scholarly journals SUSTAINABILITY EFFECTS OF NEXT-GENERATION INTERSECTION CONTROL FOR AUTONOMOUS VEHICLES

Transport ◽  
2015 ◽  
Vol 30 (3) ◽  
pp. 342-352 ◽  
Author(s):  
Zhixia (Richard) Li ◽  
Madhav V. Chitturi ◽  
Lang Yu ◽  
Andrea R. Bill ◽  
David A. Noyce
Keyword(s):  
Energy Consumption ◽  
Autonomous Vehicles ◽  
High Volume ◽  
Ambient Air ◽  
Next Generation ◽  
Pm 2.5 ◽  
Time Space ◽  
Moderate Volume ◽  
Vehicle Technologies ◽  
Intersection Control

Transportation sustainability is adversely affected by recurring traffic congestions, especially at urban intersections. Frequent vehicle deceleration and acceleration caused by stop-and-go behaviours at intersections due to congestion adversely impacts energy consumption and ambient air quality. Availability of the maturing vehicle technologies such as autonomous vehicles and Vehicle-To-Vehicle (V2V) / Vehicle-To-Infrastructure (V2I) communications provides technical feasibility to develop solutions that can reduce vehicle stops at intersections, hence enhance the sustainability of intersections. This paper presents a next-generation intersection control system for autonomous vehicles, which is named ACUTA. ACUTA employs an enhanced reservation-based control algorithm that controls autonomous vehicles’ passing sequence at an intersection. Particularly, the intersection is divided into n-by-n tiles. An intersection controller reserves certain time-space for each vehicle, and assures no conflict exists between reservations. The algorithm was modelled in microscopic traffic simulation platform VISSIM. ACUTA algorithm modelling as well as enhancement strategies to minimize vehicle intersection stops and eventually emission and energy consumption were discussed in the paper. Sustainability benefits offered by this next-generation intersection were evaluated and compared with traditional intersection control strategies. The evaluation reveals that multi-tile ACUTA reduces carbon monoxide (CO) and Particulate Matter (PM) 2.5 emissions by about 5% under low to moderate volume conditions and by about 3% under high volume condition. Meanwhile, energy consumption is reduced by about 4% under low to moderate volume conditions and by about 12% under high volume condition. Compared with four-way stop control, single-tile ACUTA reduces CO and PM 2.5 emissions as well as energy consumption by about 15% under any prevailing volume conditions. These findings validated the sustainability benefits of employing next-generation vehicle technologies in intersection traffic control. In addition, extending the ACUTA to corridor level was explored in the paper.

scholarly journals Platoon Signal Priority in Connected-Autonomous Vehicle Environments: Algorithm Development and Testing

2019 ◽  
Vol 65 (4) ◽  
pp. 1-9
Author(s):  
Milan Zlatkovic ◽  
Andalib Shams
Keyword(s):  
Traffic Congestion ◽  
Autonomous Vehicles ◽  
Penetration Rate ◽  
Autonomous Vehicle ◽  
Transportation Systems ◽  
Vehicle Technologies ◽  
Measures Of Effectiveness ◽  
Urban Corridor ◽  
Intersection Control ◽  
Day By Day

As traffic congestion increases day by day, it becomes necessary to improve the existing roadway facilities to maintain satisfactory operational and safety performances. New vehicle technologies, such as Connected and Autonomous Vehicles (CAV) have a potential to significantly improve transportation systems. Using the advantages of CAVs, this study developed signalized intersection control strategy algorithm that optimizes the operations of CAVs and allows signal priority for connected platoons. The algorithm was tested in VISSIM microsimulation using a real-world urban corridor. The tested scenarios include a 2040 Do-Nothing scenario, and CAV alternatives with 25%, 50%, 75% and 100% CAV penetration rate. The results show a significant reduction in intersection delays (26% - 38%) and travel times (6% - 20%), depending on the penetration rate, as well as significant improvements on the network-wide level. CAV penetration rates of 50% or more have a potential to significantly improve all operational measures of effectiveness.

scholarly journals An Open-Source Scale Model Platform for Teaching Autonomous Vehicle Technologies

