• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.1004-1011
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• 1996

This paper covers the technology developmental stage work for the automatic ammunition loading system mainly focusing on the controller design of the electro-hydranlic type direct drive multi-axis manipulator. Mathematical model of the plant derived and PIDM servo-controller structured. Comparative study between the analytical and experimental work has been carried out to help understand the response property of the direct dine multi-axis robot. In the direct drive robot, non-negligible amount of disturbance and load Induced dynamics variation are transmitted to the drive axis and nonlinearity is highly observed. Thereupon a robust controller Implementing time-delay control law is proposed, and computer simulation confirms the possibility for the time-delay control application against the unpredictable disturbance and load-Induced dynamics variation.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.6
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• pp.15-22
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• 2014

With a conventional positioning apparatus, it is very difficult simultaneously to achieve desired driving ranges and precision levels at the sub-micrometer level. Generally, a lead screw and friction drive have been used as servo control systems. These have large driving ranges, and high-speed positioning is feasible. In this study, we present a global servo system controlled by a laser interferometer acting as a displacement measurement sensor for achieving positioning accuracy at the sub-micrometer level.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.6
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• pp.119-126
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• 2000

In this paper. a simple high-speed crash test rig for members of vehicle was developed for the improvement of crashworthiness of vehicle's side rail. The cart hanging the specimen is accelerated up to 35 mph by the force of freely dropping weight and 1:3 accelerating pulleys. The cart with shock absorbers travels on the rail roads, so it does not transfer any additional vibration to the specimen. To measure the test results, two types of accelerator are considered. the one is a strain gage type and the other is a piezo type. The test rig is rated good to test the specimen like a side rail of vehicle as developing the vehicle's structures in the early design stage.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.10a
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• pp.196-201
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• 2001

This study reveals the thin sheet metal process with multi-forming die that the name is progressive die, as a pilotless type, also high precision production part is made. They require analysis of many kinds of important factors, i.e. theory and practice of metal press working and its phenomena die structure, machining condition for die making, die material, heat treatment of die components, know-how and so on. In this study, we designed and constructed a multi-forming progressive die as a bending and drawing working of multi-stage and performed through the try out for thin sheet metal. Out of the characteristics of this paper that nothing might be ever seen before such as this type of research method on the all of processes of thin and high precision production part.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.9
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• pp.687-694
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• 2014

The mount suppliers are providing limited information on the dynamic characteristics of the mounts to some designers and some manufacturers of the high-precision machines. In this technical study, the experimental review was carried out about dynamic characteristics of five kinds of commercial passive mounts sold in the market. The dynamic characteristics, natural frequency and damping ratio, extracted from experimental tests were compared to the materials supplied by mount makers. In order to predict the performance of the high-precision machines with mounts, exact values of the dynamic characteristics of mounts should be used in the stage of numerical analysis.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2000.10a
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• pp.97-100
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• 2000

Today deep drawing and ironing are the major process in manufacturing of battery case used in cellular phone from aluminum. The same technology is utilized in manufacturing of steel or aluminum cans for components of medical instrument, portable PC, walkman and so on. Most of these processes require multi-stage ironing following the deep drawing and redrawing processes. The practical aspects of this technology are well known and gained through extensive experiment and production know-how. However, the fundamental aspects of theses processes are relatively less known. Thus, it is expected that process simulations using FEM techniques would provide additional detailed information that could be utilized to improve the process condition. This paper illustrates the application of process modeling to deep drawing and redrawing operations for High Precision Rectangular Battery Case. A commercially avaliable finite element code LS-DYNA3D was used to simulate deep drawing and redrawing operations.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.471-474
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• 2001

Recently, due to demands of faster speed and extra features for the chip mounters, there has been ever-demanding needs for the basic technology. Until four or five years ago, chip mounters placing 0.3sec/chip were considered to be in the high speed category, but since then it has become a borderline for categorizing high speed machines capable of placing 0.1sec/chip. In this study, in order to analyze the vibration of head generated by the dynamic behavior of x-frame, FEM model is composed and modal analysis is performed to identify the dynamic characteristics of the structure. Those results are compared with the modal test in order to verify the model. In this paper, Several other factors, such as definition of dynamic accuracy, static accuracy and tolerance of the axis settling range, that might affect the dynamic behavior the head are discussed.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.2
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• pp.99-106
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• 1998

In this paper, we have constructed an expert system for semiconductor chip encapsulation which combines a knowledge-based system with CAE software. The knowledge-base module includes heuristic and pre analysis knowledge for evaluation and redesign. Evaluation of the initial design and generation of redesign recommendations can be developed from the rules as applied to a given chip package. The CAE programs can be used for simulating the filling and packing stage of encapsulation process. The expert system is a new tool which enables package design or process conditions with high yields and high productivity.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.56-61
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• 2003

본 논문은 초정밀 가공기에 적용 가능한 6자유도의 운동이 가능한 초정밀 스테이지의 설계를 기술한다. 본 초정밀 스테이지는 특히, 광학을 이용한 가공기와 절삭력이 작은 가공기에 적합하다. 스테이지는 장행정 · 단행정 스테이지로 구성된 이중 서보를 채택한다 장행정 스테이지는 초정밀 운동에 방해가 되는 운동을 줄이며 높은 효율을 갖는 다극 자석 배열을 이용한 선형모터를 사용한다. 그리고 단행정 스테이지는 장행정 스테이지와의 기계적 결합에 의한 구조적 영향성을 없애는 개념을 적용할 수 있는 보이스 코일 모터을 이용한다. 그리고 각 구동부는 최상의 성능을 유지할 수 있도록 최적설계를 수행한다.

• The Journal of Korea Robotics Society
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• v.4 no.3
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• pp.225-232
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• 2009

In the high precision robot systems, the most popular tasks may be handling of micro-scale objects on a surface such as a micromanipulation robot system. In handling of micro-scale objects, the stiction effect becomes a fundamental issue since the micro-contact mechanics dominates the micromanipulation robot system. In the paper, a theoretical non-stick condition derived from the micro-contact mechanics is carried out for the propose of micro-scale object manipulation. To verify the non-stick condition, a micro-manipulation robot system equipped with a high precision stage system and a microscope system is developed. Experimental results show that the proposed non-stick condition guarantees successful micro-scale object manipulation.