• Journal of the Korean Society for Precision Engineering
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• v.21 no.11
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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.

• Proceedings of the KIEE Conference
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• 1993.07a
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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.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.1
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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.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.10
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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.

• The Journal of Korea Robotics Society
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• v.6 no.1
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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.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.12
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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.

• Journal of the Korea Computer Graphics Society
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• v.5 no.1
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• pp.11-17
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• 1999

This paper proposes example guided inverse kinematics (EGIK) which extends and enhances existing inverse kinematics technique. In conventional inverse kinematics, redundancy in the model produces an infinite number of solutions. The motion could be jerky depending on the choice of solutions at each frame. EGIK exploits the redundancy for imitating an example motion (a premeasured motion data) so that a unique solution is chosen. To minimize the gap between the goal and current end-effector position and imitate the original motion at the same time, nonlinear optimization technique is employed. So, the resulting motion resembles the original one in an optimal sense. Experiments prove that the method is a robust and effective technique to animate high DOF articulated models from an example motion.

• Proceedings of the IEEK Conference
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• 1999.06a
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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.

• Korean Journal of Computational Design and Engineering
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• v.14 no.5
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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.

• KIPS Transactions on Software and Data Engineering
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• v.5 no.5
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• pp.243-250
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• 2016

Recently, public interest in virtual reality (VR) and augmented reality (AR) has increased. Therefore, computer graphics-related research has been actively conducted. This has included research on virtual space related to human posture implementation. However, such research has focused on general posture in humans. This paper presents a system with reference to the basic posture in sports climbing and the inverse kinematics method for generating the positions and behavior of virtual characteristics in a three-dimensional virtual space. The simulation based on the inverse kinematics method, produced with an inverse kinematics solver and initial pose animation from motion capture, provides realistic and natural movement. We designed a simulation system to generate correct posture and motions similar to those in sports climbing by applying the basic procedure of sports climbing. The simulation system provides help for producing content about sports climbing, such as learning programs for novice climbers and sports climbing games.