| 1. |
- Voronov, Alexey, et al.
(författare)
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Radar reflecting pavement markers for vehicle automation
- 2016
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Konferensbidrag (refereegranskat)abstract
- Dependable and fail-safe control of autonomous vehicles requires multiple independent sensors for lane detection and positioning. From analysis of modern sensing technologies, we conclude that radars are underutilized for positioning, and that they might be an enabling technology for achieving safety requirements posed by the standard ISO 26262. To fully utilize the radar potential, we have conducted a pre-study of equipping infrastructure with radar reflectors. We estimate that such reflectors should be installed in the lane markings, about 20-25 meters apart and with some kind of identification. We propose to design and evaluate a combi-reflector based on the traditional cat’s eye design, which will be detectable both by human drivers, radars and lidars. Furthermore, the combi-reflector can be equipped with a magnet for in-vehicle electromagnetic field sensor. From the redundancy evaluation performed, we conclude that the proposed solution increases the level of redundancy significantly. Therefore, the proposed solution could be an enabler for autonomous driving.
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| 2. |
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| 3. |
- Engdahl, Henrik, et al.
(författare)
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Statistical Data for Free-floating Car Sharing versusPublic Transport
- 2017
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Konferensbidrag (refereegranskat)abstract
- Free-floating car sharing is a form of car rental used by people for short periods of time where the cars canbe picked up and returned anywhere within a given area. In this paper, we have collected free-floating carsharing data, for electric as well as fossil fueled cars, and data for alternative trips using cycling, walking andpublic transport for the cities of Amsterdam, Berlin, Denver, Madrid, San Diego and Seattle. From this data,free-floating car sharing seems to be a compliment to other type of transports, including public transports,bicycling and walking, and not a competitor.
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| 4. |
- Englund, Cristofer, et al.
(författare)
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Method for prediction of utilization rate of electric vehicle free-floating car sharing services using data mining
- 2018
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Ingår i: 31st International Electric Vehicle Symposium and Exhibition, EVS 2018 and International Electric Vehicle Technology Conference 2018, EVTeC 2018.
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Konferensbidrag (refereegranskat)abstract
- Free-floating car sharing is a form of car rental used by people for short periods of time where the cars can be picked up and returned anywhere within a given area. In this paper, we have collected free-floating car sharing data, for electric as well as fossil fueled cars, and data regarding e.g. size of the city, number of cars in the service, etc. The utilization rates of the free-floating car sharing services vary much between the cities, greatly influencing the success of the services. This paper presents the most important factors influencing the utilization rate, and also a methodology to predict the utilization rate for new cities, using data mining based on Random Forests.
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| 5. |
- Habibi, Shiva, 1978, et al.
(författare)
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Comparison of free-floating car-sharing services in cities
- 2017
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Ingår i: ECEEE Summer Study, 29 May - 3 June, 2017. - 2001-7960. - 9789198387810 ; 2017
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Konferensbidrag (refereegranskat)abstract
- In recent years, free-floating car sharing services (FFCS) have been offered by many organizations as a more flexible option compared to traditional car sharing. FFCS allows users to pick up and return cars anywhere within a specified area of a city. FFCS can provide a high degree of utilization of vehicles and less usage of infrastructure in the form of parking lots and roads and thus has the potential to increase the efficiency of the transport sector. However, there is also a concern that these compete with other efficient modes of transport such as cycling and public transport. The aim of this paper is to better understand how, when and where the vehicles are utilized through logged data of the vehicles’ movements. We have access to data collected on FFCS services in 22 cities in Europe and North America which allows us to compare the usage pattern in different cities and examine whether or not there are similar trends. In this paper, we use the collected data to compare the different cities based on utilization rate, length of trip and time of day that the trip is made. We find that the vehicle utilization rates differ between cities with Madrid and Hamburg having some of the highest utilization levels for the FFCS vehicles. The results form a first step of a better understanding on how these services are being used and can provide valuable input to local policy makers as well as future studies such as simulation models.
