Page 399 - Understanding Automotive Electronics

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11 FUTURE AUTOMOTIVE ELECTRONIC SYSTEMS

signal and passes it to the signal processor, also directly powered by the car
battery. The signal processor then activates a warning lamp for the driver, and
it remains on until the driver resets the warning system by operating a switch
on the instrument panel.
One reason for using a signal processing unit is the relatively short life of
the transmitter battery. The transmitter will remain on until the low-pressure
condition is corrected or until the battery runs down. By using a signal
processor, the low-pressure status can be stored in memory so the warning will
still be given even if the transmitter quits operating. The need for this feature
could arise if the pressure dropped while the car was parked. By storing the
status, the system would warn the driver as soon as the ignition was turned on.
Many other concepts have been proposed for providing a low tire pressure
warning system. The future of such a system will be limited largely by its cost
and reliability.
INSTRUMENTATION
The reduced cost of It is very likely that some interesting advances in automotive
VLSI and microproces- instrumentation will be forthcoming, such as certain functions, new display
sor electronics is result- forms including audible messages by synthesized speech, and interactive
ing in advanced communication between the driver and the instrumentation. These advances
instrumentation and the will come about partly because of increased capability at reduced cost for
use of voice synthesis in modern solid-state circuits, particularly microprocessors and
warning systems. microcomputers.
One of the important functions that an all-electronic instrumentation
system can have in future automobiles is continuous diagnosis of other on-
board electronic systems. In particular, the future computer-based electronic
instrumentation may perform diagnostic tests on the electronic engine control
system. This instrumentation system might display major system faults and
even recommend repair actions.
Another function that might be improved in the instrumentation system
is the trip computer function. The system probably will be highly interactive;
that is, the driver will communicate with the computer through a keyboard or
maybe even by voice.
The full capabilities of such a system are limited more by human
imagination and cost than technology. Most of the technology for the systems
discussed is available now and can be packaged small enough for automotive
use. However, in a highly competitive industry where the use of every screw is
analyzed for cost-effectiveness, the cost of these systems still limits their use in
production vehicles.
Heads Up Display

In the first edition of this book, it was speculated that CRT displays
would appear in production cars. This has, in fact, occurred, and there is a

386 UNDERSTANDING AUTOMOTIVE ELECTRONICS