Laboratory for Robotics and Engineering Systems

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Organizational Unit

Publications

Assessment of wireless charging impacts based on real-world driving patterns: case study in Lisbon, Portugal

Publication . Duarte, Gonçalo; Silva, André; Baptista, Patrícia

In the current transition to a smarter and more efficient transportation system, battery electric vehicle mileage and the time required for charging are still two main constraints that need to be overcome to enable a larger penetration of electric vehicles. Moreover, the few charging stations available are a consequence of the "supply and demand" problem. Consequently, wireless dynamic recharging can be a complementary solution to address the problems of light-duty electric mobility and an added-value towards autonomous vehicles. Consequently, this paper presents an innovative approach based on real world mobility patterns collected for a sample in the city of Lisbon, Portugal, to assess users' electric vehicle feasibility by assessing different recharging scenarios, comparing stationary and dynamic recharging scenarios. The results indicate that at least 15 % more drivers would be eligible to own an electric vehicle if wireless charging was available. Moreover, wireless charging reduces the range of battery used, with stationary charging requiring circa 3.2 times more battery range. The developed approach confirms that wireless dynamic recharging can significantly change the framework of current electric mobility limitations, reducing range anxiety issues, contributing to redesign electric vehicle battery capacity and overcome barriers in stationary charging deployment and availability.

2021-08Journal article

Restricted access

Systematic method for developing reference driving cycles appropriate to electric L-category vehicles

Publication . Watling, David; Baptista, Patrícia; Duarte, Gonçalo; Gao, Jianbing; Chen, Haibo

Increasingly, demanding environmental standards reflect the need for improved energy efficiency and reduced externalities in the transportation sector. Reference driving cycles provide standard speed profiles against which future developments and innovations may be tested. In the paper, we develop such profiles for a class of electric L-category vehicles, which are anticipated to play an increasing future role in urban areas. While such driving cycles exist for regular L-category vehicles, these may not be suitable in the case of electric vehicles, due to their power output limitations. We present a methodology for deriving these new driving cycles, developed from empirically deduced power relationships, before demonstrating their application under different assumptions on the terrain and vehicle characteristics. The applications demonstrate the feasibility of the method in developing appropriate driving patterns for alternative real-world contexts. On flat terrain, the adjustments made to cope with the power limitations of L-EV do not introduce significant differences in energy consumption, suggesting that the certification does not require extensive modification. However, when considering road slope, differences of up to 5% in energy use and up to 10% in regenerated energy were observed, showing the importance of the developed method for assessing vehicle performance in real-world driving.

2022-05-09Journal article

Open access

Including engine data for energy and pollutants assessment into the vehicle specific power methodology

Publication . Mera, Zamir; Varella, Roberto; Baptista, Patrícia; Duarte, Gonçalo; Rosero Obando, Fredy

Vehicle emission models are relevant for evaluating the performance of vehicle technologies and help in the definition of environmental policies. This paper presents an improved emissions modelling approach (named VSP+M) by combining the vehicle specific power (VSP) with load-regime engine maps for each VSP mode. The new modelling enabled to link tailpipe emissions to vehicle and engine operating conditions, obtained from real driving emission (RDE) tests and on-board diagnosis (OBD) data. The parameters for the sizing of engine maps were optimised by means of Pareto frontiers to solve the trade-off between the minimisation of RMSE and emission factor errors in urban sections and total RDE trips. The CO2 emission factors errors were reduced up to 63% and 45% for urban and RDE sections, respectively. The NOx emission factor errors were reduced up to 15%, maintaining the same RMSE levels. Optimal engine maps sizing was found for every tested vehicle and for each engine type to be applied in other vehicles. This study demonstrates the potential to address declinations of the conventional VSP model based on engine operation or proxies to those variables by using the proposed approach.

2022-04-01Journal article

Restricted access