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다양한 PCB의 전원 분배 망에서의 PLL의 전자기 내성 검증
황원준(Won-Jun Hwang),위재경(Jae-Kyung Wee) 대한전자공학회 2015 전자공학회논문지 Vol.52 No.5
전자장치의 복잡도 증가와 전원 전압 감소 추세에 따라, 내부 또는 외부에서 발생되는 노이즈에 대한 칩 또는 모듈의 전자기 내성 평가는 필수적이다. 칩 레벨 EMS 표준 시험방법으로 IEC 62132-4의 Direct Power Injection(DPI) 방법이 있지만, 실제 칩 내성은 모듈 상 보드 PDN 구조에 영향 받는다. 이 논문에서는 PLL의 내성을 평가하고 보드의 PDN 구조에 따른 잡음전달 특성을 비교하였다. 여러 PDN을 만들기 위해 다양한 값의 커패시터들과 LDO 사용 유무 조건이 적용되었다. IC의 전자기 요구사항과 IC 및 보드로 구성된 모듈의 전자기 요구사항 간 불일치를 평가하기 위해, PDN들에 따른 노이즈 전달 특성을 분석하는 것은 강건한 EM 특성을 갖도록 설계하는데 중요한 정보를 줄 수 있음을 보였다. DPI 측정 결과는 LDO 사용에 따라 PLL 저주파 영역의 내성이 크게 개선되었음을 보여주며, DPI에 따른 PLL의 주파수 변화를 TEM cell 스펙트럼 측정으로도 확인 할 수 있었다. As the complexity of an electronic device and the reduction of its operating voltage is progressing, susceptibility test of the chip and module for internal or external noises is essential. Although the immunity compliance of the chip was served with IEC 62132-4 Direct Power Injection method as an industry standard, in fact, EM immunity of the chip is influenced by their Power Domain Network (PDN). This paper evaluates the EM noise tolerance of a PLL and compares their noise transfer characteristics to the PLL on various PCB boards. To make differences of the PDNs of PCBs, various PCBs with or without LDO and with several types of capacitors are tested. For evaluation of discrepancies between EM characteristics of an IC only and the IC on real boards, the analysis of the noise transfer characteristics according to the PDNs shows that it gives important information for the design having robust EM characteristics. DPI measurement results show that greatly improved immunity of the PLL in the low-frequency region according to using the LDO and a frequency change of the PLL according to the DPI could also check with TEM cell measurement spectrum.
Won-Jun hwang(황원준),In-Man Park(박인만),Un-Wook Kang(강언욱),Sung-Hyun Han(한성현) 한국산업융합학회 2014 한국산업융합학회 논문집 Vol.17 No.3
We propose a new technique for autonomous navigation and travelling of mobile robot based on ultrasonic sensors through the narrow labyrinth that leave only distance of a few centimeters on each side between the guides and the robot. In our current implementation the ultrasonic sensor system fires at a rate of 100 ms, that is, each of the 8 sensors fires once during each 100 ms interval. This is a very good firing rate, implemented here for optimal performance. This paper presents an extensively tested and verified solution to the problem of obstacle avoidance. Our solution is based on the optimal placement of ultrasonic sensors at strategic locations around the robot. Both the sensor location and the associated navigation algorithm are defined in such a way that only the accurate radial sonar data is used for accurate travelling.
안정된 로봇걸음걸이를 위한 견실한 제어알고리즘 개발에 관한 연구
황원준(Won-Jun Hwang),윤대식(Dae-Sik Yoon),구영목(Young-Mok Koo) 한국산업융합학회 2015 한국산업융합학회 논문집 Vol.18 No.4
This study presents new scheme for various walking pattern of biped robot under the limitted enviroments. We show that the neural network is significantly more attractive intelligent controller design than previous traditional forms of control systems. A multilayer backpropagation neural network identification is simulated to obtain a learning control solution of biped robot. Once the neural network has learned, the other neural network control is designed for various trajectory tracking control with same learning-base. The main advantage of our scheme is that we do not require any knowledge about the system dynamic and nonlinear characteristic, and can therefore treat the robot as a black box. It is also shown that the neural network is a powerful control theory for various trajectory tracking control of biped robot with same learning-vase. That is, we do net change the control parameter for various trajectory tracking control. Simulation and experimental result show that the neural network is practically feasible and realizable for iterative learning control of biped robot.
