Position-based compensation of electromagnetic fields interference for electromagnetic locomotive microrobot

Choi, Jongho,Choi, Hyunchul,Jeong, Semi,Park, Bang Ju,Ko, Seong Young,Park, Jong-Oh,Park, Sukho SAGE Publications 2013 Proceedings of the Institution of Mechanical Engin Vol.227 No.9

<P>Recently, the locomotion of a microrobot wirelessly actuated by electromagnetic actuation systems has been studied in many ways. Because of the inherent characteristics of an electromagnetic field, however, the magnetic field of each coil in the electromagnetic actuation system induces magnetic field interferences, which can distort the desired electromagnetic field, preventing the microrobot from following the desired path. In this article, we used two pairs of Helmholtz coils and two pairs of Maxwell coils in a two-dimensional electromagnetic actuation system. Generally, the two pairs of Helmholtz coils generate the torque for the rotation of the microrobot and the two pairs of Maxwell coils generate the propulsion force of the microrobot. Both pairs of Helmholtz and Maxwell coils have to work to simultaneously align and propel the microrobot in a desired direction. In this situation, however, the electromagnetic fields produced by the Helmholtz coils can interfere with those produced by the Maxwell coils. This interference is closely dependent on the position of the microrobot in the region of interest inside the electromagnetic coils system. This means that the alignment direction and propulsion force of the microrobot can be distorted according to the position of the microrobot. Therefore, we propose a compensation algorithm for the electromagnetic field interference using the position information of the microrobot to correct the magnetic field interferences. First, the interference of an electromagnetic field obeying the Biot–Savart law is analyzed by numerical analysis. Second, a position-based compensation algorithm for the locomotion of a microrobot is proposed. Various locomotion tests of a microrobot verified that the proposed compensation algorithm could reduce the normalized average tracking error from 5.25% to 1.92%.</P>

전자파환경에서 EED에 유기되는 전류에 관한 연구

김응조 한국군사과학기술학회 2002 한국군사과학기술학회지 Vol.5 No.2

Electro Explosive Devices can be susceptible to electromagnetic interference. When these components are exposed to external electromagnetic fields, it may cause to induce sufficient current to generate enough heat for an inadvertent detonation. It is almost impossible to monitor the event of firing throughout the electromagnetic environment test. The survivability of EED for hazards of electromagnetic radiation is investigated. A fiber optic sensor is installed near the bridge wire after removing explosive material in order to measure the induced current on the bridge wire. The length of lead-wire of the EED fabricated is around 15 cm.

전기도금법으로 제조된 탄소나노튜브/구리 복합체의 전자기파 차폐 연구

이승혁,신명규,송현준,정영진 한국섬유공학회 2020 한국섬유공학회지 Vol.57 No.4

With the development of wireless technology, it has become necessary to protect information technology devices from electromagnetic interference with electromagnetic- shielding materials. In this study, an electromagnetic-shielding material was prepared using a carbon nanotube (CNT) sheet electroplated with copper. The copper electroplating on the CNT sheet improved the electrical conductivity of the CNT sheet, which increased the overall shielding effectiveness (SE). The SE was evaluated using a vector network analyzer. The measured SE of the raw CNT sheet was 37.84 dB, and the SE of the composite sheet electroplated with copper increased to 83.9 dB, which was comparable to that of pure copper. Additionally, the composite sheet showed a high SE per unit thickness of 5412.72 dB/mm. Therefore, this study serves a reference for the improved development of thin light materials via copper electroplating on CNT sheets for electromagnetic-interference shielding.

적외선식 불꽃감지기의 전자파 적합성 개선

송현선(Hyun-Seon Song),이의용(Yeu-Yong Lee) 한국조명·전기설비학회 2014 조명·전기설비학회논문지 Vol.28 No.1

The infrared, flame detector uses to detect fire situation from the characteristics of fire sources radiant energy. But it is able to malfunction on account of susceptible to interference of various surrounding waves. This paper is designed 6 independent PCB- boards to minimize the closed loops of siginal circuit. Also considering the interaction of electric and magnetic fields , this paper is designed protecting circuit of current and voltage output to reduced electromagnetic interference. And this paper is improving electromagnetic susceptibility by ferrite bid, capacitor filter and grounding circuits.

