Where to Decide? Centralized vs. Distributed Vehicle Assignment for Platoon Formation

Platooning is a promising cooperative driving application for future intelligent transportation systems. In order to assign vehicles to platoons, some algorithm for platoon formation is required. Such vehicle-to-platoon assignments have to be computed on-demand, e.g., when vehicles join or leave the freeways. In order to get best results from platooning, individual properties of involved vehicles have to be considered during the assignment computation. In this paper, we explore the computation of vehicle-to-platoon assignments as an optimization problem based on similarity between vehicles. We define the similarity and, vice versa, the deviation among vehicles based on the desired driving speed of vehicles and their position on the road. We create three approaches to solve this assignment problem: centralized solver, centralized greedy, and distributed greedy, using a Mixed Integer Programming solver and greedy heuristics, respectively. Conceptually, the approaches differ in both knowledge about vehicles as well as methodology. We perform a large-scale simulation study using PlaFoSim to compare all approaches. While the distributed greedy approach seems to have disadvantages due to the limited local knowledge, it performs as good as the centralized solver approach across most metrics. Both outperform the centralized greedy approach, which suffers from synchronization and greedy selection effects.Since the centralized solver approach assumes global knowledge and requires a complex Mixed Integer Programming solver to compute vehicle-to-platoon assignments, we consider the distributed greedy approach to have the best performance among all presented approaches

Improved information flow topology for vehicle convoy control

A vehicle convoy is a string of inter-connected vehicles moving together for mutual support, minimizing traffic congestion, facilitating people safety, ensuring string stability and maximizing ride comfort. There exists a trade-off among the convoy's performance indices, which is inherent in any existing vehicle convoy. The use of unrealistic information flow topology (IFT) in vehicle convoy control, generally affects the overall performance of the convoy, due to the undesired changes in dynamic parameters (relative position, speed, acceleration and jerk) experienced by the following vehicle. This thesis proposes an improved information flow topology for vehicle convoy control. The improved topology is of the two-vehicle look-ahead and rear-vehicle control that aimed to cut-off the trade-off with a more robust control structure, which can handle constraints, wider range of control regions and provide acceptable performance simultaneously. The proposed improved topology has been designed in three sections. The first section explores the single vehicle's dynamic equations describing the derived internal and external disturbances modeled together as a unit. In the second section, the vehicle model is then integrated into the control strategy of the improved topology in order to improve the performance of the convoy to two look-ahead and rear. The changes in parameters of the improved convoy topology are compared through simulation with the most widely used conventional convoy topologies of one-vehicle look-ahead and that of the most human-driver like (the two-vehicle look-ahead) convoy topology. The results showed that the proposed convoy control topology has an improved performance with an increase in the intervehicular spacing by 19.45% and 18.20% reduction in acceleration by 20.28% and 15.17% reduction in jerk by 25.09% and 6.25% as against the one-look-ahead and twolook- ahead respectively. Finally, a model predictive control (MPC) system was designed and combined with the improved convoy topology to strictly control the following vehicle. The MPC serves the purpose of handling constraints, providing smoother and satisfactory responses and providing ride comfort with no trade-off in terms of performance or stability. The performance of the proposed MPC based improved convoy topology was then investigated via simulation and the results were compared with the previously improved convoy topology without MPC. The improved convoy topology with MPC provides safer inter-vehicular spacing by 13.86% refined the steady speed to maneuvering speed, provided reduction in acceleration by 32.11% and a huge achievement was recorded in reduction in jerk by 55.12% as against that without MPC. This shows that the MPC based improved convoy control topology gave enough spacing for any uncertain application of brake by the two look-ahead or further acceleration from the rear-vehicle. Similarly, manoeuvering speed was seen to ensure safety ahead and rear, ride comfort was achieved due to the low acceleration and jerk of the following vehicle. The controlling vehicle responded to changes, hence good handling was achieved

Cooperative control of autonomous connected vehicles from a Networked Control perspective: Theory and experimental validation

