• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.6
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• pp.37-45
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• 2011

As vehicles become more intelligent, in-vehicle networking (IVN) systems such as controller area network (CAN) or FlexRay are essential for convenience and safety of drivers. To expand the applicability of IVN systems, attention is currently being focused on the communication between heterogeneous networks such as body networking and chassis networking systems. A gateway based on message mapping method was developed to interconnect FlexRay and CAN networks. However, this type of gateways has the following shortcomings. First, when a message ID was changed, the gateway must be reloaded with a new mapping table reflecting the change. Second, if the number of messages to be transferred between two networks increase, software complexity of gateway increases very rapidly. In order to overcome these disadvantages, this paper presents FlexRay-CAN gateway based on node mapping method. More specifically, this paper presents a node mapping based FlexRay-CAN gateway operation algorithm along with the experimental evaluation for ID change.

• Journal of Drive and Control
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• v.18 no.4
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• pp.9-18
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• 2021

This study proposes a method for creating learning datasets to recognize obstacles using deep learning algorithms in automated construction machinery or an autonomous vehicle. Recently, many researchers and engineers have developed various recognition algorithms based on deep learning following an increase in computing power. In particular, the image classification technology and image segmentation technology represent deep learning recognition algorithms. They are used to identify obstacles that interfere with the driving situation of an autonomous vehicle. Therefore, various organizations and companies have started distributing open datasets, but there is a remote possibility that they will perfectly match the user's desired environment. In this study, we created an interface of the virtual simulator such that users can easily create their desired training dataset. In addition, the customized dataset was further advanced by using the RDBMS system, and the recognition rate was improved.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.10
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• pp.1359-1366
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• 2010

Recently, many electronic control techniques for vehicles have been developed and applied. One of the technologies can be X-by-wire such as throttle-by-wire, brake-by-wire, steer-by-wire, and etc, in which most of mechanical parts are replaced into electrical wire and actuators. In this study, the effect of throttle-by-wire and brake-by-wire control systems on vehicle velocity control, especially in a school zone, are taken into consideration. The number of accidents reported in school zones is higher than that in other places. The reason for this is that many vehicle drivers do not obey speed limit regulations. Moreover, some of the students are careless while crossing the streets. Therefore, in this study, we attempt to develop a method using throttle-by-wire and brake-by-wire control systems for automatically reducing the vehicle speed such that it will be within the speed limit. First, an engine model and a transmission system model are developed for a specific vehicle model. Second, speed reduction is carried out such that the reduction follows a pre-designed cubic spline trajectory; the trajectory is determined such that rapid deceleration, which causes discomfort to the driver and passengers, can be prevented, for which a fuzzy-PID control algorithm is applied for the trajectory following control. Finally, simulation results are presented to verify the performance of the proposed speed reduction control system.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.6
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• pp.90-100
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• 2017

The purpose of this study is to detect and label the vehicles using the drone images as a way to overcome the limitation of the existing point and section detection system and vehicle gap estimation on Arterial road. In order to select the appropriate time zone, position, and altitude for the acquisition of the drone image data, the final image data was acquired by shooting under various conditions. The vehicle was detected by applying mixed Gaussian, image binarization and morphology among various image analysis techniques, and the vehicle was labeled by applying Kalman filter. As a result of the labeling rate analysis, it was confirmed that the vehicle labeling rate is 65% by detecting 185 out of 285 vehicles. The gap was calculated by pixel unitization, and the results were verified through comparison and analysis with Daum maps. As a result, the gap error was less than 5m and the mean error was 1.67m with the preceding vehicle and 1.1m with the following vehicle. The gaps estimated in this study can be used as the density of the urban roads and the criteria for judging the service level.

• Journal of Ocean Engineering and Technology
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• v.30 no.1
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• pp.32-43
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• 2016

A UUV needs to have a robust path following performance because of unpredicted current disturbances. Because the desired path of a UUV is usually designed by considering the locations of obstacles or geographical features of the operation region, the UUV should stay on the desired path to avoid damage or loss of the vehicle. However, conventional path following methods cannot deal with strong countercurrent disturbances. Thus, the UUV may deviate from the desired path. In order to avoid such deviation, a backward path following method is suggested. This paper proposes a path following method that combines pure pursuit guidance and nonlinear guidance for the UUV under an unpredicted strong ocean current. For a stable path following system, this paper suggests that the UUV adjust its heading to the current direction using the pure pursuit guidance method when the system is in an unstable region, or the UUV follows the desired path with nonlinear guidance. By combining the pure pursuit guidance and nonlinear guidance, it was possible to overcome the drawbacks of each path following method in the reverse path following case. The efficiency of the proposed method is shown through simulation results compared to those of the pure pursuit method and nonlinear guidance method.

