• Title/Summary/Keyword: Estimated Position

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Source finding in reflection and refraction environment using based on ray tracing method TRM (음선 추적법 기반 TRM을 이용한 반사 및 굴절 환경 속의 소음원 탐색에 대한 연구)

  • Moon, Sang Il;Lee, Jae Hyung;Choi, Jong Soo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2014.10a
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    • pp.727-732
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    • 2014
  • The goal is to find the position of the sound source with the TRM at reflections and refractions environment. The Fermat's principle applied to the ray tracing method are expected to follow the acoustic path in order to obtain acoustic distance and transmittance to. Utilizing them in the TRM was confirmed rear reflectance affect on estimated position, resolution and side lobe. And the TRM performance were superior to one of the beam forming techniques.

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Artificial Landmark Design and Recognition for Localization (위치추정을 위한 인공표식 설계 및 인식)

  • Kim, Si-Yong;Lee, Soo-Yong;Song, Jae-Bok
    • The Journal of Korea Robotics Society
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    • v.3 no.2
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    • pp.99-105
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    • 2008
  • To achieve autonomous mobile robot navigation, accurate localization technique is the fundamental issue that should be addressed. In augmented reality, the position of a user is required for location-based services. This paper presents indoor localization using infrared reflective artificial landmarks. In order to minimize the disturbance to the user and to provide the ease of installation, the passive landmarks are used. The landmarks are made of coated film which reflects the infrared light efficiently. Infrared light is not visible, but the camera can capture the reflected infrared light. Once the artificial landmark is identified, the camera's relative position/orientation is estimated with respect to the landmark. In order to reduce the number of the required artificial landmarks for a given environment, the pan/tilt mechanism is developed together with the distortion correction algorithm.

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A Moving Target Tracking Algorithm Using Integral Projection (가산 투엽법을 이용한 이동 물체 추적 방법)

  • 김태원;서일홍;양해원;오상록;임달호
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.38 no.7
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    • pp.569-581
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    • 1989
  • This paper deals with a tracking algorithm based on integral projection which tracks moving targets with varying brightness and size. An adaptive windowing technique is employed to reduce the sensitivity of the system to the complex background image and also to reduce the computational load. The threshold value is determined by considering both the size and the threshold value of the brightness intensity of the recognized target obtained in the previous processing step. Window position is estimated by using the information of the velocity and acceleration of the target. And integral projection is applied to find the position of the target in the window accurately. Experimental results show that moving targets with varying brightness and size can be tracked properly in noisy environments.

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Sensorless Control for a PM Synchronous Motor in a Single Piston Rotary Compressor

  • Cho Kwan-Yuhl
    • Journal of Power Electronics
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    • v.6 no.1
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    • pp.29-37
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    • 2006
  • A sensorless control for an IPM (Interior Permanent Magnet) synchronous motor in a single piston rotary compressor is presented in this study. The rotor position is estimated from the d-axis and q-axis current errors between the real system and a motor model of the position estimator. The torque pulsation of the single piston rotary compressor is compensated to reduce speed ripples, as well as, mechanical noise and vibration. The proposed sensorless drive enables the compressor to operate at a lower speed which increases energy savings and reduces mechanical noise. It also gives high speed operations by a flux weakening control for rapid air-cooling and heating of the heat pump air-conditioners.

Sensorless Vector Control of Induction Motor with HAI Controller (HAI 제어기에 의한 유도전동기의 센서리스 벡터제어)

  • Lee, Jung-Chul;Lee, Hong-Gyun;Chung, Dong-Hwa
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.54 no.2
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    • pp.73-79
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    • 2005
  • This paper is proposed hybrid artificial intelligent (HAI) controller based on the vector controlled induction motor drive system. The hybrid combination of fuzzy control and neural network will produce a powerful representation flexibility and numerical processing capability. Also, this paper is proposed speed estimation of induction motor using a closed-loop state observer. The rotor position is calculated through the stator flux position and an estimated flux value of rotation reference frame. A closed-loop state observer is implemented to compute the speed feedback signal. The results of analysis prove that the proposed control system has strong robustness to rotor parameter variation, and has good steady-state accuracy and transitory response.

