• Journal of the Society of Disaster Information
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• v.5 no.1
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• pp.30-44
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• 2009

Asphalt concrete pavements are often destroyed within the intended design life due to the increasement in traffic volume. The most common types of asphalt concrete pavement damages are permanent deformation and fatigue cracking, and so on. In this research, characteristics of traffic loadings and lateral wheel path distributions are analyzed using the field survey on traffic flow. The obtained traffic characteristics can be used to the decision making for the maintenance policy of roads. According to the traffic lane analysis for the 2nd and 3rd lanes, inner lane vehicles tended to pass to the right side to avoid the opposite side vehicles. In addition, the outside lane vehicles were deviated to the left side to avoid passengers. It is also noted that the lateral wheel path distributions was close to the normal distribution.

• International Journal of Highway Engineering
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• v.16 no.1
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• pp.41-48
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• 2014

PURPOSES : The lane width of the domestic highway is 3.5 ~ 3.6m and it has been designed nationwide. However, the distribution of the average vehicle widths, rearview mirror widths and lateral wheel paths by region appear different. Then, lane spare widths may differ by region followingly. Thus, the flexible design of freeway lane widths is required. METHODS : The methodologies of this paper are as follows. First, vehicle widths rearview mirror widths lateral wheel paths of vehicles driven four national expressways were measured. Second, lane spare widths by vehicle widths were calculated. Third, lane spare widths reflecting rearview mirror widths were calculated by using interval estimation. Additionally, lane spare widths reflecting vehicles lateral wheel paths were calculated. RESULTS : The results of this paper are as follows. First, lane spare widths by vehicle widths ranges 0.83 to 0.95m. Second, lane spare widths reflecting rearview mirror widths ranges 0.518 to 0.747m at the confidence interval 95%. Third, lane spare widths reflecting vehicles' lateral wheel paths ranges -0.022 to 0.322m at the curved sections and the confidence interval 95%. CONCLUSIONS : It may be concluded that the present lane spare widths are relatively narrow at the curved section. Thus, there is a need to consider expanded lane widths at the curved sections. Additionally, there is a need to consider flexible design of lane widths by various conditions.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.6
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• pp.1229-1238
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• 2011

This paper deals with the lateral dynamic model of an all-wheel steered articulated vehicle to design a guidance controller. Nonlinear dynamic model of articulated vehicle is developed by complementing the model about the BRT system of California PATH in U. S. A. and the Phileas system of the APTS in Netherlands. Linear lateral dynamic model has been derived from the nonlinear dynamic model under some assumptions associated with the driving conditions. To design a guidance controller, we derive a transfer function that is steering angle as input and lateral acceleration as output from the linear lateral dynamic model by applying the parameter of vehicle that is developed by Korea Railroad Research Institute. To validate the dynamic model, nonlinear dynamic model has been compared with a vehicle model that has been programmed in ADAMS, and linear dynamic model has been compared with a nonlinear dynamic model under sime assumptions.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.2
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• pp.211-217
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• 2014

This paper addresses an algorithm of path planning for autonomous driving of a ground vehicle in waypoint navigation. The proposed algorithm is flexible in utilization under a large GPS positioning error and generates collision-free multiple paths while pursuing minimum traveling time. An optimal path reduces inefficient steering by minimizing lateral changes in generated waypoints along a path. Simulation results compare the proposed algorithm with the A* algorithm by manipulation of the steering wheel and traveling time, and show that the proposed algorithm realizes real-time obstacle avoidance by quick processing of path generation, and minimum time traveling by producing paths with small lateral changes while overcoming the very irregular positioning error from the GPS.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3D
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• pp.339-346
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• 2008

The research was conducted to investigate the characteristics of lateral wheel path distributions (wandering) in different traffic lanes. The lateral wheel path distributions may affect pavement life and various distress types. The results presented that the normal distribution curve with symmetry was observed in the 2-lane and 3-lane roads. In the case of the 2-lane road (on one direction), the wanderings were 70-95cm, and 70-85cm for the 1st and 2nd lanes, respectively, while in the case of the 3-lane road (on one direction), 50-60cm, 65-85cm, and 80-95cm for the 1st, 2nd, and 3rd lanes, respectively. In addition, the 1st lane vehicles tended to pass on the right side to avoid the opposite side vehicles, while the outside lane vehicles tended to pass on the left side to avoid the walkway.

