Search results for " Vehicles"
showing 10 items of 181 documents
Between the Megalopolis and the Deep Blue Sky: Challenges of Transport with UAVs in Future Smart Cities
2019
International audience; With the rapid increase of the world's urban population, the infrastructure of the constantly expanding metropolitan areas is undergoing an immense pressure. To meet the growing demands of sustainable urban environments and improve the quality of life for citizens, municipalities will increasingly rely on novel transport solutions. In particular, Unmanned Aerial Vehicles (UAVs) are expected to have a crucial role in the future smart cities thanks to their interesting features such as autonomy, flexibility, mobility, adaptive altitude, and small dimensions. However, densely populated megalopolises of the future are administrated by several municipals, governmental and…
State Estimation of a Nonlinear Unmanned Aerial Vehicle Model using an Extended Kalman Filter
2008
An Extended Kalman Filter is designed in order to estimate both state variables and wind velocity vector at the same time for a non conventional unmanned aircraft. The proposed observer uses few measurements, obtained by means of either conventional simple air data sensors or a low cost GPS. To cope with the low rate of the GPS with respect to the other sensors, the EKF algorithm has been modified to allow for a dual rate measurement model. State propagation is obtained by means of an accurate six degrees of freedom nonlinear model of the aircraft dynamics. To obtain joint estimation of state and disturbance, wind velocity components are included in the set of the state variables. Both stoc…
Electric Mobility in Portugal: Current Situation and Forecasts for Fuel Cell Vehicles
2021
In recent years, the growing concern for air quality has led to the development of sustainable vehicles to replace conventional internal combustion engine (ICE) vehicles. Currently, the most widespread technology in Europe and Portugal is that of Battery Electric Vehicles (BEV) or plug‐in HEV (PHEV) electric cars, but hydrogen‐based transport has also shown significant growth in the commercialization of Fuel Cell Electric Vehicles (FCEV) and in the development of new infrastructural schemes. In the current panorama of EV, particular attention should be paid to hydrogen technology, i.e., FCEVs, which is potentially a valid alternative to BEVs and can also be hybrid (FCHEV) and plug‐in hybrid…
Energy consumption model of aerial urban logistic infrastructures
2021
In the last decade, logistic systems based on small aerial vehicles (drones) have become attractive for urban delivery operations as a sustainable alternative to ground vehicles because they are not affected by the congestion of the road network, thus allowing for faster and more reliable services. Aerial logistic systems, however, require a substantially different approach to operations management and need specifically designed supportive infrastructures. While the research on urban aerial delivery mostly focuses on the optimization vehicle operations, the appropriate design of supportive infrastructures is seldom considered. This paper focuses on the energy efficiency of aerial logistic s…
Voltage-Based Droop Control of Electric Vehicles in Distribution Grids under Different Charging Power Levels
2021
If left uncontrolled, electric vehicle charging poses severe challenges to distribution grid operation. Resulting issues are expected to be mitigated by charging control. In particular, voltage-based charging control, by relying only on the local measurements of voltage at the point of connection, provides an autonomous communication-free solution. The controller, attached to the charging equipment, compares the measured voltage to a reference voltage and adapts the charging power using a droop control characteristic. We present a systematic study of the voltage-based droop control method for electric vehicles to establish the usability of the method for all the currently available resident…
Interior Permanent Magnet Synchronous Machine Drive Powered by Fuel Cell for Automotive Applications
2020
Electric vehicles represent an optimal solution for the reduction of pollution in urban areas. In particular, the Fuel Cell (FC) technology is a promising solution especially for its charging times and zero CO2 direct emissions. The paper addresses the design and performance study of an Interior Permanent Magnet Synchronous Machine (IPMSM) drive powered by fuel cell for automotive applications. The IPMSM drive is powered by the use of 5,5 kW FC unit and it is composed of two DC-DC power converters and one inverter. In detail, a test bench has been carried out for the evaluation of the performances of each IPMSM drive conversion stage. Moreover, in order to simulate automotive working condit…
Electric vehicles and psychology
2021
The popularity of electric vehicles is evidenced by the broad range of manufacturers presenting new models of plug-in hybrid and battery vehicles. However, the success of the revolution or, rather, the rebirth of electric vehicles, is hanging by a thread, as it lacks the involvement of a large number of users, and many psychological mechanisms hinder it. What are users’ true feelings about this new world of vehicles? Are people ready for the fifth level of automation, i.e., fully automatic driving and the absence of the driving position? The purpose of this paper is to present and discuss the psychological aspects that influence the adoption of electric vehicles. Topics such as the chicken …
Psychosocial and environmental correlates of active commuting for university students.
2009
Abstract Objective To examine psychosocial and environmental correlates of active commuting to university (ACU) and explore its association with overall physical activity among college students. Methods The sample included 518 students (mean 22.4 years; 59.7% female) from two universities in Valencia, Spain. Weekly estimations of energy expenditure from ACU and total physical activity were obtained. Socio-economic status, self-efficacy, barriers to active transport, access to car and motorbike, access to public transport, walking and cycling facilities and distance to university were assessed. Data were collected April and May of 2009, using a self-administered survey. A structural equation…
Risk exposure to vibration and noise in the use of agricultural track-laying tractors.
2016
Human exposure to mechanical vibration may represent a significant risk factor for exposed workers in the agricultural sector. Also, noise in agriculture is one of the risk factors to be taken into account in the evaluation of workers’ health and safety. One of the major sources of discomfort for the workers operating a tractors is the noise to which they are exposed during work. The aim of this study was to evaluate the risk of exposure to whole-body vibration for the operator driving track-laying tractors in vineyard orchard and the noise level. The experimental tests were performed with six different track-laying tractors coupled with the same rototilling machine. The results showed that…
Acceptance of truck platooning by professional drivers on German highways. A mixed methods approach.
2020
Abstract Truck platoon driving is a current branch of automated driving, which has the potential to radically change the work routine of professional drivers. In a platoon system, one truck (semi-)automatically follows a lead truck with a reduced distance, which produces significant savings in fuel and enables better traffic flow. In a current application of truck platoon driving, the following vehicle operates at level-2 automation. Thus, the driver of the following truck merely has to supervise the semi-automated system, which takes over steering and speed control when engaged. Level-2 truck platoon driving had not been tested with professional drivers in real traffic before. We hypothesi…