제강Slag 충진 폐플라스틱/복합 전도성 filler 복합재료의 전자파 차폐 효과

강영구,송종혁 한국안전학회 2004 한국안전학회지 Vol.19 No.4

Electromagnetic interference(EMI) shielding characteristics of composite filled with Cu flake and carbon brush powder as hybrid conductive filler and EAF slag have been studied. The coaxial transmission line method of ASTM D4935-99 was used to measure the EMI Shielding effectiveness of composites as formulation in frequency rage 100~1,000MHz. The SE also increases with the increase in filler loading. The hybrid filler filled composites show higher SE compared to that of only Cu flake. The correlation between SE and conductivity of the various composites is also discussed. The results indicate that the composites having higher filler loading(≥40wt.%) can be used for the purpose of safety materials to protect hazardous electromagnetic interference.

VERIFICATION OF ELECTROMAGNETIC EFFECTS FROM WIRELESS DEVICES IN OPERATING NUCLEAR POWER PLANTS

예송해,유준 한국원자력학회 2015 Nuclear Engineering and Technology Vol.47 No.6

Wireless communication technologies, especially smartphones, have become increasinglycommon. Wireless technology is widely used in general industry and this trend is alsoexpected to grow with the development of wireless technology. However, wireless technologyis not currently applied in any domestic operating nuclear power plants (NPPs)because of the highest priority of the safety policy. Wireless technology is required inoperating NPPs, however, in order to improve the emergency responses and work efficiencyof the operators and maintenance personnel during its operation. The wired telephonenetwork in domestic NPPs can be simply connected to a wireless local area networkto use wireless devices. This design change can improve the ability of the operators andpersonnel to respond to an emergency situation by using important equipment for a safeshutdown. IEEE 802.11 smartphones (Wi-Fi standard), Internet Protocol (IP) phones, personaldigital assistant (PDA) for field work, notebooks used with web cameras, and remotesite monitoring tablet PCs for on-site testing may be considered as wireless devices thatcan be used in domestic operating NPPs. Despite its advantages, wireless technology hasonly been used during the overhaul period in Korean NPPs due to the electromagneticinfluence of sensitive equipment and cyber security problems. This paper presents theelectromagnetic verification results from major sensitive equipment after using wirelessdevices in domestic operating NPPs. It also provides a solution for electromagnetic interference/radio frequency interference (EMI/RFI) from portable and fixed wireless deviceswith a Wi-Fi communication environment within domestic NPPs.

EMI Noise Source Reduction of Single-Ended Isolated Converters Using Secondary Resonance Technique

Zhang-yong Chen,Yong Chen,Qiang Chen,Wei Jiang,Rongqiang Zhong 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.2

Aiming at the problems of large dv/dt and di/dt in traditional single-ended converters and high electromagnetic interference (EMI) noise levels, a single-ended isolated converter using the secondary resonance technique is proposed in this paper. In the proposed converter, the voltage stress of the main power switch can be reduced and the voltage across the output diode is clamped to the output voltage when compared to the conventional flyback converter. In addition, the peak current stress through the main power switch can be decreased and zero current switching (ZCS) of the output diode can be achieved through the resonance technique. Moreover, the EMI noise coupling path and an equivalent model of the proposed converter topology are presented through the operational principle of the proposed converter. Analysis results indicate that the common mode (CM) EMI noise and the differential mode (DM) EMI noise of such a converter are deduced since the frequency spectra of the equivalent controlled voltage sources and controlled current source are decreased when compared with the traditional flyback converter. Furthermore, appropriate parameter selection of the resonant circuit network can increase the equivalent impedance in the EMI coupling path in the low frequency range, which further reduces the common mode interference. Finally, a simulation model and a 60W experimental prototype of the proposed converter are built and tested. Experimental results verify the theoretical analysis.

