Cooperative Traffic Control Solution for Vehicle Transition from Autonomous to Manual Mode exploiting Cellular Vehicle-to-Everything (C-V2X) Technology

Nowadays, automated vehicles represent a promising technology to face the stringent requirements for safety and traffic efficiency in the automotive environment. Driving responsibilities will be gradually addressed to the machine, and the role of human pilots will be progressively reduced to passengers. The interaction between passengers and the automated system will create different risks that have not been considered in the past. In particular, the transition between autonomous and manual mode is understood as a risky situation. During the transition, the driver manifests driving irregularities and loss of situation awareness that may endanger himself and other participants on the road. Hence, the vehicle transitioning needs a higher quantity of space around it to be considered safe. However, no effective solution has been developed yet. This thesis aims to design a cooperative traffic control solution that will manage the movements of the group of vehicles to increase the free space around the one transitioning. It will exploit another tool that will play a fundamental role in the future of the automotive industry: connected vehicles technology. C-V2X technology will create a medium for vehicles to exchange information and cooperate. A controller managing the cooperation between vehicles has been developed to help a smooth and safe vehicle repositioning. The controller will be positioned in a centralized computing facility and it will communicate with all the vehicles. The controller defines rules to move vehicles together and enlarge the free space around the vehicle transitioning without collisions. The rules are modeled by a spring-mass-damper system, that can be exploited to control the longitudinal behavior of automated vehicles. In particular, the spring-mass-damper system can manage smooth migration between vehicle dispositions without oscillations. A computer simulation is used to test the performance of the proposed traffic control system. The simulation environment is constituted by three main components: traffic flow, controller and communication network. It has been tested with the software VEINS, which provides interaction between a network simulator (OMNeT++) and a traffic simulator (SUMO). The traffic flow represents the interactions between vehicles. The controller analyzes the data and sends control messages to all vehicles. The communication network will share the data concerning vehicles’ position and speed and control messages. The proposed cooperative vehicle control system demonstrated to reduce the risks of the transition with the smooth motion of vehicles. The controller is able to achieve the safety requirements without reducing the level of comfortability of vehicles’ passengers

Impact of the dropping activity with vehicle age on air pollutant emissions

Road transport is a major source of air pollution especially in cities. Detailed calculations are needed to support road transport emission inventories due to the variance of technologies and operating conditions encountered on the roads. The annual distance driven by cars in relation to their characteristics is an important variable in such calculations. In this work, a large amount of mileage data were collected from second–hand car sellers in Italy and were then analyzed in order to understand the influence of vehicle age on annual mileage driven. The available data enabled the development of dropping functions of annual mileage with vehicle age. It was found that the average mileage of 10 year old cars is only approximately 40% of the mileage driven on year one. This drops to approximately only 10% for 20–year old cars. The findings are of paramount importance in environmental calculations as road transport NOX and PM emissions drop by more than 20% when the corrected functions are used compared to using a constant mileage. Not introducing such a correction may result to an approximately 8% higher nation–wide NOX emissions with negative implications towards meeting the national emission ceilings. In terms of policy implications, the dropping activity with age results to a decrease in the importance of accelerated scrappage schemes and of environmental zones in air quality

Impact of the dropping activity with vehicle age on air pollutant emissions

AbstractRoad transport is a major source of air pollution especially in cities. Detailed calculations are needed to support road transport emission inventories due to the variance of technologies and operating conditions encountered on the roads. The annual distance driven by cars in relation to their characteristics is an important variable in such calculations. In this work, a large amount of mileage data were collected from second–hand car sellers in Italy and were then analyzed in order to understand the influence of vehicle age on annual mileage driven. The available data enabled the development of dropping functions of annual mileage with vehicle age. It was found that the average mileage of 10 year old cars is only approximately 40% of the mileage driven on year one. This drops to approximately only 10% for 20–year old cars. The findings are of paramount importance in environmental calculations as road transport NOX and PM emissions drop by more than 20% when the corrected functions are used compared to using a constant mileage. Not introducing such a correction may result to an approximately 8% higher nation–wide NOX emissions with negative implications towards meeting the national emission ceilings. In terms of policy implications, the dropping activity with age results to a decrease in the importance of accelerated scrappage schemes and of environmental zones in air quality

