• International Journal of Control, Automation, and Systems
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• 제5권6호
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• pp.681-690
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• 2007

This article presents the kinematic analysis and implementation of an interface and control of two robots-an exoskeleton master robot and a human-like slave robot with two arms. Two robots are designed and built to be used for motion-following tasks. The operator wears the exoskeleton master robot to generate motions, and the slave robot is required to follow after the motion of the master robot. To synchronize the motions of two robots, kinematic analysis is performed to correct the kinematic mismatch between two robots. Hardware implementation of interface and control is done to test motion-following tasks. Experiments are performed to confirm the feasibility of the motion-following tasks by two robots.

• 대한조선학회논문집
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• 제47권4호
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• pp.496-507
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• 2010

It is well known that when a high-speed planing craft travels in following seas it experiences long-periodic motions due to low encounter frequency, and it often loses its course keeping stability. Therefore, it is necessary to study the sea-keeping performance and stability of it in the following seas. In this paper, the vertical motions of a planing craft were measured in following regular waves, and the test results were compared with the theoretical results. In the case of the same encounter frequency, non-dimensionalized motion amplitudes become larger as Froude number is higher, and non-dimensionalized motion amplitudes in head waves are larger than those in following waves. The mean values of the motions in following waves are similar to the running attitudes of a craft in calm water at the same Froude number.

• 제어로봇시스템학회논문지
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• 제9권12호
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• pp.994-1000
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• 2003

A new relative motion control methodology for a following system to an independent leading system is proposed for controlling relative position, velocity, and tension etc. It is based on maintaining minimum relative error between two independent systems. The control command of the following system to a leading system is generated by adding the current command and the output of the relative error compensation. The proposed control method is implemented on the experimental equipment which is a wire winding-unwinding system to control the tension of the line. The results show the unwinding system(follower) following the independent motion of the winding system(leader) to control the constant tension of the line in order to keep the roller dancer in reference position. The relative motion control method proposed in this paper can be applied to high precision equipment for unwinding and winding fine wire, fine fiber, and tape etc.

• 제어로봇시스템학회논문지
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• 제6권7호
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• pp.586-593
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• 2000

In this paper we propose a new approach to the autonomous wall-following of wheeled mobile robots using hybrid system reference motion synthesis and generation. The hybrid system approach is in-troduced to the motion control of nonholonomic mobile robots for the indoor navigation problems. In the dis-crete event system the discrete states are defined by the user-defined constraints and the reference mo-tion commands are specified in the abstracted motions. The hybrid control system applied for the non-holonomic mobile robots can combine the motion planning and autonomous navigation with obstacle avoid-ance for the indoor navigation problem. Simulation results show that hybrid system approach is an effective method for the autonomous navigation in indoor environments.

• 자동차안전학회지
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• 제11권3호
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• pp.30-36
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• 2019

This paper suggests a car-following algorithm for urban environment, with multiple target candidates. Until now, advanced driver assistant systems (ADASs) and self-driving technologies have been researched to cope with diverse possible scenarios. Among them, car-following driving has been formed the groundwork of autonomous vehicle for its integrity and flexibility to other modes such as smart cruise system (SCC) and platooning. Although the field has a rich history, most researches has been focused on the shape of target trajectory, such as the order of interpolated polynomial, in simple single-lane situation. However, to introduce the car-following mode in urban environment, realistic situation should be reflected: multi-lane road, target's unstable driving tendency, obstacles. Therefore, the suggested car-following system includes both in-lane preceding vehicle and other factors such as side-lane targets. The algorithm is comprised of three parts: path candidate generation and optimal trajectory selection. In the first part, initial guesses of desired paths are calculated as polynomial function connecting host vehicle's state and vicinal vehicle's predicted future states. In the second part, final target trajectory is selected using quadratic cost function reflecting safeness, control input efficiency, and initial objective such as velocity. Finally, adjusted path and control input are calculated using model predictive control (MPC). The suggested algorithm's performance is verified using off-line simulation using Matlab; the results shows reasonable car-following motion planning.