Formation control of autonomous connected vehicles is one of the typical problems addressed in the general context of networked control systems. By leveraging this paradigm, a platoon composed by multiple connected and automated vehicles is represented as one-dimensional network of dynamical agents, in which each agent only uses its neighboring information to locally control its motion, while it aims to achieve certain global coordination with all other agents. Within this theoretical framework, control algorithms are traditionally designed based on an implicit assumption of unlimited bandwidth and perfect communication environments. However, in practice, wireless communication networks, enabling the cooperative driving applications, introduce unavoidable communication impairments such as transmission delay and packet losses that strongly affect the performances of cooperative driving. Moreover, in addition to this problem, wireless communication networks can suffer different security threats. The challenge in the control field is hence to design cooperative control algorithms that are robust to communication impairments and resilient to cyber attacks. The work aim is to tackle and solve these challenges by proposing different properly designed control strategies. They are validated both in analytical, numerical and experimental ways. Obtained results confirm the effectiveness of the strategies in coping with communication impairments and security vulnerabilities

Technical, economic and energetic competitiveness of rail-road combined transport: evaluation of the effects of possible ITS applications on intermodal terminal.

L'abstract è presente nell'allegato / the abstract is in the attachmen

Techno-economic and socio-economic modelling of energy in road transport to inform climate policy

The release of increasing amounts of anthropogenic greenhouse gas emissions and the corresponding global temperature rise has prompted a growing political consensus on a decarbonised future to prevent any sustained economic or environmental harm. Many countries are using modelling tools to develop strategies and policy measures to deliver timely and effective reductions of harmful greenhouse gas emissions across all energy related sectors. Techno-economic models have a track record in developing low carbon pathways from a technical standpoint, though they have generally failed to adequately account for the underlying socio-economic behaviour which drives consumers in their choices. This thesis highlights and addresses this failing in two parts with a focus on road transport, one of the most difficult sectors to decarbonise. The first part of this thesis reviews the functionality of techno-economic road transportation models and identifies the limitations associated with their operation. The thesis expands upon the International Energy Agency’s global techno-economic simulation transport model, MoMo, with a focus on the freight sector. Next, a national focus is provided, building and applying a simulation techno-economic model of Ireland’s light commercial vehicle stock. This is soft-linked with an optimisation model of the Irish energy system, Irish TIMES. This multi-model methodology is then applied to Ireland’s private car sector, where the limitations of using techno-economic modelling techniques in isolation are identified. The second part of this thesis develops novel socio-economic approaches and integrates these with techno-economic models. A review of socio-economic modelling methods within transport models is performed, identifying the options available for integration with other models. These methods are then tested on the Irish and Danish private car sector, where a consumer choice model is built and integrated with a techno-economic simulation model. Finally, this integration is further coupled with a TIMES optimisation model, focusing on Denmark, which uses a time travel budget to further include behavioural realism into transport focused modelling. The contribution of this thesis is the improvements made to the modelling methods and more robust evidence base for developing sound low-carbon policy measures by integrating technoeconomic and socio-economic frameworks coupled with a combination of optimisation and simulation modelling methods within the road transportation sector

Solving Complex Data-Streaming Problems by Applying Economic-Based Principles to Mobile and Wireless Resource Constraint Networks

The applications that employ mobile networks depend on the continuous input of reliable data collected by sensing devices. A common application is in military systems, where as an example, drones that are sent on a mission can communicate with each other, exchange sensed data, and autonomously make decisions. Although the mobility of nodes enhances the network coverage, connectivity, and scalability, it introduces pressing issues in data reliability compounded by restrictions in sensor energy resources, as well as limitations in available memory, and computational capacity. This dissertation investigates the issues that mobile networks encounter in providing reliable data. Our research goal is to develop a diverse set of novel data handling solutions for mobile sensor systems providing reliable data by considering the dynamic trajectory behavior relationships among nodes, and the constraints inherent to mobile nodes. We study the applicability of economic models, which are simplified versions of real-world situations that let us observe and make predictions about economic behavior, to our domain. First, we develop a data cleaning method by introducing the notion of “beta,” a measure that quantifies the risk associated with trusting the accuracy of the data provided by a node based on trajectory behavior similarity. Next, we study the reconstruction of highly incomplete data streams. Our method determines the level of trust in data accuracy by assigning variable “weights” considering the quality and the origin of data. Thirdly, we design a behavior-based data reduction and trend prediction technique using Japanese candlesticks. This method reduces the dataset to 5% of its original size while preserving the behavioral patterns. Finally, we develop a data cleaning distribution method for energy-harvesting networks. Based on the Leontief Input-Output model, this method increases the data that is run through cleaning and the network uptime

