• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1998년도 제13차 학술회의논문집
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• pp.346-351
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• 1998

Cutting process has been automated due to progress of CNC and CAD/CAM, but polishing process has been only depended on experiential knowledge of expert. Polishing work for a curved surface die demands simple and repetitive operations but requires much time for its high precision. Therefore it is operated in the handiwork by skilled worker. However the workers intend to avoid gradually polishing work because of the poor environments such as dust and noise. In order to reduce the polishing time and solve the problem of shortage of skilled workers, it has been done some research for an automation of polishing. To automate the polishing process, a 2 axes polishing robot which is attached to a 3 axes machining center has been developed by our previous research. This automatic polishing robot is able to keep the polishing tool normal on the curved surface of die. Therefore its performance of polishing is improved because of always keeping the tool normal on the surface. In this paper, the smaller sized polishing robot is developed to improve polishing performance. And the controller for 2 axes polishing robot is developed. The controller is composed of TMS320C31 with high speed which is 40-ns instruction cycle time, RAM memory with 64K words, digital input with 64 bits, digital output with 32 bits, and D/A converter with 4 channels, which is 12 bits resolution. To evaluate polishing performance of this developed robot, polishing experiment for shadow mask was carried out.

• 한국정밀공학회지
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• 제16권9호
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• pp.179-190
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• 1999

To automate the polishing process, a polishing robot with two axes which is attached to a machining center with three axes has been developed by our previous research. This automatic polishing robot is able to keep the polishing tool normal to the curved surface of die and is able to maintain a constant pneumatic pressure. Therefore, in the case of a curved surface die, the surface roughness to be polished by the system with five axes is improved superior than the surface by a three-axis machining center. However, because the polishing robot was big and heavy, a polishing workspace was limited and then it was difficult to attach the robot to machining center. In this study, the smaller and lighter polishing robot than the previous has been designed to improve defects due to the magnitude and weight of the robot. And the sliding mode control ins applied to polishing robot to improve the tracking performance. To obtain switching parameters of sliding mode control, the signal compression method is used. Code separation program to separate the date for a three-axis machining center and a two-axis polishing robot from a five-axis NC data is improved for users to check conveniently the separated trajectory and to handle many data by using the graphic user interface. To evaluate the polishing performance of the developed robot, the polishing experiment for shadow mask was carried out. The result shows the automatic polishing robot has a good trajectory tracking performance and obtains a good polished workpiece efficiently under recommended polishing conditions.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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• pp.411-416
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• 2000

Cutting process has been automated by progress of CNC and CAD/CAM, but polishing process has been depended on only experiential knowledge of expert. To automate the polishing process, a polishing robot with w degrees of freedom which is attached to a machining center with 3 degrees of freedom has been developed. This automatic polishing robot is able to keep the polishing tool normal on the curved surface of die to improve a performance of polishing. Polishing task for a curved surface die demands repetitive operation and high precision, but conventional control algorithm can not cope with the problem of disturbance such as a change of load. In this research, a new sliding mode control algorithm is applied to the robot. The signal compression method is used to identify polishing robot system. to obtain an effect of 5 degrees of freedom motion, a synchronization between the machining center and polishing robot is accomplished by using M code of machining center. And also a trajectory for polishing the curved surface die by 5 degrees of freedom motion, a synchronization between the machining center and polishing robot is accomplished by using M code of machining center. And also a trajectory for polishing the curved surface die by 5 axes machining center is divided into data of two types for 3 axes machining center and 2 axes polishing robot. To evaluate polishing performance of the robot. various experiments are carried out.

• 한국공작기계학회논문집
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• 제15권1호
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• pp.32-38
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• 2006

The magnetic fluid polishing technique can polish the tool of complex shape, because the polishing method which polishes as compress the workpiece by the magnetism abrasives to arrange to the linear according to the line of magnetic force. Therefore, we producted the magnetic fluid polishing device in order that mirror like finishing processes the tool surface. In order to a polishing condition selection, polishing characteristic was estimated by polishing conditions which are magnetic flux density, polishing speed, grain size, magnetic fluid. The tool was polished to the selected polishing condition. The result to evaluate the polished tool's performance with the cutting force and tool wear, the polished tool's performance was improved compared with the tool not to polish.

