Influence of Asymmetrical Design Parameter on Vehicle Pull During Brake Application 2021-26-0354

The steering system of commercial vehicle is asymmetrical to left side and rightside, this causes vehicle pull during braking application. This directly affects the safety of the driver and vehicle ride & handling performance. In a similar way, the asymmetrical suspension parameter unintentionally set during vehicle assembly arealso major contributors for creating a vehicle pull. After application of brake force, the tire contact patch creates a moment about the kingpin axis. However, this moment generated is different on left and right-side due to asymmetrical design parameters resulting in vehicle deviation from its intended path. A large deviation may lead to on road accidents. Some of the major factors which are responsible for the vehicle pulling phenomenon are the asymmetrical steering system compliance, asymmetrical suspension geometry, tire, braking system, road camber etc.

The present work is useful to analyze the effect of change (left to right side) in the asymmetrical Steering wheel parameter on vehicle pulling at the early stage of vehicle development. On production vehicles, it is practically not possible to achieve the same parameter on both sides. Therefore, it is important to predict the vehicle response to these variations and how does it affect vehicle handling characteristics.

A full vehicle model is built with different vehicle subsystems in MSC ADAMS/Car. The Vehicle dynamic Simulation were conducted to measure the amount of vehicle pulling by application of brake force on each wheel. This model acts as input to ADAMS/Insight® for DOE study. The systematic DOE study is carried out to check the impact of different parameters i.e., cross camber, cross caster, cross toe, and cross scrub radius, on the vehicle behavior during different braking conditions. Based on this DOE Study the influence of each parameter is estimated on vehicle stability during straight-ahead braking.