How soon to brake and how hard to brake: Unified analysis of the envelope of opportunity for rear-end collision warnings 2001-06-0126
Rear-end collision warning systems are both an available and an
evolving technology. The goal of these systems is to alert the
driver of a dangerous situation, with sufficient time to take
evasive action and avoid a collision. Their development, analysis,
and evaluation requires considering the envelope of opportunity
available to a driver - once an alert is issued - to avoid a
collision.
This paper simplifies the envelope of opportunity analysis and
presentation. Previous work in this area focuses on establishing
the relevant kinematic equations of motion and obtaining
case-specific plots of the envelope of opportunity. We have plotted
the envelope of opportunity using the reaction time and the
reciprocal of the following vehicle acceleration. Plotting the
envelope in this manner readily accommodates the limiting cases of
infinite following vehicle deceleration and zero reaction time and
the envelope of opportunity is, in most cases, a straight line,
allowing for direct generation of the envelope and insight into the
effect of initial kinematic variables on the envelope.
Author(s):
Bruce H. Wilson
Affiliated:
Volpe National Transportation Systems Center
Pages: 10
Event:
International Technical Conference on Enhanced Safety of Vehicles
Related Topics:
Collision warning systems
Reaction and response times
Kinematics
Vehicle acceleration
Vehicle drivers
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