• Journal of Advanced Marine Engineering and Technology
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• v.13 no.3
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• pp.26-36
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• 1989

Recently digital governor system is commonly adapted for the speed control of the marine diesel engine because of too much fluctuation of rpm resulted by the low speed, long stroke, high efficiency and a small number of cylinder of it, and versatile studies on the development of digital governor system are progressed. On this subject the new control method in which the fuel is controlled by feedforwarding the change of load as well as the feedback of angular velocity in case of disregarding the engine dead time and influence of scavenging air was proposed by the authors, and found the method has shown quite a good control performance in comparision to the conventional control method by the simulation using a digital computer for various load change. In this paper the speed control system of a diesel engine is simulated in case of regarding the engine dead time by the proposed method, and also confirm a good control performance of it under even more realistically simulated environment.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.4
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• pp.295-304
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• 2000

In the teleoperation system, force and velocity signals are communicated between a master and a slave robot. The addition of force feedback to a teleoperation system benefits the operator by providing more information to perform given tasks especially for tasks requiring contact with environment. When the master and slave arms are located in different places, time delay is unavoidable and it is well known that the system can become unstable when even a small time delay exists in the communication channel. The control scheme proposed in this paper is based on the estimator with virtual master model. Delayed signal from the master robot can be replaced by the estimated signal with the virtual master model. This control scheme makes the teleoperation system stable for the given time delay while the conventional scheme is not. This new control scheme is verified through numerical simulations and an experiments using the dual axis testbed of the teleoperation system.

• Proceedings of the IEEK Conference
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• 2002.06c
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• pp.37-40
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• 2002

Intelligent Wearable Module is intelligent system that arises when a human is part of the feedback loop of a computational process like a certain control system. Applied system is mobile robot. This paper represents the mobile robot control system remote controlled by Intelligent Wearable Module. So far, owing to the development of internet technologies, lots of remote control methods through internet have been proposed. To control a mobile robot through internet and guide it under unknown environment, We propose a control method activated by Intelligent Wearable Module. In a proposed system, PDA acts as a user interface to communicate with notebook as a controller of the mobile robot system using TCP/IP protocol, and the notebook controls the mobile robot system. Tlle information about the direction and velocity of the mobile robot feedbacks to the PDA and the PDA send new control method produced from the fuzzy inference engine.

• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.315-317
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• 2006

In addition to accurate position and velocity control, force control is necessary for a successful robot operation. In this paper, we have designed a simple robot gripper using a DC motor. For its force control, a current feedback control law is presented without using additional force sensors. Experimental results prove the effectiveness of the proposed control law. A digital controller is also developed with a TMS320LF2406 processor.

• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.504-509
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• 1990

This paper presents a decentralized adaptive control scheme for multi-Joint robot manipulators based on the independent joint control scheme. The control object is to achieve accurate tracking of desired Joint trajectories. The proposed control scheme does not use the complex manipulator dynamic model, and each joint is controlled simple by a feedback controller which ensure stable and also a position-velocity-acceleration feedforward controller and also auxiliary signal, with adjustable gains. Simulation results are given for a two-link manipulator under independent control, proposed decentralized adaptive control of manipulator is feasible. In spite of a pay load variation and strong static and dynamic couplings that exist between the joints.

• 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.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.2
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• pp.310-317
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• 2010

In this paper, we propose a method for swing-up and stabilization of a SESIP(Self-Erecting Single Inverted Pendulum) system which is one of the typical nonlinear systems. We use PV(Proportional velocity) controller for swinging up the pendulum and employ a PI-type state-feedback controller for stabilizing the pendulum. Control is switched to a stabilizing controller, which is designed to balance the inverted position of pendulum and the cart position to the near vertical position. Computer simulations are performed to illustrate the control performance of the proposed scheme.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.1
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• pp.93-100
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• 2018

This study proposes a controller that compensates torque error for precise angular velocity tracking and a method to compensate the stability of controller in implementation. Also, it is proved that the designed controller can be asymptotically stable based on Lyapunov stability theory. The proposed controller is able to control the d-axis reference current to arbitrary values and easily achieve control performance with two gains. As a result of applying to IPMSM of about 750W class, the steady state error with reference speed 1200 [RPM] is within 0.1 [%]. And it can be seen that it is an asymptomatic stable controller overcoming disturbance within about 0.2 second in application of constant load of about 5 [Nm].

• Journal of Ocean Engineering and Technology
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• v.27 no.6
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• pp.56-64
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• 2013

Crabbing motion is the pure sway motion of a ship without surge velocity. Thus, it can be applied to a berthing operation. Crabbing motion is induced by a peculiar operation method called the push-pull mode. The push-pull mode is induced by using a combination of the main propeller and side thruster. Two propellers generating the same amounts of thrust and rotating in opposite directions produce some yawing moment on a vessel but do not induce longitudinal motion. With the additional operation of side thrusters, the push-pull mode is used to induce a large amount of lateral force. In this paper, three-degree-of-freedom equations of motion such as for the surge, sway, and yaw are constructed for the crabbing motion. Based on these equations of motion, a feedback linearization control method is applied to auto-berthing control for a twin-screw ship with side thrusters. The controller can deal with the nonlinearity of a system, which is present in the berthing maneuver of a twin screw ship. A simulation of the auto-berthing of a ship is performed to validate the performance of the designed controller.

• International Journal of Automotive Technology
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• v.7 no.4
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• pp.449-457
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• 2006

The driver model during drift cornering was examined, and a technique to improve vehicle movement performance during drift cornering was investigated. Based on the results obtained, the driver was found to steer using feedback of the body slip angle and the body slip angle velocity during drift cornering. Moreover, improvement of the cornering force characteristic, at which exceeded the maximum cornering force calm as much as possible is important.