According to the North American National Automotive Sampling System Crashworthiness Data System (NASS/CDS), approximately one-half of all accidents during driving are of the secondary collision pattern in which the collision event involves the occurrence of secondary collision. Accidents involving impact to a stopped vehicle (chain-reaction collisions) have increased to approximately 3% of all accidents in North America, and although the rate of serious injury is low, cases have been reported of accidents in which cervical sprain occurs as an after-effect[1]. In order to mitigate these circumstances, research has been conducted on systems of automatic braking for collisions. These systems apply brakes automatically when a first collision has been detected in order to avoid or lessen a second collision.
Research on automatic collision braking systems, however, has not examined the multiple collisions parked [1, 2]. The systems in use applied a fixed amount of braking, approximately 5.88 m/s2 (0.6 G), regardless of the vehicle speed following the first collision. There has been no research into optimum brake control for all situations to the authors' knowledge. The present research addressed this issue using vehicle behavior simulation software to simulate all collision situations and the optimum braking for each.