• Proceedings of the KIEE Conference
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• 2006.10d
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• pp.238-240
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• 2006

For the method of train position detection, ground-based train position estimation mainly has been applied so far. Ground-based position detection is the way to detect train current positions by installing train position equipments on railroad lines. However, the ground-based methods should install detection equipments on each section, and can only be able to detect train positions from main command center. So this method has several disadvantages such as an discontinuous position detection, an increment in cost of installation and maintenance. To make possible continuous train position detection, and to minimize amount of the cost, the vehicle-based position detection method should be chosen to determine train positions by loading position equipments on vehicles. In this paper, to realize the vehicle-based train position detection method, configuration scheme of train position detection equipment is suggested by using GPS, inertial sensor, speed sensor and its performance is verified by simulations.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.04a
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• pp.201-205
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• 2007

This paper proposes a link model that can provide the spacial position along the surface of the earth as an information or data using ePosition ID through the Internet. Moreover, to support the information service of maritime position, it needs the ENC linked technique based on S-57 that is an IHO transfer standard for digital hydrographic data. Therefore, it designs the linked model for applying and utilizing the ePosition technology with ENC data, as well as supplementing the base technology in applying them to marine related fields. As a study method, this paper first analyses ENC data model and structure, and converses for processing of ENC file to ePosition data. Finally, it derives the interconnection method with ePosition database and shows the ePosition service application based on the linked ENC data and its validity.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.85.1-85
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• 2002

In this paper, a control strategy of position and force is proposed based on a switching algorithm. The main focus is the control of position and force in the same direction. The switching algorithm based on a fuzzy algorithm determines the weighting value of force control. First, the force control is dominant. If the position gets closer to the desire position, the weighting value of force control is closer to zero. The proposed algorithm is shown to be satisfactory to position and force control and the weighting factor is quite successful by simulation examples.

• Proceedings of the KIEE Conference
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• 2005.04a
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• pp.200-202
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• 2005

In this paper, improved rotor position estimation for position sensorless control system of the SRM (Switched Reluctance Motor) is presented. For more accurate rotor position estimation, the PLL (Phase Locked Loop) based position interpolation is adapted. In the current-flux-rotor position lookup table based rotor position estimation, the inherent current and flux-linkage ripple can cause the position estimation error. Instead of the conventional low-pass filter, the PLL based position interpolation technique is used for the better dynamic performance. The developed rotor position estimation scheme is realized using TMS320F2812 digital signal processor and prototype 1-hp SRM.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.7
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• pp.1305-1310
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• 2007

ePosition is a technology that can provide the spacial position of the earth to the information of ePosition ID through the Internet. It is serving the information of land location based on the Internet using the ePosition technology now, but it needs the service technique which can supply the marine data and the information of maritime position. Moreover, to support the information service of marine position, it needs the ENC linked technique based on S-57 that is an IHO transfer standard for digital hydrographic data. In this paper, therefore, it develops a linkage method for applying and utilizing the ePosition technology to ENC data, and supplements the base technology for applying it to marine related fields. As study method, firstly, this paper analyses ENC data model and structure, and converses for processing ENC file to ePosition data. Lastly, it derives the interconnection method with ePosition database and shows the ePosition service application based on the linked data and its validity.

• Journal of Positioning, Navigation, and Timing
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• v.8 no.4
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• pp.183-192
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• 2019

In fingerprint-based wireless positioning, it is necessary to establish a DB of the unmeasured area. To this end, a method of estimating the position of a base station based on a signal propagation model, and a method of estimating the information of the received signal in the unmeasured area based on the estimated position of the base station have been investigating. The purpose of this paper is to estimate the position of the base station using the measured information and to analyze the performance of the positioning. Vehicles equipped with a GPS receiver and signal measuring equipment travel the service area and acquire location-based Reference Signal Received Power (RSRP) measurements. We propose a method of estimating the position of the base station using the measured information. And the performance of the proposed method is analyzed on a simulation basis. The simulation results confirm that the accuracy of the positioning is affected by the measured area and the Dilution of Precision (DOP), the accuracy of the position information obtained by the GPS receiver, and the errors of the signal included in the RSRP. Based on the results of this paper, we can expect that the position of the base station can be estimated and the DB of the unmeasured area can be constructed based on the estimated position of the base stations and the signal propagation model.

• Journal of Power Electronics
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• v.11 no.2
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• pp.140-147
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• 2011

In this paper, a novel position controller based on state feedback and feed-forward is proposed. Traditional position and speed controllers are replaced by a single controller with the position and speed as state feedbacks, and the position command and load torque as feed-forwards. The feedback and feed-forward gains are obtained by analytic modeling and design. The load torque, rotor speed and position are estimated by an observer based on a Kalman filter (KF) with a low resolution mechanical position sensor. Feed-forward compensation by an estimated load torque is used to improve the dynamic performance during load torque changes.

• The Journal of Korean Physical Therapy
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• v.24 no.2
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• pp.57-65
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• 2012

Purpose: This study was to investigate the effect of biomechanical intervention, based on the custom seating system on the activities of a mouse click for children with cerebral palsy. Methods: Thirteen children with cerebral palsy participated in this study. We compared reaction time and frequency for proper mouse click in the subject's typical position, in addition to an intervention position. The intervention position conformed to the principle and practice of research on promoting the upper-extremity movement and postural control. The intervention position was achieved through an external postural support, which was based on the custom seating system. Results: Reaction time and frequency for proper mouse click were moderately improved in the intervention position, compared with that of the typical position. There was a statistically significant difference between the typical position and that of the intervention position (p<0.05). Conclusion: Results provide evidence of the positive effects of functional seating on the activities of a mouse click for children with cerebral palsy.

• International Journal of Precision Engineering and Manufacturing
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• v.6 no.3
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• pp.29-36
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• 2005

With the rapid growth of the Internet, the Internet-based robot has been realized by connecting off-line robot to the Internet. However, because the Internet is often irregular and unreliable, the varying time delay in data transmission is a significant problem for the construction of the Internet-based robot system. Thus, this paper is concerned with the development of an Internet-based robot system, which is insensitive to the Internet time delay. For this purpose, the PPS (Position Prediction Simulator) is suggested and implemented on the system. The PPS consists of two parts : the robot position prediction part and the projective virtual scene part. In the robot position prediction part, the robot position is predicted for more accurate operation of the mobile robot, based on the time at which the user's command reaches the robot system. The projective virtual scene part shows the 3D visual information of a remote site, which is obtained through image processing and position prediction. For the verification of this proposed PPS, the robot was moved to follow the planned path under the various network traffic conditions. The simulation and experimental results showed that the path error of the robot motion could be reduced using the developed PPS.

• Journal of Biosystems Engineering
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• v.15 no.2
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• pp.79-87
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• 1990

An automatic guidance system based upon two position-measurement systems was designed to record where the tractor traveled and to guide the tractor along the predetermined path. An algorithm, using the kinematic behavior of tractor movement, was developed to determine the steering angle to reduce lateral position error. The algorithm was based upon constant travel speed, constant steering rate, and zero slip angles of the tractor wheels. The algorithm was evaluated through use of computer simulation and verified in field experiments. Results showed that the distance interval between position measurements was an important factor in guidance system performance. The position-measurement error of the guidance system must be less than 5 cm to be acceptably precise for field operations. An algorithm based upon a variable steering rate might improve the stability of the guidance system. More accurate measurement of tractor position and yaw angle, and faster error processing are required to improve the field performance of the guidance system.