• Journal of Digital Convergence
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• v.11 no.2
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• pp.193-203
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• 2013

In our thesis we introduce case study for qualifying university graduates system for efficient maintenance. First, we find out factors to make maintenance difficult and present solution for them. Second, we convert system architecture from algorithm-oriented to driving-engine-based, design DB schema, develop algorithms for important components of proposed system, and implement them. Through results of system operation, we show that our system can reduce maintenance cost fairly.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.5
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• pp.55-61
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• 2005

In this paper, we propose the visual simulation system for virtual reality motion rider system. The visual simulation system can apply verity virtual reality system. This paper deals with programs on 3D automatic creation of terrain, road design, and a realtime rendering program for the virtual reality system. For the 3D automatic creation of terrain, DEM data and rectangular grid method are applied. We can make two different road object with the road design program. One of them includes road definition, and the other is obtained by using 'NURBS curve.' Visual simulation is consisted by additional modeling and real-time rendering. We can apply the programs made in this way to visual system of driving simulator.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.11
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• pp.5392-5395
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• 2013

Application of electric wheelchair, sort of wheelchair which is playing important role in transporting patients and old people, has been increasing. In this study, we designed the electric wheelchairs' driving system. Using the multi-step gear, the driving system can get great power, even though the small capacity of motors. First, we designed the multi-step gear, test its bending strength and contact strength, as well as verified its performance. We installed 'B-type electric brake(Multiple plate clutch, Anti-magnetization) in same axle of the driving system, so it is possible to stop under huge torque and small size. Using this driving system of the multi-step gear which we designed, it's possible to improve driving gear efficiency 30% up and create the high-competitive electric wheelchair. And, it is easy to repair and control.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.11
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• pp.1053-1059
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• 2007

This paper presents a target sate estimator(TSE) with low pass filter for improving the gun driving command. The ballistic computer uses target information such as predicted range, velocity, acceleration of a target to generate the gun command. We adopt the finite impulse response(FIR) filter as our TSE to shorten calculation time for the driving command and due to its inherent stability property. We also introduce a post-processing filter to reduce the high frequency components in the output signal of a TSE which may cause instability of gun driving. The first order low pass filter has been designed based on $H{\infty}$ criteria considering the noise characteristics. To show the validity of the present scheme, simulation results are given for the overall gun driving system including aircraft target information.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.390-392
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• 2013

In the paper, design and implementation results of the reference station software are described for the WA-DGNSS that is currently developed in pseudo-realtime concept. The reference software is designed and implemented by applying the object oriented methodology.

• Proceedings of the Korea Society for Simulation Conference
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• 2005.11a
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• pp.138-143
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• 2005

In order to reduce traffic accident, the interaction between drivers and roads should be studied in drivers' behaviour standpoints, and then this must be applied to the establishment of the road design standard. The K-ROADS(KICT-Road Analysis Driving Simulator) was developed to analyze and evaluate the road safety at the project HuRoSAS(Human & Road Safety Analysis System), since 2003. This has two distinct functions. One is the visual system which has 360 degree F.O.V. to reduce a dead angle on black spots as at-grade intersection. The other is the motion system which reproduce high frequency vibration made in irregular road surface and vehicle's motion. The K-ROADS has been used the study on the effect of alternatives of speed hump, and the study on the interior wall design of long tunnel to safety standpoints.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.2
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• pp.87-97
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• 2018

Bus, a major transportation mode, doesn't have a systematical evaluation system for dangerous driving behavior yet. This paper analyzes the characteristics and pattern of bus driving behavior using Digital Tacho Graph(DTG) data on express bus. 8 types of dangerous driving behavior were considered according to timeslot, the day of week and weather condition. As results, rapid acceleration, rapid left right turn and rapid deceleratio accounted for more than 97% and relatively high percentages were shown in dawn, on Friday and on the clear day, respectively. From the statistical analysis, correlation between the dangerous driving types and difference according the timeslot were found, and 3 groups considering the level of the dangerous driving were suggested. This study contributes to setting an efficient and reliable eduction system for using driving simulators.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.1
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• pp.52-58
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• 2014

To improve the performance of clutch actuator of clutch-by-wire system for commercial vehicles, it is necessary to understand the driving characteristics of the system. To explain and predict the effects of driving characteristics on clutch characteristics, AMESim software is used. The simulation model of clutch-by-wire system is developed in the AMESim environments under the geometrical dimensions and driving mechanisms of the clutch-by-wire system, such as the rotation speed of the DC motor, the gear ratio of the reducer, the design parameters of the release fork, the coefficient of the clutch diaphragm spring, and so on. The results show that the theoretical analysis of the clutch-by-wire system for commercial vehicles using the AMESim software find out the driving characteristics of the clutch actuator, and predict the performance characteristics of the clutch-by-wire system.

• Korean Journal of Computational Design and Engineering
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• v.3 no.1
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• pp.40-47
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• 1998

Recently, the various driving simulator have been used widely to analyze the handling performance of vehicle and to verify the motion control algorithm of vehicle. In this study, a virtual driving simulator based on the 20-DOF vehicle model is realized to estimate the handling performance and stability of a 4WS (Four-wheel-steering) and/or 4n(Four-wheel-driving) vehicle. Especially the DC motor controlled 4WS actuator is modelled in order to reflect the effect of the responsiveness of actuator on the handling performance and stability. And the realized simulator can be applied to develope a real time simulation system for designing and testing the real vehicles.

• Journal of Power System Engineering
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• v.14 no.3
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• pp.33-38
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• 2010

Technology of vehicle industry has been developing and it is required a better vehicle performance than before. Therefore, the consumers are asking not only an economic efficiency, functionality, polished design, ride comfort and silence but also a driving stability. The ride comfort, silence and driving stability are influenced by the size of vehicle and various facilities. But the principal factor is a room noise and vibration sensed by a driver and passenger. Thus, the NVH of vehicle has been raised and used as a principal factor for evaluation of vehicle performance. The primary objective of this study is an optimized design of powertrain mounting system. To optimized design was applied MSC.Nastran optimization modules. Results of dynamic analysis for powertrain mounting system was investigated. By theses results, design variables was applied 12 dynamic spring constant. And the weighting factor according to translational displacement and rotational displacement applied 3 cases. The objective function was applied to minimize displacement of powertrain. And the design variable constraint was imposed dynamic spring constant ratio. The constraint of design variable for objective function was imposed bounce displacement for powertrain.