Drive-by-wire closer than you think

Fly-by-wire control systems are well established in the aerospace industry. Now participants in one IST project, PEIT, have ambitious plans to introduce the same capabilities to road vehicles. The objective? Potentially reducing road accidents within the EU by half!

“We know that 98 per cent of vehicle accidents are caused by driver error,” says project leader Ansgar Maisch of DaimlerChrysler, “so giving the driver a virtual assistant able to correct mistakes has the potential to reduce the number of vehicle accidents by half.” Such a system could be capable of detecting obstacles in the road or too high a speed on a curve in the road, and take action to control the vehicle, he says.

Taking over the driving

Research in the PEIT project, which is due for completion in August 2004, has focused on an in-vehicle Electronic Control Unit (ECU) that is capable of taking over control from the driver should various sensors indicate a dangerous situation. Such situations could include a heavy truck starting to veer out of its lane if the driver falls asleep for example, or getting dangerously close to the vehicle in front.

The ECU in question is derived from the aircraft industry. In fact it is the unit used in the Airbus A380 aircraft, a dual-duplex architecture that has four separate processors carrying out the same instructions. The result is a highly fail-safe system.

The theory behind the system is based on the idea of there being only one single ’motion vector’ that is correct for any given road and vehicle-position situation. A human driver can attempt any number of motion vectors at any time, i.e. he/she could steer the car in the wrong direction. But only one motion vector is correct, and therefore safe, for a given situation.

Range of vehicle types

PEIT is capable of integrating inputs from any number of vehicle systems, including data from external sources as well as in-vehicle information. It is then able to act on all of the controls that are normally operated directly by the driver, including the engine, gearbox, braking and steering. “So you can have drive-by-wire, steer-by-wire, brake-by-wire and even energy management,” says Maisch.

The PEIT platform can be fitted to vehicles of all types and sizes. The project participants already have two working demonstrators, a large truck and a Smart city car, to show the range of vehicle types covered.

The participants believe that PEIT will contribute significantly to increased traffic safety, to improved traffic flow and, last not least, to the comfort of drivers. By developing an intelligent system for driver warning and accident prevention, as well as support for automated driving functions and emergency reactions, PEIT contributes directly to the IST programme’s aim to address the major socio-economic problems facing Europe specifically through systems and services for the citizen.

Future? The virtual driver

Maisch emphasises that the full potential of the virtual driver system (of which PEIT is a key part) will only be reached when the system is fully predictive. In other words the system would not just react to driver error after he or she has made a mistake, but will actually be able to predict from a variety of inputs (e.g. GPS, weather and traffic conditions) the safest vehicle position, direction and speed for the road conditions at that moment. Thus not only would it help adjust engine power and braking force for maximum vehicle stability when for example a skid starts (as current systems do), but could actually take over control of the vehicle to prevent the driver error in the first place. In effect, the virtual driver!

PEIT has already led to a follow-up initiative, called SPARC, which is developing the command level of the system. SPARC will merge the data from all the various driver and vehicle systems to generate the one correct motion vector, which will then be fed to the PEIT control platform.

Contact:
Dr Ansgar Maisch
DaimlerChrysler AG
Mercedes Str. 132
D-70546 Stuttgart
Germany
Tel: +49-711-1752289
Fax: +49-711-1759911
Email: Ansgar.Maisch@DaimlerChrysler.com

Source: Based on information from PEIT