The Response Characteristics of Several Vehicles Equipped with Electronic Stability Control to Violent Steering Demands on Different Surfaces

In this study, tests were performed on eight different vehicles, each equipped with a version of electronic stability control (“ESC”). Tests performed on a dry test surface included a 1999 two door sports car, a 2000 four door sedan, a 2002 four door sedan, a 2003 large rear wheel drive sport utility vehicle, and a 2002 five door hatchback. Tests performed on a wet surface were isolated to a full size rear wheel drive sport utility vehicle. Tests performed on a snow and ice covered surface included a 2003 mid size sport utility vehicle, a 2002 full size sport utility truck, and a 2007 mid size sport utility vehicle; all from different manufacturers. This selection allowed for the evaluation of different ESC systems and strategies on various surfaces to violent steering demands. The steer inputs were applied to the vehicles manually by test drivers and were purposely selected to generate large displacements so that the ESC systems would activate. The purpose of this study is to evaluate how ESC systems accommodate large steering demands, not to compare measured attributes with and without ESC enabled. The results of this study confirm and demonstrate that ESC is a promising technology and will benefit drivers in some situations. However, these systems still have to work within the laws of physics. Under certain driving conditions, steering demands can be generated which overwhelm the ability of the ESC systems to keep the vehicle from generating significant side slip angles. This fact does not constitute a problem with the ESC systems or the vehicles tested; it is merely a matter of vehicle dynamics and available tire traction.