A Braking Force Distribution Strategy in Integrated Braking System Based on Wear Control and Hitch Force Control

A braking force distribution strategy in integrated braking system composed of the main braking system and the auxiliary braking system based on braking pad wear control and hitch force control under non-emergency braking condition is proposed based on the Electronically Controlled Braking System (EBS) to reduce the difference in braking pad wear between different axles and to decrease hitch force between tractors and trailers. The proposed strategy distributes the braking force based on the desired braking intensity, the degree of the braking pad wear and the limits of certain braking regulations to solve the coupling problems between braking safety, economical efficiency of braking and the comfort of drivers. Computer co-simulations of the proposed strategy are performed. The braking force distribution strategy is verified under condition of equal wear of braking pad, condition of greater wear on the front axle of tractor and condition of greater wear on the rear axle of the tractor. The simulation results show that the proposed strategy balanced the braking pad wear by regulating the braking cylinder pressure of each axle and ensured the same braking distance under different wear conditions of braking pad. Under unloaded or loaded conditions, each axle braked according to the desired braking intensity and reached the control objective that the same braking pedal opening rate is in accord with the same braking intensity. Under different load conditions, the strategy ensured the same braking distance and reduced the hitch force, which definitely enhanced the braking safety, economical efficiency of braking and the comfort of drivers.