Reducing Brake Steer Which Causes Vehicle Drift during Braking 2019-26-0072

Brake steer is an undesirable phenomenon where a vehicle deviates to one side of the road during braking. Vehicle deviation i.e. drift causes driver discomfort, where a driver has to constantly apply Steering Wheel corrections while braking in order to safely maintain the desired path.

In a particular model of commercial vehicle segment, an issue of unacceptable right-side vehicle drift during braking was observed which was making the drive of the vehicle unsafe for the driver. Aim of this paper is to analyse the probable causes of such a vehicle drift, to objectively measure actual vehicle drift during braking using a unique methodology. In this paper, the root cause of the brake steer is discussed and an improvement on the vehicle is proposed by changing kinematic hard points of suspension and steering linkage to reduce the brake steer to the limit that vehicle drift is almost eliminated, and vehicle becomes completely safe for the driver to drive. Multibody Simulation (MBD) is carried out and the results of iterations other than optimum are also presented in the paper to compensate for design trade-offs.

To validate the results, vehicle drift measurement was carried out on the problematic model of commercial vehicle segment and the results are discussed along with the optimum design change implemented to overcome the phenomenon of vehicle drift during braking.