• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.5
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• pp.459-467
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• 2011

Rehabilitation exercises must maintain a patient's interest and permit a quantitative evaluation of the rehabilitation. We have developed a haptic-device system. When users move a grip, the haptic device provides a virtual force that either assists the movement of their arm or working against it. To investigate the functional effect of this system in a rehabilitation program, we used for five subjects with motor-function disorders and measured the grip position, velocity, force exerted on the grip, and EMG activities during a reaching task of one subject. The accuracy of the grip position, velocity and trajectories patterns were similar for all the subjects. The results suggested that the EMG activities were improved by applying the virtual force to the grip. These results can be used for the development of rehabilitation programs and evaluation methods.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.4
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• pp.31-38
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• 2022

In this study, we designed and manufactured an intelligent gripper-control device to safely grip unknown objects. The gripper control device consists of a DSP circuit, power supply circuit, communication circuit, and amplifier circuit diagrams. The DSP is used because the values of the 3-axis force sensor to which the gripper is attached are measured and calculated at high speeds. The gripping force is determined based on this value, and the object must be safely gripped with the determined value. A basic characteristic test of the control device of the manufactured intelligent gripper was conducted, and it was confirmed that it operated safely.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.1038-1042
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• 2003

In order to evaluate dynamic impedance of a hand-arm system it is necessary to measure the hand-transmitted vibration and the reaction force at the same time while gripping the vibrating handle. In the study a device was developed to measure both the vibration and the force. The device consists of a measurement handle with four strain gauge and two accelerometers and a PC based control system with a program for the signal processing and evaluation of the hand-transmitted vibration and reaction force. The handle was installed on the vibration shaker so that it can move by the generated signal from the control system. As an application of the system dynamic reaction force and the frequency weighted acceleration at the handle attached to the shaker were measured at various grip force and feed force. This system will be very useful in the area of impedance measurement and the evaluation of performance of anti-vibration gloves.

• Transactions on Control, Automation and Systems Engineering
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• v.4 no.1
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• pp.9-16
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• 2002

In this paper, we intend to demonstrate a new intuitive force-feedback device for advanced VR applications. Force feed-back for the device is tension based and is characterized by 7 degrees of freedom (DOF); 3 DOF for translation, 3 DOF for rotation, and 1 DOF for grasp). The SPIDAR-G (Space Interface Device for Artificial Reality with Grip) will allow users to interact with virtual objects naturally by manipulating two hemispherical grips located in the center of the device frame. We will show how to connect the strings between each vertex of grip and each extremity of the frame in order to achieve force feedback. In addition, methodologies will be discussed for calculating translation, orientation and grasp using the length of 8 strings connected to the motors and encoders on the frame. The SPIDAR-G exhibits smooth force feedback, minimized inertia, no backlash, scalability and safety. Such features are attributed to strategic string arrangement and control that results in stable haptic rendering. The design and control of the SPIDAR-G will be described in detail and the Space Graphic User Interface system based on the proposed SPIDAR-G system will be demonstrated. Experimental results validate the feasibility of the proposed device and reveal its application to virtual reality.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.5
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• pp.107-115
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• 2008

In this research, it has been developed the tongs mechanism by a friction force for curbstone working. This tongs apparatus was farmed to grip and rotate the rectangular curbstone. Specification of this tongs apparatus has been determined by considering a loading weight and reversal load preventing reversal of 1.5 ton excavator. And, specification of the linear actuator has been determined with considering mechanical structure and the operation power demanded by the grip pad friction of tongs apparatus. The safety of the part has been examined from the 3D numerical simulation of the tongs apparatus. The operation system has been arranged to grip and rotate curbstone by on-off switching. The prototype has been established to carry out experiment after installing 1.5 ton excavator.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.11a
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• pp.245-248
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• 2005

