TechFak EcoCar
TechFak EcoCar is an interdisciplinary group project initiated by the Chair for Electronic Components at the Friedrich-Alexander University Erlangen-Nürnberg (FAU). It deals with issues relating to the efficient use of energy in vehicles. The project is aimed at students from the technical faculty at FAU. In particular, the subjects of electrical engineering, electronics and information technology, mechatronics, energy technology, mechanical engineering, materials science and computer science are addressed.
The theming of environmentally conscious vehicle concepts gives the participants space for their own ideas and the opportunity to master challenges. Students work independently to develop future-oriented solutions and apply the knowledge they have learned in their studies to implement practical applications. As an interdisciplinary group project, the “TechFak EcoCar” aims, among other things, at promoting the next generation of students.
In the implementation of the project, Fraunhofer IISB is providing technical expertise in the field of power electronics and providing an electrically powered vehicle as a test platform.
Planning and goals
As part of the “TechFak EcoCar” project, new, energy-efficient concepts for electric vehicles are being researched by students from the technical faculty. The work resulting from this is carried out both within the framework of study achievements (e.g. Bachelor and Master theses) and through the students' own initiative. Here, based on the results of computer simulations, the students redesign the electric drive train according to the current state of the art. This is also done taking into account the requirements of the motor vehicle, for example safety, range and maximum speed.
The design includes the complete electric drive train, the energy and vehicle management, the power converter and the energy storage. The design and manufacture of the designed assemblies are based on this design. The components are first evaluated under laboratory conditions and then integrated into the test platform. Measurement data recorded during driving enable the simulation models to be checked and allow statements to be made about the energy savings actually achieved through the conversion. The knowledge gained flows into further optimization of the vehicle concept and the individual components.
The respective working points from the technical subject areas go through several project phases. Interested students can experience the entire value chain of a development process from the idea on the drawing board to the first prototype tests and the finished assembly in the vehicle. The project team currently consists of around 15 students.
Previous projects
EcoCar project
The "EcoCar" project started in 2008 deals with converting a Citroën AX from a conventional drive train to an electric one. The team concentrated on the most important main components.
The internal combustion engine of the AX was replaced by a self-designed electric motor. A new housing with integrated liquid cooling and integrated double converter was specially designed for this. More self-designed components of the new powertrain, the drive shafts and the associated planetary gear . The entire drive unit is characterized by its compact design and the common cooling circuit.
The conversion from a combustion engine to an electric motor also brings with it a new type of energy source. The fuel tank is no longer necessary and is replaced by six battery modules. Each module consists of twelve lithium-ion cells (LiFePO 4 ) with an energy content of approx. 1.7 kWh. The energy content of the entire storage system is therefore around 10.3 kWh.
Vehicle communication was also newly developed. In the vehicle, the individual components communicate via a CAN bus . Since the vehicle platform of the AX did not have a CAN interface in its original state, an adapter board was developed that transmits the analog and digital signals from the vehicle to CAN messages.
ElMo project
After completion of the “EcoCar” project, the next project, called “ElMo”, was started in early 2014. The students are pursuing a strategy similar to that in the “EcoCar” project. However, the vehicle to be modified is no longer a car, but a motorcycle. An Aprilia RXV 550, which is equipped with a self-developed electric drive train, serves as the basis .
A permanent magnet synchronous machine with an output of 14 kW is used as the motor . The two-stage gearbox provides a total reduction ratio of 1: 2.5 and is housed in a compact drive unit together with the motor and converter that we developed ourselves.
The vehicle's energy storage system consists of 216 lithium-ion cells (LiNiMnCo) that are combined in three battery modules . The battery pack has an energy content of 1.92 kWh and supplies a nominal voltage of 43 V.
As in the previous project, vehicle communication takes place via a CAN bus. The communication interface is a novelty. It is used to embed the motorcycle in vehicle-to-X communication. This describes the wireless data and information exchange between a vehicle and its surroundings. Vehicle-to-X communication can be divided into four areas: vehicle-to-vehicle communication, vehicle-to-infrastructure communication, car-to-enterprise communication and car-to-home communication .
Project Silver
At the beginning of 2018, the follow-up project to the ElMo project and thus the team’s current research topic began; the "SILVER" project . The acronym "Silver" stands for " S enkrecht-starting, i ntelligent, autonomous and l fear swaged capable V ersuchsplattform an e lektrischen R otorfluggeräts". As the name implies, this project expands the previous research direction of the electrification of vehicles with the field of aviation and the development of autonomous flying robots. The team develops its own solutions for control and regulation, as well as battery and battery management, missile development and long-range communication. The aim is to set up a functional research platform with which developments in sensor technology and communication can be tested.
For this purpose a concept of a modified hexacopter was designed, which combines 2 different flight characteristics in one model. Since flight robots in conventional designs usually operate in a rather inefficient hovering flight, flight times and ranges remain very limited, but the locations are very flexible. Hovering flying robots, on the other hand, achieve very long ranges, but require a runway, as the motors usually do not allow a vertical take-off due to their low power.
The concept developed in the team combines these two flight modes and thus enables vertical take-off and landing, as well as the transition to an efficient gliding flight. For this purpose, a missile with large wings was built for gliding, which contains two larger motor / propeller pairs at the rear for take-off and landing, as well as four smaller motors at the front for attitude control in hover flight and for generating thrust in gliding flight.
The control is based on a Pixhawk 2.1, by adding a companion computer, a multitude of new functions for the acquisition and processing of further data are possible. The development of the subcomponents from the various areas continues, the first flight tests under real conditions are planned for the end of 2018.