4,283 research outputs found

    Controller Design and Experimental Validation for Connected Vehicle Systems Subject to Digital Effects and Stochastic Packet Drops

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    Vehicle-to-everything (V2X) communication allows vehicles to monitor the nearby traffic environment, including participants that are beyond the line of sight. Equipping conventional vehicles with V2X devices results in connected vehicles (CVs) while incorporating the information provided by V2X devices into the controllers of automated vehicles (AVs) leads to connected automated vehicles (CAVs). CAVs have great potential for improving driving comfort, reducing fuel consumption and advancing active safety for individual vehicles, as well as enhancing traffic efficiency and mobility for human-dominated traffic systems. In this dissertation, we study a class of connected cruise control (CCC) algorithms for longitudinal control of CAVs, where they respond to the motion information of one or multiple connected vehicles ahead. For validation and demonstration purposes, we utilize a scaled connected vehicle testbed consisting of a group of ground robots, which can provide us with insights about the controller design of full-size vehicles. On the one hand, intermittencies in V2X communication combined with the digital implementation of controllers introduce information delays. To ensure the performance of individual CAVs and the overall traffic, a set of methods is proposed for design and analysis of such communication-based controllers. We validate them with the scaled testbed by conducting a series of experiments on two-car predecessor-follower systems, cascaded predecessor-follower systems, and more complex connected vehicle systems. It is demonstrated that CAVs utilizing information about multiple preceding vehicles in the CCC algorithm can improve the system performance even for low penetration levels. This can be beneficial at the early stage of vehicle automation when human-driven vehicles still dominate the traffic system. On the other hand, we study the delay variations caused by stochastic packet drops in V2X communication and derive the stochastic processes describing the dynamics for the predecessor-follower systems. The dynamics of the mean, second moment and covariance are utilized to obtain stability conditions. Then the results of the two-car predecessor-follower system with stochastic delay variations are extended to an open chain as well as to a closed ring of cascaded predecessor-followers where stochastic packet drops lead to heterogeneity among different V2X devices. It is shown that the proposed analytical methods allow CCC design for CAVs that can achieve stability and stochastic disturbance attenuation in the presence of stochastic packet drops in complex connected vehicle systems.PHDMechanical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/145874/1/wubing_1.pd

    Proceedings of the Salford Postgraduate Annual Research Conference (SPARC) 2011

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    These proceedings bring together a selection of papers from the 2011 Salford Postgraduate Annual Research Conference(SPARC). It includes papers from PhD students in the arts and social sciences, business, computing, science and engineering, education, environment, built environment and health sciences. Contributions from Salford researchers are published here alongside papers from students at the Universities of Anglia Ruskin, Birmingham City, Chester,De Montfort, Exeter, Leeds, Liverpool, Liverpool John Moores and Manchester

    Understanding interactions between autonomous vehicles and other road users: A literature review

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    This review draws on literature relating to the interactions of vehicles with other vehicles, interactions between vehicles and infrastructure, and interactions between autonomous vehicles and cyclists and autonomous vehicles and pedestrians. The available literature relating to autonomous vehicles interactions is currently limited and hence the review has considered issues which will be relevant to autonomous vehicles from reading and evaluating a broader but still relevant literature.The project is concerned primarily with autonomous vehicles within the urban environment and hence the greatest consideration has been given to interactions on typical urban roads, with specific consideration also being given to shared space. The central questions in relation to autonomous vehicles and other road users revolve around gap acceptance, overtaking behaviour, behaviour at road narrowings, the ability to detect and avoid cyclists taking paths through a junction which conflict with the autonomous vehicle’s path, and the ability of autonomous vehicles to sense and respond to human gestures. A long list of potential research questions has been developed, many of which are not realistically answerable by the Venturer project. However, the important research questions which might potentially be answered by the current project are offered as the basis for the more detailed consideration of the conduct of the interaction trial

    Before and After the Wheel: Precolonial and Colonial States and Transportation in Mainland Southeast Asia and West Africa

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    The present article seeks to demonstrate the important influence pre-colonial roads and overland transportation had on the emergence of modern transportation systems in modern Africa and Southeast Asia. To do so, it examines the pre-colonial and colonial transition and the relationship of the court and colonial administration respectively to changing transportation technologies and geographies of movement. It argues that certain pre-colonial attitudes regarding movement, transportation, and traffic had an important influence on emerging colonial transportation networks. The article examines central political attention to mobility, transport, and traffic (or not) and attention to the thinking about the act of governing them (or not) to reveal continuities attitudes that are invisible when looked at through the lens of technological and regime change alone. It is also suggested that these continuities provide one of a number of the inside stories of state formation and change from the pre-colonial to colonial eras in examples drawn from West Africa and Southeast Asia (including Sri Lanka) for the purpose of this paper. Ultimately, these continuities may help to partially explain other aspects of the directions these two examples took after independence

    AVENUE21. Connected and Automated Driving: Prospects for Urban Europe

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    This open access publication examines the impact of connected and automated vehicles on the European city and the conditions that can enable this technology to make a positive contribution to urban development. The authors argue for two theses that have thus far received little attention in scientific discourse: as connected and automated vehicles will not be ready for use in all parts of the city for a long time, previously assumed effects – from traffic safety to traffic performance as well as spatial effects – will need to be re-evaluated. To ensure this technology has a positive impact on the mobility of the future, transport and settlement policy regulations must be adapted and further developed. Established territorial, institutional and organizational boundaries must be investigated and challenged quickly. Despite – or, indeed, because of – the many uncertainties, we find ourselves at the beginning of a new design phase, not only in terms of technology development, but also regarding politics, urban planning, administration and civil society

    Advanced Control and Estimation Concepts, and New Hardware Topologies for Future Mobility

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    According to the National Research Council, the use of embedded systems throughout society could well overtake previous milestones in the information revolution. Mechatronics is the synergistic combination of electronic, mechanical engineering, controls, software and systems engineering in the design of processes and products. Mechatronic systems put “intelligence” into physical systems. Embedded sensors/actuators/processors are integral parts of mechatronic systems. The implementation of mechatronic systems is consistently on the rise. However, manufacturers are working hard to reduce the implementation cost of these systems while trying avoid compromising product quality. One way of addressing these conflicting objectives is through new automatic control methods, virtual sensing/estimation, and new innovative hardware topologies

    Workshop sensing a changing world : proceedings workshop November 19-21, 2008

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