• Journal of IKEEE
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• v.18 no.4
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• pp.636-644
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• 2014

This paper is to technically implement the sensing platform for Home-Wellness Robot. First, self-localization technique is based on a smart home and object in a home environment, and IOT(Internet of Thing) between Home Wellness Robots. RF tag is set in a smart home and the absolute coordinate information is acquired by a object included RF reader. Then bluetooth communication between object and home wellness robot provides the absolute coordinate information to home wellness robot. After that, the relative coordinate of home wellness robot is found and self-localization through a stereo camera in a home wellness robot. Second, this paper proposed fuzzy control methode based on a vision sensor for approach object of home wellness robot. Based on a stereo camera equipped with face of home wellness robot, depth information to the object is extracted. Then figure out the angle difference between the object and home wellness robot by calculating a warped angle based on the center of the image. The obtained information is written Look-Up table and makes the attitude control for approaching object. Through the experimental with home wellness robot and the smart home environment, confirm performance about the proposed self-localization and posture control method respectively.

• Journal of Navigation and Port Research
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• v.26 no.1
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• pp.146-151
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• 2002

Efficiency of dredging work depends on the types of equipment used, the sediments encountered, whether the work to be performed is new or for maintenance, pre and/or post hydrographic surveying and so forth. Among those, surveying accuracy which is directly determined by the control of the dredge's position and depth surveying accuracy being surveyed at the dredging point are important factors. The purpose of this study is to develop an integrated process management system for pump dredge. The system is composed of 4 sub-systems such as LADGPS for dredge positioning dredging point determination, tidal gauge and angular depth sensor for depth determination, and GIS and ENC process management. The process management system for pump dredge developed was installed on the pump dredge "EUNJIN PD-2" but is now producing work data for comparison with performance of the existing dredge. The data retrieved from the pump dredge process management system up to now shows similar result from the grab dredge management system which was developed previously. It is easy to operate, achieves good accuracy with only 45cm unevenness, reduces working perioa by 20 percint,. More precise evaluation of the system comes later after the dredging work is completed.completed.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11b
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• pp.472-479
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• 2000

A persimmon harvesting vehicle that can be operated in hilly orchards as well as a manipulator that can be used to harvest persimmons located in remote positions in the trees were designed and developed. The vehicle could be operated with keeping balanced position in an inclined field and its working platform could be moved up and down easy to approach fruits in a remote region with the aids of a hydraulic and a electrical and electronics systems. The weight of the vehicle was 927 kg and the center of gravity was located at 427 mm to the inner side from the center of a right driving caterpillar, 607 mm to a rear axle from the center of a front axle, and 562 mm to upward from ground. The automatic level control sensor for leveling the working platform was activated within 14.5 ∼ 16.5 degrees of slope variation. The total length of the manipulator was 1.39 m and weight is 975 g. It was powered by a 12 V geared motor to detach persimmon fruits with a rotational force. The gripper was made of plastic and rubber to increase a frictional force. In a performance evaluation test, static tipping angle, dynamic tipping angle toward front side when the vehicle was moving downward, climbing angle, driving speed of the vehicle were measured or calculated. In persimmon harvesting tests 24.9% of yield was increased by hand picking with the aid of the vehicle and additional 7% of yield were increased when the manipulator was used. Therefore, 99010 of total possible yield was achievable when both of the vehicle and the manipulator were used for the manual persimmon harvesting. Increase in 22.5% of total yield was achieved with the manipulator only.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.10
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• pp.902-909
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• 2015

In this paper, monovision based relative navigation for a satellite proximity operation is studied. The chaser satellite only uses one camera sensor to observe the target satellite and conducts image tracking to obtain the target pose information. However, by using only mono-vision, it is hard to get the depth information which is related to the relative distance to the target. In order to resolve the well-known difficulty in computing the depth information with the use of a single camera, the active contour method is adopted for the image tracking process. The active contour method provides the size of target image, which can be utilized to indirectly calculate the relative distance between the chaser and the target. 3D virtual reality is used in order to model the space environment where two satellites make relative motion and produce the virtual camera images. The unscented Kalman filter is used for the chaser satellite to estimate the relative position of the target in the process of glideslope approaching. Closed-loop simulations are conducted to analyze the performance of the relative navigation with the active contour method.

• Journal of the Institute of Convergence Signal Processing
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• v.20 no.4
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• pp.245-251
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• 2019

Sonar bearing accuracy is the correspondence between the target orientation predicted by sonar and actual target orientation, and is obtained from measurements. However, when measuring sonar bearing accuracy, many errors are included in the results because they are made at sea, where complex and diverse environmental factors are applied. In particular, parallax error caused by the difference between the position of the GPS receiver and the sonar sensor, and the time delay error generated between the speed of underwater sound waves and the speed of electromagnetic waves in the air have a great influence on the accuracy. Correcting these parallax errors and time delay errors without an automated tool is a laborious task. Therefore, in this study, we propose a sonar bearing accuracy measurement equipment with parallax error and time delay error correction. The tests were carried out through simulation data and real data. As a result of the test it was confirmed that the parallax error and time delay error were systematically corrected so that 51.7% for simulation data and more than 18.5% for real data. The proposed method is expected to improve the efficiency and accuracy of sonar system detection performance verification in the future.

