• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.748-753
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• 2005

Among processes to manufacture parts from footwear materials like upper leathers, one of the most essential processes is the cutting one optimally arranging lots of parts on raw footwear materials and cutting. A new nesting strategy was proposed for the 2-dimensional part layout by using a two-stage approach, where which can be effectively used for water jet cutting. In the initial layout stage, a SOAL(Self-Organization Assisted Layout) based on the combination of FCM(Fuzzy C-Means) and SOM was adopted. In the layout improvement stage, SA(Simulated Annealing) based approach was adopted for a finer layout. The proposed approach saves much CPU time through a two-stage approach scheme, while other annealing-based algorithm so far reported fur a nesting problem are computationally expensive. The proposed nesting approach uses the stochastic process, and has a much higher possibility to obtain a global solution than the deterministic searching technique. We developed the automatic nesting software of NST(ver.1.1) software for footwear industry by implementing of these proposed algorithms. The NST software was applied by the optimized automatic arrangement algorithm to cut without the loss of leathers. if possible, after detecting damage areas. Also, NST software can consider about several features in not only natural loathers but artificial ones. Lastly, the NST software can reduce a required time to implement generation of NC code. cutting time, and waste of raw materials because the NST software automatically performs parts arrangement, cutting paths generation and finally NC code generation, which are needed much effect and time to generate them manually.

• 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.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.2 no.2
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• pp.39-43
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• 2001

This paper aims to manufacturing of connecting rod die using CAD/CAM systems. CAD/CAM systems are consist of CAD(MDT4.0), CAM(Z-MASTER) software and CNC milling machine. CAM software is purpose to G-code generation for CNC programming. Then CAM software and CNC milling machine are connect to RS-232-C cable for data network.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.4
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• pp.91-97
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• 1998

Design methodology of Interactive Measuring Part Program Generating Tools(IMPPGT) realized on the FANUC 15MA using touch trigger probes and interactive macro functions of the CNC was described in this paper. Measuring G codes were designed according to geometric form, precision attributes, relations between parts, datum hierarchies, and relevant technological data by using measuring arguments. Menu driven measuring and inspection functions of the IMPPGT were studied and implemented on the CNC through the macro executor and ROM writer. Using the developed measuring G code system on the machine tool, untended measurement and inspection operation was able to be realized in precision FMS lines.

• Journal of Welding and Joining
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• v.12 no.2
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• pp.11-19
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• 1994

레이저 가공기술은 재료가공 분야에서 넓은 응용분야를 가지고 있으며, 특히 절단, 용접, 열처리 등의 가공분야에서 고정밀도와 자동화의 용이성으로 인해 생산성이 높은, 고부가가치의 첨단응용 기술로 부각되고 있다. 특히 레이저절단은 타 절단법에 비교되는 절단정도, 열영향, 생산성, 작업 환경등의 각종 우위성으로 박판 및 후판절단분야에서 급속한 보급을 보이기 시작하였다. 현재 대 부분의 레이저 가공기는 CNC화 되어가고 있는 추세이며, 레이저 절단의 경우 생산성증대 및 고 정밀화를 위하여 CAD/CAM인터페이스에 의한 자동화가 필연적인 상황이다. 뿐만아니라 고출력 레이저 발전기를 가공 기본체에 탑재한 탑재형 레이저가공기의 출현으로 대형부재의 절단이 가능 하게 되었으며, 더불어 절단공정의 무인화를 지향하는 각종 시스템이 개발되고 있다. 이와 같은 무인화, 생산성증대, 작업시간단축과 러닝 코스트 및 재료의 절감을 위한 노력의 일환으로 컴 퓨터에 의한 자동 및 반자동 네스팅 시스템의 개발을 들 수 있다. 레이저에 의한 2차원 절단응 용분야에서의 네스팅작업은 설계가 끝난 각 부품의 절단작업의 전단계로서 수행되며, 일반적으로 네스팅공정이 완료되면 절단경로를 결정하고 가공조건과 함께 수치제어공작기계의 제어에 필요한 NC코드를 생성하게 된다. 최근에는 이와 같은 네스팅 시스템이 일부 생산현장에 적용되고 있 으나 이러한 시스템들의 대부분이 외국에서 개발된 것을 수입하여 사용하는 실정이다. 2차원 패턴의 최적자동배치문제는 비단 레이저 절단과 같은 열가공 분야에서 뿐만 아니라 블랭킹 금형, 의류, 유리, 목재등 여러분야에서 응용이 가능하며 패키지의 국산화가 시급한 실정이다. 네스 팅작업은 적용되는 분야에 따라 요구사항과 구속조건이 달라지며 이로 인해 알고리즘과 자료구 조도 달라지게 되나 공통적인 목표는 주어진 영역안에서 겹침없이 배치하면서 버림율을 최소화 하는 것이다. 지난 10여년간 여러 산업의 응용분야에서는 네스팅시스템의 도입이 활발하게 이 루어지고 있는데 수동에 반자동 및 자동에 이르기까지 다양하나 자동네스팅시스템의 경우 배치 효율의 신뢰성이 비교적 부족하기 때문에 아직까지는 생산현장에서 기피하는 실정이다. 배치알 고리즘의 관점에서 볼 때 이러한 문제들은 NP-complete문제로 분류하며 제한된 시간안에 최적의 해를 구하기가 가능한 조합 최적화 문제로 알려져 있다. 따라서 이 글에서는 레이저 절단분야 에서의 네스팅시스템에 관한 개요와 최근의 연구동향 그리고 몇 가지 전형적인 네스팅 알고리 즘들을 소개하고 비교분석을 통해 개선점을 간략하게 논의하고자 한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.1C
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• pp.102-110
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• 2004

In this paper, we propose a VLSI structure of real-time image compression and reconstruction processor using 2-D discrete wavelet transform and implement into a hardware which use minimal hardware resource using ASIC library. In the implemented hardware, Data path part consists of the DWT kernel for the wavelet transform and inverse transform, quantizer/dequantizer, the huffman encoder/huffman decoder, the adder/buffer for the inverse wavelet transform, and the interface modules for input/output. Control part consists of the programming register, the controller which decodes the instructions and generates the control signals, and the status register for indicating the internal state into the external of circuit. According to the programming condition, the designed circuit has the various selective output formats which are wavelet coefficient, quantization coefficient or index, and Huffman code in image compression mode, and Huffman decoding result, reconstructed quantization coefficient, and reconstructed wavelet coefficient in image reconstructed mode. The programming register has 16 stages and one instruction can be used for a horizontal(or vertical) filtering in a level. Since each register automatically operated in the right order, 4-level discrete wavelet transform can be executed by a programming. We synthesized the designed circuit with synthesis library of Hynix 0.35um CMOS fabrication using the synthesis tool, Synopsys and extracted the gate-level netlist. From the netlist, timing information was extracted using Vela tool. We executed the timing simulation with the extracted netlist and timing information using NC-Verilog tool. Also PNR and layout process was executed using Apollo tool. The Implemented hardware has about 50,000 gate sizes and stably operates in 80MHz clock frequency.