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| 6. |
- Habibi, Shiva, et al.
(författare)
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Success and usage pattern of free-floating car sharing services in cities
- 2018
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Ingår i: Transportation Research Board (TRB) Meeting 2018.
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Konferensbidrag (refereegranskat)abstract
- Free-floating car sharing services (FFCS) have been offered as a more flexible mobility solution than other car sharing services. FFCS users can pick up and return cars anywhere within a specified area in a city.The objective of this paper is to identify similar usage patterns of FFCS in different cities as well as city characteristics that make these services a viable option. The authors have access to real booking data for 32 cities in Europe and North America. Their study shows the share of daily car trips is negatively correlated to the utilization rate of these services. Also, the higher the congestion and the harder finding a parking lot, the lower the utilization rate of these services is in the cities. Moreover, our results suggest that FFCS services do not compete with public transport but are rather used in combination to it. These services are mainly used during midday and evening peak and the trips taken by these services are mainly chained trips.The clustering analysis shows that the trips are grouped into two or three clusters in different cities. The majority of clusters are the inner city clusters which contain a significantly higher number of trips than the clusters around other points of interest such as airports. © Conference Compass and Transportation Research Board
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| 7. |
- Habibi, Shiva, et al.
(författare)
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Success and Usage Pattern of Free-Floating Carsharing Services in Cities
- 2018
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Free-floating car sharing services (FFCS) have been offered as a more flexible mobility solution than other car sharing services. FFCS users can pick up and return cars anywhere within a specified area in a city.The objective of this paper is to identify similar usage patterns of FFCS in different cities as well as city characteristics that make these services a viable option. The authors have access to real booking data for 32 cities in Europe and North America. Their study shows the share of daily car trips is negatively correlated to the utilization rate of these services. Also, the higher the congestion and the harder finding a parking lot, the lower the utilization rate of these services is in the cities. Moreover, our results suggest that FFCS services do not compete with public transport but are rather used in combination to it. These services are mainly used during midday and evening peak and the trips taken by these services are mainly chained trips.The clustering analysis shows that the trips are grouped into two or three clusters in different cities. The majority of clusters are the inner city clusters which contain a significantly higher number of trips than the clusters around other points of interest such as airports.
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| 8. |
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| 9. |
- Habibovic, Azra, et al.
(författare)
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Current gaps, challenges and opportunities in the field of road vehicle automation
- 2014
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Ingår i: Proceedings of FISITA 2014 World Automotive Congress.
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Konferensbidrag (refereegranskat)abstract
- The aim of this study is to identify current research gaps, challenges, and opportunities in the field of vehicle automation. The study is based on a literature review. The review shows that the current research focuses mainly on improvements in sensing, actuation, and navigation systems. However, this study acknowledges a range of challenges in other areas that need to be addressed to facilitate possible benefits that vehicle automation may bring. In particular, the following challenges are highlighted: 1) understanding the transfer of control between the vehicle and the driver, and vice versa, 2) defining behavior of automated vehicles in relation to other road users (e.g., pedestrians), 3) identifying how to communicate the system reliability information to the drivers, and 4) clarifying the impact on societal values, i.e. what driver behaviors that will be considered as appropriate, or even acceptable. The work presented here is a part of the ongoing project Boundary Conditions for Vehicle Automation, co-financed by the Swedish Governmental Agency for Innovation Systems (VINNOVA) and carried out by SAFER-Vehicle and Traffic Safety Centre at Chalmers.
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| 10. |
- Olsson, Oscar, et al.
(författare)
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Lessons learned from electric cars in daily taxi operation in Gothenburg
- 2017
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Konferensbidrag (refereegranskat)abstract
- Shared mobility solutions consisted of an electric bike pool, an electric car pool, and electric taxi servicewas assumed to enable similar mobility flexibilities as owning a car. The concept was tested in Gothenburgfor about a year in the local ELMOB project. This article focuses on the feasibility of the electric taxi aspart of the shared mobility package. Both customers’ and drivers’ perspective were studied regardingchanges in their behavior and fulfillment of their mobility needs. Data collected from the vehicles showvehicle performance, usage patterns and charging behavior of the drivers. The results imply that policy andregulations which favor electric taxis are crucial for enabling electric taxis at a larger scale
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| 11. |
- Pettersson, Stefan, et al.
