scholarly journals Modeling and Analysis on Minimum Safe Distance for Platooning Vehicles Based on Field Test of Communication Delay

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Mengyan Hu ◽  
Xiangmo Zhao ◽  
Fei Hui ◽  
Bin Tian ◽  
Zhigang Xu ◽  
...  
Keyword(s):  
Traffic Safety ◽  
Field Tests ◽  
Transportation Systems ◽  
Communication Delay ◽  
Ieee 802.11P ◽  
Safe Distance ◽  
Automated Driving ◽  
Emergency Braking ◽  
The Impact ◽  
Minimum Safe Distance

Vehicle platooning is a perspective technique for intelligent transportation systems (ITS). Connected and automated vehicles (CAVs) use dedicated short-range communication (DSRC) to form a convoy, in which the following vehicles can receive the information from their preceding vehicles to achieve safe automated driving and maintain a short headway. Consequently, a vehicle platoon can improve traffic safety and efficiency, further reducing fuel consumption. However, emergency braking inevitably occurs when the platoon meets an accident or a sudden mechanical failure. It is more critical when the wireless communication got delays. Therefore, “how to predefine a minimum safe distance (MSD) considering communication delay” is a challenging issue. To this end, a series of field tests were carried out to measure the communication delay of IEEE 802.11p that is the underlying protocol of DSRC. Subsequently, MSD is modeled and analyzed when the platoon travels at accelerating, cruising, and decelerating states. More importantly, the results of field tests are applied in the models to investigate the impact of communication delay on MSD in practice. The simulation results verify that the proposed model can effectively maintain the platooning vehicles’ safety even if emergency braking happens with certain communication delays.

scholarly journals Impact of High-Altitude on Truck’s Climbing Speed: Case study in Qinghai-Tibet Plateau Area in China

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Tian Lei ◽  
Jinliang Xu ◽  
Xingli Jia ◽  
Leyu Wei ◽  
Lin Tian
Keyword(s):  
High Altitude ◽  
Traffic Safety ◽  
Field Tests ◽  
Tibet Plateau ◽  
Infrastructure Development ◽  
Plateau Area ◽  
Negative Effect ◽  
High Altitude Area ◽  
The Impact ◽  
Different Altitudes

Truck’s climbing performance is an important consideration in traffic safety, efficiency, and highway geometric design. With the infrastructure development in high-altitude area in China, more attention needs to be paid on truck’s climbing performance in such area. In this article, truck’s climbing speed in high-altitude area was examined through field tests on different grade sections at different altitudes. Truck’s speed-distance curves were built at different altitudes and the impact of altitude on truck’s climbing speed was explored based on the test results. It was shown that, within the altitude range of 3000~5000m, altitude had an obvious influence on test truck’s decelerating and accelerating performance. Truck’s speed decreased faster on steep grades and increased slower on gentle grades with the increase of the altitude. Also, the stable speed that test truck could maintain on a certain grade was lower at a higher altitude. In addition, test truck’s theoretical speed-distance curves at the sea level were estimated through truck’s dynamic model. Compared with the theoretical crawl speed, a negative effect of altitude change (from 0 to the altitude above 3000 m) was found on truck’s climbing performance.

scholarly journals Analysis of the advancements in real-life performance of highly automated vehicles' with regard to the road traffic safety

2018 ◽  
Vol 231 ◽  
pp. 05003 ◽  
Author(s):  
Arkadiusz Matysiak ◽  
Paula Razin
Keyword(s):  
Traffic Safety ◽  
Large Scale ◽  
Road Traffic ◽  
Real Life ◽  
Automated Vehicles ◽  
Automated Driving ◽  
The Road ◽  
Road Traffic Safety ◽  
On The Road ◽  
The Impact

The article presents the analysis of the performance of the vehicles equipped with automated driving systems (ADS) which were tested in real-life road conditions from 2015 to 2017 in the state of California. It aims at the effort to assess the impact on the road safety the continuous technological advancements in driving automation might have, based on of the first large-scale, real-life test deployments. Vehicle manufacturers and other stakeholders testing the highly automated vehicles in California are obliged to issue yearly reports which provide an insight on the test scale as well as the technology maturity. The so-called 'disengagement reports' highlight the range and number of control takeovers between the ADS and driver, which are made either based on driver's decision or information provided by the vehicle itself. The analysis of these reports allowed to investigate the development made in automated driving technology throughout the years of tests, as well as the direct or indirect influence of the external factors (e.g. various weather conditions) on the ADS performance. The results show that there is still a significant gap in reliability and safety between human drivers and highly automated vehicles which has been yet steadily decreasing due to technology advancements made while driving in the specific infrastructure and traffic conditions of California.

