• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.423-426
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• 1999

This paper describes a driving scheme of the series hybrid electric vehicle that we have developed. Both series HEV and parallel HEV are well known. We chose series HEV because it provides good energy efficiency in urban driving and operates in all-electric mode in performance. And engine-Generator is driven at constant speed with constant load to maintain the low emission. And the battery supplies power during high-load and receive energy during low-load

• Proceedings of the KIEE Conference
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• summer
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• pp.932-934
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• 2004

BLDC Motor is used in robots requiring a precisive motion recently. This paper presents the optimal design reducing the rotor inertia in order to improve the driving characteristic of BLDC motor driving robots, The optimal design was performed by using a parallel Genetic Algorithm which is superior at searching objective functions for the comflicated models having several optimal points. Therefore, objective function for optimization is rotor inertia and efficiency.

• The Journal of Korea Robotics Society
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• v.8 no.2
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• pp.116-128
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• 2013

This paper focuses on development of a testbed for analysis of robot-terrain interaction on rough terrain and also, through one wheel driving experiments using this testbed, prediction of maximum velocity and acceleration of UGV. Firstly, from the review regarding previous researches for terrain modeling, the main variables for measurement are determined. A testbed is developed to measure main variables related to robot-terrain interaction. Experiments are performed on three kinds of rough terrains (grass, gravel, and sand) and traction-slip curves are obtained using the data of the drawbar pull and slip ratio. Traction-slip curves are used to predict driving performance of UGV on rough terrain. Maximum velocity and acceleration of UGVs are predicted by the simple kinematics and dynamics model of two kinds of 4-wheel mobile robots. And also, driving efficiency of UGVs is predicted to reduce energy consumption while traversing rough terrains.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.3
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• pp.364-371
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• 2013

Because of the increases in international oil prices and the level of global warming, the automotive industry has much interest in developing green cars with high fuel efficiencies. In addition, researchers in Korea are actively responding to high oil prices and $CO_2$ emission regulations in many ways. One example is, the multi-mode hybrid system, which is being studied to improve its performance. Because a multi-mode hybrid system is able to overcome the weaknesses of a system that uses simple planetary gears, excellent fuel efficiency and driving performances are the key features of the system. This paper analyzes the driving performance of the power-train system of GM-2MT70, which consists of one engine, two electric motors, one simple planetary gear, one double planetary gear, two clutches, and two brakes. The driving performance of the system's steady state is analyzed using performance modeling. The dynamic performance is analyzed using Matlab Simulink.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.8
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• pp.1095-1100
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• 2013

Piezo devices have large power density and simple structure compared with conventional electrical motors. Thus they can generate larger forces than the conventional actuators with small size. Their resopnses to commands are also very fast and thus the bandwidths are very wide. Thus the piezo devices are expected to be used widely in the future for actuating devices requiring fast response and large actuating force with small size. However, the piezo actuators need high voltage with high driving current due to their large capacitive property. In this paper, proposed is a simple method to drive piezo devices using voltage inversion circuit with coli inductance. The coil inductance carries the charges in the piezo device to the opposite side, inverting the polarity of the applied voltage, thus saving the power to drive the device with AC voltages. Experiments with real circuit demonstrates that the proposed scheme can improve the energy efficiency very much.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.2
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• pp.292-300
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• 2009

This paper presents an LED BLU driving circuit with a local-dimming structure. The efficiency of the proposed LED driver has been improved by parallel driving 8 serial-connected LED arrays. It employed the soft-switching boost converter topology to reduce the switching power loss of the hard switching boost converter. Soft- and hard-switching converters have the same structure except that the free-wheeling diode in the hard-switching converter is replaced with the n-channel MOSFET in the soft-switching one. The proposed boost converter was compared with the hard switching converter. The soft-switching converter reveals superior ripple and efficiency. A smaller inductance can be used for the soft-switching converter contrasting to the hard-switching one. We also studied on an over-voltage protection circuit of the output of the driver at the no load condition. The protection circuit was applied to the proposed driver, and its operation was confirmed by experiment. Using a local-dimming technique, power consumption of LCD BLUs can be reduced as low as possible according to the brightness of its image.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.8
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• pp.19-23
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• 2005

The target of this research is a design of constant and high efficiency driving system for a low pressure UV lamp. An UV lamp system is one of wide range electrical equipments for semiconductor manufacturing and sterilization, etc... It is essential the technique of constant output for high added value device. A design target of driving system for low pressure UV lamp of conversion efficiency is 90[%], UV lamp of output stability within ${\pm}7.5[%]$, and lamp power is over 200[W]. The results meet the target of this study well, and have a benefit of domestic market occupation and enable to export. And if protection circuits were developed, it increases the stability of a electronic ballast for UV lamps.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.11
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• pp.5299-5320
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• 2019

Interest in self-driving vehicle research has been rapidly increasing, and related research has been continuously conducted. In such a fast-paced self-driving vehicle research area, the development of advanced technology for better convenience safety, and efficiency in road and transportation systems is expected. Here, we investigate research in self-driving vehicles and analyze the main technologies of driverless car software, including: technical aspects of autonomous vehicles, traffic infrastructure and its communications, research techniques with vision recognition, deep leaning algorithms, localization methods, existing problems, and future development directions. First, we introduce intelligent self-driving car and road infrastructure algorithms such as machine learning, image processing methods, and localizations. Second, we examine the intelligent technologies used in self-driving car projects, autonomous vehicles equipped with multiple sensors, and interactions with transport infrastructure. Finally, we highlight the future direction and challenges of self-driving vehicle transportation systems.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.11-19
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• 2004

When pile foundation constructed by driving method, it is desirable to perform monitoring and estimation of pile drivability and bearing capacity using some suitable tools. Dynamic Pile Monitoring yields information regarding the hammer, driving system, and pile and soil behaviour that can be used to confirm the assumptions of wave equation analysis. Dynamic Pile Monitoring is performed with the Pile Driving Analyser. The Pile Driving Analyser (PDA) uses wave propagation theory to compute numerous variables that fully describe the condition of the hammer-pile-soil system in real time, following each hammer impact. This approach allows immediate field verification of hammer performance, driving efficiency, and an estimate of pile capacity. The PDA has been used widely as a most effective control method of pile installations. A set of PDA test was performed at the site of Donghea-1 Gas Platform Jacket which is located east of Ulsan. The drilling core sediments of location of jacket subsoil are composed of mud and sand, silt. In this case study, the results of PDA test which was applied to measurement and estimation of large diameter open ended steel pipe pile driven by underwater hydraulic hammer, MHU-800S, at the marine sediments were summarized.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.261-265
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• 1997

Driving the electrodeless fluorescent lamp, the high ac voltage with high frequency is required. The linear power amplifier has been widely used as a driving circuit of electrodeless fluorescent lamp. However, the low efficiency of the power amplifier causes th driving circuit to be replaced by a PWM switching inverter. In order to use a PWM switching inverter as the driving circuit of an electrodeless fluorescent lamp, the high switching frequency is required. But due to the switching loss at switches of the inverter, the limitation of high switching frequency appears in the inverter. One solution to this limitation is to reduce the switching loss by using the zero voltage switching technique. In this paper, zero voltage switching resonant inverter for driving an electrodeless fluorescent lamp is discussed. The results of analysis about the inverter are presented and the equations for design are established. And the validity of the analyzed results are verified through the experiment.