Final Report Summary - EPSILON (small Electric Passenger vehicle with maximized Safety and Integrating a Lightweight Oriented Novel body architecture) Executive Summary:Larger and more densely populated urban areas are causing new challenges to mobility systems in terms of congestion as well as pollutant and noise emissions. Current passenger cars are actually over-sized for the typical urban transport task. The epsilon projects aims to conceptualise and prototype a small electric vehicle (SEV) concept specifically designed for urban areas in 2020-2025.In WP1 a business case study for the epsilon vehicle concept was deployed. In particular customer expectations were translated into overall vehicle specifications, including a first estimation for the target price of an electric light vehicle and a production volume forecast. In WP2 detailed targets for the key aspects safety, lightweight, driving dynamics and energy consumption were defined and feasibility was investigated. The full vehicle concept was developed including the positioning of passengers, packaging of the selected components and styling features according to the specific vehicle mission. Within WP3 the development for all required vehicle components was carried out. The technical concepts for body and interior, chassis and drivetrain and the performance targets from WP2 formed the basis of all development and design work. In detail this comprised:• Full vehicle integration • Body and interior • Chassis and suspension • Drivetrain The result of the development process is a comprehensively engineered concept for the epsilon vehicle, providing all necessary data for the prototype built in WP4. A full running prototype was built up. All systems were brought into service and thus been tuned to harmonise. In addition two vehicle structures were manufactured for safety validation testing of the vehicle structural design. The prototypes were tested concerning the epsilon targets in WP5. The safety was tested by a full front width rigid barrier test on a front sub-structure as well as on a full rolling chassis body prototype. The safety level was considered to be satisfying with regard to a Euro NCAP four star rating. The restraint systems were tested in sled tests. The pedestrian safety was evaluated in a fully virtual approach applying the finite element method (FEM).The drivetrain including battery and the heating, ventilation and air conditioning (HVAC) system was tested according to different driving cycles in a first step on a test rig as a sub-system. After integration into the running vehicle the system was tested again on a roller dynamometer with assumptions made for the drag resistance. Again the target values could be achieved.Also tests on the vehicle chassis were carried out using the driving prototype. A comprehensive test programme allowed the evaluation of the driving dynamics. The test showed that the vehicle requires a reasonable steering effort for a car without electric steering box but the lack of power assistance will be noticed. On the other side, the vehicle has an overall better lateral dynamics performance than a comparable reference car. The longitudinal dynamics were considered to be acceptable for a vehicle without anti-locking braking system.Project Context and Objectives:Larger and more densely populated urban areas are causing new challenges to mobility systems in terms of congestion as well as pollutant and noise emissions. epsilon will focus on the development of an innovative electric vehicle concept specifically designed for the typical transport tasks in urban areas. The epsilon vehicle will be considerably lighter, more energy efficient and require less road space than today's sub-compact cars, still offering the same level of safety. Compared to powered two-wheelers, epsilon will provide higher safety, transport capacity and driving comfort in all weather conditions. Offering at the same time an appealing driving performance at affordable costs, the epsilon vehicle will address not only the ecological and societal, but also the economic dimension of sustainable mobility, defining a new vehicle class by closing the gap between poweredtwo-wheelers, ultra light vehicles (L7e) and conventional passenger cars (M1).Making use of state-of-the-art components and integrating highly innovative components and systems from technology and component focused research activities, the epsilon project brings together some of the top automotive design & engineering companies and institutes in Europe and most advanced technologies. Expected results and key features are:• Complete business case• At least two seats• All weather comfort accessories• Maximum crash safety (legislation and NCAP)• Weight < 600 kg• Attractive driving performance• Acceleration 0-100 km/h in < 10 s• Purely electric range > 150 km• High energy efficiency (< 80 Wh/km)Project Results:The task in WP1 was to deploy a business case study for the epsilon vehicle