Coming Tech Breakthroughs

Electric Impulse Charging

Siemens VDO has released details on a new supercharging concept.

Electric impulse charging is accomplished by installing an electromagnetically-controlled valve in the intake manifold ahead of each cylinder. As the piston travels downward during the intake stroke of the combustion process, the valve is closed, creating a vacuum by sealing the cylinder. Just before the piston reverses direction to begin the compression stroke, the valve opens and the pressure drop that has been created draws air in at the speed of sound. The sharp intake of air bounces off the piston crown creating a counter-wave flowing back toward the top of the cylinder.

The valve seals again before the high-pressure wave can escape, resulting in an increased volume of air in the cylinder. As the valve switches from open to closed in a few milliseconds, this charging effect becomes immediately available within one power stroke.

With the electric impulse charger up to 30 percent increase of torque is possible at low rpm.

An additional benefit of employing electric impulse charging solution is the increased air pressure in the cylinder at the end of the combustion process improves the purging of exhaust gases. Far less residual gas is carried over into the intake and compression strokes of the next working cycle, which reduces the combustion chamber temperature and the tendency of the engine to knock.

Delphi Active Front Steer

Delphi Active Front Steer helps provides drivers with simplified city driving and parking by reducing the turning required at low speeds so that a hand-over-hand parking manoeuvres can be accomplished in as little as two thirds of a turn of the steering wheel. Delphi AFS smoothly transitions from a low-speed steering ratio to a high-speed steering ratio, providing a tighter, sportier feel for driving enjoyment and better control on the highway.

AFS accomplishes this by modifying the steering kinematics, or motion, of the vehicle in a manner similar to steer-by-wire. The system electronically influences the steering angle on the wheels enabling it to be greater or less than the driver’s steering wheel angle input. Turning into a parking spot or even manoeuvring a hairpin turn at moderate speeds can be accomplished with significantly fewer turns of the steering wheel. In essence, the system electronically turns the road wheels at a rate different than the rate the driver turns the steering wheel. Although some may think this could be intrusive or controlling, those that have experienced Delphi AFS suggest it helps make driving very easy and enjoyable with a very natural, transparent feel.

Unlike steer-by-wire, AFS maintains the mechanical link and uses the existing electrical architecture. This mechanical link helps ensure system safety. If the system is switched off or inadvertently loses power, Delphi AFS engineers incorporated a smooth default to the base steering ratio, apparently without disturbing or alarming the driver.

Delphi Active Front Steering can be integrated with controlled braking to provide a more effective vehicle system solution to stability control than brakes alone. AFS instantaneously delivers steering control; counter steering (ie opposite lock steering) the vehicle to bring it back on its intended course and if needed, blending in braking. In addition, this integration can help minimize vehicle-stopping distances on split and mixed frictional coefficient surfaces while maintaining directional stability.

Delphi Active Rear Steer

Not content with Active Front Steer, Delphi is also exploring the use of rear-wheel steering, a technology exploited to some degree by the Japanese in the mid-Eighties. However, the use of ‘active’ technologies adds potentially much more effectiveness to the systems. The demo car that the company is using is a Jaguar S-type.

The system is a low angle rear wheel steering system, which is specifically designed to offer European vehicle manufacturers an innovative, affordable solution for dynamic handling enhancement and active safety management on passenger vehicles.

Active Rear Steering can serve as a primary mechanism for enhancing the vehicle’s handling performance by using its highly tuneable software. Using dynamic control algorithms, the system provides the ability to specifically “dial in” desired handling characteristics. For instance, if the desired vehicle character is for a smoother ride via a softer suspension, Active Rear Steering can be used to help regain the desired handling using an algorithm that dynamically adjusts the rear wheel angle according to a vehicle behaviour model. The result is optimized handling performance and ride comfort.

 “Active Rear Steering separates the yaw and lateral dynamics of the vehicle,” explains Dr. Jean Botti, chief technologist, InnovationCenter, Delphi Dynamics & Propulsion Center. “This gives chassis design and tuning experts a new degree of freedom to control vehicle motion. When combined with the latest in advanced algorithms, Active Rear Steering allows our customers to achieve superior handling performance while also increasing dynamic safety through active rear steering.”

Delphi Active Rear Steering helps minimize over steer and under steer at all speeds, and on virtually all surfaces, even during normal driving, without slowing the vehicle. Emergency lane changes, or elk test manoeuvres, become more predictable, more manageable and less stressful when rear steering is added to the equation. Active Rear Steering can be integrated with controlled braking to provide a more effective vehicle system solution to stability control than brakes alone. Together these systems help deliver instantaneous rear steering control to bring a vehicle back on its intended course and blended braking as needed. This approach minimizes any slowing of the vehicle making the correction less intrusive to the driver. In addition, by allowing steering to maintain directional control and braking to slow the vehicle, this integration can help reduce vehicle-stopping distances on split and mixed frictional coefficient surfaces, such as snow and ice, in a stable, controlled manner.

