Tire-induced vehicle pull

Abstract: Vehicle pull is an issue that occurs when the driver has to exert a discerniblesteering torque (pull) for the vehicle to run straight, otherwisea lateral drift takes place. This thesis deals with the straight motion ofroad vehicles, with particular focus on the role played by tire characteristics,road cross slope and interactions between tires and vehicle.A thorough theoretical approach has been adopted, adjusting thePacejka’s formulation for effective axle characteristics and extendingthe linear handling diagram theory. This has allowed to obtain innovativeanalytical expressions, describing the straight-driving slip anglesand steering torque offsets.The analytical expressions have been validated, together with asingle-track model, by means of quasi-static and dynamic simulationsof a full-vehicle model. Moreover, a relationship between tire characteristicsand on-center handling has been described, that relates objectivemetrics with subjective feedback.The obtained analytical expressions can be used by vehicle OriginalEquipment Manufacturers (OEMs) or Tire Suppliers for productdevelopment.