concept to set a framework with regard to social and technological scenarios for 2020 and beyond. In particular customer expectations had to be translated into overall vehicle specifications, including a first estimation for the target price of an electric light vehicle and a production volume forecast. In WP2 detailed targets for the key aspects safety, lightweight, driving dynamics and energy consumption have been defined and feasibility has been investigated by means of pre-engineering studies. Best-suited technologies for all vehicle functions have been selected, combining all required components in the best possible way. The full vehicle concept has been developed including the positioning of passengers and packaging of the selected components. The package shows a unique approach of a 2+1 concept based on an approach of two 95th percentile male in the front and one 5th percentile female in the rear. The design development has been based on the vehicle concept and relevant styling features according to the specific vehicle mission. The realisation of an agile, safe and easy to use urban vehicle is the primary objective. The development for all required vehicle components has been carried out within WP3. The technical concepts for body and interior, chassis and drivetrain and the performance targets from WP2 formed the basis of all development and design work. In detail this comprised:• Full vehicle integration: A virtual car has been built up including all sub-systems of the vehicle. Besides the general domains like body, chassis, drivetrain, battery, HMI, seating this included as well the global harnesses for 12 V and high voltage system. All components have been modelled using computer aided design (CAD). One major part of this task was to organise the model and to define a bill of materials (BOM) to facilitate the cooperation between the partners and monitor the development process. Furthermore, it was possible to ensure the compatibility of all sub-systems with these tools and to monitor the weight• Body and interior: A CFRP-aluminium space frame body structure has been designed based on the interior and exterior styling as well as package concept defined in WP2. The structure has been developed with respect to the set of crash and static load cases defined in WP2. All of them have been analysed in finite element (FE) simulations. The required passive safety has further been achieved by developing restraint systems based on simulations using the geometry, crash pulse and intrusions from the full vehicle crash simulations. Special focus was set on the battery system. The safety of this structure was also analysed in sub-component simulations. The pedestrian safety has been evaluated in a number of FE simulations considering all relevant Euro NCAP situations.• Chassis and suspension: Based on existing series components a chassis structure for the epsilon vehicle has been developed. The carry-over parts have been combined with special parts to a system that satisfies the targets given on driving performance and urban agility. All relevant driving manoeuvres have been simulated using multi-body models. Special focus was set on reducing the mass of the chassis. In this regard a novel CFRP-steel omega rear axle concept has been developed that is significantly lighter than a standard steel solution. This structure has been designed and optimised using extensively FE analyses.• Drivetrain: The focus in development regarding drivetrain components was to achieve the key performance requirements of the epsilon vehicle. Therefore, several layouts of the drivetrain with off-the-shelf components have been investigated. A concept including the electric motor, high voltage (HV) battery, energy management system, power electronics, mechanical transmission and the cooling system has been developed to fulfil the challenging driving performance. Therefore, the investigation aimed not only at the masses of the individual components, but also on the specific energy demand and efficiency. To ensure the safe and efficient usage of the drivetrain a thermal management system has been developed. Moreover, the vehicle control strategy has been design and implemented. Here efficiency was the main goal of the development. Especially the control of regenerative braking has been in the focus to achieve high values of recuperation on the one hand and provide a comfortable one pedal driving feeling. The system has been modelled and investigated based on Matlab/Simulink simulations concerning energy consumption and driving range for different cycles. The result of the development process is a comprehensively engineered concept for the epsilon vehicle, providing all necessary data for the prototype built in WP4. A full running prototype has been built up in close conformity to the virtual vehicle incorporation all components of body, chassis, drivetrain, HMI, seating and restraint systems as well as exterior and interior cladding. All