• 전기의세계
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• v.37 no.4
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• pp.58-70
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• 1988

이하에서는 자기부상철도의 기본적인 동작원리와 특징, 개발 및 실용의 현상, 고속 시스템의 실용화의 전망, 종래의 철차륜, 철레일 방식의 철도와 비교했을 경우의 특징등에 대해서 설명한다.

• 전기의세계
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• v.39 no.5
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• pp.68-75
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• 1990

급속한 경제발전과 이에 대응한 교통인구의 증가로 운송시스템의 속도 경쟁은 날로 심화되고 있다. 그러나, 기존의 차륜구동 시스템은 본질적으로 궤도와 차륜의 마찰에 의하여 추진력을 얻기 때문에 평균 최대속도 250Km/h(상한 최대속도 350Km/h)수준이며 소음, 진동 등의 많은 문제점이 있다. 이러한 단점을 극복하기 위하여 선진 외국에서는 부상식 열차의 개발에 관심을 표명하여 1960년대 후반부터 열차와 공기부상식 열차에 대한 연구를 병행하였다. 1970년대 중반까지 프랑스, 영국, 미국 등에서 개발이 진행된 공기 부상식 열차는 고속 주행 및 환경 문제 등에 문제점이 많아 실용화에는 이루지 못하고 신교통 시스템에 부분적으로 적용되고 있는 실정이다. 그러나 자기부상 열차는 Power Electronics 및 자기관련 기술의 급속한 발전에 힘입어 현재 실용화 단계에 이르고 있다. 특히 자기부상(Magnetic Levitation : Maglev) 시스템은 레일과의 마찰력에 의해 추진하는 방식이 아니기 때문에 본질적으로 고속성, 무공해, 안정성, 신뢰성, 경제성 그리고 승차감이 뛰어나다. Maglev는 레일 표면에서 자력을 이용해서 약 1.0cm 또는 10cm 가량 부상한 상태에서 주행하기 때문에 외부와의 물리적인 접촉이 필요 없어 마찰에 의한 소음, 공해, 마모 등이 없는 대단히 이상적인 미래의 운송 수단으로 각광을 받고 있다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.11
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• pp.1353-1356
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• 2009

As a method obtaining linear thrust force for the magnet wheel producing a strong traction torque, the concept of magnetic shield is suggested and compared with the existing approaches. Specially, as the magnet wheel, in which the permanent magnets rotate mechanically instead of ac driving to make traveling field, is physically similar with the rotary induction motor, there is a periodical force ripple in tangential direction as well as normal direction. But, the force ripple can be suppressed from a shape change of the shield plate. Namely, the change brings out a change of entry and exit effect of the circumferential field for the magnet wheel. The feasibility of the shield concept is verified from simulation and experiment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.777-778
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• 2011

본 논문에서는 높은 신뢰성과 긴 수명을 특징으로 하는 저가형 센서로 마그네틱 픽업코일 방식의 자기유도작용을 이용한 수동형 차륜 속도센서를 제작하여 그 특성을 분석하였다. 제작된 수동형 차륜 속도센서는 직접적인 유도 기전력을 감지하여 유도하는 Pole piece, 영구자석과 Bobbin역할을 하는 내피와 코일로 구성된 센서부, 세서를 보호하고 외부 노이즈를 제거하는 외피부, 그리고 센서를 보강 및 고정하기 위한 플랜지부로 구성된다. 제작된 센서를 기성품과 특성을 비교, 분석하였다.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.2
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• pp.171-176
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• 2013

In this research a Self-Standable mobile Robot with standing arms based on an Wheeled Inverted Pendulum is developed. Almost existing mobile robots have wide planar shape that is statistically stable and it is sometimes hard for them to run or steer on a narrow road. A Wheeled Inverted Pendulum based mobile robot has vertical shape that is upright-running and easily steering on a narrow road. It, however, requires actively balancing control and never restores the shape once it falls down. This research develops a Self-Standable mobile robot which equips standing arms and is able to change its chassis' posture freely from planar to vertical shape or vice versa.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.579-584
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• 2008