scholarly journals Toward an Intelligent Driving Behavior Adjustment Based on Legal Personalized Policies Within the Context of Connected Vehicles

2021 ◽  
Vol 7 ◽  
Author(s):  
Fatma Outay ◽  
Nafaa Jabeur ◽  
Hedi Haddad ◽  
Zied Bouyahia ◽  
Hana Gharrad
Keyword(s):  
Traffic Safety ◽  
Road Traffic ◽  
Self Regulation ◽  
Field Tests ◽  
Transportation Systems ◽  
Connected Vehicles ◽  
Consumer Privacy ◽  
Road Traffic Safety ◽  
Fair Competition ◽  
Driving Behaviors

The advent of Connected Vehicles (CVs) is creating new opportunities within the transportation sector. It is, indeed, expected to improve road traffic safety, enhance mobility, reduce fuel consumption and gas emissions, as well as foster economic growth via investments and jobs. However, to motivate the deployment of CVs and maximize their related benefits, policymakers must create appropriate neutral legal frameworks. These frameworks should promote the innovation of current road infrastructures, support cooperation and interoperability between transportation systems, and encourage fair competition between companies while upholding consumer privacy as well as data protection. We argue that policymakers should also support innovative mobility services toward a better accommodation of individual drivers and vehicles. Within this scope, we are proposing in this paper an intelligent approach that promotes the implementation of personalized road policies based on driving behaviors, driving performance, and the ongoing road traffic situation. These policies, which are dynamic in space and time, ultimately aim to increase drivers’ awareness by encouraging behavioral self-regulation. To meet our goals, we are using software agents that autonomously manage the driving behaviors according to well-defined transitions between driving states while enabling appropriate message exchanges between CVs. We run software simulations as well as field tests and obtained promising results that would reflect the relevance of implementing our vision of personalized policies.

scholarly journals An Empirical Study on V2X Enhanced Low-Cost GNSS Cooperative Positioning in Urban Environments

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5201 ◽  
Author(s):  
Paul Schwarzbach ◽  
Albrecht Michler ◽  
Paula Tauscher ◽  
Oliver Michler
Keyword(s):  
Empirical Study ◽  
Low Cost ◽  
Transportation Systems ◽  
Urban Environments ◽  
Position Estimation ◽  
Sensor Data ◽  
Ieee 802.11P ◽  
Traffic Information ◽  
Automated Driving ◽  
Cooperative Positioning

High-precision and lane selective position estimation is of fundamental importance for prospective advanced driver assistance systems (ADAS) and automated driving functions, as well as for traffic information and management processes in intelligent transportation systems (ITS). User and vehicle positioning is usually based on Global Navigation Satellite System (GNSS), which, as stand-alone positioning, does not meet the necessary requirements in terms of accuracy. Furthermore, the rise of connected driving offers various possibilities to enhance GNSS positioning by applying cooperative positioning (CP) methods. Utilizing only low-cost sensors, especially in urban environments, GNSS CP faces several demanding challenges. Therefore, this contribution presents an empirical study on how Vehicle-to-Everything (V2X) technologies can aid GNSS position estimation in urban environments, with the focus being solely on positioning performance instead of multi-sensor data fusion. The performance of CP utilizing common positioning approaches as well as CP integration in state-of-the-art Vehicular Ad-hoc Networks (VANET) is displayed and discussed. Additionally, a measurement campaign, providing a representational foundation for validating multiple CP methods using only consumer level and low-cost GNSS receivers, as well as commercially available IEEE 802.11p V2X communication modules in a typical urban environment is presented. Evaluating the algorithm’s performance, it is shown that CP approaches are less accurate compared to single positioning in the given environment. In order to investigate error influences, a skyview modelling seeking to identify non-line-of-sight (NLoS) effects using a 3D building model was performed. We found the position estimates to be less accurate in areas which are affected by NLoS effects such as multipath reception. Due to covariance propagation, the accuracy of CP approaches is decreased, calling for strategies for multipath detection and mitigation. In summary, this contribution will provide insights on integration, implementation strategies and accuracy performances, as well as drawbacks for local area, low-cost GNSS CP in urban environments.

scholarly journals Efficient Task Offloading for 802.11p-Based Cloud-Aware Mobile Fog Computing System in Vehicular Networks

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Qiong Wu ◽  
Hongmei Ge ◽  
Qiang Fan ◽  
Wei Yin ◽  
Bo Chang ◽  
...  
Keyword(s):  
Traffic Safety ◽  
Vehicular Networks ◽  
Fog Computing ◽  
Autonomous Driving ◽  
Computing System ◽  
Ieee 802.11P ◽  
Computational Capability ◽  
Markov Decision ◽  
The Impact ◽  
Task Offloading

