Model Predictive Control Based Trajectory Generation for Autonomous Vehicles - An Architectural Approach

Research in the field of automated driving has created promising results in the last years. Some research groups have shown perception systems which are able to capture even complicated urban scenarios in great detail. Yet, what is often missing are general-purpose path- or trajectory planners which are not designed for a specific purpose. In this paper we look at path- and trajectory planning from an architectural point of view and show how model predictive frameworks can contribute to generalized path- and trajectory generation approaches for generating safe trajectories even in cases of system failures.Comment: Presented at IEEE Intelligent Vehicles Symposium 2017, Los Angeles, CA, US

Modelling drivers' car parking behaviour using data from a travel choice simulator

This paper reports on models developed from data collected using the PARKIT parking choice simulator. PARKIT provided an experimental environment in which drivers’ choice of car parks, and of the routes chosen to reach them, could be observed and the influence of different levels of parking-stock knowledge (derived from experience or from information provided via roadside message signs) monitored. Separate models were estimated for the drivers’ initial choice of car park and for their revision of that choice as their journey progresses and they learn about actual conditions. The importance of price, walking time and driving distance is confirmed but the addition of variables describing the drivers’ choices on previous days, their expectations and their immediately preceding route-choice, greatly improved the models’ explanatory power. It is noted that variables such as these are not generally considered because they are rarely available to the modeller. Different discrete choice model structures were found to be appropriate for different decisions. Route choice was represented as an exit-choice model (whereby each journey is treated as a sequence of decisions – one at each intersection encountered). The paper discusses the incorporation of these choice models into a network assignment model and concludes that much of the power of the choice models is lost if the network model is not able to support use of information about travellers’ socio-economic characteristics and knowledge of the network and about the detailed network topology

Stakeholder engagement in sustainable housing refurbishment in the UK

The UK government is committed to effectively implement a viable sustainable agenda in the social housing sector. To this end housing associations and local authorities are being encouraged to improve the environmental performance of their new and existing homes. Whilst much attention has been focused on new housing (e.g. the Code for Sustainable Homes) little effort has been focussed on improving the 3.9 (approx) million homes maintained and managed by the public sector (in England), which, given the low rate of new build and demolition (<1% in England), will represent approximately 70% of the public housing stock in 2050. Thus, if UK is to achieve sustainable public housing the major effort will have to focus on the existing stock. However, interpreting the sustainability agenda for an existing housing portfolio is not a straight foreword activity. In addition to finding a ‘technical’ solution, landlords also haveto address the socio-economic issues that balance quality of expectations of tenants with the economic realities of funding social housing refurbishment. This paper will report the findings of a qualitative study (participatory approach) that examined the processes by which a large public landlord sought to develop a long-term sustainable housing strategy. Through a series of individual meetings and group workshops the research team identified: committed leadership; attitudes towards technology; social awareness; and collective understanding of the sustainability agenda as key issues that the organisation needed to address in developing a robust and defendable refurbishment strategy. The paper concludes that the challenges faced by the landlord in improving the sustainability of their existing stock are not primarily technical, but socio-economic. Further, while the economic challenges: initial capital cost; lack of funding; and pay-back periods can be overcome, if the political will exists, by fiscal measures; the social challenges: health & wellbeing; poverty; security; space needs; behaviour change; education; and trust; are much more complex in nature and will require a coordinated approach from all the stakeholders involved in the wider community if they are to be effectively addressed. The key challenge to public housing landlords is to develop mechanisms that can identify and interpret the complex nature of the social sustainability agenda in a way that reflects local aspirations (although the authors believe the factors will exist in all social housing communities, their relative importance is likely to vary between communities) whilst addressing Government agendas

Mission analysis of Hevelius-lunar microsatellite mission

This paper describes the mission analysis and design of the 'Hevelius - Lunar Microsatellite Mission'. The main goal of the overall mission is to place a net-lander on the far side of the Moon to perform some scientific experiments. Two different satellites have been designed to achieve this objective: a microsatellite orbiter to support the net-lander and a carrier spacecraft to transport the net-lander. An L2 Halo orbit has been selected for the orbiter in order to have a constant communication link between the landers and the Earth. The invariant manifolds of the Earth-Moon system have been used to design a low cost transfer trajectory to the L2 Halo orbit. Prior to the beginning of landing operations the carrier is parked into a frozen orbit after a WSB transfer. Finally the descent and landing phases have been designed in order to accomplish the final goals. The whole mission analysis and design process has been driven by the need for a low cost and low risk mission

Analysing parking search (‘cruising’) time using generalised multilevel structural equation modelling

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the URI link.The aim of this paper is to identify factors influencing parking search (cruising) time. A revealed-preference on-street parking survey was undertaken with individual drivers in four UK cities to investigate the influence of personal, trip, socio-economic, physical, time49 related, and price-related variables on parking search. In order to address the potential endogeneity problems between the factors (e.g. parking fee and parking search time) and hierarchical issues in the survey data, a generalised multilevel structural equation model was applied. It was revealed that cruising time could be reduced by seeking drivers to pay for parking as a way of improving social welfare