• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.81-81
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• 2000

We use camera to apply human vision system in measurement. To do that, we need to know about camera parameters. The camera parameters are consisted of internal parameters and external parameters. we can fix scale factor&focal length in internal parameters, we can acquire external parameters. And we want to use these parameters in automatically driven vehicle by using camera. When we observe an camera parameters in respect with that the external parameters are important parameters. We can acquire external parameter as fixing focal length&scale factor. To get lane coordinate in image, we propose a lane detection filter. After searching lanes, we can seek vanishing point. And then y-axis seek y-sxis rotation component(${\beta}$). By using these parameter, we can find x-axis translation component(Xo). Before we make stepping motor rotate to be y-axis rotation component(${\beta}$), '0', we estimate image coordinates of lane at (t+1). Using this point, we apply this system to Kalman filter. And then we calculate to new parameters whick make minimum error.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.2
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• pp.164-171
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• 2010

We have studied the port-automation system which is requested by the steep increment of cost and complexity for processing the freight. This paper will introduce a new algorithm for navigating and controlling the autonomous Guided Vehicle (AGV). The camera has the optical distortion in nature and is sensitive to the external ray, the weather, and the shadow, but it is very cheap and flexible to make and construct the automation system for the port. So we tried to apply to the AGV for detecting and tracking the lane using the CCD camera. In order to make the error stable and exact, this paper proposes new concept and algorithm for obtaining the error is generated by the Virtual Photo-Sensor Array (VPSA). VPSAs are implemented by programming and very easy to use for the various autonomous systems. Because the load of the computation is light, the AGV utilizes the maximal performance of the CCD camera and enables the CPU to take multi-tasks. We experimented on the proposed algorithm using the mobile robot and confirmed the stable and exact performance for tracking the lane.

• Spatial Information Research
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• v.16 no.4
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• pp.455-465
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• 2008

Augmented reality (AR) has tremendous potential in visualizing geospatial information, especially on the actual physical scenes. However, to utilize augmented reality in mobile system, many researches have undergone with GPS or ubiquitous marker based approaches. Although there are several papers written with vision based markerless tracking, previous approaches provide fairly good results only in largely under "controlled environments." Localization and tracking of current position become more complex problem when it is used in indoor environments. Many proposed Radio Frequency (RF) based tracking and localization. However, it does cause deployment problems of large RF-based sensors and readers. In this paper, we present a noble markerless AR approach for indoor (possible outdoor, too) navigation system only using monoSLAM (Monocular Simultaneous Localization and Map building) algorithm to full-fill our grand effort to develop mobile seamless indoor/outdoor u-GIS system. The paper briefly explains the basic SLAM algorithm, then the implementation of our system.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.932-937
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• 2003

In this paper, we will explain about the unmanned vehicle control and modeling for combined obstacle avoidance and lane tracking. First, obstacle avoidance is considered as one of the important technologies in the unmanned vehicle. It is consisted by two parts: the first part includes the longitudinal control system for the acceleration and deceleration and the second part is the lateral control system for the steering control. Each system uses to the obstacle avoidance during the vehicle moving. Therefore, we propose the method of vehicle control, modeling and obstacle avoidance. Second, we describe a method of lane tracking by means of vision system. It is important in the unmanned vehicle and mobile robot system. In this paper, we deal with lane tracking and image processing method and it is including lane detection method, image processing algorithm and filtering method.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.12
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• pp.1027-1038
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• 2005

Object recognition in the field of robotics generally has depended on a computer vision system. Recently, RFID(Radio Frequency IDentification) has been suggested as technology that supports object recognition. This paper, introduces the advanced RFID-based recognition using a novel tag which is named a 3D tag. The 3D tag was designed to facilitate object recognition. The proposed RFID system not only detects the existence of an object, but also estimates the orientation and position of the object. These characteristics allow the robot to reduce considerably its dependence on other sensors for object recognition. In this paper, we analyze the characteristics of the 3D tag-based RFID system. In addition, the estimation methods of position and orientation using the system are discussed.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.323-324
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• 2007

