• Proceedings of the Acoustical Society of Korea Conference
• /
• 1984.12a
• /
• pp.107-112
• /
• 1984

수동 Wave-front curvature ranging 방법의 통계적성능에 대한 일반적 결과가 유도된다. 센서들의 비선형 및 부동간격 센서들의 운동효과로 인한 표적거리의 편의(bias) 및 편차9variance)가 센서간의 운동이 상관관계를 가지고 있을 때 유도된다. 이 논문은 센서운동이 정규분포(normal distribution)를 가지며 평균이 0, 같은 편차 및 투시할 수 있는 higher moment를 가지고 있다고 가정한다. 유도된 일반적 결과를 이용하여 거리편의 및 편차는 표적거리, 방위, 센서운동의 상관계수 및 방향각(heading)표준편차 변화에 대해 그림으로 나타나 있다. 표적거리가 센서간격보다 아주 큰 경우 센서간격이 감소할수록, 표적거리가 증가할수록, 거리편의 및 편차는 증가한다. 상관계수가 증가할수록 거리편의는 직선적으로 감소하며, 거리편차는 센서 방향각 오차가 클 때 최소가 되는 상관계수가 존재하며 이는 표적거리, 방위 및 센서간격의 복합함수이다.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.10a
• /
• pp.299-300
• /
• 2006

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.27 no.11
• /
• pp.92-102
• /
• 1990

A new method for determining the motion parameters (scale, rotation, translation) of 2-D image is introduced. It employs Hough transform that maps the straight lines in the input image to the points in the Hough space (HS). This method makes use of the relations between the motion of an object in input image and the translations of peak points in the HS and thus derives relating equations about motion parameters especially when scale changes are involved. The derived equations make is efficient and simple to estimate motion parameters of input image, even if the scale parameter of input image is varied. Performance of this approach on an aircraft image is provided in detail in the presence of noise.

• Journal of IKEEE
• /
• v.19 no.3
• /
• pp.335-341
• /
• 2015

Recently a demand for high precision absolute position transducer is increasing in order to control thickness in steel industry. LVDT (linear variable differential transformer) is widely used to measure the absolute position in the linearly moving cylinder under poor factory environment. In this paper we implement the three phase LVDT with a high resolution of one micron and L/D (LVDT to digital) converter. First we designed U, V, and W three phase signaling using FPGA. Second a pulse output algorithm is designed for position information with A and B phase waveforms. Finally the performance is compared with previous sensors. Experiments show that the linearity deviation error is 0.009788 [mm] and the average sinusoidal THD is 0.0751%, which means 2.2% and 33% more improved result than the previous sensors respectively.

• Proceedings of the KIEE Conference
• /
• 2003.10b
• /
• pp.171-173
• /
• 2003

기존의 선형 이송 시스템은 구동원으로 서보모터를 사용하고 있다. 서보 모터의 회전 운동을 직선운동으로 변환하기 위해서는 기계적인 동력전달 장치가 필요하며, 이는 위치 오차의 발생이나 주기적인 시스템의 유지보수의 필요성 등의 문제점을 야기한다. 본 논문에서는 단위 체적당 추력비가 기존의 모터에 비해 우수한 횡축형 선형전동기를 이용하여 LCD 공정에 사용되는 indexer 시스템의 선형 추진부에 적용하는 연구를 수행하였다. 실험결과 횡축형 선형전동기는 가속능력 최대 속도 및 위치결정 정밀도 등에서 indexer 시스템에 적용하기에 적합한 것을 검증하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1996.11a
• /
• pp.671-677
• /
• 1996

This paper proposes a study on the effects of motion errors for acceleration/ deceleration types. The proposed motion errors are consisted of two errors : one due to transient response of servomechanism and the other due to gain mismatching of positioning servo motor. They are derived from using laplace transformation for the block diagram of general purpose feed drive system. In order to minimize them, the paper proposes second order polynomial regression model by using orthogonal array method which describes one of experimental methodolgies. The validity and reliability of the study was veri lied on a vertical machining center equipped with FANUC 0MC through a series of experiments and analyses.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• v.2
• /
• pp.475-478
• /
• 2006

본 논문에서는 소형 무인항공기의 정확한 위치, 속도, 자세 정보를 제공하기 위해 저급의 MEMS IMU를 이용한 항법 시스템을 제안한다. 제안하는 시스템은 비행체의 직선운동과 회전운동을 측정할 수 있는 관성측정기와 위성신호를 수신하여 항체의 위치, 속도 정보를 제공하는 GPS 수신기, 지구 자기장 정보를 이용하여 방향각 정보를 제공하는 지자기 센서들로 구성되었다. SDINS와 약결합 방식의 칼만필터를 이용한 항법 시스템은 초기정렬 알고리즘과 센서 오차 보상 알고리즘, 자력계 보상 알고리즘 및 복합항법 알고리즘으로 나뉘며, 설계된 항법 알고리즘들은 시뮬레이션과 차량 실험을 통해서 성능을 분석하였다.

• Journal of the Korean Society for Precision Engineering
• /
• v.31 no.5
• /
• pp.423-430
• /
• 2014

In this study, the five-DOF motion at ultra-precision linear stage under static and dynamic conditions are evaluated through the extending application of ISO 230-2. As the performance factors, the bi-directional accuracy and repeatability of the five-DOF motion are quantitatively evaluated with the measurement uncertainties which are determined using the standard uncertainty of equipment used in experiment. The motion under static condition are analyzed using geometric errors. The five geometric errors except the linear displacement error are measured using optimal measurement system which is designed to enhance the standard uncertainty of geometric errors. In addition, the motion under dynamic conditions are analyzed with respect to the conditions with different feed rate of the stage. The experimental results shows that the feed rate of stage has a significant effect on straightness motions.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.21 no.10
• /
• pp.1718-1729
• /
• 1997

This paper describes motion errors due to acceleration and deceleration types of servo motors in NC machine tools. Motion errors are composed of two components : one is due to transient response of a servomechanism and the other comes from gain mismatching of positioning servo motors. It deals with circular interpolation to identify motion errors by using Interface card. Also in order to minimize motion errors, this study presents an effective method to optimize parameters which are connected with motion errors. The proposed method is based upon a second order polynomial regression model and it includes an orthogonal array method to make the effective results of experiments. The validity and reliability of the study were verified on a vertical machining center equipped with FANUC 0MC through a series of experiments and analysis.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.9 no.6
• /
• pp.553-559
• /
• 2004

The servo motor is used for the driving power source of the conventional linear conveyor system. The mechanical power transfer system is needed for converting the circular to the linear operation. But this system causes some problems of position error, the necessity of the periodical maintenance. In this paper the study on application of transverse flux linear motor(TFLM) is carried out for the indexer system of LCD processing because TFLM has much thrust per a volume than the conventional motor. TFLM is suitable system for the indexer system because of capacity of acceleration, maximum speed and precision of the position, etc.