The European Union is set to lift its ban on steer-by-wire cars in a move that could soon bring vehicles that are totally controlled by electronics to the UK.
This represents a major opportunity for the automotive industry which has been developing the technology to improve handling and safety.
Manufacturers – including General Motors, Mercedes and Lotus – have been pushing for a change in the law to allow electronically operated steer-by-wire to replace conventional steering.
But this is currently banned under the European construction and use Regulation ECE 79 which calls for a mechanical link between the steering wheel and the road wheels.A spokesman for the Vehicle Certification Agency, the UK’s national approval authority for new road vehicles, said that proposals have been drawn up to draft an amendment to the regulation.
A European Commission spokesman said that Regulation 79 will be discussed again at the next meeting of a working group on 16-18 September. ‘Before further amendments to Regulation 79 can come into force EC agreement will be required,’ he said.
Earlier this month General Motors unveiled its Hy-wire concept, a driveable vehicle prototype with fuel cell power and all controls operated via a single joystick unit known as an X-drive.
It follows Mercedes Benz’s F-400 Carving research car, unveiled last year, which also used steer-by-wire but retained a conventional steering wheel. Mercedes is now researching the possibility of integrating a joystick-based controller.
Though motorists might initially balk at being connected to the wheels only by electronics, engineers see many advantages.
Nigel White, executive engineer for vehicle dynamics at Lotus Engineering, the consultancy arm of the Lotus group, said: ‘We see enormous benefits in steer-by-wire. Removing the steering column removes the dangerous crash characteristic of having a steel rod facing the driver’s chest.’ Lotus has been investigating a fully active steering system since 1998.
Replacing a mechanical link with electronics allows steering effort and response to be changed electronically to make the steering light when parking, but retaining steering feel at high speed. The Mercedes F-400 system uses force feedback to make it ‘weight up’ at speed so it feels like a normal car.
In an emergency a steer-by-wire system could be programmed to counteract a skid automatically, producing faster reactions than most drivers.
Removing the need to connect the engine bay with the cabin unlocks a great deal of freedom in packaging the vehicle systems. Separating the steering mechanism from the engine compartment could also allow the engine to be mounted lower. This could help solve a potential conflict between styling and packaging caused by forthcoming regulations on pedestrian protection.
Meeting these regulations is expected to require more empty space between the bonnet and hard components underneath, resulting in a higher bonnet line.
Previous resistance to the system has been based upon fears that something as simple as an electrical failure might cause the driver to lose control of the vehicle.Filippo Zingariello, vice-president of SKF’s Drive-By-Wire Business Unit, which developed Hy-wire, said that making an electronic system failsafe was not a problem. ‘We have 15 years’ experience with fly-by-wire with Airbus. We would take the same approach, using criticality analysis to establish the correct level of redundancy.’ In other words, critical parts of the system are duplicated, if necessary several times.With permission to supply the product in the pipeline, General Motors is directing its efforts towards ‘educating’ the public, media and law makers to the advantages of the technology.
The company is keen to press ahead and market the system within Europe, and a spokesman confirmed there would undoubtedly be a more concerted lobbying effort in the future. ‘We are in the initial stages and there will be a gradual ramp-up,’ he said.
‘All the car manufacturers are trying to convince the EU to modify this regulation, but it takes many steps.’ said a DaimlerChrysler spokesman, whose company offers its Sensotronic brake-by-wire system on its SL roadster. ‘We have to prove that steer-by-wire is as reliable as a mechanical system. All the countries have to agree and technical experts and lawyers have to be convinced,’ he said.
It may not be enough to remove adverse regulations. A positive framework of standards may be needed, said Mark Fowkes of the automotive research group MIRA.
‘For driver-assistance systems such as drive-by-wire there is no law or standards to verify designs against. There is not enough of a legislative framework for manufacturers to say: ‘If we design this and if it meets the legal requirements we can sell it.’ Regulations may be needed to create the environment for manufacturers to go ahead.’