the contact modes and integrated into a manipulation planning algorithm to find contact forces and joint velocities at each time step. Montana's contact equations are used for the high-level planning. Quasi-static simulation results are presented and illustrated by employing a three-fingered hand manipulating a sphere to demonstrate the validity of the proposed low-level planning strategy.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.505-510
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• 2002

The attenuation of waves transmitted through non-conservative joints that are shown in many paractical structures, is affected by the impedance and the orientation of the joint. In this paper, the joints between plate structures are assumed to be modeled as linear spring-dashpot systems and the transmission and reflection of vibration energy in the medium to high frequency ranges are investigated. The calculated power transmission and reflection coefficients are applied to the PFA method for the prediction of energy density and intensity in structures.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.353.2-353
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• 2002

The attenuation of waves transmitted through non-conservative joints that are shown in many practical structures, is affected by the impedance and the orientation of the joint. In this paper, the joints between plate structures are assumed to be modeled as linear spring-dashpot systems and the transmission and reflection of vibration energy in the medium to high frequency ranges are investigated. (omitted)

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.1173-1177
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• 1990

Cerebellar Model Linear Associator Net(CMLAN), a kind of neuro-net based adaptive control function generator, was applied to the problem of direct inverse calibration of three and six d.o.f. POMA 560 robot. Since CMLAN autonomously maps and generalizes a desired system function via learning on the sampled input/output pair nodes, CMLAN allows no knowledge in system modeling and other error sources. The CMLAN based direct inverse calibration avoids the complex procedure of identifying various system parameters such as geometric(kinematic) or nongeometric(dynamic) ones and generates the corresponding desired compensated joint commands directly to each joint for given target commands in the world coordinate. The generated net outputs automatically handles the effect of unknown system parameters and dynamic error sources. On-line sequential learning on the prespecified sampled nodes requires only the measurement of the corresponding tool tip locations for three d.o.f. manipulator but location and orientation for six d.o.f. manipulator. The proposed calibration procedure can be applied to any robot.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1986년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 17-18 Oct. 1986
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• pp.419-424
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• 1986

A technique is developed which allows a designer to interactively create an assembly of components by specifying mating contions between the individual components. Once establishing the relationships between components via the mating conditions, each component's location and orientation in the final assembly is computed. The joint information for a kinematic and dynamic analysis can be derived from the mating conditions, therefore this work may be extended to incorporate this analysis. Thorugh this development it will no longer be necessary for a designer to specify cumbersome and error prone transformation matrices in order to create an assembly. The designer also will be able to perform a kinematic or a dynamic analysis directly from an assembly model if the joint information can be automatically derived.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.60-65
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• 2003

A new algorithm was developed to interpret joint orientations from a pair of images of the rock slope to overcome the limitation of photographing direction as in the parallel stereophotogrammetric system and to maximize the range of image measurement. This algorithm can be regarded as a modified multistage convergent photographing system. To determine camera parameters in the perspective projection equation that are the major elements in the photogrammetric technique, a new concept was developed by using three ground control points and single ground guide point. This method could be considered to be very simple when compared with other existing methods which use a number of ground control points and complicated analysis processes.

• 한국정밀공학회지
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• 제6권3호
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• pp.32-45
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• 1989

The positioning accuracy of robots depends upon a forward kinematics which relates the joint variables to the orientation and position of the robot extremity in the absolute coordinate system. The relationship between two connective joint coordi- nates of a robot, which is the basis of the kinematics, is defined by 4 Denavit-Hartenberg parameters. But manufacturing errors in machining and assembly process of robots lead to disctrepancies between the design parameters and the physical structure. Thus, improving the positioning accuracy of robots reguires the identification of the actual link parameters of each robot. In this study, the least-squares method is used to calibrate the link parameters and off-line parameter calibration software is developed. Computer simulation is done to study the dependence of the calibration performance upon the DOF of the robot and number of acquired data set used in the least-squares method. 3 DOF Robot/Controller and specially designed 3D coordinate measurer is made and experiment is carried out to verify the theoretical and computational analysis.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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• pp.131-136
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• 1999

This paper proposes the robot inverse calibration method using a neural networks. A highorder networks called Pi-Sigma networks has been used. The Pi-Sigma networks uses linear summing units in the hidden layer and product unit in output layer. The inverse calibration model which compensates the difference of joint variables only between measuring value and analytic value about the desired pose(position, orientation) of a robot is proposed. The compensated values are determined by using the weights obtained from the learning process of the neural networks previously. To prove the reasonableness, the SCARA type direct drive robot(4-DOF) and anthropomorphic robot(6-DOF) are simulated. It shows that the proposed calibration method can reduce the errors of the joint variables from $\pm$2$^{\circ}$to $\pm$ 0.1$^{\circ}$.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 춘계학술대회 논문집
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• pp.199-204
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• 1999

The robot inverse calibration method using a neural networks is proposed in this paper. A high-order networks has been used in this study. The Pi-Sigma networks uses linear summing units in the hidden layer and product unit in output layer. The inverse calibration model which compensates the difference of joint variables only between measuring value and analytic value about the desired pose(position orientation) of a robot is proposed. The compensated values are determined by using the weights obtained from the learning process of the neural networks previously. To prove the reasonableness, the selected compliance automatic robot arm type direct drive robot and anthropomorphic robot are simulated. It shows that the proposed calibration method can reduce the errors of the joint variables from ${\pm}$0.15$^{\circ}$to ${\pm}$0.12$^{\circ}$.

• 자원환경지질
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• 제52권3호
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• pp.231-241
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• 2019

운동학적 분석은 암반사면 내에 존재하는 불연속면의 방향과 사면 방향 사이의 상관관계에 대한 분석을 통해 사면의 안정성을 파악하는 기법으로 본 연구에서는 지상라이다를 활용하여 암반사면으로부터 다수의 불연속면 자료를 획득하고 이를 활용하여 운동학적 분석을 수행하였다. 특히 본 연구에서는 지상라이다로부터 획득된 불연속면 방향성 자료의 확률특성을 파악하였으며 확률밀도함수인 Fisher 함수를 이용하여 방향자료를 생성하고 확률론적 분석을 수행하였다. 그리고 이러한 결과를 실제 현장으로부터 획득한 방향자료를 활용하여 분석을 수행한 확률론적 해석 결과와 비교해 보았다. 분석 결과 Fisher 함수로부터 생성된 자료를 활용한 확률론적 분석 결과와 현장자료를 활용한 확률론적 해석 결과는 값의 차이를 보이기는 하지만 유사한 결과를 도출하였다. 따라서 지상라이다 등과 같은 방법을 활용하여 충분한 방향성 자료가 제공되는 경우 확률밀도함수로부터의 방향자료 생성 없이 현장자료를 활용한 분석이 가능할 것으로 판단된다. 또한 본 연구에서는 확률론적 해석기법의 결과를 기존의 해석방식인 대표방향을 이용한 결정론적 해석기법과 비교해 보았다. 분석 결과 확률론적 해석 결과와 결정론적 해석 결과는 거의 유사하게 해석되었으며 이는 절리군내의 분산이 그리 크지 않아 확률론적 해석 결과와 결정론적 해석 결과가 유사한 것으로 판단된다.