Development of Autonomous Emergency Braking control system based on road friction

Autonomous emergency brake (AEB) is one of important vehicle active safety function to avoid or mitigate collision. In general, the AEB system employs a Time-To-Collision (TTC) to measure the potential danger of impact into obstacles. Once the TTC is smaller than desired threshold, the AEB would activate the braking system. The threshold of TTC for braking is designed based on assuming road friction to be a constant. However, the actual road condition is intricate and changed at any time. Therefore, an AEB strategy considering the effect of different road friction on the braking threshold of TTC is developed. First, a combined-slip tire model is used to estimate peak road friction. The estimated peak road friction is then used to obtain braking threshold of TTC. Since the road friction can be identified in real-time, the proposed AEB algorithm can adapt to different road surface. The simulation results show that proposed control strategy has batter performance than that of the conventional one.