Automated Control and Brake Strategies for Future Crash Avoidance Systems - Potential Benefits 2013-01-2391

This paper explores the potential safety performance of “Future Generation” automated speed control crash avoidance systems for Commercial Vehicles. The technologies discussed in this paper include Adaptive Cruise Control (ACC), second and third generation Forward Collision Avoidance and Mitigation Systems (F-CAM) comprised of Forward Collision Warning (FCW) with Collision Mitigation Braking (CMB) technology as applied to heavy trucks, including single unit and tractor semitrailers.

The research [1[ discussed in this paper is from a study conducted by UMTRI which estimated the safety benefits of current and future F-CAM systems and the comparative efficacy of adaptive cruise control. The future generation systems which are the focus of this paper were evaluated at two separate levels of product refinement, “second generation” and “third generation” systems. Second generation systems have the capability of reacting to fixed vehicles which were not moving prior to the engagement of the radar and include CMB nominal brake deceleration of 0.35g. Third generation systems to react to fixed vehicles as well but with a substantially more aggressive CMB brake deceleration capability of 0.6 g. The ACC system was evaluated with two levels of foundation brake performance, −0.25 g and −0.6 g

The functional characteristics of a prototype future F-CAM system were evaluated and its performance generically modeled in the context of second generation and third generation attributes to estimate potential safety benefits. This was accomplished through the following steps: (1) first characterize the actual performance of the prototype future system in various pre-crash scenarios under controlled test track conditions, and then reverse engineering the algorithms that control warnings and automatic braking actions and adding second and third generation performance characteristics; (2) developing a comprehensive set of simulated crash events representative of actual truck striking rear-end crashes. This virtual “reference” crash database was developed by analyzing vehicle interactions (or conflicts) from naturalistic data to create thousands of crashes in a computer simulation environment; (3) overlaying the F-CAM generic algorithms onto the simulations of each crash event and observe the kinematic impacts (i.e., benefits) from having initiated warnings and/or automatic braking (including reduction in impact speed, or elimination of the crash).

The crash population that could likely benefit from the technologies was identified using nationally representative crash databases. The results from the simulation studies were applied to the national crash population and are presented in terms of crashes avoided, reductions in fatalities, injuries and property damage.