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The new 7-Series BMW is fitted with this ZF six-speed automatic transmission. All six ratios are used in both the drive an manual modes. In the latter case, the selection is via two buttons on the steering wheel spokes. There is also sport mode that allows the engine to re higher, and locks the sixth ratio out.

ere's nothing like a bit of pressure to bring out the best in people and companies. In the automotive world, we find that legislative bodies in many countries are applying an ever-tightening noose around the corporate needs of the major manufacturers to produce cars that are safer to drive, safer to be in, and more economical to operate, even if they cost an arm and a leg to buy. In addition, they're also competing amongst themselves to be the first to produce another breakthrough in the battle for the customer. Even the smallest advance is hailed as an industry first, and it doesn't seem to matter if history proves them wrong.

On the positive side, one has to admit that the results have been spectacular, and the end is not yet in sight, if the recent Frankfurt motor show is anything to go by. There were a number of new developments on show as well as some refinements of previously shown components.

The latest refined versions of the integrated starter alternator damper (ISAD) must be high on the list of promising ideas, because this device is said to make a difference of between 12 and 20 per cent in overall fuel consumption. This is no an idle boast, because the theoretical advantages are easy to understand, but the results do depend how the system is integrated with the rest of the vehicle, and how it is used. Most of these units are fitted in the space normally taken by the flywheel, and they also replace the starter and solenoid unit, the alternator and its drive, and, for certain types of engine, even the vibration damper on the crankshaft.

This sketch shows the principle behind Contitech's SWT sensor system, described below. Note that the time difference between the two waves depends on the amount of distortion between the rubber close to the tread and the rubber near the rim of the wheel, which is why it measures the torque. In addition, the amplitude is proportional to the amount of distortion caused by a lateral force: while the frequency, ie, the number of cycles per second, depends on the wheel speed.

Visteon is also experimenting with belt-driven and flywheel-replacing starter/alternator units. It says that at least one car manufacturer will introduce a Visteon unit in 2003, with more to follow. Volvo appears to have designed its ISAD in-house, but has opted to call it an ISG (Integrated Starter Generator).
Braking systems are in a state of flux, with full electric brakes being the ultimate aim, but legal and reliability concerns are keeping these units out of production. Meanwhile, the new Mercedes-Benz SL roadster is fitted with an electro-hydraulic brake system (EHB). In this system the brake pedal is linked to an electronic actuation unit, incorporating a pedal feel simulator and sensors for monitoring the drivers' actions. This unit sends signals to the combined ABS-EHB controller, which sends brake fluid to the wheel cylinders, and the pressure changes do the actual braking, just as in normal ABS system. This eliminates the normal master cylinder and the brake servo. The claimed advantages are shorter stopping distances, optimised braking behaviour and pedal feel, no pedal vibration during ABS operation and improved packaging.

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Some people claim that a magnet surrounding the petrol pipe improves fuel consumption. Contitech also believes in magnets, but they've put their magnets around the flywheel, to create an ISAD that is claimed to achieve a fuel saving of up to 20 per cent.

his will eventually be replaced by an electro mechanical brake system (EMB), which does away with the hydraulic components by linking the control unit electronically to a wheel brake module consisting of a powerful but compact electric actuator. This will eliminate the use of brake fluid, make parking brakes more powerful and reliable, and be easier to integrate into all the other electronic functions that control handling and traction.

Contitech is working on what it calls the '30-metre car' and is planning to show a prototype by the end of this year. This is a car that can stop dead from 100kmph in 30 metres, instead of the more normal 40 to 45 metres that a quality car, fitted with ABS brakes, will require. Such a feat amounts to an average deceleration of just over 1.3g, which implies a frictional coefficient of the same value, amd must rely heavily on a rack-and-pinion effect between the tyres and the road. This will require an optimisation of the braking system, tyres, mass distribution, damping and spring rates. This car will be fitted with Conti's ESS (Electronic Suspension System), described later, which uses air springs, but one of the most exciting new ideas that will help to achieve this goal is the SWT (SideWall Torsion) sensor system. This is a totally new way of monitoring what the tyres are doing, so that the resulting ABS, traction control and ESP functions will be more effective and come into action sooner. Each tyre has iron particles embedded into its sidewalls, so that a magnetic sensor fitted to the suspension units will pick up the tyre deflection, from which the speed, lateral force and torsion can be calculated. This system can also detect brake malfunction, damage to the tyres and changes in pressure.
Blowouts, especially on vehicles with a raised centre of mass, have been in the news recently, and there is speculation that tyre pressure monitors will soon become mandatory. A number of such units are in production already, but they either have to be fitted on the wheel, once the tyre has been removed, or they replace the normal valve. The Contitech solution is particularly neat, because the tyre pressure detection unit monitors the signals sent by the ABS wheel sensors to the ECU, or the signals sent from the SWT, once this is in production. This system works on the principle that, if a tyre is starting to lose pressure, the effective diameter will decrease, leading to an increase in wheel speed.

