• International journal of advanced smart convergence
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• 제13권3호
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• pp.101-108
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• 2024

This paper addresses the implementation of an on-device AI-based metal detection system using a Magneto-Impedance Sensor. Performing calculations on the AI device itself is essential, especially for unmanned aerial vehicles such as drones, where communication capabilities may be limited. Consequently, a system capable of analyzing data directly on the device is required. We propose a lightweight gated recurrent unit (GRU) model that can be operated on a drone. Additionally, we have implemented a real-time detection system on a CPU embedded system. The signals obtained from the Magneto-Impedance Sensor are processed in real-time by a Raspberry Pi 4 Model B. During the experiment, the drone flew freely at an altitude ranging from 1 to 10 meters in an open area where metal objects were placed. A total of 20,000,000 sequences of experimental data were acquired, with the data split into training, validation, and test sets in an 8:1:1 ratio. The results of the experiment demonstrated an accuracy of 94.5% and an inference time of 9.8 milliseconds. This study indicates that the proposed system is potentially applicable to unmanned metal detection drones.

• 한국전자통신학회논문지
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• 제12권6호
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• pp.1057-1064
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• 2017

거대자기임피던스 효과를 이용한 자기센서를 사용하여 자화된 금속이물질을 감지할 수 있는 고감도 금속이물질 감지 센서를 구현하였다. 스트립 형태의 센서는 지자기의 영향으로 스트립의 축방향이 놓인 위치에 따라 초기 직류전압은 다르게 나타났지만 접지점에 연결된 스트립에서 멀어질수록 외부 자계에 대한 출력전압이 증가하며 스트립의 축 방향에는 무관함을 나타내었다. 제안하는 자기센서는 고감도 실현을 위하여 능동잡음필터를 적용하여 기저잡음의 반 이상을 제거할 수 있었고 설치된 주변 환경에서 발생하는 전자기 잡음 및 지자기로 부터의 영향을 받지 않고 자화된 금속 이물질을 검출할 수 있음을 보여주었다. 자화된 철구의 경우 5mm 이격거리에서 지름 0.8mm 까지 감지가 가능함을 실험적으로 보여주었다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1997년도 한국재료학회 춘계학술발표회
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• pp.38-38
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• 1997

In the paper, we investigate the magneto-impedance(MI) effect of the Fe-Co-B Amorphous magnetic film, the amorphous magnetic film having near zero magnetostostriction is fabricated by using the sputtering methode, and then annealed in magnetic field. When the external magnetic field is directly applied to the fabricated film, the voltage amplitude between both side of the magnetic film varies about 22% at 10[MHz] and the impedance varies about 21% at 10[Oe]. Thus, we find that the fabricated magnetic film has the characteristics of high-quality sensor element.

• Journal of Magnetics
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• 제9권2호
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• pp.47-51
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• 2004

Giant magneto-impedance (GMI) effect in zero-magnetostrictive Co-based amorphous ribbons samples in their as-quenched and stress-released states as well as with intentionally induced magnetic anisotropy were investigated. Magnetic and impedance properties of the samples exhibiting different anisotropy were compared and the optimum operation conditions for the studied samples from the view-point of their utilization as a sensor element have been determined. A design of a model of magnetic field sensor and characteristics of the constructed prototype are presented.

• 한국전기전자재료학회논문지
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• 제17권1호
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• pp.52-58
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• 2004

Magneto-Impedance(MI) sensor is a highly sensitive sensor, which was able to detect a weak geomagnetic field. It also has a merit to be able to build in the low power system. In this study, their magnetic permeability and anisotropy field(H$\sub$k/) as a function of some different thickness of sputtered amorphous CoZrNb films with zero-magnetostriction and soft magnetic property are investigated. In order to make a uniaxial anisotropy, film was subjected to the post annealing in a static magnetic field with 1KOe intensity at 250, 300, and 320$^{\circ}C$ respectively for 2 hours. Magnetic properties of films are measured by using a M-H loop tracer. Magnetic permeability of a film is measured over the frequency range from 1 ㎒ to 750㎒. By thickening a CoZrNb film relatively, magnetic permeability and impedance are examine to design the. MI sensor which drives at 50㎒, and thereof fabricated the MI sensor which drives at the 50㎒.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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• pp.132-135
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• 2002

