BMW is leading a consortium of German firms focused on creating a lightweight frame scalable to production electric vehicles. The Visio.M consortium was recently granted $15 million through 2015 from Germany’s Federal Ministry of Education and Research. This group will develop an EV prototype weighing less than 1,000 pounds as part of the ministry’s IKT 2020 program. The resulting prototype will fall into the IKT 2020 theme of “Key Technologies of Electromobility.” BMW is working with major partners like TUM, the Federal Highway Research Institute, Siemens AG and Hyve AG to develop this concept.
The foundation of the Visio.M concept is the MUTE research EV developed by students and researchers at TUM. The MUTE can achieve a per-charge range of 62 miles with a top speed of 75 miles per hour. These metrics allow the typical German driver complete daily tasks without contracting range anxiety. The TUM design team built a 15 kW electric drive system that is efficient enough to keep up with traditional compact cars. Consortium members will start with the MUTE concept but tweak every component to drive down curb weight while achieving better performance.
BMW and partners will construct a monocoque body with lightweight cockpit for the finalized concept. The vehicle frame would borrow heavily from Formula One designs to ensure vehicle stability as well as safety. A monocoque body made from composites reduces the effects of crash impacts while holding the curb weight to 882 pounds without the drive system. The cockpit designed by Visio.M uses carbon fiber-reinforced plastic (CFRP) for a lightweight but comfortable ride. BMW, Daimler and other industrial partners will assess whether the final product could be replicated in a production compact EV.
A lightweight EV frame can be offset by a motor, battery pack and components that pay no mind to curb weight. The drive system under development by Visio.M would achieve ample driving range from relatively low output by cutting down weight. The electric motor would be operated using lightweight gears and hollow shafts that could drop system weight by 15%. Another facet of drive train design that should come under the microscope is the heft of the battery pack, which is a common problem for EV designers. Reconsideration of the EV drive system might be the most difficult aspect of the consortium’s work due to the balance between costs, performance and weight.
TUM has already undertaken testing on the MUTE EV at a race track in Munich. This test demonstrated the effectiveness of the Electronic Stability Program, essentially an advanced version of anti-lock brakes. A positive result from Visio.M would be important for the green vehicle market niche throughout Europe. Automakers and consumers throughout the world are concerned with the safety features in EVs as well as high upfront costs. BMW, TUM and other partners in Visio.M are attempting to reduce costs significantly by cutting away extraneous elements. A lightweight but durable frame and simpler drive system cure some perceptions about EVs that stifle their market penetration.