• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.10
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• pp.1915-1923
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• 2011

For automated guidance control of a magnetically guided-all wheel steered vehicle, it is necessary to have information about position and orientation of the vehicle, and deviations from the reference path in real time. The magnet reference system considered here consists of three magnetic sensors mounted on the vehicle and magnetic markers, which are non-equidistantly buried in the road. This paper presents an observer to estimate such position and orientation at the center of gravity of the vehicle. This algorithm is based on the simple kinematic model of vehicle and uses the data of wheel velocity, steering angle, and the discrete measurements of marker positions. Since this algorithm requires the exact values of initial states, we have also proposed an algorithm of determining the initial position and orientation from the 16 successive magnet pole data, which are given by the magnetic measurement system(MMS). The proposed algorithm is capable of continuing to estimate for the case that the magnetic sensor fail to measure up to three successive magnets. It is shown through experimental data that the proposed algorithm works well within permissible error range.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.1
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• pp.132-138
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• 2014

The use of AGVs(Automated Guided Vehicles) are increasing in many factories. The most widely used AGV system is that magnetic tapes are attached on the factory floor to make guided path and an AGV equipped with a magnetic sensor follows the path by sensing magnetic flux. In this AGV system, usually a magnetic sensor is attached on the front end of an AGV to detect the guided path and the sensor generates analog voltages proportional to the magnetic flux. The problem is that the AGV in use has rather big tracking errors because the accurate orientation of the AGV can not be detected by using only one magnetic sensor. In this paper, we propose a method to minimize the path tracking errors. In our method, one additional sensor is attached on the rear end of the AGV to estimate the orientation of the AGV and to control more accurately the AGV according to the estimated orientation of the AGV. We performed several experiments and the results successfully show the feasibility of the proposed method.

• Journal of Navigation and Port Research
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• v.37 no.3
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• pp.309-313
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• 2013

This paper is about a complex sensor system of an automatic guided vehicle(AGV) for loading and unloading payloads. For the AGV to approach to the target rack for loading and unloading the payload, a way to identify the position and orientation was studied. To identify the position and orientation of the AGV accurately, a complex sensor system composed of RFID, IMU, and limit sensors was developed, and the performance of each sensor was undertaken. A model AGV was constructed, and the good performance of the developed complex sensor system was verified through performance experiments.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.11
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• pp.3064-3082
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• 2023

During the last decade, several Electronic Orientation Aids devices have been proposed to solve the autonomy problems of visually impaired people. When hearing is considered the primary sense for Visually Impaired people (VI) and it is generally loaded with the environment, the use of tactile sense can be considered a solution to transmit directional information. This paper presents a new wearable haptic system based on four motors implemented in shoes, while six directions can be played. This study aims to introduce an interface design and investigate an appropriate means of spatial information delivery through haptic sense. The first experiment of the proposed system was performed with 15 users in an indoor environment. The results showed that the users were able to recognize, with high accuracy, the directions displayed on their feet. The second experiment was conducted in an outdoor environment with five blindfolded users who were guided along 120 meters. The users, guided only by the haptic system, successfully reached their destinations. The potential of tactile-foot stimulation to help VI understand Electronic Orientation Aids (EOA) instructions was discussed, and future challenges were defined.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.7
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• pp.3179-3183
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• 2014

Background: The purpose of study was to evaluate radiologic or clinical features of breast cancer undergoing ultrasound (US)-guided 14G core needle biopsy (CNB) and analyze the differences between underestimated and accurately diagnosed groups. Materials and Methods: Of 1,898 cases of US-guided 14G CNB in our institute, 233 cases were proven to be cancer by surgical pathology. The pathologic results from CNB were invasive ductal carcinoma (IDC) (n=157), ductal carcinoma in situ (DCIS) (n=40), high-risk lesions in 22 cases, and benign in 14 cases. Among high-risk lesions, 7 cases of atypical ductal hyperplasia (ADH) were reported as cancer and 11 cases of DCIS were proven IDC in surgical pathology. Some 29 DCIS cases and 157 cases of IDC were correctly diagnosed with CNB. The clinical and imaging features between underestimated and accurately diagnosed breast cancers were compared. Results: Of 233 cancer cases, underestimation occurred in 18 lesions (7.7%). Among underestimated cancers, CNB proven ADH (n=2) and DCIS (n=11) were diagnosed as IDC and CNB proven ADH (n=5) were diagnosed at DCIS finally. Among the 186 accurately diagnosed group, the CNB results were IDC (n=157) and DCIS (n=29). Comparison of underestimated and accurately diagnosed groups for BI-RADS category, margin of mass on mammography and US and orientation of lesion on US revealed statistically significant differences. Conclusions: Underestimation of US-guided 14G CNB occurred in 7.7% of breast cancers. Between underestimated and correctly diagnosed groups, BI-RADS category, margin of the mass on mammography and margin and orientation of the lesions on US were different.

