scholarly journals Safety Evaluation of Flower Roundabout Considering Autonomous Vehicles Operation

2021 ◽  
Vol 13 (18) ◽  
pp. 10120
Author(s):  
Alessandro Severino ◽  
Giuseppina Pappalardo ◽  
Salvatore Curto ◽  
Salvatore Trubia ◽  
Isaac Oyeyemi Olayode
Keyword(s):  
Autonomous Vehicles ◽  
Safety Evaluation ◽  
Tail Length ◽  
Entry And Exit ◽  
Special Cases ◽  
Technological Growth ◽  
Micro Simulation ◽  
Safety Interventions ◽  
Dynamic Performances ◽  
Conclusion Section

With the significant technological growth that affected autonomous vehicles in the last decade, several consequences occurred as: human factor exclusion, entry and exit manoeuvres precision from roundabouts, and headway reduction. In this paper, it was carried out a microsimulation approach study that aims to evaluate benefits in terms of safety obtained with flower roundabouts in a scenario where traffic is characterized by conventional vehicles “CVs” and Connected Autonomous Vehicles “CAVs”. This study focused on the evaluation of CAVs and CVs operation with the presence of the so called “weak users” or rather, pedestrians and bikes. Then, simulated scenarios were characterized by the presence of zebra-crossings in main roads, positioned at 20 m from circulatory carriageway edges. Micro simulation choice is due to the absence of survey data collection because the presence of CAVs in ordinary traffic is still minimal. The micro simulation was carried out through VISSIM, so it was operated with a specific methodological path, consisting, in the application, of O–D matrix based on real cases, in order to achieve an assessment of potential conflicts in relation with the increase in CAVs. Simulation results showed that higher safety levels were achieved for special cases of O–D distribution and with CAVs present. Finally, considering crash absence in results related to CAVs presence, safety interventions of such roundabout types have to be thorough. There were 10 O/D matrices analysed through VISSIM considering parameters as: average tail length, maximum tail length, average speed, vehicles, and number of stops quantity. As reported in the conclusion section, O/D matrices that showed minimum conflicts and maximum dynamic performances were identified.

Autonomous Vehicles’ Car-Following Drivability Evaluation Based on Driving Behavior Spectrum Reference Model

2021 ◽  
pp. 036119812199485
Author(s):  
Xiao Qi ◽  
Ying Ni ◽  
Yiming Xu ◽  
Ye Tian ◽  
Junhua Wang ◽  
...  
Keyword(s):  
Autonomous Vehicles ◽  
Reference Model ◽  
Numerical Test ◽  
Safety Evaluation ◽  
Driving Behavior ◽  
Car Following ◽  
Driving Behaviors ◽  
Human Driver ◽  
Normal Human ◽  
Naturalistic Driving

A large portion of the accidents involving autonomous vehicles (AVs) are not caused by the functionality of AV, but rather because of human intervention, since AVs’ driving behavior was not properly understood by human drivers. Such misunderstanding leads to dangerous situations during interaction between AV and human-driven vehicle (HV). However, few researches considered HV-AV interaction safety in AV safety evaluation processes. One of the solutions is to let AV mimic a normal HV’s driving behavior so as to avoid misunderstanding to the most extent. Therefore, to evaluate the differences of driving behaviors between existing AV and HV is necessary. DRIVABILITY is defined in this study to characterize the similarity between AV’s driving behaviors and expected behaviors by human drivers. A driving behavior spectrum reference model built based on human drivers’ behaviors is proposed to evaluate AVs’ car-following drivability. The indicator of the desired reaction time (DRT) is proposed to characterize the car-following drivability. Relative entropy between the DRT distribution of AV and that of the entire human driver population are used to quantify the differences between driving behaviors. A human driver behavior spectrum was configured based on naturalistic driving data by human drivers collected in Shanghai, China. It is observed in the numerical test that amongst all three types of preset AVs in the well-received simulation package VTD, the brisk AV emulates a normal human driver to the most extent (ranking at 55th percentile), while the default AV and the comfortable AV rank at 35th and 8th percentile, respectively.

