• 한국정밀공학회지
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• 제21권11호
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• pp.130-139
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• 2004

The Casing Oscillator is a bore file Equipment for the all-casing process. All-casing process is a method of foundation work in construction yard to oscillate steel Casing in the ground. The existing Casing Oscillator has some problem like not boring horizontally with disturbance and not driving Casing othor angle except horizon. To solve problem, the new structure Casing Oscillator is presented and studied. The performance of Casing Oscillator is improved by kinematics analysis. The Casing Oscillator is similar to the parallel manipulator in structure. So we obtain Inverse kinematics solution of Casing Oscillator easily. But it is difficult to solve forward kinematics of Casing Oscillator. T his paper presents a novel pose description corresponding to the structure characteristics of parallel manipulators. Through analysis on geometry theory, we obtain a new method of the closed-form solution to the forward kinematics using Kinematic Inversion. The closed-form solution contains two different meanings -analytical and real-time. So we reach the goal of practical application and control. Closed-form forward kinematics solution is verified by an inverse kinematics analysis. It shows that the method has a practical value for real -time control and inverse kinematics servo control.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 A
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• pp.399-402
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• 1993

In this paper, an inverse kinematics of redundant manipulators is proposed. Optimality-constraint based inverse kinematic algorithms have some problems because those algorithms are based on necessary conditions for optimality. Among the problems, switching from a maximum value to a minimum value may occur and make an inverse kinematic solution unstable while performing a given task. An inverse kinematic solution for protecting from the switchings is suggested. By sufficient conditions for optimality, the configuration space is defined as a set of regions, potentially good configuration region and potentially bad configuration region. Inverse kinematics solution within potentially good configuration region can provide joint trajectories without both singularities and switchings. Through a simulation of tracing a circle, we show the effectiveness of this inverse kinematics.

• 한국생산제조학회지
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• 제7권1호
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• pp.104-111
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• 1998

This study solves the inverse kinematics problem of industrial FANUC robot. Because every joint angle of FANUC robot is dependent on the position of end-effector and the direction of approach vector, arm metrix T6 is very complicated and each joint angle is a function of other joint angles. Therefore, the inverse kinematics problem can not be solved by conventional methods. Noticing the fact that if one joint angle is known, the other joint angles are calculated by the algebraic methods. $ heta$1 is calculated using neumerical analysis method, and solves inverse kinematics problem. This proposed method, in this study, is more simpler and faster than conventional methods and is very useful in the real-time control of the manipulator.

• 한국정밀공학회지
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• 제29권10호
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• pp.1119-1127
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• 2012

In this paper, we present an inverse kinematics of a 7-dof Anthropomorphic robot arm using conformal geometric algebra. The inverse kinematics of a 7-dof Anthropomorphic robot arm using CGA can be computed in an easy way. The geometrically intuitive operations of CGA make it easy to compute the joint angles of a 7-dof Anthropomorphic robot arm which need to be set in order for the robot to reach its goal or the positions of a redundant robot arm's end-effector. In order to choose the best solution of the elbow position at an inverse kinematics, optimization techniques have been proposed to minimize an objective function while satisfying the euler-lagrange equation.

• 로봇학회논문지
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• 제6권1호
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• pp.27-33
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• 2011

Control and trajectory generation of a 7 DOF anthropomorphic robot arm suffer from computational complexity and singularity problem because of numerical inverse kinematics. To deal with such problems, analytical methods for a redundant robot arm have been researched to enhance the performance of inverse kinematics. In this research, we propose an analytical inverse kinematics algorithm for a 7 DOF anthropomorphic robot arm. Using this algorithm, it is possible to generate a trajectory passing through the singular points and intuitively move the elbow without regard to the end-effector pose. Performance of the proposed algorithm was verified by various simulations. It is shown that the trajectory planning using this algorithm provides correct results near the singular points and can utilize redundancy intuitively.