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3850
Author(s):  
Bastien Vincke ◽  
Sergio Rodriguez Rodriguez Florez ◽  
Pascal Aubert
Keyword(s):  
Open Source ◽  
Autonomous Vehicles ◽  
Autonomous Vehicle ◽  
Constrained Systems ◽  
Scale Model ◽  
Technical Students ◽  
Vehicle Technologies ◽  
Model Platform ◽  
High Level ◽  
Time And Energy

Emerging technologies in the context of Autonomous Vehicles (AV) have drastically evolved the industry’s qualification requirements. AVs incorporate complex perception and control systems. Teaching the associated skills that are necessary for the analysis of such systems becomes a very difficult process and existing solutions do not facilitate learning. In this study, our efforts are devoted to proposingan open-source scale model vehicle platform that is designed for teaching the fundamental concepts of autonomous vehicles technologies that are adapted to undergraduate and technical students. The proposed platform is as realistic as possible in order to present and address all of the fundamental concepts that are associated with AV. It includes all on-board components of a stand-alone system, including low and high level functions. Such functionalities are detailed and a proof of concept prototype is presented. A set of experiments is carried out, and the results obtained using this prototype validate the usability of the model for the analysis of time- and energy-constrained systems, as well as distributed embedded perception systems.

scholarly journals Air pollution and out-of-hospital cardiac arrest risk

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
L Moderato ◽  
D Lazzeroni ◽  
A Biagi ◽  
T Spezzano ◽  
B Matrone ◽  
...  
Keyword(s):  
Air Pollution ◽  
Cardiac Arrest ◽  
Ambient Air ◽  
Ambient Air Pollution ◽  
External Temperature ◽  
Pm 2.5 ◽  
Pm10 And Pm2.5 ◽  
Short Term Exposure ◽  
The Impact ◽  
Hospital Cardiac Arrest

Abstract Introduction Out-of-hospital cardiac arrest (OHCA) is a leading cause of death worldwide; it accounts for up to 50% of all cardiovascular deaths.It is well established that ambient air pollution triggers fatal and non-fatal cardiovascular events. However, the impact of air pollution on OHCA is still controversial. The objective of this study was to investigate the impact of short-term exposure to outdoor air pollutants on the incidence of OHCA in the urban area of Piacenza, Italy, one of the most polluted area in Europe. Methods From 01/01/2010 to 31/12/2017 day-by-day PM10 and PM2.5 levels, as well as climatic data, were extracted from Environmental Protection Agency (ARPA) local monitoring stations. OHCA were extracted from the prospective registry of Community-based automated external defibrillator Cardiac arrest “Progetto Vita”. OHCA data were included: audio recordings, event information and ECG tracings. Logistic regression analysis was used to estimate the association between the risk of OHC, expressed as odds ratios (OR), associated with the PM10 and PM2.5 levels. Results Mean PM10 levels were 33±29 μg/m3 and the safety threshold (50 μg/m3) recommended by both WHO and Italian legislation has been exceeded for 535 days (17.5%). Mean PM 5 levels were 33±29 μg/m3. During the follow-up period, 880 OHCA were recorded on 750 days; the remaining 2174 days without OHCA were used as control days. Mean age of OHCA patients was 76±15 years; male gender was prevalent (55% male vs 45% female; <0.001). Concentration of PM10 and PM 2.5 were significantly higher on days with the occurrence of OHCA (PM10 levels: 37.7±22 μg/m3 vs 32.7±19 μg/m3; p<0.001; PM 2.5 levels: 26±16 vs 22±15 p<0.001). Risk of OHCA was significantly increased with the progressive increase of PM10 (OR: 1.009, 95% CI 1.004–1.015; p<0.001) and PM2.5 levels (OR 1.012, 95% CI 1.007–1.017; p<0.001). Interestingly, the above mentioned results remain independent even when correct for external temperature or season (PM 2.5 levels: p=0.01 – PM 10 levels: p=0.002), Moreover, dividing PM10 values in quintiles, a 1.9 fold higher risk of cardiac arrest has been showed in the highest quintile (Highest quintile cut-off: <48μg/m3) Conclusions In large cohort of patients from a high pollution area, both PM10 and PM2.5 levels are associated with the risk of Out-of-hospital cardiac arrest. PM10 and PM2.5 levels and risk of OHCA Funding Acknowledgement Type of funding source: None

scholarly journals Millimeter Wave Spatial Channel Characterization for Vehicular Communications

