Page 405 - Understanding Automotive Electronics

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11 FUTURE AUTOMOTIVE ELECTRONIC SYSTEMS

taken a trip to an unfamiliar location understands the problem of navigation.
The driver must first obtain maps having sufficient detail to locate the
destination. Along the trip the driver must be able to identify the car location in
relationship to the map and make decisions at various road intersections about
the route continuation.
There has been considerable research done into the development of an
electronic automatic navigation system, which may someday lead to the
widespread commercial sale of such a system. Although stand-alone
electronic navigation systems with multiscale electronic maps have been
commercially available for some time, these are somewhat less complex
than the concept considered here. The present concept assumes a
multisensor system that optimally integrates position and car motion data
from the various sensors to obtain the best possible estimate of present
position.
Figure 11.18 is a block diagram showing the major components of a
generic automatic navigation system. The display portion of a research system is
typically a CRT. This display depicts one of many maps that are stored in
memory.
Ideally, the display device should have the capability of displaying maps
with various levels of magnification. As the car approaches its destination, the
map detail should increase until the driver can locate his or her position within
an accuracy of about half a block.
The map database must be capable of storing sufficient data to
construct a map of an entire region. For example, data could be stored on
floppy disks (one for each region of the country) that are read into computer

Figure 11.18
Generic Automatic
Navigation System

FPO

392 UNDERSTANDING AUTOMOTIVE ELECTRONICS