• 제어로봇시스템학회논문지
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• 제9권12호
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• pp.1026-1032
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• 2003

A biped walking robot which is developed as a platform for researching walking algorithm is briefly introduced. The developed walking robot has 6 degrees of freedom per one leg. The origins of the last three axis do not intersect at a point, so the kinematic analysis is cubmersome with the conventional method. In the former version of the robot, Jacobian-based inverse kinematics method is used. However, the Jacobian-based inverse kinematics method has drawbacks for the application in which knee is fully extended such as stair-case walking. The reason far that is the Jacobian becomes ill-conditioned near the singular points and the method is not able to give adequate solutions. So, a method for giving a closed-form inverse kinematics solution is proposed. The proposed method is based on careful consideration of the kinematic structure of the biped walking robot.

• 한국컴퓨터그래픽스학회논문지
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• 제5권1호
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• pp.11-17
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• 1999

Example guided inverse kinematics (EGIK)는 기존의 역운동학(inverse kinematics)을 확장, 향상시키는 알고리즘이다. 기존의 역운동학은 모델자체의 redundancy에 기인하여 jerky한 동작을 만들어내는 단점이 있다. EGIK에서는 미리 측정된 동작데이타를 효과적으로 이용하여 이러한 redundancy문제를 해결한다. 이 때 end-effector 위치 차이와 관절각의 차이를 동시에 최소화하기 위해서 비선형 최적화 기술이 사용된다. 우리는 결과로서의 동작이 원래의 동작의 특성을 잘 보존하는 자연스러운 것임을 보인다. EGIK는 기존의 동작 데이타를 이용하여 다관절체의 동작을 생성해내는 효과적인 기술이다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.655-658
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• 1999

In this paper we design a key-frame editor for 3D sign-language animation using the inverse kinematics. Using the editor, we can calculate the joint angles for two arms automatically. Up to now we have computed the values of the joint angles using the forward kinematics, where we have determined the values heuristically based on our experiences. To overcome the drawbacks, we employ the arm transformation matrix of the inverse kinematics. Experimental results show a possibility that the proposed method could be used for making up the sign-language communication dictionaries.

• 한국CDE학회논문집
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• 제14권5호
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• pp.291-296
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• 2009

This paper presents a post-processing algorithm for 5-axis machines with three rotary axes (3R-2L type). 5-axis machining needs the postprocessor for converting cutter location (CL) data to machine control (NC) data. The existing methods for post-processing use inverse kinematics equations from for-ward kinematics. However in case of 5-axis machines with three rotary axes, the inverse kinematics equations are not induced directly since the forward kinematics equations are non-linear. In order to get the joint values from the forward kinematics equations, previous algorithms use numerical method for the post-processing, which needs searching algorithms with computation time and may result in fail. This paper proposes a geometric method for the post-processing of 3 rotary type 5-axis machines. Our algorithm has three advantages: first, it does not need establishing forward kinematics equations. Second, it is reliable method that eliminates any numerical methods for the inverse kinematics, resulting in the exact solution. Finally, the proposed algorithm can also be applied to 2R-3L type of 5-axis machines.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제5권5호
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• pp.243-250
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• 2016

최근 가상현실(VR, virtual reality)이나 증강현실(AR, augmented reality)이 주목받으면서 이에 관한 컴퓨터 그래픽스(computer graphics)연구들이 활발히 진행되고 있다. 특히, 인간의 동작을 가상의 공간에서 구현하는 방법에 관한 연구들이 활발히 진행되고 있다. 하지만 많은 연구가 인간의 일반적인 동작에 한정되어 있다. 본 연구에서는 역운동학(IK, inverse kinematics)을 이용한 스포츠클라이밍 자세생성과 동작제어를 통해 인간의 일반적인 동작 이외에 스포츠클라이밍과 같은 특수 목적의 다양한 동작들을 삼차원의 가상공간에서 가상 인물(virtual character)의 자세 및 동작을 생성하는 시스템을 제안한다. 역운동학(IK, inverse kinematics) 기법을 통한 자세 생성은 역운동학 함수(IK function)와 실제 데이터를 통한 기본자세 애니메이션을 제작, 이를 활용하여 사실성을 더하고 자연스러운 자세 및 동작을 생성한다. 본 논문에서는 스포츠 클라이밍의 기본동작을 이용하여 올바른 자세와 함께 실제와 유사한 동작을 생성하는 시스템을 설계하였다. 이를 통해 클라이머를 위한 학습 프로그램이나 클라이밍 게임 같은 다양한 형태의 스포츠 클라이밍 콘텐츠를 제작하는데 도움이 되고자 한다.