• Journal of the Korean Society for Precision Engineering
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• v.29 no.11
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• pp.1159-1163
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• 2012

In this paper, we would like to introduce two dimensional non-contact position sensor by using an electromagnetic induction based coil system and an algorithm to estimate the position of pointer. The sensor which will introduce in this paper is composed of a pointer including LC resonant circuit and a sensor board to detect the electromagnetic signal from the pointer. Because of the simplicity shape of the line antenna, low cost and free form curved shape of the sensor device is possible. In this research, we proposed a new two dimensional non-contact type electromagnetic sensor system and realized the proposed sensor device. From the experiments, the proposed device can be employed for the two dimensional position sensor.

• Journal of Industrial Technology
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• v.27 no.B
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• pp.97-101
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• 2007

We have developed a Edge Position Controller (EPC) using a ultrasonic sensor and applied to a fabric machine as a web guide system. Hardware devices composed of a ultrasonic transmitter-receiver sensor module and microprocessor-based sensor signal processing system are developed to realize the proposed system. We evaluated the control characteristics of the EPC and the performance of the system was good enough to apply the actual system.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.149-154
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• 2002

In a high speed spindle system, it is very important to monitor the state of rotating rotor. Particularly in active control spindle system, the position sensor must provide feedback to the control system on the exact position of the rotor. In order to monitor the state of a high speed spindle exactly, high accuracy and wide frequency bandwidth of sensors are important. This paper observes the factors which has an effect on dynamic performances of inductive position sensor.

• The Transactions of the Korean Institute of Power Electronics
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• v.16 no.4
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• pp.351-357
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• 2011

Rotor position is essentially required for vector control of permanent magnet synchronous generator(PMSG) and position sensor such as encoder are generally used for the purpose of position sensing. However, the use of position sensor degrades reliability of PMSG control system. This paper presents position sensor fault tolerant control method for PMSG control system. Sensorless position estimator based on extended electromotive force(EMF) is operated in parallel with sensored vector control to provide rapid reconfiguration capability to sensorless vector control at the moment of position sensor fault detection. Experimental results show the effectiveness of the proposed method.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.2
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• pp.140-144
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• 2003

A navigation sensor system for outdoor AGV(Automatic Guided Vehicle) using AMR(Anisotropic Magnetoresitive) sensors is described. We derive a formula of the position of AMR sensor using the measured magnetic field intensity due to permanent magnet with constant distance. The system consists of sensor board. sensor control board and position processing board. The sensor board measures magnetic field intensity, the sensor control board controls the measurement of six sensors sequentially, and the position processing board computes the accurate position of the permanent magnet using Least Square Method. We arranged six sensors at intervals of 30cm and measured the position of the permanent magnet moving at intervals of 30cm. Experimental results showed that we can get standard deviation of 2mm and error of &\pm&4.5mm at a height of 20cm from the permanent magnet.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.4
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• pp.290-298
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• 2013

Geomagnetic is refracted by building's wall and pillar. Therefore refracted geomagnetic is able to be used as feature point. In a specific space, a mobile device that is equipped with magnetic sensor array measures 3-axis magnetic field for each point. Magnetic field map is acquired by collecting the every sample point in the magnetic field. The measured magnetic field must be calibrated, because each magnetic sensor has a distortion. For this reason, sensor distortion model and sensor calibration method are proposed in this paper. Magnetic field that is measured by mobile device matches magnetic field map. Result of the matching is used for position estimation. This paper implements hardware system for position estimation method using magnetic field map.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.680-684
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• 1996

Welding systems cannot adapt to changes in the joint geometry which may occur due to a variety of reason. Automatic seam tracking technigue is essential to adjust the welding torch position in real time as it moves along the seam. Automatic tracking system must keep the welding speed constant unrelation to the change of the welding path. Therefore, the information from the laser displacement sensor must be converted into the input to operate the X-Y table and to rotate the desired torch position by proposed algorithm. In this research, laser displacement sensor is used as a seam finder in the automatic tracking system. X-Y moving table manipulated by ac servo motor controls the position and velocity of the torch-and-sensor part. DC motor controls the position and velocity of the torch. X-Y table controls the position of sensor and relative position of torch is controlled by dc motor which is mounted at sensor-and-torch part. Sensor is always ahead of torch to preview the weld line. From the experimental results, we could see the possiblity that the laser displacement sensor can be used as a seam finder in welding process and that the seam tracking system controlled by proposed algorithm is well done.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.207-211
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• 2004

The performance of an inductive position sensor has approved by previous research papers. In this paper, magnetic circuit model of a ring-type multi-pole insuctive position sensor is described. The magnetic circuit model is required to design in ductive position sensor as well as draw a fault tolerance algorithm. Using the magnetic circuit theory, we derived the relationship between voltage applied and flux density in the normal air-gap. By idealizing the modulation/demodulation processes of signal processing circuit, sensor gain with respect to change of displacement is theoretically calculation using the magnetic circuit model, which validate the theoretical derivation.

• Journal of the Korean Society for Railway
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• v.8 no.2
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• pp.155-160
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• 2005

We propose a tram position estimation method for automatic train control system. The accurate train position should be continuously feedback to control system for safe and efficient operation of trains in railway. In this paper, we propose the sensor fusion method integrating a tachometer, a transponder, and a doppler sensor far estimation of train position. The external sensors(transponder, doppler sensor) are used to compensate for the error of internal sensor (tachometer). The Kalman filter is also applied to reduce the measurement error of the sensors. Simulation results are then presented to verify the usefulness of the proposed method.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.65-68
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• 2002

In a high speed spindle system, it is very important to monitor the state of rotating rotor. Particularly in active control spindle system, the position sensor must provide feedback to the control system on the exact position of the rotor. In order to monitor the state of a high speed spindle exactly, High accuracy and wide frequency bandwidth of sensors are important. This paper describes the factors which has an effect on performances of inductive position sensor. We also report the experimental results that characterize the performances of the inductive position sensor.