• Spatial Information Research
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• v.21 no.4
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• pp.63-70
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• 2013

With the increasing use of high-performance mobile devices such as smartphones, users have been able to connect to the Internet anywhere, anytime, so that Location Based Services(LBSes) have been popular among the users in order to obtain personalized information associated with their locations. The services have advanced to provide the information realistically and intuitively by adopting Augmented Reality(AR) technology, where the technology utilizes various sensors embedded in the mobile devices. However, the services have inherent problems due to the small screen size of the mobile devices and the complexity of the real world environment. Overlapping contents on a small screen and user's possible movement should be taken into consideration in displaying the icons on objects that block user's environment such as trees and buildings. The problems mainly happen when the services use only user's location and sensor data to calculate the position of the displayed information. In order to solve the problems, this paper proposes a method that applies street data extracted from a digital map. The method uses the street data as well as the location and direction data to determine contents that are placed on both sides of a virtual street which augments the real street. With scrolling the virtual street, which means a virtual movement, some information far away from the location of the user can be identified without user's actual movement. Also the proposed method is implemented for region "Aenigol", and the efficiency and usefulness of the method is verified.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.5
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• pp.162-177
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• 2020

The perception of traffic environment based on various sensors in autonomous driving system has a direct relationship with driving safety. Recently, as the perception model based on deep neural network is used due to the development of machine learning/in-depth neural network technology, a the perception model training and high quality of a training dataset are required. However, there are several realistic difficulties to collect data on all situations that may occur in self-driving. The performance of the perception model may be deteriorated due to the difference between the overseas and domestic traffic environments, and data on bad weather where the sensors can not operate normally can not guarantee the qualitative part. Therefore, it is necessary to build a virtual road environment in the simulator rather than the actual road to collect the traning data. In this paper, a training dataset collection process is suggested by diversifying the weather, illumination, sensor position, type and counts of vehicles in the simulator environment that simulates the domestic road situation according to the domestic situation. In order to achieve better performance, the authors changed the domain of image to be closer to due diligence and diversified. And the performance evaluation was conducted on the test data collected in the actual road environment, and the performance was similar to that of the model learned only by the actual environmental data.

• Journal of the Earthquake Engineering Society of Korea
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• v.13 no.3
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• pp.11-19
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• 2009

Recently, concerns relating to the maintenance of large structures have been increased. In addition, the number of large structures that need to be evaluated for their structural safety due to natural disasters and structural deterioration has been rapidly increasing. It is common for the structural characteristics of an older large structure to differ from the characteristics in the initial design stage, and changes in dynamic characteristics may result from a reduction in stiffness due to cracks on the materials. The process of deterioration of such structures enables the detection of damaged locations, as well as a quantitative evaluation. One of the typical measuring instruments used for the monitoring of bridges and buildings is the dynamic measurement system. Conventional dynamic measurement systems require considerable cabling to facilitate a direct connection between sensor and DAQ logger. For this reason, a method of measuring structural responses from a remote distance without the mounted sensors is needed. In terms of non-contact methods that are applicable to dynamic response measurement, the methods using the doppler effect of a laser or a GPS are commonly used. However, such methods could not be generally applied to bridge structures because of their costs and inaccuracies. Alternatively, a method using a visual image can be economical as well as feasible for measuring vibration signals of inaccessible bridge structures and extracting their dynamic characteristics. Many studies have been conducted using camera visual signals instead of conventional mounted sensors. However, these studies have been focused on measuring displacement response by an image processing technique after recording a position of the target mounted on the structure, in which the number of measurement targets may be limited. Therefore, in this study, a model experiment was carried out to verify the measurement algorithm for measuring multi-point displacement responses by using a DIC (Digital Image Correlation) technique.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.2
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• pp.84-91
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• 2009

This paper presents an online partial 3D modeling methodology that uses a mobile augmented reality system and aerial photographs, and a tracking methodology that compares the 3D model with a video image. Instead of relying on models which are created in advance, the system generates a 3D model for a real building on the fly by combining frontal and aerial views. A user's initial pose is estimated using an aerial photograph, which is retrieved from a database according to the user's GPS coordinates, and an inertial sensor which measures pitch. We detect edges of the rooftop based on Graph cut, and find edges and a corner of the bottom by minimizing the proposed cost function. To track the user's position and orientation in real-time, feature-based tracking is carried out based on salient points on the edges and the sides of a building the user is keeping in view. We implemented camera pose estimators using both a least squares estimator and an unscented Kalman filter (UKF). We evaluated the speed and accuracy of both approaches, and we demonstrated the usefulness of our computations as important building blocks for an Anywhere Augmentation scenario.

• Journal of Oral Medicine and Pain
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• v.31 no.4
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• pp.365-373
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• 2006

This study suggested correction of excessive mouth opening or maximum occlusal contact to analyse occlusal contact time, occlusal contact number and force through evaluation of occlusal pattern in policemen with temporomandibular disorders. The community of policemen influence on temporomandibular disorder's development and progress due to other condition of mouth opening and maximal occlusal contact. Repeated training or changes of usual life style may cause imbalance of stomatognathic system including the masticatory muscle, then develop or aggravate pain of temporomandibular joints and associated structures. This study uses T-scan II system(Tekscan Co., USA) for evaluation on occlusal pattern may influence temporomandibular disorders, and then the subjects take a sensor at 20 mm opening for maximal occlusal contact force. The policemen with temporomandibualr disorders get more long time on maximum contact timing, more short on end contact timing, and more force on end contact force than general society's. So they get closure of mouth with more short time and more force, then transfer remaining load to temporomandibular joint. There are no statistically significances between affected side and occlusal pattern of occlusal contact time and force. There are Left -right dental arch imbalances seems on Rt. dental arch if affected side is right and Lt. dental arch if affected side is left. In above results, It's worth due consideration that policemen with temporomandibular disorders get more smooth mandibualr movement and less force on maximal occlusal contact position.