Various emerging vehicular applications such as autonomous driving and safety early warning are used to improve the traffic safety and ensure passenger comfort. The completion of these applications necessitates significant computational resources to perform enormous latency-sensitive/nonlatency-sensitive and computation-intensive tasks. It is hard for vehicles to satisfy the computation requirements of these applications due to the limit computational capability of the on-board computer. To solve the problem, many works have proposed some efficient task offloading schemes in computing paradigms such as mobile fog computing (MFC) for the vehicular network. In the MFC, vehicles adopt the IEEE 802.11p protocol to transmit tasks. According to the IEEE 802.11p, tasks can be divided into high priority and low priority according to the delay requirements. However, no existing task offloading work takes into account the different priorities of tasks transmitted by different access categories (ACs) of IEEE 802.11p. In this paper, we propose an efficient task offloading strategy to maximize the long-term expected system reward in terms of reducing the executing time of tasks. Specifically, we jointly consider the impact of priorities of tasks transmitted by different ACs, mobility of vehicles, and the arrival/departure of computing tasks, and then transform the offloading problem into a semi-Markov decision process (SMDP) model. Afterwards, we adopt the relative value iterative algorithm to solve the SMDP model to find the optimal task offloading strategy. Finally, we evaluate the performance of the proposed scheme by extensive experiments. Numerical results indicate that the proposed offloading strategy performs well compared to the greedy algorithm.

scholarly journals Design of a Cooperative Lane Change Protocol for a Connected and Automated Vehicle Based on an Estimation of the Communication Delay

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3499 ◽  
Author(s):  
Hongil An ◽  
Jae-il Jung
Keyword(s):  
Traffic Safety ◽  
Communication Delay ◽  
Lane Change ◽  
Simulation Environment ◽  
Automated Vehicle ◽  
V2v Communication ◽  
Vehicle To Vehicle ◽  
Local Path ◽  
Set Up ◽  
The Impact

Connected and automated vehicles (CAVs) have recently attracted a great deal of attention. Various studies have been conducted to improve vehicle and traffic safety through vehicle to vehicle (V2V) communication. In the field of CAVs, lane change research is considered a very challenging subject. This paper presents a cooperative lane change protocol, considering the impact of V2V communication delay. When creating a path for a lane change in the local path planning module, V2V communication delay occurs. Each vehicle was represented, in our study, by an oriented bounding box (OBB) to determine the risk of collision. We set up a highway driving simulation environment and verified the improved protocol by implementing a longitudinal and lateral controller.

scholarly journals Electroencephalography Sample Entropy of Driver Passive Fatigue Threshold in Automated Driving

2021 ◽  
Author(s):  
Yijing Zhang ◽  
Jinfei Ma ◽  
Chi Zhang ◽  
Ruosong Chang
Keyword(s):  
Traffic Safety ◽  
Mental Workload ◽  
Fatigue Threshold ◽  
Automated Driving ◽  
Subjective Report ◽  
Low Load ◽  
Detection Response ◽  
Response Task ◽  
Stage 1 ◽  
The Impact

Abstract With the continuous improvement of automated vehicles, researchers have found that automated driving is more likely to cause insufficient mental workload for the driver, which induces passive fatigue and endangers traffic safety. To explore the impact of automation and scenario complexity on the passive fatigue of the driver, we developed a three-factor, 2 (automated driving, manual driving) × 2 (monotonic condition, engaging condition) × 6 (measurement stage: 1–6) mixed experiment. We collected electroencephalography (EEG), detection-response task (DRT) performance, and the subjective report scores of 48 drivers. We found that in automated driving under monotonic conditions, the topographic map’s activation range of the drivers brain was the smallest in the six stages, and the mental workload of this group continued to maintain the lowest state at each stage; however, the subjectively reported fatigue level was significantly increased; thus, the driver experienced passive fatigue. After simulating a low-load scenario for 40 min, the power of the alpha of the driver’s EEG indicators increased significantly, the accuracy of the detection reaction task decreased, and the reaction time became slower. The EEG sample’s entropy value of the driver’s passive fatigue was 0.243, and the judgement accuracy rate was 0.71. We proved that in automated driving under monotonic conditions, the driver is more prone to passive fatigue owing to insufficient mental workload.

scholarly journals PREREQUISITE FOR ACCIDENT-FREE TRAFFIC AT SIGNAL-CONTROLLED INTERSECTIONS

