Electromobility, efficient and safe: Visio.M consortium presents new electric car

October 20, 2014, Technical University Munich
Visio.M: lightweight, highly efficient and safe, with timeless, modern and functional design. 15 kW are enough to reach a top speed of 120 km/h (75 mph). Credit: Florian Lehmann / TUM

An attractive electric vehicle at an affordable price that provides safety and comfort combined with a reasonable driving range: that was the goal of the Visio.M project. The participating researchers at the Technische Universitaet Muenchen who put together the car in collaboration with specialists from industry are now unveiling it to the public.

More and more people are considering the purchase of an electric car. Whenever possible, it should run on renewably generated electricity. They want to conserve fossil resources and make a contribution to the environment – while playing the role of pioneers in an unstoppable trend over the next few years.

In the Visio.M collaborative project researchers at TU München, together with experts from industry have been exploring what an all-round, sporty, low-price and safe electric car might look like. The result of the undertaking, which has been funded by the German Federal Ministry of Education and Research for two and a half years to the tune of 7.1 million euro is a very small vehicle that sets new standards regarding efficiency and safety. The researchers will unveil their car to the public at the eCarTec from 21st to 23rd October 2014.

Speedy lightweight

The Visio.M has a driving range of around 160 kilometers and space for two people and luggage. With only 15 kilowatts of engine power, the car can achieve a top speed of 120 km/h (75 mph). Its design is sporty and self-confident. The features fulfill all significant requirements of a normal car, from infotainment and navigation assistance to climatization.

The electric motor draws its energy form a 13.5 kWh lithium-ion battery comprising consumer cells and is mounted behind the seats. The battery weighs almost 85 kg and can be charged from a 230 V socket in only three to four hours. The total cost of ownership, including initial investment and operating costs, will be lower than that of a comparable combustion engine car.

Decisive for the great energy efficiency of the Visio.M is its light weight. The passenger compartment is made of carbon fiber reinforced plastic with aluminum in the front and rear sections, as well as the roof frame. All windows are made of polycarbonate. This material weighs only half as much as glass but, thanks to a special coating, is equally resistant to scratches and weathering. The researchers also saved weight in chassis, steering and transmission by using special light-weight constructions. Without the battery, the Visio.M weighs only 450 kilograms.

"Light weight is essential for an electric vehicle," says Prof. Markus Lienkamp, Chair of the TUM Institute of Automotive Technology, "because more weight requires more battery performance for the same range and thus generates higher costs. More weight also means poorer driving dynamics at the same performance. But we want a car that is affordable and fun to drive."

Safety first

An all-round, mass market car must guarantee effective passenger safety. Especially in collisions with heavier vehicles, small cars must provide a safety zone in spite of their small dimensions. The passenger compartment of the Visio.M consists of an innovative, multi-section monocoque made of carbon fiber reinforced plastic combined with ultra light sandwich materials imparting it with exceptional rigidity.

In addition, the engineers have developed a safety concept that includes a systematic anticipatory analysis of the surrounding traffic. The 360° monitoring of the immediate vehicle vicinity via radar and camera sensors makes it possible to detect critical driving situations early on. This information is not used for driver assistance or warnings. When the car detects an imminent unavoidable collision it activates the integrated passenger protection systems just before the actual crash takes place.

Novel structural airbags are mounted in the bumpers and doors. Fractions of a second before a crash a gas generator fills these pressure tubes, which then act as additional absorption elements.

Adaptive seat-belt tensioners and force limiting systems reduce the forces acting on the passengers. A two-point belt combines with the normal safety belt holds the passengers firmly in their seats. When the system detects an imminent side collision, the passenger on the crash side is pulled toward the inside of the vehicle together with the seat just before the collision, thereby moving away from the immediate danger zone. The pre-acceleration of the passenger reduces the crash forces acting on the passenger and increases the effectivity of the side airbag. A potential collision between the driver and passenger is prevented by an interaction airbag mounted between the seats.