• Journal of Pharmaceutical Investigation
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• v.28 no.3
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• pp.141-149
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• 1998

In order to reduce systemic side effects following administration, flurbiprofen was formulated as O/W microemulsion consisting of the surfactant, oil phase and aqueous phase. Particle size distribution, apparent viscosity, solubility and skin permeation of flurbiprofen in various vehicles and microemulsion were evaluated. The domain of O/W microemulsion s phase diagram had difference between oil types and the area of O/W microemulsion was wide distributed by adding to PG and cosurfactant than that of water alone. As increasing 10, 15 and 20% of Brij 97 content and 1, 2.5, 5% of oil content, the solubility of flurbiprofen in O/W microemulsions and various vehicles was $400{\sim}1,000$ and $10{\sim}500$ times higher than that of control. Also, apparent viscosity of soybean oil microemulsions was higher than that of IPM microemulsions and that of vehicle were increased as increasing vehicle content. Since skin permeation of flurbiprofen decreased as increasing viscosity, in each vehicle, it was not affected 2% ${\beta}-CD$ and decreased as increasing PG content and to 2, 5 and 10% of $HP-{\beta}-CD$. In O/W microemulsion, 5% soybean oil. 20% Brij 97 and 75% water(A-1) with high viscosity showed low skin penetration.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.3
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• pp.1229-1235
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• 2014

At the LPG vehicle air intake system, most of dust particles in the air cleaner are removed. However very small particles are not removed and accumulated. The accumulation of carbon in air intake system is going to affect the idle speed control and sensor signal. It also causes engine chattering and transmission troubles of automatic transmission. This is study about cleaning up intake system using cleaning chemical. We can clean up the intake system by spraying cleaning liquid onto intake device when the engine is idling after intake hose is removed from warmed up vehicle. We can obtain the following experimental results by cleaning up ISC, surge tank, intake manifold, intake valves and combustion chamber. According to this results, the stroll valve works correctly and power rate of engine is up to the standard, it is smoothy to control the idling speed when a vehicle pulls up. After cleaning up CO grow down about 0.15%, HC does about 20~100 ppm.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.3
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• pp.250-256
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• 2014

EV(Electric Vehicle) has many benefits such as prevention of global warming and so on. But due to driving source changing from combustion engine to battery and e-motor, new R&D difficulties have arisen which changing of desired vehicle performance and multidisciplinary design constraints by means of strong coupled multi-physics domain problems. Additionally, dynamics performances of EV becomes more important due to increasing customer's demands and expectations for EV in compare with internal combustion engine vehicle. In this paper suggests model based development platform of EV through integrated simulation environment for improving analyse & design accuracy in order to solve multi-physics problem. This simulation environment is integrated by three following specialized simulation tools IPG CarMaker, AVL Cruise, DYMOLA that adapted to each purpose. Furthermore, control algorithm of TV(Torque Vectoring) system is developed using independent driven e-motor at rear wheels for improving handling performance of EV. TV control algorithm and its improved vehicle performances are evaluated by numerical simulation from standard test methods.

• Journal of Aerospace System Engineering
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• v.13 no.3
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• pp.64-69
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• 2019

The purpose of this study is to explore the current status and challenges of the space development system in Korea following the successful launch of test vehicle, the Korean space launch vehicle II on the 30th anniversary of space development and seek an alternative to the government organizations for efficient space development future. The study investigates the space development system of leading countries such as USA, France, and Japan with keen focus on the administrative organizations and thereafter draw implications for Korea. The analysis of the existing situation in Korea focuses on governance, such as space-related government organizations, space development agency, and specialized research funding agency. As a result, this study proposes the need for full-scale discussion on building a space agency.

• International Journal of Highway Engineering
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• v.14 no.2
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• pp.93-99
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• 2012

This study analyzes traffic data which are collected by VDS(Vehicle Detection System) to research the relationship between spacing distribution and vehicles' relative speed. The collected data are relative speed between preceding and following vehicles, passing time and speed. They are also classified by lane and direction. For the result of the analysis, in the same platoon, we figure out that mean of spacing is 40m, which can be a value to determine section A to D. To compare spacing according to time interval, this study splits time intervals to peak hour and non-peak hour by peak hour traffic volume. In conclusion, vehicles in peak hour are in car following because most drive similar speed as preceding vehicle and they have relatively small spacing. On the other hand, non-peak hour's spacing between vehicles is bigger than that of peak hour. This implies driver's behaviors that the less spacing, the more aggressive and want to reduce their travel time in peak hour, whereas most drive easily in non-peak hour and recreational trip purpose because of less time pressure.