• Title/Summary/Keyword: Autonomous vehicles

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Vehicle Steering System Analysis for Enhanced Path Tracking of Autonomous Vehicles (자율주행 경로 추종 성능 개선을 위한 차량 조향 시스템 특성 분석)

  • Kim, Changhee;Lee, Dongpil;Yi, Kyongsu
    • Journal of Auto-vehicle Safety Association
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    • v.12 no.2
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    • pp.27-32
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    • 2020
  • This paper presents steering system requirements to ensure the stabilized lateral control of autonomous driving vehicles. The two main objectives of a lateral controller in autonomous vehicles are maintenance of vehicle stability and tracking of the desired path. Even if the desired steering angle is immediately determined by the upper level controller, the overall controller performance is greatly influenced by the specification of steering system actuators. Since one of the major inescapable traits that affects controller performance is the time delay of the steering actuator, our work is mainly focused on finding adequate parameters of high level control algorithm to compensate these response characteristics and guarantee vehicle stability. Actual vehicle steering angle response was obtained with Electric Power Steering (EPS) actuator test subject to various longitudinal velocity. Steering input and output response analysis was performed via MATLAB system identification toolbox. The use of system identification is advantageous since the transfer function of the system is conveniently obtained compared with methods that require actual mathematical modeling of the system. Simulation results of full vehicle model suggest that the obtained tuning parameter yields reduced oscillation and lateral error compared with other cases, thus enhancing path tracking performance.

A Study on the Acceptance Intention of Autonomous Vehicle- Focusing on the Moderating Effect of Consumer Knowledge (자율주행 자동차의 수용의도에 관한 연구- 소비자 지식의 조절효과를 중심으로)

  • Cho, Sang Lee;Bae, Jin Hyun;Jeong, Seok Chan
    • The Journal of Information Systems
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    • v.30 no.4
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    • pp.95-118
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    • 2021
  • Purpose This study verified the moderating effect of consumer knowledge in relation to the factors affecting the acceptance intention of autonomous vehicles by adding trust to the United Theory of Acceptance and Use of Technology model for the commercialization of autonomous vehicles. Design/methodology/approach For this purpose, this study conducted a survey on general consumers who are interested in automobiles. A total of 250 questionnaires were distributed and collected, and 242 questionnaires were used for analysis. To test the hypotheses, multiple regression analysis and multiple group analysis were performed. Findings Performance expectations, effort expectations, social influence, and trust were found to have a positive effect on the acceptance intention of autonomous vehicles. In addition, consumer knowledge between performance expectation and acceptance intention and between effort expectation and acceptance intention was confirmed as a variable that can moderate the relationship.

A study on road damage detection for safe driving of autonomous vehicles based on OpenCV and CNN

  • Lee, Sang-Hyun
    • International Journal of Internet, Broadcasting and Communication
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    • v.14 no.2
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    • pp.47-54
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    • 2022
  • For safe driving of autonomous vehicles, road damage detection is very important to lower the potential risk. In order to ensure safety while an autonomous vehicle is driving on the road, technology that can cope with various obstacles is required. Among them, technology that recognizes static obstacles such as poor road conditions as well as dynamic obstacles that may be encountered while driving, such as crosswalks, manholes, hollows, and speed bumps, is a priority. In this paper, we propose a method to extract similarity of images and find damaged road images using OpenCV image processing and CNN algorithm. To implement this, we trained a CNN model using 280 training datasheets and 70 test datasheets out of 350 image data. As a result of training, the object recognition processing speed and recognition speed of 100 images were tested, and the average processing speed was 45.9 ms, the average recognition speed was 66.78 ms, and the average object accuracy was 92%. In the future, it is expected that the driving safety of autonomous vehicles will be improved by using technology that detects road obstacles encountered while driving.

Modeling and Analysis of IGLAD Traffic Accident Case using Prescan for SOTIF Standard Development (SOTIF 표준 개발을 위한 Prescan 기반 IGLAD 교통사고 케이스 모델링 및 분석)

  • Sangjoong Kim;Dongha Shim
    • Journal of Auto-vehicle Safety Association
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    • v.15 no.3
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    • pp.53-58
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    • 2023
  • Defects in the vehicle itself were considered the biggest risk factor for traffic accidents as the electrical and electronic components of vehicles, which were not there before, increase. Therefore, the vehicles have been developed based on ISO 26262 (an international functional safety standard) which is focusing on functional defect safety evaluation of electrical and electronic component systems. However, in the future, as autonomous driving technology is applied, even vehicles without functional defects must be prepared for the dangerous traffic situation that may arise from exceptional or external factors. SOTIF (Safety Of The Intended Functionality) is a concept to prevent exceptional or external factors. The main objective of SOTIF is to decrease Unknown & Unsafe factors as much as possible by finding Known factors and Unsafe factors. In this study, Prescan provided SIEMENS, one of the autonomous driving simulators, is used to make scenarios of IGLAD traffic accident cases. From the simulation results, Unsafe & Safe cases were classified and analyzed to derive unsafe factors.

Development of Collision Prevention Usage Scenario based on Vehicle-to-Vehicle Communication of Autonomous Vehicles (자율주행 차량의 차량 대 차량 통신에 기반한 충돌방지 활용 시나리오 개발)

  • Seo, HyunDuk;Kwon, Doyoung;Shin, Jaemin;Choi, Eunhyuk;Lim, Huhnkuk
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.26 no.2
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    • pp.251-257
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    • 2022
  • Self-driving vehicles are a type of smart vehicle with the help of ICT technology, which means a vehicle that operates without the intervention of a driver.Vehicles with vehicle safety communication technology (V2X) applied use information detected from various sensors or other vehicles/infrastructures to enable the smart vehicle to accurately and quickly predict the driver's potential danger situation, contributing to more stable autonomous driving. In this paper, among V2X communication technologies, a vehicle-to-vehicle communication (V2V) simulation communication technology is used to present a scenario for preventing collisions in autonomous vehicles. A vehicle collision prevention system based on V2V simulated communication was implemented and the suggested collision prevention application scenario was demonstrated. The suggested collision prevention utilization scenario can be considered as one application case of V2V communication technologies that are currently being developed/applied.