Making Infrastructure Legible

This thesis represents the development and pilot application of a novel methodology for the speculative qualitative assessment (or “prototyping”) of new infrastructural systems. Its core aim and guiding principle is to make infrastructure legible: to reveal and narrate its role in everyday life from a more human perspective than that of the paradigmatic technology-focussed approach. Or, more simply, the project aims to understand how infrastructures develop, how they evolve and entangle over time. The methodology is centred on a novel model of sociotechnical change, known as the infrastructural trialectic. The trialectic makes a unique relational distinction between infrastructural systems and the technologies through which infrastructural functions are accessed, traces vectors of influence between focal actors in the model, and provides a framework for mapping the articulatory institutions which are enrolled in the formation and mutation of infrastructural assemblages. The methodology has two modes of application: the historical mode, and the speculative. In the historical mode, the trialectic model becomes the lens of a situated longue duree analysis which explores the historical dynamics of sociotechnical change in the assemblages underpinning a particular everyday practice. In the speculative mode, the findings from the historical mode are used as the basis for an extrapolative and speculative analysis of a novel technological intervention into the practice previously analysed. Drawing on techniques from strategic foresight and critical design, the prospective technology is “prototyped” against the context of a suite of four divergent near-future scenarios, so as to “stress test” the plausibility of its deployment under difficult circumstances. This thesis presents and applies a novel model of sociotechnical change, and in doing so demonstrates that the shortcomings of paradigmatic models of change might be addressed through such an approach. It further demonstrates a unique hybrid method for the assessment and critique of new technologies and practices alike, which provides a more human perspective upon infrastructure (and indeed upon change itself) than prevailing approaches to assessment

Automated vehicles and future transport inequalities in the UK. Exploring the potential accessibility implications for older people

It is often argued that automated vehicles (AVs) will reduce the unmet accessibility needs of older people. However, these assumptions tend to overlook the potential barriers to AV uptake for older population groups and the fact that AVs may have broader effects on mobility behaviours and transport systems. Although these impacts cannot be predicted with certainty, early engagement with these questions may assure that older people’s accessibility needs are considered in future transport policy. The thesis focuses on two critical research gaps to untangle the future accessibility implications of AVs. First, it explores how transport policymakers perceive and plan to manage the effects of AVs on older people’s accessibility. Second, it investigates older people’s perceptions and acceptance of AVs. The research draws from a content analysis of strategy and planning documents from transport authorities in England and interviews with transport policymakers and experts. Key findings are that while there is an emphasis on the potential of AVs for the UK ageing society, certain barriers to adoption of AVs are often overlooked. Moreover, the potential impacts of AVs on older people’s accessibility as users of other modes (e.g. walking) are not considered. Transport authorities have mostly played a facilitating role in the development of AVs, but have not yet developed plans and policies to ensure that older people will benefit from the transition to AVs. Through interviews with older citizens in Greater Manchester, the research identifies that some older people perceive that AVs would improve their current or future accessibility levels. Nevertheless, several factors may inhibit the ability and willingness of some older population groups to use AVs. Finally, the study explored older people’s acceptance of different automated transport services. Although most interviewees appeared as willing to use at least some of the proposed services, some showed strong reluctance to use AVs

Towards Our Common Digital Future. Flagship Report.

In the report “Towards Our Common Digital Future”, the WBGU makes it clear that sustainability strategies and concepts need to be fundamentally further developed in the age of digitalization. Only if digital change and the Transformation towards Sustainability are synchronized can we succeed in advancing climate and Earth-system protection and in making social progress in human development. Without formative political action, digital change will further accelerate resource and energy consumption, and exacerbate damage to the environment and the climate. It is therefore an urgent political task to create the conditions needed to place digitalization at the service of sustainable development