본 논문은 네트워크을 통한 원격제어 시스템을 구축하는 연구로써 무선 랜과 AP를 이용하여 독립 무선 네트워크를 구축하고, 이동로봇의 주변 환경에 대한 레이저 센서정보와 영상정보를 전송한다. 그리고 스테레오 카메라와 Head Mounted Display를 사용하여 원격지에서 입체감 있는 영상을 보며 조작을 할 수 있게 하였으며, Head Motion Tracking를 이용해 이동로봇의 카메라를 별도의 조작 없이 컨트롤 가능하도록 방법을 제안하였다.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.3
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• pp.263-268
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• 2010

Purpose: Eye movements and fixation ability are an important procedure to obtain external information and essential means of clear vision. The purpose of this study was to determine the reading performance such as reading time and number of fixations when random text was viewed at varying distances. Methods: Twenty two presbyopes were participated. All subjects were screened for their suitability to participate in the study by clinical examination, and none of the participants had previously worn contact lenses and no previous experience of wearing any types of presbyopic vision correction except single vision. The reading time and number of fixations were recorded using eye tracker while each subjects was waring four vision corrections which included single vision for distance (SV), bifocal spectacle lenses (BIF), progressive addition lenses (PAL), and monovision (MV). The reading material was presented at distance and near distance. Results: Reading time and number of fixations for near stimulus were significantly different among vision correction used in this study (p<0.001). In particular, wearing SV required longer reading time and produced longer fixation duration for near text. However, reading distance text was similarity performed across vision corrections tested and there was no statistical difference found for either reading time and number of fixations. Conclusions: Wearing presbyopic vision correction is advantageous for reading task of near stimuli, but not having near correction such as wearing SV could result in longer reading time and higher number of fixation due to lacks of accommodative ability for near task. For the future studies, it would be interesting to examine the performance of reading both at adapted and unadapted stages as examining only unadapted wearers was limitation of this study.

• Journal of Korea Multimedia Society
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• v.9 no.5
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• pp.658-670
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• 2006

As the educational media tends to be more digitalized and individualized, the learning paradigm is dramatically changing into e-learning. Existing on-line courseware gives a learner more chances to learn when they are home with their own PCs. However, it is of little use when they are away from their digital media. Also, it is very labor-intensive to convert the original off-line contents to on-line contents. This paper proposes education mobile contents(EMC) that can supply the learners with dynamic interactions using various multimedia information by recognizing real images of off-line contents using mobile devices. Content-based image retrieval based on object shapes is used to recognize the real image, and shapes are represented by differential chain code with estimated new starting points to obtain rotation-invariant representation, which is fitted to computational resources of mobile devices with low resolution camera. Moreover we use a dynamic time warping method to recognize the object shape, which compensates scale variations of an object. The EMC can provide learners with quick and accurate on-line contents on off-line ones using mobile devices without limitations of space.

• Journal of the Korean Institute of Intelligent Systems
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• v.13 no.1
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• pp.51-56
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• 2003

The main goal of existing mobile robot system was a complete autonomous navigation and the vision information was just used as an assistant way such as monitoring For this reason, the researches have been going towards sophistication of autonomousness gradually and the production costs also has been risen. However, it is also important to control remotely an inexpensive mobile robot system which has no intelligence at all. Such systems may be much more effective than fully autonomous systems in practice. Visual information from a simple camera and distance information from ultrasonic sensors are used for this system. Collision avoidance becomes the most important problem for this system. In this paper, we developed a force feedback joystick to control the robot system remotely with collision avoiding capability. Fuzzy logic is used for the algorithm in order to implement the expert s knowledge intelligently. Some experimental results show the force feedback joystick werks very well.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1024-1027
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• 2005

This paper describes the performance index of mobile robot and development of testbed which is used to evaluate the index. The developed testbed has rectangular structure similar to a living room of home. It is semi-automation testbed system for evaluation of cleaning performance index. This system is composed with scattering and cleaning equipment of test materials, equipment rifting of objects in inner space and sides itself, vision processing system. To be consistent of performance evaluation of cleaning robot, we make use of camera in this system for the sake of measurement of robot s mobility, path and suction quantity.