• 한국항공우주학회지
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• 제45권5호
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• pp.393-400
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• 2017

본 논문에서는 회전익 무인항공기의 조종성 평가를 수행하기 위한 가상모의시험용 프로그램을 MATLAB GUIDE(Graphic User Interface Development Environment)를 활용하여 개발하였다. ADS-33E에 기반을 둔 조종성 평가 프로그램은 비행제어시스템을 개발하고 조종성을 평가하는 데에 있어 시간과 비용을 경감시킬 수 있을 것으로 사료된다. 또한, Linear Quadratic Regulator(LQR)기반의 Linear Quadratic Tracker with Integrator(LQTI) 자세제어기를 BO-105C 회전익 항공기에 적용하여 조종성을 평가하고 Q와 R의 가중치에 따른 조종성에 대한 경향을 분석하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.463-464
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• 2010

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 추계학술대회 논문집
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• pp.527-528
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• 2010

• 한국레이저가공학회지
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• 제11권1호
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• pp.1-6
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• 2008

We proposed new light guide panel (LGP) fabrication method exploiting laser-processed inner scatterers and surface pattern. The proposed method has achieved LGP performance improvement in both brightness and uniformity. The inner scatterers and surface pattern of grid type were fabricated with a 2nd harmonic Nd:YAG pulse laser engraving system and a $CO_2$ laser scanning system, respectively. In the implementation of LGP, inner scatterers was arranged in accordance with linear or curved pattern with changing density and surface pattern was engraved on the surface of an inner-scatterers embedded LGP. The increase of scatterers' density and the use of surface patterns in both linear and curved pattern provided high luminance and uniformity enhancement. While thecurved pattern incorporated with increased scatterers' density and surface patterns yielded brightness improvement with preserving good uniformity, the linear pattern showed highly localized brightness near the light entrance of the LGP. We can also observe that the uniformity was mainly determined by pattern of inner scatterers, and the brightness was improved by the higher density and the utilization of surface patterns. From the results, the use of laser-processed inner and surface patterns can be a potential alternative for efficient and simple LGP fabrication method.

• 전기학회논문지
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• 제60권1호
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• pp.63-70
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• 2011

This paper presents the design and operating characteristics of the novel cylindrical linear motor which is designed for the long stroke XY stage. In the long stroke structure, the air gap is changed by the distortion and bending effects, and it makes additional position error in the XY stage. In order to consider the distortion and bending effects of the long stroke, the field part of the cylindrical linear motor is designed as an open structure, and the stroke is supported by the bridge guide which is positioned in the open field part. The mechanical bridge guide can reduce the bending effects of the stroke and can keep a constant air gap. The detailed design process of the proposed cylindrical linear motor is presented in this paper. The proposed motor is analyzed by the 3D FEM technology. The practical XY stage which uses the proposed motor is tested to verify the propose novel cylindrical linear motor. The FEM and experimental results show the effectiveness of the proposed motor.

• 대한치과보철학회지
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• 제27권2호
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• pp.11-36
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• 1989

Mandibular movements are guided mainly by three determinants, namely the two posterior controls (the Temporomandibular joints) and the anterior control (the incisal guidance). The aim of this study was to evaluate the incisal guide angle in effort to reconcile a patient's condylar guide angle and incisu guide angle, to develop criteria for incisal guidance in clinical practice. 48 subjects (male 33, female 15) with intact intercuspation, without past history and symptoms of stomatognathic system, were selected for this study. All of the subjects had not anterior prostheses. The sagittal condylar guide angles and incisal guide angles were measured and estimated statistically by cephalogram and articulator (Whip-Mix 8500A). The results of this study were as follows: 1. Average of condylar guide angle was 43.33 degree by cephalogram, and was 35.18 degree by articulator. 95% confidence interval was from 40.43 to 46.23 degrees in cephalogram and was from 32.98 to 37.38 degrees in articulator. 2. Average of incisal guide angle was 51.51 degree by cephalogram, and was 44.11 degree by articulator. 95% confidence interval was from 49.12 to 54.95 degrees in cephalogram and was from 40.67 to 47.56 douses in articulator. 3. Difference between condylar and incisal guide angle was 8.18 degree by cephalogram, and was 8.94 degree by articulator. 95% confidence interval was from 4.61 to 11.74 degrees in cephalogram and was from 4.90 to 12.98 degrees in articulator. 4. In case of the incisal guide angle steeper than condylar guide angle, subjects were 69% (33 of 48) in cephatogram and 75% (36 of 48) in articulator. 5. By the multiple regression equation, condylar guide angle was more influenced by the anterior teeth. 6. When the mandible protrudes from the intercuspal position to the edge to edge position the incisal linear movement was 4.18mm (S.D.:1.30mm) and the condylar linear movement was 4.38mm (S.D.:1.26mm).