Domestic heating from forest logging residues: environmental risks and benefits

The European Union (EU) relies largely on bioenergy to achieve its climate and energy targets for 2020 and beyond. Special focus is placed on utilization of biomass residues, which are considered to cause low environmental impacts. We used the dataset from the latest European Commission document on the sustainability of solid and gaseous biomass (SWD2014 259), complementing those results by: i) designing three pathways for domestic-heat production using forest logging residues, with different combustion technologies; ii) expanding the analysis to include forest carbon stock development with and without bioenergy; iii) using absolute climate metrics to assess the surface temperature response by the end of the century to a bioenergy and a reference fossil system; iv) including multiple climate forcers (well-mixed GHG, near term climate forcers and surface albedo change); iv) quantifying life cycle impacts on acidification, particulate matter emissions and photochemical ozone formation; v) reviewing potential risks for forest ecosystem degradation due to increased removal of residues. Supply-chain GHG savings of the three pathways analysed ranged between 80% and 96% compared to a natural gas system, above the 70% threshold suggested by the EU. However, the climate impact of bioenergy should be assessed by considering also the non-bioenergy uses of the biomass and by including all climate forcers. We calculate the Surface Temperature Response to bioenergy and fossil systems by means of Absolute Global surface Temperature Potential (AGTP) metric. Domestic heating from logging residues is generally beneficial to mitigate the surface temperature increase by 2100 compared to the use of natural gas and other fossil sources. As long as residues with a decay rate in the forest higher than 2.7%*yr1 are considered as feedstock, investing now in the mobilization of residues for heat production can reduce the temperature increase by 2100 compared to all the fossil sources analysed, both in case of bioenergy as a systemic change or in case of bioenergy as a transitory option. Furthermore, several environmental risks are associated with the removal and use of forest logging residues for bioenergy. These issues concern mostly local air pollution, biodiversity loss and, mainly for stumps removal, physical damage to forest soils. Forest logging residues are not free of environmental risks. Actions promoting their use should consider: (i) that climate change mitigation depends mainly on the decay rate of biomass under natural decomposition and time and rate of technology deployment, (ii) whether management guidelines aimed at protecting long-term forest productivity are in place and (iii) whether proper actions for the management of adverse effects on local air pollution are in place

Influence of climate change on the frequency of daytime temperature inversions and stagnation events in the Po Valley: historical trend and future projections

This work analyzes the frequency of days characterized by daytime temperature inversion and air stagnation events in the Po valley area. The analysis is focused on both historical series and future projections under climate change. Historical sounding data from two different Italian stations are used as well as future projections data, provided by CMCC-CCLM 4-8-19 regional climate model (MED-CORDEX initiative). A new method to detect layers of temperature inversion is also presented. The developed method computes the occurrence of a temperature inversion layer for a given day at 12 UTC without a detailed knowledge of temperature vertical profile. This method was validated using sounding data and applied to the model projections, under two different emissions scenarios (RCP4.5 and RCP8.5). Under RCP4.5 intermediate emissions scenario, the occurrence of temperature inversions is projected to increase by 12 days/year (around + 10%) in the last decade of 21st century compared to 1986–2005 average. However, the increase in temperature inversions seems to be especially concentrated in the warm period. Under RCP8.5 extreme scenario, temperature inversions are still projected to increase, though to a lesser extent compared to RCP4.5 scenario (+ 6 days/year in the last decade of 21st century). A similar trend was found also for air stagnation events, which take into account the variation of precipitation pattern and wind strength. The expected increases are equal to + 13 days/year and + 11 days/year in the last decade of 21st century compared to 1986–2005 average, under RCP4.5 and RCP8.5 scenarios respectively

Climate change impacts of power generation from residual biomass

The European Union relies largely on bioenergy to achieve its climate and energy targets for 2020 and beyond. We assess, using Attributional Life Cycle Assessment (A-LCA), the climate change mitigation potential of three bioenergy power plants fuelled by residual biomass compared to a fossil system based on the European power generation mix. We study forest residues, cereal straws and cattle slurry. Our A-LCA methodology includes: i) supply chains and biogenic-CO2 flows; ii) explicit treatment of time of emissions; iii) instantaneous and time-integrated climate metrics. Power generation from cereal straws and cattle slurry can provide significant global warming mitigation by 2100 compared to current European electricity mix in all of the conditions considered. The mitigation potential of forest residues depends on the decay rate considered. Power generation from forest logging residues is an effective mitigation solution compared to the current EU mix only in conditions of decay rates above 5.2% a−1. Even with faster-decomposing feedstocks, bioenergy temporarily causes a STR(i) and STR(c) higher than the fossil system. The mitigation potential of bioenergy technologies is overestimated when biogenic-CO2 flows are excluded. Results based solely on supply-chain emissions can only be interpreted as an estimation of the long-term (>100 years) mitigation potential of bioenergy systems interrupted at the end of the lifetime of the plant and whose carbon stock is allowed to accumulate back. Strategies for bioenergy deployment should take into account possible increases in global warming rate and possible temporary increases in temperature anomaly as well as of cumulative radiative forcing