• 한국정밀공학회지
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• 제28권8호
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• pp.929-935
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• 2011

As a deterministic finishing process for the optical parts having complex surface, machining performance of the magnetorheological(MR) fluid jet polishing of optical glass are studied and compared with a general water jet polishing. First, design of the jet polishing system which has the special electromagnet-nozzle unit for stabilizing the slurry jet based on MR fluid and the change of jet shape as magnetic field is applied are explained. Second, for the BK7 glass, machining spot and its cross section profile are analyzed and the unique effect of MR fluid jet polishing is shown. Third, both material removal depth and surface roughness are explored in order to investigate the polishing performance of MR fluid jet. With the same ceria abrasives and amount in the polishing slurries, MR fluid jet shows superior machining performance compared to water jet and the difference of material removal mechanism and its resulting performance are described.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.1275-1278
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• 1997

Cutting process has been automated by progress of CNC and CAD/CAM, but polishing process has been depended on only experiential knowledge of expert. To automate the polishing pricess polishing robot with 2 degrees of freedom which is attached to a machining center with 3 degrees of freedom has been developed. this automatic polishing robot is able to keep the polishing tool normal on the curved surface of die to improve a performance of polishing. Polishing task for a curved surface die demands repetitive operation and high precision, but conventional control algorithm can not cope with the problem of disturbance such as a change of load. In this research, we develop robust controller using real time sliding mode algorithm. To obtain gain parameters of sliding model control input, the signal compression method is used to identify polishing robot system. To obtain an effect of 5 degrees of freedom motion, 5 axes NC data for polishing are divided into data of two types for 3 axis machining center and 2 axis polishing are divided into data of two types for 3 axis machining center and 2 axis polishing robot. To find an efficient polishing condition to obtain high quality, various experiments are carried out.

• 한국정밀공학회지
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• 제16권4호통권97호
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• pp.163-177
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• 1999

Polishing work for a curved surface die demands simple and repetitive operations and requires much time while it demands also high precision. Therefore it is operated by a skilled worker in handiwork. However the workers avoid gradually a polishing work because of the poor environmental conditions such as dust and noise. In order to reduce the polishing time and to alleviate the problem of shortage of skilled workers, an automatic polishing robot system which is composed of a polishing robot with two degrees of freedom motion and pneumatic system is developed, and it is attached to machining center with three degrees of freedom. The system keeps the polishing tool vertically on the surface of die and maintains constant pneumatic pressure. The polishing robot with DSP(digital signal processor) controller is controlled by sliding mode control. A synchronization between machining center and polishing robot is accomplished by using M code of machining center. A performance experiment for polishing work is executed by the developed automatic polishing robot system. The result shows that the developed automatic polishing robot has a good performance and well polished workpiece surface is obtained.

• 한국생산제조학회지
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• 제25권2호
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• pp.112-117
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• 2016

In the construction industry, concrete polishing is used to grind and rub the surface of concrete grounds with polishing machines to increase the strength of the concrete after deposition. Polishing is performed manually in spite of the generation of dust and the requirement of frequent replacements of the polishing pad. The concrete polishing robot developed in this research is a novel polishing automation system for preventing the workers from being exposed to poor working environments. This robot is able to change multiple polishing tools automatically; however, the workers can conveniently replace the worn-out polishing pads with new ones. The mobile platform of the polishing robot employs omnidirectional wheels to enable a flexible motion even in small and complicated workspaces. To evaluate the performance of the developed concrete polishing robot, extensive experiments including square trajectory tracking, automatic tool changing, actual polishing, and path generation simulation were performed.

• 한국정밀공학회지
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• 제22권10호
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• pp.90-98
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• 2005

A monitoring system is necessary to make the polishing process more reliable in order to ensure the high quality and performance of the final products. Generally, AE (Acoustic Emission) is known to be closely related to the material removal rate (MRR). As the surface becomes rougher, the MRR and AE increase. Therefore, the surface roughness can be indirectly estimated using the AE signal measured during the polishing. In this study, an AE sensor-based monitoring system was fabricated to detect the very small AE signal resulting from the friction between a tool and a workpiece during polishing. The performance of this monitoring system was estimated according to polishing conditions, the relation between the level of the AE RMS and the surface roughness during the polishing was investigated.

• 한국전기전자재료학회논문지
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• 제20권10호
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• pp.839-845
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• 2007

In this paper, a polishing pad has been analyzed in detail, to understand surface phenomena of polishing process. The polishing pad plays a key role in polishing process and is one of the important layer in polishing process, because it is a reaction layer of polishing[1]. Pad surface physical property is also ruled by pad profile. The profile and roughness of pad is controlled by different types of conditioning tool. Conditioning tool add mechanical force to pad, and make some roughness and profile. Formed pad surface will affect on polishing performance such as RR (Removal Rate) and uniformity in CMP Pad surface condition is changed by conditioning tool and dummy run and is stable at final. And this research, we want to reduce break-in and dummy polishing process by analysis of pad surface and artificial machining to make stable pad surface. The surface treatment or machining enables to control the surface of polishing pad. Therefore, this research intends to verify the effect of the buffing process on pad surface through analysis of the removal rate, friction force and temperature. In this research, urethane polishing pad which is named IC pad(Nitta-Haas Inc.) and has micro pore structure, is studied because, this type of pad is most conventional type.