• Journal of Drive and Control
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• v.12 no.2
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• pp.14-20
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• 2015

This paper focuses on the issue of force synchronizing control for the injection servomechanism of injection molding machines. Prior to the controller design, a virtual design model was developed for the injection mechanism with an AC servomotor-ball screw. A synchronizing controller is designed and combined with the PID control to accommodate the mismatches between the real plant and the linear model plant used. Due to the plant uncertainty, the stiffness and the damping of the mechanism were considered. From the tracking control simulations based on the virtual design model, it is shown that a significant reduction in force synchronizing error is achieved through the use of a proposed control scheme.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.5
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• pp.729-737
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• 2009

This paper introduces the machine tools feed system, which can be optimized the control's performance through simulation and the adjustment of the mechanical components. One method simulates the frequency response of the speed-loop with the design value using the MATLAB application, so that all of the interpolation axis can be equal to the response bandwidth, resulting in a high accuracy rate. The other method sees the mechanical component being adjusted by analyzing the results of various experiments. Lastly, this client's program is able to change the parameters that are related to the FFD, as well as the parameters in the friction compensation of the OPEN-CNC.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.12
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• pp.1049-1054
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• 2015

Nowadays, there are many researches involving structural actuators, which have adjustable stiffness; they are also called variable stiffness actuators (VSA). The VSAs can adjust the characteristics of actuators for various functions and human-machine safety. This paper describes the design and analysis of two types of VSAs. To adjust stiffness, the actuators are controlled by a principle of lever ratio mechanism, by changing a pivot position or a spring position in the structure with springs. To make the principle workable, the designs are simplified by using a ball screw system with a motor. Each structure shows different static properties with variable rates of stiffness. We have also shown the experimental verification of the dynamic performance of the two types of VSAs. This research can be applied to various industrial fields, where humans work in conjunction with robots.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.3
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• pp.71-79
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• 2008

In this paper the glass inspection system for the thickness and flatness is implemented. Laser sensors and robot arms required for glass measurements is tested on the performance assesment. Three kinds of laser sensors are used and analysed, and 3-axis robot arm with the ball-screwed type is implemented. Thus the methods of glass measurement is discussed and the difficulties are solved to propose the solutions. To minimize the errors of glass measurement the system is improved as considered device errors.

• Journal of the Korea Organic Resources Recycling Association
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• v.22 no.4
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• pp.28-44
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• 2014

Due to development of the national economy growth, livestock goods consumption has rapidly increased over the past 30 years. It has led livestock breeders to increase their livestock numbers. An increased number of livestock have consequently resulted in an increasing animal feces generation. According to the agricultural statistics provided by the Bureau of Statistics, livestock manure amounts to 47,235 thousand tons in 2013. To treat livestock manure, various types of treatment facilities like composting, liquid fertilization, purification, and anaerobic digestion facilities are being applied. In composting facility, there are four kinds of agitation system: escalator, paddle, screw and rotary type. In case of liquid fertilization process, there are two types of system: aeration and anoxic type. There are about 8,000 liquid fertilization facilities for treatment livestock manure in Korea. For purification of livestock manure, the treatment process is divided by three steps: Solid/Liquid separation process, Secondary purification process and advanced oxidation process. About 21 thousand tons of livestock manure was treated by anaerobic digestion facility in 2012. In every type of facility for livestock manure treatment, it is very important to choose the optimal deodorization equipment for the livestock manure treatment facility. In this study, the investigation has been carried out for six years to analyse the characteristics of livestock manure treatment facilities and related technique of Korea.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.4
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• pp.47-53
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• 2011

The Electric Multiple Unit (EMU) has many types of door system such as sliding door, plug door etc.al. according to customer's requirements. The sliding door is widely used in Korea but has weak point in the noise problem. In the low operation speed, the noise coming from outer side of the EMU is not an important factor. As the speed is higher than before, noise is increased and make a problem. The main cause of noise is the imperfect air tightness in the EMU. The plug door system has advantages for the noise reduction characteristic in the high speed area. We have been developing electric plug-in door. The door is controlled by Door Control Unit(DCU) following the order of Automatic Train Protection (ATP) that is a kind of train signalling system. DCU has to simultaneously open and close the doors and the operation of it is related to the passengers safety. So DCU is a safety device that is important to reliability and safety. DCU is composed of several devices of control, motor driving, Input/Output, communication and power. In this paper, we will describe the functions, characteristic, requirement, subsystem and test results of DCU used for the electric plug-in door.