2005 Fiscal Year Final Research Report Summary
Development of Visualization System for Low-Frequency Electromagnetic Noise Sources
| Project/Area Number |
16560361
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Measurement engineering
|
|---|
| Research Institution | Kanazawa University |
|---|
Principal Investigator |
YAGITANI Satoshi Kanazawa University, Graduate School of Natural Science and Technology, Associate Professor, 自然科学研究科, 助教授 (30251937)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
NAGANO Isamu Kanazawa University, Graduate School of Natural Science and Technology, Professor, 自然科学研究科, 教授 (50019775)
IMACHI Tomohiko Information Media Center of Kanazawa University, Research Associate, 総合メディア基盤センター, 助手 (60372489)
|
|---|
| Project Period (FY) |
2004 – 2005
|
| Keywords | Localization of noise sources / MUSIC algorithm / Low-frequency sources / Magnetic dipoles / Coherent sources / Wireless magnetic sensors / Source visualization / EMC / EMI |
|---|
| Research Abstract |
In order to reduce the undesired electromagnetic (EM) noise emissions from the electrical and electronic equipment under the actual operating conditions, it is important to identify the locations of the noise sources inside the equipment, by measuring the EM field distributions of the noise emissions externally. In this study we have applied the MUSIC algorithm to estimate and visualize the 3-d locations and orientations of the low-frequency (less than MHz) current sources, by measuring the magnetic field distributions around the sources with an array of magnetic vector sensors. The main results obtained are as follows :
1. We have extended the MUSIC algorithm to localize not only the point dipole sources, but also the line and loop current sources which have finite spatial extent.
2. The conventional MUSIC algorithm was unable to distinguish highly coherent multiple dipole sources. On the basis of the "spatio-temporal independent topography" model, we have applied the RAP (Recursively Applied and Projected)-MUSIC algorithm with a multiple dipole search, to identify and localize the coherent dipole sources.
3. Awireless and portable AC magnetic field sensor has been developed.
4. We have developed an experimental system to locate the low-frequency current loop (magnetic dipole) sources. The magnetic field wave forms acquired by a couple of AC magnetic sensors are sampled and digitized by a PC, and the current sources are localized by the MUSIC algorithm. We also "visualize" the estimated sources on a computer screen, by superimposing them directly on the "real" camera image of the sources.
5. The low-frequency noise sources existing in the actual electric and electronic equipment, such as an electric heater, an LCD TV, and a notebook PC, have been localized and visualized with the developed system.
|
