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From: rhaar@rcsac2.uucp (Bob Haar CS50)
Newsgroups: sci.electronics
Subject: Re: CARNET - Automotive Electronics
Message-ID: <32471@rphroy.UUCP>
Date: 29 Aug 90 13:03:13 GMT
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Organization: GM Research Labs, Warren, MI
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Newsgroups: sci.electronics
Subject: Re: CARNET - Automotive Electronics
Summary: 
Expires: 
References: <7591@scolex.sco.COM>
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Reply-To: rhaar@rcsrlh.UUCP (Bob Haar CS50)
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Organization: GM Research Labs, Warren, MI
Keywords: Automotive Electronics Computers Mobile Power Systems Communications

In article <7591@scolex.sco.COM> deanr@sco.COM (Dean Reece) writes:

>Please, no flames for how silly this may sound;  At this point I'm just
>doing research and trying to learn some specifics about the idea.  The
>basic scope of the idea is as follows:
>
>To replace the entire wiring warness (control and sensing circuits) with
>a network controlled by a central computer.

Before you go much farther with this, I have two suggestions:

1) This discussion should at least be cross-posted to rec.autos.tech - a 
news group set up for technical discussions of automotive issues.

2) Check out what is already happening in the automotive world. Much of
what you suggest is already is place or in the works.

Vehicle manufacturers have been using proprietary networks in cars for
about ten years. For example, GM has two distinct networks in use, one
for connection engine controllers to body controllers, etc. and another
used within the entertainment and comfort systems. Other car makers are
using their own systems. Since these are proprietary, I cannot say
much about them here.

For the past four or five years, the Society of Automotive Engineers (SAE)
has been working on industry wide standards for in-vehicle networks. There
is one recommended practice (sort of a working standard) in place now
that will be in production in 1994. This is referred to by its document
number (J1850). J1850 is aimed at linking computer-based modules that 
exchange information but don't do time-critical control over the link.

J1850 is being required by the Calif. Air Resources Board for all vehicles
in California for diagnosing emission equipment starting in 1994.       

SAE also has work going on looking at protocols for load-control mulitplexing
(commanding simple actuators such as lights) and high-speed protocols for
real-time control such as active suspensions and traction control.

Many papers have been published within SAE on these topics. Besides the
automotive people, a number of electronics companies have been active
in this effort - e.g. Intel, Motorola, and TI.

Similar efforts are under way in Europe (under ISO) and Japan (JSAE), but
with different motivations and directions.

If there is interest, I can post some articles describing these efforts
in more detail. I am a member of the SAE Vehicle Networking Committee and
as a computer scientist at GM, I work with distributed architectures
for vehicle control.


--
	Bob Haar   CSNET: HAAR@GMR.COM  UUCP: uunet!edsews!rphroy!rcsac1!rhaar
	Computer Science Dept., G.M. Research Laboratories
DISCLAIMER: Unless indicated otherwise, everything in this note is
personal opinion, not an official statement of General Motors Corp.