(författare)
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Demonstration och utvärdering av induktiv laddning
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Trådlös, induktiv, laddning skulle kunna ge elbilar ytterligare en, och kanskeavgörande, fördel gentemot fossilbränsledrivna genom att användarna i principaldrig behöver åka någonstans för att ”tanka”. Istället laddas bilarna enkelt ochbekvämt trådlöst utan sladd när de står parkerade.Teknologin i sig är inte komplicerad men tillämpningen för fordon i verklighetenär fortfarande i sin linda. Det finns därför behov av att förstå såväl de praktiskasom tekniska svårigheterna hur verkliga användare utnyttjar och upplever den nyatekniken. Av denna anledning initierades WiCh-projektet 2012 efter en förstudiesom förutsättningslöst studerade lämpliga lösningar för bekväm laddning.Projektet har, i världens fortfarande största enskilda fältstudie avinduktionsladdning, utrustat 20 personbilar i kommunal och enskild verksamhetoch följt upp användningen under ett och ett halvt års tid. Resultaten av studienvisar att trådlös laddning kan vara attraktiv jämfört med laddning med sladd, ochatt ladd-beteendet sannolikt kommer att förändras med trådlös laddning.Utrustningen levererades av den enda leverantör som finns på den öppnamarknaden, amerikanska Evatran Group. För att få tillstånd till en fältstudie iSverige genomfördes ett antal tekniska prov vilka också gav viktig kunskap tilltestorganisationer och tillståndsgivande myndigheter.
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| 12. |
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| 13. |
- Pettersson, Stefan, et al.
(författare)
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Large scale testing of wireless charging in Sweden
- 2016
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Ingår i: EVS 2016 - 29th International Electric Vehicle Symposium. - 9781510832701
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Konferensbidrag (refereegranskat)abstract
- Wireless charging has the potential to simplify charging of electric cars, a technology that is now tested on a larger scale in Sweden in an ongoing project denoted WiCh (Wireless charging of electric vehicles). Inductive wireless chargers have been installed in a total of 20 electric vehicles located in Sweden, which means that so far the study is the largest demonstration activity of inductively charged vehicles in the world. The technology will be demonstrated and assessed during a year, and the experiences gained so far are outlined in this paper.
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| 14. |
- Pettersson, Stefan, et al.
(författare)
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Parking support for inductive charging
- 2017
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Konferensbidrag (refereegranskat)abstract
- Inductive charging could give electric vehicles yet another competitive advantage over fossil-drivenvehicles in that users seldom or never have to think about refueling. However, when about to recharge thevehicle, the secondary, receiver coil must be precisely positioned above the primary, transmitter coil inorder to achieve high transmitted power and efficiency. Manually maneuvering a vehicle to this positionhas in our studies proven to be a challenging task, especially when using tight or public parking spaces.This article investigates the parking precision challenges connected with induction charging along withpossible solutions, including fully automated parking.
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| 15. |
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| 16. |
- Sprei, Frances, 1977, et al.
(författare)
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Comparing Elecytric Vehicles and Fossil Driven Vehicles in Free-floating Car Sharing Services
- 2017
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Ingår i: Proceedings of EEVC 2017.
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Konferensbidrag (refereegranskat)abstract
- In recent years, free-floating car sharing (FFCS) services have been offered as a more flexible option compared to traditional car sharing. FFCS allows users to pick up and return cars anywhere within a specified area of a city. These can be either electric or fossil driven vehicles. We analyze the difference in usage of these two types of vehicles. The analysis is based on a dataset consisting of vehicle availability data sampled between 2014 and 2016 for 9 cities with EVs in the FFCS fleet. We find that there is no statistical difference in how EVs and fossil driven FFCS vehicles are used. When it comes to charging of EVs two main strategies are identified: widespread “slow charging” versus tailored fast-charging.
