• Structural Engineering and Mechanics
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• v.21 no.3
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• pp.369-374
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• 2005

A big progress has been made for moving force identification from bridge dynamic responses in recent years. Current knowledge and the potentials on moving force identification methods are reviewed in this paper under main headings below: background of moving force identification, experimental verification in laboratory and its application in field.

• Journal of Korean Society of Transportation
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• v.23 no.1
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• pp.83-92
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• 2005

This study if the first trial toward realizing a new methodology for vehicle re-identification based on heterogeneous sensor systems. A major interest of the author is how to effectively utilize information obtained from different sensors to derive accurate and reliable section travel times. The 'blade' sensor that is a newly developed sensor for capturing vehicle wheel information and the existing square loop sensor are employed to extract the inputs of the proposed vehicle re-identification algorithm. The fundamental idea of the algorithm developed in this study, which is so called 'anonumous vehicle re-identification,' it to match vehicle features obtained from both sensors. The results of the algorithm evaluation reveal that the proposed methodology could be successfully implemented in the field. The proposed methodology would be an invaluable tool for operating agencies in support of traffic monitoring systems and traveler information systems.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.6
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• pp.110-123
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• 2019

Traffic data is the most basic element necessary for transportation planning and traffic system operation. Recently, a method of estimating traffic flow characteristics using distance to a leading vehicle measured by an ADAS camera has been attempted. This study investigated the feasibility of the ADAS vehicle reflecting the distance error of image-based vehicle identification technology as a means to estimate the traffic flow through the normalized root mean square error (NRMSE) based on the number of lanes, traffic demand, penetration rate of probe vehicle, and time-space estimation area by employing the microscopic simulation model, VISSIM. As a result, the estimate of low density traffic flow (i.e., LOS A, LOS B) is unreliable due to the limitation of the maximum identification distance of ADAS camera. Although the reliability of the estimates can be improved if multiple lanes, high traffic demands, and high penetration rates are implemented, artificially raising the penetration rates is unrealistic. Their reliability can be improved by extending the time dimension of the estimation area as well, but the most influential one is the driving behavior of the ADAS vehicle. In conclusion, although it is not possible to accurately estimate the traffic flow with the ADAS camera, its applicability will be expanded by improving its performance and functions.

• Structural Engineering and Mechanics
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• v.29 no.2
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• pp.135-154
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• 2008

The moving vehicle loads on a bridge deck is one of the most important live loads of bridges. They should be understood, monitored and controlled before the bridge design as well as when the bridge is open for traffic. A MOM-based algorithm (MOMA) is proposed for identifying the timevarying moving vehicle loads from the responses of bridge deck in this paper. It aims at an acceptable solution to the ill-conditioning problem that often exists in the inverse problem of moving force identification. The moving vehicle loads are described as a combination of whole basis functions, such as orthogonal Legendre polynomials or Fourier series, and further estimated by solving the new system equations developed with the basis functions. A number of responses have been combined, some numerical simulations on single axle, two axle and multiple-axle loads, being either constant or timevarying, have been carried out and compared with the existing time domain method (TDM) in this paper. The illustrated results show that the MOMA has higher identification accuracy and robust noise immunity as well as producing an acceptable solution to ill-conditioning cases to some extent when it is used to identify the moving force from bridge responses.

• Journal of the Korea Society of Computer and Information
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• v.14 no.12
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• pp.201-208
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• 2009

As the ubiquitous environment is created, the latest ports introduce U-Port services in managing ports generally and embody container's location identification system, port terminal management system, and advanced information exchange system etc. In particular, the location identification system for freight cars and containers provide in real time the information on the location and condition for them, and enables them to cope with an efficient vehicle operation management and its related problems immediately. However, such a system is insufficient in effectively handling with the troubles in a large-scale port including freight car's disorderly driving, parking, stop, theft, damage, accident, trespassing and controlling. In order to solve these problems, this study structures the vehicle positioning system and the image verification system unsing high resolution image compression and AVE/H.264 store and transmission technology, able to mark and identify the vehicle location on the digital map while a freight car has stayed in a port since the entry of an automatic gate, or able to identify the place of accident through image remotely.

• Journal of Mechanical Science and Technology
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• v.16 no.10
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• pp.1253-1263
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• 2002

The control system design and modeling of an unmanned vehicle by means of a new concept for better performance through a tole-operation system is suggested by sensor fusion. But, the control of a real vehicle is very difficult, because the system identification of the vehicle is hard to find the unknown factors and the disturbances of the experimental environment. For the longitudinal and lateral controls, the traction system and steering system models are set up and a tuning method to find the gain of the controller by experiments is presented. In this research, mechanical and electronic parts are implemented to operate the unmanned vehicle and data reconstruction method of information about the environment data coming from several sensors is presented by data plot for the vehicle navigation. This paper focuses on the integration of tole-operated unmanned vehicle. This vehicle mainly controlled lateral and longitudinal directions with actuators for controlling vehicle movement and sensors for the closed-loop controlled system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.353-356
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• 2003

Acoustic holography is adopted in identifying the noise sources of a vehicle's underbody. Wind noise from a vehicle's underbody accounts for a large portion of the overall noise level due to the complex flow structure. Current study presents the development process of acoustic holography in the vehicle underbody, and discusses the results obtained using the method. Difficulties associated with using acoustic holography as well as the implication of the results regarding future noise reduction possibilities are discussed.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.909-910
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• 2006

In this paper, the transfer function to the vehicle is derived from using system identification algorithm in connection with the driving vehicle. We design the adaptive cruise controller using the derived transfer function, and make it possible to monitoring and control the vehicle in real time using embedded system and technology of Internet.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.2B
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• pp.107-118
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• 2009

In this paper, we present design and implementation for identification and location tracking techniques for vehicle information terminals in high-speed mobile environment using IEEE 802.11 wireless LAN technology. RSU be installed at a specific point. RSU recognizes it and then aware identification and location tracking for target vehicle when target vehicle that is equipped with information terminals pass near point. Issue of quick recognition using IEEE 802.11 access management frame, issue of weak wireless LAN security and tracking a range of restrictions be raised and we present solutions. Vehicle information terminal, RSU and a server-side GUI-based management program be implemented based on proposed solution. Implementation system be performed experiment at actual road environment and effectiveness be verified.

• Journal of Electrical Engineering and Technology
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• v.7 no.1
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• pp.132-140
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• 2012

A non-conservative robust Kalman filter (NCRKF) is applied to flight data to identify the aerodynamic derivatives of an unmanned autonomous vehicle (UAV). The NCRKF is formulated using UAV lateral motion data and then compared with results from the conventional Kalman filter (KF) and the recursive least square (RLS) method. A superior performance for the NCRKF is demonstrated by simulation and real flight data. The NCRKF is especially effective in large uncertainties in vehicle modeling and in measuring flight data. Thus, it is expected to be useful in missile and aircraft parameter identification.