Siemens VDO starts eCorner development

Siemens VDO engineers are working on plans to integrate the drivetrain, steering, shock absorbers and brakes directly into the wheels of future cars. This concept, called eCorner, is the basis for the ecological "drive-by-wire" automobiles, which will become a common sight on roads in 15 years.

eCorner replaces the conventional wheel suspension with hydraulic shock absorbers, mechanical steering, hydraulic brakes and, above all, conventional internal combustion engines. For car owners, eCorner translates into improved fuel mileage, more safety and greater convenience. eCorner provides designers with all new freedom to create future cars with an electric drivetrain and electronic control.

The project is being seen as an attempt to find viable alternatives to large internal combustion engines, the future of which is being threatened by increasing crude oil prices. Using eCorner, Siemens VDO intends to replace traditional engine architecture will be replaced with electric wheel hub motors, which act directly on the wheels to accelerate the car.

The four independently operating wheel hub motors will offer extremely dynamic driving on the future highway. The possible elimination of the internal combustion engines burning petrol or diesel fuel will reduce emissions and will even satisfy the extremely strict laws being anticipated in the future.

AVOIDING ACCIDENTS

The Siemens VDO eCorner will make it possible to develop drive-by-wire vehicles on which the drivetrain, steering and brakes provide common support for the driver in critical driving situations, thus helping to avoid potential accidents.

Although Siemens VDO will continue to invest in optimisation of conventional internal combustion engines in an effort to completely exhaust their potential, the perspectives for the future are even more important. "Hybrid drives are only an intermediate step along the path to future propulsion solutions. We consider the electric motor to be the actual long-term drive solution for fulfilling even the most stringent emission laws of the future", said Dr. Klaus Egger, group vice president of Siemens VDO Automotive.

In the future, car wheels will take on a different appearance than today's familiar steel or alloy wheels. With eCorner, a tyre containing a sensor (tyre guard) for monitoring the inflation pressure will be in contact with the road. Even the wheels' suspension of the future will significantly differ from today's design. Within eCorner, electric motors will take over the task of ensuring contact between wheel and road. With this new suspension, hydraulic steering can be eliminated, giving automakers new degrees of freedom.

Also, each individual wheel can be moved to its own specific steering angle. When the speed is reduced, the wheel hub motors would act as auxiliary brakes using a generator effect. The energy reclaimed in this manner would be used to charge the vehicle battery. Finally, in addition to the generator brakes, the electronic wedge brakes (EWB) would decelerate each wheel separately with maximum precision and enormous braking power to match the need of the driving situation.

CONSUMER BENEFITS

The change-over from internal combustion engines to eCorner wheel hub motor concept will be enhanced by various aspects, for drivers as well as for automobile manufacturers, such as energy efficiency and the associated emissions. Under optimum conditions, a future full hybrid system utilises approximately 85 percent of the theoretically available energy.

Energy utilisation in today’s petrol and diesel engines is less than 50 percent. Wheel hub motors are projected to use up to 96 percent of the provided electrical energy for vehicle propulsion. This will make it much easier for automakers to satisfy emission regulations and while simultaneously offering extremely dynamic vehicles with excellent fuel economy.

The integration of various vehicle components into the wheels would allow further modularisation of future cars: Vehicle manufacturers will only require different drive wheel layouts for equipping highly differing vehicle concepts. eCorner has the potential to allow a completely new vehicle design, when the large central engine with all its accessory parts and transmission are eliminated. Driver assistance systems using eCorner for support will offer drivers entirely new possibilities.