• Journal of the Korean Society for Precision Engineering
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• v.28 no.9
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• pp.1048-1053
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• 2011

Recently, robots have been used in surgical area. Robotic surgery in Minimally Invasive Surgery gives many advantages to surgeons and patients both. This study introduce a robotic assistant to improve the safety of telerobotic Minimally Invasive Surgical procedures. The master-slave system is applied to the telerobotic surgical system with the master arm, which control the system, and slave robot which operates the surgery on the patient body. By using a 3-DOF master arm, the surgeon can control the 6-DOF surgical robot under the constraint of fulcrum point. This paper explains the telerobotic surgical system and confirms the system with the precision of the robot control related to the fulcrum point to enhance the safety.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.3 no.2
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• pp.244-250
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• 2003

In this paper, the relationship between a slave robot and the uncertain remote environment is modeled as the impedance to generate the virtual force to feed back to the operator. For the control of a tele-operated mobile robot equipped with camera, the tele-operated mobile robot take pictures of remote environment and sends the visual information back to the operator over the Internet. Because of the limitation of communication bandwidth and narrow view-angles of camera, it is not possible to watch the environment clearly, especially shadow and curved areas. To overcome this problem, the virtual force is generated according to both the distance between the obstacle and robot and the approaching velocity of the obstacle. This virtual force is transferred back to the master over the Internet and the master(two degrees of freedom joystick), which can generate force, enables a human operator to estimate the position of obstacle in the remote environment. By holding this master, in spite of limited visual information, the operator can feel the spatial sense against the remote environment. This force reflection improves the performance of a tele-operated mobile robot significantly.

• 제어로봇시스템학회:학술대회논문집
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• 1998.10a
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• pp.386-390
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• 1998

A master-slave system is proposed as a teaching device for a dual arm robot. The slave robots are remotely controlled by two delta-type master arms. In order to help the operator to observe the target object from the desired position and desired direction, cameras are mounted on a specialized manipulator, Movements of two slave arms are coordinated with that of the cameras. Due to this coordinated movements, the operator needs not to care the geometrical relation between the cameras and the slave robots.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.737-741
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• 2004

A mobile robot system is developed which is remotely controlled by a haptic master called ‘PHANTOM’. The mobile robot has 4 ultrasonic sensors and single CCD camera which detects the distance from a mobile robot to obstacles in the environment and sends this information to a haptic master. For more convenient remote control, haptic rendering process is performed like viscosity forces and obstacle avoidance forces. In order to show the effectiveness of the developed system, we experiment that the mobile robot runs through the maze and the time is checked to complete the path of the maze with/without the haptic information. Through this repeated experiments, haptic information proves to be useful for remote control of a mobile robot.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.95-97
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• 2005

This paper deals with the implementation of walking for a humanoid robot by ZMP measurement using wireless sensor network. ZMP is measured by FSR sensors which are mounted at each corner of a sole. The wireless sensor network collects the sensor data according and exchanges robot information between host PC and a robot system. The master controller mounted on robot body receives trajectory data from the host PC via sensor network and drives the joint motor based on trajectory data. The time scheduler of the master controller controls the events at the ratio of 100ms. With this configuration, the walking of the humanoid robot KHR-1 could be realized successfully.

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.6
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• pp.746-753
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• 2008

In this paper, we introduce the improved control method are communicated between a master and a slave robot in the teleoperation systems. When the master and slave robots are located in different places, time delay is unavoidable under the network environment and it is well known that the system can become unstable when even a small time delay exists in the communication channel. The time delay may cause instability in teleoperation systems especially if those systems include haptic feedback. This paper presents a control scheme based on the estimator with virtual master model in teleoperation systems over the network. As the behavior of virtual model is tracking the one of master model, the operator can control real master robot by manipulating the virtual robot. And LQG/LTR scheme was adopted for the compensation of un-modeled dynamics. The approach is based on virtual master model, which has been implemented on a robot over the network. Its performance is verified by the computer simulation and the experiment.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.4
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• pp.295-304
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• 2000

In the teleoperation system, force and velocity signals are communicated between a master and a slave robot. The addition of force feedback to a teleoperation system benefits the operator by providing more information to perform given tasks especially for tasks requiring contact with environment. When the master and slave arms are located in different places, time delay is unavoidable and it is well known that the system can become unstable when even a small time delay exists in the communication channel. The control scheme proposed in this paper is based on the estimator with virtual master model. Delayed signal from the master robot can be replaced by the estimated signal with the virtual master model. This control scheme makes the teleoperation system stable for the given time delay while the conventional scheme is not. This new control scheme is verified through numerical simulations and an experiments using the dual axis testbed of the teleoperation system.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.9 no.3
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• pp.244-248
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• 2009

This paper describes a real-time EtherCAT Master library. The library is developed using Xenomai. Xenomai is a real-time development framework. It cooperates with the Linux kernel, in order to provide a pervasive, interface-agnostic, hard real-time support to user-space applications, seamlessly integrated into the GNU/Linux environment. The proposed master library implements EtherCAT protocol for master side, and supports Application Programming Interfaces(APIs) for programming of real-time application which controls EtherCAT slave.

• Journal of Biomedical Engineering Research
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• v.29 no.1
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• pp.32-39
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• 2008

This paper reports on a realtime OS based master-slave configuration robot control system for laparoscopic surgery robot which enables telesurgery and overcomes shortcomings with conventional laparoscopic surgery. Surgery robot system requires control system that can process large volume information such as medical image data and video signal from endoscope in real-time manner, as well as precisely control the robot with high reliability. To meet the complex requirements, the use of high-level real-time OS (Operating System) in surgery robot controller is a must, which is as common as in many of modem robot controllers that adopt real-time OS as a base system software on which specific functional modules are implemened for more reliable and stable system. The control system consists of joint controllers, host controllers, and user interface units. The robot features a compact slave robot with 5 DOF (Degree-Of-Freedom) expanding the workspace of each tool and increasing the number of tools operating simultaneously. Each master, slave and Gill (Graphical User Interface) host runs a dedicated RTOS (Real-time OS), RTLinux-Pro (FSMLabs Inc., U.S.A.) on which functional modules such as motion control, communication, video signal integration and etc, are implemented, and all the hosts are in a gigabit Ethernet network for inter-host communication. Each master and slave controller set has a dedicated CAN (Controller Area Network) channel for control and monitoring signal communication with the joint controllers. Total 4 pairs of the master/slave manipulators as current are controlled by one host controller. The system showed satisfactory performance in both position control precision and master-slave motion synchronization in both bench test and animal experiment, and is now under further development for better safety and control fidelity for clinically applicable prototype.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.11
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• pp.171-179
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• 2003

This paper presents a rehabilitation exercise system which utilizes a 6 DOF robot as a motion generator. This system was proposed for a stroke patient or a patient who has hemiplegia. A master-slave system was designed to exercise either paralysis or abnormal limb by using normal limb motion. The study on the human body was applied to calculate the motion range of elbows and shoulders. In addition, a force-torque sensor was applied to the slave robot to estimate the rehabilitation extent of the patient. Therefore, the stability of the rehabilitation robot could be improved. By using the rehabilitation robot. the patients could exercise by themselves without assistance. In conclusion, the proposed system was verified by computer simulations and system experiment.