• 전력전자학회논문지
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• 제13권1호
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• pp.41-45
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• 2008

본 논문에서는 홀센서와 같은 자극위치 센서를 사용하지 않는 Z축 선형 영구자석 동기전동기의 초기 자극위치 추정에 관한 알고리즘을 제안한다. 제안된 알고리즘은 Z축의 경우에 존재하는 중력에 의한 자체하중의 영향을 고려하고, 부하질량 변동에 따른 추정특성 변화를 회피하기 위한 방법을 제시하며, 2단계로 구성되어 있다. 1단계에서는 미리 정한 각도 간격의 시험 q축에 전류를 인가하여 구한 이동거리를 사용하여 근사적인 q축을 추정한다. 2단계에서는 1단계의 추정치를 초기치로 이용하며, 부하질량의 영향을 받지 않도록 하기 위하여 3개의 시험 q축에 인가한 전류에 따른 추력에 대응하는 값을 이용하여 자극위치를 정밀하게 추정한다. 그리고 Z축 PMLSM에 대한 실험 결과를 통하여 제안된 초기 자극위치 추정방법으로 부하질량 조건에 관계없이 정밀하게 자극위치를 추정함을 검증하였다.

• 한국공작기계학회논문집
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• 제10권1호
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• pp.36-42
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• 2001

In this paper, PSD(Position Sensitive Detector) sensor system that estimates position for moving objects in 2D plane is developed. PSD sensor is used to measure the position the position of and incidence light in real-time. To get the position of light source of moving target, a new parameter calibration algorithm and neural network technique are proposed and applied. Real-time position measurements of the mobile robot with light source is examined to validate the proposed method. It is shown that the proposed technique provides accurate position estimation of the moving object.

• Journal of Power Electronics
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• 제14권5호
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• pp.957-966
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• 2014

Some of DC actuators used in home automation, office automation, medical equipment and automotive systems require a position sensor. In low power applications, the introduction of such a transducer remarkably increases the whole system cost, which justifies the development of sensorless position estimation techniques. The well-known AC motor drive sensorless techniques exploiting the fundamental component of the back electromotive force cannot be used on DC motor drives. In addition, the sophisticated approaches based on current or voltage signal injection cannot be used. Therefore, an effective and inexpensive sensorless position estimation technique suitable for DC motors is presented in this paper. This technique exploits the periodic pulses of the armature current caused by commutation. It is based on a simple pulse counting algorithm, suitable for coping with the rather large variability of the pulse frequency and it leads to the realization of a sensorless position control system for low cost, medium performance systems, like those in the field of automotive applications.

• 대한안전경영과학회지
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• 제20권2호
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• pp.37-44
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• 2018

The Location Based Service is growing rapidly nowadays due to the universalization of the use for smartphone, and therefore the location determination technology has been placed in a very important position. This study suggests an algorithm that can provide the estimate of users' location by using smartphone sensors. And in doing so we will propose a methodology for the creation and update of indoor map through the more accurate position estimation using smartphone sensors such as acceleration sensor, gyroscope sensor, geomagnetic sensor and rotation sensor.

• 한국통신학회논문지
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• 제15권12호
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• pp.1002-1016
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• 1990

본 논문은 스테레오비젼 시스템을 설계 제작하고, 제작된 시스템을 가지고 3차원 이동물체의 변위평가 방법을 제안하였다. 이동물체의 추출은 차영상 알고리즘에 의해 추출하고, 3차원 이동물체의 기하학적인 위치좌표는 2개의 2차원 물체의 면적중심을 합성시켜 구하였다. 3차원 이동물체의 범위평가는 합성된 3차원 좌표값에 의해서 물체의 이동속도 및 거리, 이동궤적, 카메라와 물체 사이의 공간거리를 산출하여 입증하였다.

• Journal of Electrical Engineering and Technology
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• 제8권3호
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• pp.613-620
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• 2013

A new remote control algorithm for a mobile robot is proposed, where a remote controller consists of a camera and inertial sensors. Initially the relative position and orientation of a robot is estimated by capturing four circle landmarks on the plate of the robot. When the remote controller moves to point to the destination, the camera pointing trajectory is estimated using an inertial navigation algorithm. The destination is transmitted wirelessly to the robot and then the robot is controlled to move to the destination. A quick movement of the remote controller is possible since the destination is estimated using inertial sensors. Also unlike the vision only control, the robot can be out of camera's range of view.

• ETRI Journal
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• 제45권5호
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• pp.758-767
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• 2023

In this study, we introduce a loosely coupled relative position estimation method that utilizes a decentralized ultrawideband (UWB), Global Navigation Support System and inertial navigation system for flight controllers (FCs). Key obstacles to multidrone collaboration include relative position errors and the absence of communication devices. To address this, we provide an extended Kalman filter-based algorithm and module that correct distance errors by fusing UWB data acquired through random communications. Via simulations, we confirm the feasibility of the algorithm and verify its distance error correction performance according to the amount of communications. Real-world tests confirm the algorithm's effectiveness on FCs and the potential for multidrone collaboration in real environments. This method can be used to correct relative multidrone positions during collaborative transportation and simultaneous localization and mapping applications.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권2호
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• pp.574-592
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• 2016

Range-free localization algorithm computes a normal node's position by estimating the distance to anchors which know their actual position. In recent years, reliable anchor selection research has been gained a lot of attention because this approach improves localization accuracy by selecting the only subset of anchors called reliable anchor. The distance estimation accuracy and the geometric shape formed by anchors are the two important factors which need to be considered when selecting the reliable anchors. In this paper, we study the relationship between a relative position of three anchors and localization error. From this study, under ideal condition, which is with zero localization error, we find two conditions for anchor selection, thereby proposing a novel anchor selection algorithm that selects three anchors matched most closely to the two conditions, and the validities of the conditions are proved using two theorems. By further employing the conditions, we finally propose a novel range-free localization algorithm. Simulation results show that the proposed algorithm shows considerably improved performance as compared to other existing works.

• 대한전기학회논문지:전력기술부문A
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• 제48권12호
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• pp.1537-1543
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• 1999

In this paper, PSD(Position Sensitive Detector) sensor system that estimates position for moving objects in 2D plane is developed. PSD sensor is used to measure the position of an incidence light in real-time. To get the position of light source of moving target, a new parameter calibration algorithm and neural network technique are proposed and applied. Real-time position measurements of the mobile robot with light source is examined to validate the proposed method. It is shown that the proposed technique provides accurate position estimation of the moving object.

• 조명전기설비학회논문지
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• 제22권3호
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• pp.66-73
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• 2008

This paper presents a position sensorless control system of SRM over wide speed range. Due to the doubly salient structure of the SRM, the phase inductance varies along with the rotor position. Most of the sensorless control techniques are based on the fact that the magnetic status of the SRM is a function of the angular rotor position. The rotor position estimation of the SRM is somewhat difficult because of its highly nonlinear magnetizing characteristics. In order to estimate more accurate rotor position over wide speed range, Neural Network is used for this highly nonlinear function approximation. Magnetizing data patterns of the prototype 1-hp SRM are obtained from locked rotor test, and used for the Neural Network training data set. Through measurement of the flux-linkage and phase currents, rotor position is able to estimate from current-flux-rotor position lookup table which is constructed from trained Neural Network. Experimental results for a 1-hp SRM over 16:1 speed range are presented for the verification of the proposed sensorless control algorithm.