Various radar systems have been proposed as collision avoidance
sensors for automatic braking and warning applications. Practical
use of laser radar systems is near with the introduction of high
power, high reliability laser diodes.
Utilizing these new devices, a laser radar system has been
adapted for measuring the distance to objects in its path. It was
first shown that reflectors on the rear of the automobile possess
high reflectivity and sharp directivity. Given these
characteristics, a compact laser radar system was tested that
employed 12W laser diodes and PIN photodiodes.
The maximum range of approximately 100 m was obtained.
Furthermore, the ability to discriminate other vehicles from
roadside objects was achieved by detecting discontinuity in
measured distance data through a microprocessor. These results show
that the performance of laser radar is comparable to that of
microwave radar. Considering the cost and size of the radar
systems, laser radar would appear to be the more practical of the
Hiroshi Kawata, Hiroshi Endo, Yoshiyuki Eto
Nissan Motor Co., Ltd.
International Technical Conference on Enhanced Safety of Vehicles