• 한국의류산업학회지
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• 제4권2호
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• pp.145-155
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• 2002

In order to investigate how upper limb motion gives influence on clothing, this study measured tests by following standards: Front Vertical motion, Side-Vertical motion, and Horizontal motion. For this study, the procedures in the order of alphabet are applied. A. Eeach of testee's pattern was copied by the motion with a method of tight fitting technique. B. Analyzing each of the size-change on measuring item. C. Studying the moving aspects at each datum points. The results shows that the biggest change can be found in the following items. 1) In vertical motion of F4 (the length to shoulder point from A-point) 2) In horizontal motion of F5 (the length to front-width point from A-point), the check-result gained by checking the notice between motions shows that the most noticeable items are F4 (the length to shoulder point from A-point), F5 (the length to front-width point from A-point), F6 (the length to armpit point from A-point), B7 (the length to side-waist point from B-point). In result of the study of datum point's movement by motion, the items which were measured with the longest on straight-distance in vertical motion are the front and rear-shoulder, and the rear-shoulder, front-armpit in horizontal motion each. In the movement of each datum points by length, the check-result gained by checking the notice between motions shows that the most remarkable item is the front-shoulder.

• 제어로봇시스템학회논문지
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• 제12권2호
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• pp.101-105
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• 2006

Disk radial runout creates a periodic relative motion between the laser beam spot and tracks formed on an optical disk. While only focus control is activated, the periodic relative motion yields sinusoid-like waves in the tracking error signal, where one cycle of the sinusoid-like waves corresponds to one track. The frequency of the sinusoid-like waves varies depending on the disk rotational speed and the amount of the disk radial runout. If the frequency of the tracking error signal in the off-track state is too high due to large radial runout of the disk, it is not a simple matter to begin track-following control stably. It might take a long time to reach a steady state or tracking control might fail to reach a stable steady state in the worst case. This article proposes a simple method for reducing the relative motion caused by the disk radial runout in the off-track state. The relative motion in the off-track state is effectively reduced by a drive input obtained through measurements of the tracking error signal and simple calculations based on the measurements, which helps reduce the transient response time of the track-following control. The validity of the proposed method is verified through an experiment using an optical disk drive.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1621-1624
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• 2003

This paper presents a new method that generates a path that has no collision with the obstacles or the characters by using the three motion parameters, and automatically creates natural motions of characters that are confined to the path. Our method consists of three parameters: the joint information parameter, the behavior information parameter, and the environment information parameter. The joint information parameters are extracted from the joint angle data of the character and this information is used when creating a path following motion by finding the relation-function of the parameters on each joint. A user can set the behavior information parameter such as velocity, status, and preference and this information is used for creating different paths, motions, and collision avoidance patterns. A user can create the virtual environment such as road and obstacle, also. The environment is stored as environment information parameters to be used later in generating a path without collision. The path is generated using Hermit-curve and each control point is set at important places.

• Physical Therapy Rehabilitation Science
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• 제10권4호
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• pp.463-469
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• 2021

Objective: If non-surgical treatment fails, arthroscopic rotator cuff repair (ARCR) is recommended, and ARCR considers graft augmentation in consideration of size, direction, and re-tear. It is reported to have potential benefits by improving the healing rate as it can fill the gaps that have been left behind. The purpose of this study is to investigate the effect of structural changes observed after ARCR on muscle action through magnetic resonance imaging and to investigate the effect of appropriate physical therapy required for graft augmentation in the general ARCR rehabilitation protocol. Case presentation: A 47-year-old male hospitalized for postoperative rehabilitation following ARCR participated in a 5-week physical therapy intervention. The postoperative day was 6 months, but due to shooting pain and shoulder dysfunction,and the movement of the shoulder was compensatory motion, not normal motion. Physical agents, manual therapy, and supervised exercise for 110 minutes per session were performed 3 times a week, and pain intensity, range of motion, function, and strength were evaluated. Results: As a result of the study, the patient showed positive improvement in pain intensity, range of motion, function, and strength. In addition, normal scapulohumeral rhythm movement was observed. Conclusions: According to the results of this case, appropriate physical therapy according to the compensatory motion shown in the structural changes after ARCR can positively improve the pain intensity, range of motion, function, and strength of ARCR patients.

• 한국정밀공학회지
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• 제14권7호
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• pp.15-21
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• 1997

This paper presented a linear motion accuracy by using two-dimensional probe with the master block and the square for NC machine tools. This measuring system could be measured motion error due to numerical control system. The results of measurement and simulation for motion error were similar, and so, this system had enough accuracy to measure a linear motion accuracy for NC machine tools. The experimental results are as follows. 1. This measuring system could be measured motion error due to mumerical control system. 2. The results of measurement and simulation for motion error were similar. 3. This measuring system had enough accuracy to measure a linear motion accuracy for NC machine tools.