MI(Magneto-Impedance) sensor which is made by thin films has significantly high detecting sensitivity in weak magnetic field. It also has a merit to be able to build in the low power system. Its structure is simple, which makes it easier to prepare a miniature. In this study, its magnetic permeability and anisotropy field($H_{k}$) as a function of a thickness of sputtered amorphous CoZrNb films with zero-magnetostriction and soft magnetic property are investigated. In order to make a uniaxial anisotropy, film was subjected to the post annealing in a static magnetic field with 1KOe intensity at 250, 300, and $320^{\circ}C$ respectively for 2 hours. Magnetic properties of film are measured by using a MH loop tracer. Its magnetic permeability of a film is measured over the frequency range 1 MHz to 750MHz. And, it was examined on the permeability and impedance to design the MI sensor which acts at 50MHz by thickening a CoZrNb film relatively, and fabricated the MI sensor which acts at the 50MHz.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.778-781
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• 2002

MI(Magneto-Impedance) sensor which is made by thin films has significantly high detecting sensitivity in weak magnetic field. It also has a merit to be able to build in the low power system. Its structure is simple, which makes it easier to prepare a miniature. In this study, its magnetic permeability and anisotropy field$(H_k)$ as a function of a thickness of sputtered amorphous CoZrNb films with zero-magnetostriction and excellent soft magnetic property are investigated. In order to make a uniaxial anisotropy, film was subjected to the post annealing in a static magnetic field with 1KOe intensity at 250, 300, and $320^{\circ}C}$ respectively for 2 hours. Anisotropy field$(H_k)$ of film is measured by using a MH loop tracer. Its magnetic permeability of a film is measured over the frequency range from 1 MHz to 750MHz. It has shown that the magnetic permeability of amorphous CoZrNb film is decreased due to the skin effect with increasing a thickness of the CoZrNb film, and hence its driving frequency is lowered. And, it was examined on the permeability and impedance to fabricate the MI sensor which acts at a low frequency by thickening a CoZrNb film relatively.

• 센서학회지
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• 제16권5호
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• pp.389-393
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• 2007

Soft ferromagnetic materials are very useful for many sensors using magnetic materials demanding high permeability, low coercivity and low hysteresis loss. Among them, FeCoSiBNi amorphous magnetic films show a good impedance change (about 5.01 %/Oe, at 10 MHz) by the exterinal magnetic field in this experiment. The magnetic films are produced by melt-spun method, one of the rapid solidification process. Ribbon shape wires were made from the films, and let them annealed in DC magnetic field to increase the maximum Giant Magneto Impedance ratio. Field annealing decreases the stress and changes the effective anisotropy. Thus, we can find that the impedance change (200.47 %) is improved and the fabricated magnetic wire has characteristics of good sensor element.

• Journal of Magnetics
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• 제14권1호
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• pp.42-46
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• 2009

The measurement of external magnetic field orientation using Giant Magneto Impedance (GMI) sensors has been performed. A soft magnetic alloy of $Co_{30}Fe_{34}Ni_{36}$ was electroplated on a Si wafer with a CoFeNi seed layer. V-shaped microwire patterns were formed using a conventional photolithography process. An external magnetic field was generated by a rectangular AlNiCo permanent magnet. The reference direction was defined as the external magnetic field direction oriented in the middle of 2 GMI devices. As the orientation of the magnetic field deviated from the reference direction, variation in the field component along each device introduced voltage changes. It was found that, by taking the voltage difference between the left and right arms of the Vshaped device, the nonlinearity of each device could be significantly reduced. The fabricated angle sensor had a linear range of approximately $70^{\circ}$ and an overall sensitivity of approximately 10 mV.

• 센서학회지
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• 제12권5호
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• pp.205-210
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• 2003

고감도의 자기임피던스센서를 구현하기 위해서 아몰퍼스리본을 리소그래피와 습식에칭을 통하여 미안더패턴으로 미소가공하고 임피던스의 외부자계의존성을 조사하였다. 센서의 임피던스는 외부자계 약 13 Oe 부근에서 가장 큰 값을 나타내었고, 약 170%의 변화율을 나타내었다. 선형성과 감도가 확보될 수 있는 외부자계영역(6 Oe부근)에서의 임피던스의 변화를 평가해 보면 약 36%의 단위자계당 임피던스 변화율을 확보할 수 있음을 알 수 있다. 제작한 센서패턴과 센서를 구동하기 위해서 제작된 구동회로를 이용하여 약 $10^{-3}$ Oe의 미약자계를 측정할 수 있다는 것을 알 수 있었다.