• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.5
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• pp.14-20
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• 2006

In recent year, as the robot technology is developed, the researches on the artificial muscle actuator that enables robot to move dexterously like biological organ become active. Actuators are key technologies underpinning robotics. Breakthroughs in actuator technology, particular in terms of power-to-weight ratio, or energy-density, will have significant impacts upon the design and control of robotic system. In this paper, a new approach to design and control of shape memory alloy(SMA) actuator is presented to drive the robot hand. SMA wire is divided into many segments and their thermal states of the SMA are controlled individually in a binary manner. This control manner will reduce the hysteresis that the SMA material has and it becomes the fundamental technology to develop the anthropomorphic robot hand. In this paper, the mechanism In the digital step motor of the shape memory alloy that is driven by the segmented binary control, which is a new control technique, is studied. This SMA digital step actuator applies for the robot hand and the driving mechanism of the robot hand is investigated.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.78.6-78
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• 2002

$\textbullet$ The Gifu Hand III is a 5-fingered hand driven by built-in servomotors and has 20 joints with 10 DOF. $\textbullet$ The backlash of transmission, the mobility space, and the opposability of the thumb are improved. $\textbullet$ The new distributed tactile sensor with 859 detecting points is mounted on the hand surface. $\textbullet$ Experiments of grasping objects by a grasping strategy imitating human grasping reflex are shown.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1232-1235
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• 2005

In recent years, as the robot technology is developed the researches on the artificial muscle actuator that enable robot to move dextrously like biological organ become active. The widely used materials for artificial muscle are the shape memory alloy and the electroactive polymer. These actuators have the higher energy density than the electromechanical actuator such as motor. However, there are some drawbacks for actuator. SMA has the hysterical dynamic characteristics. In this paper the segmented binary control for reducing the hysteresis of SMA is proposed and the simulation of anthropomorphic robotic hand is performed using ADAMS.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.144-149
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• 2005

In recent years, as the robot technology is developed the researches on the artificial muscle actuator that enable robot to move dextrously like biological organ become active. The widely used materials for artificial muscle are the shape memory alloy and the electroactive polymer. These actuators have the higher energy density than the electromechanical actuator such as motor. However, there are some drawbacks for actuator. SMA has the hysterical dynamic characteristics. In this paper the segmented binary control for reducing the hysteresis of SMA is proposed and the simulation of anthropomorphic robotic hand is performed using ADAMS.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.1
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• pp.181-192
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• 1995

In this study, we introduce new types of planar 2 degree-of-freedom robot modules resembling the musculoskeletal structure of the human arm with actuation redundancy. First, for the given actuator sizes the performance analysis for the manipulator with redundant actuation and without redundant actuation is performed with respect to maximum load handling capacity, maximum hand velocity, and maximum hand acceleration. Secondly an algorithm which decides optimal actuator sizes for the given operational performances is introduced, and the optimal actuator sizes for a robot module with four redundant actuation are obtained. The algorithms employed in this paper will be useful to analyze the robot performances and to determine the actuator sizes for general robot manipulators.

• KIPS Transactions on Software and Data Engineering
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• v.11 no.9
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• pp.363-370
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• 2022

Grasping a target object among clutter objects without collision requires machine intelligence. Machine intelligence includes environment recognition, target & obstacle recognition, collision-free path planning, and object grasping intelligence of robot hands. In this work, we implement such system in simulation and hardware to grasp a target object without collision. We use a RGB-D image sensor to recognize the environment and objects. Various path-finding algorithms been implemented and tested to find collision-free paths. Finally for an anthropomorphic robot hand, object grasping intelligence is learned through deep reinforcement learning. In our simulation environment, grasping a target out of five clutter objects, showed an average success rate of 78.8%and a collision rate of 34% without path planning. Whereas our system combined with path planning showed an average success rate of 94% and an average collision rate of 20%. In our hardware environment grasping a target out of three clutter objects showed an average success rate of 30% and a collision rate of 97% without path planning whereas our system combined with path planning showed an average success rate of 90% and an average collision rate of 23%. Our results show that grasping a target object in clutter is feasible with vision intelligence, path planning, and deep RL.

• The Journal of Korea Robotics Society
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• v.10 no.1
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• pp.42-51
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• 2015

Peg-in-hole assembly is the most representative task for a robot to perform under contact conditions. Various strategies for accomplishing the peg-in-hole task with a robot exist, but the existing strategies are not sufficiently practical to be used for various assembly tasks in a human environment because they require additional sensors or exclusive tools. In this paper, the peg-in-hole assembly experiment is performed with anthropomorphic hand arm robot without extra sensors or devices using "intuitive peg-in-hole strategy". From this work, the probability of applying the peg-in-hole strategy to a common assembly task is verified.

• The Journal of Korea Robotics Society
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• v.10 no.4
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• pp.179-185
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• 2015

The versatility of a human hand is what the researchers eager to mimic. As one of the attempt, the redundant degree of freedom in the human hand is considered. However, in the force domain the redundant joint causes a control issue. To solve this problem, the force control method for a redundant robotic hand which is similar to the human is proposed. First, the redundancy of the human hand is analyzed. Then, to resolve the redundancy in force domain, the artificial minimum energy point is specified and the restoring force is used to control the configuration of the finger other than the force in a null space. Finally, the method is verified experimentally with a commercial robot hand, called Allegro Hand with a force/torque sensor.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.5
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• pp.487-495
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• 2012

In this paper, a Smart Home Service Robot, McBot II, which performs mess-cleanup function etc. in house, is designed much more optimally than other service robots. It is newly developed in much more practical system than McBot I which we had developed two years ago. One characteristic attribute of mobile platforms equipped with a set of dependent wheels is their omni- directionality and the ability to realize complex translational and rotational trajectories for agile navigation in door. An accurate coordination of steering angle and spinning rate of each wheel is necessary for a consistent motion. This paper develops trajectory controller of 3-wheels omni-directional mobile robot using fuzzy azimuth estimator. 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 4 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 McBot II is confirmed through live tests of the mess-cleanup task.

• 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.