• Title/Summary/Keyword: Tracker

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Lateral Vehicle Control Based on Active Flight Control Technology

  • Seo Young-Bong;Choi Jae-Weon;Duan Guang Ren
    • Journal of Mechanical Science and Technology
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    • v.20 no.7
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    • pp.981-992
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    • 2006
  • In this paper, a lateral vehicle control using the concept of control configured vehicle (CCV) is presented. The control objectives for the lateral dynamics of a vehicle include the ability to follow a chosen variable without significant motion change in other specified variables. The analysis techniques for decoupling of the aircraft motions are utilized to develop vehicle lateral control with advanced mode. Vehicle lateral dynamic is determined to have the steering input and control torque input. The additional vehicle modes are also defined to using CCV concept. We use right eigenstructure assignment techniques and command generator tracker to design a control law for an lateral vehicle dynamics. The desired eigenvectors are chosen to achieve the desired decoupling (i.e., lateral direction speed and yaw rate). The command generator tracker is used to ensure steady-state tracking of the driver's command. Finally, the developed design is utilized by using the lateral vehicle dynamic with four wheel.

Lateral Vehicle Control Based on Active Flight Control (능동비행제어기술에 기반한 자동차 횡방향 제어)

  • Seo Young-Bong;Duan Guang Ren;Choi Jae-Weon
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.10
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    • pp.1002-1011
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    • 2006
  • In this paper, a lateral vehicle control using the concept of control configured vehicle(CCV) is presented. The control objectives for the lateral dynamics of a vehicle include the ability to commend a chosen variable without significant motion change in other specified variables. The analysis techniques fur decoupling of the aircraft motions are utilized to develop vehicle lateral control with advanced mode. Vehicle lateral dynamic is determined to have the steering input and control torque input. The additional vehicle modes are also defined to using CCV concept. We use right eigenstructure assignment techniques and command generator tracker to design a control law for an lateral vehicle dynamics. The desired eigenvectors are chosen to achieve the desired decoupling(i.e., lateral direction speed and yaw rate). The command generator tracker is used to ensure steady-state tracking of the driver's command. Finally, the developed design is utilized by using the lateral vehicle dynamic with four wheel.

Eye-Tracking on Inservice Elementary Teachers' Interpreting of Science Textbook Tables (과학 교과서의 표를 해석하는 초등교사들의 안구 운동 추적)

  • Choi, Hyun-Dong;Shin, Dong-Hoon
    • Journal of Korean Elementary Science Education
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    • v.31 no.3
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    • pp.358-371
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    • 2012
  • The main purpose of this study was to examine elementary teachers' visual attention that appears in science textbook tables. This paper proposed that teachers' cognitive effectiveness can be different by the presence or absence of the title of tables. The eye fixation data of participants are collected by the eye tracker apparatus. Participants in this study were 10 elementary school teachers and the table on the 2007 revised science textbooks were selected as experimental stimuli. Information about eye-fixations are recorded when subjects are given 4 tables by eye tracker. Eye-fixation time as well as the ratio and the number of fixation can be obtained by using the eye tracker but also we can acquire a significant conclusion through these outcomes. As the result of the experiment, it took less time to interpret in the presence of the title than in the absence of it. However, this result is only effective only for the interpretation of simple stimulus; the presence of title does not influence on fixation time in the analysis of complicated stimulation. This study showed that it is better to insult the title in the tables because it helps teachers to recognize contents of the tables effectively.

Development of Face Tracking System Using Skin Color and Facial Shape (얼굴의 색상과 모양정보를 이용한 조명 변화에 강인한 얼굴 추적 시스템 구현)

  • Lee, Hyung-Soo
    • The KIPS Transactions:PartB
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    • v.10B no.6
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    • pp.711-718
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    • 2003
  • In this paper, we propose a robust face tracking algorithm. It is based on Condensation algorithm [7] and uses skin color and facial shape as the observation measure. It is hard to integrate color weight and shape weight. So we propose the method that has two separate trackers which uses skin color and facial shape as the observation measure respectively. One tracker tracks skin colored region and the other tracks facial shape. We used importance sampling technique to limit sampling region of two trackers. For skin-colored region tracker, we propose an adaptive color model to avoid the effect of illumination change. The proposed face tracker performs robustly in clutter background and in the illumination changes.

Improvement of Earth Gravity Field Maps after Pre-processing Upgrade of the GRACE Satellite's Star Trackers

  • Ko, Ung-Dai;Wang, Furun;Eanes, Richard J.
    • Korean Journal of Remote Sensing
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    • v.31 no.4
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    • pp.353-360
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    • 2015
  • Earth's gravity field recovery was improved after the pre-processing upgrade of the Gravity Recovery And Climate Experiments (GRACE) satellite's star trackers. The star tracker measurements were filtered with a tighter low-pass filtering of 0.025Hz cutoff frequency, instead of a nominal filtering of 0.1Hz cutoff frequency. In addition, a jump removal algorithm was applied to remove discontinuities, due to direct Sun and/or Moon interventions, in the star tracker measurements. During the K-Band Ranging (KBR) calibration maneuvers, large attitude variations could be detected concurrently by both of the star trackers and the accelerometer. The misalignment angles of star trackers between the true frame and the normal frame could be determined by comparing measurements from these sensors. In this paper, new Earth' gravity field maps were obtained using above improvement. Based on comparisons to nominal Earth's gravity field maps, the new Earth's gravity field maps were found better than the nominal ones. Among the applied methods, the misalignment calibration of the star trackers had a major impact on the improvement of the new Earth's gravity field maps.

