• Journal of the Korean Society for Precision Engineering
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• v.31 no.8
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• pp.729-735
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• 2014

This paper presents the judgment method of the rehabilitation extent using a spherical type digital finger force measuring system (SDFFMS). Stroke patients can't use their fingers because of the paralysis of their fingers, but they can recover with rehabilitative training. The SDFFMS has been already developed by Kim (Author of this paper), and the finger grasping forces of normal people and stroke patients could be measured using it. But the SDFFMS could be not used to judge the extent of their rehabilitation, because the judgment method using it is not yet developed. In this paper, the characteristics tests for the grasping forces of normal persons and stroke patients were performed using the SDFFMS, and the judgment method of the rehabilitation extent was developed using the results. The tests confirm that the rehabilitation extent of stroke patients could be judged using the developed judgment method.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1060-1067
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• 2005

This paper attempts to derive and analyze the dynamic system of pinching a rigid object by means of two multi-degrees-of-freedom robot fingers with soft and deformable tips. It is shown firstly that a set of differential equation describing dynamics system of the manipulators and object together with geometric constraint of tight area-contacts is formulated by Lagrange's equation. It is shown secondly that the problems of controlling both the forces of pressing object and the rotation angle of the object under the geometric constraints are discussed. In this paper, the control method for dynamic stable grasping and enhancing dexterity in manipulating things is proposed. It is illustrated by computer simulation that the control system gives the performance improvement in the dynamic stable grasping of the dual fingers robot with soft tips.

• Journal of the Korean Society of Industry Convergence
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• v.21 no.4
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• pp.183-189
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• 2018

The focus of this paper is to design and control a three fingered hand system with eight axes for smart factory with an flexible controller, and to keep a useful big database for dynamic manipulation based on the experimental results. The weight of the hand module is only 1.2 kg, but flexible motion and powerful grasping are possible. To achieve such a flexible motion control of a robotic hand, we have developed a robust and precise fingered hand with a control system incorporating image recognition system in which we deal with the problems of not only accuracy and range of motion but also the flexibility of hand. The fingers are arranged so as to grasp both circular and prismatic objects. In order to achieve the light mechanism, we reduced the number of joints and fingers as much as possible. In this study, it was used three fingers with eight axes which is the optimal number to achieve a robust grasping diverse shape parts for smart factory.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.4
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• pp.81-88
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• 2005

This paper attempts to derive the dynamic model of handling tasks in finger robot which grasps stable and manipulates a rigid object with some dexterity. Firstly, a set of differential equation describing dynamics of the manipulators and object together with geometric constraint of tight area-contacts is formulated by Lagrange's equation. Secondly, the roblems of controlling both the forces of pressing object and the rotation angle of the object under the geometric constraints are discussed. The effect of geometric constraints of area-contacts between the link's end-effector and the object is analyzed and the model based on the differential-algebraic equations is presented. In this paper, the control method for dynamic stable grasping and enhancing dexterity in manipulating things is proposed. It is illustrated by computer simulation and the experiment that the control system gives the performance improvement in the dynamic stable grasping and nimble manipulating of the dual fingers robot with soft tips.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.10a
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• pp.568-576
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• 1998

In this thesis discuss with a flexible robotic finger design and controller which is used for the micro flexible robotic finger. So, miniaturization, precision, controller for the control of grasping force and actuator were needed. And, even if we develop a new actuator and controller, in order to use on real system, we must considerate of a many side problem. In a force control of micro flexible finger for grasping an object, the fingertip's vibration was more important task of accuracy control. And, controller were adopt the PD/PI mixed type fuzzy controller. The controller were consist of two part, one is a PD type fuzzy controller for increase the rising time response, the other is a PI type fuzzy controller for decrease of steady-state error. Especially, in a PD type fuzzy controller, we used only seven rules. And, for a PI controller, we adopt a reset factor for the control of input values. so, we have overcome the exceed of controller's input range. For the estimate of ontroller's utility and usefulness, we have experiment and computer simulation of three cases. First, we consider of unit force grasping control for a task object, which is 0.03N. Second, bounding grasping force control which is add to a sinusoidal force on the unit force. At this cases the task force is (0.03+0.01 sin wt N). And consider of following of rectangular forces.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2665-2669
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• 2003

A wearable device to assist fingering function for disabled is developed in this study. This is the second paper to report the progress in development of this assisting device. The device is developed for a patient who suffers from cervical spinal cord injury. In the first paper, it was reported that the patient could successfully pick up several types of objects with his paralyzed fingers by using this device. As a next step, the maneuverability of the device under grasping operation is discussed in this paper. Maneuverability of the system is experimentally evaluated. The dexterity in controlling finger force is compared between the cases that non-disabled examinees operate their finger with inherent abilities and that a disabled examinee operates his finger by using the assisting device.

• The Journal of Korea Robotics Society
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• v.9 no.4
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• pp.258-263
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• 2014

An adaptive robot hand (AR-Hand) has a stable grasp of different objects in unstructured environments. In this study, we propose an AR-Hand based on a tendon-driven mechanism which consists of 4 fingers and 12 DOFs. It weighs 0.5 kg and can grasp an object up to 1 kg. This hand based on the adaptive grasp mechanism is able to provide a stable grasp without a complex control algorithm or sensor system. The fingers are driven by simple tendon structures with each finger capable of adaptively grasping the objects. This paper presents a method to decide the joint stiffness. The adaptive grasping is verified by various grasping experiments involving objects with different shapes and sizes.

• Journal of the Korea Safety Management & Science
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• v.24 no.3
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• pp.47-53
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• 2022

In order to conduct a study on the importance of the wrist joint, which causes a lot of pain among middle-aged people, in relation to work related to musculoskeletal disorders, the effect of stretching on grasping power was studied. In order to compare the grasping power of the wrist for middle-aged people in their 50s, the experiment was conducted by comparing before and after the wrist joint motion stretching. According to the experimental results of wrist gripping power for the control group and the experiment group on wrist gripping power, it was investigated that stretching did not change much in increasing wrist gripping power, but stretching application had an effect on wrist gripping power. In terms of preventing musculoskeletal accidents, reducing pain due to degenerative diseases, and preventing accidents, stretching seems to have an effect when approaching, so it is considered that continuous stretching before and after work is necessary. Therefore, it is suggested that stretching time secured quantitatively through safety and health education before work is necessary.

• The Journal of Korea Robotics Society
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• v.18 no.4
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• pp.419-426
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• 2023

Assembly tasks are difficult to fully automate due to uncertain errors occurring in unstructured environments. When assembling parts such as electrical connectors, advances in grasping and assembling technology have made it possible for the robot to assemble the connectors without the aid of humans. However, some parts with tight assembly tolerances should be assembled by humans. Therefore, task sharing with human-robot interaction is emerging as an alternative. The goal of this concept is to achieve shared autonomy, which reduces the efforts of humans when carrying out repetitive tasks. In this study, a task-sharing robotic system for assembly process has been proposed to achieve shared autonomy. This system consists of two parts, one for robotic grasping and assembly, and the other for monitoring the process for robot-human task sharing. Experimental results show that robots and humans share tasks efficiently while performing assembly tasks successfully.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.138-141
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• 2002

In this paper, we developed a Master Hand which has 20 potentiometer for getting grasping data of human hands, a Slave Hand which has 20 DOF and five fingers with servo-motors, and a controller for the 7 DOF Arm with Multi-fingered hands. And, we programmed a 3D simulation S/W which controls a Robot System with Multi-fingered hands. A developed Robot System showed good performance in the grasping of an object with known position and shape.