Analysis of Residual and Applied Stresses of Thin-walled U tubes (얇은 두께로 된 U 전열관의 잔류응력 및 부하응력 해석)

  • 김우곤;김대환;류우석;국일현;김성청
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1999.05a
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    • pp.163-169
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    • 1999
  • Residual stresses causing stress corrosion cracking (SCC) of thin-walled steam generator U tubes were investigated. The residual stresses were measured by hole drilling methods, and the applied stresses resulting from the internal pressure and the temperature gradient in the steam generator were estimated theoretically. In U-bent regions, the residual stresses at extrados were induced with compressive stress(-), and its maximum value reached -319MPa in axial direction at $\phi$= $0^{\circ}$ in position. Maximum tensile residual stress of 170MPa was found to be at the flank side at position of $\phi$= $90^{\circ}$, i.e., at apex region. Hoop stress due to the pressure and temperature differences between primary and secondary side were analyzed to be 76 MPa and 45 MPa, respectively.

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Performance Enhancement of Soccer Robot System by Changing Color Patch (칼라 패치 변경을 이용한 축구 로봇 시스템의 성능 개선)

  • Ko, Chang-Gun;Jang, Mun-Hee;Lee, Suk-Gyu
    • IEMEK Journal of Embedded Systems and Applications
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    • v.4 no.3
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    • pp.118-125
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    • 2009
  • This paper proposes a novel method to enhance performance of soccer robot system using optimal color patch mounted on the robot. In soccer robot system, the position and orientation of the robot can be estimated with color patch under real time environment. However, the location estimation of the robot is very sensitive to the pattern of color patch. In addition, pattern recognition and navigation algorithm are operated independently to reduce the operation time. The experimental results show that the proposed pattern of patch is effective to reduce the position and orientation error of the robot.

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Identification of Flexion Withdrawal Reflex Using Linear Model in Spinal Cord Injury

  • Kim Yong-Chul;Youm Youn-Gil
    • Journal of Mechanical Science and Technology
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    • v.20 no.8
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    • pp.1183-1194
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    • 2006
  • The aim of this study was to identify the characteristics of the flexion withdrawal reflex modulated by the hip angle and hip movement in spinal cord injury (SCI). The influence of the hip position and passive movement were tested in 6 subjects with chronic SCI. Each subject placed in a supine position and lower leg was fixed with the knee at 5 -45 degree flexion and the ankle at 25-40 degree plantar flexion. A train of 10 stimulus pulses were applied at 200 Hz to the skin of the medial arch to trigger flexion reflexes. From results of the regression analysis, static properties of normalized muscle activation of flexor muscles have the linear relationship with respect to hip angle (P< 0.05). In order to verify the neural contribution of flexion reflex, we compared the static and dynamic gains of estimated muscle activations with measured EMG of ankle flexor muscle. Form this study, we postulate that the torque and muscle response of flexion withdrawal reflex have linear relationship with hip angle and angular velocity.

An Indoor Positioning Method using IEEE 802.11 Channel State Information

  • Escudero, Giovanni;Hwang, Jun Gyu;Park, Joon Goo
    • Journal of Electrical Engineering and Technology
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    • v.12 no.3
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    • pp.1286-1291
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    • 2017
  • In this paper, we propose an indoor positioning system that makes use of the attenuation model for IEEE 802.11 Channel State Information (CSI) in order to determine its distance from an Access Point (AP) at a fixed position. With the use of CSI, we can mitigate the problems present in the use of Received Signal Strength Indicator (RSSI) data and increase the accuracy of the estimated mobile device's location. For the experiments we performed, we made use of the Intel 5300 Series Network Interface Card (NIC) in order to receive the channel frequency response. The Intel 5300 NIC differs from its counterparts in that it can obtain not only the RSSI but also the CSI between an access point and a mobile device. We can obtain the signal strengths and phases from subcarriers of a system which in turn means making use of this data in the estimation of a mobile device's position.

A Simplified Sensorless Control of Synchronous Reluctance Motor Using MATLAB (동기형 릴럭턴스 전동기의 단순구조형 센서리스 제어)

  • Lim Jin-Jae;Kim Sol;An Joon-Seon;Lee Ju;Kim Yun-Hun
    • Proceedings of the KIEE Conference
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    • summer
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    • pp.848-850
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    • 2004
  • Complex sensorless control scheme is difficult to utilize in field of home appliance system because of cost problem. Therefore, it is necessary to introduce simplified sensorless control scheme that is composed of least calculation to estimate the rotor position. This paper presents the principle of the rotor position estimation with comparison of the estimated flux linkage and reference flux linkage. In order to verify the feasibility of control scheme, simulation with MATLAB and experiment is performed.

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