• Journal of the Korean Society of Industry Convergence
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• v.25 no.6_1
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• pp.953-959
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• 2022

In this paper, the design result of robotic tools and the development of robot control system for chemical coupler assembly are presented. This research aims to eliminate the risk of chemicals exposed to human operators by developing the robotic tools and robot automation system for chemical tank lorry unloading that were done manually. Due to tight tolerance between couplers, even small pose error may result in very large internal force. In order to resolve the problem, the 6-axis compliance device is employed, which can provide not only enough compliance between couplers but also F/T sensing. The 6-axis compliance device having large force and moment capacity is designed. A simple linear gripper with rack-and-pinion is designed to grasp two sizes of couplers. The proposed robot automation system consists of 6-DOF collaborative robot with offset wrist, 6-axis compliance device with F/T sensing, linear gripper, and two robot visions.

• Journal of the Ergonomics Society of Korea
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• v.24 no.2
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• pp.65-70
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• 2005

Evaluation of repetitiveness for upper extremity intensive tasks is essential to determine the level of risk for upper extremity musculoskeletal disorders at the workplace. However, experimental data available to establish the acceptable levels of repetitiveness for various postures and forces is lacking. The present study examined the maximum acceptable frequencies(MAFs; motions/min.) of shoulder, elbow, wrist, and index finger motions at different forces(1kgf and 4kgf for shoulder, elbow, and wrist; 0.25kgf and 1 kgf for index finger) in sitting. Seventeen right-handed males in 20s without having any history musculoskeletal disorders participated in the MAF experiment. The participants determined their MAFs for the upper extremity motions by using the self-adjustment method and their work pulse(increase in heart rate; beats/min.) and rating of perceived exertion(RPE) were measured when working at MAF. The MAFs of elbow, wrist, and index finger motions for each force level were about 2, 3, and 6 times the corresponding MAF(9 at the high force and 24 at the low force) of shoulder motion and the MAFs at the low force increased about 2 times those at the high force. The work pulses of elbow, wrist, and index finger motions for each force level were 70%, 50%, and 30% of the corresponding work pulse(17 at the high force and 12 at the low force) of shoulder motion and the work pulses at the low force were about 70 % of those at the high force. Lastly, the RPEs of the upper extremity regions were about level 3(moderate) or below.

• Journal of radiological science and technology
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• v.36 no.1
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• pp.19-24
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• 2013

The measurement of Korea people's Radial-terminal region were frequently measure of the left hand of Radial-terminal region due to the most Korean's are right-handed and it occasionally showed incorrect results. Therefore, in this study, we accessed a correlation with error of measurement and reduced the measurement error invalid. We reviewed 50 adults patients, from March 2012 for a certain period of time, visited the orthopedic center for the neutral position of forearm of plain radiography and measured the left side of the distal radial-terminal region containing the terminal region of the right distal radius. Then we have compared and analysed both T-score. As a result, the lower value of left wrist were 45 out of 75 which is approximately 60% of left wrist group while the lower value of right wrist were 30 out of 75 which is approximately 40% of right wrist group.

• International Journal of Precision Engineering and Manufacturing
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• v.8 no.4
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• pp.16-21
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• 2007

Robotic applications, such as automatic fish cutting, require online trajectory planning because the material properties of the object, such as the bone or flesh conditions, are not known in advance. Different trajectories are required when the material properties vary. An effective online trajectory-planning algorithm is proposed using quaternions to determine the position and orientation of a robot manipulator with a spherical wrist. Quaternions are free of representation singularities and permit computationally efficient orientation interpolations. To prevent singular configurations, the exact locations of the kinematic singularities of the PUMA 560 manipulator are derived and geometrically illustrated when a forearm offset exists and the third link length is not zero.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.211-215
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• 1989

This paper describes a dynamic robotic assembly system in which an industrial robot executes peg-in-hole task in a moving state. As an effective means to synchronize the end-effector of the robot with the moving conveyor this work uses a control algorithm which is essentially a PID position control scheme combined with velocity feedforward loop. A RCC wrist is used for the inserting task and its force responses are investigated for various tracking conditions and inserting velocities through a series of experiments.