A novel nondestructive testing (NDT) system, which is able to detect a crack with high speed and high spatial resolution, is urgently required for inspecting small cracks on express train wheels. This paper proposes an improved signal processing circuits, which uses the multiple amplifying circuits and the crack indicating pulse output system of the previous scan-type magnetic camera. Hall sensors are arrayed linearly, and the wheel is rotated with static speed in the vertical direction to sensor array direction. Each Hall voltages are amplified, converted and immediately operated by using, amplifying circuits, analog-to-digital converters and $\mu$-processor, respectively. The operated results, ${\partial}V_H/{\partial}t$, are compared with a standard value, which indicates a crack existence. If the ${\partial}V_H/{\partial}t$ is larger than standard value, the pulse signal is output, and indicates the existence of crack. The effectiveness of the novel method was verified by examine using cracks on the wheel specimen model.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.9
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• pp.72-80
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• 2009

When the magnet wheel rotates over a conducting plate, it generates the traction torque as well as the repulsive force on the conducting plate. Partially-cut traction torque results in the linear force into the tangential direction. To cut the traction torque, the concept of magnetic shield is introduced. The direction change of the linear force is realized varying the shielded area of magnetic field. That is, the tangential direction of non-shielded open area becomes the direction of the linear thrust force. Specially a shape of permanent magnets composing the magnet wheel leads to various pattern of magnetic forces. So, to enlarge the resulting force density and compensate its servo property a few simulations are performed under various conditions such as repeated pattern, pole number, radial width of permanent magnets, including shape of open area. The theoretical model of the magnet wheel is derived using air-gap field analysis of linear induction motor, compared with test result and the sensitivity analysis for its parameter change is performed using common tool; MAXWELL. Using two-axial wheel set-up, the tracking motion is tested for a copper plate with its normal motion constrained and its result is given. In conclusion, it is estimated that the magnet wheel using partial shield can be applied to a noncontact conveyance of the conducting plate.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.11
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• pp.943-950
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• 2008

A novel nondestructive testing (NDT) system, which is able to detect a crack with high speed and high spatial resolution, is urgently required for inspecting small cracks on express train wheels. This paper proposes a high speed scan type magnetic camera, which uses the multiple amplifying circuits and the crack indicating pulse output system. The linearly integrated Hall sensors are arrayed in parallel, and the Hall voltages from each sensor in the scanning direction are obtained and amplified. High-speed NDT can be achieved by using the exclusive analog-digital converter and micro-processor because the ${\partial}\;V_H/\;{\partial}$ x value, which provides the most important crack information, can be obtained by buffering and calculating. The effectiveness of the novel method was verified by examine using cracks on the wheel specimen model.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.7
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• pp.109-116
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• 2010

The magnet wheel which generates on its interfacing conductive part a repulsive force and a traction torque by rotation of permanent magnets is used to manipulate the conductive plate without mechanical contact. Here, the air-gap magnetic field of the magnet wheel is shielded partially to convert the traction torque into a linear thrust force. Although a magnitude of the thrust force is constant under the fixed open region, we can change the direction of force by varying a position of the shield sheet. So, the spatial position of conductive plate is controlled by not the force magnitude from each magnet wheel but the open position of shield sheet. This paper discusses non-contact conveyance system of the conductive plate using electromagnetic forces from multiple magnet wheels.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.6
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• pp.1010-1017
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• 2013

Two-axial electrodynamic forces generated on a conductive plate by a partially shielded magnet wheel are strongly coupled through the rotational speed of the wheel. To control the spatial position of the plate using magnet wheels, the forces should be handled independently. Thus, three methods are proposed in this paper. First, considering that a relative ratio between two forces is independent of the length of the air-gap from the top of the wheel, it is possible to indirectly control the in-plane position of the plate using only the normal forces. In doing so, the control inputs for in-plane motion are converted into the target positions for out-of-plane motion. Second, the tangential direction of the open area of the shield plate and the rotational speed of the wheel become the new control variables. Third, the absolute magnitude of the open area is varied, instead of rotating the open area. The forces are determined simply by using a linear controller, and the relative ratio between the forces creates a unique wheel speed. The above methods were verified experimentally.