황원준(Won Jun Hwang),심병균(Byoung kyun Shim),조창제(Chang Jae Cho),한성현(Sung Hyun Han) 한국생산제조학회 2011 한국생산제조시스템학회 학술발표대회 논문집 Vol.2011 No.4
This paper is the development of industrial robot hand's and the design methods of industrial robot hand that can mimic human fingers motion. In order to overcome problems incurred during the reduction of the mobility, this study focuses on analyzing human hand structure and finger movements from an anatomical point of view. As a result, distinctive features that improve the discovered stability in constraints for range of motion in the fingers is reflected in this design concept. A 4-bar Linkage is used in robot finger structure. Lastly, there were experiments to inspect the developed robot hands performance. The developed robot hand has many potential applications and can be in many different fields.
하이브리드 시뮬레이션을 이용한 PC벽체 수직접합부 이력댐퍼의 성능평가
황원준(Hwang, Won Jun),이종억(Lee, Jong Eok),김승직(Kim, Sung Jig),장준호(Chang, Chun Ho) 한국콘크리트학회 2021 한국콘크리트학회 학술대회 논문집 Vol.33 No.2
본 논문에서는 하이브리드 시뮬레이션을 이용한 PC벽체 수직접합부의 이력댐퍼에 대한 성능을 평가하였다. 하이브리드 시뮬레이션은 실험모듈과 해석모듈이 합쳐진 기법으로서, PC벽체는 OpenSees를활용 하여 모델링 하고, 이력댐퍼는 해석모델의 변위응답을 활용하여 실험을 수행하였다. 또한, 해석모듈에서 도출되는 변위응답은 높은 정밀도로 액추에이터에서 가력되었다. 따라서, 수직접합부가 적용된 PC벽체의 전체 거동을 평가하기 위해서는 하이브리드 시뮬레이션이 가장 경제적이고 효과적이라고 판단된다. This paper was evaluated the performance of vertical joint composed of the hysteretic steel damper between precast concrete (PC) walls by conducting the hybrid simulation. The hybrid simulation is an experimental technique that combines an experimental module and an analysis module. In addition, PC walls were modeled using OpenSees of non-linear analysis program, and then the hysteretic steel damper was tested using the deformation in displacement response of an analysis module. Also, the displacement derived from the response of an analysis module was applied to specimens with high accuracy by the actuator. Therefore, it is concluded that the hybrid simulation is the most economical and effective to experimentally evaluate the overall behavior of the PC walls with the vertical joint.
황원준(Won-Jun Hwang),이우송(Woo-Song Lee) 한국산업융합학회 2015 한국산업융합학회 논문집 Vol.18 No.2
This research propose with image-based visual a new approach to design a feedback control of mobile robot. because mobile robot must be recharged periodically , it is necessary to detect and move to docking station. Generally, laser scanner is used for detect of position of docking station. CCD Camera is also used for this purpose. In case of using camera, the position-based visual servoing method is widely used. But position-based visual servoing method requires the accurate calibration and it is hard and complex work. Another method using cameras is inmage-based visual feedback. Recently, image based visual feedback is widely used for robotic application. But it has a problem that cannot have linear trajectory in the 3-dimensional space. Because of this weak point, image-based visual servoing has a limit for real application. in case of 2-dimensional movement on the plane, it has also similar problem. In order to solve this problem, we point out the main reason of the problem of the resolved rate control method that has been generally used in the image-based visual servoing and we propose an image-based visual feedback method that can reduce the curved trajectory of mobile robot in th cartesian space.
철근콘크리트 기둥의 반복거동에 대한 이력모델 매개변수 예측
황원준 ( Hwang Won Jun ),김승직 ( Kim Sung Jig ) 한국구조물진단유지관리공학회 2021 한국구조물진단유지관리공학회 학술발표대회 논문집 Vol.25 No.2
본 연구는 철근콘크리트 기둥의 물리적 변수를 활용하여 반복거동에 대한 이력모델을 예측하는 것을 목적으로 한다. 수집한 기둥실험체의 데이터를 활용해 이력거동 매개변수를 도출하였다. 도출한 매개변수와 물리적 변수의 상관관계를 분석하여 이력모델의 매개변수 예측식을 제안하였다. 제안된 예측식을 활용한 해석모델과 실험결과를 비교하여 검증을 수행한 결과, 전반적으로 실험체와 유사한 거동을 나타내었다. 하지만 강도·강성 저감 현상이 제대로 반영되지 않아 과대평가 되는 경향이 나타났다. 이는 회귀분석을 위한 모집단 선정 시 파괴모드를 구분하여 고려하지 않았기 때문으로 판단된다.