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

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.20 no.1
• /
• pp.35-43
• /
• 1996

A computer program for automatic deriving the symbolic equations of motion for robots using the programming language MATHEMATICA has been developed. The program, developed based on the Lagrange formalism, is applicable to the closed chain robots as well as the open chain robots. The closed chains are virtually cut open, and the kinematics and dynamics of the virtual open chain robot are analyzed. The constraints are applied to the virtually cut joints. As a result, the spatial closed chain robot can be considered as a tree structured open chain robot with kinematic constraints. The topology of tree structured open chain robot is described by a FATHER array. The FATHER array of a link indicates the link that is connected in the direction of base link. The constraints are represented by Lagrange multipliers. The parallel robot, DELTA, having three-dimensional closed chains is modeled and simulated to illustrate the approach.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.14 no.6
• /
• pp.732-736
• /
• 2004

Currently, the supply of Internet have been generalized. The technique and the equipment using internet are developing. We can use Internet well in an engineering research such timex flows. We can obtain the result and experimentation about a intelligent robot used of advantage that easily use internet. And other equipment can obtain the above experiment and result. Intelligent robot do not be affected by a limitation of wireless because it can load a wireless LAN equipped computer. The experiment is possible in the space which a wireless internet is just possible. In this paper, Internet-based Virtual Laboratory was consisted of a intelligent robot which load control computer and a general computer. Internet-based Virtual Laboratory have a multi-interface.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2002.11a
• /
• pp.27-30
• /
• 2002

Recently, there are lots of concerning on the control of multi-agent control system and mixed reality integrating real and virtual environments. In this paper, an integrated agent control system based on mixed reality and mobile environment is proposed. The system consists of a manager, agents, a mapping module, a geographic information module, a WAP server, and a mobile manager. The manager has Hybrid Device Manager(HDM) working for revising images and position data of the agents to display that at the 3D virtual and mobile environments respectively. Especially, the images of the agent is translated to LBM format and displayed on the mobile phone, and the current position of the agent is displayed on the display screen, so that a user are able to control the agent when he is moving. Experimental results shows the proposed system lets us control the agents conveniently at a computer and a mobile phone.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.12 no.3
• /
• pp.238-244
• /
• 2012

A modeling of vision based robot formation control system using fuzzy logic controller and extended Kalman filter is presented in this paper. The main problems affecting formation controls using fuzzy logic controller and vision based robots are: a robot's position in a formation need to be maintained, how to develop the membership function in order to obtain the optimal fuzzy system control that has the ability to do the formation control and the noise coming from camera process changes the position of references view. In order to handle these problems, we propose a fuzzy logic controller system equipped with a dynamic output membership function that controls the speed of the robot wheels to handle the maintenance position in formation. The output membership function changes over time based on changes in input at time t-1 to t. The noises appearing in image processing change the virtual target point positions are handled by Extended Kalman filter. The virtual target positions are established in order to define the formations. The virtual target point positions can be changed at any time in accordance with the desired formation. These algorithms have been validated through simulation. The simulations confirm that the follower robots reach their target point in a short time and are able to maintain their position in the formation although the noises change the target point positions.

• 제어로봇시스템학회:학술대회논문집
• /
• 2003.10a
• /
• pp.2676-2681
• /
• 2003

The Haptic Exploration Laboratory at The Johns Hopkins University is currently exploring many problems related to haptics (force and tactile information) in human-machine systems. We divide our work into two main areas: virtual environments and robot-assisted manipulation systems. Our interest in virtual environments focuses on reality-based modeling, in which measurements of the static and dynamic properties of actual objects are taken in order to produce realistic virtual environments. Thus, we must develop methods for acquiring data from real objects and populating pre-defined models. We also seek to create systems that can provide active manipulation assistance to the operator through haptic, visual, and audio cues. These systems may be teleoperated systems, which allow human users to operate in environments that would normally be inaccessible due to hazards, distance, or scale. Alternatively, cooperative manipulation systems allow a user and a robot to share a tool, allowing the user to guide or override the robot directly if necessary. Haptics in human-machine systems can have many applications, such as undersea and space operations, training for pilots and surgeons, and manufacturing. We focus much of our work on medical applications.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.24 no.6
• /
• pp.75-82
• /
• 2010

In this paper, we developed a new MSRDS(Microsoft Robotics Developer Studio) simulator for a quadruped pet robot with synchronization of virtual and real robots. By using this simulator, it is possible to reduce time and cost for gait and motion design and it will help for commercialization of service pet robots. In the research point of view, the simulator can be used to examine the model differences between the virtual and the real robots. Since this simulator implements the coordinated control of the virtual and real robots, it can be used as an internet game using two remote pet robots.

• 제어로봇시스템학회:학술대회논문집
• /
• 2003.10a
• /
• pp.2039-2044
• /
• 2003

The advanced infrastructure for accelerating the development of personal robots is presented. Based on this structure, effective ways for integrating the various commercial components and interfacing among them are studied. The infrastructure includes the technology such as modularization based on independent processing and standardization open to other developers. The infrastructure supports not only that each hardware component of a personal robot can be easily attached to and detached from the whole system mechanically but also that each software of the components can be functionally distributed. As a result, we developed the fully modularized personal robots mechanically, and a virtual machine for the control of these robots. In this paper the proposed infrastructure and its implementations are described.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2001.04a
• /
• pp.540-544
• /
• 2001

This paper addresses a hybrid control architecture for the hospital service robot, SmartHelper. In hybrid architecture, the deliberation takes place at planning layer while the reaction is dealt through the parallel execution of operations. Hence, the system presents both a hierarchical and an heterarchical decomposition, being able to show a predictable response while keeping rapid reactivity to the dynamic environment. The deliberative controller accomplishes four functions which are path generation, selection of navigation way, command and monitoring. The reactive controller uses fuzzy and potential field method for robot navigation. Through simulation under a virtual environment IGRIP, the effectiveness of the hybrid architecture is verified.

• Journal of the Korean Society for Precision Engineering
• /
• v.16 no.4 s.97
• /
• pp.138-147
• /
• 1999

For autonomous navigation, a legged robot should be able to walk over irregular terrain and adapt itself to variation of supporting surface. Walking through slope is one of the typical tasks for such case. Robot needs not only to change foot trajectory but also to adjust its configuration to the slope angle for maintaining stability against gravity. This paper suggests such adaptation algorithm for stable walking which uses feedback of reaction forces at feet. Adjusting algorithm of foot trajectory was studied with the estimated angel of slope without visual feedback. A concept of virtual slope angle was introduced to adjust body configuration against slope change of the supporting terrain. Regeneration of foot trajectory also used this concept for maintaining its stable walking against unexpected landing point.