• The Journal of Korea Robotics Society
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• v.10 no.4
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• pp.230-244
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• 2015

Continuous-path motion control such as resolved motion rate control requires online solving of the inverse differential kinematics for a robot. However, the solution space of the inverse differential kinematics related to Jacobian J is not well-established. In this paper, the solution space of inverse differential kinematics is analyzed through categorization of mapping conditions between joint velocities and end-effector velocity of a robot. If end-effector velocity is within the column space of J, the solution or the minimum norm solution is obtained. If it is not within the column space of J, an approximate solution by least-squares is obtained. Moreover, this paper introduces an improved mapping diagram showing orthogonality and mapping clearly between subspaces, and concrete examples numerically showing the concept of several subspaces. Finally, a solver and graphics user interface (GUI) for inverse differential kinematics are developed using MATLAB, and the solution of inverse differential kinematics using the GUI is demonstrated for a vertically articulated robot.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.29 no.4
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• pp.279-285
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• 1993

Robot inverse kinematics solution is a complex nonlinear equation and very time-consuming task. This paper propose to use TSK fuzzy reasoning for solving robot inverse kinematics. A fuzzy model of inverse kinematics is identified by using input-output data and the model is used to solve the inverse kinematics. To show that, when used in robot inverse kinematics, fuzzy model is simple and generates a fairly accurate solution, a fuzzy model of inverse kinematics for PUMA robot is constructed.

• 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.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1996.10a
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• pp.166-171
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• 1996

Generally, when we control the robot, we should calculate exactly Inverse Kinematics. However, Inverse Kinematics calculation is complex and it takes much time for the manipulator to control in real-time. Therefore, the calculation of Inverse Kinematics can result in significant control delay in real time. In this paper, we will present that Inverse Kinematics can be calculated through Fuzzy Logic Mapping, Based on an exact solution through fuzzy reasoning instead of Inverse Kinematics calculation Also, the result provides sufficient precision and transient tracking error can be controlled based on a fuzzy adaptive scheme proposed in this paper. Based on the Denavit-Hartenberg parameters specification, after the Jacobian matrix of arbitrary manipulator is calculated, we will construct Fuzzy Inverse Kinematics Mapping(FIKM) using fuzzy logic and represent a good control efficiency through simulation of 2-DOF manipulator.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.551-556
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• 1991

This paper deal with the solution of kinematics and inverse kinematics of industrial FANUC robot by the bisection method with IBM PC 386. The inverse kinematics of FANUC robot cannot be solved by the algebraical method, because arm matrix T$_{6}$ is very complex and 6-joint angles are associated with the position and the approach of end-effector. Instead we found other 5-joint angle by an algebraical method after finding .theta.$_{4}$ value by a bisection method.d.

• 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.

• Proceedings of the KIEE Conference
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• 2003.11b
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• pp.239-242
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• 2003

In this paper, we propose how to determine the optimal camera position using inverse kinematics of virtual link model and manipulability measure. We model the variable distance and viewing direction between a target object and a camera position as a virtual link. And, by using inverse kinematics of virtual link model, we find out regions that satisfy the direction and distance constraints for the observation of target object. The solution of inverse kinematics of virtual link model simultaneously satisfies camera accessibility as well as a direction and distance constraints. And we use a manipulability measure of active camera system in order to determine an optimal camera position among the multiple solutions of inverse kinematics. By using the inverse kinematics of virtual link model and manipulability measure, the optimal camera position in order to observe a target object can be determined easily and rapidly.

• Korean Journal of Computational Design and Engineering
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• v.13 no.2
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• pp.153-161
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• 2008

This paper proposes an efficient algorithm for deriving inverse kinematics equation of 5-axis machine. Because the joint order and direction of 5-axis machine are different for each type of machine, each type of machine needs its own inverse kinematics equation for post-processing of NC data. Also derived inverse kinematics equation may cause problems of indeterminate and inconsistent solution. In order to resolve these problems, we have developed a generic method to derive direct kinematics equation by considering orthogonal joints of 5-axis machines. Using this method, we also have proposed a general algorithm for deriving inverse kinematics equation for various types of 5-axis machines.

• Proceedings of the IEEK Conference
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• summer
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• pp.263-268
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• 2004

The inverse kinematics problem is to find a set of joint variable values that will place the end effector of a robot manipulator into a given pose. Pieper has shown that a sufficient condition for a manipulator to have a closed form solution is that three adjacent joint axes intersects, hence the six axes robot with spherical wrist allows closed form solution. But many industrial robots have a non-spherical wrist to provide a stronger wrist configuration so that they can handle heavy payloads. Also, the use of a non-spherical wrist can result in a cheap and simple wrist arrangement than when all three axes intersect at a common point. In these cases, closed form solutions cannot be found. Therefore numerical technique must be used to solve the inverse kinematics equations. This paper proposes a new algorithm that can be used for finding inverse kinematics solution of the six axes robot with non-spherical wrist. Computer simulations are provided to prove the usefulness of our method.