• 한국정밀공학회지
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• 제19권5호
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• pp.139-148
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• 2002

Motion errors of linear motion guideway are analyzed theoretically in this paper. For the analysis, an new algorithm predicting motion errors of bearing and guideway is proposed using the Hertz's elastic deformation theory. Accuracy averaging effect can be calculated quantitatively by analyzing relationship between motion errors of guideway and spatial frequency of rail form error. Influences of design parameters on the motion errors including the number of balls, preload, ball diameter, bearing length and the number of bearings are analyzed. As it is difficult to measure the rail form error, experimental results are compared with results analyzed by the equivalent analysis method which evaluate the motion errors of guideway using the measured errors of bearing. From the experimental results, it is confirmed that the proposed analysis method it effective lo analyze the motion errors of linear motion bearing and guideway.

• 한국생산제조학회지
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• 제22권6호
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• pp.996-1002
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• 2013

This study addresses the development of a full duplex robotic system for transferring flat-panel display glass. We propose to accomplish this using a bidirectional linear transfer mechanism in place of the conventional rotary transfer mechanism. The developed full duplex robot comprises a driving part that carries the glass panel laterally, vertical part that can be moved up and down by means of a ball screw and linear motion guide arrangement, and hand part that slides by the cylinder of the driving part along the guide rail with a V-guide bearing attached to the bottom of the support. In addition, an alignment part prevents the hand part from derailing and holds the hand part while the driving part moves horizontally. The full duplex robot lifts and drives a glass panel directly while transferring it to the buffer and does not require rotational motion. Therefore, both transferring and stacking are realized with a single device. This device can be used in existing industrial facilities as an alternative to existing industrial robots in current as well as future process lines. The proposed full duplex robot is expected to save considerable amounts of time and space, and increase product throughput.

• 한국정밀공학회지
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• 제21권12호
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• pp.174-181
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• 2004

Ultra precision positioning mechanism has widely been used on semiconductor manufacturing equipments, optical spectrum analyzer and cell manipulations. Ultra precision positioning mechanism is consisted of several actuators, sensors, guides and control systems. Its efficiency depends on each performance of components. The object of this study is to design, analysis and manufacture all of the inchworm linear motor system, which is one of the equipments embodied in ultra precision positioning mechanism. Inchworm linear motor system is consisted of a controller system and an inchworm linear motor, and its driving form is similar to a motion of spanworm. A design and manufacture of inchworm linear motor, which is consisted of three PZT actuators, a rod, two columns and a guide plate, are performed. Minimizing the von-Mises stress of the hinge using Taguchi method and simulation by FEM software optimizes the structural design in a column of flexure hinge. The designed columns and guide plates are manufactured by a W-EDM and NC-milling. A controller system, which is an apparatus to drive inchworm linear motor, can easily adjust driving conditions by varying resonance frequency and input-output voltage of actuators and amplifiers. The performance of manufactured inchworm linear motor system is verified and valuated. In the future, inchworm linear motor system will be used to make a more precision positioning by reinforcing a sensor and feedback system.

• 한국정밀공학회지
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• 제26권8호
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• pp.112-118
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• 2009

A pressure rise is generated while air bearing stages are moving in high vacuum environment. This study analyzed this pressure rise phenomenon theoretically and verified it experimentally using two different kinds of stages - linear and rotary air bearing stages. Results indicate that the pressure rise was caused by additional leakage resulting from stage velocity, along with adsorption and outgassing of gas molecules from the guide rail surface. Though tilting of the stage due to acceleration and deceleration reached several micrometers, it had a negligible effect on pressure rise because the tilting time was very short. Therefore, a rotary air bearing stage showed much less pressure rise than a linear stage because the rotary stage theoretically has nothing to do with the above causes. Additional leakage caused by stage velocity was inevitable if the stage had movements, but pressure rise caused by adsorption and outgassing could be suppressed by improving the surface quality to reduce real surface area, and by coating the guide rail surface with titanium nitride (TiN) which has less adhesion probability of gas molecules. The results also indicate that the pressure rise increased when the air bearing stage operated under high vacuum conditions.