Image Processing Reference
In-Depth Information
17.2 The Need
The car industry today is implementing an increasing number of functions in software. Complex
electrical architectures using multiple networks, with different protocols are the norm in mod-
ern high-end cars. The software industry in general is handling software complexity through “best
practices” such as
•
Abstraction—hiding the unnecessary level of detail.
•
Composability—partitioning a solution into a set of separately specified, developed, and
validated modules, easily combined into a larger structure inheriting the validity of its
components—without the need for revalidation.
•
Parallel processes—state-of-the-art development processes such as the Rational Unified
Process are based on parallel and iterative development were the most critical parts are
developed and tested in the first iterations.
The automotive industry is under constant pressure to reduce cost and lead time, while still
providing increasing amount of functionality. his must be managed without sacrificing quality. It is
not uncommon today for a car project to spend half a billion U.S. dollars on development and perhaps
as much as million on prototypes. By shortening lead time the car maker creates benefits in several
ways, typically both development cost and capital costs are reduced. At the same time an earlier mar-
ket introduction creates better sales volumes and therefore better profit. One way of reducing lead
time is by eliminating traditional prototype loops requiring full-size cars, rather relying on virtual
development replacing traditional development and testing methods by computer-aided engineering.
To reduce development time while maintaining quality, a reduction in lead time must occur in a
coordinatedfashionforallmajorsubsystemsofacarsuchasbody,electrical,chassis,andengine.
With improved tools and practices for other subsystems and increasing complexity of the electrical
system more focus must be placed on the electrical development process, as it may determine the
total lead time and quality of the car. These two challenges—lead time reduction and handling of
increased software complexity—will put growing pressure on the industry to handle development of
electrical architectures in a more purposeful manner.
17.3 History
The LIN Consortium started in late initiated by five car manufacturers Audi, BMW, Daim-
lerChrysler, Volvo and Volkswagen, the tool manufacturer Volcano Communications Technology,
and the semiconductor manufacturer Motorola. he workgroup focused on specification of an open
standard for low-cost LINs in vehicles where the bandwidth and versatility of CAN is not required.
The LIN standard includes the specification of the transmission protocol, the transmission medium,
the interface between development tools, and the interfaces for application software programming.
LIN promotes scaleable architectures and interoperability of network nodes from the viewpoint of
hardware and software, and a predictable electromagnetic compliance (EMC) behavior. LIN com-
plements the existing portfolio of automotive multiplex networks. It will be the enabling factor for
the implementation of hierarchical vehicle networks, in order to gain further quality enhancement
and cost reduction of vehicles. It addresses the needs of increasing complexity, implementation, and
maintenance of software in distributed systems by provision for a highly automated tool chain.
he main properties of the LIN bus are
•
Single master multiple slaves structure
•
Low-cost silicon implementation using common universal asynchronous receiver trans-
mitter (UART)/serial communication interface (SCI) interface hardware, an equivalent
in software, or as pure state machine
