• Journal of Institute of Control, Robotics and Systems
• /
• v.19 no.11
• /
• pp.1043-1047
• /
• 2013

Smart mobile robot is a kind of Intelligent Robot. It means that operates manipulate autonomously and recognize the external environment. Smart mobile robot moving mechanism has many type and the type depend on the robot shape or purpose. Recently, research on the moving mechanism has been actively in many area. The moving mechanism divided to wheel type, crawler type, walking type, other type and the moving type choose by the kind of robot or the purpose robot. In this paper, describe the kind of moving mechanism on the smart mobile robot and the technical trend of moving mechanism of smart mobile robot.

• International Journal of Precision Engineering and Manufacturing
• /
• v.9 no.2
• /
• pp.44-49
• /
• 2008

This paper describes the problem of ultraprecision positioning with a ball screw mechanism in the microdynamic range, along with its solution. We compared the characteristics of two ball screw mechanisms with different table masses. The experimental results showed that the vibration resulting from the low stiffness of the ball screw degraded the positioning performance in the microdynamic range for the heavyweight mechanism. The proposed nominal characteristic trajectory following (NCTF) controller was designed for ultra precision positioning of the ball screw mechanism. The basic NCTF control system achieved ultra precision positioning performance with the lightweight mechanism, but not with the heavyweight mechanism. A conditional notch filter was added to the NCTF controller to overcome this problem. Despite the differences in payload and friction, both mechanisms then showed similar positioning performance, demonstrating the high robustness and effectiveness of the improved NCTF controller with the conditional notch filter. The experimental results demonstrated that the improved NCTF control system with the conditional notch filter achieved ultra precision positioning with a positioning accuracy of better than 10 nm, independent of the reference step input height.

• Journal of Institute of Control, Robotics and Systems
• /
• v.12 no.5
• /
• pp.464-472
• /
• 2006

This paper presents the two degree-of-freedom (DOF) planar parallel mechanism, called the $2{\underline{R}}RR-RP$ manipulator, whose degree-of-freedom is dependent on an additional passive constraining leg connecting the base and the platform. First, the kinematic analysis of the mechanism is performed: the inverse and forward kinematic problems are analytically solved, the workspace is systematically derived, and all of the singular configurations are examined. Then, in order to determine the geometric parameters the optimization of the mechanism is performed considering its dexterity, stiffness, and space utilization. Finally, the kinematic performances of the optimized mechanism are evaluated through the comparison study to the conventional 5-bar parallel manipulator.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.8 no.3
• /
• pp.389-395
• /
• 2013

Ethernet is the most widely deployed access network protocol around the world. IEEE 802.3az WG released the EEE standard based on LPI mode to improve the energy efficiency of Ethernet. This paper proposes improved adaptive power control mechanism that can enhance energy-efficiency based on EEE from small Ethernet switch. The feature of this mechanism is that it predicts the traffic characteristic of next cycle by measuring the amount of traffic flowing in during certain period and adjusts the optimal threshold value to relevant traffic load. Performance evaluation results indicate that the proposed mechanism improves overall performance compared to traditional mechanism, since it significantly reduces energy consumption rate, even though average packet delay increases a little bit.

• Journal of applied mathematics & informatics
• /
• v.7 no.2
• /
• pp.409-438
• /
• 2000

In this paper we develop a new procedure to control stepsize for Runge- Kutta methods applied to both ordinary differential equations and semi-explicit index 1 differential-algebraic equation In contrast to the standard approach, the error control mechanism presented here is based on monitoring and controlling both the local and global errors of Runge- Kutta formulas. As a result, Runge-Kutta methods with the local-global stepsize control solve differential of differential-algebraic equations with any prescribe accuracy (up to round-off errors)

• Proceedings of the IEEK Conference
• /
• 2000.11a
• /
• pp.21-24
• /
• 2000

End-to-end congestion control mechanism have been critical to the robustness and stability of the Internet. Most of today's Internet traffic is TCP, and we expect this to remain so in the future. TCP/IP is the intermediate transport layer candidate for today's applications. TCP uses an adaptive window-based flow control. The congestion avoidance and control algorithms deployed by TCP aims at using the available network bandwidth. This paper compares different congestion control policies, and proposes the new design mechanism for future public networks

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.11
• /
• pp.5135-5142
• /
• 2011

A flexible mechanism is proposed in this paper to improve the dynamic response performance of a traffic flow control system in an urban area. The roads, vehicles, and traffic control systems are all modeled as intelligent systems, wherein a wireless communication network is used as the medium of communication between the vehicles and the roads. The necessary sensor networks are installed in the roads and on the roadside upon which reinforcement learning is adopted as the core algorithm for this mechanism. A traffic policy can be planned online according to the updated situations on the roads, based on all the information from the vehicles and the roads. This improves the flexibility of traffic flow and offers a much more efficient use of the roads over a traditional traffic control system. The optimum intersection signals can be learned automatically online. An intersection control system is studied as an example of the mechanism using Q-learning based algorithm, and simulation results showed that the proposed mechanism can improve the traffic efficiency and the waiting time at the signal light by more than 30% in various conditions compare to the traditional signaling system.

• Journal of Institute of Control, Robotics and Systems
• /
• v.2 no.1
• /
• pp.45-52
• /
• 1996

This work deals with the kinematic and dynamic optimal design of a six degree-of-freedom Stewart Platform mechanism, which is actuated by six prismatic cylinfers. Composite design index is employed to deal with multi-criteria based design in a systematic manner, and a sequential design method is suggested, in which the results from the kinematic optimization are employed in the following dynamic optimization.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.35 no.1
• /
• pp.115-123
• /
• 2012

Material flow control mechanism is a kind of operational policy in manufacturing. It is very important because it varies throughput, throughput time, and work-in-process (WIP) under the same manufacturing resources. Many Researchers have developed various material flow control mechanisms and insisted that their mechanism is superior to others. However the experimental environment used in the performance comparison are different and impractical. In this paper, we set various manufacturing environments to fairly compare five previous material flow control mechanism : Push, Pull, CONWIP, Gated MaxWIP, and Critical WIP Loops. The simulation results show that the Push is superior to others in both of throughput and WIP if required demand is less than 80% of capacity. In addition, the performance of CONWIP and its variants are not different statistically.

• Journal of the Korea Convergence Society
• /
• v.1 no.1
• /
• pp.17-21
• /
• 2010

This paper proposes a mechanism for managing overload in real-time web service system. The many previous mechanisms manage overload with controlling web request. These mechanisms can control only new web request. They don't have any control existing tasks, especially periodic tasks. We design a controller that able to meet real-time performance with controlling even periodic tasks. A feedback control system is implemented applying the proposed mechanism. And we verified the stable operation of system.