• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.52-56
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• 1990

An algorithm is proposed to determine the optimal contact forces of robotic hands, where the soft finger contact as well as the frictional point contact are considered. Especially, the algorithm can be efficiently applied to the case of multi-point contact by inner-link as well as fingertip. To show the validities of the algorithm, several numerical exampies are presented by employing a robotics hand with three fingers each of which has four joints.

• The Journal of Korea Robotics Society
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• v.16 no.1
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• pp.64-71
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• 2021

This paper describes a robotic teleoperation system to perform an accurate needle insertion into a cornea for a separation between the stromal layer and Descemet's membrane during deep anterior lamellar Keratoplasty (DALK). The system can reduce the hand tremor of a surgeon by scaling the input motion, which is the control input of the slave robot. Moreover, we utilize corneal applanation to estimate the insertion depth. The proposed system was validated by performing the layer separation using 25 porcine eyes. The average depth of needle insertion was 742 ± 39.8 ㎛ while the target insertion depth was 750 ㎛. Tremor error was reduced from 402 ± 248 ㎛ in the master device to 28.5 ± 21.0 ㎛ in the slave robot. The rate of complete success, partial success, and failure were 60, 28, and 12%, respectively. The experimental results showed that the proposed system was able to reduce the hand tremor of surgeons and perform precise needle insertion during DALK.

• Korean Journal of Computational Design and Engineering
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• v.20 no.3
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• pp.246-253
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• 2015

In this paper, we propose calibration methods that can be applied to the markerless surgical robotic system for Intracerebral Hematoma (ICH) Surgery. This surgical robotic system does not require additional process of patient imaging but only uses CT images that are initially taken for a diagnosis purpose. Furthermore, the system applies markerless registration method other than using stereotactic frames. Thus, in overall, our system has many advantages when compared to other conventional ICH surgeries in that they are non-invasive, much less exposed to radiation exposure, and most importantly reduces a total operation time. In the paper, we specifically focus on the application of calibration methods and their verification which is one of the most critical factors that determine the accuracy of the system. We implemented three applications of calibration methods between the coordinates of robot's end-effector and the coordinates of 3D facial surface scanner, based on the hand-eye calibration method. Phantom tests were conducted to validate the feasibility and accuracy of our proposed calibration methods and the surgical robotic system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.5219-5226
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• 2011

A specialized anthropomorphic robot manipulator which can be attached to the housemaid robot McBot II, is developed In this paper. This built-in type manipulator consists of both arms with 3 DOF (Degree of Freedom) each and both hands with 3 DOF each. The robotic arm is optimally designed to satisfy both the minimum mechanical size and the maximum workspace. Minimum mass and length are required for the built-in cooperated-arms system. But that makes the workspace so small. This paper proposes optimal design method to overcome the problem by using neck joint to move the arms horizontally forward/backward and waist joint to move them vertically up/down. The robotic hand, which has two fingers and a thumb, is also optimally designed in task-based concept. Finally, the good performance of the developed manipulator is confirmed through live test of tasks.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2022-2026
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• 2003

We define that the end effector is the device which interact environment or objects with contact to execute tasks. Up to now, many researchers developed anthropomorphic robotic hands as end effectors. In this paper, we will discuss a problem on the development of a human-scale and motor-driven anthropomorphic robot hand. In this paper, design concept, actuator and transmission, kinematic design and sensing device are presented. By imitating the physiology of human hands, we devised new metacarpalphalangeal joint and interphalangeal joint suitable for human-size robot hands

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.700-704
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• 1989

A robotic system with a 3-dimensional profile measuring sensor is developed in order to measure the complicated shape of the target body. Due to this 3-dimensional profile measuring sensor, a computer is able to adjust the posture of the robot hand so that complicated global profile of the target body can be recognized after several measurements from the variant directions. In order to enable fast data processing, a digital signal processor and a look-up table is introduced.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1816-1819
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• 1997

Using the vision system, robotic tasks in unstructured environments can be accompished, which reduces greatly the cost and steup time for the robotic system to fit to he well-defined and structured working environments. This paper proposes a dynamic control scheme for robot manipulator with eye-in-hand camera configuration. To perfom the tasks defined in the image plane, the camera motion Jacobian (image Jacobian) matrix is used to transform the camera motion to the objection position change. In addition, the dynamic learning controller is designed to improve the tracking performance of robotic system. the proposed control scheme is implemented for tasks of tracking moving objects and shown to outperform the conventional visual servo system in convergence and robustness to parameter uncertainty, disturbances, low sampling rate, etc.

• International Journal of Control, Automation, and Systems
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• v.6 no.5
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• pp.740-745
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• 2008

This paper presents a new non-contact 3D robotic inspection system to measure the precise positions of screw and punch holes on a car body frame. The newly developed sensor consists of a CCD camera, two laser line generators and LED light. This lightweight sensor can be mounted on an industrial robot hand. An inspection algorithm and system that work with this sensor is presented. In performance evaluation tests, the measurement accuracy of this inspection system was about 200 ${\mu}m$, which is a sufficient accuracy in the automotive industry.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.543-548
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• 2000

In this study, an interactive programming method for robot in electronic part assembly task is proposed. Many of industrial robots are still taught and programmed by a teach pendant. The robot is guided by a human operator to the desired application locations. These motions are recorded and are later edited, within the robotic language using in the robot controller, and play back repetitively to perform robot task. This conventional teaching method is time-consuming and somewhat dangerous. In the proposed method, the operator teaches the desired locations on the image acquired through CCD camera mounted on the robot hand. The robotic language program is automatically generated and downloaded to the robot controller. This teaching process is implemented through an off-line programming software. The OLP is developed for an robotic assembly system used in this study. In order to transform the location on image coordinates into robot coordinates, a calibration process is established. The proposed teaching method is implemented and evaluated on an assembly system for soldering electronic parts on a circuit board. A six-axis articulated robot executes assembly task according to the off-line teaching in the system.

• Journal of the Korean Institute of Intelligent Systems
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• v.26 no.2
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• pp.147-152
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• 2016

Shape Memory Alloys (SMAs) undergo changes in shape and hardness when heated or cooled, and do so with great force. Since wire-type SMAs contract in length when heated and pull with a surprisingly large force and move silently, they can be used as actuactors which replace motors. These SMA actuators can be heated directly with electricity and can be used to create a wide range of motions. This paper presents the mechanical design and control for a three fingered, six degree-of-freedom robotic hand actuated by SMA actuators. Each finger has two joints and each joint is actuated with two tendons in the antagonistic manner. In order to create the sufficient force to make the smooth motion, the tendon is composed of two SMA actuators in parallel. For controlling the current to heat the SMA actuators, PWM drivers are used. In experiments, the antagonistic interaction of fingers are evaluated.