Enhancement of ABS Performance through On-Board Estimation of the Tires' Response by Means of Smart Tires

Active controls for braking dynamics are widely investigated in literature [1]-[8] as one of the way to improve vehicle safety and avoid collisions. Active systems commonly mounted on passenger cars like ABS/EBD, have achieved a high level of robustness towards possible changes in the tires' characteristics due to multiple causes such as: under-inflation, wear and also replacement of tires with new ones different from the first equipment series. Although these electronic control systems have been designed to be robust and no case-sensitive to such variations in tire conditions, a further improvement of their performance could be achieved by means of a continuous adaptive control.

This paper explores the opportunity of optimizing the performances of ABS control system through an on-board identification of the tires' response; in particular the real-time estimation of the contact forces provided by ‘Smart Tires’ [3][4][9] joined with measurements available on CAN network, allows to evaluate the response of the tires in terms of longitudinal force/longitudinal slip relation. ABS parameters could be thus adjusted in order to adapt the control strategy to changes in the tires' characteristics. Tires' parameters identification is validated experimentally through different braking tests on straight track for different loads and inflation pressures. The performances of the optimized control system are then numerically evaluated through a validated 14 d.o.f. vehicle model.