This contrast is difficult to reconcile: In electric cars, the range should be large, at the same time you expect responsive performance. Ergo both batteries and the motor are getting bigger. Even that drives the price up, added expensive lightweight materials, and then to reduce the total weight again. A vicious circle then? Researchers at the Technical University of Munich show now at the trade fair eCarTec in the Bavarian capital, their approach to affordable electric car: the Visio.M.
The Visio.M was devised in collaboration with experts from the industry ( BMW, Daimler and Continental), financially it was since 2012, around 7.1 million Euros from the Federal Ministry of Research. The result is a 1.55 meter wide and 1.31 meters high two-seater with a drag coefficient of 0.24. The striking feature is the very narrow tires in size 115/70 R16.
The range of the Visio.M give its creators at around 160 km, the maximum speed is 120 km / h. For comparison: An electric Smart is only slightly faster, but has a continuous output of 35 kilowatts. Contrast, the Uni - car to meet only 15 kilowatts (equivalent to 20 PS ). The equipment includes networked infotainment, but also steering wheel and heated seats.
Its energy storage is located behind the seats, a lithium-ion battery with a capacity of 13.5 kilowatt-hours. He weighs 85 kilograms and is can be charged in three to four hours from a wall outlet. Emphasizes the low weight of only 450 kg of Visio.M is ( without battery ). For comparison, the electric Smart is with batteries nearly a ton, the BMW i3 brings it to 1.2 tonnes.
The passenger compartment of the Visio.M consists of CFRP, in front and rear chassis and the roof frame is aluminum used. All panels are made of specially coated polycarbonate. Nevertheless, the passenger should be especially safe by a multi-piece monocoque construction. There is also a 360 - degree detection of the vehicle environment using radar and camera sensors. The bumper and in the doors, there are novel structure in tubular form airbags that protect the car from the outside.
In addition to the normal belt connects a two - point belt additional occupants optimally with the seat. Event of a side impact, the driver or passenger is pushed with the help of his seat inside. Speaking of slide: The seats are variable only in height, but the pedals are adjustable. Elements such as the air conditioning or the radio are bundled in a likewise adjustable, central touchscreen. Basis of the system is an open software architecture that leverages cloud applications to import music or performing the route planning on a central server.
A contribution to efficiency is the active " Torque Vectoring "-Differenzial afford: A small electric motor in the transmission that can be operated as a motor and as a generator, the force ideally distributed on the two rear wheels. The improved stability when braking in curves can be recovered as without torque vectoring will use much more energy. At the same time the car is due to the favorable distribution of the driving and braking forces much more agile and secure, so the TU Munich.
Particular attention was paid in Visio.M also to the design of air and heating. Wherever heat generated is recovered them in order to use them when needed for the heating of the car can. In the air conditioner as well as in the seats so-called Peltier - elements are incorporated. This electro-thermal converter can both warm and cool. In very cold weather also fueled with ethanol burner for a range-neutral heating is available. The unit with a thermal heating power of about 4.5 kW shall in particular ensure the defrost the windshield.
And what is the future of the Visio.M? According to its makers of car to buy and run is cheaper than a comparable gasoline engine. But up to a production run, it is still a long way, because almost all the parts needed to be adapted to the special conditions of mass production . ( rh )