Page 414 - Understanding Automotive Electronics

2735 | CH 11 Page 401 Tuesday, March 10, 1998 1:30 PM

FUTURE AUTOMOTIVE ELECTRONIC SYSTEMS 11

ADVANCED DRIVER INFORMATION SYSTEM

One of the areas having the greatest potential payoff for electronics in
automobiles is in the relationship of the car and driver to the road.
Improvements in traffic flow in congested areas might be possible if the driver
has information concerning traffic problems on the road ahead.
In an attempt to improve traffic flow, particularly on congested routes
near large metropolitan areas, a government program has been established that
has come to be known as the intelligent transportation system (ITS). As of the
time of this writing, roughly $1 billion has been invested with cooperative
investment from the transportation industry. The general aim of this project
has been to improve the safety, efficiency, capacity, and environmental quality
of the existing highway transportation system.
The concept involves building an infrastructure supported by on-board
vehicle electronics to evaluate traffic flow in an area and to communicate to
drivers recommendations for improved routing as well as timely messages
concerning traffic tie-ups and safety-related warnings. Included in the required
hardware for the system are sensors for measuring existing traffic flow, very
large, high-power computers for processing data and for generating the
appropriate messages, as well as communications systems and automotive
displays.
Although the long-term capabilities for ITS are unclear, the short-term
application of technology will probably be in the form of an advanced driver
information system. One of the most likely candidates is a radio message service
system utilizing a portion of the bandwidth allotted to commercial FM radio
stations (in the same spectrum used to transmit Muzak). This system requires a
special FM receiver equipped with a decoding system. Whenever it is
appropriate (e.g., for road emergencies or traffic congestion), a message is
transmitted by the FM stations in the area. In one scheme, the radio receiver is
automatically retuned to a special frequency on which voice messages are
transmitted identifying the problem to the driver.
One very interesting experimental system having great potential for future
ITS application is the system called TELEPATH that was developed by Delco.
This system serves as an example of an ITS system in that it is representative of
features that are likely to be found in future cars, although the exact
architecture for any particular vehicle could well be different than the present
example.
A block diagram of this system, shown in Figure 11.24, is built around
the digital data bus described in Chapter 9. This system supports a number of
subsystems, including Global Positioning System (GPS) navigation, a keyless
entry, vehicle-to-roadside communication (VRC), a digital audio broadcast
(DAB) entertainment system, and a radio data system (RDS) that also serves as
a communication link for a differential GPS augmentation data channel and a
cellular phone. Other inputs to the navigation and communications computer

UNDERSTANDING AUTOMOTIVE ELECTRONICS 401