Design of a Dynamic Brake Force Regulation Strategy for Heavy Commercial Road Vehicles

This paper presents a dynamic brake three distribution (BFD) control strategy that allocates the brake force to each wheel based on the normal loads and coefficients of friction for a two-axle heavy commercial road vehicle (HCRV) for straight-line braking. A three degree of freedom half car pitch model was used to calculate the dynamic load transfer on each wheel, which was corroborated using IPG TruckMaker. The Magic Formula tire model with load-dependent coefficients was utilized to obtain instantaneous coefficient of friction at all four tires. The BFD strategy was then compared with two static BED strategies: one which employs a 50:50 BED and another which employs a BED corresponding to ideal BED curve (I curve) for the fully laden vehicle between the front and rear wheels. The test cases for a comparative evaluation of the dynamic and static BED strategies were generated from the IS 11852 standard. The dynamic BED strategy was found to reduce braking distance in the range of 1 % to 27 % when compared to the static BED strategies. Further, all the strategies resulted in stable braking with no wheel lock.