Proceedings ◽  
2019 ◽  
Vol 42 (1) ◽  
pp. 64 ◽  
Author(s):  
Fidel Rodríguez-Corbo ◽  
Leyre Azpilicueta ◽  
Mikel Celaya-Echarri ◽  
Peio López-Iturri ◽  
Imanol Picallo ◽  
...  
Keyword(s):  
Millimeter Wave ◽  
Autonomous Vehicles ◽  
Communication Systems ◽  
Vehicular Networks ◽  
Small Scale ◽  
Vehicular Communications ◽  
Next Generation ◽  
Vehicular Communication ◽  
High Definition ◽  
High Data

With the growing demand of vehicle-mounted sensors over the last years, the amount of critical data communications has increased significantly. Developing applications such as autonomous vehicles, drones or real-time high-definition entertainment requires high data-rates in the order of multiple Gbps. In the next generation of vehicle-to-everything (V2X) networks, a wider bandwidth will be needed, as well as more precise localization capabilities and lower transmission latencies than current vehicular communication systems due to safety application requirements; 5G millimeter wave (mmWave) technology is envisioned to be the key factor in the development of this next generation of vehicular communications. However, the implementation of mmWave links arises with difficulties due to blocking effects between mmWave transceivers, as well as different channel impairments for these high frequency bands. In this work, the mmWave channel propagation characterization for V2X communications has been performed by means of a deterministic in-house 3D ray launching simulation technique. A complex heterogeneous urban scenario has been modeled to analyze the different propagation phenomena of multiple mmWave V2X links. Results for large and small-scale propagation effects are obtained for line-of-sight (LOS) and non-LOS (NLOS) trajectories, enabling inter-data vehicular comparison. These analyzed results and the proposed methodology can aid in an adequate design and implementation of next generation vehicular networks.

scholarly journals Regional Scale Impact of the COVID-19 Lockdown on Air Quality: Gaseous Pollutants in the Po Valley, Northern Italy

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 264 ◽  
Author(s):  
Giovanni Lonati ◽  
Federico Riva
Keyword(s):  
Air Quality ◽  
Urban Areas ◽  
Regional Scale ◽  
High Volume ◽  
Ambient Air ◽  
Northern Italy ◽  
Traffic Emissions ◽  
Gaseous Pollutants ◽  
Po Valley ◽  
Concentration Levels

The impact of the reduced atmospheric emissions due to the COVID-19 lockdown on ambient air quality in the Po Valley of Northern Italy was assessed for gaseous pollutants (NO2, benzene, ammonia) based on data collected at the monitoring stations distributed all over the area. Concentration data for each month of the first semester of 2020 were compared with those of the previous six years, on monthly, daily, and hourly bases, so that pre, during, and post-lockdown conditions of air quality could be separately analyzed. The results show that, as in many other areas worldwide, the Po Valley experienced better air quality during 2020 spring months for NO2 and benzene. In agreement with the reductions of nitrogen oxides and benzene emissions from road traffic, estimated to be −35% compared to the regional average, the monthly mean concentration levels for 2020 showed reductions in the −40% to −35% range compared with the previous years, but with higher reductions, close to −50%, at high-volume-traffic sites in urban areas. Conversely, NH3 ambient concentration levels, almost entirely due the emissions of the agricultural sector, did not show any relevant change, even at high-volume-traffic sites in urban areas. These results point out the important role of traffic emissions in NO2 and benzene ambient levels in the Po Valley, and confirm that this region is a rather homogeneous air basin with urban area hot-spots, the contributions of which add up to a relatively high regional background concentration level. Additionally, the relatively slow response of the air quality levels to the sudden decrease of the emissions due to the lockdown shows that this region is characterized by a weak exchange of the air masses that favors both the build-up of atmospheric pollutants and the development of secondary formation processes. Thus, air quality control strategies should aim for structural interventions intended to reduce traffic emissions at the regional scale and not only in the largest urban areas.

