Improved Crash Avoidance Using Performance-Based Brake Test Results 1999-01-0822

Current crash avoidance systems combine vehicle speed with knowledge of position (and change in position) of potential obstacles in front of the vehicle to trigger alarms warning of impending collisions. The various alarm levels are triggered using a simple set of minimum time delays. Although knowledge of on-board vehicle braking capability is not currently incorporated into these systems, such knowledge can improve the effectiveness of crash avoidance systems. A round robin test series of performance based brake testers (PBBTs) was conducted in which the brake forces on several configurations of control vehicles were measured. Using the PBBT-reported brake forces and vehicle weights, combined with knowledge of limiting tire/road coefficient of friction, the maximum deceleration potential can be determined and incorporated into on-board crash avoidance systems. This paper presents the results of the PBBT round robin tests and shows how the information obtained with a PBBT can be incorporated in the algorithms used to warn of impending collisions and minimize the risk of unstable braking.