• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.6
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• pp.783-790
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• 2013

Circular path generation for ball bar measurement using the simultaneous movement of two axes with at least one rotary axis requires the execution of CAM software. However, a change in the machine type or measurement condition requires a new execution of the CAM software, which is cumbersome. This paper presents a circular path generation technique that does not require CAM software and is applicable to different types of driving axes with an arbitrary structural configuration of machine tools and any ball bar setup condition. Mathematical equations are derived for three cases using the proposed technique. In addition, to inspect the measurement feasibility for avoiding physical interference among the ball bar parts, a tilting angle calculation is proposed. The validity of the proposed technique was verified by performing a ball bar experiment with A and C as the simultaneous axes of a five-axis machine tool.

• Korean journal of applied entomology
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• v.55 no.2
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• pp.177-188
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• 2016

The alpha-proteobacterium Wolbachia is one of the most important intracellular symbionts of arthropods. This Gram-negative bacterium is involved in many biological processes and is currently considered as a potential tool for biological control. Wolbachia is a cytoplasmic bacterium, maternally transferred through generations, and to facilitate its success, it has evolved several strategies that manipulate its host reproductive system to increase the number of infected individuals in the host population. The variety of Wolbachia was first recognized using genes wsp, 16S rRNA, ftsZ, gltA and groEL as molecular markers while strain genotypes of Wolbachia are determined of Multilocus sequence typing (MLST) and sequence of amino acid in region, hyper variable regions (HVRs) in protein WSP. Possible uses of the bacteria and their predominant phenotypes in control programs for agricultural pests and human disease vectors have been considered. Phenotypes are known to induce cytoplasmic incompatibility (CI), parthenogenesis induction (PI), feminization (F) and male killing (MK). Finally, applications of the bacterium in control programs of agricultural and medical insect pests have been discussed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.1
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• pp.97-103
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• 2013

This study proposes a path generation technique for simultaneous five-axis driving for ball bar measurement, which is equivalent to cone frustum machining as mentioned in the NAS979 standard. The technique is generalized for a 3D circular path, and it is applicable to all machine tools regardless of their structural configurations. A mathematical machine input model that consists of a five-axis machine tool, ball-bar measurement and conical path information as inputs is presented for easy NC code generation, simulation for various test conditions, and a measurement test. The movement range of rotary axes, which depends on various conditions, is mathematically analyzed based on the proposed conical path model. Moreover, the effect of the movement range on various conditions (apex angle and inclination angle, ball bar tilting acceptance angle, offset position of workpiece ball, etc.) is analyzed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.336-342
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• 1994

This paper presents an useful technique for assessing the volumetric error in multi_axis machine tools using the kinematic double ball bar and 3 dimensional spherical contouring. The developed system proposes the 3 dimensional spherical contour for the error analysis. The developed system input the measured radial data, analysing the volumetric errors such as positional, strightness, angle, and squareness errors, etc. The developed system has been tested in a practical machine tool, and showed high

• Feed Journal
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• v.5 no.5 s.45
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• pp.65-68
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• 2007

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.9
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• pp.1359-1367
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• 2001

Improvement of machine tool accuracy is an essential part of quality control in manufacturing process. Among of all the errors of a particular machine tool, the thermal errors of the spindle have a notably significant effect on machining accuracy and have a direct influence upon both the surface finish and geometric shape of the finished workpiece. Therefore, this paper proposed new measurement method for thermal errors of the spindle in machine tools. The thermal errors are measured by a ball bar system instead of capacitance sensor system. The novel measurement method using ball bar system is more efficient, easier to use than conventional measurement system. And also the ball bar system is possible to measure both geometric errors and thermal errors at the same time.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.501-504
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• 2001

The use of error compensation techniques has been recognized as an effective way in the improvement of the accuracy of a machine tool. The laser measurement method for identifying position errors of machine tool has the disadvantages such as high cost, long calibration time and usage of volumetric error synthesis model. Accordingly, this paper deals with analysis of the position errors of a machine tool using ball bar test without using complicated error synthesis model. Statistical analysis method was adopted in this paper for deriving position errors using hemispherical helix ball bar test.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.2
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• pp.56-63
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• 2001

The objective of this research is to develop a measurement error compensation method for On-Machine Measurement (OMM) process based on a closed-loop configuration. Geometric errors of vertical machining center are measured using ball-bar system, and probing errors are measured using master ball. The errors are represented using homogeneous trans-formation matrices and the closed-loop configuration method is applied to calculate 3-dimensional errors. To verify the effectiveness of the method proposed in this research, compensated results are compared to the data using CMM process, and the results are analyzed. The results show the proposed method can be applied in OMM process to make the measured data more reliable.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.703-707
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• 2000

Machine tool errors have to be characterized and predicted to improve machine tool accuracy. A real-time error compensation system has been developed based on volumetric error synthesis model which is composed of machine tool errors. This paper deals with new algorithm about verification of machine tool errors. This new algorithm uses a simplified volumetric error synthesis model. This simplified model is constructed with only main components among the error components of the machines. This main error components are analyzed by three-dimensional helical ball bar test. By substituting result of helical ball bar test fer simplified model, we could find that obtained error components are closed to real error components.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.6
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• pp.114-121
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• 1996

This paper presents an useful technique for assessing the volumetric errors in multi-axis machine tools using the kinematic double ball bar. This system has been developed based on the volumetric error map which describes the 3 dimensional errors of machine tools. The developed system inputs the measured radial data of 3 different planes, respectively XY,YZ,ZX, analysing the volumetric errors such as positional. straightness, angle, and squareness errors, etc. The developed system has been tested in a practical machine tool, and showed high potential for the error assessment of multi-axis machine tools.