• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.5
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• pp.40-47
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• 2012

The PMSM position sensor using two rectangular hall sensors can restrictively acquire the 90[$^{\circ}$] position information of rotor according to electrical angle. Thus, the control method using this position sensor cannot react properly to a rapid load torque change. On the other hand, even though a sensorless method has the advantage of acquiring instantaneous rotor position information, the accuracy of position sensor can be determined by the gain value of estimator. This paper suggests a robust speed control method on torque fluctuation condition, which combines low cost two rectangular hall sensors and sensorless control method.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.5
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• pp.50-56
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• 2015

As rotor position is a reference of coordinate in vector control of PMSM, the information of exact rotor position is required. To measure the position of motors, hall-effect sensors, encoders, resolvers, etc. are used. Among these sensors, resolvers have good endurance in the variation of circumstance and can be used in a wide range of temperature, but resolvers are less exact than encoders. In addition, resolvers have a drawback that the output signal contains periodic error components. Thus, this paper proposes a compensation method for the unique position error in resolvers using Kalman filter to achieve high performance control of PMSM. The validity of the proposed scheme is demonstrated through simulation studies.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.10
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• pp.58-66
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• 2008

In the development of intelligent vehicles, path tracking of unmanned vehicle is a basis of autonomous driving and automatic navigation. It is very important to find the exact position of a vehicle for the path tracking, and it is possible to get the position information from GPS. However the information of GPS is not the current position but the past position because a vehicle is moving and GPS has a time delay. In this paper, therefore, the moving distance of a vehicle is estimated using a direction sensor and a velocity sensor to compensate the position error of GPS. In the steering control, optimal fuzzy rules for the path tracking can be found through the simulation of Simulink. Real driving experiments show the fuzzy rules are good for the steering control and the position error of GPS is well compensated by the proposed estimation method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.3
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• pp.627-633
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• 2007

This paper describes position tracking system of a container trailer approaching to a gantry crane for loading or unloading a container into or from a ship, respectively. Proposed position tracking system informs the trailer driver of right position to stop the car under a gantry crane. To measure the location of a trailer, we used Cricket Mote modules which adopted RF and ultrasound technology. We present an elaborate method to improve position errors occurring at sensing and calculate three dimensional position by triangulation along with how to reduce location tracking interval for real-time monitoring. The location information was transmitted to a Personal Digital Assistant (PDA) periodically through Bluetooth communication for guidance of the trailer driver. In indoor and outdoor tests, position errors were less than 3 cm and location tracking interval was 0.5 second on average.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.6
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• pp.1123-1128
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• 2016

Recently BLE beacon has been widely used as a method for measuring the indoor location in the IoT Technique. But it requires a filtering technique for the measurement of the correct position. It is used the most fixed beacon. It is not accurate that calculates the position information through the identification of the beacon signal. Therefore, filtering is important. So it takes a lot of time, position measurement and filtering. Thus, we is to measure the exact position at the indoor using a mobile beacon. The measured beacon signal is composed of an ontology for reuse in the same pattern. RSSI is measured the receiver is the distance of the beacon. And this value configure the location ontology to be normalized by the relationship analysis between the values. The ontology is a method for calculating the position information of the moving beacon. It can detect fast and accurate indoor position information and provide the service.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.1
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• pp.226-232
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• 2015

As the age of smart device has come, recently many application services related to smart phone are developing. The LBS(Location Based Service) technique is considered as one of the most important techniques to support location based application services. Usually the smart phone acquires the information of position by using the position recognition systems and sensors such as GPS(Global Positioning System) and G-Sensor. However, since the GPS signal from the satellite can hardly be received in the indoor environments, new LBS techniques for the indoor environment are required. In this paper, to solve the problem a position information transceiver using LED lights and smart phone camera sensor is proposed. We proved the possibility of the proposed positioning system through the experiments in the laboratory for the practical verification.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.81-85
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• 2003

For the structure of VMS by converting on digital the position reporting of departure fishery ship in the fishery communication that be required the management ＆ operation of information in organizational. In particular, Must be made the regional ＆ concentrational of the position reporting information. The division of region is considered to the circumstance of radio wave, fishing area, quantity of fishery ship and communication traffic etc., which is capable to the DB of VMS by be concentrated in oeadquarters, which is acquisition the position reporting information of respective region. In this study have designed for building of fishery information network and automatic transmission of the position reporting information from a fishery ship.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.5
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• pp.1400-1420
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• 2012

Object detection and tracking using visual sensors is a critical component of surveillance systems, which presents many challenges. This paper addresses the enhancement of object detection and tracking via the combination of multiple visual sensors. The enhancement method we introduce compensates for missed object detection based on the partial detection of objects by multiple visual sensors. When one detects an object or more visual sensors, the detected object's local positions transformed into a global object position. Local and global information exchange allows a missed local object's position to recover. However, the exchange of the information may degrade the detection and tracking performance by incorrectly recovering the local object position, which propagated by false object detection. Furthermore, local object positions corresponding to an identical object can transformed into nonequivalent global object positions because of detection uncertainty such as shadows or other artifacts. We improved the performance by preventing the propagation of false object detection. In addition, we present an evaluation method for the final global object position. The proposed method analyzed and evaluated using case studies.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.278-279
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• 2015

Recently, With the development of smart devices of interest in the intelligent indoor positioning service with a smart terminal it is increasing. The BLE(Bluetooth Low Energy) is an indoor location positioning technology has attracted the attention. However, there is no way to check the reliability of the position information collected by the smart terminal receiving a big location data. This is because the reliability of an indoor position information because of a signal interference to drop. In this paper, we propose a method of managing big data collected in order to obtain reliable position information from the position information of iBeacon.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.7
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• pp.1387-1392
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• 2003

For the structure of VMS by converting on digital the position reporting of departure fishery ship in the fishery communication that be required the management & operation of information in organizational. In particular, Must be made the regional & concentrational of the position reporting information. The division of region is considered to the circumstance of radio wave, fishing area, quantity of fishery ship and communication traffic etc.. It is capable to the DB of VMS by concentrate in head quarters, which is acquisition the position reporting information of respective region. In this study have designed for building of fishery information network and automatic transmission of the position reporting information from a fishery ship.