• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.92-97
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• 1994

The there axis CNC grinding machine tool for ultra-precison mirror surface grinding of advanced materials such as ceramics and other hard and brittle materials was designed and manufactured. The grinding machine is composed of the air spindle, the high damping resin concrete bed, and the three axis CNC controller with the high resolution AC servo motor. To investigate the dynamic properties of the grinding machine, the natural frequencies of the spindle and the headstock were experimentally measured. The truing method using the break truer to revise the shape of the metal bonded diamond wheel was developed. Form the results of the machining using the prototype three axis CNC grinding machine manufactured, the mirror surface were achieved.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 A
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• pp.215-217
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• 1997

본 논문에서는 유한요소 해석을 통한 리액턴스 보정 방법을 제안한다. 동기 리액턴스는 대상 전동기의 유한요소 해석을 통하여 자계 분포를 계산하여 구할 수 있고 엔드 누설 리액턴스는 3차원 유한요소 해석의 결과로부터 계산하여 보정한다. 제안된 보정 과정을 추가한 자기 등가회로법으로 교류 서보 전동기를 해석한 결과와 실험치를 비교하여 본 논문의 해석 방법의 타당성을 확인한다. 이러한 연구를 통해서 교류 서보 전동기 뿐 아니라 일반 전동기를 해석함에 있어서 리액턴스를 보다 정확히 고려할 수 있고 고정밀의 전동기를 설계하는 데에도 유용하게 사용될 수 있을 것이다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1450-1452
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• 2005

AC Servo system has been implemented to semiconductor equipments system for their requirements of the high resolution control. This paper is based on the newly produced DSP TMS320F2812 which has the performance of fast processing speed, 150 MIPS, and rich peripheral interface. The implemented system has been developed for the position control that also has speed and current control as inner loops. The controller implemented a high precision position control system with SVPWM and digital PI control and using high resolution rotary encoder.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 추계학술대회논문집
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• pp.534-539
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• 2000

A flexible rotating beam test bed has been developed for experimental verification of flexible rotating beam dynamics and vibration. It consists of a flexible arm, harmonic driver reducer, ac servo motor and DSP board with PC. To capture the motion induced stiffening effects of the flexible rotating beam, substructuring model has been established in multibody dynamics simulation. Substructuring model provides better results comparing with experimental data.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 A
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• pp.59-61
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• 1995

This paper presents the cogging torque analysis of the permanent magnet type AC servo motor which have the closed slot structure. Generally, existence of the slot opening causes the cogging torque. But the cogging torque exists in this type motor(having closed slot structure) because the bridge part is saturated by the rotor flux. In this paper, the finite element analysis is used to calculate the cogging torque and the rated torque. As the size of the bridge part-the thickness and the width-changes, the cogging torque and the rated torque are obtained repeatedly like as upper procedures. Finally, the trends of the cogging torque and the rated torque versus the size of the bridge part are obtained from this analysis procedures. By this approach, the optimal geometry of the bridge part can be found which minimize the cogging torque satisfying the required value of the rated torque.

• 수산해양기술연구
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• 제36권3호
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• pp.257-265
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• 2000

본 논문에서는 BLDC 서보모터의 속도 제어성 향상을 위해 속도제어계에 2자유도 적분형 최적 제어법을 적용하고 그 결과를 기존의 PI제어계 및 2자유도 PI제어계와 비교하였다. 2자유도 적분형 최적제어법은 PI제어법이 갖는 지령치 추종특성과 외란 억제특성간의 트레이드오프 문제를 해결하고, 제어계의 최적성을 확보하고자 도입되어졌으며, 시뮬레이션과 실험을 통해 그 유효성을 고찰하였다. 시뮬레이션을 통해 얻은 결과는 다음과 같다. (1) 2자유도 적분형 최적제어계는 PI제어계에 비해 양호한 지령치 추종성과 외란 및 모델링 오차제거 특성을 보였다. (2) 2자유도 적분형 최적제어계는 제어파라미터인 하중행렬 Q, R 및 W에 대한 제약요건이 없을 경우, 모터의 정격조건 하에서 이들을 적절히 설정함으로써 2자유도 PI제어계보다도 양호한 지령치 추종성과 외란 및 모델링 오차 제거 특성을 얻을 수 있다. (3) 2자유도 적분형 최적제어계는 인가전압 및 전류의 크기를 2자유도 PI제어계의 그것과 동일하게 제약할 경우 2자유도 PI제어계에 비해 지령치 추종에 관한 정정시간 외에는 그다지 우수한 성능을 보이지 않았다. 또한, 실험을 통해 고찰한 PI 및 2자유도 PI제어계의 속도추종성능은 시뮬레이션 결과와 거의 동일하였다. 2자유도 적분형 최적제어계에 대한 실험결과는 논문에 나타내지 못하였으나, PI및 2자유도 PI제어계의 실험결과에서 알 수 있듯이 2자유도 적분형 최적제어계도 시뮬레이션 결과와 같은 경향을 보일 것으로 사료된다. 따라서, 본 논문에서 검토된 방법은 기존의 PI 제어계가 갖는 지령치 추종과 외란억제의 트레이드오프 문제를 상당부분 해결 가능할 것으로 보인다. 또한, 일정의 부하외란 및 모델링 오차내에서는 2자유도 PI제어계 보다 나은 제어성능을 보여 BLDC 모터의 속도 제어성 향상에 기여할 수 있을 것으로 기대가 된다. 향후, 2자유도 적분형 최적제어계의 실험결과를 통한 엄밀한 제어성능검증과 스텝외란 외의 주기성 외란 인가시 2자유도 적분형 최적제어계의 외란제거 방안 등이 검토되어야 할 것으로 사료된다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2000-2003
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• 2003

