Electronic Wedge Brakes Signal Future Electric Cars

Electronic Wedge Brakes, scheduled to appear on a German production car, probably in 2008, are the first part of a multi part concept called “eCorner” by Siemens VDO. Electronic Wedge Brakes or EWB, eliminate the hydraulic system used to power the brake pads in current automotive systems and substitute 12 volt electric motors that move rollers and a wedge shaped interface. The EWBs are considerably more efficient than today’s brakes, requiring only a tenth of the energy used in hydraulic systems for an equivalent braking force. Although the EWB system is impressive, the total eCorner concept, of which the Electronic Wedge Brake is only a part, signals a seismic shift in automotive technology; it may well be the beginning of the end of the internal combustion engine as the primary motivator in cars, trucks and most motor driven vehicles.

The eCorner concept combines the drivetrain, steering, shock absorbers and brakes directly into the wheels of future cars, replacing the hydraulic shock absorbers, mechanical steering, hydraulic brakes and even the internal combustion engines. It’s a huge step but the technology is not far off.

With the introduction of automotive computer controls, many earlier systems using mechanical or electromechanical feedback loops are now able to function in ways undreamed of before the computer was installed. Pollution control systems, fuel injection, ignition timing, anti-lock braking systems, traction control systems and many more now perform tasks perfectly where the old systems worked poorly or were not even possible.

As increased computer intervention in the overall operation of cars takes place, combined with the dramatic improvement in electric motors, batteries and other electrical systems we are already seeing, the benefits of moving in this direction will become clear. Sensors will be able to determine road conditions and react in microseconds, long before the driver even knows a correction is necessary. Dramatic redesigns of cars will be possible when the engine compartment and the space occupied by the current driveline will no longer be necessary and passenger and load compartments can be situated where they makes the most sense.

Eliminating the internal combustion engine from cars will reduce vehicle pollution to almost zero and put the control of pollution back at the power generating station which may be much easier with a larger fixed system and with the use of a variety of power generating technologies.

The electric car, made possible by eCorner, will also dramatically reduce reliance on oil supplies from uncertain sources caused by problems both geological and political. It’s a winner from almost every angle.

The potential downside is the mental shift necessary to get around the loss of the well known and century old internal combustion technology which will not phase out for a long time under any circumstances, anyway, but the upsides are many.

It’s one more reason for anyone contemplating a career in the automotive field to get very comfortable with volts, ohms and amps along with compression ratios and ignition timing. It’s also a sign that the days of the low tech mechanic, if they were not over already, are certainly much closer to being over now.

Siemens VDO press release follows:

Car motors will disappear – into the wheels: 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.

There are enormous requirements placed on tomorrow’s vehicles. In the future, it will be vital to be as thrifty as possible with every drop of crude oil, making it necessary to find alternatives to large conventional internal combustion engines. As a result, Siemens VDO projects the traditional engine architecture will be replaced by 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 gasoline or diesel fuel will reduce emissions and will even satisfy the extremely strict laws being anticipated in the future. 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.

The intermediate hybrid motors step
Although Siemens VDO will continue to invest in optimization 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”, stated Dr. Klaus Egger, Group Vice President of Siemens VDO Automotive.

eCorner combines drivetrain, steering, shock absorbers and brakes
In the future, car wheels will take on a different appearance than today’s familiar steel or mag wheels. With eCorner, a tire containing a sensor (Tire 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. While complex mechanical wheel suspension systems with oil-pressure spring elements ensure a comfortable ride for the passengers and permanent, reliable contact with the road, electronic circuits will play an increasingly significant role in the future. 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. In the future, each individual wheel can be moved to its own specific steering angle. When the speed is reduced, the wheel hub motors act as auxiliary brakes using a generator effect. The energy reclaimed in this manner can be used to charge the vehicle battery. Finally, in addition to the generator brakes, the electronic wedge brakes (EWB) can decelerate each wheel separately with maximum precision and enormous braking power to match the need of the driving situation.

eCorner’s drivers and automobile manufacturers advantages
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 utilizes approximately 85 percent of the theoretically available energy. Today’s gasoline and diesel engines is even 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 automobile manufacturers to satisfy emission regulations and while simultaneously offering extremely dynamic vehicles with excellent fuel economy. Integration of various vehicle components into the wheels allows further modularization of future cars: Vehicle manufacturers only will require different drive wheel layouts for equipping highly differing vehicle concepts. Moreover, 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. Cars that can virtually park sideways using pivoting wheels or electronic steering aids and controlled acceleration of individual wheels for better vehicle stabilization in hazardous situations. Finally the costs for car owners will also be reduced: Fewer components and elimination of the hydraulic systems will reduce wear and service complexity.

On the way to eCorner
Siemens VDO believes the electronic wedge brake’s start of mass production is an important milestone on the way to eCorner realization. The first car on public roads at the end of this decade with the Electronic Wedge Brake (EWB) will demonstrate the advantages of a completely electric brake system, opening the door for other elements to be integrated into the wheel. The greatest intermediate step toward eCorner will be the integrated corner module. During the next decade, this system will integrate all systems into the wheel with the exception of electronic shock absorbers and electronic steering. The combustion engine won’t have to disappear completely for the time being: it will be able to provide the necessary electrical power for flexible long-distance vehicles.

Link: Siemens VDO
Link: Autoweek