항공용 모터 조립체의 전자기 간섭 감쇠 방안

김지흥 ( Jee-heung Kim ),유홍균 ( Hong-kyun Ryu ),박범준 ( Beom-jun Park ),박영주 ( Young-ju Park ) 한국항행학회 2018 韓國航行學會論文誌 Vol.22 No.5

본 연구에서는 개발된 모터 조립체의 누설 잡음신호 감쇠 방안을 시험을 통해 제안한다. 개발된 장치는 항공기 외부에 장착되어 안테나를 회전시키기 위한 장치로서 전자기 간섭 측면에서 MIL-STD-461F의 RE102 요구규격을 충족해야한다. RE102 시험결과를 통해 장치의 누설 잡음신호가 전원 및 제어 케이블을 통한 외부 유입과 모터 회전에 의해 발생됨을 확인하였다. 그리고 회전을 위해 내·외부의 물리적 차폐가 어려운 부분에서 잡음신호가 누설됨을 확인하였다. 누설 잡음신호에 대한 감쇠를 위해 장치 동작을 고려한 전기적 접지 보강, 전기적 차폐 구조를 적용하여 시험을 수행했고 규격 충족 여부를 확인하였다. 최종적으로 잡음누설 경로에 맞물리는 형태를 갖는 원형 주름 초크 구조와 전도성 그리스를 함께 적용하여 요구규격을 충족함을 확인하였다. In this study, we propose a method of suppressing the leakage noise signal of motor assembly through the test. The motor assembly is mounted on outside of the aircraft to rotate an antenna and must satisfy RE102 requirement on MIL-STD-461F in terms of electromagnetic interference. It is confirmed by RE102 test result hat the leakage noise signal of the equipment occurs due to external influx through the power and control cable and rotation of the motor. And it is ascertained that the part where internal/external physical shielding is difficult to rotate is the leakage path. To reduce the leakage noise signal, the electrical ground reinforcement and the electric shielding structure considering the operation of the equipment is applied and it is verified that the requirement is satisfied. Finally, we verified that required specification are met by applying circular corrugated choke with interlocking shapes and conductive grease to the noise leakage path.

EMI Noise Source Reduction of Single-Ended Isolated Converters Using Secondary Resonance Technique

Chen, Zhangyong,Chen, Yong,Chen, Qiang,Jiang, Wei,Zhong, Rongqiang The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.2

Aiming at the problems of large dv/dt and di/dt in traditional single-ended converters and high electromagnetic interference (EMI) noise levels, a single-ended isolated converter using the secondary resonance technique is proposed in this paper. In the proposed converter, the voltage stress of the main power switch can be reduced and the voltage across the output diode is clamped to the output voltage when compared to the conventional flyback converter. In addition, the peak current stress through the main power switch can be decreased and zero current switching (ZCS) of the output diode can be achieved through the resonance technique. Moreover, the EMI noise coupling path and an equivalent model of the proposed converter topology are presented through the operational principle of the proposed converter. Analysis results indicate that the common mode (CM) EMI noise and the differential mode (DM) EMI noise of such a converter are deduced since the frequency spectra of the equivalent controlled voltage sources and controlled current source are decreased when compared with the traditional flyback converter. Furthermore, appropriate parameter selection of the resonant circuit network can increase the equivalent impedance in the EMI coupling path in the low frequency range, which further reduces the common mode interference. Finally, a simulation model and a 60W experimental prototype of the proposed converter are built and tested. Experimental results verify the theoretical analysis.

가공송전선 유도장해 특성을 고려한 최적 상배열 연구

강경두(Kyung-Doo Kang),김진규(Jin-Gyu Kim) 대한전기학회 2019 전기학회논문지 Vol.68 No.1

The domestic overhead transmission lines use a vertical configuration and reverse phase arrangement, but when there is a limitation in steel tower height because the transmission lines pass a height limit zone or special zone, an application of triangular arrangement is necessary, and a study on the optimal phase arrangement to minimize inductive interference for this is necessary. If conductor arrangement are changed, the action of electrostatic induction and electromagnetic induction becomes different from before changes, so the changed conductor arrangement should be reviewed in terms of inductive interference. So this paper presents an optimal phase arrangement to reduce inductive interference by calculating electrostatic induction and electromagnetic induction according to conductor arrangement.