• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.4
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• pp.451-456
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• 2009

In this paper, a virtual force is generated and fed back to the operator to make the teleoperation more reliable, which reflects the relationship between a slave robot and an uncertain remote environment as a form of an impedance. In general, for the teleoperation, the teleoperated mobile robot takes pictures of the remote environment and sends the visual information back to the operator over the Internet. Because of the limitations of communication bandwidth and narrow view-angles of camera, it is not possible to watch certain regions, for examples, the shadow and curved areas. To overcome this problem, a virtual force is generated according to both the distance between the obstacle and the robot and the approaching velocity of the obstacle w.r.t the collision vector based on the ultrasonic sensor data. This virtual force is transferred back to the master (two degrees of freedom joystick) over the Internet to enable a human operator to estimate the position of obstacle at the remote site. By holding this master, in spite of limited visual information, the operator can feel the spatial sense against the remote environment. It is demonstrated by experiments that this collision vector based haptic reflection improves the performance of teleoperated mobile robot significantly.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.2
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• pp.137-142
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• 2015

Teleoperation of a robot arm working in hazardous environments has been studied in the field of defense and security. A master system is an essential part that plays an important role in the teleoperation. We developed a master system, which is an essential part in the teleoperation, so that it can operate the slave robot arm intuitively and has excellent mobility and portability compared to conventional master systems. The master system adopted a Stewart platform to minimize the size and weight, and the legs of the Stewart platform are composed of wires to improve the operation range of the system. The experimental validation of the developed master system is conducted with a commercial IMU, and the experimental results show that the proposed master system can perform reliable and dexterous teleoperation.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.8
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• pp.590-596
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• 2016

Biopsy is a typical needle type intervention procedure performed under radiographic image equipment such as computed tomography (CT) and cone-beam CT. This minimal invasive procedure is a simple and effective way for identifying cancerous condition of a suspicious tissue but radiation exposure for the patients and interventional radiologists is a critical problem. In order to overcome such trouble and improve accuracy in targeting of the needle, there have been various attempts using robot technology. Those devices and systems, however, are not for full procedure automation in biopsy without consideration for tissue sampling task. A robotic end-effector of a master-slave tele-operated needle type intervention robot system has been proposed to perform entire biopsy procedure by the authors. However, motorized sampling adopted in the device has different cutting speed from that of biopsy guns used in the conventional way. This paper presents the design of a novel robotic mechanism and protocol for the automation of biopsy procedure using spring-triggered biopsy gun mechanism. An experimental prototype has been successfully fabricated and shown its feasibility of the automated biopsy sequence.

• Korean Journal of Computational Design and Engineering
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• v.13 no.6
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• pp.429-439
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• 2008

With a remote operated manipulator system, the situation at a remote site can be rendered through remote visualized image to the operator. Then the operator can quickly realize situations and control the slave manipulator by operating a master input device based on the information of the virtual image. In this study, the remote operator visual support system (ROVSS) was developed for viewing support of a remote operator to perform the remote task effectively. A visual support model based on virtual environment was also inserted and used to fulfill the need of this study. The framework for the system was created by Windows API based on PC and the library of 3D graphic simulation tool such as ENVISION. To realize this system, an operation test environment for a limited operating site was constructed by using experimental robot operation. A 3D virtual environment was designed to provide accurate information about the rotation of robot manipulator, the location and distance of operation tool through the real time synchronization. In order to show the efficiency of the visual support, we conducted the experiments by four methods such as the direct view, the camera view, the virtual view and camera view plus virtual view. The experimental results show that the method of camera view plus virtual view has about 30% more efficiency than the method of camera view.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.12
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• pp.148-161
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• 1998

We investigate a design methodology for master arm which is employed in remote-site control. Though counter-balancing has been employed for the purpose of lessening the actuator loads, it results in the increase of dynamic load at the task position. Therefore, there exists a trade-off between counter-balancing and dynamic performance. The concept of a composite index is introduced to simultaneously consider those two effects in the design of master arms. Several alternative designs of master arms are suggested.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1513-1518
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• 1996

A force reflecting hand controller can be used to provide more realistic information to the operator of a teleoperation system such as kinesthetic feedback from a slave robot. In this paper, a new design concept of a force reflecting 6-DOF hand controller utilizing the kinematic structure of a Stewart Platform is presented. Based on the optimal design technique of a Stewart Platform, a force reflecting hand controller has been designed and constructed to verify the technical feasibility of proposed design concept. In order to provide an operator with kinesthetic feedback information, a force mapping algorithm based on a reciprocal product of screws has been introduced. Finally, the technical feasibility of the design concept has been demonstrated through some of experimental results of the device under virtual environment on a real-time graphic system.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2004.04a
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• pp.54-57
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• 2004

블루투스는 작은 크기와 저렴한 가격, 표준화된 프로토콜, 저전력 소모 등의 잇점으로 인해 로봇에 응용하기 적합한 무선 기술로 주목받고 있다. 그러나 단일 통신망을 구성하기 위해서는 1：7의 Master/slave 구조와 무선 통신거리 등의 제약사항이 있다. 블루투스를 로봇 시스템에 적용하기 위해서는 주위 환경에 따른 자기 조직화를 통해서 이러한 단점을 보완하고 주위 환경의 변화에 적절하게 대응을 할 수 있도록 하는 네트워크 구성 시스템이 필요하다. 자기 조직화를 하기 위해서는 Discovery, Organization, Maintenance, Reorganization의 크게 4단계의 과정을 거친다. 본 논문에서는 분산 로봇 시스템을 위해 트리구조를 이용한 자기 조직화 가능한 블루투스 네트워크를 구현하고 그 성능을 평가한다.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.132.5-132
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• 2001

In teleoperation field robotic system such as hydraulically actuated robotic excavator, the maneuverability and convenience is the most important part in the operation of robotic excavator. Particularly the force information is important in dealing with digging and leveling operation in the teleoperated excavator. Excavators are also subject to a wide variation of soil-tool interaction forces. This paper presents a new force reflecting joystick in a velocity-force type bilateral teleoperation system. The master system is electrical joystick and the slave system is hydraulically actuated cylinder with linear position sensor. Particularly Pneumatic motor is used newly in the master joystick for force reflection and the information of the pressure of salve cylinder is measured and utilized as the force feedback signal. Also force-reflection gain greatly affects the ...

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.404-407
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• 1995

Teleoperating system has been developed for several decades, and many control schemes for it have been suggested. But the implementation for real application needs very simple but effective controller. In this paper, an advanced control scheme for this purpose is suggested, which is the combination of a modified internal model controller and variable filter for force reflection. And we verify the effectiveness of the proposed scheme through the experiment. We use PUMA-560 as the slave robot, which is operated by velocity servo loop with geared motor. Both the responses of free motion and contact motion are shown.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.602-607
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• 1990

Spent nuclear fuel is very dangerous substance emitting strong ionizing radiation which is harmful to human body. The remote handling of spent nuclear fuel is essential because people cannot access this substance without protecting radiation. To handle highly radioactive material or nuclear waste, many kinds of teleoperators such as master slave manipulator, electro mechanical manipulator, servo manipulator, mobile robot was developed. The distance and dimension of target object cannot be measured easily when highly radioactive material is handled by teleoperator because one should use lead glass or TV camera and monitor to protect radiation and see target object. During experiments on the remote handling of spent nuclear fuel by electro mechanical manipulator, we often felt that a distance and dimension measurement system is necessary to handle the objects which is in the highly radioactive environment, so we developed a system which is appropriate for this purpose.