Another interesting brake development is the eBrake, developed by eStop. This company is a spin-off of DLR, the German Aerospace Centre. It showed a novel disc brake that uses a wedge instead of a piston to apply pressure to the disc. This system uses the vehicles kinetic energy to supply the braking effort, reducing the energy input from other sources by 90 per cent, but needing careful electronic control to prevent over-braking or wheel locking.

Air spring suspension units are not new, because they're very common on luxury cars from time to time. Contitech's ESS units are controlled by a processor that can alter the pressure electronically to change the damping spring characteristics and even the height of the car body above the ground, to fit in with changes in the driving and load conditions. The control unit is linked to the ESP control, for increased effectiveness, and the claims are that it reduces rocking, nodding and fluctuation of the wheel load.

ZF employees an electrohydraulic control unit on manual gearbox fitted to certain 3-Series BMW models to achieve a sequential shift.

Many modern automatic gearboxes waste very little energy, and change gear seamlessly. The latest fashion is to install six-speed automatics, and the new ZF myTronic unit will be fitted to the latest 7-Series BMW. This is said to be 13 per cent lighter, use five to seven per cent less fuel and improve acceleration by one to five per cent, compared with ZF's previous five-speed design. It can transmit up to 600Nm on torque, and features an adaptive shift strategy made possible by a sophisticated electro-hydraulic control that constantly evaluates the signals from various sensors so that it can respond to driving style and operating conditions. It also disconnects the torque converter at idling to save fuel, and has the very wide ration spread of over six (the lowest ratio divided by the highest).

Aisin and Jatco, both from Japan, also have six-speed automatics ready. Some of the Lancia models, as well as the Alfa Romeo 156, are available with Aisin's Q-system, which is an automatic transmission with a normal H-shaped gate when operated in manual mode. This company also showed the Navi-Matic system. This is an automatic transmission linked to a CD-driven navigation map that selects the appropriate gear for the terrain to be traversed, just as the vehicle gets there. The technology is mind-boggling, but many people will feel that this is perhaps going a bit too far.

These modern wonders are being challenged by CVT's (continuously variable transmission) and electronically controlled manual gearboxes. ZF has ben in the forefront of CVT development, and its new version is available on the new Mini. The same company is involved in a joint venture with Ford to build CVTs in the USA for some Ford products in 2003. LuK, the clutch and drivetrain specialist, has a very interesting CVT, described that is already in production for the new Audi A6. In Japan, Aisin and Jatco units have been fitted to small production runs of various Japanese models since the late '90s when a small Subaru car used a CVT.

All of these units incorporate steel belts and variable-width pulleys, often with a torque converter, but Jatco's most interesting exhibit was a toroidal CVT. This uses tapered rollers that tilt while remaining in contact with specially shaped pulleys to transmit the torque, which can be as high as 370Nm in the case of the largest unit.
ZF has also developed an electro-hydraulic transmission with help from Magneti Marelli, to enable a manual gearbox to change sequentially, like a GP racing car's. This unit is already in production for certain BMW 3-Series models.

The German Hella company showed a very interesting night vision system. It incorporates an infra-red camera that projects an image in a display on the windscreen. This system can sense the heat from living bodies in the same way that vipers can detect mice in the dark, enabling the easy spotting of humans and animals in complete darkness.

Finally, diesel engines are also benefiting from further development. Delphi has released details of its APC (Accelerator Pilot Control) closed loop system, which 'listens' to the combustion and sends a signal to the ECU, which is able to adjust the injection timing to ensure that the system is always correctly calibrated to maximum performance and minimum noise. The effect is similar to that achieved by fitting a knock sensor to petrol engines. Peugeot and Bosch are also experimenting with piezo-electric fuel injectors employing a ceramic that expands when a current is sent through it, and can react up to four times faster than elecctro-magnetic units, allowing more advanced control of the combustion process. These injectors will be in production within a year or two.