• 제어로봇시스템학회:학술대회논문집
• /
• 1999.10a
• /
• pp.25-28
• /
• 1999

In this article, a new performance index is proposed to re-duce the collision impulsive force by controlling the null motion of redundant manipulators. First, we define the normalized impact ellipsoid in the viewpoint of instantaneous velocity change. Then, we propose a new impact performance index based on velocity direction for null motion to reduce initial impulsive effects. It gives some advantage for the case of unknown environment. The optimization of this index is that the successional impact forces are reduced. The performance of the proposed index is demonstrated by simulation study.

• 제어로봇시스템학회:학술대회논문집
• /
• 1986.10a
• /
• pp.49-54
• /
• 1986

In this paper we deal with a method of controlling PUMA 560 robot manipulator using a newly developed optical proximity sensor and the PDP-11/44 computer. The sensor output is different somewhat depending on an color of the object. The range of sensing vary from 38.4mm to 109.5mm for a real object, 39mm to 111.65mm for yellow, and 40.55mm to 107.25mm for blue. When an obstacle is encountered on the path of end-effector the system acknowledger immediatly the existence of the obstacle : and holds the motion of arm at a given distance. And also the system is capable of making the end effector avoid the obstacle automatically and keep on its motion.

• Journal of KSNVE
• /
• v.9 no.1
• /
• pp.33-41
• /
• 1999

This paper presents a method of actively controlling the interior noise by a trim panel with hybrid feedforward-feedback control loop. The control technique is designed to minimize the vibration of panel whose motion is limited to that of a piston (out-of-plane motion). The hybrid controller consists of an adaptive feedforward controller in conjunction with a linear quadratic Gaussian (LQG) feedback controller. In order to maintain control performance of both persistent and transient disturbances, the feedback loop speeds up the adaptation rate of feedforward controller by improving damping capacity of secondary plant related with the adaptation rule. Numerical simulation and experimental result indicate that the hybrid controller is a more effective method for reducing the vibration of the panel (and therefore the interior noise) compared to using feedforward controller.

• Proceedings of the KSME Conference
• /
• 2000.11a
• /
• pp.535-540
• /
• 2000

This paper presents the development of a Parallel-Typed CNC Machining Tool. It is specially designed to machine a complex shaped workpiece by controlling the orientation of the tool. The inverse/direct kinematics of a parallel mechanism is derived and implemented in a PC based controller. With graphics icons, the GUI (Graphic User Interface) program is developed for the CNC programing. The calibration is accomplished by geometric constraint motion, which is a parallel motion of the platform with respect to a table. The calibration result is introduced and the future study is proposed.

• Proceedings of the KIPE Conference
• /
• 1998.10a
• /
• pp.119-124
• /
• 1998

This paper proposes a new repulsive-Maglev vehicle in which a vertical type PM linear synchronous motor (LSM) can levitate and propel simultaneously, independently of the vehicle speeds. A compact control method is developed which is based on the concept of controlling individually the levitation system by armature-current and the propulsion system by mechanical load-angle. The levitation-motion control experiments have carried out successfully together with positioning at standstill. The pitching motion has been compensated for very well by using the zero-phase-current control method proposed here.

• Proceedings of the KIPE Conference
• /
• 2002.07a
• /
• pp.677-680
• /
• 2002

The biggest obstacle in utilizing Telerobotics is that an exclusive line is necessary to connect the distant place and manipulator for the purpose of remote control. Moreover, installment of an exclusive line Is limited to relatively short distance, as the installment entails more difficulties with longer distance and increasing installment cost. The purpose of this paper is to suggest a methodology of factory automation by using Lab VIEW to control and monitor actuators, which are the basis of controlling manipulators, form distant places.

• Proceedings of the KIEE Conference
• /
• 1997.07a
• /
• pp.130-132
• /
• 1997

In this paper, we propose a new type of tubular linear induction motor(TLIM) with two-dimensional motion. The proposed motor consists of four short primary LIMs arranged on a same circumference and a common secondary. By adopting independently energized ring-windings to the primary, we can expect the reduction of coil-end region and the freedom of alternating current supply. The secondary conductor is capable of producing anyone of rotary, linear, and helical motions by controlling the phase of supply currents in each primary winding. From the 3-D finite element analysis and the experiment, we derive the feeding conditions to increase the subsidiary rotary-force and an optimal arrangement of primary currents to reduce the number of slot.

• Proceedings of the KIEE Conference
• /
• 2000.07d
• /
• pp.3216-3218
• /
• 2000

Projection-type Fast Spin Echo (PFSE) imaging has robustness against motion artifacts due to patient motion during magnetic resonance imaging data acquisition, or reduce flow artifacts. However, it has difficulty in controlling T2 contrast. In this paper, T2 contrast in the PFSE method is analyzed. The contrasts in FSE and PFSE method are compared by computer simulation and experiments with volunteers.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.8 no.4
• /
• pp.409-421
• /
• 2016

Container ships are prone to move at a greater speed compared to other merchant ships. The slenderness of the hull of container vessel is for better speed, but it leads to unfavorable motions. The pitch and roll are related and sometimes the vessel might be forced to parametric roll condition which is very dangerous. A fin attached to the ship hull proves to be more efficient in controlling the pitch. The fin is fitted at a lowest possible location of the hull surface and it is at the bow part of the ship. Simulations are done using proven software package ANSYS AQWA and the results are compared. Simulations are done for both regular and irregular seas and the effect of fin on ship motion is studied. P-M spectrum is considered for various sea states.

• Structural Engineering and Mechanics
• /
• v.51 no.5
• /
• pp.743-754
• /
• 2014

Investigations of regular and chaotic vibrations of the autoparametric pendulum absorber suspended on a nonlinear coil spring and a magnetorheological damper are presented in the paper. Application of a semi-active damper allows controlling the dangerous motion without stooping of system and additionally gives new possibilities for designers. The investigations are curried out close to the main parametric resonance. Obtained numerical and experimental results show that the semi-active suspension may reduce dangerous motion and it also allows to maintain the pendulum at a given attractor or to jump to another one. Moreover, the results show that, for some parameters, MR damping may transit to chaotic motions.