• Title/Summary/Keyword: vision-based control

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Wavelet Analysis to Real-Time Fabric Defects Detection in Weaving processes

  • Kim, Sung-Shin;Bae, Hyeon;Jung, Jae-Ryong;Vachtsevanos, George J.
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.2 no.1
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    • pp.89-93
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    • 2002
  • This paper introduces a vision-based on-line fabric inspection methodology of woven textile fabrics. Current procedure for determination of fabric defects in the textile industry is performed by human in the off-line stage. The advantage of the on-line inspection system is not only defect detection and identification, but also 벼ality improvement by a feedback control loop to adjust set-points. The proposed inspection system consists of hardware and software components. The hardware components consist of CCD array cameras, a frame grabber and appropriate illumination. The software routines capitalize upon vertical and horizontal scanning algorithms characteristic of a particular deflect. The signal to noise ratio (SNR) calculation based on the results of the wavelet transform is performed to measure any deflects. The defect declaration is carried out employing SNR and scanning methods. Test results from different types of defect and different style of fabric demonstrate the effectiveness of the proposed inspection system.

Determining priorities for evaluation accreditation to assess dental hygiene education programs (치위생교육인증평가를 위한 평가인증 우선순위 결정)

  • Kim, Chang-Hee;Seong, Mi-Gyung;Lee, Sun-Mi
    • Journal of Korean society of Dental Hygiene
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    • v.18 no.5
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    • pp.643-652
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    • 2018
  • Objectives: The purpose of this study was to review the systems used to evaluate dental hygiene education and to establish priorities for the evaluation index for accreditation to enhance competitiveness and facilitate quality control of dental hygiene education. Methods: A survey of priorities for accreditation evaluation was developed based on input from professors at 43 universities. Data were analyzed using the Analytic Hierarchy Process method with Expert Choice 2000 software. Results: The relative importance of each evaluation area, ranked in descending order, was as follows: vision and operating system; administration and finances; facilities and equipment; educational outcomes; professors; educational process; and students. The importance of the evaluation part was highest in field training at the education process part and scholarship at the student part. The importance after applying complex weights was highest in establishing a development plan for the vision and operating system. Conclusions: Practical accreditation evaluation based on objectivity and validity is needed to control the quality of dental hygiene education. Therefore, priorities in accreditation evaluation standard must be determined to establish a basis for quality improvement in education at dental hygiene departments.

The Effect of Gesture-Command Pairing Condition on Learnability when Interacting with TV

  • Jo, Chun-Ik;Lim, Ji-Hyoun;Park, Jun
    • Journal of the Ergonomics Society of Korea
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    • v.31 no.4
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    • pp.525-531
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    • 2012
  • Objective: The aim of this study is to investigate learnability of gestures-commands pair when people use gestures to control a device. Background: In vision-based gesture recognition system, selecting gesture-command pairing is critical for its usability in learning. Subjective preference and its agreement score, used in previous study(Lim et al., 2012) was used to group four gesture-command pairings. To quantify the learnability, two learning models, average time model and marginal time model, were used. Method: Two sets of eight gestures, total sixteen gestures were listed by agreement score and preference data. Fourteen participants divided into two groups, memorized each set of gesture-command pair and performed gesture. For a given command, time to recall the paired gesture was collected. Results: The average recall time for initial trials were differed by preference and agreement score as well as the learning rate R driven by the two learning models. Conclusion: Preference rate agreement score showed influence on learning of gesture-command pairs. Application: This study could be applied to any device considered to adopt gesture interaction system for device control.

Simultaneous Localization & Map-building of Mobile Robot in the Outdoor Environments by Vision-based Compressed Extended Kalman Filter (Compressed Extended Kalman 필터를 이용한 야외 환경에서 주행 로봇의 위치 추정 및 지도 작성)

  • Yoon Suk-June;Choi Hyun-Do;Park Sung-Kee;Kim Soo-Hyun;Kwak Yoon-Keun
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.6
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    • pp.585-593
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    • 2006
  • In this paper, we propose a vision-based simultaneous localization and map-building (SLAM) algorithm. SLAM problem asks the location of mobile robot in the unknown environments. Therefore, this problem is one of the most important processes of mobile robots in the outdoor operation. To solve this problem, Extended Kalman filter (EKF) is widely used. However, this filter requires computational power (${\sim}O(N)$, N is the dimension of state vector). To reduce the computational complexity, we applied compressed extended Kalman filter (CEKF) to stereo image sequence. Moreover, because the mobile robots operate in the outdoor environments, we should estimate full d.o.f.s of mobile robot. To evaluate proposed SLAM algorithm, we performed the outdoor experiments. The experiment was performed by using new wheeled type mobile robot, Robhaz-6W. The performance results of CEKF SLAM are presented.

