DETROIT - A consortium of five European automakers, a Swedish software maker and computer chip maker Motorola want to streamline wiring in automobiles.
The group proposes a one-wire system to run the many small motors, sensors and electronics in a vehicle chassis.
The consortium says its new Local Interconnect Network standard for electronics eliminates the multiple-wire harnesses, printed circuit boards and analog switches that abound in door, steering wheel and instrument panel modules.
The network's single wire allows digitally encoded software signals to address 'mechatronic' devices - such as a power window motor with built-in electronics - rather than using several wires to run different functions of the motor. The network also would use just one type of connector for every component, simplifying assembly and testing and making it possible to easily plug in new devices in a vehicle during its life cycle.
A new standard?
The network is being proposed as an 'open standard.' Programming and system details would be available to any company willing to follow its specifications.
Typical applications for a Local Interconnect Network bus connection are units such as doors, steering wheels, seats, climate control, lighting or chassis sensors. In a door system design, 'We are saving up to 30 wires, a lot of connectors and also printed circuit boards,' said Denis Griot, general manager of Motorola's Body Electronics & Occupant Safety Division.
'We want to reduce costs by decreasing the manifold of existing bus-end solutions,' said Karlheinz Baier, DaimlerChrysler representative to the consortium. The network will be used on a Mercedes-Benz instrument panel in calendar year 2001 and later in a steering wheel assembly.
Other automakers in the group include Audi, BMW, Volvo and Volkswagen. Audi intends to use the network in a roof module to power a sunroof and rain sensors beginning in 2002.
Too soon to commit
North American suppliers, including Lear Corp. and Johnson Controls, are aware of the so-called 'LIN bus' but have not moved to adopt it yet. Executives interviewed at the SAE 2000 World Congress said standards continue to emerge, but technology is moving so rapidly that committing to any one is premature without clear signals that automakers plan to use it.
The Local Interconnect Network standard is not the first attempt to simplify and control vehicle electronics. A standard named Controller Area Network is used in two different forms to run critical systems such as engine control, airbags and safety devices. Controller Area Network connection nodes are too expensive to use throughout a vehicle, though, and the system also requires two wires to run each device. The cost of communicating with such devices by Local Interconnect Network will be two to three times lower than comparable Controller Area Network connections, consortium members said.
Said Baier: 'What we want to have is a network below CAN that can be reached with LIN.'
