• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 추계학술대회 논문집
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• pp.149-153
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• 2001

This paper presents an end-point control of 1-link flexible arm tip-mass by using fuzzy position control algorithm. The arm is mounted on a translational mechanism driven by a ballscrew, whose rotation is controlled by a DC servomotor. Tip position is controlled so that it follows a desired position. Feedback signal is composed of both tip displacement error and change of error. This paper gives tip responses according to the variations of tip-mass and beam length, and the effects of reducing the residual vibrations occurring at the end-point. In the case of the residual vibrations of tip displacement, fuzzy control has better results than the PD-control.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1997년도 춘계학술대회논문집
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• pp.281-285
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• 1997

We developed the system which could trace the hand and arm motion to test the product usability by integrating a wired-glove and a magnetic position sensing system. The magnetic position sensing system traces the position and orientation of the arm while the sired-glove measures 18 phal angeal joint angles. A case study was performed on two different camcorders in weight. The heavier camcorder was more stable than the lighter one. Also the recording task is more stable than the zoom-in and zoom-out tasks. This system could be used to monitor and quantify the hand and arm motion in real time and also could be used to test the product usability where the hand motion is important.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.896-901
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• 1990

A simulation analysis is presented for the position control of a single-link flexible manipulator whose end-effector is subjected to an impulsive force. Arm is rotated by a d.c. servomotor at the shoulder so that the end point stays precisely at its initial position even if the end effector is thumped with the impulsive loading. A gap sensor is used to measure the tip displacement. The control torque based on the PD control law is applied to the motor through the driver circuit. The control strategy is tested by means of computer simulation for the one-link flexible-arm prototype in the authers' laboratory at Tohoku Univ.

• 대한인간공학회지
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• 제18권1호
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• pp.55-69
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• 1999

It is very common to use the powered hand tools to enhance the productivity in various types of industry. But the use of the powered hand tools could cause health problems such as cumulative trauma disorders and vibration white fingers. In this study. the effects of hand-arm vibration and anatomical hand position on localized muscle fatigue were analyzed. Eight healthy male subjects volunteered for the study. Vibration frequencies of 0, 40, 80, 100, 150, and 200Hz and hand position of flexion and ulnar deviation were selected for the independent variables of the experiment. Median frequency shifting was used as a dependent variable. The results indicated that at the vibration frequency of 40Hz and accelation of 2g, the muscle fatigue was the greatest. For the hand position. there was significant difference between neutral and flexion. and neutral and ulnar deviation, but no difference between flexion and ulnar deviation. These results could be applied in designing powered hand tools to minimize the health problems.

• 로봇학회논문지
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• 제15권2호
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• pp.131-138
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• 2020

This paper proposes a low-cost robotic surgery system composed of a general purpose robotic arm, an interface for daVinci surgical robot tools and a modular haptic controller utilizing smart actuators. The 7 degree of freedom (DOF) haptic controller is suspended in the air using the gravity compensation, and the 3D position and orientation of the controller endpoint is calculated from the joint readings and the forward kinematics of the haptic controller. Then the joint angles for a general purpose robotic arm is calculated using the analytic inverse kinematics so that that the tooltip reaches the target position through a small incision. Finally, the surgical tool wrist joints angles are calculated to make the tooltip correctly face the desired orientation. The suggested system is implemented and validated using the physical UR5e robotic arm.

• 대한기계학회논문집
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• 제14권5호
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• pp.1112-1118
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• 1990

본 연구에서는 선단의 각속도를 측정하여 궤환함으로써 유연한 로봇팔의 진동 을 억제함과 동시에 선단의 위치를 제어하고자 한다. 선단에 레이트 자이로를 설치 하여 선단의 각속도를 측정하였다. 레이트 자이로는 이미 비행체의 제어에 널리 사 용되고 있는 정밀 각속도 센서로 소형이면서 가벼워 회전 진동측정이 매우 쉽고 편리 한 장점이 있다. 또한 유연한 로봇팔을 선단에 집중질량이 있는 오일러보로 가정하 여 모델링을 하였으며, 실험에서는 1차진동 모드까지만 고려하였다.