systems have been brought into service and thus been tuned to harmonise. In addition to the running prototype vehicle, two vehicle structures have been manufactured for safety validation testing of the vehicle structural design. The built-up prototypes have been tested concerning the epsilon targets in WP5. The safety has been tested by a full front width rigid barrier test on a front sub-structure as well as on a full rolling chassis body prototype. The safety level was considered to be satisfying with regard to a Euro NCAP four star rating. Further the test results served as basis for the validation of the crash simulation model which was used to evaluate the other crash load cases of Euro NCAP as well as for the rear and overrun safety. The restraint systems were tested in sled tests considering the crash pulses from crash tests and simulations. As the exterior of the vehicle could not be produced as designed for budget reasons (tooling costs higher than overall prototyping budget) the pedestrian safety has been evaluated in a fully virtual approach applying the finite element method (FEM).The drivetrain including battery and the heating, ventilation and air conditioning (HVAC) system has been tested according to different driving cycles in a first step on a test rig as a sub-system. For the driving resistance coefficients assumptions have been made. It was proven that the system is capable to achieve the targets of the project. After integration into the running vehicle the system was tested again on a roller dynamometer with assumptions made for the drag resistance. Again the target values could be achieved.Also tests on the vehicle chassis were carried out using the driving prototype. A comprehensive test programme allowed the evaluation of the driving dynamics. The test showed that the vehicle requires a reasonable steering effort for a car without electric steering box but the lack of power assistance will be noticed. On the other side, the vehicle has an overall better lateral dynamics performance than a comparable reference car. The longitudinal dynamics were considered to be acceptable for a vehicle without anti-locking braking system.Potential Impact:The objective of work package WP 6 was to broaden the impact of the project’s results by appropriate documentation, publication and promotion towards different stakeholders. Therefore WP 6 communicated the epsilon objectives and outcomes to a wide range of target groups. The overall aim was to spread the project findings to a wide group of industry actors from the transport and energy sector, to public actors, in particular urban transport authorities and the wider public. Being related to the SEAM cluster of EU funded projects (SafeEV, ENLIGHT, ALIVE, MATISSE) a basis for a high degree of visibility was set. Input and results of related projects were highlighted, pointing out the joint research approach in the European Green Cars Initiative. First, in WP6 a dissemination and exploitation strategy for the epsilon project was developed. This strategy was based on three main pillars (website, publications and dissemination events including a road show).The project website featuring the project overview, approach and latest results has been set up as the project’s main point of reference to obtain detailed information on its objectives, partners, results, recommendations and project deliverables. A project newsletter with a subscribe function is also be available through the website. Within the project phase four issues of the newsletter have been published. Additional issues about the final results will follow after the finalisation of the project.Apart from this digital information material, a project leaflet was developed by FKA, presenting the project’s main objectives and expected results at a glance. This is targeting a wide range of stakeholders and has been used as the project’s identity card to the outside world :Contributions at conferencesDue to the variety in different target groups, the strategy has been to present the results at different scientific conferences with different focus and audience. In total, the epsilon project has been presented at seven scientific conferences or symposia.• Eckstein, L.: The Future Car Body – Diversity of Architectures and Materials, Aachen Body Engineering Days 2014, Aachen, Germany, September 23rd 2016• Seidel, K.: epsilon – Vehicle and structural concept for an urban EV, FutureCarBody 2016, Bad Nauheim, Germany, June 8th 2016• Stein, J.; Seidel, K.; Faßbender, S.; Urban, P.; Eckstein, L.: epsilon – Small Vehicle Concept with Optimised Safety and Innovative Lightweight Body Architecture, Aachen Body Engineering Days 2016, Aachen, Germany, September 21st 2016• Seidel, K.: epsilon - A New Vehicle Class for Future Urban Mobility Needs, 25th Aachen Colloquium Automobile and Engine Technology, Aachen, Germany, October 11th 2016• Becker, P.: Entwicklung einer Leichtbauhinterachse in Metall-Faserverbundbauweise (German), Bondexpo-Kongress 2016, Stuttgart, Germany, October 10th 2016• Stein, J.; Seidel, K.; Matheis, R.; Faßbender, S.; Urban, P.; Eckstein, L.: epsilon – Small electric Vehicle Concept with an Innovative Lightweight Body Structure, FLK Mitgliederversammlung, Lippstadt, Germany, November 19th 2016• Matheis, R.; Stein, J.; Seidel, K.; Faßbender, S.; Urban, P.; Eckstein, L. epsilon – Small electric Vehicle Concept with an Innovative Lightweight Body Structure, Opel Innovation Friday, Rüsselsheim, Germany, November 25th 2016ExhibitionsAs a complement to the conference presentations, the project results and the physical demonstrators developed within epsilon have been displayed at a number of exhibitions. • JEC 2015, Paris, France, 10th to 12th March 2015• JEC World 2016, Paris France, 8th to 10th March 2016• Aachen Body Engineering Days, ika Aachen, 20th to 21st September 2016• Final SEAM Cluster Workshop, ika Aachen, 22nd September 2016• Grazer SafetyUpDate, VSI Graz, 27th to 28th 2016• Aachen Colloquium Automobile and Engine Technology, Eurogress Aachen, 11th to 13th October 2016• EARPA FORM Forum, The EGG Brussels, 19th October 2016• 11th European Trade Fair & Forum for Composites, Messe Düsseldorf, 29th Nov. to 1st December 2016Road ShowA road show was organised in which the vehicle is showcased in different European regions. The first event has been held in Aachen on February 22nd 2017. The goal of the road show is not just to raise awareness but also to validate the acceptance of the vehicle by potential customers Questionnaires have been prepared people in order to gather their feedback. Preparation and analysis of the questionnaires has been supported by experts with a background in psychology. The results for the survey in Aachen 95 questionnaires have been received.The road show is ongoing. The vehicle is already scheduled to be presented on seven events:- JEC 2017, Paris, France, 14th to 16th March 2017- Automotive Engineering Congress 2017, Nuremberg, Germany, 30th to 31st May 2017- Graz Symposium Virtual Vehicle – Smart Mobility, Graz, Austria, 27th to 28th June 2017- bonding Automotive Day, Aachen, Germany, 5th July 2017- Aachen Body Engineering Days 2017, Aachen, Germany, 19th to 20th September 2017- E-Mobility Play Days, Spielberg, Austria, 29th to 30th September 2017- A3PS Annual Conference – Eco-Mobility 2025plus, Graz, Austria, November 2017WorkshopsAs an important mean of exchange of information and a good complement to conference presentations and project meetings, two workshops have been arranged during the project.epsilon has been presented in a dedicated presentation at the SEAM Cluster workshop “Innovationen für den Fahrzeugleichtbau – Aktuelle Forschungsergebnisse aus sechs EU-Projekten” at Fraunhofer LBF in Damstadt on January 15th 2016.At the end of the project (22nd September 2016), and in direct connection to the Aachen Body Engineering Days, a final exhibition and a workshop was organised at IKA to present the project’s results to the respective target groups envisaged. This event was jointly arranged between the projects epsilon, ALIVE and ENLIGHT since it was thereby believed to be more attractive to attendants due to the complementarities between the three projects. The event was free of charge and included a showcase of the prototypes developed within the projects. The workshop attracted in total 90 participants (including project partners) and was successful in that the main results were disseminated and discussed, and that the body structure and rear axle were presented as physical prototypes.List of published trade magazine papersPublications in the specialised and general press can increase the potential of the project to reach out to the key target groups in Europe and beyond. Published papers also ensures transfer and preservation of knowledge gained within the project. • N.N.: Hybride Bauweise reduziert Gewicht (German), Produktion – Technik und Wirtschaft für die deutsche Industrie, 48/2016, verlag moderne industrie, Landsberg/Lech, Germany• Stein, J.; Matheis, R.; Faßbender, S.; Seidel, K.: Elektrisches Kleinstfahrzeugkonzept epsilon mit Leichtbaukarosserie, ATZ, 02/2017, Springer Vieweg, Wiesbaden, GermanyOther Publications• 19.10.2013 Press release by LEC• 13.02.2014 Project summary on EGVI website • 10.03.2014 Press release by VIF• Presentation for EGVI slideshow at TRA 2016 conference, Warsaw, Poland, 18th to 21st April 2016• Press release: „Neue hybride Leichtbauhinterachse für E-Fahrzeuge“ (German), in: Automobil Industrie 16.08.2016 distributed online, http://www.automobil-industrie.vogel.de/neue-hybride-leichtbauhinterachse-fuer-e-fahrzeuge-a-545787/• Press release: „Fraunhofer LBF entwickelt hybride Leichtbauhinterachse“ (German), in: Springer Profesional 16.08.2016 distributed online,https://www.springerprofessional.de/leichtbau/fahrwerk/fraunhofer-lbf-entwickelt-hybride-leichtbauhinterachse/10586340List of Websites:http://www.epsilon-project.eu/
