• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.558-560
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• 1998

The operation of robot manipulators has a restriction that the operator must reside at the factory, where the manipulator is used. To overcome this restriction, we propose a remote control system using the internet, the system which runs on the Window 95 environment is composed of the remote client which transfers commands to the server which control and manage the manipulator in the factory. In the control of Hong-ik Direct Drive Arm, it is necessary to consider the complex nonlinear parameters causing the mutual interaction between joints, so we use two TMS320C31 DSP chips in the controller for the real time dynamic control algorithms. For the test of system integrity and the verification of the mathematical modeling, we apply CTM, PD and VSS control algorithms and the simulation results are satisfactory.

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.2
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• pp.246-253
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• 2013

The Modular Multilevel Converter (MMC) with full bridge cells is available for utility interactive inverter in high voltage line. When it is interconnected with power line, it is possible to control the active power flow in order to supply or charge the power in the line. This research applied the MMC to grid connection system of distributed generator and a power flow control for the MMC is investigated. Theory of power flow between the MMC and the power line is described and control method of power flow and capacitor voltages on arm cells for the MMC are proposed. And effectiveness of the proposed control method is presented by simulation.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.1
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• pp.34-44
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• 2000

In this paper, a modified skyhook control for the semi-active Macpherson suspension system is investigated. A new model for the semi-active type suspension, which incorporates the rotational motion of the unsprung mass, is introduced and an output feedback control law using the skyhook control method is derived. The gains in the skyhook controller are adaptively adjusted by estimating the road conditions. Because two vertical acceleration sensors, one for the sprung mass and another for the unsprung mass, are used rather than using the angle sensor for the rotational motion of the control arm, the relative velocity of the rattle space is filtered using the acceleration signals. For testing the control performance, the actual damping force has been incorporated via the hardware-in-the-loop simulations. The performances of a passive damper and a semi-active damper are compared. Simulation results are provided.

• The Journal of Pediatrics of Korean Medicine
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• v.23 no.1
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• pp.95-113
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• 2009

Objectives This study was investigated to find how the orally administrated Moschus, herbal combination with Moschus, and herbal combination improves the rats' memory and rats' liver. These medications are generally known asthe memory improvement. Methods This study used the Sprague Dawley rats. They were divided into two groups - SD rats and orally administrated Saline(Control group). 0.473 mg/kg Moschus(HM-A), 153.9 mg/kg herbal composition without Moschus(HM-B), and 165.95 mg/kg herbal composition with Moschus combined(HM-C) Control, saline were orally administered. Each group was trained in the eight-arm radial maze task at the conditions of before oral administrated, and also right after third, sixth, and eighth by oral administration. Lastly, these animals were killed and were tested for brain tissue and serum AST/ALT level to measure how the medications were effected to the liver function. Results The result of radial eight-arm maze task test, the HM-B and HM-C groups showed significant decrease in mistakes from the fourth day of testing. Whereas, the HM-A group showed increasing in the error rate. HM-A and HM-C group of rats had significantly increased amount of acetylcholinesterase in the CA1 region of hippocampus, compared to the control group. Whereas, HM-B and HM-C group had increased level of ChAT compared to the control group. On the other hand, each experimental group did not show any significant difference to the level of serum AST/ALT and the weight ratio of the liver to the body. Conclusions This study provided evidences that the orally administered memory improvement herbal medication, and Moschus were effective to improve memory.