Path Planning Algorithm for UGVs Based on the Edge Detecting and Limit-cycle Navigation Method (Limit-cycle 항법과 모서리 검출을 기반으로 하는 UGV를 위한 계획 경로 알고리즘)

  • Lim, Yun-Won;Jeong, Jin-Su;An, Jin-Ung;Kim, Dong-Han
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.5
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    • pp.471-478
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    • 2011
  • This UGV (Unmanned Ground Vehicle) is not only widely used in various practical applications but is also currently being researched in many disciplines. In particular, obstacle avoidance is considered one of the most important technologies in the navigation of an unmanned vehicle. In this paper, we introduce a simple algorithm for path planning in order to reach a destination while avoiding a polygonal-shaped static obstacle. To effectively avoid such an obstacle, a path planned near the obstacle is much shorter than a path planned far from the obstacle, on the condition that both paths guarantee that the robot will not collide with the obstacle. So, to generate a path near the obstacle, we have developed an algorithm that combines an edge detection method and a limit-cycle navigation method. The edge detection method, based on Hough Transform and IR sensors, finds an obstacle's edge, and the limit-cycle navigation method generates a path that is smooth enough to reach a detected obstacle's edge. And we proposed novel algorithm to solve local minima using the virtual wall in the local vision. Finally, we verify performances of the proposed algorithm through simulations and experiments.

Development of Processing System for Audio-vision System Based on Auditory Input (청각을 이용한 시각 재현 시스템의 개발)

  • Kim, Jung-Hun;Kim, Deok-Kyu;Won, Chul-Ho;Lee, Jong-Min;Lee, Hee-Jung;Lee, Na-Hee;Yoon, Su-Young
    • Journal of Biomedical Engineering Research
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    • v.33 no.1
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    • pp.25-31
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    • 2012
  • The audio vision system was developed for visually impaired people and usability was verified. In this study ten normal volunteers were included in the subject group and their mean age was 28.8 years old. Male and female ratio was 7:3. The usability of audio vision system was verified by as follows. First, volunteers learned distance of obstacles and up-down discrimination. After learning of audio vision system, indoor and outdoor walking examination was performed. The test was scored by ability of up-down and lateral discrimination, distance recognition and walking without collision. Each parameter was scored by 1 to 5. The results were 93.5 +- SD(ranges, 86 to 100) of 100. In this study, we could convert visual information to auditory information by audio-vision system and verified possibility of applying to daily life for visually impaired people.

Combining Object Detection and Hand Gesture Recognition for Automatic Lighting System Control

  • Pham, Giao N.;Nguyen, Phong H.;Kwon, Ki-Ryong
    • Journal of Multimedia Information System
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    • v.6 no.4
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    • pp.329-332
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    • 2019
  • Recently, smart lighting systems are the combination between sensors and lights. These systems turn on/off and adjust the brightness of lights based on the motion of object and the brightness of environment. These systems are often applied in places such as buildings, rooms, garages and parking lot. However, these lighting systems are controlled by lighting sensors, motion sensors based on illumination environment and motion detection. In this paper, we propose an automatic lighting control system using one single camera for buildings, rooms and garages. The proposed system is one integration the results of digital image processing as motion detection, hand gesture detection to control and dim the lighting system. The experimental results showed that the proposed system work very well and could consider to apply for automatic lighting spaces.

Development of A Lane Departure Monitoring and Control System

  • Huh Kunsoo;Hong Daegun;Stein Jeffrey L.
    • Journal of Mechanical Science and Technology
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    • v.19 no.11
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    • pp.1998-2006
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    • 2005
  • The lane departure avoidance systems have been considered promising to assist human drivers in AVCS (Advanced Vehicle Control System). In this paper, a lane departure monitoring and control system is developed and evaluated in the hardware-in-the-loop simulations. This system consists of lane sensing, lane departure monitoring and active steering control subsystems. The road image is obtained based on a vision sensor and the lane parameters are estimated using image processing and Kalman Filter technique. The active steering controller for avoiding the lane departure is designed based on the lane departure metric. The proposed lane departure avoidance system is realized in a steering HILS (hardware-in-the-loop simulation) tool and its performance is evaluated with a driver in the loop.

Developement and control of a sensor based quadruped walking robot

  • Bien, Zeungnam;Lee, Yun-Jung;Suh, Il-Hong;Lee, Ji-Hong
    • 제어로봇시스템학회:학술대회논문집
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    • 1990.10b
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    • pp.1087-1092
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    • 1990
  • This paper describes the development and control of a quadruped walking robot, named as KAISER-II. The control system with multiprocessor based hierachical structure is developed. In order to navigate autonomously on a rough terrain, an identification algorithm for robot's position is proposed using 3-D vision and guide-mark pattern Also, a simple attitude control algorithm is included using force sensors. Through experimental results, it is shown that the robot can not only walk statically on even terrain but also cross over or go through the artificially made obstacles such as stairs, horizontal bar and tunnel-typed one.

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3D Feature Based Tracking using SVM

  • Kim, Se-Hoon;Choi, Seung-Joon;Kim, Sung-Jin;Won, Sang-Chul
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.1458-1463
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    • 2004
  • Tracking is one of the most important pre-required task for many application such as human-computer interaction through gesture and face recognition, motion analysis, visual servoing, augment reality, industrial assembly and robot obstacle avoidance. Recently, 3D information of object is required in realtime for many aforementioned applications. 3D tracking is difficult problem to solve because during the image formation process of the camera, explicit 3D information about objects in the scene is lost. Recently, many vision system use stereo camera especially for 3D tracking. The 3D feature based tracking(3DFBT) which is on of the 3D tracking system using stereo vision have many advantage compare to other tracking methods. If we assumed the correspondence problem which is one of the subproblem of 3DFBT is solved, the accuracy of tracking depends on the accuracy of camera calibration. However, The existing calibration method based on accurate camera model so that modelling error and weakness to lens distortion are embedded. Therefore, this thesis proposes 3D feature based tracking method using SVM which is used to solve reconstruction problem.

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