• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.869-874
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• 2004

The inverse kinematics of five-axis milling machines produce large errors near stationary points of the required surface. When the tool travels cross or around the point the rotation angles may jump considerably leading to unexpected deviations from the prescribed trajectories. We propose three new algorithms to repair the trajectories by adjusting the rotation angles in such a way that the kinematics error is minimized. Given the tool orientations and the inverse kinematics of the machine, we first eliminate the jumping angles exceeding ${\pi}$ by using the angle adjustment algorithm, leaving the jumps less than ${\pi}$ to be further optimized. Next, we propose to apply an angle switching algorithm to compute the rotations and identify an optimized sequence of rotations by the shortest path scheme. Further error reduction is accomplished by the angle insertion algorithm based an o special interpolation to obtain the required rotations near the singularity. We have verified the algorithms by five-axis milling machines, namely, MAHO600E at the CIM Lab of Asian Institute of Technology and HERMLE UWF902H at the CIM Lab of Kasetsart University.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.275-276
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• 2009

• Journal of Mechanical Science and Technology
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• v.17 no.4
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• pp.528-537
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• 2003

This paper proposes a 3-PPR planar parallel manipulator, which consists of three active prismatic Joints, three passive prismatic joints, and three passive rotational joints. The analysis of the kinematics and the optimal design of the manipulator are also discussed. The proposed manipulator has the advantages of the closed type of direct kinematics and a void-free workspace with a convex type of borderline. For the kinematic analysis of the proposed manipulator, the direct kinematics, the inverse kinematics, and the inverse Jacobian of the manipulator are derived. After the rotational limits and the workspaces of the manipulator are investigated, the workspace of the manipulator is simulated. In addition, for the optimal design of the manipulator, the performance indices of the manipulator are investigated, and then an optimal design procedure Is carried out using Min-Max theory. Finally. one example using the optimal design is presented.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.04b
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• pp.363-368
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• 1995

A general method of solving inverse kinematics of three-joint manipulator composed of revolute joints or prismatic joints or combinations of those joints is presented in this study. In completing real-time control, it is very important to obtain the closed form solutions of inverse kinematics rather than iterative numerical solutions, because iterative numerical solutions are generally much slower than the corresponding closed form solutions. If it is possible to obtain the inverse kinematic solutions for general cases of considering twist anlges and offsets, the manipulator work space can be designed and enlarged more effciently for specific task. Moreover, in idustrial manipulators, the effect of main three joints is larger than that of the other three joints related to orientation in the view of work space. Therfore the solutions of manin three-joint are considered. Even The inverse kinematic equations are complicatedly coupled, the systematical solving process by using symbolic calculation is presented.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.442-445
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• 2002

The casing oscillator used for the foundation work in the construction place. Construction machinery which makes the casing rotate and roll can insert the casing in the ground. It is very important to make the casing perpendicular to sea level regardless of slope of ground. So in this paper, we present the new type casing oscillator that need not to level the ground for the work of casing insertion. The inverse kinematics analysis for the real-time control of casing oscillator is presented.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.929-934
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• 2004

As 3D scanner develops, it can be used in measurement. To accomplish complete 3D measurement, the scanner has to view different sides of the target. It can be done by moving the scanner and fix it at every measuring point. By human, it would take so much time. However, by using robot, measuring time can be reduced and the procedure can be automated. It is suitable for 6R serial manipulator to do this kind of work in which the scanner should go any position in arbitrary orientation. We did inverse kinematics analysis by analytical and graphical methods. Then, we compared two methods.

• International Journal of Control, Automation, and Systems
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• v.4 no.1
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• pp.17-29
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• 2006

A novel inverse kinematics solution based on the back propagation neural network (NN) for redundant manipulators is developed for online obstacles avoidance. A laser transducer at the end-effctor is used for online planning the trajectory. Since the inverse kinematics in the present problem has infinite number of joint angle vectors, a fuzzy reasoning system is designed to generate an approximate value for that vector. This vector is fed into the NN as a hint input vector rather than as a training vector to guide the output of the NN. Simulations are implemented on both three- and four-link redundant planar manipulators to show the effectiveness of the proposed position control system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.661-665
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• 1996

An inverse kinemetics problem of a reclaimer which digs and transports ironstones or coals in the raw yard is investigated. Because of the special features of the reclaimer of which scooping buckets are attached around the rotating drum at the end of boom, kinematic redundancy occurs in determining the joint varialbes For a given reclaiming point in space the forward kinematics yields 3 equations, however the number of involved variables in the equations are four. A plane equation approximating the surface near a reclaiming point is obtained by considering 8 adjacent points surrounding the reclaiming point. One extra equation to overcome redunduncyis further obtained from the condition that the normal vector at a reclaiming point is perpendicular to the plane. An approximate solution for a simplified problem is first discussed, Numerical solution for the oritinal nonlinear porblem with a constraint equation is also investigated. Finally a closed form solution which is not exact but sufficiently close enough is proposed by exploiting geometric constraint.

• Journal of Mechanical Science and Technology
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• v.19 no.spc1
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• pp.320-327
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• 2005

A new mechanism for hyper redundant manipulator (HRM) is presented, which comprises of serially assembled compound three-bar linkages (CTL). The CTL mechanism has some unique properties. This paper presents the forward and inverse kinematics of this mechanism and shows the simulation of the HRM havig 9 CTL units. The recursive algorithm of the inverse kinematics that the author originally developed is employed. It is fast and stable ; moreover, it enables us to obtain a solution in which the end-point of the HRM is controlled by a portion of joints. It also presents the method of the dynamical analysis. There exist kinematical constraints in the proposed closed linkage mechanism. In the dynamic analysis constraints are sufficiently sustained by the constraint stabilization method that the author developed. The mechanical structure of the HRM having some CTL units that is under construction is shown.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.576-579
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• 2002

This paper presents the jacobian analysis of new type Casing Oscillator using the inverse kinematics, and to search for it's singularities through the jacobian analysis. All parallel manipulator have some singularities in workspace or it's outside workspace. Singularities were cleared by many other study of parallel manipulator f3r that reason recent publication of device control. In this paper defined that singularities of new file of Casing Oscillator and, to show it's graph. Finally this paper will be used for a practical example for construction spot, aviation simulator, vehicles simulator, military equipment etc.