scholarly journals A Review of Car-Following Models and Modeling Tools for Human and Autonomous-Ready Driving Behaviors in Micro-Simulation

Smart Cities ◽  
2021 ◽  
Vol 4 (1) ◽  
pp. 314-335
Author(s):  
Hafiz Usman Ahmed ◽  
Ying Huang ◽  
Pan Lu
Keyword(s):  
Autonomous Vehicles ◽  
Adaptive Cruise Control ◽  
Cruise Control ◽  
Modeling Tools ◽  
Microscopic Traffic Simulation ◽  
Simulation Tools ◽  
Car Following ◽  
Driving Behaviors ◽  
Micro Simulation ◽  
Models And Modeling

The platform of a microscopic traffic simulation provides an opportunity to study the driving behavior of vehicles on a roadway system. Compared to traditional conventional cars with human drivers, the car-following behaviors of autonomous vehicles (AVs) and connected autonomous vehicles (CAVs) would be quite different and hence require additional modeling efforts. This paper presents a thorough review of the literature on the car-following models used in prevalent micro-simulation tools for vehicles with both human and robot drivers. Specifically, the car-following logics such as the Wiedemann model and adaptive cruise control technology were reviewed based on the vehicle’s dynamic behavior and driving environments. In addition, some of the more recent “AV-ready (autonomous vehicles ready) tools” in micro-simulation platforms are also discussed in this paper.

On the Dynamic Isotropy of Mechanisms With Two Degrees of Freedom

2005 ◽  
Author(s):  
Raffaele Di Gregorio ◽  
Alessandro Cammarata ◽  
Rosario Sinatra
Keyword(s):  
Finite Number ◽  
Degrees Of Freedom ◽  
Point Of View ◽  
Closed Curves ◽  
Special Cases ◽  
Dynamic Performances ◽  
Definition Of ◽  
Geometric Locus

The comparison of mechanisms with different topology or with different geometry, but with the same topology, is a necessary operation during the design of a machine sized for a given task. Therefore, tools that evaluate the dynamic performances of a mechanism are welcomed. This paper deals with the dynamic isotropy of 2-dof mechanisms starting from the definition introduced in a previous paper. In particular, starting from the condition that identifies the dynamically isotropic configurations, it shows that, provided some special cases are not considered, 2-dof mechanisms have at most a finite number of isotropic configurations. Moreover, it shows that, provided the dynamically isotropic configurations are excluded, the geometric locus of the configuration space that collects the points associated to configurations with the same dynamic isotropy is constituted by closed curves. This results will allow the classification of 2-dof mechanisms from the dynamic-isotropy point of view, and the definition of some methodologies for the characterization of the dynamic isotropy of these mechanisms. Finally, examples of applications of the obtained results will be given.

Improve environmental public health evaluation: connect outcome with process

2013 ◽  
Vol 56 (02) ◽  
pp. 54-58
Author(s):  
Anthony K. Mak ◽  
Jessica Ponto
Keyword(s):  
Public Health ◽  
Food Safety ◽  
Program Effectiveness ◽  
Safety Evaluation ◽  
Policy Makers ◽  
Environmental Public Health ◽  
Knowledge Based ◽  
Funding Program ◽  
Safety Strategies ◽  
Safety Interventions

The uptake of evidence-based public health has been swift; practitioners, policy-makers, funders, researchers, and the public are searching for evidence to validate public health program effectiveness for various reasons. To generate the needed evidence to support funding, program development, and policy making, some practitioners have started exploring evaluation of food safety strategies. Disappointedly, most of these studies or reviews have generated inconclusive evidence on the effectiveness of food safety interventions, despite the perceived public health benefits. Some reasons for failing to make succinct conclusions about these public health interventions include inappropriate methods, insufficient monitoring periods, narrow approaches, ignored processes, and insufficient data for interpretation. It is suggested that researchers conducting food safety evaluation must improve their evaluative methodology, publish more detailed findings, and disseminate knowledge based on guidelines set out in the Transparent Reporting of Evaluations with Nonrandomized Designs. Through improved details and transparency in publications, along with collaboration amongst inter-disciplinary practitioners, the utility of food safety strategies can be better demonstrated and translated. The same strategies can also be applied to the whole spectrum of environmental public health areas to achieve more innovative programs with clearer and more logical guided strategic changes.