This paper presents a novel user interface system which aims at easy controlling of mobile devices. The fundamental concept of the proposed interface is to launch an appropriate function of the device by sensing and recognizing the grip-pattern when the user tries to use the mobile device. To this end, we develop a prototype system which employs capacitive touch sensors covering the housing of the system and a recognition algorithm for offering the appropriate function which suitable for the sensed grip-pattern. The effectiveness and feasibility of the proposed method is evaluated through the test of recognition rate with the collected grip-pattern database.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.6 no.4
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• pp.304-313
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• 2006

This paper describes a novel way of applying capacitive sensing technology to a mobile user interface. The key idea is to use grip-pattern, which is naturally produced when a user tries to use the mobile device, as a clue to determine an application to be launched. To this end, a capacitive touch sensing system is carefully designed and installed underneath the housing of the mobile device to capture the information of the user's grip-pattern. The captured data is then recognized by dedicated recognition algorithms. The feasibility of the proposed user interface system is thoroughly evaluated with various recognition tests.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.12
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• pp.1011-1020
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• 2016

This paper introduces a tactilely transparent soft glove composed of soft materials and flexible structures. Although it is hard to achieve a high grasping force with conventional grip-assist gloves made from soft material, the proposed glove can exert a high force by using a novel structure. This structure has a triangular shape composed of flexible structural frames, soft fabric, and belts. It can produce grip-assist moment compliantly without harmful force or misalignment with the human fingers. The whole finger part that comes into contact with objects is made of thin and soft fabric in order to facilitate sensation transference. The proposed tactilely transparent soft glove enables the user to manipulate various objects owing to both the softness and high grasping force; it helps lifting heavy weight objects as well as permitting delicate tactile feeling on the palm and fingers. The proposed concept was applied to a two-finger grip-assist device for validation. In addition, the experimental results regarding grasping objects, fingertip force, and grasping force are presented.

• Journal of the Ergonomics Society of Korea
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• v.34 no.5
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• pp.447-454
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• 2015

Objective: The purposes of this study are to survey general and ergonomics relevant patents of major foreign countries, to classify the ergonomics patents into some categories frequently found in the patents lists surfed and to compare the results with those of Korea. Background: Under today's severe competitions between countries and between companies, the intellectual property has never been more important. It is needed to investigate Korea's positions and worldwide status of patent applications and grants for general and ergonomics patents. Method: This study was mainly based on relevant websites surfing such as KIPRIS, FPO, EPO, WIPO, etc. Results: The results showed that while Korea placed fourth in patent applications and grants in 2012, following US, Japan and China, Korea ranked seventh in the number of ergonomics patents. Of the overseas ergonomics patents, the proportion of tool/device was the second highest to category of others, followed by chair/desk, grip/handle and keyboard, etc. Compared to the overseas ergonomics patents, Korea showed a slightly different trend that there were less patents for specific fields of ergonomics such as grip/handle, keyboard, tool/device, etc. Conclusion: The number of ergonomics patents of Korea was behind most foreign countries surveyed in the number of patent applications and grants of, and there were many categories of overseas ergonomics patents. Application: This study would be used as a reference or guideline when developing varying ergonomic products or applying to ergonomics patents.

• Transactions of Materials Processing
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• v.15 no.3 s.84
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• pp.247-254
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• 2006

Rather than traditional manufacturing processes, miniature manufacturing processes usually require sophisticated equipments and characteristics of the processes of high cost and of low productivity. Contrarily, miniature stamping process can be realized in a low cost high productivity with relatively inexpensive equipments. In the meso scale, mechanical properties, especially work hardening characteristics, are discovered to be statically scattered and size dependent by intensive experimental and numerical investigations, which make the stamping process hard to apply to the miniature manufacturing. In this study, dual purpose experimental device that can be used for both miniature scale tensile test and miniature scale stamping by simple change of attachment has been developed. For the tensile test, the elongation has been measured with a combined use of a CCD camera and a linear encoder in order to account for the possibility of slippage between specimen and the grip and to ensure the accuracy of the measurement, while load has been measured with a load cell. To satisfy the required material properties for stamping, optimal annealing condition has been found by examining the microstructure of annealed specimen.