TABLE OF CONTENTS Longitudinal sensing and control systems address situations pertaining to the forward and rearward movement of the vehicle. Drivers are assisted in perceiving and responding to obstacles, traffic, and road conditions to avoid crashes.
When parking, basic rear sensing systems help the driver avoid minor bumps and scratches, while more advanced systems are expected to have the perceptiveness to detect dangerous situations, such as small children out of view of the driver. On the open road, the driver s perception is enhanced through systems such as night vision and adaptive headlights. Beginning with ACC, forward sensing systems help drivers perceive the situation ahead of the vehicle to assist in following other traffic as well as in avoiding crashes.
In fact, forward sensing systems build upon one another. ACC constitutes the initial foray into forward sensing, which opens up the possibility of using the ACC sensor for forward collision warning and precharging of the brakes when a collision is imminent. Higher performance forward sensors support active braking to mitigate crashes, with the eventual possibility of avoiding most forward crashes altogether.
Forward collision countermeasures have actually been with us since the late 1980s, starting with systems on heavy trucks. Automotive systems for convenience (i.e., ACC) came along in 1997, with safety-focused systems being introduced only recently. There is also interest in equipping transit buses with these collision countermeasures. While the business case for transit buses may not be strong in general, just one tragedy in a city can spur equipping an entire fleet.