Ergonomic design

In contrast to conventional cars in which the heel of the driver is defined as a fixed point for the adjustment functions, in the Visio.M the driver's eyes serve as a fixed point. This allowed the researchers to position the safety systems and the traffic perspective optimally. The driver's seat must only be adjusted vertically. In exchange the pedals are adjustable.

Control elements for the radio, air conditioning and navigation assistance are accessible via a central touch display, which is also adjustable. The human-machine interaction consists solely of swiping gestures that can be made on the entire display. The driver does not need to hit any buttons and a quick glance is sufficient for visual orientation.

At the core of the system is an open software architecture that can be extended at any time with additional elements. This opens the door to things like accessing home music collections via cloud applications or performing compute-intensive applications like energy-efficient route planning based on current weather and traffic conditions from a central server. All kinds of premium services can be implemented in this way. In the future, for example, a rental car might be delivered to a customer's door via remote control. This concept has already been implemented experimentally.

Large driving range

Many aspects must be brought together before the vehicle can achieve a large driving range in spite of its relatively small battery. These include light weight, low aerodynamic drag, an efficient drive train, minimal rolling friction and energy-saving air conditioning.

The researchers have optimized these parameters in the context of the Visio.M project. Thus the 1.55 m wide and 1.31 m high two-seater now has excellent aerodynamics. In addition to low vehicle weight, the combination of low coefficient of drag of only 0.24, small frontal area of 1.69 square meters and tires optimized for low rolling resistance (115/70 R 16) further reduce the energy consumption.

The active "torque vectoring" differential also contributes to overall efficiency: A small electric machine in the gearbox that can be operated as an electric motor or as an electric generator distributes the force optimally between the two back wheels. Because of the improved stability while braking in curves, significantly more energy can be recovered than without torque vectoring. At the same time the car becomes much more agile and safe, because of the optimal distribution of drive ad braking forces.

Energy-saving air conditioning

Special attention was paid in the Visio.M to the design of the air-conditioning and heating systems. Wherever warmth is generated, it is recovered for heating the car when required. So-called Peltier elements are integrated into both the cooling aggregate and seats. These electrothermal converters can heat as well as cool. This allows environmentally friendly operation without the use of coolant fluids.

During very cold weather an ethanol-based heater can be switched on for driving range independent heating. The aggregate with a thermal performance of approx. 4.5 kW is especially useful for deicing the windscreen. An intelligent controller finds the optimal solution for energy efficient and comfortable operation of the air-conditioning system.

Electromobility for the masses

During the development of the Visio.M, the various systems were subject to numerous trials to test their functionality, safety and reliability. The result is an electric car that should find great interest, especially in industry. Prof. Markus Lienkamp is optimistic: "With the Visio.M we have demonstrated that it is possible to build a very light and at the same time safe with overall costs that we expect to be lower than those of comparable combustion-engine cars. But it is still a long way to serial production because almost all components must be adapted to the manufacturing conditions of large series."

Explore further: Visio.M consortium presents safety package for compact electric vehicles

More information: www.visiom-automobile.de/

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9 comments

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ScottyB
not rated yet Oct 21, 2014
This car is a backwards step. Look at what Tesla are doing, or the mainstream car manufactures, all have better range, passenger capacity and style than this
antialias_physorg
not rated yet Oct 21, 2014
The battery weighs almost 85 kg and can be charged from a 230 V socket in only three to four hours

Which would draw the full 16 amps that most households are currently rated for. It's probably wiser to extend charge times a tiny bit in order to not blow a fuse. I wonder what the range is at 100-120km/h constant speed - which would be the speed for the largest part of commutes.

The driver's seat must only be adjusted vertically. In exchange the pedals are adjustable.

Clever. Same way the formula 1 does it.

