• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.17 no.3
• /
• pp.7-15
• /
• 2018

Drilling processes require a cutting monitoring function that can be analyzed and gives feedback about strange conditions, tool collision and tool wear in real time. In this study, we proposed a drill monitor using the torque from the main spindle in CNC machine tools and a PROFIBUS network as a PLC-based interface. This paper studied drilling torque changes depending on drill size, the repetition cutting of the drilling and the drill's wear in the same cutting conditions. The material of the drills was high speed steel (HSS) and uncoated. The drills chosen were 2.7 mm, 6.7 mm, and 10.0 mm in diameter. These drills were selected because they had basic holes for their taps.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.12 no.3
• /
• pp.75-81
• /
• 2003

Pocket machining is metal removal operation commonly used for creating depressions in machined parts. Numerically controlled milling is the primary means for machining complex die surface. These complex surfaces are generated by a milling cutter which removes material as it traces out pre-specified tool paths. To machine, a component on a CNC machine, part programs which define the cutting tool path are needed. This tool path is usually planned from CAD, and converted to a CAM machine input format. In this paper I proposed a new method for generating NC tool paths. This method generates automatically NC tool paths with dynamic elimination of machining errors in 2$\frac{1}{2}$ arbitrary shaped pockets. This paper generates a spiral-like tool path by dynamic computing optimal pocket of the pocket boundary contour based on the type and size of the milling cutter, the geometry of the pocket contour and surface finish tolerance requirements. This part programming system is PC based and simultaneously generates a G-code file.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2008.11a
• /
• pp.205-209
• /
• 2008

In this study, very accurate computational mechatronics method has been developed for typical N.C. machine model applying to manufacturing industry in these days. Computation analysis of high speed machine tools like N.C. machine needs consideration about mechatronical features because the machine shows close interaction between dynamic behavior of the mechanical structure, drives and numerical control. For this, nonlinear structural analysis tools based on FEM are linked numerical control program to control the dynamic behavior. In this study, we studied the dynamic feature of N.C. machine by using SAMCEF as nonlinear computational structural analysis tool and simulink as drivers.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 1996.10a
• /
• pp.15-21
• /
• 1996

This paper describes a development of conversational program for lathe. The proposed program is a NC programming system specialized for use in machine tool controls. Its easy to use graphic interface built-in database capabilities make it an ideal way to program part on the shop floor. In order to manage effectively machining process it proposed the algorithm of tree structures for design processing. Also using interative structure it proposed the methods of conversational programming to generate automatically NC program.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.13 no.6
• /
• pp.56-63
• /
• 2004

The real-time NURBS interpolation method using 2-stage interpolation is studied. The 2-stage interpolation method that compensates for interpolation errors within machine BLU is proposed. The interpolation result was filtered by an Acceleration/Jerk limitation equation. Through this 2-stage interpolation, both the interpolation error condition and the motion kinematics could be satisfied. Using computer simulation in which interpolation results are evaluated by a numerical iteration method, it is shown that the 2-stage interpolation algerian could interpolate target curves precisely with geometric and dynamic contentment. The proposed algorithm was implemented in the CNC simulator system and an experimental un was conducted to identify the real-time adaptation.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.8 no.8
• /
• pp.1685-1691
• /
• 2004

The objective of this study is aimed at reducing the contour error of AC Servo derives by improving the interpolation error of each axis through variable structure control system. The errors in machining process by AC Servo motor are due to many elements, such as the delay of the servo drivers, friction and the gain mismatch between x axis and y axis motors and so on. Sliding mode control system is applied to a AC servo drive as a numerical example in this paper. The experiment results which are compared with those of typical PI scheme show the validity of improvement in circular interpolation error of the system.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.40 no.3
• /
• pp.327-336
• /
• 2016

Manufacturers of aircraft engines have introduced computer-aided manufacturing (CAM) software to operate and control computerized numerical control (CNC) machine tools. However, the generation of a CAM model is a time consuming and error-prone task since machining procedure and operational details are manually defined. For the automatic generation of a CAM model, feature recognition techniques have been widely studied. However, their recognition coverage is limited so that complex shapes such as a jet engine cannot be fully developed. This study presents a novel approach to quickly generate a CAM model from a CAD model using shape search techniques. Once an operator sets a machining operation as a reference operation, the same shapes as the shapes referenced by the operation are searched. The reference operation is copied to the positions of the searched shapes. The proposed method was verified through experiments with a jet engine compressor case.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.9 no.5
• /
• pp.590-597
• /
• 1985

A recursive geometric adaptive control method to compensate for machining straightness error in the finished surface due to tool deflection and guideway error generated by end milling process is developed. The relationship between the tool deflection and the feedrate is modeled by a modified Taylor's tool life equation. Without a priori knowledge on the variations off cutting parameters, time varying parameters are then estimated by an exponentially windowed recursive least squares method with only post-process measurements of the straightness error. The location error is controlled by shifting the milling bed in the direction perpendicular to the finished surface and adding a certain amount of feedrate with respect to the tool deflection model before cutting. The waviness error is compensated by adjusting the feedrate during machining. Experimental results show that location error is controlled within a range of fixturing error of the bed on the guideway and that about 60% reduction in the waviness error can be achieved within a few steps of parameter adaption under wide operating ranges of cutting conditions even if the parameters do not converge to fixed values.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.9
• /
• pp.1063-1070
• /
• 2011

The manufacturing execution system (MES) for product production handles different production processes according to the product characteristics and different types of data according to the process being considered. For efficiently providing the data pertaining to production equipment to production systems such as the MES, data collection through the equipment interface is required for obtaining the production data pertaining to field equipment. In this paper, a method is proposed for collecting the production data through the equipment interface in order to collect the various types of production-equipment data from the field. The proposed method is applied to a real manufacturing system to verify its efficiency. A more powerful MES can be constructed with a data acquisition system that acquires the status data at the shop-floor level.

• Journal of IKEEE
• /
• v.23 no.4
• /
• pp.1387-1392
• /
• 2019

Aspherical mirrors have lighter weight and better performance than spherical mirrors, but it is difficult to process their shape and measure the processing precision. Especially, large aperture aspherical mirrors mounted on satellites need high processing precision and long processing time. The computerized numerically controlled machine of gantry type has been used in polishing process, but it has difficulties in processing the complex shapes due to the lack of degrees of freedom. In order to overcome this problem we developed a polishing system using an articulated industrial robot. The system consists of tool path generating program, real-time robot monitoring, and control program. We show the performance of the developed system through the computer simulation and actual robot operation.