In recent years, robots have been used widely in industrial field and have been expanded as a result of continuous research and development for high-speed and miniaturization. The goal of this paper is to design the serial manipulator through kinematic analysis and to control the position and orientation of end-effector with respect to time. In general, a structure of industrial robot consists of several links connected in series by various types of joints, typically revolute and prismatic joints. The movement of these joints is determined in inverse kinematic analysis. Compared to the complicated structure of parallel and hybrid robot, open loop system retains the characteristic that each link is independent and is controlled easily. AC servo motor is used to place the robot end-effector toward the accurate point with the desired speed and power while it is operated by position control algorithm. The robot end-effector should trace the given trajectory within the appropriate time. The trajectory of end-effector can be displayed on the monitor of general personal computer through Opengl program.

• 한국정밀공학회지
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• 제18권6호
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• pp.133-140
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• 2001

This paper suggests another system for a cutting force measuring tool in a milling process. Generally, tool dynamometer is taken into account for the most appropriate cutting force measuring tool in the analysis of cutting mechanism. However, high price and limited space make it difficult to be in-situ system for controllable milling process. Although an alternative method using AC current of servo-motor has been suggested, it is unsuitable for cutting force control because of small upper frequency limit and noise. The cutting force measuring system is composed of two load cells placed between the moving table bracket and the nut flange part of ballscrew. It has many advantages such as low cost and wide range measurement than tool dynamometer because of the built-in moving table and the low cost load cell. The static and dynamic model of the measuring system using imbeded load cell is introduced. Various Experiments are carried out to validate both models. By comparing the cutting forces from a series of end milling experiments on the tool dynamometer and the system developed in this paper, the accuracy of the cutting force measuring system is verified. Upper frequency limit is measured by the experiment of dynamic characteristics.

• 한국정밀공학회지
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• 제23권10호
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• pp.113-120
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• 2006

A cam profile CNC grinding machine is developed for manufacture of high precision contoured cams. The developed machine is composed of the high precision spindle using boll bearings, the high stiffness box layer type bed and the three axis CNC controller with the high resolution AC servo motor. In this paper, structural and modal analysis for the developed machine is carried out to check the design criteria of the machine. The analysis is carried out by FEM simulation using the commercial software, CATIA V5. The machine is modeled by placing proper shell and solid finite elements. And also, this paper presents the measurement system and experimental investigation on the modal analysis of a grinding machine. The weak part of the machine is found by the experimental evaluation. The results provide structure modification data for good dynamic behaviors. And safety of the machine was confirmed by the modal analysis of modified machine design. Finally, the cam profile grinding machine was successfully developed.

• Ocean and Polar Research
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• 제26권2호
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• pp.333-339
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• 2004

This paper is concerned with an experimental investigation about tractive performance of a tracked vehicle on extremely soft soil. A tracked vehicle model with principal dimensions of $0.9\;m(L)\;{\times}\;0.75\;m(B)\;{\times}\;0.4\;m(H)$ and the weight of 167 kg was constructed with a pair of driving chain links driven by two AC-servo motors. The tracks are configured with detachable grousers with variable span. Deep seabed was simulated by means of bentonite-water mixture in a soil bin of $6.0\;m(L)\;{\times}\;3.7\;m(B)\;{\times}\;0.7\;m(H)$. Slip of vehicle and driving torque of motor were measured with respect to experimental variables; grouser span, grouser chevron angle, driving speed, drawbar-pull weight, position of center-of-gravity and weight. $L_8$ orthogonal array is adopted for DOE (Design Of Experiment). The effects of experiment variables on traction performance are evaluated.