scholarly journals New variational and multisymplectic formulations of the Euler–Poincaré equation on the Virasoro–Bott group using the inverse map

2018 ◽  
Vol 474 (2213) ◽  
pp. 20180052 ◽  
Author(s):  
Darryl D. Holm ◽  
Tomasz M. Tyranowski
Keyword(s):  
Variational Principle ◽  
Momentum Map ◽  
Soliton Equations ◽  
Special Cases ◽  
De Vries ◽  
New Type ◽  
Conclusion Section ◽  
Future Work ◽  
Nonlinearity Dispersion

We derive a new variational principle, leading to a new momentum map and a new multisymplectic formulation for a family of Euler–Poincaré equations defined on the Virasoro–Bott group, by using the inverse map (also called ‘back-to-labels’ map). This family contains as special cases the well-known Korteweg–de Vries, Camassa–Holm and Hunter–Saxton soliton equations. In the conclusion section, we sketch opportunities for future work that would apply the new Clebsch momentum map with 2-cocycles derived here to investigate a new type of interplay among nonlinearity, dispersion and noise.

scholarly journals Generalized proportional fractional integral functional bounds in Minkowski’s inequalities

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Tariq A. Aljaaidi ◽  
Deepak B. Pachpatte ◽  
Wasfi Shatanawi ◽  
Mohammed S. Abdo ◽  
Kamaleldin Abodayeh
Keyword(s):  
Integral Operator ◽  
Fractional Integral ◽  
Integral Functional ◽  
Fractional Integral Operator ◽  
Integral Inequalities ◽  
Special Cases ◽  
Close Relationship ◽  
Open Issue ◽  
Conclusion Section ◽  
Positive Functions

AbstractIn this research paper, we improve some fractional integral inequalities of Minkowski-type. Precisely, we use a proportional fractional integral operator with respect to another strictly increasing continuous function ψ. The functions used in this work are bounded by two positive functions to get reverse Minkowski inequalities in a new sense. Moreover, we introduce new fractional integral inequalities which have a close relationship to the reverse Minkowski-type inequalities via ψ-proportional fractional integral, then with the help of this fractional integral operator, we discuss some new special cases of reverse Minkowski-type inequalities through this work. An open issue is covered in the conclusion section to extend the current findings to be more general.

scholarly journals Safety Evaluation of Turbo-Roundabouts with and without Internal Traffic Separations Considering Autonomous Vehicles Operation

2021 ◽  
Vol 13 (16) ◽  
pp. 8810
Author(s):  
Tullio Giuffrè ◽  
Anna Granà ◽  
Salvatore Trubia
Keyword(s):  
Autonomous Vehicles ◽  
Safety Assessment ◽  
Safety Evaluation ◽  
Simulation Models ◽  
Safety Performance ◽  
Assessment Model ◽  
Crash Data ◽  
Vehicle Trajectories ◽  
Traffic Conflicts ◽  
Surrogate Measures

The paper presents a microsimulation approach for assessing the safety performance of turbo-roundabouts where Cooperative Autonomous Vehicles “CAVs” have been introduced into the traffic mix alongside conventional vehicles “CVs”. Based on the analysis of vehicle trajectories from VISSIM and subsequent analysis of traffic conflicts through the Surrogate Safety Assessment Model (SSAM), the research aims to evaluate the safety benefits of turbo-roundabouts where the lanes are physically separated by raised curbs, compared to roundabouts without such curbs. The paper will then describe the methodological path followed to build VISSIM models of turbo-roundabouts with and without raised curbs in order to calibrate the simulation models and estimate the potential conflicts when a higher percentage of CAVs are introduced into the traffic mix. A criterion has been also proposed for setting properly the principal SSAM filters. The results confirmed both higher safety levels for turbo-roundabouts equipped with raised lane dividers compared to turbo-roundabout solutions without curbs, and better safety conditions under the traffic mix of CVs and CAVs. Therefore, it follows that, in absence of crash data including CAVs, the surrogate measures of safety are the only approach in which the safety performance of any roundabout or road entity can be evaluated.