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| 17. |
- Sprei, Frances, 1977, et al.
(författare)
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Free-floating car-sharing electrification and mode displacement : Travel time and usage patterns from 12 cities in Europe and the United States
- 2019
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Ingår i: Transportation Research Part D. - Oxford : Elsevier BV. - 1361-9209 .- 1879-2340. ; 71, s. 127-140
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Tidskriftsartikel (refereegranskat)abstract
- Free-floating car-sharing (FFCS) allows users to book a vehicle through their phone, use it and return it anywhere within a designated area in the city. FFCS has the potential to contribute to a transition to low-carbon mobility if the vehicles are electric, and if the usage does not displace active travel or public transport use. The aim of this paper is to study what travel time and usage patterns of the vehicles among the early adopters of the service reveal about these two issues. We base our analysis on a dataset containing rentals from 2014 to 2017, for 12 cities in Europe and the United States. For seven of these cities, we have collected travel times for equivalent trips with walking, biking, public transport and private car. FFCS services are mainly used for shorter trips with a median rental time of 27 min and actual driving time closer to 15 min. When comparing FFCS with other transport modes, we find that rental times are generally shorter than the equivalent walking time but longer than cycling. For public transport, the picture is mixed: for some trips there is no major time gain from taking FFCS, for others it could be up to 30 min. For electric FFCS vehicles rental time is shorter and the number of rentals per car and day are slightly fewer compared to conventional vehicles. Still, evidence from cities with an only electric fleet show that these services can be electrified and reach high levels of utilization.
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| 18. |
- Sprei, Frances, et al.
(författare)
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How can e-scooter better contribute to a sustainable transport system?
- 2023
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The eSPARK project examines the sustainability profile of the popular shared e-scooters through policy analysis, usage data analysis, surveys, and life cycle assessment. Policies and attempts to regulate e-scooters in Swedish and European cities are studied and discussed with stakeholders. The LCA-results suggest that factors such as how e-scooters are collected and distributed, and the total ridden kilometers have significant impact on their environmental impact. The project also suggests different methods that can support cities to predict the geographical area of the e-scooters and offers insights about how e-scooters are used in the cities. Usage data and the surveys show that they are used by active people in areas with a lot of activities, especially restaurants and clubs. Users are likely to have a driving license, to frequently use a car but also to have a monthly pass for public transport. Thus, escooters have a potential to mitigate congestion on roads and public transport but may lead to more traffic on bike infrastructure instead.
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| 19. |
- Williander, Mats, et al.
(författare)
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Company Cars as a Channel for Electrification of the Passenger Car Market
- 2018
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Konferensbidrag (refereegranskat)abstract
- Plug-in company cars can be a “fast lane” to reduce CO2 emissions in Sweden. since they constitute 20-25% of new car sales. For that to happen the following three enablers are crucial:1. That companies have car policies that make plug-in cars eligible. A change from a maximum purchase price to a maximum monthly cost has shown to be the way.2. A continuous and significant difference in fringe benefit tax value/monthly cost relative to a conventional company car.3. Destination charging possibilities at work places are important, primarily for those having PHEVs.
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| 20. |
- Yu, Anne, et al.
(författare)
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A user study on station-based EV car sharing in Shanghai
- 2016
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Ingår i: EVS 2016 - 29th International Electric Vehicle Symposium. - 9781510832701
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Konferensbidrag (refereegranskat)abstract
- There has been a trend in car sharing and especially electric car sharing over the last decade. This study aims at developing knowledge of users and searching market opportunities for the electric car sharing service EVCARD in Shanghai, China. EVCARD originates in the suburban Jiading district and is planning on expanding the business to the centre of Shanghai. Survey methods and tools have been applied in the study to acquire user data. The analysis was designed to answer research questions related to users' attitudes and expectations about the EVCARD service and to provide suggestions for system improvement.
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