• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.437-441
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• 1995

In this paper, the ultra precision positioning system for servo motor and piezo actuator using dual servo loop control has been developed. For positioning system having long distance with ultra precision, the combination of global stage and micro stage is required. Servo moter and ball screw are used as a master stage and piezo acuator as a fine stage. By using this system, an positional precision witin .+-. 30nm has been achieved at dual servo loop control. When using micro stage, an positional precision within .+-. 10nm has been achieved. This result can be applied to develop semiconductor equipment such as wafer stepper.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.836-841
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• 2002

This paper is concerned with the development of remote control and measurement systems system using the internet. Recently, various techniques are developed based on the advance of the internet environment. In this study, we developed the remote control and measurement system using the internet server programming technique, stepper motor control and the data acquistion programming techniques. Hence, we can perform measurement and control remotely. The feasibility of the system is validated using the experimental setup. A personal computer is equipped with the stepping motor controller which control the weight and the A/D board which measures the strain of the beam, server program was then installed on the PC and can be accessed through internet.

• Journal of Electrical Engineering and Technology
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• v.6 no.5
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• pp.640-646
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• 2011

The current study presents the design and performance of a novel 4/2 switched reluctance motor (SRM) for a high-speed air blower. With a comparative study of some rotor structures for a high-speed drive, a stepper-type rotor is optimized to produce a continuous torque and a low torque ripple. Rotor pole arc is modified to have a wide continuous output torque region, and air gap is determined to develop less torque ripple. The rotor radius is determined to reduce torque ripple with a reiterative FEM analysis. The designed rotor has three regions: short uniform, long uniform, and nonuniform air-gap region. The positive torque region is wider than a conventional 4/2 SRM without any torque dead zone. A prototype is tested and the efficiency is up to 72[%] at 30,000[rpm], 600[w] output.

• International Journal of Advanced Culture Technology
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• v.8 no.3
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• pp.260-268
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• 2020

Currently, it is usually a 3D scanner processing method as a laser method. However, the laser method has a disadvantage of slow scanning speed and poor precision. Although optical scanners are used as a method to compensate for these shortcomings, optical scanners are closely related to the distance and precision of the object, and have the disadvantage of being expensive. In this paper, 3D scanner using variable focus lens-based structured light module with improved measurement precision was designed to be high performance, low price, and usable in industrial fields. To this end, designed a telecentric optical system based on a variable focus lens and connected to the telecentric mechanism of the step motor and lens to adjust the focus of the variable lens. Designed a connection structure with optimized scalability of hardware circuits that configures a stepper motor to form a system with a built-in processor. In addition, by applying an algorithm that can simultaneously acquire high-resolution texture image and depth information and apply image synthesis technology and GPU-based high-speed structured light processing technology, it is also stable for changes to external light. We will designed and implemented for further improving high measurement precision.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1186-1189
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• 2004

A new pump used in arthroscopy surgery was developed. The pump is driven by pneumatic air compressor and controlled by a stepper motor connected to an air regulator. Pressure control performance was observed to be similar compared to commercially available artheroscopy pumps. However, pressure pulses observed in the commercial pumps driven by multiple rollers disappeared in the pneumatically driven pump. The new pump required containers to enclose and squeeze saline solution packs. A dramatic saving in manufacture cost is expected considering the simple pneumatic drive used in this pump.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.3
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• pp.23-31
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• 2005

The purpose of this study is to design a disturbance observer for a micro-stepping stage to eliminate the disturbances from cables, friction, mass unbalance of the moving part, etc. The disturbance observer is designed for air-floating X-Y precision micro-stepping X-Y stage which widely used in stepper machine or semiconductor manufacturing systems. The micro-stepping X-Y stage has a weak point of the variation of characteristics with position locations, which caused by various disturbances. In this study, it will be described that a simple and high throughput disturbance observer algorithm improves the dynamic error and settling time of the micro-stepping stage.

• Journal of Mechanical Science and Technology
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• v.16 no.9
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• pp.1166-1174
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• 2002

This paper presents the implementation and vehicle tests of a vehicle longitudinal control scheme for Stop and Go cruise control. The control scheme consists of a vehicle-to-vehicle distance control algorithm and throttle/brake control algorithm for acceleration tracking. The desired acceleration of a vehicle for vehicle-to-vehicle distance control has been designed using Linear Quadratic optimal control theory. Performance of the control algorithm has been investigated via vehicle tests. A millimeter wave radar sensor has been used for distance measurement. A stepper motor and an electronic vacuum booster have been used for throttle/brake actuators, respectively. It has been shown that the proposed control algorithm can provide satisfactory performance.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.6
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• pp.72-81
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• 1999

A nonlinear engine torque and speed control algorithm using throttle angle control is developed with an engine load torque estimation algorithm. Three 3-dimensional nonlinear engine maps as a part of the nonlinear control algorithm are obtained from steady state engine dynamometer tests. An electric throttle actuator is developed using a stepper motor and a 8 bit micro-processor. The speed control and external load estimation algorithm are tested via engine speed control experiments, and show performance good enough for using various engine torque and speed control applications.

• Journal of Energy Engineering
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• v.24 no.3
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• pp.34-39
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• 2015

Recently, Air pollution is gradually increasing which are coming from the exhaust of the ICE vehicles in the world. ICE vehicle exhaust gas and $CO_2$ are widely suspected of contributing to the called greenhouse effect, fueling fears of global warming. Therefore, many countries are striving to decrease the vehicle exhaust gas and have developed a variety of policies as air pollution regulation plans. To comply with the regulations, automotive industry has developed hybrid vehicles, which have features of both ICE vehicles and electric vehicles. Hybrid car is eco-friendly and has lowered exhausting gases and improved fuel efficiency. This research has been written to show that break down cases with EGR valve in hybrid cars, steadily increasing in use, and to help with on-site maintenance.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.12
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• pp.2187-2195
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• 1997

A semi-active suspension test system was designed and built for the experimental study. Vehicle parameters were estimated through tests and a quarter-car model was validated by comparing computer simulation results and laboratory test results. Alternative semi-active suspension control laws have been tested using the test system. Modulable damper used in this study is a "reverse" damper with 42 states which is controlled by a stepper motor. Experimental results have shown that semi-active suspensions have potential to improve ride quality of automobiles.tomobiles.