• Journal of Advanced Navigation Technology
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• v.25 no.4
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• pp.293-298
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• 2021

In general, the guided weapon seeker and the guided control device process the target, search, recognition, and capture information to indicate the state of the guided missile, and play a role in controlling the operation and control of the guided weapon. The signals required for guided weapons are gaze change rate, visual signal, and end-stage fuselage orientation signal. In order to process the complex and difficult-to-process missile signals of recent missiles in real time, it is necessary to increase the data processing speed of the missiles. This study showed the processing speed after applying the stop and go and inverse enumeration algorithm among the parallel algorithm methods of PINQ and comparing the processing speed of the signal data required for the guided missile in real time using the guided missile inspection program. Based on the derived data processing results, we propose an effective method for processing missile data when applying a parallel processing algorithm by comparing the processing speed of the multi-core processing method and the single-core processing method, and the CPU core utilization rate.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.1 s.94
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• pp.81-86
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• 2005

In this work, we propose a new ultrasonic damage inspection method in plate structures. The proposed method employs an OPMT(orientation-adjustable patch-type magnetostrictive transducer) in order to make the ultrasonic waves directed to a specific target point. For experiments, virtual grid points were set up at every 50 mm in an aluminum plate and two OPMTs were used for inspection. If there exists a crack in a plate, the reflected Lamb wave from the crack is measured in addition to the direct waves from the transmitting transducer to the receiving transducer.

• Journal of Biomedical Engineering Research
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• v.26 no.5
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• pp.265-270
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• 2005

A new Computer Integrated Surgical Robot system is composed of a surgical robot, a surgical planning system, and an optical tracking system. The system plays roles of an assisting surgeon and taking the place of surgeons for inserting a pedicle screw in spinal fusion. Compared to pure surgical navigation systems as well as conventional methods for spinal fusion, it is able to achieve better accuracy through compensating for the portending movement of the surgical target area. Furthermore, the robot can position and guide needles, drills, and other surgical instruments or conducts drilling/screwing directly. Preoperatively, the desired entry point, orientation, and depth of surgical tools for pedicle screw insertion are determined by the surgical planning system based on CT/MR images. Intra-operatively, position information on surgical instruments and targeted surgical areas is obtained from the navigation system. Two exemplary experiments employing the developed image-guided surgical robot system are conducted.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2000.11a
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• pp.219-225
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• 2000

The major movement block of the containers have range between apron and designation points on yard in container terminal. The yard tractor operated by human takes charge of its movement in conventional container terminal. In automated container terminal, AGV(Automated Guided Vehicle) has charge of the yard tractor's role and the navigation path is ordered from upper level control system. The automated container terminal facilities must have the docking system to guide landing line to have high speed travelling and precision positioning. The general method for docking system uses the vision system with CCD camera, infra red, and laser. This paper describes the detection of AGV's position and orientation using laser slit beam to develop docking system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.807-808
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• 2008

This is concerned with the radiation pattern of elastic waves in a plate generated by an orientation-adjustable patch-type magnetostrictive transducer. In general, not only the Lamb waves but also shear horizontal (SH) waves are produced by the deformation of the circular magnetostrictive patch bonded to a plate. Among the two types of waves, this paper investigates the radiation patterns of SH waves. A number of experimental results are presented. They are also accurately predicted by a theory developed by the present authors. Experimental findings were explained by a theoretical analysis.