• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.173-174
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• 2015

If a wind speed decreases during inertial control of a wind turbine generator (WTG), the rotor speed might decrease below the minimum operating limit, which is called over-deceleration (OD). When OD occurs, inertial control should be disabled and then the output power of a WTG significantly decreases. This significant power reduction causes a subsequent frequency drop. This paper proposes the stepwise inertial control to prevent OD when a wind speed decreases during inertial control. To do this, the proposed scheme changes the additional power output based on the rotor speed. The performance of the proposed scheme is investigated using an EMTP-RV simulator. The results show that the proposed inertial control scheme prevent OD even when the wind speed decreases during inertial control.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 전력전자학술대회 논문집
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• pp.352-356
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• 1998

This paper is a study about Ac servo motor position and speed control characteristics which depend on feedforward control, the acceleration / deceleration time constant after the interpolation, and PI control, automatic deceleration at corner in order to shape cutting control of feed drive system of the machine tool. The shape error caused by delay of the servo system in the direction of radius at the time of circular cutting is reduced by feedforward control. The shape error generated by the position command delay is minimized by using the acceleration / deceleration time constant after the interpolation. The results were verified to optical machining center experimentation of the machine tool.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.671-677
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• 1996

This paper proposes a study on the effects of motion errors for acceleration/ deceleration types. The proposed motion errors are consisted of two errors : one due to transient response of servomechanism and the other due to gain mismatching of positioning servo motor. They are derived from using laplace transformation for the block diagram of general purpose feed drive system. In order to minimize them, the paper proposes second order polynomial regression model by using orthogonal array method which describes one of experimental methodolgies. The validity and reliability of the study was veri lied on a vertical machining center equipped with FANUC 0MC through a series of experiments and analyses.

• 한국자동차공학회논문집
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• 제9권2호
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• pp.152-167
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• 2001

Recently safety systems for the commercial vehicle have been rapidly developed. However, we still have many problems in the vehicle stability and the braking performance. Especially, a commercial vehicle may meet a dangerous braking condition when the vehicle is lightly loaded or empty and when the road is wet or slippery. Under these conditions, the truck can spin out or the tractor can jackknife or the trailer can swing out. To design the air brake system for the commercial vehicle, since the air brake system has many design variables, there must have been intensive researches on a method how to prevent dynamic instability and how to maximize the vehicle deceleration. In this study, mathematical models about the tractor-semitrailer and the air brake system including an ABS controller have been constructed for computer simulation. Also, simple examples are applied to show the usefulness of the program. Designers can use this simulation program for understanding the braking characteristics such as trajectory, braking distance, longitudinal deceleration, lateral deceleration, and yaw rate on various road conditions.

• 한국군사과학기술학회지
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• 제16권1호
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• pp.89-94
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• 2013

Electro Otical Tracking System(EOTS) is required for a rapid movement as well as the stabilization of Line-Of-Sight(LOS). In order to achieve these two goals, this paper presents a position and velocity driving profile generation method from the constant acceleration and deceleration profile according to the current state, enabling a fast and smooth trajectory even if the target position changes during the movement of LOS. Simulation and experimental results reveal that the settling time could be reduced significantly by adopting the present position control scheme.

• 한국전기전자재료학회논문지
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• 제16권3호
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• pp.175-180
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• 2003

As the integrated circuit device shrinks to the deep submicron regime, the ion implantation process with high ion dose has been attracted beyond the conventional ion implantation technology. In particular, for the case of boron ion implantation with low energy and high dose, the stabilization and throughput of semiconductor chip manufacturing are decreasing because of trouble due to the machine conditions and beam turning of ion implanter system. In this paper, we focused to the improved characteristics of processing conditions of ion implantation equipment through the modified deceleration mode. Thus, our modified recipe with low energy and high ion dose can be directly apply in the semiconductor manufacturing process without any degradation of stability and throughput.

• 대한전기학회논문지:전력기술부문A
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• 제48권3호
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• pp.304-312
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• 1999

In order to make industrial robots and CNC machine tools perform tasks efficiently, each axis has to be accelearated and decelerated appropriately. The existing techniques for the acceleration and deceleration of industrial robots and CNC machine tools are not efficient to generate velocity profiles. Thus, these previous techniques cannot generate velocity generating velocity profiles that cannot be generated by them. Based on the proposed approach, an acceleration and deceleration circuit for industrial robots and CNC machine tools is designed with a FPGA by using the VHDL.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 A
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• pp.391-394
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• 1993

The acceleration/deceleration control method and interpolated operating are essential to the servo motor control system. In a few years ago, a floating point DSP chip was used for the purpose of processing a lot of calculated amount. But in this paper, we proposed new acceleration/deceleration control method and circular interpolation algorithm without another floating point DSP chip. The validity of proposed algorithms are verified through computer simulation and experimental result.

• 한국정밀공학회지
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• 제33권9호
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• pp.745-751
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• 2016

This paper presents the acceleration and deceleration control of free-form surfaces. A rapid variation of acceleration (or Deceleration) drives the system into a machine shock, resulting in the inaccuracy of the path control of the NURBS curve. The pattern of acceleration control can be established using the curvature of the NURBS curve. The curvature can be easily calculated from the first and second derivative of the NURBS curve used in Taylor's expansion for NURBS interpolation. However, the derivatives are not used in the recursive method for NURBS interpolation. Hence, we attempted the difference-derivatives for calculating the NURBS curvature. Both, Taylor's expansion and the recursive method, are used jointly for controlling the acceleration in the same interpolation algorithm.

• International Journal of Naval Architecture and Ocean Engineering
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• 제13권1호
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• pp.877-888
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• 2021

The water entry behaviors of projectiles with different cone-headed angles were studied numerically, experimentally and theoretically, mainly focusing on the hydrodynamic impact in the initial stage. Based on MMALE algorithm, it was proposed a formula of impact deceleration, which relied on the initial entry velocity and cone-headed angle. Meanwhile, in order to verify the validity of the simulation model, experiments using accelerometer and high-speed camera were carried out, and their results were in a good agreement with simulation results. Also, theoretical calculation results of cavity diameter were compared with experiments and simulation results. It was observed that the simulation method had a good reliability, which would make forecast on impact deceleration in an engineering project.