• Physical Therapy Korea
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• v.9 no.3
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• pp.113-124
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• 2002

The objectives of this study was to investiage the effects of sitting posture on carpal tunnel syndrome. Carpal tunnel syndrome (CTS) continues to be one of the most widely publicized maladies of the cumulative trauma disorder. Many studies have reported a positive association between CTS and highly repetitive work, high force, and poor posture. High force and repetitive work have especially been associated with CTS, but the evidence for work being a primary cause of CTS is strongest when these factors are combined. In addition to carpal tunnel syndrome, hand, wrist, and other disorders are attributed to these work-related movements. Such disorders are referred to as repetitive stress injuries, cumulative trauma disorder, overuse syndromes, and chronic upper limb pain syndrome. Incorrect posture also may play a role in the development of CTS in people who work at a computer and other types of keyboards. The tendency to roll the shoulders forward, round the lower back, and thrust the chin forward can shorten the neck and shoulder muscles, compressing nerves in the neck. This, in turn, can affect the wrist, fingers, and hand. The treatment and prevention of carpal tunnel syndrome continue to be approached with a segmental view of the human body. For example, the most common ergonomic solution for carpal tunnel syndrome associated with keyboard use is to keep the wrists in a neutral position by using a wrist rest in front of the keyboard and good sitting posture.

• Korean Journal of Applied Biomechanics
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• v.16 no.3
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• pp.33-41
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• 2006

This study was to analysis three dimension angle of the upper extremity segment and trunk to putting the protector in women bowlers. For this study, the subjects selected 4 players of national and university team. All subjects putted in the same wrist support to satisfy the experiment conditions. To get three dimensions position coordination of swing motion used for 6 ProReflex MCU 240 camera produced by Qualisys. After position coordination calculation, Three dimension angle of the trunk and the upper extremity segment calculated for Matlab 6.5. the result is following; In the trunk motion, there were little differences among the subjects in a flexion and extension change. There were a lot of differences in motion change of the abduction-adduction and internal-external rotation, but the motion types translated to the adduction-abduction-adduction and from the internal rotation toward the external rotation. In the upper arm segment the Flexion and extension showed a consistent motion in the down swing and up swing phase. And the motion change of abduction-adduction and pronation-supination showed a abduction-adduction-abduction and pronation-supination change during swing phase. In the forearm segment changes, it showed a lot of differences among the subjects and a similar change with the upper arm segment. Especially, the hand segment showed a supination motion from the backswing apex to release phase, but for increasing a rotation velocity of ball, the hand segment translated toward pronation in follow throw phase.

• The Journal of Korea Robotics Society
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• v.15 no.2
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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.

• Physical Therapy Korea
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• v.7 no.1
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• pp.91-100
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• 2000

This study investigates the influence of cane length on the weight distribution of the elderly in a standing position. Thirty participants were evaluated using two different cane lengths based on measurements of distal wrist crease to ground (WC cane), and distance of greater trochanter to ground (GT cane). A limloader was used to determine the weight distribution on the subject. It was found that 6.5% of body weight was supported on a GT cane and 7.7% of body weight supported on a WC cane in a standing position. Results suggests that more weight is distributed on a WC cane than a GT cane in the elderly.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.764-767
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• 2009

Motion capture systems allow to measure the precise position of markers on the human body in real time. These captured motion data, the marker position data, have to be fitted by a human skeleton model to represent the motion of the human. Typical human skeleton models approximate the joints using a ball joint model. However, because this model cannot represent the human skeleton precisely, errors between the motion data and the movements of the simplified human skeleton model happen. We propose in this paper a method for measuring a translation component of wrist, and elbow joints on upper limb using optical motion capture system. Then we study the errors between the ball joint model and acquired motion data. In addition, we discuss the problem to estimate motion of human joint using optical motion capture system.