scholarly journals Safety Evaluation for Connected and Autonomous Vehicles’ Exclusive Lanes considering Penetrate Ratios and Impact of Trucks Using Surrogate Safety Measures

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Jian Zhang ◽  
Kunrun Wu ◽  
Min Cheng ◽  
Min Yang ◽  
Yang Cheng ◽  
...  
Keyword(s):  
Autonomous Vehicles ◽  
Autonomous Vehicle ◽  
Safety Evaluation ◽  
Driver Model ◽  
Microscopic Simulation ◽  
Safety Measures ◽  
Traffic Efficiency ◽  
Safety Improvement ◽  
Demand Scenario ◽  
Surrogate Safety Measures

Plenty of studies on exclusive lanes for Connected and Autonomous Vehicle (CAV) have been conducted recently about traffic efficiency and safety. However, most of the previous research studies neglected comprehensive consideration of the safety impact on different market penetration rates (MPRs) of CAVs, traffic demands, and proportion of trucks in mixture CAVs with human’s driven vehicle environment. On this basis, this study is to (1) identify the safety impact on exclusive lanes for CAVs under different MPRs with different traffic demands and (2) investigate the safety impact of trucks for CAV exclusive lanes on mixture environment. Based on the Intelligent Driver Model (IDM), a CAV platooning control algorithm is proposed for modeling the driving behaviors of CAVs. A calibrated 7-kilometer freeway section microscopic simulation environment is built by VISSIM. Four surrogate safety measures, including both longitudinal and lateral safety risk indexes, are employed to evaluate the overall safety impacts of setting exclusive lanes. Main results indicate that (1) setting one exclusive lane is capable to improve overall safety environment in low demand, and two exclusive lanes are more suitable for high-demand scenario; (2) existence of trucks worsens overall longitudinal safety environment, and improper setting of exclusive lanes in high trucks, low MPR scenario has adverse effect on longitudinal safety; and (3) setting exclusive lanes have better longitudinal and lateral safety improvement in high-truck proportion scenarios. Setting one or two exclusive lanes led to [+42.4% to −52.90%] and [+45.7% to −55.2%] of longitudinal risks while [−1.8% to −87.1%] and [−2.1% to −85.3%] of lateral conflicts compared with the base scenario, respectively. Results of this study provide useful insight for the setting of exclusive lanes for CAVs in a mixture environment.

scholarly journals Emission Effects of Cooperative Adaptive Cruise Control: A Simulation Case Using SUMO

10.29007/fbb7 ◽  
2019 ◽  
Author(s):  
İsmet Gökşad Erdağı ◽  
Mehmet Ali Silgu ◽  
Hilmi Berk Çelikoğlu
Keyword(s):  
Traffic Flow ◽  
Autonomous Vehicles ◽  
Cooperative Control ◽  
Simulation Environment ◽  
Cruise Control ◽  
Road Vehicles ◽  
Cooperative Adaptive Cruise Control ◽  
Simulation Based ◽  
Micro Simulation ◽  
Vehicular Traffic Flow

The recent advances in adaptive control and autonomous vehicles have given rise to the studies on cooperative control of road vehicles, and the consequent effects on traffic flow performances. In this paper, we summarize our findings from a simulation-based solution of a problem that seeks the joint optimization of a number of link-based performances of vehicular traffic flow considering explicitly the emissions exhausted using the Eclipse SUMO micro-simulation environment in order to discuss the effectiveness of the penetration rates of cooperatively controlled vehicles in mixed traffic.

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