On 24th October 2011, Cidaut started one exciting jorney on board a Nissan Leaf. Since that day, the vehicle has been used as a laboratory for understanding the users’s acceptance, the influence of the weather and the driving style on the battery behaviour, the regenerative braking efficiency and so many other issues that have allowed our sustaineble movility and intelligent transport department to fix important knowledge to build many.
All the vehicle movements have been tracked to understand the influence of driving profiles, roads orography, weather conditions, battery temperature and vehicle payload on energy consumption. Also the charging processes have been monitored to evaluated the influence of low charging vs fast charging, battery temperature and voltage and current evolution along the charging.
Braking system has been instrumented to understand the influence of driving style and battery state of charge on regenerative braking working. Noise measurements in the interior and exterior of the vehicle have been performed and on board thermal analysis has allowed to understand some charateristics of the HVAC system.
The vehicle has been used by more than 200 drivers that have completed surveys and have participated in interviews to better understand the initial users’ acceptance to the electric vehicle use. This information has been valuable for Cidaut in order to advance in the evolution of several projects related not only with the electric vehicle, but also with the connected one.
The COVID-19 has forced to celebrate the II Foro Iberoamericano de la Energía on-line. In this edition, Cidaut has been invited to show its know-how and experience in the development of solutions for sustainable mobility. The presentation made by the Research and Development Center has been focused on the methodology followed in the last twelve years to complete the whole path from the idea to the manufacturing of a safe urban electric vehicle.
The first point of the presentation was to highlight the support of the European Commission through the different funding programs and the great contribution of the different and numerous partners involved in the different project presented. Although Cidaut has worked in different solutions for the vehicle structures, mainly CFRP, light alloys and AHSS, in this case the solution based on Advanced High Strength Steel was presented. This working line started on 2012 with the design of a safe urban vehicle (PLUS-MOBY Project) and its related infrastructure. The vehicle’s power train consisted in two motor one per axle with and enhanced dynamic behavior and improvement crashworthiness for lateral and frontal crashes. Both the vehicle and the infrastructure used the photovoltaic energy to reduce de carbon footprint with cells in the roof of the vehicle and in the infrastructure, also the batteries available in the infrastructure were compatible with the batteries in the car to allow battery swapping.
Along Steel S4 EV Project, the vehicle structure is optimize paying special attention to the cutting and welding processes of the structure and the assembly of the vehicle as a whole. The aim is to make a clean safe vehicle easy and cheap to be manufactured. The design of the micro-factory where the solution achieved in Steel S4 EV can be produced is been tackled in Avangard Project, where the main objective is the definition of a 4.000m2 plant where different configurations of the vehicle (van, pick-up, enlarged van, standard,…) can de produced with an investment 90% lower in comparison to a standard vehicle factory.
Finally, the product will be improved thanks to the integration of automated driving capabilities that will be implement in the coming project MULTI-MOBY.
The European Project STEEL S4 EV, funded by the Research Fund for Coal and Steel (RFCS) has successfully completed the first half of research and development activities. This item has coincided in the time with the presentation of the design of the second vehicle of the project: the threewheeler. The design presents several parallelism with the four wheels vehicle defined in the first stages of the project. The objectives behind this similarity are multiple, on one hand to simplify and make cheaper the manufacturing process, making possible to assembly both vehicles in the same assembly line, on the other hand to warranty the same level of integral safety as in the four wheels vehicle.
The solution adopted for the threewheeler is a two in line seats vehicle, with one wheel in the front, the electric motor in the rear axle, under the rear seat, and the battery pack under the front seat. The structure of the vehicle is made of different grades of Advanced High Strength Steel, where the geometry of the tubes and their thickness have been optimized to maximize the energy absorption in the frontal part of the vehicle and to warranty the undeformability of the safety cell, where the occupants are allocated.
In order to get this target, in parallel to the optimization of the crashworthiness through the finite elements methodology, advanced research is been done about the optimization of the welded joints of the advanced high strength steels. In every welding joint, not only the weld seam, but also the heat affected zone, suffers an important loss of mechanical properties due to the melting and uncontrolled cooling of the material. In the case of the Advanced High Strength Steels, this loss of properties is still more critical due to the special characteristics of the material. One of the objectives of STEEL S4 EV Project is to optimize the welding parameters, to improve the heat treatment of the joints in order to improve the static, dynamic and fatigue behavior of the welding joints of the complete structure of both vehicles, the three wheeler and also the four wheels vehicle.
In April, it has been held the Midterm Review Meeting of STEEL S4 EV Project, between the Project Coordinator, the Project Officer and some technical experts from the TGA 4. After a successful meeting, the activities of the project go on with the focus on the prototype manufacturing and the preparation of the different tests.
The international Symposium on Impact Engineering, ISIE 2019, aims to establish a professional dialogue between cultures, scientists and industry engineers on the field of experimental and computational mechanism with focus on impact and other dynamic problems.
The 2019 edition was hold in Gmunden in Upper Austria on 2-5th July 2019, the location offers a relaxed atmosphere, a beautiful environment, and a high-class service for the conference. Cidaut was there as Coordinator of Steel S4 EV project, presenting the preliminary results obtained in this project funded by the European Commission in the frame of the H2020 initiative. The presentation was focused on the crash results taking advantage of the participants’ expertize in impact engineering, mainly coming from Asia and Europe, but also with representative from America. The advances on the vehicle structure design and the evolution of the crash behavior from the starting of the project to the nowadays situation was presented.
The project has covered the first year out of three, its main target is putting high strength steels at the forefront of a new trend in electric vehicles: light vehicles with three or four wheels that comply with crash regulation and with more restrictive Euro NCAP demands. Weld joint design and welding methodologies research to maintain the material properties in the weld area, assuring the robustness and long term durability.
Cost effective low-investment manufacturing will be achieved by a modular and flexible structural design: a complex 3D skeleton frame of welded tubes, bent with high accuracy using programmed laser cuts will enable the production of different vehicles sharing the same tooling.
The six partners of the Consortium (Cidaut, IFEVS, Belgian Welding Institute, Lulea Technical University, Magnetto Automotive and thinkstep) have met at thinstep’s facilities in Stuttgart to discuss about the evolution of the project. STEEL S4 EV aims at putting high strength steel at the forefront of a new trend in electric vehicles: light vehicles with three or four wheels that comply with crash regulation and with more restrictive Euro NCAP demands. Weld joint design and welding methodologies research to keep material properties along the joints assuring robustness and long term durability. To do this cost competitively low investment manufacturing will be achieved by a modular and flexible structural design: a complex 3D skeleton frame of welded tubes, bent with high accuracy using programmed laser cuts will enable different vehicles sharing the same tooling.
Representatives of the six partners involved in STEEL S4 EV project
This is the First Steering Committee Meeting and it has been hold in the fifth month of the project. All the project activities are running in accordance to the timing. This time special attention has been paid to the input data needed for the Life Cycle Assessment.