• Computational Structural Engineering : An International Journal
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• 제1권2호
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• pp.89-96
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• 2001

A study on the topology optimization of a Hard-Disk-Driver(HDD) actuator arm is presented. The purpose of the present wert is to increase the natural frequency of tole first lateral mode of the HDD actuator arm under the constraint of total moment of inertia, so as to facilitate the position control of the high speed actuator arm. The first lateral mode is an important factor in the position control process. Thus the topology optimization for 2-D model of the HDD actuator arm is considered. A new objective function corresponding to multieigenvalue optimization is suggested to improve the solution of the eigenvalue optimization problem. The material density of the structure is treated as the design variable and the intermediate density is penalized. The effects of different element types and material property functions on the final topology are studied. When the problem is discretized using 8-node element of a uniform density, tole smoothly-varying density field is obtained without checker-board patterns incurred. AS a result of 7he study, an improved design of the HDD actuator arm is suggested. Dynamic characteristics of the suggested design are compared computationally with those of the old design. With the same amount of the moment of inertia, the natural frequency of the first lateral mode of the suggested design is subsequently increased over the existing one.

• 대한물리의학회지
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• 제12권2호
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• pp.75-82
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• 2017

PURPOSE: The purpose of this study was to determine the effects of arm training in standing position on balance and walking ability in chronic stroke patients. METHODS: Sixteen chronic stroke patients were allocated equally and randomly to an experimental group (n=8) or a control group (n=8). All participants received 60 minutes of comprehensive rehabilitation treatment, the experimental group additionally received an arm training in standing position for 30 minutes, while the control group additionally performed a treadmill training for 30 minutes. These 30-minute training sessions were held three times per week for six weeks. Upper extremity function was assessed using Fugle-Meyer motor assessment function upper extremity (FMA-UE), balance was assessed using Berg balance scale (BBS), and walking ability (gait speed, cadence, step length, and double limb support period) was assessed using the GAITRite system. RESULTS: Improvement on all outcome measures was identified from pre-to-post intervention for both groups (p<.05). Post-intervention, there was a significant between-group difference on BBS, gait speed, cadence, step length, and double limp support period (p<.05). The experimental group exhibited greater improvement in the BBS (p=.01; z=-2.48), gait speed (p=.01; z=-3.26), cadence (p=.02; z=-2.31), step length (p=.01; z=-3.36), and double limb support period (p=.03; z=-2.84) compared to the control group. CONCLUSION: The findings of this study suggest that arm training in standing position may be beneficial for improving balance and walking ability of patients with chronic stroke.

• Industrial Engineering and Management Systems
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• 제3권1호
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• pp.78-84
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• 2004

To optimize movement of a multi-joint robot arm is known to be a difficult problem, because it is a kind of redundant system. Although the end-effector is set its position by each angle of the joints, the angle of each joint cannot be uniquely determined by the position of the end-effector. There exist the infinite number of different sets of joint angles which represent the same position of the end-effector. This paper describes how to manage the angle of each joint to move its end-effector preferably on an X-Y plane with obstacles in the end-effector’s reachable area, and how to optimize the movement of a multi-joint robot arm, evading obstacles. The definition of “preferable” movement depends upon a purpose of robot operation. First, we divide viewpoints of preference into two, 1) the standpoint of the end-effector, and 2) the standpoint of joints. Then, we define multiple objective functions, and formulate it into a multi-objective programming problem. Finally, we solve it using multi-purpose genetic algorithm, and obtain reasonable results. The method described here is possible to add appropriate objective function if necessary for the purpose.

• 대한견주관절학회:학술대회논문집
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• 대한견주관절학회 2008년도 제16차 학술대회
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• pp.164-164
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• 2008

The beach-chair traction position is designed to allow the use of traction while allowing the surgeon to orient the shoulder in an upright position and convert to an open procedure, if necessary. The patient is placed in the beach-chair position under general anesthesia. A three-point shoulder holder (Arthrex, Naples, Florida) is attached to the rail of the operating table on the same side as the surgeon, whereas it is placed on the side opposite the surgeon in the lateral decubitus position. A shoulder traction and rotation sleeve (Arthrex) are affixed to the arm following the manufacturer's instructions. Positioning the thumb toward the closed side of the sleeve ensures a field for the anterior portion of the rotator cuff and prevents the tendency of the suspension apparatus to place the arm in internal rotation. The arm is maintained in 30 to 40 degree abduction and 30 to 40 degree flexion by controlling the length and height of the bar and the location of the universal clamp. The universal clamp allows multiple planes of adjustment to control abduction and forward movement of the arm. The sleeve is attached to the longitudinal traction cable using a sterile hook, and a lateral strap is secured around the proximal portion of the sleeve to the overhead traction cable to ensure a field for glenohumeral reconstruction. The use of a lateral strap permits ideal shoulder positioning for improved access to the anterior and inferior glenohumeral joint. The lateral strap can be released or removed to widen the subacromial space during subacromial decompression or rotator cuff repair. A 10-lb weight is attached to the longitudinal traction cable for an average-sized person.