• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2006.10a
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• pp.145-149
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• 2006

반도체의 고집적화와 LCD의 대형화로 인해 웨이퍼 및 LCD 검사용 스테이지의 성능 향상이 요구된다. 본 논문에서는 고속의 검사속도, 서브마이크론의 검사 정밀도, 그리고 대행정 구동을 위한 이중 서보 시스템을 제안하였다. 이중 서보 시스템은 선형모터로 구동되고 공기베어링으로 가이드 되는 조동 구동부와 보이스 코일 모터(VCM)로 구동되고 공기베어링으로 가이드 되는 미세 구동부로 구성된다. 검사 효율을 향상시키기 위한 고속 세틀링을 위한 제어기로서 시간 최적 제어 기법과 시간 지연 제어기를 결합한 모드 변경 제어기를 제안하고 이중 서보 시스템에 구현하여 성능을 평가하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.162-162
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• 2004

위치결정 기술은 초정밀 미세 기술의 발달과 제품의 소형화, 경량화에 대한 요구가 늘어나면서 고정밀화가 가속화되어 현재는 나노미터 수준의 위치정밀도를 요구하고 있다 현재 널리 사용되어지는 표면형상 측정기인 AFM은 분해능과 정밀도는 우수하지만, 이송 스테이지의 제한으로 측정영역이 좁은 단점이 있다. 이를 극복하기 위해서 이중서보를 사용한 방식들이 많이 제안되어 왔고 단일 서보를 사용하는 방식들도 연구되고 있다. 하지만 이중서보 방식은 여러 가지 액츄에이터와 컨트롤러를 사용해야하므로 제어알고리즘과 시스템이 복잡해지는 단점을 가지고 있다.(중략)

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.6
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• pp.612-619
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• 2004

Servo motor systems with ball-screw and timing-belt are widely used in NC, robot, FA and industrial applications. However, the nonlinear friction torque and damping effect in machine elements reduce the control performance. Especially tracking errors in trajectory control and very low velocity control range are serious due to the break-away friction and Stribeck effects. In this paper, a new double speed controller is proposed for compensation of the nonlinear friction torque. The proposed double speed controller has outer speed controller and inner friction torque compensator. The proposed friction torque compensator compensates the nonlinear friction torque with actual speed and speed error information. Due to the actual information for friction torque compensator without parameters and mathematical model of motor, proposed compensator is very simple structure and the stability is very high. The proposed compensator is verified by simulation and experimental results.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.3 s.96
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• pp.154-163
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• 1999

In this paper, an ultra precision positioning system has been developed using dual servo loop control. For positioning system having long distance with ultra precision , the combination of global stage and micro stage was required. A servo motor based ball screw is used as a global stage and the piezo actuator as a micro stage. For the improvement of positional precision, the digital Chebyshev filter is implemented in the developed to dual servo system. Therefore, the positional repeatability has been achieved within ${\pm}$ 10 mm, and this technique can be applied to develop precision semiconductor equipments such as lithography steppers and probers.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.437-441
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• 1995

In this paper, the ultra precision positioning system for servo motor and piezo actuator using dual servo loop control has been developed. For positioning system having long distance with ultra precision, the combination of global stage and micro stage is required. Servo moter and ball screw are used as a master stage and piezo acuator as a fine stage. By using this system, an positional precision witin .+-. 30nm has been achieved at dual servo loop control. When using micro stage, an positional precision within .+-. 10nm has been achieved. This result can be applied to develop semiconductor equipment such as wafer stepper.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1309-1314
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• 2003

The high precision positioning mechanism is used in various industrial fields. It is used in semiconductor manufacturing line, test instrument, Bioengineering, and MEMS and so on. This paper presents a positioning mechanism with dual servo system. Dual servo system consists of a coarse stage and a fine motion stage. The course stage is driven by VCM and the actuator of fine stage is the PZT. The purposes of dual servo system are stability, higher bandwidth, and robustness. Lead compensator is applied to this control system, and is designed by PQ method. Designed compensator can improve property of positioning mechanism.

• Journal of the Semiconductor & Display Technology
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• v.2 no.2
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• pp.31-37
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• 2003

This paper presents a measurement system of mechanical property using dual servo system. There are many kinds of method to measure material properties such as tensile test, indention and bending test. It is highly required to measure the properties of nano-sized material and structure. However, It is need more accurate measurement system, more stable and frequency response than conventional test. In this paper, we designed the dual servo system for a measuring instrument The dual servo system consisting of a coarse stage and a fine motion stage with VCM and PZT is proposed. Mechanical mechanism is designed with the leaf spring type of flexure hinge joint. Lead compensator is applied to this control system, and is designed by PQ method.

• Journal of Advanced Navigation Technology
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• v.13 no.5
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• pp.705-713
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• 2009

This paper proposes CORBA-based visual servoing system of humanoid robot. To effectively control the humanoid robot which is connected to network, it needs to define necessary services for visual servoing as distribution object, and realize them in the middleware. For realizing it following services should be addressed. Naming service for searching a necessary service with unique name assigned to each object, image service for supplying image obtained from stereo camera. In the experiment, we show the result of balloon tracking and bursting that the robot tracks balloons as target objects in the real time, and if a balloon stop for a certain time, then the robot bursts the balloon.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.12
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• pp.965-971
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• 2003

To reach high areal density, less track pitch is expected and more servo bandwidth is required. One approach to overcoming the problem is by using dual stage servo system. For this system. we have suggested new milliactuator based on the shear mode of piezoelectric elements to drive the head suspension assembly. In this paper, we introduce milliactuator and controller design method, PQ method. PQ method reduces the controller design problem for DISO (dual-input/single-output) systems to two standard controller design problems for SISO ( single-input/single-output) problems. The first part of PQ method directly addresses the issue of actuator output contribution, and the second part allows the use of traditional loop shaping to achieve the overall system performance. This paper shows how to employ the PQ method to meet aggressive close-loop performance specifications for a disk drive system with a VCM and piezoelectric milliactuator.

• Journal of the Institute of Convergence Signal Processing
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• v.8 no.3
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• pp.222-226
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• 2007

In this paper we composed the dual fuzzy rules using each region of specific points and $e-{\Delta}e$ phase plane In order to make dual fuzzy rule base. We composed the fuzzy control rules which can decrease rise time, delay time, maximum overshoot than basic fuzzy control rules. proposed method is alternately use at specific points of $e-{\Delta}e$ phase plane with two fuzzy control rules that is one control rule occruing the steady state error in transient region and another fuzzy control rule use to decrease the steady state error and rapidly converge at the convergence region. Also, two fuzzy control rules in the $e-{\Delta}e$ phase plane decide the change time according to response characteristics of plants. In order to confirm thef proposed algorithm. As the results of experiments through the hydraulic servo motor control system with a DSP processor, We verified that proposed dual fuzzy control rules get the good response compare with the basic fuzzy control rule.