Image Processing Reference
In-Depth Information
13
Trends in Automotive
Communication Systems
. Automotive Communication Systems: Characteristics
andConstraints ......................................
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From Point-to-Point to Multiplexed Communications
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Car
Domains and heir Evolution
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Different Networks for
Different Requirements
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Event-Triggered versus TT
. In-CarEmbeddedNetworks .........................
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Priority Buses
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Time-Triggered Networks
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Low-Cost
Automotive Networks
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Multimedia Networks
. MiddlewareLayer....................................
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. Open Issues for Automotive Communication
Systems ..............................................
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Optimized Networking Architectures
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System Engineering
References .................................................
Nicolas Navet
INRIA—RealTime-at-Work
Françoise Simonot-Lion
LORIA—University of Nancy
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13.1 Automotive Communication Systems: Characteristics
and Constraints
13.1.1 From Point-to-Point to Multiplexed Communications
Since the s, one observes an exponential increase in the number of electronic systems that have
gradually replaced those that are purely mechanical or hydraulic. The growing performance and
reliability of hardware components and the possibilities brought by software technologies enabled
implementing complex functions that improve the comfort of the vehicle's occupants as well as their
safety. In particular, one of the main purposes of electronic systems is to assist the driver to control the
vehicle through functions related to the steering, traction (i.e., control of the driving torque), or brak-
ing such as the anti-lock braking system (ABS), electronic stability program (ESP), Electric Power
Steering, active suspensions, or engine control. Another reason for using electronic systems is to
controldevicesinthebodyofavehiclesuchaslights,wipers,doors,windows,and,recently,entertain-
ment and communication equipments (e.g., radio, DVD, hand-free phones, and navigation systems).
In the early days of automotive electronics, each new function was implemented as a stand-alone
electronic control unit (ECU), which is a subsystem composed of a microcontroller and a set of sen-
sors and actuators. his approach quickly proved to be insufficient with the need for functions to be
distributed over several ECUs and the need for information exchanges among functions. For example,
the vehicle speed estimated by the engine controller or by wheel rotation sensors has to be known
to adapt the steering effort, to control the suspension, or simply to choose the right wiping speed.