2021 ◽  
Vol 6 (1) ◽  
pp. 73-80
Author(s):  
Andrey Gorev ◽  
◽  
Olga Gasilova ◽  
Boris Sidorov ◽  
◽  
...  
Keyword(s):  
Traffic Safety ◽  
Traffic Accident ◽  
Traffic Accidents ◽  
Green Light ◽  
Traffic Intensity ◽  
Traffic Flows ◽  
Safe Distance ◽  
The City ◽  
Minimum Safe Distance ◽  
Maximum Intersection

Introduction: Improving intersection capacity will not be possible without accounting for traffic safety. Purpose of the study: We aim to determine the prerequisite for accident-free traffic at signal-controlled intersections with turning traffic flows. Methods: In our study, we used the methods of observation, comparison, and mathematical analysis. Results: We have carried out a field observation of traffic intensity at signal-controlled intersections in the city of Yekaterinburg, focusing on vehicles that moved when the green light was on. We have also analyzed traffic flow moving in three directions in the same lanes. We have discovered that traffic accident likelihood is the highest (54%) at four-way intersections. Three-way intersections account for 44% of traffic accidents, while the remaining 2% of accidents occur at multi-way intersections. Furthermore, we have determined the additional factors that impact safety in turning traffic flows at intersections. Our study demonstrates that in order to ensure maximum intersection capacity, the duration of the traffic signal cycle must be adjusted with the minimum safe distance between vehicles in mind.

scholarly journals Development of Test Equipment for Pedestrian-Automatic Emergency Braking Based on C-NCAP (2018)

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6206
Author(s):  
Zhiqiang Song ◽  
Libo Cao ◽  
Clifford C. Chou
Keyword(s):  
Control Method ◽  
Field Tests ◽  
Test Equipment ◽  
System Control ◽  
Automated Driving ◽  
Target Movement ◽  
Emergency Braking ◽  
Collaborative Control ◽  
Accuracy And Precision ◽  
Differential Positioning

In order to evaluate the effectiveness of a pedestrian-automatic emergency braking (PAEB) system on pedestrian protection, a set of PAEB test equipment was developed according to the test requirement of China-New Car Assessment Program (C-NCAP) (2018) in this study. In the aspect of system control strategy, global positioning system (GPS) differential positioning was used to achieve the required measurement and positioning accuracy, the collaborative control between the PAEB test equipment and automated driving robot (ADR) was achieved by wireless communication, and the motion state of the dummy target in the PAEB system was controlled by using the S-shaped-curve velocity control method. Part of the simulations and field tests were conducted according to the scenario requirements specified in C-NCAP (2018). The experimental and simulated results showed that the test equipment demonstrated high accuracy and precision in the process of testing, the dummy target movement was smooth and stable, complying with the requirements of PAEB tests set forth in C-NCAP (2018), and yielding satisfactory results as designed. Subsequently, the performance of the AEB of a vehicle under test (VUT) was conducted and the score for star-rating to evaluate the performance level of AEB calculated. Results indicated the developed test equipment in this study could be used to evaluate the performance of the PAEB system with effectiveness.

Case study: Prediction and field tests of railway noise and effects of a low-height noise barrier

2020 ◽  
Vol 68 (4) ◽  
pp. 303-314
Author(s):  
Yuna Park ◽  
Hyo-In Koh ◽  
University of Science and Technology, Transpo ◽  
University of Science and Technology, Transpo ◽  
University of Science and Technology, Transpo ◽  
...  
Keyword(s):  
High Speed ◽  
Field Tests ◽  
Residential Areas ◽  
Railway Systems ◽  
Railway Noise ◽  
Sound Levels ◽  
Noise Barrier ◽  
The Difference ◽  
Reduction Effect ◽  
The Impact

Railway noise is calculated to predict the impact of new or reconstructed railway tracks on nearby residential areas. The results are used to prepare adequate counter- measures, and the calculation results are directly related to the cost of the action plans. The calculated values were used to produce noise maps for each area of inter- est. The Schall 03 2012 is one of the most frequently used methods for the production of noise maps. The latest version was released in 2012 and uses various input para- meters associated with the latest rail vehicles and track systems in Germany. This version has not been sufficiently used in South Korea, and there is a lack of standard guidelines and a precise manual for Korean railway systems. Thus, it is not clear what input parameters will match specific local cases. This study investigates the modeling procedure for Korean railway systems and the differences between calcu- lated railway sound levels and measured values obtained using the Schall 03 2012 model. Depending on the location of sound receivers, the difference between the cal- culated and measured values was within approximately 4 dB for various train types. In the case of high-speed trains, the value was approximately 7 dB. A noise-reducing measure was also modeled. The noise reduction effect of a low-height noise barrier system was predicted and evaluated for operating railway sites within the frame- work of a national research project in Korea. The comparison of calculated and measured values showed differences within 2.5 dB.

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