Abstract
In this paper it will be studied the vehicle stability when barking on a straight flat road. In this situation the vehicle stability depend on the suspension and steering geometry as well as the brake torque differences between wheels in the same axle.
The study will be focused on one Light Commercial Vehicle with FR & RR leaf springs rigid axle suspension and for the braking system one configuration that is normally used in the majority of these vehicles, front disc brakes and rear drum brakes, with I+H brake circuit.
As a first step it will be drawn a graph in which there will be the brake torque difference measured trough wheel torque, versus the yaw rate measured by a gyroscope, which has been considered the more suitable parameter to measure the vehicle deviation.
In relation to the brake system the study considered that there are no brake torque difference in the REAR axle and has been evaluated the influence in the vehicle pulling to one side for a fixed steering geometry by changing the brake torque difference in the FRONT axle.
It has also been studied the brake torque difference in the FRONT axle and its relation with the rotor disc brake surface finishing, roughness, by using wheel torque.
There are two conclusions of this study, one is the vehicle sensitivity to brake torque differences and the other one the brake torque differences due to difference rotor disc brake surface roughness.
As a result of the first conclusion of this study a new procedure to evaluate the vehicle sensitivity to brake torque differences or vehicle pulling to one side when braking has been made.