“Active Rear Steering complements and expands the impact of brake-based stability control systems on vehicle dynamics by improving handling and yaw stability,” states Botti. “Bringing steering into the equation allows our customers to deliver the ultimate in active safety combined with a comfortable ride and superior handling.”

The system can also be configured with unique algorithms for improved handling and safety while towing a caravan or trailer.

DaimlerChrysler’s F 500 MIND Research Vehicle

F 500 Mind, DaimlerChrysler’s new research vehicle, is packed with innovations. “Mind” stands for intelligence and expresses the wide variety of innovations involved.

For the F 500 project the engineers at DaimlerChrysler developed a hybrid engine - a 4-litre, V8 diesel engine with 184kW and an electric motor with 50kW.  The potential fuel savings, as defined by the New European Driving Cycle (NEDC), are up to 20 percent higher than those associated with comparable conventional drives. About 10 percent can be attributed to the electric motor, while about six percent is the result of regeneration — in other words, the recovery of kinetic energy. This energy is converted into electricity when the brakes are applied and is stored in a new type of lithium-ion battery.

People who open the driver’s door in the F 500 Mind shouldn’t be alarmed when they see the steering wheel move to the side. In fact, the wheel actually slides 14 centimetres toward the vehicle’s middle to enable the driver to easily get in and get out. The movements are possible because the designers have abandoned the use of a continuous mechanical steering column. In its place, the F 500 has a drive-by-wire steering system in which the steering movements are transmitted as electronic commands, rather than via mechanical systems. The steering wheel and the steering gear are connected with each other only through cable and data.

To ensure that the connection is as secure as a mechanical one, all of the various components are at least duplicated and in some cases are even present fourfold to provide redundancy.

The F 500 also has a new type of mechatronic steering wheel that creates the normal mechanical resistance when the wheel is turned and prevents drivers from thinking that they are holding a non-working part in their hands. In this system, a mechanical spring and an electric motor produce resistance based on the driving situation and create the normal “steering sensation.” The steering gear is also new in the drive-by-wire concept. Because the F 500 has a driving mode with purely electrical propulsion, the design engineers replaced the normal hydraulic steering control element with an electric steering rack.

Electronics also have found a place in the floor: Instead of the conventional pedals that are depressed, the F 500 Mind has “force-sensitive” pedals. These are installed in a flat plate and contain pressure sensors that electronically transmit the driver’s commands to the throttle valve or braking system when he or she steps on the accelerator or the brakes.

The benefits of the system can be seen in the interior and front-end structure. In the footwell, the electronic pedals create about 12 centimetres of additional space — space that is normally taken up by the mechanical pedal travel. In an ergonomic payoff, the pedal unit can be adjusted to suit the driver’s leg length because the only thing that has to be moved is cable; there is no requirement to adjust mechanical parts.

One of the most exciting new innovations in the F 500 is “multivision.” This totally new type of multifunctional display installed in the dashboard provides the driver with an array of information such as vehicle speed, the driving mode and the navigation system’s road map upon request.

When the car begins to move, “multivision” appears as a high-quality instrument cluster with three round analog displays: the tachometer to the right, the speedometer in the middle and the display for the hybrid power plant to the left. Needles are illuminated and borders can be dimmed.

At the press of a button, the hybrid display becomes an operator menu with which the driver can do such things as set up the cruise control or a trip computer. Information from the assistance systems also can be displayed. The menu is operated using buttons inset in the steering wheel. In the same way, the driver can switch off the tachometer display and replace it with that of the navigation system.

And for trips made in twilight or at night, the F 500 has one other special feature that raises the safety level. “Instead of the navigation system,” a DaimlerChrysler spokesman says, “the video image of the night-vision system, which works in the infrared range, can be displayed. In this manner, a driver can considerably expand his or her field of vision in situations where visibility is poor.”

Using the night-vision system developed by DaimlerChrysler research, the driver can not only follow the course of the road, but also recognize obstacles, pedestrians and cyclists at a distance of 150 metres. Normal low-beam lighting, by contrast, is good for only 40 metres.

Passive night-vision systems recognize only those objects that give off warmth. However, that’s no problem for the system in the F 500, which has its own source of light. Two lasers integrated into the headlights send out invisible infrared light. An infrared video camera installed behind the windshield records the reflected image and supplies a black-and-white video for the “multivision” display.

For the driver’s seat, the F 500 offers the “cone of sound,” another piece of pace-setting technology. The system, which is based on ultrasonic technology, employs special speakers that transmit the sound at a very sharp angle.

In this way, they can provide information that is heard only by the driver. Such information includes traffic reports, telephone calls, warnings and language-operation dialogues for the navigation systems or radio. The benefits of this pinpoint speaker system are obvious - the other people in the car don’t have to listen to traffic reports or listen in on the driver’s telephone calls.

In the F 500, the driver’s seat is the only location outfitted with this innovative audio technology. However, the researchers plan to employ the knowledge they gain from their experience to further refine the system. When it becomes available for all seats at some point down the research road, each occupant will be able to select his or her own music without disturbing the other people in the car.