• Journal of Biosystems Engineering
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• v.26 no.6
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• pp.535-544
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• 2001

This study developed a manipulator for robotic harvester to harvest cucumber. The manipulator was designed and built fur transferring an end-effecter from a fixed point to a specified cucumber. Its development involved the integration of a manipulating system with a PC compatible, DC motors, geared boxes, timing belts, and a motor controller board. Software, written in Quick basic. combined the functions of motor control with various circumstances. In order to move smoothly and rapidly the manipulator, it's shoulder link and elbow link were minimized by using rotational inertial moment without a motor and a geared box. After 30 replications of exercising the manipulator, it was concluded that the precision values of the X, Y and Z axes were less than 0.5mm, 7.25mm and 0.35mm, respectively. The precision data indicated the manipulator was not missing any steps fur the harvester to reach a target cucumber.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.113-118
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• 2005

Robots today have wider application fields than they ever have before. They need to work close to humans and fluid and compliable motions are expected of them. This requires redundant degrees of freedom for completing specific task. And conventional motion teaching method cannot be applied to redundant link structures. In this paper, the authors present a proficient, cost-effective and intuitive method for motion teaching. New software to apply this method to a humanoid is also presented. This new method utilizes current sensors to determine which joints to rotate. The experiment shown in this paper is a case of closed link where arms cannot move independently due to the restrictions in between the hands. After the input of several passing points of motion trajectory, the curve fitting is performed by the developed software. This software can insert new points, delete erroneous points and modify existing points. The developed motion teaching method is applied to the Kumdo robot, which is developed by the authors.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.5
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• pp.959-975
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• 2011

Wireless mesh networks enlarge the wireless coverage area by interconnecting relatively stationary wireless routers (mesh routers). As wireless mesh networks are envisioned to provide high-bandwidth broadband Internet service to a large community of users, the Internet gateway, which acts as a central point of Internet attachment for the mesh networks, is likely to suffer heavily from the scramble for shared wireless resources because of aggregated traffic toward the Internet. It causes performance decrement on end-to-end transmissions. We propose a scheme to balance the load in a mesh network based on link quality variation to different Internet gateways. Moreover, under the mesh coverage, mobile nodes can move around and connect to nearby mesh routers while still keeping the connections to the Internet through the best gateway in terms of link quality. In this structure, gateways perform the balancing procedure through wired links. Information about gateways and mobile node's location is distributed appropriately so that every mesh router can quickly recognize the best gateway as well as the positions of mobile nodes. This distributed information assists mobile nodes to perform fast handoff. Significant benefits are shown by the performance analysis.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.818-829
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• 2003

A cooperating control algorithm for two nonholonomic mobile robots is proposed. The task is composed of collision avoidance against obstacles and carrying a ladder. The front robot and the rear robot are called the leader and the follower, respectively. Each robot has a nonholonomic constraint so it cannot move in perpendicular directions. The environment is initially supposed to be unknown except target position. The torque that drives leader is determined by distance between the leader and the target position or the distance between it and the obstacles. The torque by target is attractive and the torque by obstacles is repulsive. The two mobile robots are supposed to be connected by link that can be expanded and contracted. The follower computes its torque using position and orientation information from the leader by communication. Simulation results show that the robots can drive to target position without colliding into the obstacles and maintain the distance in the allowable range.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1841-1846
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• 2003

The mobile platform-manipulator discussed in this paper is a three link manipulator mounted on a mobile platform. This mobile manipulator is used for welding operation and it is able to operate in a narrow space. The task of the torch, which is mounted at the end effector of the manipulator, is to track along the seam line and the task of the mobile platform is to move the origin point of the manipulator in order to go away from the singularity of the manipulator’s configuration. In this paper, the path planning for the motion of two subsystems (i.e., the manipulator and the mobile platform) was presented by the decentralized control method. Two controllers for the mobile platform and the manipulator were designed, and the relationship between the independent controllers is its state information. The simulation results are also presented to demonstrate the effectiveness of the control method.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.653-656
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• 2004

This paper outlines the three main fieldbus type standards: Foundation Fieldbus; WorldFIP; and the Profibus, each of which have great advantages over traditional instrumentation networking technology. The paper shows, using their specification, how they improve traditional control and data acquisition methods. By analysing the main robust, how the can be used to distribute data around the control system, provided increased diagnostic information, are easy to implement, fault confinement, and move simple control operations from the main controller to the local environment. This will help to segment industrial plants into zones which can control themselves. The main control will then be responsibility high-level control. and interzone communications.

• Journal of Power System Engineering
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• v.7 no.1
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• pp.34-41
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• 2003

A method is presented for generating the path which significantly reduces residual vibration of a flexible robot manipulator and applying control theory to track the desired path. The desired path is optimally designed so that the system completes the required move with minimum residual vibration. A closed loop control theory is applied to track the planned path in the case of load variation. Specifically, it is desired that the optimally designed path has a better trajectory tracking capabilities during the residual vibration over the cycloidal path, in various cases of load. Perturbation adaptive control is used as closed loop control scheme. A planar two link manipulator is used to evaluate this method.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.341-344
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• 2005

Mobile IPv6(MIPv6) allows a Mobile Node to talk directly to its peers while retaining the ability to move around and change the currently used IP address. One of the major issues regarding the basic Mobile IPv6 protocol is related to the handover management of a mobile node. This paper proposes efficient approach for adaptation of MIPv6 sing context information in roaming environments. To investigate on a efficient and secure handover procedure, proposed approach method will give us the following advantages: (l)the intention of context is to reduce latency, packet losses and avoid re-initiation of signaling to and from mobile nodes,(2) FMIPv6 aims to reduce handover latency due to IP protocol operations as small as possible in comparison to the inevitable link switching latency.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.12
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• pp.1184-1191
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• 2009

Energy harvesting from environment can make the energy constrained systems such as sensor networks to sustain their lifetimes. However, environmental energy is highly variable with time, location, and other factors. Unlike the existing solutions, we solved this problem by allowing the sensor nodes with mobilizer to move in search of energy and recharge from remote energy station. In this paper we present and analyze a new harvesting aware framework for mobile sensor networks with remote energy station. The framework consists of energy model, motion control system and data transfer protocol. Among them, the objective of our data transfer protocol is to route a data packet geographically towards the target region and at the same time balance the residual energy and the link connectivity on nodes with energy harvesting. Our results along with simulation can be used for further studies and provide certain guideline for realistic development of such systems.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.14-20
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• 2003

Supply chain is the link that moves products between suppliers, manufactures, wholesalers, distribution, retailers and ended consumers. Supply chain management(SCM) is a way to supervise the flow of products, materials and information as they move along the supply chain. In the recent years, Most of the companies are in a hurry the introduction of SCM to obtain international competitiveness. The goal of SCM is to optimize the supply chain, which can not only reduce inventories, but may also create a higher profit margin for finished goods by giving customers exactly what they want. There are four major decision areas (location, production, inventory, transportation) in supply chain management, and there are both strategic and operational elements in each of these decision areas. This paper is concerned with the integrated production planning problem including not only the production cost but also the transportation cost in supply chains, and an efficient algorithm using genetic algorithm and quickest path method is presented to solve the problem.