Le emissioni in atmosfera dalle combustioni in Lombardia

Il lavoro presenta le stime delle emissioni in atmosfera di polveri fini, precursori di polveri fini e gas serra in Lombardia provenienti dalle attività di combustione di combustibili e carburanti, come stimate dall’inventario regionale INEMAR per l’anno 2003. I dati dei consumi elaborati nell’inventario derivano da informazioni raccolte sia mediante questionari relativi alle principali sorgenti puntuali della regione, sia consultando le diverse fonti statistiche. Le emissioni in atmosfera sono stimate sia attraverso dati derivanti da misure effettuate presso gli impianti che tramite fattori di emissione proposti in letteratura e utilizzati in ambito EMEP-Corinair e IPCC (Intergovernmental Panel on Climate Change). La combustione nel settore del trasporto stradale risulta essere la principale sorgente per numerosi inquinanti, fra cui PM10, NOx, SO2 e CO. L’olio combustibile utilizzato per la produzione di energia è la maggiore fonte di SO2 (56% delle emissioni totali regionali), mentre il gasolio per autotrazione fornisce il principale contributo alle emissioni di NOx (44% del totale). Per le emissioni di polveri (sia PM10 che PM2,5), oltre ai determinanti contributi della combustione del gasolio per autotrazione e della legna in ambito domestico, sono rilevanti anche i processi di usura nel traffico stradale (pneumatici, freni, abrasione dell’asfalto) e le attività relative al settore agro-zootecnico. La benzina è la principale fonte di CO (50%), mentre il metano costituisce una sorgente di grande importanza (45%) per la CO2 e di interesse anche per gli ossidi di azoto (21% del totale regionale). Il lavoro fornisce altresì una valutazione dei fattori di emissione medi dalle attività di combustione in Lombardia a diverse scale di dettaglio

Milano Citt\ue0 Metropolitana Resiliente : un percorso operativo a supporto della redazione del futuro Piano Territoriale Metropolitano

Il contributo si pone l\u2019obiettivo di presentare il percorso di ricerca svolto per supportare la redazione di un piano clima per la Citt\ue0 Metropolitana di Milano. Il lavoro svolto ha avuto l\u2019obiettivo di allineare il contesto locale della CMM al dibattito internazionale e ai nuovi temi della pianificazione climatica integrata alla pianificazione territoriale e spaziale e perseguire i target di riduzione delle emissioni di gas serra e di risposta all\u2019adattamento gi\ue0 stabiliti a livello internazionale. Nello specifico, a partire dall\u2019esperienza pianificatoria della CMM, dal capitale tecnico gi\ue0 attivo sui temi proposti, e a seguito di una ricognizione approfondita dello stato dell\u2019arte in tema di pianificazione per l\u2019energia e il clima a livello locale, lo studio si \ue8 occupato di: (1) portare conoscenza e trasferire i temi del cambiamento climatico all'interno delle pratiche pianificatorie locali, rileggendo strumenti e piani nell\u2019ottica della resilienza territoriale; (2) comunicare e disseminare le sfide dei cambiamenti climatici alle popolazioni locali, comprese le attivit\ue0 formative rivolte ai tecnici dell\u2019amministrazione pubblica; (3) affrontare le sfide spaziali e climatiche in maniera integrata con obiettivi di efficacia. Il lavoro pone in particolare l\u2019accento sull\u2019importanza della dimensione spaziale e morfologica dei diversi contesti urbanizzati nell\u2019affrontare strategie e soluzioni di adattamento, aspetto spesso trascurato dalla pianificazione climatica. La costruzione di mappe di vulnerabilit\ue0 alla micro-scala locale consente, infatti, di proporre soluzioni meta-progettuali specifiche e azioni su misura per i diversi contesti, aumentando quindi l\u2019efficacia degli interventi