Look at what Tesla are doing, or the mainstream car manufactures, all have better range, passenger capacity and style than this

And it costs a hell of a lot more. What good is an EV going to do if the masses can't afford it?
Eikka
5 / 5 (1) Oct 21, 2014
This car is a backwards step. Look at what Tesla are doing, or the mainstream car manufactures, all have better range, passenger capacity and style than this


On the contrary. Tesla is making expensive cars to rich people, and cannot produce an affordable car for the rest because they're trying to achieve everything a regular car does. The others are trying a compromize and building normal cars with electric engines, but only achieve bad compromizes that are still too expensive and can't deliver the rance they promise because they're too big and the techology isn't there yet.

This concept on the other hand is the Fiat 500 or Citroen 2CV of electric cars instead of a Maybach or Rolls Royce. Something that people can actually buy, that might actually work.

The numbers check out nicely with only 12 HP required to drive the car 65 mph on the highway, even with headwind in the calculations, so they aren't exaggerating the range - which is a nice surprise.
Eikka
5 / 5 (1) Oct 21, 2014
Which would draw the full 16 amps that most households are currently rated for.


Typical households are rated for much more than 16 amps. It's just that you can't get more than that out of a single ordinary appliances socket per code.

A special 3-phase socket can be installed that provides 3x16 A if desired.

The low energy consumpition means that this car can recharge much more miles overnight than the bigger electric cars, so it's less limited about where you charge it.
Eikka
5 / 5 (1) Oct 21, 2014
The obvious problem of the big electric cars like Tesla Model S is that they consume more electricity than can be reasonably supplied. In the lack of a dedicated recharging infrastructure, that is an important consideration.

The same 220 V 16 Amp socket can recharge a Tesla Model S to the tune of 100 km over 8 hours, whereas this car can drive 300 km with the same downtime - albeit you have to drive it in two passes.

With this car, even regular engine heater sockets in garages and residential parking lots can provide you with enough charging to get you back home, whereas with a Tesla you're stuck for the whole evening.
antialias_physorg
5 / 5 (1) Oct 21, 2014
A special 3-phase socket can be installed that provides 3x16 A if desired.

Yes, but that would take some rebuilding. With the regular sockets I could just drop a line down from my balcony (as my parking space is conveniently right below it). It's unfortunate that this car (or ones like it) are a few years off. I'm currently looking to buy a new car, and I very much would like an EV. But there's yet nothing sensible (or affordable) on the market.

if it could recharge off of a 3 phase socket (or similar) at dedicated filling stations then an hour wait time would not be too onerous for the occasional 250km trip or so.

even regular engine heater sockets in garages and residential parking lots can provide you with enough charging to get you back home,

Company I'm (proxy) working for is one of the biggest in the energy sector worldwide. They just built a new office building for us with hundreds of parking spaces. Not a single EV recharge station. Go figure.
gkam
1 / 5 (1) Oct 21, 2014
I love it. We proved electric vehicles work in the 1980's for the Postal Department, and had lined up the transition to electric vehicles, until one of Reagan's appointments changed the plan. He was fired for being a crook, but it still put us back decades.

I consulted to power companies nationwide, and get a real kick out of seeing the California-hating Southerners in utilities driving Teslas made in California by former hippies.
Eikka
5 / 5 (1) Oct 21, 2014
We proved electric vehicles work in the 1980's for the Postal Department


Curiously enough, they tried the same thing in Finland and Sweden in the 80's and 90's with the Finnish post office and some private delivery company.

http://en.wikiped...Vehicles

As far as I can figure it out, they decommissioned every single one because they were more expensive to operate per mile than regular cars, and the heavy weight of their batteries reduced the amount of cargo or mail they could carry.

Today, the company is apparently making electric zambonis and golf carts.
Eikka
5 / 5 (1) Oct 21, 2014
With the regular sockets I could just drop a line down from my balcony (as my parking space is conveniently right below it).


Electric vehicles are really not suitable for apartment dwellers, which is ironic because they're the most useful in the city.

Even if you can drop an extension cord from your balcony, it's not exaclty suitable or safe for 16 amps because the long cord restricts the current flow enough that the breakers may not trip instantly or at all if there's a short. Your interior sockets are wired and fused with the assumption that any device connected is within a couple meters, not 25 meters down the wall and across the yard.

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