• 대한기계학회논문집A
• /
• 제35권6호
• /
• pp.599-607
• /
• 2011

본 논문에서는 별도의 외부 격리 구조물이나 추가 모터가 필요 없는 XY 선형 모션 스테이지를 위한 반발력 보상 시스템을 개발하였다. 개발된 시스템은 이동 가능한 마그넷 트랙, 스프링, 추가 질량을 포함한 자체 반발력 보상 구조를 가지고 있으며 이송용 모터 코일과 마그넷 트랙의 상대 위치를 검출할 수 있는 전용 센서를 개발하여 고정밀 추력 및 위치를 제어에 적용하였다. 먼저 반발력 보상 시스템을 모델링하고 모의 시험을 통해 이동 거리, 가속도, 하중, 허용 가능한 장비 크기와 같은 설계 요소를 최적화 하였다. 반발력 보상 시스템이 구비된 XY 모션 스테이지를 제작하였으며, 해당 시스템의 성능을 실험적으로 검증하였다. 실험결과 10m/$s^2$ 가감속 시에 85%의 반발력이 반발력 보상 시스템에 의해 흡수되었다.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2012년도 춘계학술대회 논문집
• /
• pp.1095-1096
• /
• 2012

• 한국정밀공학회지
• /
• 제31권10호
• /
• pp.929-934
• /
• 2014

Reaction force compensation (RFC) mechanism can relieve the vibration of base system caused by acceleration and deceleration of mover. In this paper, we propose a new passive RFC mechanism with a movable additional mass to reduce vibration of the system base as well as displacement of the magnet track. First, equation of motion for the new passive RFC mechanism is derived and simulated to tune design parameters such as masses and spring coefficients. Simulation results show that the vibration of the system base of the stage with the new RFC mechanism.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2012년도 춘계학술대회 논문집
• /
• pp.15-16
• /
• 2012

• 전력전자학회논문지
• /
• 제26권2호
• /
• pp.90-95
• /
• 2021

In contrast to AC grounding systems, the ground electrode in DC systems continuously maintains positive or negative polarity. Ground electrodes with (+) polarity proceeds by oxidation reaction. Thus, the DC current should flow opposite to the polarity of the leakage current flowing through the (+) ground electrode by using a compensation electrode, and the current flowing through the (+) ground electrode can be 0A. However, according to protecting the (+) ground electrode, the compensation electrode corrodes and gets damaged. Thus, the (+) ground electrode must be protected from corrosion, and the service life of the compensation electrode must be extended. As an alternative, the average value of the current flowing through the compensation electrode should be equal with the value of the leakage current flowing through the (+) ground electrode by using the square waveform. Throughout the experiment, the degree of corrosion on the compensation electrode is analyzed by the frequency of the compensation electrode for a certain time. In the experiment, the frequencies of the square waveform are considered for 0.1, 1, 10, 20, 50, 100 Hz, and 1 kHz. Through experiments and analysis, the optimal frequency for reducing the electrolytic damage of the (+) electrode and compensation electrode in an LVDC grounding environment is determined.

• International Journal of Contents
• /
• 제6권2호
• /
• pp.6-9
• /
• 2010

Using symplectic relation and reaction concept, we propose a planar near-field antenna measurement method. A generalized probe compensation equation is deduced to obtain the probe correction formulation. To verify our approach, a reflector antenna with $1{\times}2$ horn array is fabricated and measured in the near-field measurement facility. The near-field measurement results are compared with the physical optics (PO) simulation. The results of measurement and simulation agree very well near to the mainbeam.

• The Journal of Korean Physical Therapy
• /
• 제11권1호
• /
• pp.63-70
• /
• 1999

This study was for mathematical method of calculating the joint reaction force during on single - leg stance on a normal and hemiplegic patients. It is important to compare the distance of the line of gravity from the hip joint on hemiplegic patients with this on normal in this study. In earlier studies, there is no include the concept about biomechanical analysis on the shin of line of gravity of hemiplegic patients. Though this concept, we found the compensation make the line of gravity closer to the supporting hip joint and the trunk was toward the side of paralysis. The result of the Joint reaction force on hemiplegic patients is found to be approximately $31.33\%$ in the unaffected side by biomechanical analysis.

• 항공우주시스템공학회지
• /
• 제10권1호
• /
• pp.86-94
• /
• 2016

In this paper, position control of focal plane compensation device using piezoelectric actuator is conducted. The forcal plane compensation device installed on earth observation satellite camera compensates micro-vibration from reaction wheels. In this study, four experimental models of the open-loop compensation device are derived using MATLAB system identification toolbox in the input range of 0~50Hz. Subsequently, the PID controller for each model is designed and the performance test of each controller is conducted through MATLAB/Simulink. According to frequency response analysis of the closed-loop compensation device system, the PID controller designed for 38~50Hz input range has enough tracking performance for the whole 0~50Hz input range. The maximum output error is about $1{\mu}m$ for the input range. The simulation results has been verified by the experimental method.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
• /
• 한국우주과학회 2005년도 한국우주과학회보 제14권1호
• /
• pp.138-142
• /
• 2005

위성자세제어용 구동기 인 반작용 휠은 축 방향 토크뿐만 아니 라 횡 축 방향 외 란 토크와 힘을 발생시켜 위성의 정밀 지향 안정성에 영향을 미치게 된다. 이를 위해서는 반작용 휠 구동시의 발생 외란을 정밀하게 측정할 필요가 있다. 그러나 반작용 휠의 구동은 측정테이블의 진동을 야기 시키고 테이블의 공진 주파수 영역에서 큰 측정 오차를 유발한다. 본 논문은 이러한 진동오차들을 줄이기 위하여 주파수 보정법에 의한 사후처리 과정을 제시하고, 이 보정법으로 얻어진 데이터들로부터 외란 파라미터를 결정함으로써 구동기 외란의 보다 정밀한 측정을 가능케 하기 위함이다. 이 보정법을 적용함으로써 구동기 외란 측정 주파수범위를 넓힐 수 있다.

• 대한기계학회논문집A
• /
• 제21권2호
• /
• pp.252-260
• /
• 1997

In this paper, a friction compensation method using a disturbance observer is proposed for an impedance control of pneumatic manipulator. It is assumed that the generated torque by a pneumatic actuator can be estimated based on the pressure signals and the discharge volume. In order to improve the dynamic characteristics of the pneumatic actuator driven by meter out method, we construct the inner torque control system by feeding back the generated torque. In order to reduce the influence of disturbances comprising friction torque and parameter variations of plant, the impedance control system is constructed with a disturbance observer which estimates the disturbances based on the generated torque of pneumatic actuator, the angular velocity and the reaction torque. From some experiments, it is confirmed that the proposed control system is effective to improve the robustness for the friction torque in the impedance control of a pneumatic manipulator.