The Development Trend Analysis of Autonomous Driving Technology for Unmanned Ground Combat Vehicles (지상무인전투차량 자율주행 기술 동향분석 및 발전방향)

  • Lee, Jin-Ho;Kim, Seok;Lee, Cheon-Soo
    • Journal of the Korea Institute of Military Science and Technology
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    • v.14 no.5
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    • pp.760-767
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    • 2011
  • To strategically select the technology priority based on the understanding of technology development trends and prospects is very important. To provide such guidance for autonomous driving technology in unmanned ground combat vehicles, this report deals with followings; 1) The core technologies for autonomous driving are reviewed. 2) And domestic and foreign policies for relevant technology development are investigated. 3) Then, to estimate the technology development trend, the published patents and research papers are analyzed. 4) Based on those analyses, domestic technology level and development prospects are expected.

Flow Interaction of Sailing Drone using Numerical Method

  • Ngoc, Pham Minh;Choi, Min-Seon;Yang, Changjo
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2019.11a
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    • pp.230-232
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    • 2019
  • There is an accelerating need for ocean sensing where autonomous vehicles can play a key role in assisting engineers, researcher and scientists with environmental monitoring and collecting oceanographic data. This paper is performed to develops an autonomous sailing drone to be used as a sensor carrying platform for autonomous data acquisition at Sea. From a sailing drone design viewpoint, it is important to establish reliable prediction methods for sailing drone's resistance. The required power for the propulsion unit depends on the ship resistance and speed. There are three solutions for the prediction of ship resistance as follow analytical methods, model tests in tanks and Computational Fluid Dynamics (CFD). The present paper aims at simulating sailing drone friction resistance using numerical method. The dynamic mesh motion is used to describe the sailing drone movement.

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Comparative analysis of activation functions within reinforcement learning for autonomous vehicles merging onto highways

  • Dongcheul Lee;Janise McNair
    • International Journal of Internet, Broadcasting and Communication
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    • v.16 no.1
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    • pp.63-71
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    • 2024
  • Deep reinforcement learning (RL) significantly influences autonomous vehicle development by optimizing decision-making and adaptation to complex driving environments through simulation-based training. In deep RL, an activation function is used, and various activation functions have been proposed, but their performance varies greatly depending on the application environment. Therefore, finding the optimal activation function according to the environment is important for effective learning. In this paper, we analyzed nine commonly used activation functions for RL to compare and evaluate which activation function is most effective when using deep RL for autonomous vehicles to learn highway merging. To do this, we built a performance evaluation environment and compared the average reward of each activation function. The results showed that the highest reward was achieved using Mish, and the lowest using SELU. The difference in reward between the two activation functions was 10.3%.

Changes in air pollutant emissions from road vehicles due to autonomous driving technology: A conceptual modeling approach

  • Hwang, Ha;Song, Chang-Keun
    • Environmental Engineering Research
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    • v.25 no.3
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    • pp.366-373
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    • 2020
  • The autonomous vehicles (AVs) could make a positive or negative impact on reducing mobile emissions. This study investigated the changes of mobile emissions that could be caused by large-scale adoption of AVs. The factors of road capacity increase and speed limit increase impacts were simulated using a conceptual modeling approach that combines a hypothetical speed-emission function and a traffic demand model using a virtual transportation network. The simulation results show that road capacity increase impact is significant in decreasing mobile emissions until the market share of AVs is less than 80%. If the road capacity increases by 100%, the mobile emissions will decrease by about 30%. On the other hand, driving speed limit increase impact is significant in increasing mobile emissions, and the environmentally desirable speed limit was found at around 95 km/h. If the speed limit increases to 140 km/h, the mobile emissions will increase by about 25%. This is because some vehicles begin to bypass the congested routes at high speeds as speed limit increases. Based on the simulation results, it is clear that the vehicle platooning technology implemented at reasonable speed limit is one of the AV technologies that are encouraging from the environmental point of view.

Hazard Analysis of Autonomous Vehicle due to V2I Malfunction (V2I 오작동에 의한 자율주행자동차의 위험성 분석)

  • Ahn, Dae-ryong;Shin, Seong-geun;Baek, Yun-soek;Lee, Hyuck-kee
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.18 no.6
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    • pp.251-261
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    • 2019
  • The importance of autonomous driving systems that utilize V2X services such as V2V(Vehicle to Vehicle) and V2I(Vehicle to Infrastructure) for safer and more comfortable driving is increasing with the recent development of autonomous vehicles. Partly autonomous vehicles based on environmental sensors have limitations for predicting and determining areas beyond the recognition distance of the mounted sensors and in response to atypical objects that are difficult to detect. Therefore, it is important to utilize the V2X service to improve the limit of sensor detection performance and to make driving safer and more comfortable. However, there may be an accident risk of autonomous vehicles due to incorrect information provided by V2X. Thus, the application of technology to prevent this needs to be considered. In this pater, we used the ISO-26262 Part3 Process and performed HARA (Hazard Analysis and Risk Assessment) to derive the risk sources of autonomous vehicles due to V2I malfunctions by using the communication between vehicles and infrastructure among V2X. We also developed ASIL ratings based on the simulations and real vehicle tests of the malfunctions of major cases of usnig V2I.