• YAKHAK HOEJI
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• v.49 no.5
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• pp.437-442
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• 2005

The purpose of this study was to characterize the putative anxiolytic-like effects of phenylpropanoids using the elevated plus maze (EPM) test in mice. Cinnamic acid, p-coumaric acid, caffeic acid and ferulic acid were orally administered to male ICR mice, 1 h before behavioral evaluation in an EPM, respectively. Control mice were treated with an equal volume of vehicle, and positive control mice diazepam (1 mg/kg). A single treatment with phenylpropanoids (at 8 mg/kg) significantly increased time-spent and arm entries into the open arms of the EPM, and decreased time-spent and arm entries into the closed arms of the EPM versus control (P<0.05). However, no changes in the locomotor activity and myorelaxant effect were seen in any group versus the saline control. These results suggest that phenylpropanoids may be an effective anx-iolytic agent.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.10
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• pp.853-858
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• 2016

Cooperation and collaboration with robots are key functions of robotic utility that are currently developing. Thus, robots should be safe and resemble human beings to cope with these needs. In particular, dual-arm robots that mimic human kinetics are becoming the focus of recent industrial robotics research. Their size is similar to the size of a human adult; however, they lack natural, human-like motion. One of the critical reasons for this is the shoulder complex. Most recent dual-arm robots have only 2 degrees of freedoms (DOFs), which significantly limits the workspace and mobility of the shoulders and arms. Therefore, a redundant shoulder complex could be very important in new developments that enable new capabilities. However, constructing a kinematically redundant shoulder complex is difficult because of spatial constraints. Therefore, we propose a novel, redundant shoulder complex for a human-like robot that is driven by flexible wire tendons. This kinematically redundant shoulder complex allows human-like robots to move more naturally because of redundant DOFs. To control the proposed shoulder complex, a hybrid control scheme is used. The positioning precision has also been considered, and the ability of the shoulder complex to perform several human-like motions has been verified.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.1
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• pp.101-107
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• 2001

The objective of this paper is to present a method for designing robust positioning control systems of a flexible arm using mixed $H_2/H_{\infty}$ and $\mu$ theory. We begin with a description of the flexible arm based on the model identification method and discuss the derivation of the model uncertainty. The validity of the obtained model is confirmed experimentally. Next, a robust controller is designed based on the mixed $H_2/H_{\infty}$ and $\mu$ theory by which we can improve robustness of the entire system. On this occasion, we also propose a general plant formation suitable to mixed $H_2/H_{\infty}$ control and $\mu$-theory. Finally, the effectiveness of the proposed design method is verified through experimentation.

• International Journal of Control, Automation, and Systems
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• v.3 no.3
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• pp.411-418
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• 2005

This paper discusses an output-tracking control design method for Takagi-Sugeno fuzzy systems with parametric uncertainties. We first represent the concerned system as a set of uncertain linear systems. The tracking problem is then converted into a stabilization problem thereby leading to a more feasible control design procedure. A sufficient condition for robust practical output tracking is derived in terms of a set of linear matrix inequalities. A numerical example for a flexible-joint robot-arm model has been demonstrated, to convincingly show effectiveness of the proposed system modeling and control design.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.04b
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• pp.218-222
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• 1993

A sliding mode controller associated with the moving sliding surface is formulate for the tip position control of a single-link flexible manipulator. After establishing the plant model which characterizes a noncollocated control system, a discontinuous control law is then constructed by restricting that velocity state variables are not available from direct sensor measurements. Using the proposed control law favorable system responses are accomplished through shortening the reaching phase without increasing maximum control torque. Furthermore, a low sensitiveness to extraneous disturbance is obtained. Computer simulations are undertaken in order to demonstrate these superior control performance characteristics to be accrued from the proposed methodology.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.6
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• pp.20-27
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• 1994

This paper presents a controller design to coordinate a robot manipulator under unknown system parameters and bounded disturbance inputs. To control the motion of the manipulator, an inverse dynamics control scheme is applied. Since parameters of the robot manipulators such as mass and inertia are not perfectly known, the difference between the actual and estimated parameters works as a disturbance force. To identify the unknown parameters, an improved adaptive control algorithm is directly derived from a chosen Lyapunov's function candidate based on the Lyapunov's Second Method. A robust control algorithm is devised to counteract the bounded disturbance inputs such as contact forces and disturbing forces coming from the difference between the actual and the estimated system parameters. Numerical examples are shown using three degree-of-freedom planar arm.