• International Journal of Highway Engineering
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• v.10 no.3
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• pp.87-96
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• 2008

Wandering, variation of wheel tracks, has not been considered as an important factor for pavement designs and maintenance due to measuring difficulties. In order to investigate vehicle lateral displacements on roadways, this study measured wheel tracks on two-lane and four-lane National highways with lane widths 3.25m and 3.5m. The results showed that the tracks of left and right wheels were distributed into different forms, and those of left wheels were more concentrated. In the mean of the left distributions, 59.5cm and 80.7cm were obtained on lane widths 3.25m and 3.5m respectively by cars, and 58.4cm and 73.6cm were obtained by trucks. These mean differences seem to be generated from those between the lane widths. It is recommended to apply the distribution of left wheel tracks for pavement designs.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.2
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• pp.81-86
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• 2013

This paper presents the lane change system for collision avoidance. The proposed algorithm for the collision avoidance consists of path generation and path following. Using a calculated TTC (Time to Collision), partial braking is operated and collision avoidance path is generated considering relative distance, velocity and acceleration. Based on the collision avoidance path, desired yaw angle and yaw rate are calculated for the automated path following. The lateral controller is designed by a Lyapunov function approach using 3 D.O.F vehicle model and vehicle parameters. The required steering angle is determined from wheel velocity, longitudinal and lateral velocity in order to follow the desired yaw angle and yaw rate. This system is developed MATLAB/Simulink and its performance is evaluated using the commercial software CarSim.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.3
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• pp.209-219
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• 1997

A fuzzy driver model based on a preview-predictor and yaw rate is developed. The model is used to investigate the handling performance of two wheel steering system(2WS) and four wheel steering system(4WS) vehicles. The two degree-of- freedom model which has yaw and lateral motion predicts the path of the vehicles. Based upon the yaw rate and lateral deviations, the fuzzy engine describes the human driver's complicated control behavior which is adjusted for the driving environment. Both typical single lane change maneuver and double lane change maneuver are adopted to demonstrate the feasibility of fuzzy driver model.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.9
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• pp.761-767
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• 2005

There exists a structural limit of 2WS cars that drivers would not like simultaneously to follow the desired path and attenuate moments resulting from disturbances because lateral acceleration and yaw rate are coupled inherently. In order to overcome the limit, the 4WS cars that have rear wheel steering as an additional input have been introduced. But the 4WS cars have disadvantages that much cost is required due to structural alteration, it is difficult to be used to the driving circumstances and tire performances are not efficient in nonlinear or large lateral acceleration ranges. Therefore, it is proposed that, in this paper, a robust controller is easy to apply to 2WS cars by using direct yaw moment, decouples lateral acceleration from yaw motion and is robust against disturbances and uncertainties of system parameters, and thus the proposed control method has the advantages of 4WS cars which can be achieved in 2WS cars.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.1
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• pp.46-52
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• 2012

A PAEM(Pneumatic Active Engine Mount) system has been developed to improve NVH performance of a SUV in idle state. Control objective to attenuate the vibration of a vehicle should be determined prior to the design of control algorithm. This study presents the correlation analysis of output variables of PAEM system by means of TPA(Transfer Path Analysis) using experimental data obtained by vehicle test. The analysis results show that the vibration of vertical direction is more serious than those of longitudinal and lateral direction of the vehicle, and that the correlation between the vibration of front seat rail and that of steer wheel is highest. In conclusion, the vibrations of front seat rail and steer wheel in vertical direction should be considered as the control objectives of the PAEM.