A Counter-Countermeasure using Signal Distribution Characteristics between Two Bands in a Crossed Array Tracker (십자 배열 탐색기에서의 두 대역간 신호 분포 특성을 이용한 반대응 능력)

  • 이석한;오정수;서동선;최종수
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.4A
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    • pp.316-323
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    • 2002
  • In this paper, we propose a counter-countermeasure (CCM) in a crossed array tracker for efficient target tracking under countermeasures (CM) operated by a target. The proposed CCM adepts two detection bands and uses the signal distribution characteristics to discriminate between the target and the CMs. To avoid wrong detection of a target position due to missing signal pulses, it predicts current target position based on previous target position. To evaluate the performance of the proposed CCM in a crossed array tracker, we perform numerical simulations for target signal extraction and target tracking under various conditions. The simulation results show that the proposed CCM removes the CM effect well and tracks the target efficiently.

A study on the consumer's visual reaction about display props of clothing store - Focus on visual behavior using eye-tracker - (의류매장 디스플레이 소도구에 대한 소비자의 시각반응 연구 - 아이트래커를 활용한 시각행동 중심으로 -)

  • Kim, Young-Me;Kim, G-Ho
    • Journal of Fashion Business
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    • v.14 no.5
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    • pp.35-48
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    • 2010
  • As measuring visual behavior by utilize eye-tracker, this study examines whether consumer concentrates on visual attention with certain object and measures visual behavior with fixation number, fixation duration, the first fixation, which are visual attention pattern of consumer about Mannequin, hanger, shelve as props of display advertising effect on clothing store. It has experimental purpose to recognize relationships in terms of regardless, appropriateness, purchase intention. During display of clothing store, first experimental consequence to measure visual behavior on consumer did appear to allocate more cautions than other props. Second, in terms of relationships with regardless, appropriateness, purchase intention from consumer, each fixation pattern about consumer's fixation number, fixation duration, the first fixation was confirmed that there is meaningful correlation with each other. Accordingly, as advertising effect of mannequin makes consumer to concentrate more visually cautious, it is translated that high favor about display product with mannequin has positive role on purchase intention. Also, there is a purpose that higher feasibility on study result provides practical point on clothing store's display marketing strategy of corporation.

Extended kernel correlation filter for abrupt motion tracking

  • Zhang, Huanlong;Zhang, Jianwei;Wu, Qinge;Qian, Xiaoliang;Zhou, Tong;FU, Hengcheng
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.9
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    • pp.4438-4460
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    • 2017
  • The Kernelized Correlation Filters (KCF) tracker has caused the extensive concern in recent years because of the high efficiency. Numerous improvements have been made successively. However, due to the abrupt motion between the consecutive image frames, these methods cannot track object well. To cope with the problem, we propose an extended KCF tracker based on swarm intelligence method. Unlike existing KCF-based trackers, we firstly introduce a swarm-based sampling method to KCF tracker and design a unified framework to track smooth or abrupt motion simultaneously. Secondly, we propose a global motion estimation method, where the exploration factor is constructed to search the whole state space so as to adapt abrupt motion. Finally, we give an adaptive threshold in light of confidence map, which ensures the accuracy of the motion estimation strategy. Extensive experimental results in both quantitative and qualitative measures demonstrate the effectiveness of our proposed method in tracking abrupt motion.

On-Orbit AOCS Sensor Calibration of Spacecraft (인공위성의 궤도상에서 자세제어계 센서 보정)

  • Yong, Gi-Ryeok;Lee, Seon-Ho;O, Si-Hwan;Bang, Hyo-Chung;Lee, Seung-U
    • Aerospace Engineering and Technology
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    • v.5 no.2
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    • pp.90-101
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    • 2006
  • In this paper, the calibration parameters of the gyros and star hackers are estimated by using an on-orbit AOCS sensor calibration algorithm. The calibration algorithm was implemented by Kalman filter. In order to estimate gyro calibration parameters, the calibration algorithm requires calibration maneuver and it was analyzed whether the star trackers are protected by Sun, Moon and Earth or not. Also the star tracker calibration algorithm used the camera image information. This kinds of camera image information simulated ground control point and orbit information. The estimated accuracy of star tracker calibration parameters depends on camera image information.

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The Effective Error Correction Method of a Camera in Monitor-based Augmented Reality Systems (모니터 기반 Augmented Reality 시스템에서 카메라 오차의 효율적인 보정 방법)

  • Kim, Juwan;Kim, Haedong;Jang, Byungtae;Kim, Donghyun
    • Journal of the Korea Computer Graphics Society
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    • v.3 no.2
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    • pp.35-43
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    • 1997
  • In monitor-based AR(Augmented Reality) systems, it is required to know the position and direction of a camera in order to combine real images from a camera with virtual images exactly_ Because a tracker is parted from a camera, however, there is a registration error caused by the inconsistency of a tracker with a camera. In this paper, we describe the error correction method using genetic algorithm. This method looks for the position and direction of a camera using genetic algorithm and solves the error correction matrix of it. And then it is registered of the real images and the revised virtual image. It has an effect on the error correction caused by the misalignment of a tracker with a camera in complex AR systems.

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