Pollution Level and Distribution of PCDD/PCDF Congeners between Gas Phase and Particulate Phase in early Spring Air of Dalian, China

2011 ◽  
Vol 71-78 ◽  
pp. 2679-2682
Author(s):  
Xiu Hua Zhu ◽  
Song Tao Qin ◽  
Qian Xu ◽  
Yu Wen Ni ◽  
Ji Ping Chen ◽  
...  
Keyword(s):  
Gas Phase ◽  
Gaseous Phase ◽  
High Volume ◽  
Ambient Air ◽  
Early Spring ◽  
Pollution Level ◽  
Particulate Phase ◽  
Spring Season ◽  
International Standard

Ambient air of Dalian was sampled with active high-volume air samplers in early spring time. The concentrations and the congeners between gas phase and particulate phase of polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs) in the air were measured. Samples analysis results showed that the concentration of PCDD/Fs in particulate phase was higher than that in gas phase. The ratio of PCDD to PCDF in gaseous phase and particulate phase was lower than 0.4. The main sources of atmospheric PCDD/Fs in Dalian early spring season were coal-related source. The total I-TEQ in gaseous phase and particulate phase was 30.3 and 143.6 fg m-3, respectively. The I-TEQ of Dalian early spring atmosphere was lower than international standard, the atmospheric quality in Dalian was better.

scholarly journals Polyfluoroalkyl compounds in the Canadian Arctic atmosphere

2011 ◽  
Vol 8 (4) ◽  
pp. 399 ◽  
Author(s):  
Lutz Ahrens ◽  
Mahiba Shoeib ◽  
Sabino Del Vento ◽  
Garry Codling ◽  
Crispin Halsall
Keyword(s):  
Gas Phase ◽  
Environmental Concern ◽  
Canadian Arctic ◽  
High Volume ◽  
Ambient Air ◽  
Coast Guard ◽  
The Arctic ◽  
Particle Phase ◽  
Method Performance ◽  
Arctic Atmosphere

Environmental contextPerfluoroalkyl compounds are of rising environmental concern because of their ubiquitous distribution in remote regions like the Arctic. The present study quantifies these contaminants in the gas and particle phases of the Canadian Arctic atmosphere. The results demonstrate the important role played by gas–particle partitioning in the transport and fate of perfluoroalkyl compounds in the atmosphere. AbstractPolyfluoroalkyl compounds (PFCs) were determined in high-volume air samples during a ship cruise onboard the Canadian Coast Guard Ship Amundsen crossing the Labrador Sea, Hudson Bay and the Beaufort Sea of the Canadian Arctic. Five PFC classes (i.e. perfluoroalkyl carboxylates (PFCAs), polyfluoroalkyl sulfonates (PFSAs), fluorotelomer alcohols (FTOHs), fluorinated sulfonamides (FOSAs), and sulfonamidoethanols (FOSEs)) were analysed separately in the gas phase collected on PUF/XAD-2 sandwiches and in the particle phase on glass-fibre filters (GFFs). The method performance of sampling, extraction and instrumental analysis were compared between two research groups. The FTOHs were the dominant PFCs in the gas phase (20–138 pg m–3), followed by the FOSEs (0.4–23 pg m–3) and FOSAs (0.5–4.7 pg m–3). The PFCAs could only be quantified in the particle phase with low levels (<0.04–0.18 pg m–3). In the particle phase, the dominant PFC class was the FOSEs (0.3–8.6 pg m–3). The particle-associated fraction followed the general trend of: FOSEs (~25 %) > FOSAs (~9 %) > FTOHs (~1 %). Significant positive correlation between ∑FOSA concentrations in the gas phase and ambient air temperature indicate that cold Arctic surfaces, such as the sea-ice snowpack and surface seawater could be influencing FOSAs in the atmosphere.

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