• Advances in robotics research
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• v.2 no.3
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• pp.183-199
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• 2018

This paper presents the development of a 3D printed humanoid robotic hands of SignBot, which can perform Malaysian Sign Language (MSL). The study is considered as the first attempt to ease the means of communication between the general community and the hearing-impaired individuals in Malaysia. The signed motions performed by the developed robot in this work can be done by two hands. The designed system, unlike previously conducted work, includes a speech recognition system that can feasibly integrate with the controlling platform of the robot. Furthermore, the design of the system takes into account the grammar of the MSL which differs from that of Malay spoken language. This reduces the redundancy and makes the design more efficient and effective. The robot hands are built with detailed finger joints. Micro servo motors, controlled by Arduino Mega, are also loaded to actuate the relevant joints of selected alphabetical and numerical signs as well as phrases for emergency contexts from MSL. A database for the selected signs is developed wherein the sequential movements of the servo motor arrays are stored. The results showed that the system performed well as the selected signs can be understood by hearing-impaired individuals.

• Journal of KIISE:Software and Applications
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• v.35 no.12
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• pp.780-788
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• 2008

Modeling hand poses and tracking its movement are one of the challenging problems in computer vision. There are two typical approaches for the reconstruction of hand poses in 3D, depending on the number of cameras from which images are captured. One is to capture images from multiple cameras or a stereo camera. The other is to capture images from a single camera. The former approach is relatively limited, because of the environmental constraints for setting up multiple cameras. In this paper we propose a method of reconstructing 3D hand poses from a 2D input image sequence captured from a single camera by means of Belief Propagation in a graphical model and recognizing a finger clicking motion using a hidden Markov model. We define a graphical model with hidden nodes representing joints of a hand, and observable nodes with the features extracted from a 2D input image sequence. To track hand poses in 3D, we use a Belief Propagation algorithm, which provides a robust and unified framework for inference in a graphical model. From the estimated 3D hand pose we extract the information for each finger's motion, which is then fed into a hidden Markov model. To recognize natural finger actions, we consider the movements of all the fingers to recognize a single finger's action. We applied the proposed method to a virtual keypad system and the result showed a high recognition rate of 94.66% with 300 test data.

• Therapeutic Science for Rehabilitation
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• v.12 no.1
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• pp.79-92
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• 2023

Objective : This study aimed to assess the reliability of a three-dimensional (3D) motion analysis program for measuring the range of motion (ROM) of wrist and finger joints. Methods : The study recruited 50 people who had no restrictions on wrist and finger movements, understood the purpose of this study, and agreed to participate. Using a goniometer and a 3D motion analysis program, a total of 11 wrist and finger ROM were measured once each. To measure the reliability of the 3D motion analysis program, the degree of agreement and inconsistency of the measured values were compared. Results : Analysis of the degree of agreement of the measured values revealed that 38 out of 44 items showed a very high degree of agreement. Regarding analysis of inconsistency in the measured values, inconsistencies were found in three items. Conclusion : The results of this study confirmed that the ROM of the joint could be measured using the 3D motion analysis program applied in this study. In addition, it might be expected that the 3D motion analysis program would be used in various clinical fields owing to the advantages of measurement convenience and accuracy.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10b
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• pp.185-190
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• 1993

The POSTECH Hand adopting coupled tendon driven technique with planar two fingers is developed. The hand is designed to emulate principal motions of the human hand which has two and three joints respectively. Its kinematic parameters are determined through a parameter optimizing technique to aim at improving the isotropy of fingertip motions with new criterion functions of design. For the control of the hand, tension and torque control algorithms are developed. Based on the virtual stiffness concept, we develop the stiffness control method of a grasped object with redundant finger mechnism and investigate experimentally.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.04a
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• pp.390-394
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• 1994

In many cases, tasks are unpredictable and therefore not doable by special-purpose or pro-programble robots. So master/slave type robot hands which combine human perceptions with conventional robot hands are required as robot end effector. These also can be applied to hazardous worksites such as outer space, deep sea and nuclear power plant. In this study, master/slave type robot fingers with 3 joints each are designed and constructed. To control force accurately, TDT(tension difference type) torque sensors are constructed and attached toeachjoints of slave finger and new force reflecting control algorithm is suggested. Finally, experimental results show that the new control algorithm can be successfully applied.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.40 no.8
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• pp.825-835
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• 1991

This paper deals with a case for robotic hands to grasp the objects using inner link contact as well as fingertip contact. And the case is proved to be more efficient than the case of using only fingertip contact in terms of stability and uniform distribution of the contact forces. The general algorithm for the determination of the optimal ocntact force is developed for the soft finger contact as well as the point contact with friction. To show the validity of the proposed algorithm a numerical example is illustated by employing a robotic hand with three fingers each of which has four joints.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.1
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• pp.73-80
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• 2004

We have developed a general purpose motion controller using an FPGA(Field Programmable Gate Array). The multi-PID controllers and GUI are implemented as a system-on-chip for multi-axis motion control. Comparing with the commercial motion controller LM 629, since it has multi-independent PID controllers, we have several advantages such as space effectiveness, low cost and lower power consumption. In order to test the performance of the proposed controller, motion of the robot hand is controlled. The robot hand has three fingers with 2 joints each. Finger movements show that tracking was very effective. Another experiment of balancing an inverted pendulum on a cart has been conducted to show the generality of the proposed FPGA PID controller. The controller has well maintained the balance of the pendulum.

• Safety and Health at Work
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• v.6 no.1
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• pp.9-17
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• 2015

The human hand is a complex structure that performs various functions for activities of daily living and occupations. This paper presents a literature review on the methodologies used to evaluate hand functions from a biomechanics standpoint, including anthropometry, kinematics, kinetics, and electromyography (EMG). Anthropometry describes the dimensions and measurements of the hand. Kinematics includes hand movements and the range of motion of finger joints. Kinetics includes hand models for tendon and joint force analysis. EMG is used on hand muscles associated with hand functions and with signal-processing technology.

• Journal of Trauma and Injury
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• v.32 no.1
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• pp.47-50
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• 2019

Irreducible dislocation of the distal interphalangeal (DIP) joint is a rare traumatic condition commonly seen in sports injuries. Herein, we present a case with chronic dislocation of the DIP joint caused by high energy trauma accompanied by a fracture of the ipsilateral clavicle. The local deformity resulting from the dislocation can be trivial. Therefore, obtaining radiographs of all the interphalangeal joint injuries, regardless of the findings on inspection, is crucial for accurate diagnosis in the case of high energy trauma. The good functional improvement was obtained by open reduction and temporary wire fixation for 4 weeks.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.4
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• pp.200-205
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• 1993

In many applications, the typical parallel-jaw end-effector of a robot arm has been remarkably satisfactory. But, it is not adequate for the applications such as complicated manipulation. In the study, a finger with 4 joints (so, having redundancy) was consturcted to investigate the characteristics of an articulated hand. Each joint was driven by one actuator, and the motor torque was transmited to each joint through a tendon-pulley system. In the context, major considerations for hardware design and the method to solve the inverse kinematics of a redundant manipulator were presented. Finally, the basic capabilities of an articulated hand were presented through experiments.