HEAVY VEHICLE BRAKING USING FRICTION ESTIMATION FOR CONTROLLER OPTIMZATION

Other conference contribution, 2018

A novel electronic brake system (EBS) has demonstrated a 17 percent reduction in stopping distance on a tractor semi-trailer combination during vehicle tests in low friction conditions relative to a modern EBS. Even though these results were promising, it was observed that the novel EBS required more information about the road surface to achieve optimal braking performance. In this paper, the development of an on-line friction estimation method for heavy vehicles, as well as an optimization method that can be used to adjust the slip controller settings, according to the road friction, is described. Results from both simulation and real testing of a Volvo 8x4 FMX truck showed that real-time friction estimation is feasible and increased braking performance can be achieved. Simulation results have shown a reduction in braking distance of up to 20 percent on most road surfaces, as well as a reduction in air usage in most cases.